U.S. patent application number 16/313177 was filed with the patent office on 2019-08-01 for exoskeleton and master.
The applicant listed for this patent is Marcel REESE. Invention is credited to Marcel REESE.
Application Number | 20190232485 16/313177 |
Document ID | / |
Family ID | 59366361 |
Filed Date | 2019-08-01 |
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United States Patent
Application |
20190232485 |
Kind Code |
A1 |
REESE; Marcel |
August 1, 2019 |
EXOSKELETON AND MASTER
Abstract
The invention relates to the improvement of exoskeletons and
masters thereof and to their use in teleoperative applications in
virtual worlds or the real world. Non-actuated exoskeletons can be
used to transfer loads from the user, for example, heavy luggage,
tools or also the body weight of the user, to the ground and to
relieve the joint and muscle system of the user. This can increase
the endurance and also effective strength of the user.
Motor-driven, actuated exoskeletons can be used in different
fields. They can be worn as a freely moveable robotic suit which
comprises a built-in energy supply and electronic control. They can
also be used to improve the force and endurance of a user whilst
the user moves in an unlimited environment. Another use of the
fixed exoskeleton is in the field of interaction with virtual
worlds or for controlling real robots. In this instance, an
exoskeleton can be used to establish a teleoperative connection
between the user and the master (virtual avatar or real robot). The
user users the exoskeleton to directly transfer control commands to
the master. The elements of the user and the master then
practically carry out the same movements synchronously. The aim of
the invention is to improve exoskeletons and masters of the
mentioned type and the associated control units. This can, in
particular, be achieved by a favorable realization of rotational
axes which define rotational movements of different elements which
to a large extent perform a hip movement.
Inventors: |
REESE; Marcel; (Bielefeld,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
REESE; Marcel |
Bielefeld |
|
DE |
|
|
Family ID: |
59366361 |
Appl. No.: |
16/313177 |
Filed: |
June 27, 2017 |
PCT Filed: |
June 27, 2017 |
PCT NO: |
PCT/EP2017/000744 |
371 Date: |
April 11, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B25J 9/0057 20130101;
B25J 9/0048 20130101; A61H 2201/1652 20130101; A61H 2201/165
20130101; A61H 2201/163 20130101; A61H 1/0237 20130101; A61H
2201/1645 20130101; B25J 9/0006 20130101; B25J 9/104 20130101; B25J
17/00 20130101; A61H 2201/1623 20130101; A61H 2201/1659 20130101;
A61H 1/0262 20130101; B25J 9/0069 20130101; A61H 3/00 20130101;
A61H 2003/007 20130101 |
International
Class: |
B25J 9/00 20060101
B25J009/00; B25J 17/00 20060101 B25J017/00; A61H 3/00 20060101
A61H003/00; A61H 1/02 20060101 A61H001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 27, 2016 |
DE |
10 2016 007 741.7 |
Claims
1. Device (1000) including a first member (80a, 80b), a second
member (82), a third member (84), and a fourth member (86), wherein
the first member (80a, 80b) is connected to a first rotary joint
(81) via which the second member (82) is rotatably supported about
a first axis (93), the second member (82) is connected to a second
rotary joint (83) via which the third member (84) is rotatably
supported about a second axis (94), the third member (84) is
connected to a third rotary joint (85) via which the fourth member
(86) is rotatably supported about a third axis (95), the axes (93,
94, 95) pass substantially through a common point (91) and the
first axis (93) with the second axis (94) forms a first angle
(.phi..sub.1) and the second axis (94) with the third axis (95)
forms a second angle (.phi..sub.2).
2. Device according to claim 1, characterized in that the first
axis (93) is substantially perpendicular to the main plane of the
first element (80a, 80b).
3. Device according to claim 1, characterized in that the first
axis (93) is rotated about a vertical axis passing through the
common point (91) by a third angle (.alpha.) with a value unequal
to zero.
4. Device according to claim 1, characterized in that the first
axis (93) is rotated about a horizontal axis passing through the
common point (91) by a fourth angle (.beta.) with a value unequal
to zero.
5. Device according to claim 1, characterized in that the first
angle (.phi..sub.1) has a value in the range of 25-45 degrees and
preferably 35 degrees.
6. Device according to claim 1, characterized in that the second
angle (.phi..sub.2) has a value in the range of 60-80 degrees and
preferably 70 degrees.
7. Device according to claim 1, characterized in that the third
angle (.alpha.) and/or the fourth angle (.beta.) has a value in the
range of 10-30 degrees and preferably 20 degrees.
8. Device according to claim 1, characterized in that the sum of
the first angle (.phi..sub.1) and the second angle (.phi..sub.2) is
in the range of 85-120 degrees and the first angle (.phi..sub.1) is
in the range of 15-45 degrees.
9. Device according to claim 1, characterized in that at least one
of the elements (82, 84, 86) is subdivided into at least two
sub-elements (82a, b, c) and adjacent ones of these sub-elements
(82a, b, c) are rotatably connected to each other, respectively
about an axis (94a, 94b, 94c), these axes passing substantially
through the common point (91).
10. Device also according to claim 1, characterized in that a fifth
element (90; 9000) is rotatably mounted about a further axis (910)
and has a surface (904) which runs substantially parallel to the
further axis (910), this surface (904) having, at least on its side
remote from the axis (910), a profile which corresponds to at least
two circular segments with different radii.
11. Device according to claim 10, characterized in that the circles
belonging to said circle segments have their centers in the
vicinity of the user and/or are parallel to the frontal plane of
the user.
12. Device also according to claim 1, characterized in that
fastening means are provided which are designed and arranged in
such a way that a user can preferably be firmly connected with his
hip, his torso and/or his thighs to at least one of the elements
(80a, 80b; 82; 84; 86; 90) and/or to parts of a back plate.
13. Device according to claim 12, characterized in that the
fastening means comprise straps, shells and/or harness.
14. Device according to claim 12, characterized in that the
fastening means are designed and arranged such that the user is
connected to the first element (80a, 80b).
15. Device according to claim 12, characterized in that the
position of the fastening means can be changed by adjustment
means.
16. Device according to claim 12, characterized in that the force
carried by the fastening means can be varied by adjustment
means.
17. Device according to claim 16, characterized in that the force
carried by the fastening means can be measured and influenced by
means of the adjustment means and a control loop.
18. Device according to claim 1, characterized in that means are
provided suitable to move the foot surface (904) relative to the
user.
19. Device according to claim 1, characterized in that the
fastening means are designed and controllable in such a way that
they can be relaxed or moved and thus the degree of relief can be
changed.
20.-25. (canceled)
26. Device also according to claim 1, characterized in that a
rotation unit (211) is provided with a first rotational member
(200) rotatably mounted about a first rotational axis (205), a
second rotational member (201) rotatably mounted to said first
rotational member (200) about a second rotational axis (206), a
third rotational member (202) rotatably mounted to said second
rotational member (201) about a third rotational axis (207), an
exoskeleton (203) rotatably mounted to the third rotation element
(202) about a fourth rotation axis (208).
27. Device according to claim 26, characterized in that the mount
between the exoskeleton (203) and the third rotational element
(202) is arranged in neutral position above the connection between
the third rotational element (202) and the second rotational
element (201).
28. Device according to claim 26, characterized in that in-between
the exoskeleton (203) and the third rotary element (202) a back
mount (204) is arranged.
29. Device according to claim 26, characterized in that the
exoskeleton (203) and/or its working space and/or its back mount
(204) and/or a user fixed to the exoskeleton (203) collides with
other parts of the device during a complete 360 degree rotation
about the fourth axis of rotation (208).
30. Device according to claim 29, characterized in that mechanical
and/or electrical means are provided, such as mechanical or
electronic limiters and/or suitably designed components such as
axles, gears, bearings and/or motors, which limit the range of
rotation of the exoskeleton (203) about the fourth axis of rotation
(208) in such a way that a collision of the exoskeleton (203)
and/or its working space and/or its back mount (204) and/or a user
fastened to the exoskeleton (203) with other parts of the system is
avoided.
31. A device according to claim 1, characterized in that at least
one further rotational element is rotatably mounted between the
third rotational element (202) and the exoskeleton (203) and/or
back mount (204) at both ends, which cannot be rotated 360 degrees
about the further axes of rotation without colliding with the
exoskeleton (203).
32. Device also according to claim 1, characterized in that at
least two actuators (304a-304f) are provided which are connected
with a first side to a solid base (303) and are connected with a
second side to a working platform (302), whereby an exoskeleton
(300) is mounted to the working platform (302) by means of a
mounting element (301).
33. Device according to claim 32, characterized in that between the
second side of at least one of the actuators (304a-304f) and the
working platform a support (305a-305c) is arranged.
34. Device also according to claim 32, characterized in that the
distance between the attachment points of the supports to the
ground is greater than the minimum length of the actuators.
35. Device also according to claim 32, characterized in that the
exoskeleton is connected to the platform by at least one movable
element (301), such as a gimbal suspension or a robot arm.
Description
[0001] The present invention relates to the improvement of
exoskeletons and of proxies as well as their utilization in
teleoperational applications in virtual worlds or the real
world.
[0002] Exoskeletons form a robotic suit which can be fashioned in
an anthropomorphic or non-anthropomorphic way. An anthropomorphic
mechanism is very similar in its making to the geometry and
kinematics of its wearer. Ideally is forms a kind of "second skin"
so that each point of the mechanism has a constant relative
transformation to a fixed reference point of the user body. The
exoskeleton of insects comes very close this ideal. Anthropomorphic
exoskeletons can be mounted firmly to the human body at many point
or at large areas, without significantly decreasing the range of
motion of the user or that forces and tensions between the
exoskeleton and the user are present. This allows for example the
mounting of body armor or of haptic and tactile input- and output
units respectively at the body of the user, the exoskeleton or
both. Non-anthropomorphic exoskeletons are generally only mounted
to a few points of the user body, for example at the hip and the
feet or at the back and the hands. Here the mechanism is fashioned
in a way that it follows the movements of the hands or feed and at
no time in its workspace touches, with its leg- or arm-mechanism,
the body of the user at any other than the mounting points.
However, the non-anthropomorphic mechanism as a whole can perform
very different movements than the user and can have more or less
degrees of freedom than the sum of the degrees of freedom of the
moving body parts of the user connected to the mechanism.
[0003] Non-actuated exoskeletons can be used to transfer loads
which act on the user, e.g. by heavy luggage, tools or also the
body weight of the user, onto the ground and thereby relieve the
joint and muscular system of the user. By this the endurance of the
user and also his effective strength can be increased.
[0004] Motor driven, actuated exoskeletons find application in
various areas. They can be worn as a freely moving, robotic suit
which possess an inbuilt energy supply and electronic control. They
can also be used to improve the strength and endurance of the user
while he moves untether in his environment. Applications lie in the
support of heavy physical work like ship construction, increase of
the physical power and the protection (armament) of soldiers, the
rehabilitations of sick or the utilization as walking aid for
physically impaired persons.
[0005] Force- and torque sensors at the joint of the exoskeletons,
at contact point between the user and exoskeleton or sensors for
the measurement of myoelectrical signals on the skin or implanted
in the user can be used to control the motions sequence of the
exoskeleton. Especially in the application as a "walking
wheelchair" the input of control signals can also be made via a
joystick, facial or gaze recognition or through similar manual,
acoustic or visual input means. Stationary exoskeletons are used,
among other things, for rehabilitation. They allow that the user
can be guided though an exactly predetermined motion sequence and,
if necessary, to apply forces. In this manner muscles as well as
nerves can be stimulated and the mobility of the user can be
improved with lasting effect.
[0006] Another application of stationary exoskeletons lies in the
area of the interaction with virtual worlds or the control of real
robots. Here, an exoskeleton can be used to create a teleoperative
connection between the user and the proxy (virtual avatar or real
robot). Thereby the user uses the exoskeleton to transfer direct
control commands to the proxy. Then, the limbs of the user and of
the proxy simultaneously execute almost identical motion sequences.
At the same time force feedback also can be provided so that the
user can also experience the forces which act of the side of the
proxy and the forces of the user on his exoskeleton can be applied
at the proxy. Here, anthropomorphic exoskeletons have the advantage
over non-anthropomorphic ones that really every body part of the
user can be used for the haptic interaction (for example not only a
hand but also a lower arm or upper arm) and at the same time
devices for the relaying of tactile or heat stimuli can be mounted
to the user as well as to the exoskeleton.
[0007] Especially when the legs of the user are supposed to be used
to directly control the legs of a proxy, if applicable with force
feedback, and the user in this fashion also has to or can directly
control the balance of the proxy, the user in the exoskeleton is
mounted to a motion base (DE 10 2010 023 914 A1, "Verfahren and
Vorrichtung zur Steuerung eines Statthalters"). Then, the user does
not stand on a solid floor anymore but the feet of the exoskeleton
display to the user, while walking and running, the properties of
the virtual or remote real floor while the user in the exoskeleton
is being suspended over the actual floor by the motion base. Then,
constant and time depended linear and rotatory acceleration are
displayed to the user in the exoskeleton by the motion base. As he
will generally use stereoscopic goggles or other suitable means to
perceive a realistic visual impression of the virtual or real
environment of the proxy, and these impressions are supplemented by
the corresponding haptic and if applicable tactile sensations, he
has the impression to be act in the place of the proxy in a virtual
or remote real environment. Should the user control the proxy in
such a way that it does not walk or run, but should instead climbs,
robs, craws, or walk on its hands, etc., naturally the floor is not
only displayed via the feet but also via other body parts or areas
of the exoskeleton. Notably --but not exclusively--this can be the
lower legs, knee, upper legs, hands, lower arms, upper arms, head
or the back.
[0008] In such an application the load bearing capacity of the
exoskeleton is of outstanding importance. It has to carry the
weight of the user without notably deforming or changing its joint
and actuator states significantly. Furthermore, it also has to
additionally display great dynamic forces, as they can occur during
running or jumping, precisely with smallest reaction times and
delays as well as smallest oscillations and actuator deflection.
Furthermore, it is desirable that the actuators of the exoskeleton
can give in when the forces that the user exerts on them are so
strong that the mechanism or the control are not fast or strong
enough to provide an appropriate resistance. This back-drivability
guarantees that neither the user nor the exoskeleton take harm and
that also the control over the system does not need to get lost
when overly large or quickly arising forces act. For mechanical
systems like gears, set-up gearboxes, set-down gearboxes, etc., to
be back-drivable they must possess a large mechanical degree of
efficiency, which means low internal friction and low internal
energy losses.
[0009] A large degree of efficiency of course in generally useful
as thereby the requirement on the actuators, motors, gears and
energy supply can be reduced to achieve a desired requirement like
power, force, or velocity. It also simplifies the modelling and
thus the control of robotic systems and especially of systems with
force-feedback, as the internal losses and acting forces are easier
to quantify. Especially for mobile exoskeletons, which are worn by
the user and possess a suitable energy supply and control units,
the degree of efficient also affects the operation time, the weight
and the volume of the exoskeleton and the necessary energy supply
and energy storage.
[0010] Generally, it is advantageous when the actuators of
exoskeletons use as little space as possible and make optimal use
of the available space. For mobile exoskeletons it is of interest
to carry as much payload as possible. Bigger actuations reduce the
available volume for that. Of great interest for applications for
teleoperations are especially exoskeletons which offer a maximum of
mobility (in the sense of the possible body poses) for the user and
which actuate all or the most degrees of freedoms of the body,
especially those of the hip. Also, mobile exoskeletons with which
great payloads need to be carried have similar requirements as also
here the degrees of freedoms need to be actuated which at lower
requirements still can be driven exclusively by the body strength
of the user alone. Such exoskeletons with many actuated degrees of
freedom require more space as more and larger actuators are needed.
Also, exoskeletons used for physical rehabilitation, as walking
aid, or "walking wheelchair", which do not necessarily need to bear
large forces, ideally actuate all degrees of freedom, as is allows
for greater and more natural mobility. For all these applications
it applies that a multitude of, if necessary, large actuators,
motors and gears then can reduce the range of motion of the user as
they can during extreme movement, like a lunge, a split, the
crossing of the legs, sitting or a internal or external rotation of
the foot, or the hip joint, themselves get in spacial conflict with
the other elements of the exoskeleton, the payload, operational
units, the environment or the user.
