U.S. patent application number 10/842624 was filed with the patent office on 2005-11-17 for ground-based haptic interface comprising at least two decoupled rotary finger actuators.
This patent application is currently assigned to UNIVERSITE DES SCIENCES ET TECHNOLOGIES DE LILLE. Invention is credited to Casiez, Gery, Chaillou, Christophe, Plenacoste, Patricia, Semail, Betty.
Application Number | 20050257150 10/842624 |
Document ID | / |
Family ID | 35310771 |
Filed Date | 2005-11-17 |
United States Patent
Application |
20050257150 |
Kind Code |
A1 |
Casiez, Gery ; et
al. |
November 17, 2005 |
Ground-based haptic interface comprising at least two decoupled
rotary finger actuators
Abstract
The present invention concerns a ground-based haptic interface
equipped with at least two decoupled rotary finger actuators
adapted to be manipulated with the fingertips of a single hand of a
user. For each finger actuator, means are included for measuring
the angular position of the actuator or a for measuring the torque
applied on the axis of rotation of the actuator. Each rotary finger
actuator is associated with a control motor adapted to apply, on
the axis of rotation of the actuator, a torque that is a function
of the angular position of the actuator, or that controls the
rotational position of the axis of rotation of the actuator as a
function of the torque applied on this axis. The haptic interface
can be used as a peripheral of a computer, for example, for
interacting with a virtual environment. It can also be applied to
the control or manipulation of real objects by being coupled, for
example, with a robot or a manipulating arm. The interface also can
be telemanipulated.
Inventors: |
Casiez, Gery; (Honnechy,
FR) ; Chaillou, Christophe; (Lille, FR) ;
Semail, Betty; (Lille, FR) ; Plenacoste,
Patricia; (Lille, FR) |
Correspondence
Address: |
MILES & STOCKBRIDGE PC
1751 PINNACLE DRIVE
SUITE 500
MCLEAN
VA
22102-3833
US
|
Assignee: |
UNIVERSITE DES SCIENCES ET
TECHNOLOGIES DE LILLE
Villeneuve d'Ascq
FR
CENTRE NATIONAL DE RECHERCHE SCIENTIFIQUE
Paris
FR
|
Family ID: |
35310771 |
Appl. No.: |
10/842624 |
Filed: |
May 11, 2004 |
Current U.S.
Class: |
715/701 |
Current CPC
Class: |
G06F 3/016 20130101 |
Class at
Publication: |
715/701 |
International
Class: |
G06F 017/00 |
Claims
1-12. (canceled)
13. Ground-based haptic interface (1), comprising a case and at
least two decoupled rotary finger actuators operatively disposed
within the case, said case having at least two openings, said
actuators being disposed to extend partially through the openings
in the case so as to be capable of manipulation with the fingertips
of a single hand.
14. An interface according to claim 13 characterized in that a
first actuator and its corresponding opening is positioned such
that the first actuator and its corresponding opening is positioned
such that the second actuator can be manipulated with the thumb of
the user's hand, and a second actuator can be manipulated with the
index finger of the user's hand.
15. An interface according to claim 14 characterized in that the
axis of rotation of the first actuator associated with the user's
thumb is oriented transverse to the axis of rotation of the second
actuator that can be manipulated with the user's index finger.
16. An interface according to claim 15 characterized in that it
includes at least a third decoupled rotary finger actuator.
17. An interface according to claim 13 characterized in that it
includes, for each finger actuator, means associated with the
actuator or a torque applied on the axis of rotation of the
actuator for measuring the angular position of the associated
actuator.
18. An interface according to claim 14 characterized in that it
includes, for each finger actuator, means associated with the
actuator or a torque applied on the axis of rotation of the
actuator for measuring the angular position of the associated
actuator.
19. An interface according to claim 15 characterized in that it
includes, for each finger actuator, means associated with the
actuator or a torque applied on the axis of rotation of the
actuator for measuring the angular position of the associated
actuator.
20. An interface according to claim 16 characterized in that it
includes, for each finger actuator, means associated with the
actuator or a torque applied on the axis of rotation of the
actuator for measuring the angular position of the associated
actuator.
21. An interface according to claim 13 characterized in that the
axis of rotation of each actuator is motorized.
22. An interface according to claim 14 characterized in that the
axis of rotation of each actuator is motorized.
23. An interface according to claim 15 characterized in that the
axis of rotation of each actuator is motorized.
24. An interface according to claim 16 characterized in that the
axis of rotation of each actuator is motorized.