[0011] Here, a high degree of efficiency is helpful to reach the
requirements on the exoskeleton and to save space. This is
especially then difficult when gears need to be used to create the
necessary large forces. Multistage reduction gears generally are
not back-drivable, reduction gears with few stages are exposed to
large or too large forces and need to be very large and heavy.
Brushless electro motors can be extremely efficient and can possess
large powers at small volume and dimensions. But they can only
create relatively small torques. Brushless torque motors are also
very efficient but require relatively much space because of their
large diameter. They also have increased requirements on the
voltage supply to create large torques without reduction means.
[0012] Known are serial, elastic actuators (serial, elastic
actuators; "Series Elastic Actuators for legged robots" J. Pratt,
Krupp, 2004; "Stiffness Isn't Everything", G. Pratt et al, 1995;
U.S. Pat. No. 5,650,704, "ELASTIC ACTUATOR FOR PREC,ISE FORCE
CONTROL", G. Pratt, M. Williamson). They find applications in
humanoid robots and exoskeletons to directly drive joints or ropes
(if applicable in Bowden cables) which then actuate axes via
pulleys.
[0013] Actuators of this type are used as linear actuators to
drive, via leavers, hinge joints, like those of the foot joint or
the knee (M2 robot, MIT). Also known are application where the
linear actuator forms a triangle with the to be actuated joint and
where by changes of its length the angle of the joint is actuated
(RoboKnee, Yobotics). In general, the problem arises that at such a
mechanism the gear ration varies with the angle. This is why often
compromises in the construction need to be accepted, like e.g. too
large to too small gear ratios in some areas of motion need to be
tolerated to be able achieve the necessary values in other areas of
motion. This is why also too large and unnecessarily fast actuators
and motors are used. Additionally, it is difficult to cover large
angular ranges of actuation as for larger areas "dead point" can
occur where no torque can be created and the direction of rotation
for a given change of length is undetermined. Additionally, it is
not trivial to mount the actuator at the limbs of the robot or
exoskeletons as this directly influences the aggregate properties
of the system.
[0014] Especially in both of the robots M2 and M2V2 also a
mechanism was used for which a serial, elastic actuator (also
called SEA) drives a closed rope, or an equivalent setup, which is
guided over two pulleys. One acts as an idler pulley while the
other drives an axis and in this manner actuates a joint (M2:
30
http://www.ai.mit.edu/projects/labtours/LeggedRobots/LeggedRobots.ppt,
page 17; M2 http://www.jontse.com/portfolio/m2.html. FIG. 1; M2V2
http://robots.ihmc.us/humanoid-robots/). In comparison to its total
length this setup only has a small linear range of motion. For a
given pulley diameter of the driven axis this limits the available
maximum angular range (difference of maximum to minimum angular
position of the pulley, the axis, if applicable of the joint).
Furthermore, the maximum torque at the driven axis is limited, for
a given maximum angular range and thus the given pulley diameter.
Larger pulleys create, for a given force of the SEA, a larger
torque but then require larger linear positional ranges of the SEA
for a given maximal angular range. In robots and exoskeletons the
available space is limited. Because of that it is advantageous to
be able to use a largest possible fraction of the available length,
e.g. of the length of the thigh, as liner range of motion.
[0015] Different setups face this problem by not mounting the
linear actuators at the joint, but for example at the back of the
robot or exoskeleton (Walkagain Project,
https://www.youtube.com/watch?v=TcAvtglo9Jg) and by using Bowden
cables to drive the joints. Furthermore, several actuators are
being connected in parallel to exert larger forces or actuators are
being operated as antagonists to each other so that one creates
pulling and the other one pushing while the joint in actuated with
larger force together. Furthermore, systems are known where several
motors, via toothed gears or toothed belts, together drive one ball
screw of an actuator.
[0016] At a perfectly anthropomorphic exoskeleton the individual
parts undergo the same transformations as the corresponding human
body parts. For example, the knee joint can in good approximation
be described as a hinge joint. With a fixed thigh and flexion or
extension of the lower leg the lower leg then undergoes a pure
rotation around a transversal axis which intersects the head of the
femur perpendicularly to the sagittal plane. The biological axis
itself moves (translation and rotation) only slightly during
bending the lower leg. That means that for the connection of the
upper and lower leg with an exoskeletons a simple mechanism is
suitable for which the axis of is hinge joint coincides with the
axis of the knee joint, for example in the pose of the fully
stretched leg. In this case the upper part of this section of the
exoskeleton can be mounted firmly to the upper leg and the other
part firmly to the lower leg. Since the knee joint is also not a
perfect hinge joint, tensions will still occur between the
exoskeleton and body parts if the joint is moved far beyond its
initial position. This effect can be easily compensated by suitable
cushions so that the user is not suffering greater impediments or
inconveniences when he moves his knee. The knee also has a limited
range in which it can rotate around its vertical axis. This
movement is suppressed with such a mechanism but this limits the
function of the knee only to a small degree. Therefore, it is
sufficient for almost all applications to understand the knee joint
of the human as a mechanism with only one degree of freedom and to
here design an exoskeleton accordingly. Still, like in the case of
the "SERKA knee actuator", also polycentric joints can be actuated.
Especially when the knee joint of the exoskeleton is to be actuated
it is generally sufficient to only consider the main degree of
freedom (flexion and extension) as it covers the largest part the
workspace and as it provides the by far largest fraction of work
during movement.
[0017] If the same assumption is made for the ankle joint, so that
only flexion and extension of the exoskeleton are possible, this
limitation is more significant. While the ankle joint can perform
flexion and extension as a practically pure rotation around one
axis it also possesses an significant degree of freedom of
pronation and supination (as well as minor translations and
rotations of the axes). The second degree of freedom is important
to control the balance while standing and all modes of gait and to
allow that the sole of the foot, and if applicable that of a worn
shoe, independently of the tilt of the ground and of the body
stance of the user, can always be flatty placed onto a slanted
ground. Are pronation and supination suppressed, for example while
carrying of stiff shoes for the sport of downhill skiing (which
allow flexion and extension at least partially) the possibly of
walking is significant restricted. This is why exoskeletons
generally posses more than one degree of freedom for the ankle
joint or an exoskeleton or this joint is completely avoided and
only the upper leg is supported. In this case the exoskeleton ends
at the lower legs and the foot of the user and the muscles of the
lower limb have to create all the forces and movement without
support (z.B. AirLegs,
https://www.youtube.com/watch?v=U2e4tGokqeO). For actuated
exoskeletons for the angle joint generally only one dregee of
freedom of flexion and extension of the foot are actuated (z.B.
BLEEX, "On the Mechanical Design of the Berkeley Lower Extremity
Exoskeleton (BLEEX}", Adam Zoss, H. Kazerooni, Andrew Chu).
Especially for freely movable exoskeletons for the augmentation of
the performance of the user this is sufficient as here, during
locomotion, the largest forces and powers arise. This is why the
user can already be supported very much by a single actuated joint
of the foot while he controls the other degree of freedom through
his own muscle activity. The actuation of the second degrees of
freedom is hard as the actuators require space and can hamper the
mobility of the user in the exoskeleton.
[0018] The hip joint of the human is in good approximation a ball
joint. Thus, it possesses three mutually independent degrees of
freedom of rotation around the center point of the head of the
femur and no significant translational degrees of freedom. All
these degrees of freedoms are important to allow for natural
locomotion, to perform work, to maintain balance and to control the
orientation of the feet in respect to the ground. For freely moving
exoskeletons for augmentation of the performance of the user here
generally only the flexion and extension of the thigh is actuated
as this degree of freedom performs the most work. For exoskeletons
which are used as walking aid partly also only this degree of
freedom of the hip is actuated (Argo ReWalk Exoskelett, Indego
Exoskelett, NASA X1). But then a paralyzed user then additionally
needs to use crutches or alike to control the balance or to
influence the direction. For exoskeletons which are used as
"walking wheelchair" and which require no crutches at least also
the abduction and adduction are actuated (REX exoskeleton). Here
the control happens for example by means of a joystick. For
existing exoskeletons of this kind, the motion sequences are
notably slow what may be attributed to the used motors and gears
and that the user may not be exposed to too large forces so that
his body can follow the given motion sequence of the
exoskeleton.
[0019] At present the hip joint us not being actuated corresponding
its inherent degrees of freedom. Instead, non-anthropomorphic
mechanisms are being used which display significantly different
transformation properties than those of the three independent
rotary degrees of freedom the hip joint. So, for example, only two
axes are being used of which one is generally parallel to the
transversal axis and which is designed in a way that it runs at
least in the proximity or also through the center point of the head
of the femur (BLEEX). Since most of the work is done along this
axis during walking and running, flexion and extension, this is
also the axis that is preferably actuated in mobile, actuated
exoskeletons.
[0020] The other preferred axis lies parallel to the sagittal axis.
Here it is not necessarily observed that it is actually running
through the center point of the head of the femur (POWERLOADER
PLL-01, https://www.youtube.com/watch?v=vdhUpR-dzgk; FORTIS by
Lockheed Martin
http://robrady.com/design-project/lockheed-martin-fortis-human-poweedexos-
keleton; "Design of a Walking Assistance Lower Limb Exoskeleton for
Paraplegic Patients and Hardware Validation Using Cop", Jung-Hoon
Kim et al., http://cdn.intechopen.com/pdfs-wm/42836.pdf), while
this may not be an ideal choice for an anthropomorphic mechanism.
As often a third hip axis is forgone (XOS 2 of Ratheon Sarcos), and
instead the "thigh" or "lower leg" of the exoskeleton are design in
a way that they can also allow a rotation around the vertical axis
and thus allow that the foot can rotate correspondingly, in general
a non-anthropomorphic mechanism is present. Because of that, during
the motion of the leg, it comes to significant displacements
between the body of the user and main parts of the exoskeleton.
These displacement are being allowed by corresponding compliant
mechanisms, additional non actuated joints, cushions, etc., at the
mounting location between exoskeleton and user ("Exoskeleton for
Walking Assistance",Qingcong Wu et al). Therefore, it is not
possible to cover the whole workspace of a human with such
mechanisms and they focus on main motions like walking, running and
sitting. Here only a small part of the possible workspace of a
human is required and therefore the possible workspace of
individual joints is only being used to a limited extend.
[0021] It is the purpose of the present invention to improve
exoskeletons and proxies, such as robots and virtual avatars, as
well as associated control units in such a way that they can be
used to make extensive movements, give a realistic impression and
can also be operated quickly and effectively.
[0022] This problem is solved by the device according to
independent claim 1. By the sub claims further improvements are
claimed according to the invention.
[0023] The device described in claim 1 concerns in particular
exoskeletons as well as proxies, like robots or virtual avatars, as
well as motion simulators and other otherwise suitable virtual or
real machines. With the devices of the mentioned kind various
motions and motion sequences are to be recorded and/or to be
executed. This is why we note that the present invention is mainly
described on the basis of an exoskeleton. However, it is by no
means limited to this but includes all the devices mentioned.
[0024] The device according to claim 1 comprises, beside other
means, four elements whereby neighboring of these elements are each
mounted in a rotatable fashion about corresponding axes. For this,
between neighboring elements, rotary joints are provided which can
be fashioned in various ways like for example as a shaft or the
like. Hereby it is material that the mentioned three axes in
general run through a common point. Preferentially this point lies
in the center of the respective--i.e. the right or the left--hip
joint.
[0025] The first rotary axis and the second rotary axis form a
first angle .phi..sub.1 and the second rotatory axis and the third
rotary axis form a second angle .phi.2.
[0026] This invention has the advantage that is allows to design
exoskeletons with complex degrees of freedom, like the hip joint,
as anthropomorphic as possible and to permit that all degrees of
freedom can be actuated in the whole range of motion of the user
with greatest forces, increased efficiency, low space requirements
and weight, high actuation speeds, increased power, with back
drivability, low backlash and short reaction times.
[0027] By this, in particular, it becomes possible that an
exoskeleton for the legs is able to carry the body weight of the
user while he wears it like a robotic suit and the exoskeleton
itself can be carried and moved by a motion base. Now, at the same
time, the mechanism can now appear so stiff that is can display to
the user a hart floor and fast movements realistically without that
the use in the exoskeleton actually would be standing on a hard
floor. In the same way the performance of mobile exoskeletons and
humanoid robots is increased as also degrees of freedoms can be
actuated which so for could not be actuated or which were not
actuated because of various considerations. The requirements on the
energy supply are reduced and/or the range and time of operation is
increased. For stationary exoskeletons for physical rehabilitation
in this way the trainable range of motion can be increased and the
efficacy of a treatment can be increased or other treatments than
performed so far can be facilitated. By the new geometry of the
exoskeletal hip joint and also by its new mode of driving, an
improved flexibility of actuated exoskeletons of the legs in
accomplished. By the possibility of localizing the motors in the
proximity of the joints means of force- and power-transmission are
saved and the mechanism is simplified, compared to e.g. hydraulic-,
cable- or Bowden cable transmission. The hip mechanism can be
designed to be comparatively space-saving and does not limit the
available payload of mobile exoskeletons. The largely
anthropomorphic behavior of the exoskeleton allows stable mounting
to the user over large parts of its body and thus simplifies the
generation of haptic feedback and the utilization of tactile in-
and putput units. Likewise, the utilization of a housing, an armor,
or tactile and thermal in- and output units is facilitated, even
for simultaneous actuation of all joints, which can surround the
body of the user as well as the exoskeleton or can be part of the
exoskeleton.
[0028] The first elements, which is also called exo back plate or
(exo-) hip plate, preferably is a plate-like element. By it, for
the normal operation, a user is mounted firmly relative to its hip
bone. While parts of the exo back plate or the exo hip plate can be
designed in an angled or arched fashion it possesses a principal
plane. For one implementation of the device according to the
invention the first of the named axes is perpendicular or generally
perpendicular on the named principal plane and therefore is
generally parallel to the sagittal plane of the user.
[0029] It is also possible that the first axis is not perpendicular
to the principal plane of the first element (exo back plate) but
deviating thereof, while it is in general still running through the
beforementioned common point. This deviation can be described as
follows. In the standard pose the principal plane of the exo back
plate runs from top to bottom (or the other way around) vertical or
in general vertical. Starting from here a vertical axis can be
define which on one site is in general vertical and parallel to
this principle pale and on the other side runs through the common
point. For this realization of the device according to the
invention the first axis is rotated by a third angle .alpha. around
the named vertical axis while this angle consequentially lies
generally in the horizontal plain. Thereby a greater rotation of
the feet towards inside or outside (with a negative angle .alpha.)
is made possible.
[0030] It is furthermore possible that the first axis is rotated by
a fourth angle .beta. around a horizontal axis. This rotary axis in
general runs perpendicular to the mentioned vertical axis, parallel
to the principal plane of the exo back plate and also through the
common point. The associated advantages of this realization are
mentioned in the context of the description of preferred embodiment
examples.
[0031] For one preferred embodiment of the invention the first
angle (pi has a value which in in the range of 25-45 degrees. A
value of about 35 degrees has proved particularly successful.
[0032] It has also been proven that the second angle .phi..sub.2
has a value in the range of 60-80 degrees. A value of about 70
degrees has proved particularly successful.
[0033] Devices with a combination of the angle .phi..sub.1 and
.phi..sub.2 in the ranges as described in the previous two
paragraphs give exoskeletons which posses a large workspace which
allow for generally large stride lengths, a large extra rotation of
the foot and generally a large mobility. These exoskeletons are
especially suited for the control of humanoid robots and virtual
avatars by teleoperation.
[0034] Should special attention be given to easy sitting in the
real word exoskeletons are suited for which the sum of the first
angle (.phi..sub.1) and the second angle (.phi..sub.2) are between
85-120 degrees and the thirst angle (.phi..sub.1) has a value in
the range of 15-45 degrees.
[0035] For the third angle .alpha. and/or for the fourth angle
.beta. values between 10 and 30 degrees and preferably about 20
degrees have proved to be particularly successful.
[0036] Further claims concern a fifth element that in relation to
an exoskeleton, a proxy or alike can also be called a foot. This
foot is characterized thereby that its standing surface, on which
the user stands (also called the sole) has a certain profile. This
profile is characterized by two circular segments with different
radii of circles. Preferably these have their centers close to the
ankle joint of the user. It is also preferred that these circles
are parallel to the frontal plane of the user. Furthermore, it is
preferred that it allows agile motions while it only possess a
single axis. It be mentioned that the term circle, here and also in
the context of the description of preferred embodiments, also
includes circle-like geometries, like ellipses or similar. This
makes it possible for it to allow agile movements even though it
has only one axis. It should be noted that the term circle here and
also in connection with the description of preferred execution
examples also includes circle-like geometries, as well as ellipses
or the like.