25. An interface according to claim 13 characterized in that it
includes, for each rotary finger actuator associated control means
for applying a torque on an axis of rotation of the associated
actuator.
26. An interface according to claim 14 characterized in that it
includes, for each rotary finger actuator associated control means
for applying a torque on an axis of rotation of the associated
actuator.
27. An interface according to claim 15 characterized in that it
includes, for each rotary finger actuator associated control means
for applying a torque on an axis of rotation of the associated
actuator.
28. An interface according to claim 16 characterized in that it
includes, for each rotary finger actuator associated control means
for applying a torque on an axis of rotation of the associated
actuator.
29. An interface according to claim 25 characterized in that the
control means associated with each actuator is adapted to apply on
the axis of rotation of the actuator a torque that is a function of
the angular position of the actuator.
30. An interface according to claim 13 characterized in that it
includes, for each rotary finger actuator, an associated control
means for controlling the position of an axis of rotation of the
actuator.
31. An interface according to claim 14 characterized in that it
includes, for each rotary finger actuator, an associated control
means for controlling the position of an axis of rotation of the
actuator.
32. An interface according to claim 15 characterized in that it
includes, for each rotary finger actuator, an associated control
means for controlling the position of an axis of rotation of the
actuator.
33. An interface according to claim 16 characterized in that it
includes, for each rotary finger actuator, an associated control
means for controlling the position of an axis of rotation of the
actuator.
34. An interface according to claim 30 characterized in that the
control means associated with each actuator is adapted to
rotationally position the axis of rotation of the actuator as a
function of the torque applied on the axis of rotation of the
actuator.
35. An interface according to claim 34 characterized in that the
control means associated with each finger actuator include a motor
(M).
36. An interface according to claim 13 characterized in that the
case includes a contact surface that is ergonomically adapted to
the palm of the hand.
37. An interface according to claim 14 characterized in that the
case includes a contact surface that is ergonomically adapted to
the palm of the hand.
38. An interface according to claim 15 characterized in that the
case includes a contact surface that is ergonomically adapted to
the palm of the hand.
39. An interface according to claim 16 characterized in that the
case includes a contact surface that is ergonomically adapted to
the palm of the hand.
Description
[0001] The present invention concerns a novel "ground-based" haptic
interface comprising at least two finger actuators, i.e. actuators
that can be manipulated with the fingertips of one hand. This
interface can be used as a peripheral for a computer or equivalent
device, and in this case allows a user to interact with a virtual
environment and in particular to manipulate or control virtual
objects. The invention is also applicable to the control or
manipulation of real objects, since the interface of the invention
can be coupled with any type of machine, for example including but
not limited to a robot, a manipulating arm, etc.; the interface of
the invention can also be used in the field of
telemanipulation.
[0002] The term "haptic" interface commonly designates any
man-machine interface that allows force feedback and/or tactile
feedback for the user.
[0003] The haptic interfaces that can be manipulated with a single
hand can be classified into two fundamentally different categories.
The first category includes the "ground-based>> haptic
interfaces. In the present text, <<ground-based>>
haptic interface designates any haptic interface that generally
comprises a structure that is placed on a surface (floor, desk,
table, etc.) and that is designed to be manipulated with a single
hand. The second category includes the so-called "man-based"
interfaces, which are constituted by portable devices designed to
be attached to the user. The most common examples of
<<man-based >> interfaces are constituted by haptic
devices that are attached to one hand, such as force feedback
gloves or the haptic devices described, for example, in the
publications WO-A-0207143 and WO-A-9851451.
[0004] The invention belongs to the field of the haptic interfaces
in the first category mentioned above, i.e. "ground based."
[0005] In this field, a first example of a known "ground-based"
haptic interface is described in the patent U.S. Pat. No.
6,417,638. This interface is a haptic device with six degrees of
freedom (only three of which are motorized) and essentially
includes an arm articulated in relation to a fixed base and
manipulable by a single hand. This type of haptic device has a very
sophisticated design and is therefore very expensive to produce;
moreover, this haptic device is bulky and is generally used with
the forearm in the air, which makes using the device tiring from a
muscular point of view.
[0006] A second example of a known "ground-based" haptic interface
is described in particular in international patent application
WO-A-9628777. The interface described in this publication is used
as a 3D computer peripheral and includes a single tactile-feedback
actuator that can be manipulated with the fingertips. More
particularly, this single actuator is in the form of a ball that
can be manipulated by a user. The ball's rotation on itself allows
control on two axes X and Y, while control on a third axis Z
transverse to the plane (X,Y) is obtained by a vertical
translational movement of the ball. Advantageously, this type of
<<ground-based>> interface with a single actuator
manipulable by the fingertips is not very bulky and can be used
with the hand resting at least partially on a surface, which makes
it less tiring to use from a muscular point of view, compared to
the example of "ground-based" interfaces of the type described in
the aforementioned patent U.S. Pat. No. 6,417,638.