[0037] The foot as according to the invention can be used together
with the previously described device according to the invention or
independently thereof. This also applies to all the execution
examples described below as part of the description of preferred
execution examples.
[0038] Exoskeletons or proxies, like humanoid robots require two
degrees of freedom of the foot to get close to the mobility of the
human. The actuation of both degrees of freedom requires suitable
means which demand space and weight. The stronger and more powerful
the exoskeleton is to be, the heavier these actuators generally
become and require more space.
[0039] By the choice of special sole shape for the feet of mobile
exoskeletons the requirements on the actuation of the joint of the
exoskeleton are reduced and only one axis is actuated, whereby
other movement are suppressed and yet a large mobility of the user
with exoskeleton is guaranteed. As now no degrees of freedom of the
foot are used to directly drive the foot of the exoskeleton by
human force the capacity of the user in the exoskeleton is
increased and greater forces and power can be transmitted without
the user being at risk to be harmed by too large forces or not be
able to provide the necessary forces and therefore lose the control
over the motion sequence.
[0040] Further claims concern the area of gravity compensation. As
in tele operative applications the exoskeleton of the legs, which
is mounted at a hip or back element to a motion simulator, must be
able to carry the weight of the user. When standing, for example,
he then has the feeling that his entire body weight is acting on
the soles of his feet.
[0041] However, it is desirable that the user can also get the
impression that his body weight is reduced. This would be the case,
for example, if he were to control a real humanoid robot which
would operate in an environment with reduced gravity, such as free
fall, weightlessness, a stable orbit around a planet, in
accelerated inertial systems or under water, i.e. under the
influence of buoyancy.
[0042] Furthermore, such corresponding situations of reduced
gravity appear in virtual worlds and a user may want to control an
avatar therein correspondingly. In extreme cases, the user should
be able to experience weightlessness, so that he can control the
floating proxy without exerting force on his legs. Furthermore, it
may be provided that the user, with small own body forces, can
cause disproportionate forces with its proxy (real robot or virtual
avatar). During this force amplification the user in the
exoskeleton should be able too feel in a way as if he didn't have
to carry his own body weight anymore. Additionally it is also
desirable that the user can experience sustained, larger forces
than those of his body weight. So can it be necessary that these
larger forces act for a longer time, e.g. for conveying of
increased gravity, e.g. fully on his soles of the feet.
[0043] However, the user is usually actually in the gravity field
of the earth, and he must be prevented from actually changing his
position by the forces of the exo legs.
[0044] Teleoperation methods can in general also scale forces and
torques. To reduce the requirement on the exoskeleton it can be
desirable that always reduced forces, especially on the legs, are
conveyed to the user, and that the exoskeleton is not required to
be able to carry the whole weight of the user. This allows the
utilization of lighter, less tiff, weaker and smaller exoskeletons
and faster movements.
[0045] So far, the total or partial reduction of weight was
accomplished by submersing the user in the exoskeleton in a liquid.
Alternatively, the user weirs a liquid-filled suit with which he is
mounted to the exoskeleton or which is part of the exoskeleton.
[0046] The aim of this embodiment according to the invention is
therefore to enable the user in the exoskeleton to have the
impression of completely or partially lifted weight without having
to be in a liquid and/or to lower the requirements for
exoskeletons. A further objective is to allow for increased,
sustained forces on the user.
[0047] This is accomplished by suitable means like belts (like six-
or five-point belts, climbing harness, etc.), straps, shells or
harnesses that firmly connect the torso, the hip and/or the this of
the user with the hip plate and/or the back plate of the
exoskeleton without limiting the mobility of his legs considerably.
Especially suited for that are belts or shells which engage between
the legs and high up around the hip. (Alternatively, the weight of
the user can also be carried at the thighs, while the conveyed
impression suffers by that.) Preferably this carrying means is
construed in a way that it can carry the whole weight of the user
in every arbitrary load bearing direction without the user
considerably shifting in respect to the hip plate and/or the back
plate. The carrying mechanism in principle can be designed as for
the Exobionics or Indego exoskeletons.
[0048] Then a Standing User in the Exoskeleton, which is Mounted to
the Motion Base, can e.g. retract the legs and lift both from the
ground while his torso, held by the exoskeleton and the carrying
mechanism, maintains position. Conversely it then is also possible
that the user can completely extend his legs and occupy a position
which corresponds to standing but he nevertheless does not need to
carry his body weight with his legs and it also does not or only in
a very limited fashion act on the soles of his feet.
[0049] Optionally it is allowed for that the sole of the foot of
the exoskeleton can be translated and actuated in the direction of
its normal. By this it becomes possible to adapt the length of the
exo legs exactly to the effective length of the user legs and to
correct for possibly occurring small errors or changes in the
position of the user relative to the hip plate and/or back plate.
It is advantageous if this actuation can happen quickly and forces
and torques on the plate or distances to the foot can be measured
and controlled. It is important to distribute the weight of the
user as evenly as possible, with small pressure and large contact
area, on his torso (or alternatively on his thighs). In this way it
is avoided that they become too apparent and the impression of
(partial) weightlessness is improved.
[0050] In general, it is important that the weight of the user can
act in every direction and is absorbed fully by the carrying
apparatus. This way the user can be held e.g. heads down and yet
maintain a fixed position in respect to the hip plate and/or back
plate. Yet, depending on the application the carrying apparatus can
be designed in a way that it only acts in the relevant
directions.
[0051] It is possible to combine this new way of reducing of
gravity with previous methods utilizing buoyancy in liquids.
[0052] If the carrying apparatus is designed in a way that the user
cannot be pushed upwards out of the hip plate or back plate
sustained forces can also act on the feet of the user which exceed
his body weight. Thereby an increased gravity can be simulated.
[0053] The carrying apparatus can itself also be designed in a way
that it can be relaxed or moved and thereby the degree of relief
can be changed. For that the carrying apparatus, preferably on its
mounting points, possesses control members, like for example
adjustable spring elements (also air springs or alike) and/or
suitable scale elements.
[0054] The device according to the invention for gravity
compensation can be used together with the previously described
devices according to the invention or independently thereof. This
also holds for all embodiment that are explained further below in
the context of the description of preferred embodiments.
[0055] Further claims concern a device with a motor which during
operation translatorically moves, via a spindle, a means with
threads. This is connected to a rotating element, such as a chain
or the like, which then rotatorily moves a shaft. This drive device
is particularly suitable for the devices according to the invention
according to the other claims, but is not limited in any case to
such use.
[0056] The drive device mentioned, which is also called actuator in
the following, has the following characteristics and
advantages.
[0057] The requirements for power density, weight, torque,
mechanical hysteresis, stiffness, speed, efficiency and positioning
accuracy for humanoid exoskeletons are enormous when the goal is to
noticeably increase the wearer's performance in mobile
exoskeletons, to increase his strength, and especially when a
stationary exoskeleton is used as a tele-operation unit for the
legs. In the latter case, torques of easily well over 100 Nm occur
at almost all joints of the leg even during simple movements. These
torques act partly on the actuators, in their driving directions,
but also orthogonally thereto, in the latter case loading the
bearings and load-bearing structures. When running or jumping,
these torques are even higher by a multiple and the latency times
for stable control are also reduced, making fast and precise
controllability of the actuators at high performance even more
important. The back drivability of the actuators is also important
here, since forces can occur briefly in the extreme range, which
can exceed the capabilities of the actuators. The harder the remote
real or simulated environment, the less elastic the actuators and
other structure of the exoskeleton may be. This is especially true
if the poses of proxies (virtual avatar or real robot) should
always differ only slightly.
[0058] Strong humanoid robots have similar requirements, which
increase the faster they are supposed to move, and especially when
they are used as slave units for teleoperations.
[0059] Also applications using serial elastic actuators (SEA), such
as various mobile exoskeletons and humanoid robots, require high
actuation forces and large rotation angles of joints. Here the
actuators are designed "soft" and between end effector and motor
there is at least one spring element (torsion spring, leaf spring,
coil tension spring, coil compression spring, etc.), which allows
to absorb fast shocks and can be tensioned by the motor in such a
way that a desired driving force is achieved.
[0060] The drive device according to the invention concerns a new
actuator type for exoskeletons, robots or the like. Motor and
spindle are connected via suitable bearings or clamps to a base
(base plate, chassis, frame or housing; one part or more) in such a
way that they cannot be displaced against each other in the event
of external forces and motor and spindle can rotate freely around
their driving axes. The motor is mounted in such a way, directly or
indirectly, that it can carry out work on the spindle. The base is
connected to a first element of the exoskeleton (e.g. thigh) or
forms a unit with it. The spindle drives a suitable ball-bearing
mounted nut (also called nut) during its rotation, which is
connected to the base in such a way that it cannot rotate around
its longitudinal axis when the ball screw is rotated. This mounting
of the nut can be achieved by linear rails, linear bearings, roller
bearings with rail guide, etc. Preferred is the guidance by a
linear carriage/linear slide with recirculating ball bearing and
"right-angled" guide rail. This allows only one degree of freedom
and allows the absorption of torques along all axes. When the ball
screw is rotated by the motor, the nut and the carriage attached to
it then perform a linear movement. This is now used to connect a
flexible element (there) running parallel to the spindle, such as
chain, belt, belt, rope, etc., to the spindle. (hereinafter
referred to simply as "chain"). The chain is attached directly or
indirectly to the nut or carriage by suitable means. Carriage, nut
and fastener can form one unit. The chain is preferably designed to
be open in such a way that it is attached directly or indirectly to
both ends of the nut, or closed in such a way that it is attached
to the nut without itself having an end or a beginning. If a rope
is used instead of a chain, it is preferably also anchored to the
driven wheel and can also be guided more than once completely
around the drive wheel to avoid slippage. Then also e.g. two ropes,
one for each drive direction, can be used. The chain drives a drive
wheel, which in turn is rigidly connected to a drive shaft. The
chain and the drive wheel are connected to each other, like chain
and sprocket, so that no slippage occurs between these parts even
under high forces. The drive axle is mounted so that it can rotate
freely around its longitudinal axis, but withstands all other
forces and cannot move relative to the base or bearing. The chain
is additionally at least guided around one diverting element--i.e.
a suitable diverting device, such as a sprocket with bearings,
sliding bearings, circulating rollers, etc.--and from there back to
the chain wheel of the drive axle, so that the chain follows a
closed path. In addition, it should be mentioned that the chain
wheel and the drive axle can also be designed as a single part.
[0061] The free-running element (diverter wheel) is mounted to the
base, preferably by means of a ball-bearing-mounted axle, so that
the chain is always under tension, if necessary with the assistance
of one or more further tensioning elements, and can always move
freely and with little play along its running path when driven by
the ball screw or the drive axle. The drive axle or the driven
sprockets/rope pulleys etc. are designed in such a way that
another, second element of the exoskeleton (e.g. lower leg) is
rigidly attached to them. As a result of the rotation of the drive
axle or the driven chain wheels etc., the angle between the first
element (e.g. thigh) and the second element (e.g. lower leg) is
changed.
[0062] In order to transmit maximum power and torque at high
efficiency it is necessary to load the ball bearing nut on the
recirculating ball screw mainly axially, i.e. to minimize the
transverse torque on the nut. This is possible when using a single
chain by guiding it as close as possible to the ball screw and
parallel to it. Although this does not achieve a perfect axial
load, acceptable losses can still be achieved. However, the
bearings required for the ball screw increase the minimum chain
spacing for short ball screws if the spindle is approximately as
long or shorter than the straight chain section. However, if the
spindle is significantly longer than the length of the chain
arrangement, there is no possibility that the spindle bearings will
collide with the chain or sprockets. Then a single chain can be
guided very closely to the ball screw, thus keeping the torque on
the nut low.
[0063] However, in order to achieve a perfect axial load on the nut
and the rotating spindle, the load must be applied evenly on
different sides of the nut. The preferred arrangement (FIG. 27-31)
therefore has two chain wheels of the same diameter on the drive
shaft, which are also guided around two diverting devices. The ball
screw and the chains attached to it then lie, in a part of the
travel range of the nut, in a common plane. The nut is guided
between the chains and is connected directly or indirectly to the
chains, as with a connecting block (118) or on the linear bearings
(120).
[0064] It is not always desirable to allow the load to act axially
on the nut, as the necessary components require additional space on
several sides of the nut. It is possible that the load acts mainly
unilaterally on the nut if it is prevented that the nut can rotate
transversely under the effect of transverse torque to the ball
screw, i.e. the axis of the nut and the spindle are no longer
parallel to each other and/or the spindle is bent. For this
purpose, the nut can be connected to a suitable linear guide, which
preferably absorbs all transverse torques and, if necessary, has
them act on the base or other components. The chain is then driven
unilaterally by the nut, the linear carriage, a connecting block, a
spring element, etc. If a spring element is used with the chain
drive, it is preferably loaded parallel and coaxial to the chain.
Depending on the actuated joint and application, the torques on a
linear guide can still be extremely high and exceed the load
capacity of individual, small linear carriages/bearings. This is
especially true when alternating ball sizes or ball chains are used
to ensure smooth running of the bearings. Therefore, it is
advantageous to choose bearings, which have to absorb transversal
torques, as long as possible, to use several bearings in succession
and to suitably connect with each other the nut and the chain,
and/or to allow several linear guides to run parallel in order to
absorb the torques together. In the preferred design example, with
two chains, however, this is not necessary, as only minimal
transverse torques and only low axial torques act on the linear
guide here. For many applications it is also possible to use a very
simple linear guide which has the main task of preventing the nut
from rotating around its axis. This can be done e.g. by simple
linear guided round ball bearings which are directly or indirectly
connected to the nut. This is especially true when the transverse
torque on the nut is minimized by the use of chains on both sides.
However, such a simple linear guide can also be achieved with only
one side of the chain if a large diameter ball screw and/or an
extra long nut, or several nuts in succession, is used. Then the
transversal torque is mainly carried by the ball screw, not by the
linear guide, without dramatically reducing its efficiency.
[0065] It is preferable that each linear guide is not free but
supported. This means that it is connected not only at its ends to
the base, frame, etc., but over its entire length or large parts of
its length. In this way, the rigidity of the base, etc. is also
used to absorb torques and free the nut from them.
[0066] Chains, especially link chains, possess highest efficiencies
at high powers and forces and require little space. However, link
chains generally have the characteristic that they never run
perfectly "round", since the effective diameter of the sprocket
changes slightly during the process of engaging and disengaging a
chain link in the sprocket "chordal action". This "polygon effect"
is smaller the larger a sprocket and the smaller the individual
links are. Silent chains are designed in such a way that the
effective diameter remains almost constant and the polygon effect
is very low. With "SmartChains" (SmartChain B.V., Zoetermeer,
Netherlands) the polygon effect is almost perfectly suppressed. The
use of soft plastic sprockets or radially flexible sprockets with a
spring design of the sprocket under the teeth can reduce the
polygon effect. With ropes or belts, a polygon effect does not or
hardly occur.
[0067] If several chains are used, it can be advantageous to mount
the sprockets, which share a common axis, rotated relative to each
other, so that there is a phase difference between their teeth. If,
for example, two chains are used, one on each side of the ball
screw, the phase difference can be half the sprocket pitch
(180.degree.). If two sprockets and chains are used on each side,
two wheels on the same side may have a phase difference of
90.degree. to each other. The two wheels on the other side then
preferably have a phase difference of 180.degree. to each of the
wheels on the first side. If each wheel on one side is opposed by a
corresponding wheel on the other side with 180.degree. phase
difference, the total axial load on the nut is averaged in the best
possible time. The transversal torque on the nut, however, still
has clear maxima and minima. This influence on the torque is
minimized by using several pairs of gears, with 2 sprockets of the
same phase to each other on the same axis, but with phase
differences to the other pairs of sprockets. Examples for possible
sprocket phases for systems with one-sided chain arrangements are
given in the following Table 1, whereby the mentioned phases are
only exemplary, because a multitude of further phase differences
are possible. This is a table of different phases with 1, 2 and 3
chains which act on one side of the nut and/or linear guide.
Therefore, the polygon effect is reduced. However, transverse
torques act on the nut and/or the linear guide. Any of these phase
configurations can be practicable for low forces, strong nut and/or
strong linear guide. The chain or chains can be in the same plane
as the ball screw (left or right thereof), but can also run above
or below the ball screw. Thus chains can be omitted or phases can
deviate without substantial losses need to be accepted. By analogy,
Table 1 can also be used for 4 or more chains. The phases in the
table are given as multiples of the pitch.
TABLE-US-00001 TABLE 1 chains Number of Chain denomination chains 3
2 1 1 0 2 0 1/2 2 1/2 0 3 2/3 0 1/2 3 0 1/3 0 3 1/3 2/3 1/3 3 1/3 0
2/3 3 0 2/3 0 3 2/3 1/3 2/3
[0068] Individual chains or special multi-strand chains with links
offset from each other (e.g. U.S. Pat. No. 6,190,278 B1) can be
used. The latter have the advantage of requiring less space and
enabling a more uniform run.
[0069] In order to further reduce the influence of the polygon
effect, the shaft distance between drive wheel and deflection wheel
is preferably selected so that the free length of the driven chain
section is always exactly a multiple of the chain pitch.
[0070] It is possible to further reduce transverse torques on the
nut by running a chain on both sides of the nut at the same
distance from the axis of the ball screw and with a common phase.
Other pairs of chains of this type, but with an even phase
difference to the other pairs, can be used to make the run more
even, as the driving force is smoothed. In the following table 2
corresponding examples for two-sided chain arrangements are given.
It contains all permutations of the phases for 2, 4 and 6 chains
for which the transverse torque, the sum of the individual
transverse torques of all chains, is minimized to the nut and/or
linear guide. The more chains are used, the more dispensable
becomes each individual chain and the exact choice of phases. Thus
chains can be omitted or phases can deviate without substantial
losses need to be endured. Table 2 can also be used analogously for
4 or more chains on each side.
TABLE-US-00002 TABLE 2 Chains Left Right Chain denomination: Number
of chains 3L 2L 1L 1R 2R 3R 2 0 0 4 1/2 0 0 1/2 4 0 1/2 1/2 0 6 2/3
1/3 0 0 1/3 2/3 6 0 2/3 1/3 1/3 2/3 0 6 1/3 0 2/3 2/3 0 1/3 6 1/3
2/3 0 0 2/3 1/3 6 0 1/3 2/3 2/3 1/3 0 6 2/3 0 1/3 1/3 0 2/3
[0071] Although less phases are used by this mechanism with a given
number of chains and sprockets, since two chains always have the
same phase, a more uniform run can be achieved by reducing the
transverse torque to the nut. The use of "phased chains" is
preferable to the use of individual chains. They are preferably
used in pairs for pairs of sprockets with a phase difference of
half the link spacing. For this purpose, the sprockets must be
arranged in pairs on the axles. Silent chains have advantages over
roller chains. A phased chain then replaces several of the
previously mentioned single chains.
[0072] The influence of transverse chain torques on the nut can be
reduced by connecting the nut directly or indirectly to the
carriage of a linear guide so that transverse torques are absorbed
by this guide. The chain or chains can also be connected to the
carriage of the linear guide itself. The nut can also be designed
in such a way that it takes over the characteristics of the trolley
and itself has rollers, bearings, wheels etc. which in turn run on
a liner rail which absorbs the transverse torques. Each of these
rails is generally also suitable for absorbing longitudinal torques
of the nut, which is a prerequisite for the nut moving
hysteresis-free along the ball screw during spindle rotation and
not remaining in place.
[0073] In order to work as hysteresis-free as possible, the chains
or other flexible elements must be pre-tensioned. For this purpose,
the axle of the diverter sprockets is preferably mounted in such a
way that it can be shifted along the direction of the recirculating
ball screw. Alternatively, other free-running idler wheels can also
be used, the position of which can be adjusted so that the preload
can be regulated. Chains have the advantage, especially compared to
ropes, that they require only little pre-tension to work with low
hysteresis.
[0074] For achieving a large transmission ratio (small motor
torques should become large torques of the driven axle), a large
drive wheel diameter and a small pitch of the ball screw are
required. For a given rotation angle of the driven axis to be
covered, this leads to larger necessary distances over which the
chain must be guided in a straight line. For large rotation angles
and large transmission ratios, this leads to large necessary
lengths of the ball screws and thus to a large actuator length.
This can be particularly problematic when driving the third axis 95
of the exoskeleton (FIG. 1-26), which controls the flexion and
extension of the thigh, as large torques and large rotation angles
are required here.
[0075] The reduction ratio from ball screw to driven axis is
(Pitch of the ball screw)/(Circumference of driven
sprocket)=pitch/(2 pi r).
[0076] Thus, with a 150 mm diameter sprocket and a 5 mm pitch ball
screw, a reduction ratio of approximately 1:94 can be achieved. For
practically all possible pitches of the ball screw a simple back
drivability of the mechanism is given.
[0077] Instead of a ball screw and a ball nut, other means such as
an ACME screw etc. can be used. In this case, however, the back
driveability can be lost and the efficiency can decrease.
Additionally, a low reduction gear can be connected between motor
and spindle in order to improve the total reduction ratio without
loss of back drivability in order to achieve higher torques on the
driven axle. It is also possible not to use the driven axle
directly to drive a robot joint, but to use it to drive another
sprocket, which drives a chain gear, which ultimately actuates a
joint. Similar can be achieved with belts, ropes, or gear wheels
etc.
[0078] Also, the ball screw can be driven at both ends by two
motors to increase power, acceleration and torque. The motors can
also be connected in series on one side of the spindle by
connecting their axes longitudinally. This is equivalent to a
longer motor. The recirculating ball screw can also be designed so
that it is driven from the inside by a motor, or the outside of a
motor holds the guides of a ball screw. This has the advantage that
the entire length of the spindle can be used as a motor and the
overall structure is shorter.
[0079] The motors, or the motor, do not necessarily have to be
mounted coaxially to the ball screw. Thus it is possible to use,
between motor and ball screw, a Cardan shaft, a bevel gear, a
hypoid gear, a toothed belt drive, or similar. In this way, the
position of the motor in the housing can be influenced and the
housing size can be reduced. The reduction ratio can also be
further influenced in this way. In general, the torques and forces
occurring directly at the motor are still the lowest, so that
relatively simple and cost-effective means of reduction, power
transmission and axis direction change are suitable here.
[0080] In general, it is preferable to fix the recirculating ball
screw at its two ends with fixed bearings on the base. This
increases the axial load capacity (buckling load) by a factor of 2
compared to a fixed bearing on one side and an "axially free" or
"supported" bearing on the opposite side. This significantly
increases maximum accelerations and speeds and resonance
frequencies. Then there is no difference between operation in
pulling direction or pushing direction. Also, forces are
transferred more evenly to the base.
[0081] The drive device (actuator) according to the invention can
be used together with the devices according to the invention
described above or independently of them. This also applies to all
the embodiments discussed below in the description of preferred
embodiments.
[0082] Further claims relate to a motion simulator, in particular
its rotation unit. They are preferably made up of at least three
rotation elements, whereby neighbouring elements are rotatably
connected to each other. The first rotary element is rotatably
mounted on other devices, such as the means of a translation unit.
At last, like e.g. third rotation-element, an exoskeleton or
similar is mounted rotatably. This device according to the
invention is based on the following findings.
[0083] Exoskeletons for teleoperation, i.e. to control proxies in a
virtual (avatars) or real environment (humanoid robots), use motion
simulators to exert static or temporally variable body
accelerations on the user. For this purpose gimbal suspensions are
also used.
[0084] In particular, this requires systems with four independent
axes to avoid the effect of "gimbal lock". This condition occurs
when degrees of freedom are lost at certain positions of the axes
relative to each other, especially in the case of axes parallel to
each other or when more than two axes lie in a common plane. In the
proximity of these states, the necessary positioning speeds of the
axes can become very high or arbitrarily high in order to change
from one orientation of the user, even slowly, to another.
[0085] With gimbal suspensions with only three axes, this effect
can make it technically and practically impossible for the user,
controlled by the motion simulator's electronics, to take up
certain areas of orientation in space in order to experience a
suitable spatial position or acceleration impression.
[0086] If four axes are used, they can be suitably controlled so
that three degrees of freedom are always available and no extreme
speeds or accelerations are required. Such a system generally
consists of 3 elements which each have 2 axes and together 4
independent axes. Such a system is generally larger and heavier
than one with only 3 axes. This is especially true when each
element circumscribes a full circle or a semicircle. These elements
are then also particularly inert and resist rotatory and
translatory accelerations. The same applies to elliptical or other
shapes with large angular distances. In addition, errors in the
positioning angles add up especially when the axes of each element
are at large angles to each other. These angles are usually
selected as 90.degree.. It is especially important when the
innermost element should resemble a full or semicircle that it is
large enough in diameter that the user can never collide with
it.
[0087] The motion simulator according to the invention contains a
special gimbal suspension. The sum of the element angles (angles of
the two axes of an element to each other) must be greater than
180.degree. to avoid a gimbal lock and to allow the user in the
exoskeleton to take all possible spatial orientations.
[0088] The motion simulator according to the invention may be used
together with the devices according to the invention described
above or independently of them. This also applies to all the
embodiments discussed below in the description of preferred
embodiments.
[0089] Further requirements concern a motion platform, in
particular a special design of a hexapod (here also called Stewart
platform). According to the invention, a movable working platform
is provided which can be moved by actuators. On the inside of this
working platform, an exoskeleton is mounted, preferably in such a
way that the corresponding user is centered between the mounting
points of the actuators on the frame.
[0090] For a further development of the platform according to the
invention, it is intended that supports are provided between the
actuators and the working platform. These should be long in order
to increase or maximize the working space of the motion simulator.
Furthermore, this is based on the following findings.
[0091] As motion platforms for exoskeletons in teleoperations
(virtual or real governor) Stewart platforms are also suitable.
These generally have six linear actuators, or similar means, which
on one side are fixed to the floor or other base and at the other
side are fixed to a work platform or working plane. By suitable,
coordinated actuation of the linear actuators, the working platform
can be freely actuated and accelerated in six degrees of freedom in
space. In this way, arbitrary linear or rotational positions,
velocities and/or accelerations of the platform can be generated.
If the user in the exoskeleton is now attached to a Stewart
platform, any body acceleration of the proxy can be transferred to
the user, also by means of a motion cueing process.
[0092] Stewart platforms do not allow every spatial orientation.
However, they have the potential to allow almost any or every gait.
To achieve this, however, the technology must be adapted to the
requirements of teleoperation with exoskeletons in order to fully
exploit its potential. Conventional Stewart platforms require a lot
of space and are high. Applications in tele-operation with
exoskeletons primarily require rotations around points inside or
near the user's body. However, if the user should be mounted on the
working platform of a Stewart platform, such rotations are
possible, but the working range of the Stewart platform is then
small and large travel distances and speeds are required. It is
advantageous if the centers of rotation are located approximately
in the center of gravity between the mounting points of the linear
actuators on the moving working platform.
[0093] The motion platform according to the invention may be used
together with the devices according to the invention described
above or independently of them. This also applies to all the
embodiments as explained below in the description of preferred
embodiments.
[0094] Further details and advantages of the present invention are
explained in the following by means of preferred embodiments with
corresponding figures. These show:
[0095] FIG. 1 a perspective representation of an exoskeleton
1000
[0096] FIG. 2 top view of the exoskeleton 1000
[0097] FIGS. 3-5 illustration of different angles for exoskeleton
1000
[0098] FIG. 6-11 different representations of exoskeleton 1001
[0099] FIGS. 12-17 different representations of exoskeleton
1002
[0100] FIGS. 18-23 different representations of exoskeleton
1003
[0101] FIGS. 24-26 different representations of the divided second
element (82a-c)
[0102] FIGS. 27-31 different representations of the actuator
2001
[0103] FIGS. 27-31 different representations of the actuator
2001
[0104] FIG. 32 side view of actuator 2002
[0105] FIGS. 33-37 different representations of the actuator
2003
[0106] FIGS. 38-41 different representations of the actuator
2004
[0107] FIG. 42, 43 different representations of the actuator
2005
[0108] FIGS. 44-46 different representations of the actuator
2006
[0109] FIGS. 47-49 different representations of the actuator
2007
[0110] FIGS. 50-52 different representations of the actuator
2008
[0111] FIGS. 53-54 different representations of the actuator
2009
[0112] FIGS. 55-58 different representations of the motion
simulator 3000
[0113] FIG. 59 the exoskeleton 203 with back mount
[0114] FIGS. 60-63 different representations of the foot 9000
[0115] FIG. 64, 65 different representations of the Stewart
platform 4000
[0116] FIG. 1 shows a perspective representation of a preferred
execution example for an exoskeleton 1000. This contains a first
element 80a, also called Exo back plate, which is fixed in normal
operation relative to the hip bone of a user. This exo back plate
80a comprises in the lower area on each side an axle mounting
region 80b, which are inclined inwards and are also called mounting
elements 80b. On each of these mounting elements 80b a second
element 82 is rotatably mounted by means of a shaft 81. By means of
a further shaft 83 (see FIG. 2) a third element 84, consisting of
the two legs 84a, 84b, is rotatably connected to the second element
82. Since the two elements 82, 84 take over the essential functions
of a hip joint, they are also called the first exo-hip joint 82 and
the second hip joint 84 respectively. Via a further shaft 85, a
fourth element 86 is rotatably connected to the second exo hip
joint 84, which is also known as the exo thigh. Underneath thereof
is a fifth element 88, also known as the exo lower leg, which is
rotatably connected to the exo thigh 86 via a shaft 87. Below
thereof, a fifth element 90, also known as the exo foot, is
connected to the exo lower leg 88 by means of a hinge joint 89.
[0117] It should be noted that the exoskeleton 1000 is in so far
mirror-symmetrical as it contains the above-mentioned elements,
such as exo-hip joint 82, 84, exo-thigh 86, exo-lower leg 88 and
exo-foot 90 as well as the associated joints 81, 83, 85, 87, 89,
twice each, once on the right and on the left side. Because of the
arrangement of the exo-foot 90 (tips to the left below) the usual
forward direction of walking can be recognized. This is relevant
for the designations "right" and "left" in this and the following
illustrations. For clarification, "right side" and "left side" are
indicated accordingly in FIG. 1. It is further pointed out that for
the designs described here, the first element 80a, 80b has both the
function as exo back plate and the function as exo hip plate.
Therefore both terms "hip plate" and "back plate" are used equally
here. In other designs, which are not discussed here, at least one
separate back plate can be provided to actuate the back. Then the
hip can move relative to the back by changing the joint angle
between hip and spine.
[0118] FIG. 2 shows a top view of the exoskeleton 1000, where in
particular its elements are shown, which are located on its left
side. In addition to the described elements, FIGS. 1 and 2 also
show some axes, which result in particular from the arrangement of
the shafts 81, 83, 85, 87 and 89. This will be discussed in more
detail below.
[0119] As shown in FIGS. 1 and 2, a first axis 93 runs through the
shaft 81, so that the first exo hip joint 82 can be rotated around
the first axis 93 relative to the back plate 80a or the
corresponding right or left fastening element 80b. In FIG. 1, the
first axis 93 is marked both on the right and on the left. Further
axes in FIG. 1, 2 are usually only drawn or marked on the right or
left side--depending on where the corresponding axis is best
recognizable. A second axis 94 is defined by the arrangement of the
shaft 83. This allows the second exo hip joint 84 to rotate around
this axis 94 relative to the corresponding first exo hip joint 82.
A third axis 95 is defined by the arrangement of the shaft 85. This
allows the exo thigh 86 to rotate about the third axis 95 with
respect to the associated second exo hip joint. Accordingly [0120]
a fourth axis 96 between the exo thigh 86 and the exo lower thigh
88 according to the arrangement of the shaft 87, and [0121] a fifth
axis 97 between the exo lower leg 88 and the exo foot 90 according
to the shaft 89 are defined.
[0122] The fourth axis 96 is in neutral position (straight, upright
posture; as shown in FIG. 1) parallel or almost parallel to the
mediolateral axis or axis of the user's knee and passes through his
knee joint.