[0007] The subject of the invention is a novel haptic interface
that is ground-based and can be manipulated by the fingertips of a
single hand.
[0008] The <<ground-based>> haptic interface of the
invention is characterized in that it is equipped with at least two
decoupled rotary finger actuators that can be manipulated with the
fingertips of a single hand.
[0009] Like the haptic interface described in the publication
WO-A-9628777, the haptic interface of the invention is not very
bulky and can be used with the hand resting at least partially on a
surface, which advantageously makes the interface less tiring to
use from a muscular point of view. The decoupling of the finger
actuators of the interface of the invention advantageously allows a
decoupling of each degree of freedom, and thus a better
manipulation of the virtual or real objects associated with the
interface, compared to the ground-based haptic interface with a
single actuator described in the publication WO-A-9628777.
Likewise, this decoupling advantageously makes it possible to
simplify the mechanical architecture of the interface compared to
the mechanical architectures of interfaces with only one actuator,
particularly when the interface is equipped with motors or the like
for simulating a force feedback and/or a tactile feedback in each
degree of freedom. Finally, it is advantageous that the haptic
interface of the invention is designed to be manipulated with the
fingertips of the hand, since that is the part of the hand that is
most sensitive to touch, and thus the part of the hand most likely
to sense tactile and/or force feedback.
[0010] In a preferred variant of embodiment, the interface
includes, for each rotary finger actuator, control means that are
designed to apply, on the axis of rotation of the actuator, a
torque that is a function of the angular position of the
actuator.
[0011] Other characteristics and advantages of the invention will
emerge more clearly below in light of the following detailed
description of a preferred exemplary embodiment of a haptic
interface of the invention, which description is given as a
nonlimiting example in reference to the attached drawings in
which:
[0012] FIG. 1 is a representation in perspective of a ground-based
interface of the invention that includes three rotary actuator
levers that can be manipulated simultaneously by means of the
thumb, the index and the ring finger of one hand,
[0013] FIGS. 2 and 3 illustrate two exemplary embodiments of a
finger actuator,
[0014] FIG. 4 represents in perspective an assembled lever,
[0015] FIG. 5 represents in perspective the lever of FIG. 4,
without its angular position sensor,
[0016] FIG. 6 is an exploded view of the lever of FIG. 4,
[0017] FIG. 7 represents the interface of FIG. 1 without its cover,
making it possible to better illustrate the positioning and the
mounting of the levers,
[0018] and FIG. 8 represents an exemplary control loop of the motor
associated with each actuator, which makes it possible to apply on
the axis of rotation of the actuator a torque that is a function of
the measured angular position of the actuator.
[0019] FIG. 1 represents a preferred variant of embodiment of a
haptic interface of the invention. This interface 1 comprises a
fixed structure (2a, 2b) which is designed to be placed on a
surface such as, for example, a desk or a table, and to which are
adapted three force-feedback finger levers 4, 5 and 6, each
respectively comprising a rotary finger actuator 4a, 5a and 6a.
[0020] The three finger actuators 4a, 5a and 6a are rotating parts
and are decoupled from one another. Each rotary finger actuator 4a,
5a or 6a is designed to be actuated by a finger of one hand. Each
rotary actuator of a lever 4, 5 and 6 corresponds to a degree of
freedom.
[0021] FIGS. 2 and 3 represent two non-exhaustive examples of
finger actuators, which are distinguished from one another by the
contour of their contact surface 5C with the finger. This contour
of the contact surface 5C of each actuator is designed
ergonomically in order to prevent the actuator from slipping from
the finger.
[0022] In the example illustrated in FIG. 1, which does not limit
the invention, the aforementioned fixed structure (2a, 2b) forms a
case constituted by a base 2a topped by an attached cover 2b.
Preferably, the external surface 2d of the cover 2b, which is
designed to come into contact with the palm of the hand, is shaped
so as to be ergonomically adapted to the hand. The cover 2b also
includes three openings 2c, the rotary finger actuators 4a, 5a, 6a
partially passing through the respective openings 2c of the cover,
the remaining part of the structure of each lever being housed
inside the case formed by the base 2a and the cover 2b.