[0123] The fifth axis 97 lies in neutral position (see FIG. 1)
parallel or almost parallel to the mediolateral axis or the axis of
the ankle joint and runs through the human ankle joint. As can be
seen from FIGS. 1 and 2, the shafts 81, 83, 85 are arranged in such
a way that the corresponding axes 93, 94, 95 run through a point 91
on the right-hand side or a point 91 on the left-hand side (in FIG.
2 this is also surrounded by a dotted circle). These points 91
represent the center points of the right or left hip joint. In FIG.
1, 2 another axis 92 is drawn on the right side as well as on the
left side. It is defined thereby that it runs on the one hand
through the center point 91 of the associated right or left hip
joint and on the other hand parallel to the sagital axis.
Furthermore, the axes 92, 93, 94, 95 and the associated joints are
designed and arranged so as to define an angle .phi.1 between the
first axis 93 and the second axis 94 and an angle .phi.2 between
the second axis 94 and the third axis 95. In addition, the first
axis 93 can, under certain conditions, form an angle with axis 92
.alpha. (see FIG. 2), which will be discussed in more detail
below.
[0124] The arrangement of the axes 93, 94 and 95 and the associated
joints forms the core of the exo hip joint. These axes are three
independent rotary axes, all of which intersect at the center 91 of
the user's hip joint. They form a gimbal suspension with the center
of the hip joint as the center.
[0125] The axes 93, 94, 95 of this gimbal suspension do not have to
be perpendicular to each other. This is also not always possible or
desirable, depending on the required working space of the mechanism
or the desired type of actuation.
[0126] The first axis 93 can be oriented relative to the user's
hip, or equivalent to the exo-hip, depending on the desired
application and need, in space through the angles .alpha. and
.beta., or an equivalent transformation, as shown in FIG. 3-5.
However, the first axis 93 always passes through the center 91 of
the user's hip joint. For this purpose, the distance between the
Exo hip and the user must be adjusted accordingly. For
.alpha.=.beta.=0 the first axis 93 is parallel to the sagital axis
and runs through the center of the hip joint 91. For .alpha. and/or
.beta. unequal to zero, first a rotation of the angle .alpha.
around the vertical axis takes place and then a rotation of the
angle .beta. around a vector, with a support point in 91, which is
perpendicular to the plane which intersects the transverse plane
perpendicularly and runs through 92b (according to FIG. 4).
[0127] The figures so far mainly serve to explain the principle of
the present invention. In the following figures several examples of
execution are shown. For the sake of clarity, the reference symbols
are drawn in only to the extent necessary for comprehension.
[0128] FIGS. 6-11 shows a first preferred example of execution.
Here, the first axes 93 of the left and right side both stand at
right angles on the first element 80a, are parallel to the sagital
axis and lead through the centers of the femoral heads. By only
actuating around these first axes 93 a pure abduction and adduction
of the thigh is made possible. In the first example, the angles
have the following values:
.phi.1=35 degrees; .phi.2=70 degrees; .alpha.=0 degrees; .beta.=0
degrees.
[0129] FIGS. 6 and 7 show different views of an exoskeleton 1001
after the first example, whereby a neutral posture is shown.
Thereby the third axes 95 in the neutral position are parallel to
the mediolateral axis. They are therefore responsible for the pure
flexion and extension of the thigh.
[0130] The choice of the third axis 95 in this direction
facilitates the actuation of the thigh when walking or running.
Then most of the work is done here and the largest angle variations
are present.
[0131] The fourth axis 96 and the fifth axis 97 in the neutral
position are parallel to the mediolateral axis. They are thus
responsible for the pure flexion and extension of the lower leg
(fourth axis 96) or the foot (fifth axis 96).
[0132] The choice of the position of the second axis 94 is not
trivial. For an application in walking, standing and running, it
cannot run vertically through the hip joint (then all three axes
would be at right angles to each other in the neutral position),
since a hinge joint would then have to be located either in the
upper body or in the thigh. The angle between the first axis 93 and
the second axis 94 is .phi.0=35.degree.. The angle between the
second axis 94 and the third axis 95 is .phi.2=70.degree.. In this
arrangement, with axis 93 parallel to the sagital axis and with the
third axis 95 of the hip, the fourth axis 96 of the knee and the
fifth axis 97 of the foot 90 parallel to the transveral axis, from
the sum of the angles of .phi.1+.phi.2=105.degree. the maximum
internal rotation of the leg of
.phi.1+.phi.2-90.degree.=105.degree.-90.degree.=15.degree. results.
Then all axes 93-95 lie simultaneously in a plane parallel to the
transverse plane. The maximum rotation of the leg around the
vertical axis is not so easy to determine and essentially depends
on the shape and size of the elements 80, 82, 84. If it is assumed
that the individual parts can penetrate each other, or should be
constructed in such a way that they do not penetrate each other or
collide with each other, then the maximum external rotation of the
foot 90 in the last described case, is
-.phi.1+.phi.2-90.degree.=-35.degree.+70.degree.-90.degree.=-55.degree..
[0133] The difference between maximum internal and external
rotation is 2.PHI.1=70.degree..
[0134] FIGS. 8 and 9 show different perspectives of the first
execution example with maximum internal rotation of 15 degrees and
maximum external rotation of approx. 45 degrees.
[0135] FIGS. 10 and 11 also show different perspectives of the
first execution example with a maximum simultaneous external
rotation of approx. 32 degrees. It enables almost any posture and
movement, even extreme ones. This includes walking, running,
running, jumping, turnaround on the spot, deep lunge, side steps,
cross steps, close combat, sitting on chairs or benches and more.
Structure 1 allows a wide amplitude of the external rotation of the
feet (45.degree. external rotation, 15.degree. internal rotation).
Other constructions can be realized according to the requirements
of an application.
[0136] As already mentioned above, the first axis 93 does not
necessarily have to run parallel to the sagital axis. In
particular, it can be useful to rotate them around the vertical
axis so that the feet can be rotated inwards around the vertical
axis over a larger range. This is the second example of the
execution described using FIGS. 12-17, which has the following
angles:
.phi.1=35 degrees; .phi.2=70 degrees; .alpha.=20 degrees; .beta.=0
degrees.
[0137] FIGS. 12 and 13 show an exoskeleton 1002 in neutral position
according to the second example.
[0138] FIGS. 14 and 15 show the exoskeleton 1002 with maximum
internal rotation of 35 degrees and maximum external rotation of 35
degrees.
[0139] FIGS. 16 and 17 show the exoskeleton 1002 with a maximum
simultaneous external rotation of approx. 28 degrees. The second
example demonstrates how the maximum internal rotation of the foot
can be increased by choosing a .alpha.>0.degree.. In addition,
FIG. 15 shows that the maximum travel range of the second element
82 is increased, and thus the theoretical maximum of the outer
rotation of the foot 90 can be reached. In the first example, this
rotation was limited by the fact that the second element 82 could
collide with element 1. Thus, instead of the theoretical maximum
external rotation of 55.degree., only 45.degree. was achieved.
Thus, the second design example makes it possible e.g. to change
the walking direction faster than the first design example, with
full ground contact without sliding.
[0140] With the exoskeleton 1002, however, the maximum outward
rotation of the feet 90 about the vertical axis is automatically
reduced by the same amount. For outward rotation, the
quantification of the maximum angle again depends on the size and
nature of elements 80a, 82, 84 in particular, as they may collide
depending on the angles selected and your their other specific
geometry. However, this is not the case in the second example (see
in particular FIG. 15, right leg). Here, the maximum possible
inward and outward rotation of the foot is 35.degree..
[0141] In order to allow the widest possible abduction of the
thigh, it is necessary to maintain a lateral distance between the
thigh or hip of the user and the nearest components on the third
axis 95. These parts rotate in a circle around the center of the
head of the femur when the leg is abducted, i.e. rotated
predominantly around the first axis 93. These circles also
intersect the parts of the upper body (hips and upwards). The
greater the radius of these circles between the centre of the hip
joint and the innermost part along the third axis, the greater the
maximum abduction angle of the leg. Likewise, the exo plate 80a
should be kept narrow (in a lateral direction) so that it does not
conflict with the third element 84 if the leg is further
abducted.
[0142] The exo 86 thigh in the preferred embodiment is attached to
the outside of the user's leg. The third element 84 is attached
along the third axis 95 then distally to the exo-thigh 86. This
means that the thigh is attached to the inside of the Cardan
suspension. Then it is easy to attach the user's thigh to it
without too great a distance. The Exo thigh 86 then automatically
has a stop in the swing direction to the rear on the second element
82 or on the third element 84, so that an overturning can be
prevented. If, however, a particularly large distance between the
user and the exoskeleton is required in the area of the third axis
95, e.g. to allow a particularly large abduction of the leg, the
thigh can also be attached to the outside of the third element
84.
[0143] The elements 82 and 84, which are the brackets of the
gimbal, are preferably designed in such a way that the inner
element is smaller than the outer element, in such a way that the
inner element does not collide with the outer element at extreme
angles and external rotation of the foot 90, thus limiting the
freedom of movement. Elements 82, 84 are preferably designed as
"brackets", but can also be designed as circular arcs, so that they
resemble more the elements of a typical Cardan suspension.
[0144] FIGS. 18-23 show another exoskeleton 1003 according to a
third execution example. This has the following angles: [0145]
.phi..sub.1=35.degree., .phi..sub.2=70.degree., .alpha.=20.degree.,
.beta.=20.degree..
[0146] For this case FIGS. 18 and 19 show the exoskeleton 1003 in a
neutral position. FIGS. 20 and 21 show the exoskeleton 1003 with a
maximum internal rotation of 33 degrees and a maximum external
rotation of approx. 37 degrees. In addition is pointed out, that
exo back plate 82 can be shorter than shown here.
[0147] FIGS. 22 and 23 show the exoskeleton 1003 with a maximum
simultaneous outer rotation of approx. 26 degrees.
[0148] By the raised second element 82 the exoskeleton 1003 of this
execution example allows in principle longer steps than in the
previous execution examples. However, these longer steps are
usually no longer covered by the natural working space of most
humans. The space created at the back of the user's legs, however,
also allows other devices such as tactile elements or armour to be
attached to the user's thighs. This design is interesting for
mobile applications because it makes sitting even easier and
reduces the risk of colliding with the environment. The structure
also allows, for example, deeper kneeling without the feet 90 of
the exoskeleton colliding with the hip elements.
[0149] The examples of execution described so far are preferred.
However, there are a large number of other configurations which
refer to all the execution examples described so far. Some of these
improvements are briefly discussed below.
[0150] In the previous execution examples, the elements 82 and 84
are designed in such a way that between the first axis 93 and the
third axis 95 only one further axis is provided, namely the second
axis 94, which results from the joint 83 between the elements 82
and 84. It is also possible to use not only provide a second axis
94 between preserved axes 93 and 95, but to introduce additional
axes (e.g. axes 94a, 94b, etc.) using more than 2 brackets or arcs.
Especially if all or some of these elements can be completely
folded into each other, this has the advantage that the difference
between maximum inner rotation and maximum outer rotation of the
corresponding foot 90 can be increased.
[0151] FIGS. 24-26 show different perspectives of such an example,
in which element 82 is divided into three parts, which are here
referred to as 82a, 82b and 82c. Each of these parts is rotatably
connected to its neighboring part, resulting in the axes 94a, 94b
and 94c. Preferably each axis is updated. This can also be done by
actuators on the not shown elements 80 or 86. The smaller elements
in the example cover an angle of 30.degree. each and the larger one
an angle of 60.degree.. With this construction a foot could be
rotated (by means of the external or internal rotation of the hip
joint) by 60.degree. inwards as well as outwards (for a hip plate
with .alpha.=.beta.=0.degree.). It is possible to attach elements
81, 82a, 82b, 82c, etc, 84, 86 in any order inside or outside to
each other. In addition, the angles .phi..sub.i of the elements can
be different from each other. Elements 82-84, which are arranged
from the inside to the outside as in the example according to FIGS.
24-26, can never intersect, independent of the angles .phi..sub.i
used. If however at least some of elements should be arranged from
outside to inside, cutting of each other can be avoided, if the
next element (e.g. element 82c is next element of 82b) covers a
much smaller angle than previous element. It is also possible that
element 82a is outside of the following elements 82b, etc. but is
first attached to element 80. By using some of these measures or by
combining them, it can be prevented that the diameter of the entire
hip joint increases too much with increasing number of
elements.
[0152] Due to the use of more than 3 axes for the hip joint, there
is generally no longer a unambiguous assignment for the choice of
the driven axis angles (joint angles). However, it is preferable to
correlate the angle between axis 93 and axis 95 tabularly or
functionally bijective with a vector of the to be actuated angles
(joint angles) of axes 94a, 94b, etc. This ensures that the
mechanism behaves safely and predictably. In general, it is
necessary that element 84 does not deviate too far from the
horizontal.
[0153] This would impede the free swinging of the leg. This type of
actuation can also be operated in the other direction to increase
an external rotation of the hip. This type of actuation can also be
operated in the other direction to increase an external rotation of
the hip. Then, however, it can happen that the hip elements of the
left and right leg easily come into conflict with each other.
[0154] It is generally important that the last element (here 84) to
which the exo thigh 86 is attached, in all states of the hip joint
mechanism, allows the exo thigh 86 to swing during gait. Since in
the preferred execution examples the exo thigh 86 is fastened
internally to the third element 84, the area of the third axis 95
of element 84 is preferably flat on the inside. This corresponds to
the representations used here. However, element 84 may be round,
especially if the exo thigh 86 should be attached externally, or if
the distance between the exo thigh 86 and element 84 along the
third axis 95 should be so large that a free swing of the exo thigh
86 should not be significantly restricted.
[0155] Due to a particularly wide choice of hip elements,
preferably as segments of spherical shells, the hip mechanism can
correspond even more closely to a foldable part of a spherical
shell. This can be used e.g. as protection or armour.
[0156] In the shown exoskeleton forms 1000, 1001, 1002, 1003, the
third element 84 is formed in such a way that the two brackets 84,
84b are arranged almost perpendicular to each other. As a result,
the third element 84 protrudes quite far sideways in the various
movements. In order for the third element 84 to occupy less lateral
space, it is possible to shorten the first bracket 84a, preferably
so that the second bracket 84b runs parallel to the sagittal axis
in the neutral position. This facilitates the swinging of the arms
when walking and saves weight. This facilitates the swinging of the
arms when walking and saves weight. For this purpose, the angle
between the brackets 84a and 84b is to be adjusted accordingly.
[0157] For reasons of clarity, the necessary bearings, axle mounts
and actuators are not explicitly specified in the examples
described. Actuators can be mounted in or on any element.
Correspondingly, fixed axle connections or e.g. ball bearing
connections become necessary. As shown in the first example,
however, it is preferred that an actuator in an exo lower leg 88
actuators the fifth axis 97 to the exo foot 90. A first actuator in
exo thigh element 86 actuators the fourth axis 96 of the knee
joint, a second actuator in exo thigh element 86 actuators the
third axis 95 of the exo hip joint, an actuator in element 84
actuators the second axis 94 of the hip joint, and an actuator on,
in, or on the exo hip or exo back plate 80a actuates the first axis
93.
[0158] Below are described novel actuators which can be used to
drive all joints of the described exoskeleton in the preferred
design. Regardless of this, the mechanism of the exoskeleton can
also be driven by other actuators. This includes normal geared
motors, linear actuators, hydraulic or pneumatic cylinders, direct
drive by gearless torque motors, drive by cables and Bowden cables
and rollers and more. Particularly advantageous is the drive via
motors with back-drivable ball-bearing worm gears (ball worm, ball
worm gear, recirculating ball worm drive according to U.S. Pat. No.
3,468,179 A), with global roll spindles or "harmonic drive"
gears.
[0159] Especially the exo-foot 90 generally can have an additional
axis and necessary components with which pronation and supination
can be actuated. A particularly advantageous further development of
the Exo-Foot is described below and is called Exo-Foot 9000.
[0160] It can be advantageous if the two axes of the Exo 86 thigh
are not parallel to each other. However, the fourth axis 96 must
always be parallel or almost parallel to the axis of the knee
joint. However, the third axis 95 can generally be oriented
arbitrarily. In this way it can be influenced, according to the
effect of the angle .alpha., to what extent the external and
internal rotation of the leg is possible. The described hip
mechanism, with at least 3 axes, which intersect in the center of
the hip joint, is in practice quite tolerant regarding deviations
in the axial direction. Also, the user may be larger, smaller, too
far forward, or too far back, too far left, or too far right of the
ideal position. This can be used to use an exoskeleton of one size
for more than one user. Also the adjustment of the center distances
and angles to a special user is facilitated. However, the principle
of the mechanism is not lost by these deviations. It is intended to
design mounting points and bearings of axles to be displaceable and
adjustable. It is advantageous to be able to adjust the distance
from the user's back to the hip plate, as well as its vertical
position, in order to align the center of his hip joint with the
intersection of the axes.
[0161] Due to the largely athropomorphic nature of the exoskeleton,
it is possible to design most of the described elements in such a
way that they encompass the user, and not only, as in the
illustrations, stand laterally to him.
[0162] It should be noted that, surprisingly, with the preferred
simple hip mechanism (e.g. FIG. 1-25), also in connection with the
described exoskeleton, generally only extremely low torques are
required to actuate the second axis 94. This is also true if the
exoskeleton, as in teleoperative applications, has to carry the
entire weight of the user, while it is itself, on the hip or back,
carried by a movement simulator. If, for example, the user's weight
rests only on an extended leg and is transferred to an exo leg
entirely by means of his foot on the foot element of the
exoskeleton, the centre of gravity of the leg and of the user is
always perpendicular under or above his loaded hip joint (point
91). If .beta.=0.degree., and the weight of the elements 82 and 94
can be neglected compared to the other weights, only changes in the
joint angles of the axes 93 and 94 can change the potential energy
by raising the center of gravity. For this, considerable torques
are required. The actuation of axis 94, however, is also possible
without changing the potential energy if axes 93 and 95 are moved
in such a way that a single external rotation or internal rotation
(external or internal rotation of the hip joint) of the foot is
achieved. The centre of gravity remains at the same height and
therefore no work is performed and no axial torques occur. However,
since the position of elements 82 and 84 in a gravity field
generally changes due to the modified joint angle of axis 93, a low
axial torque must be applied or absorbed by the actuator. However,
the transversal torques on this axis are generally very high when a
leg is loaded with significant parts of the body weight. The joints
must be of a correspondingly strong design. Friction forces in the
bearings, which are low, must also be overcome. The external or
internal rotation of the leg is force-wise only weakly developed in
humans. Therefore, the torques to be actuated of axis 94, which
mainly serves this degree of freedom, are also low compared to
other torques occurring in the exo legs. Accordingly, actuators
there can be smaller and weaker.
[0163] Similarly, the axial torques of a body with several elements
82, 82b, etc. (FIG. 24-26) are only low. The rather small actuators
can therefore be easily located on or in these elements for all
configurations, but can also be remote (Bowden cables). This also
applies if only one element 82 is used. Even if .beta. should not
be equal to 0.degree., these axial torques are low, as long as
.beta. remains small.
[0164] All described structures and combinations of properties can
be used not only for exoskeletons but also for humanoid robots and
virtual avatars or virtual machines. In virtual cases, real
components must be replaced by corresponding virtual ones.
[0165] As already mentioned, the previous description of the
preferred exoskeletons 1001, 1002, 1003 did not include the
representation and description of associated actuators.
Particularly suitable actuators are described in the following.
[0166] FIGS. 27-31 shows a first execution example of a new
actuator 2001.
[0167] FIG. 27 shows in a perspective view the actuator 2001 closed
from the front, i.e. inside its housing.
[0168] FIG. 28 shows the actuator 2001 from a similar perspective
as before. Here, however, parts of the housing are removed, namely
a front base plate 106a and a base frame 107.
[0169] FIG. 29 shows the actuator 2001 in a similar way as before.
Here a front chain 110 is missing as well as elements 108, 109,
104a and 105a, which concern their drive.
[0170] FIG. 30 shows the actuator 2001 in perspective view from the
back, without housing parts.
[0171] FIG. 31 shows the actuator 2001 in side view with the front
view without the front base plate 106a.
[0172] The actuator 2001 has two parallel chains 110, 113, which
run on one side of the actuator 2001 in a plane with a ball screw
114 and at the same distance to it. The actuator 2001 is designed
in "integral construction", which means that the housing parts
106a, 106b and 107 perform the functions of the basis, i.e.
structural functions. However, parts of this function are here also
taken over by a linear guide support 121 and by the frame 123 of a
motor 124, which are mounted in a force-locked manner to the base.
A nut 117 is force-locked to a connecting block 118, which is
mounted in a force-locked manner to chains 110, 113 by suitable
means. This actuator 2001 has a dedicated driven shaft 101, a
dedicated idler shaft 102 and a dedicated fixed shaft 103. Driven
sprockets 108, 111 are connected to a driven axle 101 by suitable
means, such as direct (welding, screwing) or indirect (hub,
clamping set, spoke hub). The 101 axle and sprockets 108 and 111
can also be manufactured as a single component. The driven shaft
101 is connected to the base by suitable bearings 104a, 104b so
that it can rotate around its axis but cannot shift. The dedicated
idler shaft 102 is also mounted in the same way, by means of
bearings 105a, 105b. The free-running sprockets 109, 112 are
preferably mounted in a friction-locked fashion to the deflection
shaft 102. However, the bearing arrangement can also be different,
such as individually or together on an internal axis and not on an
external axis as is the case here. It is also possible to dispense
with the dedicated fixed shaft 103 (it is used to attach other
actuators to the example actuator) and to provide other
attachments. It is also possible to use the fixed shaft to support
the bearings of the free-running axle or free-running sprockets (as
e.g. in the actuator 2003).
[0173] In Aktuator 2001, the sprockets and chains on one side can
be dispensed with. Then, however, depending on the given load,
considerable transverse torques can occur, which must be absorbed
by the nut and linear guide. Basic elements, axles, bearings, etc.
should then of course be adapted to the new geometry, as space and
weight can be saved.
[0174] FIG. 32 shows a side view of an actuator 2002 for a second
execution example. This actuator 2002 corresponds almost completely
to the actuator 2001 described above. However, the driven axis is
shorter here and the driven component X of an exoskeleton or robot
is fastened to the driven axis inside the housing, using suitable
space-saving means. The housing is modified accordingly. Variations
as with the actuator 2001 are of course also applicable here.
[0175] A third actuator 2003 after another execution example is
shown in FIGS. 33-37. FIG. 33 shows actuator 2003 completely in
perspective view, but without optional housing
[0176] FIG. 34 shows the actuator 2003 from above, wherein a linear
guide support 121b is particularly characterized which is combined
with the base and which is separately shown in FIG. 35 as a side
view.
[0177] FIG. 36 shows a side view of the actuator 2003 without the
front parts 108, 109, 110
[0178] FIG. 37 shows a perspective view of the actuator 2003, but
without the front parts 108, 109, 110 and without the bearings 104c
and 125a.
[0179] The actuator 2003 is designed in "differential" design. So
it does not necessarily need a housing. However, a suitable housing
can be connected to a 121b linear guide support, which is combined
with the base, to increase the load capacity. The linear guide
support 121b combined with the base is now, in comparison to the
linear guide support 121 shown above, designed in such a way that
bearings and axles can also be attached to it. The actuator 2003
has a central bearing 104c, which carries the driven shaft and
allows only the axial degree of freedom. The fixed shaft 103 is
here firmly connected to the linear guide support 121b. The
free-running sprockets are fastened to it with suitable bearings.
This Actuator 2003 can of course also be implemented in such a way
that a dedicated idler shaft and a dedicated fixed shaft are used,
as in Actuator 2001. All shafts would then be mounted with 121b
suitably connected, by bearing or fixed. Also the actuator 2003,
like the actuator 2001, can be built in a one-sided variant,
similar to FIG. 36 (without free, unused bearing and detail
adjustments). All actuators shown here can be manufactured in
integral or differential design.
[0180] A fourth actuator 2004 according to another execution
example is shown in FIGS. 38-41.
[0181] FIG. 38 shows a perspective view of the actuator 2004.
[0182] FIG. 39 shows a side view of the actuator 2004 without the
front base plate 106a.
[0183] FIG. 40 shows a top view of the actuator 2004 without base
frame 107.
[0184] Actuator 2004' is a modification of Actuator 2004 with only
one linear guide.
[0185] The 2004 actuator demonstrates a space-saving design with
only one chain marked 113. The two linear guides 119 are attached
directly or indirectly to the chain 113 by suitable means. They are
attached here above the chain 113. The double arrangement doubles
the load capacity without affecting the length. Due to their
position, the linear rails 119 can be significantly longer than the
straight section, and therefore longer carriages or double
carriages can be used at greater distances from each other. All
this increases the load capacity for torques. Although the ball nut
117 of the recirculating ball screw 114 must absorb considerable
torques, since it is firmly connected to the bearings of the linear
guide by suitable means, these torques have little effect on
operation. In a variation 2004' this actuator can also be operated
with only one linear guide 109 (FIG. 41), if the associated
limitations are accepted. Nut, linear guide carriages or carriage
and connection block can also be manufactured as one component. The
bearings of the ball screw are directly or indirectly connected to
the base by suitable means, in the illustration with the base
108.
[0186] A fifth 2005 actuator after another execution example is
shown in FIGS. 42 and 43. FIG. 42 is a perspective view on actuator
2005 and FIG. 43 is a side view.
[0187] The actuator 2005 corresponds to the actuator 2004' with
only one linear guide (see FIG. 41). The chain 113 is attached
directly or indirectly to the linear guide carriage. Here, the
linear guide is preferably moved in a plane with the chain 113 and
the ball screw so that the torques along a transverse axis become
practically zero. This case is not fully realized in FIG. 42 for
drawing reasons, since the center of the recirculating ball bearing
guide of the linear rail is not in the plane of the chain center
and the axis of the ball screw plane. For this purpose, the spacer
126, which is firmly connected to the base and the linear rail or
can be part of it, would have to be slightly thicker. As can be
seen, the base/housing can partly be designed even narrower. Of
course also here a differential construction can be chosen. You are
also free to choose between exclusively dedicated axes or
non-dedicated axes. Linear rail and ball screw can change places
here (as with the 2006 actuator described below). Then the chain
113 is attached directly or indirectly to the nut of the ball
screw. In such a design, however, the effects of torque on the nut
and linear guide are greater.
[0188] A sixth actuator 2006 after another execution example is
shown in FIGS. 44 to 46. FIG. 44 is a perspective representation on
actuator 2006 and FIG. 45 is a side view. Furthermore, FIG. 46
shows an actuator 2006' with only one guide rail 119.
[0189] In the actuator 2006 or 2006', one or two linear guides 119
run approximately parallel to the ball screw 114, which is led
close to the chain to reduce torques. All parts are suitably
connected to the base and axes corresponding to the other
examples.
[0190] A seventh actuator in 2007 after another example is shown in
FIGS. 47 to 49. FIG. 47 is a perspective representation on actuator
2007 and FIG. 48 is a side view. FIG. 49 also shows an actuator
2007' with only one guide rail 119.
[0191] In the actuator 2007 or 2007', one or two linear guides 119
run below the ball screw 114, which is led close to the chain 113
to reduce torques. All parts are suitably connected to the base and
axes according to the other examples. This saves space compared to
actuator 2006.
[0192] All these actuators can be converted to serial elastic
actuators by known means, especially known spring elements and
their coupling to ropes, rods, axles, etc. An example of this is an
actuator 2008, as symbolically indicated in FIGS. 50-52. Elements
not shown here are to be supplemented according to the previous
examples. The decisive factor is that spring elements 127 are
preferably fitted coaxially to a section of the chain 113. The
coaxial fixing makes the guidance of the springs 127 unnecessary or
very simple, since there are hardly any transverse forces. The two
springs 127 are connected here on each of their sides with a
connecting block, which has abutments and is marked 118b here. On
the other side they can either be connected directly to the chain
113 or, as shown in FIGS. 50-52, with a chain-spring connection
element 128. This is connected to the chain 113. Disc springs, leaf
springs, elastomers, cush drives, etc. can also be used as springs.
The use of these elements also reduces negative influences due to
the polygon effect. The chain 113 can also be attached as before to
a nut or linear carriage etc. and the springs can be part of the
chain. An associated spring mechanism may also be coaxial with the
ball screw as part of the connecting block. This is particularly
easy to implement if the ball screw is loaded axially only, since
there is no need for additional strong guides for the springs. As
known, the spring can also be a torsion spring of the driven shaft
or a hub mounted there (which in turn holds the driven sprockets).
The driven axis can also be attached to a torsion spring to which
the next driven element of the robot is attached. The torsion
spring can also be part of this next element of the robot. In FIG.
51, 52 an element 128 is connected to the chain and the springs
with two sides of element 118b. The chain 113 must be passed
through 118b here. The structure can also be reversed, where 128
becomes part of 128b, and the spring holders of 118b are connected
to the chain and one spring each, or the springs are directly
integrated into the chain and the chain is driven between the
springs.
[0193] It is generally advantageous to attach not only the drive or
actuator for the third axis 95, but also for the fourth axis 96
(knee joint) to the exo-thigh 86 (or to the thigh of a humanoid
robot). These two actuators can be stacked on top of each other.
However, it is preferable that they share the axles for driven
wheels and pulleys. A driven axle then holds the bearings for the
deflection rollers of the other axle. FIG. 53, 54 is an example of
a suitable actuator for 2009 in which bearings 129 for a
freewheeling sprocket and bearings 130 for axles are also shown. It
should be noted that the principle of Actuator 2009 can be applied
to all other actuators presented and implied here. It is preferable
to install a torque sensor, such as a suitable sensor hub, between
the bearings of the idler pulleys and the axles. This allows
residual torques of the idler pulleys rotating relative to the
shaft to be measured and used to correct measured main torques of
this shaft. Preferably, the free-running sprockets are not mounted
individually as shown in the picture, but are first mounted on a
common axle, which is then mounted opposite the coaxial driven
axle. It is also possible to measure axial torques acting on the
driven shaft at various points, e.g. by means of strain gauges, and
thus separate individual influences on the shaft. It is of course
also possible to integrate actuators with multiple bases of
differential or integral designs in one housing.
[0194] Another arrangement of the actuator provides that the driven
shaft drives a Bowden cable mechanism. For this purpose, e.g.
suitable pulleys are preferably fixed directly at this shaft, or
the rope is wound directly around the shaft. The shaft or rollers
may have suitable cable guides/grooves. Several ropes can be used,
each for the same or opposite direction of pull. The rope or ropes
can be anchored to the axle or pulley by known means to ensure the
transmission of force. Bowden cables can be used to route the ropes
in such a way that one or more additional pulleys or axles are
driven at remote points. Here, too, known means can be used again,
such as spring-loaded Bowden cables or spring-loaded rollers, to
achieve the properties of an ordinary serial elastic actuator. The
pulley diameters of the Bowden cable mechanism can now be used to
further influence the gear ratio by known means. It is also
possible to transmit the power via ropes, but without Bowden
cables, but only via pulleys and corresponding means.
[0195] Similar to the Bowden cable mechanism, two "hydraulic-rotary
transducers" (HRT) can also be used. One HRT on the actuator is
rotatably driven by the driven shaft and generates pressure and
underpressure in the two connected pressure lines. At the remote
HRT, this causes a corresponding movement of the actuated joint.
This has the advantage over Bowden cables that lower losses occur
and the system reacts less flexibly.
[0196] The free-running sprockets, rollers, cylinders, etc. are
always shown here in such a way that they have the same diameter as
the driven sprockets, rollers, cylinders, etc. However, they can
have different diameters. In addition, several small free-running
idler pulleys can be used. This allows, for example, the available
stroke to be increased, the path of the chain, rope, etc. in the
housing to be influenced in such a way as to create axes for
further shafts or devices, such as power electronics. The free
running rollers (etc.) can also be replaced by alternative
deflection elements such as slide rails, Bowden cables, Teflon
guides, channels in the base, etc.
[0197] Usually suitable tensioning devices are necessary to
pretension chains, ropes, belts, etc. These can preferably be
mounted on the side of the actuator that is opposite of the ball
screw or integrated into the support of the axes in order to
slightly change the distance between the axes. These means may
include spring elements.
[0198] An advantage of all described actuators is that they have a
constant gear ratio from motor to driven axis. Especially for
joints which have to be actuated over a large angular range this
can be advantageous. This makes it possible to build robots and
exoskeletons that are more articulated than before. Also, the
position of the actuator in the exoskeleton or robot does no longer
directly influence the previously angle-dependent transmission
ratios. This simplifies the design process.