[0023] FIGS. 4, 5 and 6 represent a particular example of the
structure of a lever. In this example, the lever comprises:
[0024] a base S onto which are mounted two parallel supports S1 and
S2,
[0025] a motor M, for example a DC motor, which is attached to the
support S2 and whose output shaft AM passes through the support S2
and supports a pulley P,
[0026] a hollow rotating rod T mounted freely on the two supports
S1 and S2 by means of bearings P1 and P2, the rod running above and
parallel to the output shaft AM of the motor M,
[0027] the finger actuator 4a (5a; 6a), which is slid onto the rod
T, and which is attached to this rod (T) by means of a screw or the
like (non represented) passed through a through hole T1 of the
actuator; the actuator 4a and rod T assembly thus rotates, on the
axis of the rod T, relative to the supports S1 and S2,
[0028] a transmission cable (CT) wound around the pulley P and
passed through the actuator 4a (FIG. 5/through hole T2),
[0029] a means C for measuring the angular position of the actuator
that is mounted on the end of rod T.
[0030] Preferably, the initial tension of the cable CT is
adjustable by means of a tightening screw (not represented) or any
other equivalent means passed through the through hole T3 (FIG.
5).
[0031] In operation, the measuring means C delivers information
characteristic of the angular position of the actuator 4a (5a or
6a). The measuring means C can be embodied by means of any device
that makes it possible to measure an angle; it can be for example a
potentiometer, a Hall effect sensor, an optical encoder, etc.
[0032] The motor M makes it possible to apply a torque on the axis
of rotation of the finger actuator, thereby returning a force
feedback to the actuator, as will be seen more clearly below.
[0033] FIG. 7 represents the interface 1 without the cover 2b, said
FIG. 7 making it easier to visualize the mounting and the
positioning of the various levers. In the embodiment of the
attached figures, the actuators 4a and 6a of the levers 4 and 6 are
identical to the actuator of FIG. 2, while the actuator 5a of the
lever 5 is identical to the actuator of FIG. 3. This does not limit
the invention. In another embodiment, the actuators could all be
identical, or conversely, all different.
[0034] The interface is used by placing the wrist in contact with
the surface on which the interface is placed, bringing the palm of
the hand in contact with the external surface 2d of the cover 2b,
and manipulating each actuator 4a, 5a, 6a by rotating it with the
fingertips, each finger actuator being manipulable by a single
finger of the hand. In another variant of embodiment of the
invention (not illustrated), it is conceivable to design an
interface whose structure and actuators are designed so that the
interface is used with the hand no longer oriented approximately
horizontally as in the variant of FIG. 1, but for example with the
hand oriented approximately vertically and resting on its edge.
[0035] According to a preferred characteristic of the invention,
the finger actuators 4a, 5a and 6a are disposed relative to one
another in such a way that they can be manipulated simultaneously,
respectively by means of the thumb, index finger and ring finger of
the same hand. In the variant of FIG. 1, the interface is thus
adapted for a right-hander, it being understood that one skilled in
the art would immediately reverse the positions of the actuators
4a, 5a and 6a in order to design a left-handed interface.
[0036] More particularly, the axes of rotation of the actuators 4a,
5a 6a each have an orientation adapted to the movement of the
fingers that manipulate them. Thus, if we consider the interface to
have an axis A called the main axis (see FIG. 7) which, during the
use of the interface, is approximately parallel to the axis of the
user's forearm, the axis of rotation 4b of the actuator 4a, which
is designed to be manipulated by the thumb, forms with said main
axis A an angle .beta. on the order of 45.degree. so as to maintain
the natural angular position of the thumb of the hand relative to
the other fingers; the axes of rotation 5b and 6b of the other two
actuators 5a and 6a are oriented approximately perpendicular to
said main axis A. Thus, the axis of rotation 4b of the actuator 4a
is oriented transverse to the axes of rotation 5b and 6b of the
other two actuators 5a and 6a; preferably, the axis 4b and the axis
5b (or respectively 6b) form between them an angle .alpha. (FIG. 7)
that is slightly larger than 90.degree.. In operation, the haptic
interface 1 just described is for example connected to a real-time
system by means of an input-output card, and said real-time system
is connected to a computer running a 3D virtual environment,
represented graphically on the screen of the computer. The
real-time system primarily makes it possible to control the force
feedback to each finger actuator, as will be explained below in
reference to FIG. 8. The real-time system also provides the
computer with information on the angular position of each actuator,
which computer is programmed to transform the angular position
information into graphical actions in the 3D graphic
environment.
[0037] To give a non-exhaustive example, the interface 1 can be
used to manipulate virtual objects in a 3D graphic environment,
each actuator being associated with a degree of freedom of a
movement displayed on the screen. Generally, though not
exhaustively, each actuator is for example associated with a
translational or rotating movement that can be displayed on the
screen.
[0038] For example, in translation mode, in order to make the use
of the interface intuitive, the rotating movement of the actuator
4a associated with the thumb corresponds to a movement of the
manipulated object in the direction of the width of the screen; the
rotating movement of the actuator 5a associated with the index
finger corresponds to a movement of the manipulated object in the
direction of the depth of the screen; and the rotating movement of
the actuator 6a associated with the ring finger corresponds to a
movement of the manipulated object in the direction of the height
of the screen.
[0039] In rotating mode, the finger actuators are used for example
to rotate the virtual objects around orthogonal axes.
[0040] Movements that are more complex than the simple translation
or rotation of an object can also be associated with each finger
actuator.
[0041] No matter what the aforementioned operating mode
(translation, rotation, etc.) the interface 1 can advantageously be
used in an isotonic or isometric mode. The isotonic mode
corresponds to a positional control of the objects to be
manipulated; an angular position of each finger actuator
corresponds to a position on the screen of the manipulated object.
The isometric mode corresponds to a speed control of the objects to
be manipulated; each actuator is initially in a neutral position,
and when the user moves the finger actuator, a force proportional
to the movement is exerted on his finger, by means of an adapted
torque applied by the motor M of the lever; each force is
associated with a speed.
[0042] In a sophisticated variant of embodiment, the interface 1
can be equipped, for each actuator, with a manual operating mode
(translation/rotation/etc.) selector, as well as a manual
isotonic/isometric mode selector, in order to allow the user to
configure the operating mode of each actuator adapted to the
application controlled by means of the man-machine interface.
[0043] FIG. 8 represents the control loop of a lever that makes it
possible to simulate a force feedback to the actuator of the lever.
It is important to emphasize that the interface 1 includes three
decoupled levers. Consequently, the control of the interface
actually includes three parallel control loops like those in FIG. 8
(one control loop per lever).
[0044] In reference to FIG. 8, each control loop is an impedance
control loop:
[0045] having as input to the real-time system 9, the measurements
(p.sub.i) of the angular position of the finger actuator, which
measurements (p.sub.i) are output by the measurement means C of the
lever, in the form of an analog electrical signal 7 that is
converted by an analog-to-digital converter 8,
[0046] and having as output from the real-time system 9 a digital
set point (Cons) (signal 10/FIG. 8) that is converted to an analog
signal by means of the digital-to-analog converter 11, then
transformed into a control signal 13 for the motor M by means of an
amplification stage 12.
[0047] The set point (Cons) calculated by the real-time system 9 as
a function of the measured angular positions (p.sub.i) of the
actuator of the lever makes it possible to simulate for the user a
force feedback to the actuator that is a function of the command
law programmed (Cons=f(pi)). Thus, the control system of each lever
makes it possible, by means of the motor M, to apply a torque on
the axis of rotation of the actuator that is a function of the
angular position of the actuator, the value of the torque depending
on the command law programmed.
[0048] For example, when a finger actuator is used in isotonic
mode, the control system of the lever makes it possible to simulate
in the actuator the weight of the objects manipulated, their
friction, the encountering of obstacles, etc. It is also possible
to simulate a notching effect in the rotation of the actuator. When
a finger actuator is used in isometric mode, the torque applied on
the axis of the finger actuator is proportional to the angular
position of the finger actuator.
[0049] The invention is not limited to the particular variant of
embodiment just described in reference to the attached figures. In
particular, though this is not exhaustive, it is conceivable to
produce a simplified ground-based haptic interface comprising only
two decoupled rotary finger actuators, or conversely a more
sophisticated interface comprising more than three decoupled rotary
finger actuators. The control means associated with each actuator
in order to apply a torque on the axis of rotation of the actuator
are not necessarily motorized, but can, for example in a less
sophisticated variant of embodiment, be purely mechanical and exist
in the form of an elastic return means like a spring or the
equivalent.
[0050] The control of each actuator of the haptic interface of the
invention is not necessarily implemented by means of impedance
control loops, but can also be implemented by means of admittance
control loops. In the case of an admittance control loop, the
angular position sensor C described above is replaced by a torque
sensor that makes it possible to measure the torque applied by the
user on the axis of rotation of the actuator; the motor M is
positionally controlled so as to bring the actuator to an angular
position that is a function of the torque measured by the
sensor.
[0051] The interface 1 of the attached figures can also be used to
manipulate real objects such as a robot, manipulating arm, etc.
* * * * *