[0199] A further advantage of the mentioned execution examples is
that almost the entire length of an actuator is now available as
the usable travel range of the ball screw. This permits larger
actuating angle ranges with constant diameters of the rollers of
the driven shaft. Conversely, larger roller diameters and thus
larger power transmission ratios can also be achieved. This can
reduce the number of actuators and/or motors in robots and
exoskeletons and/or increase strength or power.
[0200] A further advantage of the design examples mentioned is that
the chain is always mounted close to the guided nut. This reduces
oscillations and uncontrolled elastic behaviour. In addition, the
actuation is completely identical in both directions; and do not
show a stable traction behavior in one direction and an unstable
push behavior in the other. This increases the controllable forces
and speeds.
[0201] It is possible to replace the ball screw and the brushless
DC motor with a linear motor (such as a linear, electric, brushless
motor or piezo actuators). The high response time of this drive can
be advantageous. It is also possible to stack several linear motors
and have them drive a chain, ropes, etc. together, thus making use
of the available volume to enable high forces and power.
[0202] It is also possible to integrate electrical or mechanical
brakes into the actuators. This is preferably done directly on the
motor. Because low braking torques there result in high braking
torques on the driven axle.
[0203] All actuators can be equipped with obvious means with
position encoders, angle encoders, torque sensors and limit
switches. Cables are preferably routed from one actuator to the
next through the shafts. For this purpose, openings may be provided
in the shafts for inserting and removing cables. For this purpose,
openings may be provided in the shafts for inserting and removing
cables. All actuators can be realized with chains, ropes, belts and
suitable deflection and tensioning devices.
[0204] The actuators can also be used for other robotic systems, or
any other application requiring high torque transmission. In order
to achieve greater forces, two ball screws can also be used, each
of which has the means described to attach a common chain.
[0205] The spindles are then located on opposite sides of the
sprockets (e.g. mirrored on the plane of the axis of the driven
axis and the free axis) and each drive a different straight section
of the chain. The nuts then drive the chain in the same direction
of rotation, but in the opposite direction in space. If there are
several straight sections of the chain, if there are several
rotating wheels or driven wheels, more than 2 spindles, motors,
etc. can also be used. Likewise, several spindles can drive
parallel mechanisms, each of which drives a common drive shaft.
This corresponds approximately to the illustration in FIG. 53, 54,
except that there is only one driven shaft which is driven by all
chains, motors and spindles etc. The storage would have to be
adapted to this situation.
[0206] In order to achieve unlimited actuating ranges, it can be
provided that, for example, in a system with 2 ball screws which
drive a common chain, only one spindle at a time must engage in the
chain with suitable means in order to perform work. The other
spindle can then retract the connected nut and chain gripping
mechanism, engage the chain, and begin to perform work or exert
force. Then the other gripping mechanism can release itself from
the chain, move to its new starting position, grip the chain and
start performing work on the chain, or exert force. This procedure
is similar to turning a steering wheel with two hands, where only
one hand is needed at a time to keep control of the steering wheel.
The torques, forces, speeds and/or positions on the chain must be
precisely controlled, especially when engaging and disengaging, so
that no discontinuities occur. Similar mechanisms can again be
realized with ropes or belts. The design of suitable actuators and
gripper profiles for gripping and holding chains etc. is obvious
(e.g. rope clamps, cableways), pliers with tooth profiles on both
sides. Also several ball screws can be used in parallel (similar to
FIG. 53, 54, but with only one driven axis) to drive a common
shaft. However, also here the structures can be designed in such a
way that they can engage and disengage in the chains, etc., and
thus arbitrary axial travel of the driven axis can be achieved.
Likewise, the sprockets, axles, hubs, etc. can be equipped with
coupling mechanisms. Then the chains can remain connected to the
nuts/ball spindles and the sprockets or shafts can be decoupled and
retracted before being operated again in drive direction and
engaged to perform work or generate forces. The principle of
engaging and disengaging drives of several rotating ball screws can
also be applied to actuator examples with only one-sided chain
loading. Then such an actuator, with two driven sprockets and two
ball screws, is not or not substantially larger than an actuator
with chain loading on both sides. Here it is also possible to use
only one chain (or structure of phased chains), which is driven
from one side each by a nut and ball screw. Here it must be
prevented that the gripping mechanisms collide, if one is decoupled
and driven back.
[0207] Exoskeletons for the teleoperation, i.e. to control
governors in a virtual (avatars) or real environment (humanoid
robots), use motion simulators to exert static or time-varying body
accelerations on the user. Gimbal suspensions are also used for
this purpose.
[0208] The following figures describe preferred motion simulators
that can be used with an exoskeleton.
[0209] FIG. 55 shows in a perspective view of a motion simulator
3000 to which an exoskeleton 203 with back mounting is attached.
The Motion Simulator 3000 essentially consists of two main parts,
namely [0210] a translation unit 210 with actuators 250, 252, 254
as well as suitable drive means, such as motors, shafts, ropes,
etc., which are not shown here. This enables translational
movements along the arrows P1, P2 and P3. [0211] a rotary unit 211
comprising a first rotary member 200, a second rotary member 201
and a third rotary member 202. These are each mounted rotatable
relative to neighboring elements.
[0212] In the following, mainly the rotation unit 211 is described.
FIG. 56 is also a perspective representation of the motion
simulator 3000 and is used in the following to describe different
rotation axes.
[0213] The first rotation element 200 is mounted with its first end
at the linear actuator 254 rotatably around a first rotation axis
205, which in normal operation is essentially vertical and
corresponds to the vertical axis of the linear actuator 254. At the
second end of the first rotation element 200, the second rotation
element 201 is mounted rotatably around a second rotation axis 206.
At the other end of this second rotation element 201, the third
rotation element 202 is bearing-mounted around a third rotation
axis 207. At the other end of the third rotation element 202, the
exoskeleton 203 is mounted rotatably about a fourth rotation axis
208. It should be noted that an appropriate bearing must be
provided and arranged for each of the rotary axes mentioned. This
is generally known to the expert, so that it will not be discussed
further.
[0214] FIG. 57 shows that the rotation axes 205, 206, 207, 208
intersect at a point 220 and which angles are formed between the
individual elements or axes, namely: [0215] the rotation axes 205
and 206 form an element angle 212 [0216] the rotation axes 206 and
207 form an element angle 213 [0217] the rotation axes 207 and 208
form an element angle 214.
[0218] The sum of the element angles must be greater than
180.degree. to avoid a gimbal lock and to allow the user in the
exoskeleton to assume all possible spatial orientations. In the
figures, the rotation elements 200, 201, 202 are each equipped with
only 2 axle bearings or axle mounting points (and not with two
opposite ones on each side of the user). In particular, the first
rotary element 200 and the second rotary element 201, counted from
the attachment to the translation unit 210, can, however, also have
2 axle attachment points or axle bearings if they should be added
mirror-symmetrically. However, it is advantageous not to supplement
the second rotation element 201 in such a way and instead always to
orient it in such a way that the legs of the exoskeleton are
preferably oriented away from it. The second rotary element 201 is
oval shaped to save weight and space. This, however, limits the
size of the next rotation element 202 so that it can no longer be
designed as a full or semicircle, otherwise the user inevitably has
to collide with it.
[0219] According to the invention, the third rotation element 202
is designed as a simple, short and small arc or bracket, so it has
only two fixing points for axles and axle bearings. In order to
achieve the smoothest possible motion behavior in areas where the
rotation unit 211 with only 3 axes would experience a gimbal lock,
the angle of the third rotation element 202 is selected as large as
possible.
[0220] In general, the exoskeleton 203 can then no longer rotate
360.degree. around the axis 208 without colliding with the third
rotation element 202 or colliding when the user adopts certain
postures. However, these collisions must and can be prevented. In
general, it is not necessary to actuate the 208 axis by
360.degree.. (For smaller element angles 213, however, 360.degree.
actuation is possible. Then, however, the mentioned problems with
high speeds and accelerations occur again increasingly.)
[0221] As can be seen in FIG. 58, the third rotation element 202 is
preferably attached to exoskeleton 203 in such a way that it sits
quite high overall, and the part which is attached to the second
rotation element 201 sits at the bottom relative to the attachment
point on the exoskeleton (in neutral position of the rotation unit,
as shown in the figures). However, other types of mounting are
possible. The figures also show that the third rotation element 202
is preferably mounted at an angle to the exoskeleton 203. This is
achieved by a back mount 204, which can be described by two angles
analogous to the axis 93 of the second element 82 of the hip (FIG.
2). It is important that the element axis 208 runs through the
common intersection point of all element axes 205, 206, 207, 208.
This lies preferably in the body of the user, e.g. in his head, or
in his torso. Preferably a starting angle is chosen for the third
rotation element 202 in the normal position and then a suitable
back mount 204 is designed. This mount 204 then forms a rigid unit
with the back plate (or hip plate, etc.) of the exoskeleton 203. In
the example setup, element 202 is inclined by 30.degree. from the
vertical. This angle may also be different if element 202 does not
collide with the back plate or other parts of the exoskeleton 203.
The actuation angle of axis 208 must then be restricted to an area
that is so small or smaller that the third rotation element 202 can
never collide with the back plate. It is usually sufficient to
select this range significantly smaller than the maximum if the
effective remaining sum of the joint angles exceeds 180.degree..
All other axes 205, 206 and 207 can be actuated over full
360.degree..
[0222] In the preferred design example, the element angles have the
following values: Angle 212=90.degree.; angle 213=90.degree.; angle
214=30.degree. (see FIG. 57).
[0223] The control is done with methods of inverse kinematics with
boundary conditions. Axis 208 is preferably controlled so that in
the preferred execution example it is never deflected more than
+/-35.degree. with respect to the back plate of the exoskeleton (in
the illustrations, this is 30.degree.). This angle is used to
control the mechanism so that the user with his arms is kept away
from the second rotation element 201). Soft or hard restraints or
potentials can be used for this purpose. The control method is, for
example, to first take a target orientation, e.g. the spatial
position of an avatar, or a corresponding target value from a
motion cueing process. In the computer, in a dynamic simulation of
a model of the motion simulator or parts thereof, the given target
position of the user in the exoskeleton is applied as boundary
condition or restrain to the exoskeleton or end effector of the
motion simulator. Then the simulated movement simulator reacts in
such a way that "automatically" the correct joint angles are
adopted in order to achieve the required orientation. These joint
angles can then be used as target angles for the real motion
simulator. Of course, this procedure can also be simplified and
accelerated mathematically by using precise mathematical models
rather than numerical simulations. An advantage of this design is
that the third rotation element 202 can be located very close to
the exoskeleton. This makes it small, stiff, light and close to the
center of rotation. It is therefore easy and quick to actuate. It
can have a very large element angle, which would require a much
larger and heavier element further out. Collisions can be prevented
by actuating the 208 axis in an angle range smaller than
360.degree.. Previously, the need to avoid collisions motivated the
use of larger elements. Despite the limited angular range of the
208 axis, the mechanism covers the space of all rotations so well
that fluid movements with only low speeds and accelerations of all
205-208 rotary elements are possible. A gimbal lock is avoided and
the system always behaves "good-natured". The use of the described
light element close to the user has further advantages with regard
to the speed of the gimbal suspension. By the use of 4 axes and 3
elements, or more, for each or almost every orientation of the user
in space, there are infinitely many, densely adjoining, actuation
angles of the gimbal suspension to produce this orientation of the
user. Should a new spatial position/orientation of the user be
adopted quickly, generally all elements of the rotation unit must
react quickly. However, this is particularly difficult with the
outer elements, because they are usually large and heavy themselves
and have large moments of inertia, on the one hand, and on the
other hand, the entire inner structure of the motion simulator acts
on them. If the inertia (approximated or precise) of the individual
elements is also taken into account in the kinematic control of the
rotation unit described above, it can be seen that soft
acceleration behaviour occurs for the larger elements even with
rapid changes in orientation and sudden reversal of the angular
velocities. They can run out slowly, so to speak, and slowly reduce
their rotational speed before reversing it. Fast or sudden changes
occur almost exclusively in the innermost or second innermost
actuator. These are small and can react quickly. This makes it
possible to select larger, stiffer outer elements of the rotation
unit with possibly weaker motors without slowing down the reaction
of the system. Alternatively, faster movements can be
performed.
[0224] In order to expand this advantage further, additional small
elements can be attached to the inner element 202, just as this
element 202 is attached to the exoskeleton. These additional
elements, too, are generally only actuated over angle ranges
smaller than 360.degree., especially for the desired large element
angles. These additional elements, too, are generally only actuated
over angle ranges smaller than 360.degree., especially for the
desired large element angles. Thus even faster reactions of the
inner elements can lead to the fact that the outer elements may
react slower etc. and can be laid out accordingly.
[0225] Alternatively, it is possible to design only a gimbal
suspension with 4 axes of 3 elements or more, so that individual
element angles can be arbitrary, but the sum is above 180.degree.,
but preferably below 270.degree.. This allows the resulting
mechanism to avoid a gimbal lock. This allows the resulting
mechanism to avoid a gimbal lock. The element angles are then
generally smaller than 90.degree., the choice of previous motion
simulators. The smaller the angle sum, the faster the joints have
to be actuated and accelerated, but the construction becomes
lighter and less inert. If only a limited orientation space is
required, the sum of angles can be less than 180.degree..
[0226] Also with only 2 elements and 3 axes of the gimbal
suspension it is possible to avoid a gimbal lock and still be able
to take almost any orientation in space without high velocities
during the actuation of the elements need to occur. For this, the
sum of the element angles must first be greater than 180.degree..
If both element angles are equal, there is only one position, with
folded elements, where the axes are parallel, and degrees of
freedom are lost. The larger the sum of the angles, the
better-natured the speed and acceleration behaviour in the
orientation space. All axes can still lie in one plane, but there
are alternative joint angles which describe the same spatial
position/orientation of the user and where the axes do not lie in
one plane. This design saves actuators, weight and costs compared
to designs with 4 axes.
[0227] The axis bearing of the elements shown here are very short
and flat. However, they can also be long and thus e.g. resemble
cylinders and thus bridge distances between the elements or from
one element to the exoskeleton.
[0228] The described types of gimbal suspension can also find use
for any other application.
[0229] The previously described exoskeletons can be further
improved by a special design of the feet 90. Exoskeletons--and also
humanoid robots--usually require two degrees of freedom of the foot
in order to come close to human mobility. This requires
corresponding effort during actuation, which in turn requires
corresponding space and weight.
[0230] FIG. 60 shows a preferred design example for an Exo foot
9000 according to the invention. This foot 9000 has an axis 910
which is approximately parallel to the transverse axis of the
user's ankle joint. Parallel to this axis, preferably a shaft 902
is used to attach the foot to an actuator. Alternatively this shaft
902 is part of the actuator.
[0231] Supination and pronation of the foot can therefore not be
actuated. In order to allow movement of a similar kind, although
not actuated, the sole 904 of the foot 9000 is rounded off
laterally, as shown in FIG. 61.
[0232] This is preferably done on the basis of a profile of two
circular segments with different radii of circles or circular-like
shapes, which have their centres close to the ankle joint of the
user and lie parallel to the frontal plane of the user (FIG. 63).
Smaller circle diameters facilitate unrolling, larger diameters
allow a safer stand. It is preferable to facilitate pronation, i.e.
to choose 9000 smaller radii on the inside of the foot. The profile
is swept forward along the length of the foot, parallel to the
sagilal axis, to define the surface of the sole in the middle of
the foot 9000 (FIG. 62, 63). To define the heel area of the Exo
foot 9000 the profile is rotated backwards around the axis of the
ankle. In the middle part of the foot 9000, approximately forward
from the ankle joint to the first toe joint, the surface of the
sole 904 then forms the surface segment of a cylinder or a
cylinder-like geometry on the left and right sides.
[0233] In the rear part of the foot 9000, approximately from the
ankle to the back, the sole surface on the left and right resembles
a surface segment of a ball or torus or the like. The front part of
the exo foot 9000 has the same cross-section at the transition from
the middle part of the foot as the middle part. The front part can
be flat but is preferably angled upwards to allow rolling. The
transition from the central to the front part can also be made in
the same way as the transition from the central to the rear part by
rotating/sweeping the surface profile around a transverse axis. The
distance of the transverse axis to the sole 904 is preferably much
greater for the front part than the distance from the sole 904 to
the ankle joint. This axis is preferably located near the lower leg
in order to achieve easy unrolling.
[0234] The advantage of the given foot 9000 is that now the foot
9000 of the exoskeleton (also robot or virtual avatar or virtual
machine) acts like a rolling bearing. When a step is taken and the
foot 9000 with the rounded heel area touches the ground, the foot
9000 rolls on the heel surface until the middle foot area touches
the ground. Until this time, the distance from ankle to floor is
kept practically constant, unless foot 9000 should roll strongly
from left to right at the same time. Even then, the change in
distance would be slow and gradual. This practically constant
distance when rolling also means that by rolling the foot 9000 a
firm base is created, the ankle joint, which does not change its
height and therefore does not work on the upper part of the body
when the user walks at constant speed (otherwise braking or
acceleration forces act in or against the direction of movement).
The rolling is therefore perceived as very fluid and soft, even if
the sole 904 of the foot 9000 is actually made of hard
material.
[0235] If the front part of the foot is shaped in the same way as
the rear part, but with a larger radius when rolling forward than
the heel, the same effect occurs and the foot does not do any work
on large parts of the body. However, the natural movement of the
knee and ankle requires a larger radius. It is also possible to
select a fixed ankle position where the center of this radius lies
in the knee joint. This allows extremely soft rolling even without
a movable ankle. The tangential transition of the profile radii
allows rolling to the left and right at any time.
[0236] The middle part of the foot 9000 is straight seen from the
side. This allows a stable standing and the user has a wide range
over which he can shift his center of gravity without becoming
unstable. This flat area can be reduced or increased by moving the
rotation axes of the profile forwards and backwards to influence
manoeuvrability. The transitional area to the front area of the
foot 9000 can also be moved forwards and backwards.
[0237] At the side there is no such straight area with the shown
Exo foot 9000. However, it can be added. Then the centres of the
circle segments in FIG. 63 would not lie on top of each other, but
would be offset to the left and right. At the bottom, the sole
would then have a straight section, which preferably merges
tangentially into the circle segments.
[0238] The outer edges of the foot 9000 are preferably rounded with
small radii to allow extreme postures and prevent injuries. The
sole 904 is preferably covered with rubber etc. and/or made of this
material. This improves traction and shock absorption when walking.
In particular, lateral rolling is also inhibited by an elastic,
damping material, which can be helpful in a cross profile without a
straight section to reduce the effort required to maintain balance
when standing on one foot. It is possible to use this type of foot
in exoskeletons, humanoid robots, virtual avatars or virtual
machines.
[0239] Stewart platforms, also known as hexapods, are also suitable
as motion platforms for exoskeletons in teleoperative (virtual or
real governor) systems. Stewart platforms generally have six linear
actuators or similar means attached to the floor or other base on
one side and to a work platform or working plane on the other.
[0240] FIGS. 64 and 65 show an example 4000 of a Stewart platform
according to the invention. FIG. 64 shows a perspective view and
FIG. 5 shows a front view of the Stewart platform 4000.
[0241] The Stewart 4000 platform has a fixed frame 303, also known
as the base. To this, a movable frame 302 is installed over a large
number of actuators 304a-304f, which are preferably designed as
linear actuators. An exoskeleton 300 is attached to this by means
of a mounting element 301. For the Stewart platform 4000 the
working platform is formed by the movable frame 302. The
exoskeleton 300 is positioned in the frame 302 by means of the
mounting element 301 in such a way that the user is centered
between the mounting points of the actuators 304a-304f at the
frame. The actuators 304a-304f are fixed to the movable frame 302
and to the fixed base 303 or to the floor or floor supports. The
usual basic arrangement for Stewart platforms with fixing points
offset from each other, as shown in FIG. 64, 65, is used. To make
it easier to swing the legs and arms forwards without colliding
with components of the body, it is advantageous to displace the
exoskeleton 300 slightly backwards. It is also advantageous if the
frame 302, with the user upright, is slightly tilted backwards, as
the user generally tends never to walk completely upright, thus
increasing the maximum forward tilting angles. The movable platform
according to the invention is equipped with long supports 305a,
305b and 305c. These supports 305a, 305b, 305c are essential to
maximize the working space of the motion simulator. They raise the
frame, relative to the user, and thus reduce potential for the user
to collide with the frame. They also allow the working platform, or
the supports themselves, to sink very low between the actuators and
still tilt, swivel, and accelerate linearly without colliding with
the 304a-304f actuators. This is further facilitated by the fact
that the distance between the 304a-304f actuators at base 303 and
their minimum length is so large that the 304a-304f actuators are
not yet fully retracted even if the above and lower attachment
points are practically in a plane parallel to the floor. This means
that translation and rotation can still be actuated even when the
working platform is in a low position. In order to enlarge the
rotatory working space of the motion simulator even further,
according to the invention it is provided that the exoskeleton 300
can also be rotated relative to the working platform 302 via
additional rotation actuators. For example, the fastening element
301 can be designed so that it can be rotated about its
longitudinal axis or its transverse axes or a combination of these.
A rotation unit can also be provided directly on the exoskeleton
300. In general, a gimbal suspension or a serial robot arm can also
be connected to the movable platform.
[0242] It is particularly advantageous to choose the first,
preferably circular element of a gimbal suspension as frame 302.
Then further elements of this suspension can preferably be mounted
inside this first element. Then the actuators of the Stewart
platform 4000 can be driven in such a way that they produce
rotations and/or translations, or also, for example, only
translations. In the latter case, the Stewart platform is used as a
pure translation unit, while the gimbal suspension acts as a pure
rotation unit. For the latter, the above-mentioned features
according to the invention can again be adopted. A Stewart platform
as a translation unit has the advantage of being very stiff and
strong because it is a parallel mechanism. However, the Stewart
platform can also generate rotations in addition to or in addition
to the held gimbal suspension. Rotation units on the movable
platform 302 can have any axis arrangement.
[0243] It can be advantageous to design the movable platform as a
frame, which places the cross connections between the fixing points
very high. This may for example resemble a hemisphere in strut
construction, or a dome, but with long struts 305 to the attachment
points with actuators 304. The cross struts can also be guided
diagonally upwards between the mounting points and thus no longer
lie in one plane, as in the illustrations. The base 303 is given in
FIG. 64, 65 as a frame. However, this frame can also be omitted and
the actuators can be fixed to the floor. The fixing points can also
stand on columns. The platform can then be kept very low without
the user running the risk of colliding with the floor. Then the
working area of the motion simulator is enlarged, but the space
requirement is increased.
[0244] Necessary joints for fixing the actuators to the platform
and the base are missing in FIGS. 64, 65 and are preferably
designed as Cardan shafts (U-joints).
[0245] The mounting element 301 is only indicated in the
illustrations. It is preferably located behind the exoskeleton 300,
but can be much stronger than in the illustrations. In particular,
it can be connected to the working platform at several points,
strutted, or even be part of the platform itself.
[0246] It is preferred to use telescopic linear actuators with more
than 2 coaxial elements (in figures one fixed and one movable
element=2 elements). These have a greater difference between
maximum and minimum length. Therefore they allow a much larger
working range. For example, telescopic ball screws or hydraulic
cylinders can be used. Particularly when the working platform lies
low or is angled steeply, this offers considerable advantages.
[0247] It may be useful to measure at the back of the exoskeleton
300, or at other points of the mechanism, the gravitational force
held and/or other forces and torques. This makes it easier to
control the exoskeleton 300 in teleoperative applications.
[0248] The advantages of the described motion simulator lie in its
ability to hold the user in such a way, for example in its middle,
that an enlarged usable working area can be used. The user can
easily be rotated around points inside or near him without the need
for particularly long actuator travel. By using the supports on the
movable working platform (or similar movable structures),
translation can still be generated even with simple linear
actuators in deep or far tilted/rotated spatial positions. The
tilting range, swivelling range, turning range etc., i.e. the space
of possible orientations is enlarged. These ranges are extended by
using one or more additional rotation axes to pivot the exoskeleton
300. If the Stewart platform is designed to contain a gimbal
suspension, arbitrary space positions can be assumed and classic
boundaries of Stewart platforms are overcome. Then the Stewart
platform serves as a very stiff and strong translation unit, but
can also represent rotations.
[0249] The described motion simulators, with Stewart platform or
translation unit and gimbal suspension, without exoskeleton, can
also be combined with other input and output units for computers.
Instead of the exoskeleton, an aircraft, helicopter or vehicle
cockpit can be mounted to control virtual or real means of
transport and to gain an improved impression of the forces acting
on them in remote control or simulation applications.
[0250] The innovations described here can be combined in a variety
of ways to achieve beneficial new properties in systems of
teleoperation, robotics, motion simulation and actuation.
[0251] Any one of the devices or processes described, any
combination of devices or processes or a combination of all devices
or processes can be realized.
[0252] In the following some advantageous combinations are
mentioned.
[0253] The described foot elements (FIG. 60-63 and description) for
humanoid robots, virtual or real machines and exoskeletons unfold
their full advantages especially with exoskeletons, robots or
virtual machines, which have a hip joint according to FIG. 1-26 and
above description. This hip joint allows better control of the legs
and feet, even in critical situations, and can therefore derive
maximum benefit from the additional degrees of freedom of the foot
elements.
[0254] The described exoskeletons (also in combination with the
described feet) can be combined with the described motion platforms
and their variations.
[0255] The described actuators can be used in exoskeletons,
remote-controlled humanoid robots and motion simulators in order to
achieve larger actuating angle ranges, larger torques, lower energy
consumption, smaller weight, back drivability, etc. in a small
space. The exoskeletons, remote-controlled humanoid robots and
motion simulators thus acquire properties that could not or only
with difficulty be achieved with other actuators. In particular,
the hip structure of the exoskeletons and humanoid robots described
benefits from the actuators described, as the third axis in
particular has to be able to perform a great deal of work and at
the same time has to have a very large range of actuating angles so
that the natural working range of the user is not significantly
restricted. The same applies to the fourth axis 96 of the knee,
although not to the same extent.
[0256] The described gimbal suspensions as motion simulator, their
elements or parts thereof can be combined with the described
exoskeletons, with improved hip joint, and the Stewart platform.
This allows to take advantage of the improved mobility and strength
of the exoskeleton, which would otherwise be constrained by limited
movement simulators. For example, fast jumping, running, running,
trampoline jumping, etc. are made possible by the exoskeletons
described, but a suitable motion simulator is also needed to fully
exploit this potential, which the motion simulators described
provide.
[0257] The same applies to methods and devices for reducing or
increasing the perceived force of gravity. They benefit from the
described hip joints, foot elements and motion simulators, alone or
in any combination. The methods and devices for reducing or
increasing the perceived gravity allow, for example, the use of
lighter exoskeletons when forces are reduced. However, in order to
be able to perform the faster movements and position changes that
are then possible, faster and better motion simulators, as
described, are needed or at least helpful. If forces are increased,
it is particularly important that every degree of freedom of the
foot is actuated.
[0258] Fully actuated hip joints with 3 effective degrees of
freedom and fully actuated feet, as described, allow heavier loads
to be carried by freely moving exoskeletons that a user controls
directly. If, instead, such robots are operated teleoperatively by
a remote user in an exoskeleton on a motion simulator, this user
benefits from the possibilities of gravity reduction described
above, and by using the described foot. This also applies to
virtual applications. The application of the described hips in
exoskeleton and robot further improves the applicability.
[0259] The Stewart platforms described can be combined with the
gimbal suspensions described. The actuators of the Stewart platform
then directly or indirectly carry a gimbal suspension. The
described innermost element 202, or several of them one behind the
other, can also be used to mount an exoskeleton (if necessary with
a mount such as 204) indirectly or directly to the mobile working
platform of a Stewart platform in order to enlarge the rotational
working space of the motion simulator.
[0260] It can be provided that an exoskeleton can be quickly
detached from the movement platform at the back. This exoskeleton
can then be used immediately as a mobile exoskeleton for force
enhancement or as a humanoid robot. It is then advantageous to
equip this exoskeleton with the described foot to allow easy
rolling and better control etc. Then this exoskeleton or robot etc.
can also have devices for gravity reduction or magnification.
[0261] When used as a "walking wheelchair", exoskeletons benefit
from any combination of hip joint, the described foot, and the
devices and procedures of gravity compensation or gravity
magnification. They allow handicapped, weak or paralyzed people to
move more naturally without having to carry their full weight with
their legs. Likewise, the perceived weight can be gradually
increased to achieve muscle growth or adaptation. For astronauts,
an impression of gravity can also be achieved, which otherwise
would not exist, but here can serve to reduce muscle breakdown.
[0262] Each of the described innovations, including the
combinations described above, each combination of innovations or a
combination of all innovations can be realized.
REFERENCE CHARACTER LIST
[0263] 80a element 1, first element, exo hip or exo back plate
[0264] 80b axle mounting region (mounting element) of 80a [0265] 81
shaft of axis 1 [0266] 82 exo hip joint 1, element 2, second
element [0267] 82b exo hip joint 1b, element 2b [0268] 82c exo hip
joint 1c, element 2c [0269] 83 shaft of axis 2 [0270] 84 exo hip
joint 2, element 3, third element [0271] 85 shaft of axis 3 [0272]
86 element 4, fourth element, exo thigh [0273] 87 shaft of axis 4
[0274] 88 element 5, fifth element, exo-lower leg [0275] 89 shaft
of axis 5 [0276] 90 element 5, sixth element, exo-foot [0277] 91
centre of the hip joint [0278] 92 axis parallel to the sagital axis
through the center of the hip joint [0279] 93 axis 1, first axis
[0280] 94 axis 2, second axis [0281] 94b axis 2b [0282] 94b axis 2c
[0283] 95 axis 3, third axis [0284] 96 4th axis 4th axis [0285] 97
Axis 5, fifth axis [0286] 101 driven shaft/driven axle [0287] 102
deflection shank, idler shank [0288] 103 fixed shaft/fixed axle
[0289] 104a bearing, front, driven axle [0290] 104b bearing, rear,
driven axle [0291] 104c bearing, central, driven axis [0292] 105a
bearing, front, free running axle [0293] 105b bearing, rear, free
running axle [0294] 106a front base plate [0295] 106b rear base
plate [0296] 107 base frame [0297] 108 driven, front sprocket
[0298] 109 free-running front sprocket [0299] 110 front chain
[0300] 111 driven, rear sprocket [0301] 112 free running, rear
chain wheel [0302] 113 rear chain [0303] 114 ball screw [0304] 115
ball screw bearing A [0305] 116 ball screw bearing B [0306] 117
spindle nut, ball nut, nut [0307] 118 connecting block [0308] 118b
connecting block with abutment for spring element [0309] 119 linear
guide rail, rail [0310] 120 linear guide carriage [0311] 121 linear
guide support [0312] 121b linear Guide Support combined with Base
[0313] 122 shaft coupling [0314] 123 motor frame [0315] 124 motor
[0316] 125a bearing, front, for free-running sprocket [0317] 125b
bearing, rear, for free-running chain sprocket [0318] 126 spacers
[0319] 127 spring element [0320] 128 chain-spring connection
element [0321] 129 bearing for free-running sprocket [0322] 130
bearings for axles [0323] 200 element A, first rotation element
[0324] 201 element B, second rotation element [0325] 202 element C,
third rotation element [0326] 203 exoskeleton with back mount
[0327] 204 back mount [0328] 205 axis A, first axis of rotation
[0329] 206 axis B, second rotation axis [0330] 207 C axis, third
axis of rotation [0331] 208 D axis, fourth rotation axis [0332] 210
translation unit [0333] 211 rotation unit [0334] 212 element angle
A [0335] 213 element angle B [0336] 214 element angle C [0337] 220
intersection of 205-208 [0338] 250 first linear actuator [0339] 252
second linear actuator [0340] 254 third linear actuator [0341] 300
exoskeleton [0342] 301 mounting element [0343] 302 movable
frame/working platform [0344] 303 fixed frame/base [0345] 304
actuators [0346] 304a-f linear actuators [0347] 305 supports [0348]
305a-c individual supports [0349] 902 shaft [0350] 904 sole [0351]
910 axis through 902 [0352] 1000-1003 exoskeleton [0353] 2000-2009
actuators [0354] 3000 motion simulator [0355] 4000 stewart platform
[0356] 9000 exo foot [0357] X driven component
* * * * *
References