U.S. patent number 3,776,058 [Application Number 05/254,126] was granted by the patent office on 1973-12-04 for multi-axis hand controller.
This patent grant is currently assigned to The United States of America as represented by the Secretary of the Navy. Invention is credited to Dana French.
United States Patent |
3,776,058 |
French |
December 4, 1973 |
MULTI-AXIS HAND CONTROLLER
Abstract
A precision mechanical centering device is provided in which a
single spr controls the return of two oppositely formed spring
plates to a positive stop in each of the three axes of motion. Null
adjustment is made by separating the tines of a tuning fork mounted
on the same axis as each pair of spring plates until the tines
contact the end surface of the spring plates. These end surfaces
are positioned apart and prevented from closing by a tab of
appreciable thickness which is either securely attached to or an
integral part of a centrally located ground block.
Inventors: |
French; Dana (Belmont, MA) |
Assignee: |
The United States of America as
represented by the Secretary of the Navy (Washington,
DC)
|
Family
ID: |
22963025 |
Appl.
No.: |
05/254,126 |
Filed: |
May 17, 1972 |
Current U.S.
Class: |
74/471XY |
Current CPC
Class: |
G05G
9/00 (20130101); B63G 8/14 (20130101); G05G
9/047 (20130101); G05G 2009/04718 (20130101); G05G
2009/04748 (20130101); G05G 2009/04781 (20130101); Y10T
74/20201 (20150115) |
Current International
Class: |
B63G
8/00 (20060101); B63G 8/14 (20060101); B64C
13/04 (20060101); B64C 13/00 (20060101); G05G
9/00 (20060101); G05G 9/047 (20060101); G05g
009/04 () |
Field of
Search: |
;74/471XY,471
;200/6A |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kaufman; Milton
Claims
What is claimed is:
1. A panel mounted hand controller for providing three-axis control
of a free-moving object through selective movement of a control
stick which is restricted to angular displacements of .+-.
15.degree. and a dead zone of 1/10.degree. comprising:
a housing and means rotatably supported therein for mounting said
control stick and permitting omnidirectional movement and rotation
thereof relative to the three axes of motion,
said housing and said means having openings about said control
stick to accommodate the desired limit of movement thereof,
said means rotatable about one axis of motion with respect to said
housing;
a yoke rotatably mounted on said means and orthogonally disposed
with respect to said one axis of motion for providing rotation
about a second axis of motion;
said control stick rotatably received in and extending through said
yoke for rotation about the third axis of motion;
a pair of matched plates of opposite hand mounted for rotation
about each of said axes of motion;
said plates each having parallel-disposed extensions;
a mechanical stop interposed between respective pairs of said
extensions for establishing a neutral position thereof and a
resilient means connecting said respective pairs of extensions for
urging each extension against its respective stop; and
signal generating means coupled about each of said axes of motion
for generating signals representative of relative motion of said
control stick, said yoke, and said rotatably supported means about
said axes with respect to, respectively, said yoke, said rotatably
supported means, and said housing,
whereby desired movement of said object may be caused by selected
movement of said control stick about one, two or all three of the
axes of motion.
2. The device as defined in claim 1 wherein said rotatably
supported means is a receptacle within which the three axes of
motion intersect,
said control stick rotatably mounted in said receptacle opposite
the opening for accommodating movement of said control stick;
and
a flexible section in said control stick encompassing the
intersection of the three axes of motion to permit flexing of said
control stick during rotation of said yoke about the pitch
axis.
3. The device as defined in claim 2 wherein the surface of said
housing adjacent the opening therein has a spherical curvature;
a spherical cover plate adjustably mounted on said control stick
and adapted to mate with said spherical surface of said housing;
and
means on said control stick for forcing said cover plate against
said housing at any position of said control stick so that said
control stick may be locked in any position against the forces of
said resilient means.
4. The device as defined in claim 3 wherein the axis of motion
which is colinear with the longitudinal axis of said control stick
is the yaw axis, the axis about which said yoke rotates is the
pitch axis, and the axis about which said receptacle rotates is the
roll axis;
cylindrical shaft sections supporting said receptacle in said
housing and said yoke on said receptacle,
said shaft sections selectively positioned along said pitch and
roll axes and respective pairs of said matched plates mounted
thereon and on said control stick; and
strap means affixed to said housing for supporting said receptacle
for rotation about said pitch axis;
said strap means and said yoke including pairs of tines positioned
substantially in register with respective ones of said mechanical
stops and means for adjusting said tines so as to be in register
with said mechanical stops,
whereby movement of said control stick causing motion in either
direction about any of said axes of motion will displace respective
ones of said pairs of plates from its respective mechanical stop
against the tensile force of the same respective resilient means
thereby assuring the same corrective force for returning the
displaced plates to the neutral or zero position in contact with
the respective mechanical stop.
5. In a system for providing three-axis control of an object
through a panel mounted hand control member restricted to angular
displacements of .+-. 15.degree. and a dead zone of 1/10.degree.
the combination of:
said control member aligned with and rotatable about one of the
three axes of motion and means coupled to said control member and
rotatable about each of the remaining axes of motion;
a pair of matched plates of opposite hand mounted for rotation
about said axes in response to movement of said control member and
said means coupled thereto;
a resilient member connecting and common to each pair of
plates;
means for arresting said plates under tension of said resilient
member at a null position when said control member is in the
neutral position,
said plates spaced apart in the null position by said arresting
means so that movement of said control member from the neutral
position in either direction about any or all of said axes of
motion causes rotary displacement of only one of said plates in
each pair at a time against the tensile force of said common
resilient member with said arresting means preventing movement of
the other plate of the pair,
said control member returned to the neutral position upon removal
of the disturbing torque by the said one displaced plate or
plates.
6. The system as defined in claim 5 and further including signal
generating means mounted in fixed relation to each of said axes for
generating signals representative of relative motion of said ones
of said pairs of plates about said axes,
whereby desired movement of said object may be caused by selected
movement of said control member about one, two or all three of the
axes of motion.
7. The system as defined in claim 6 and further including
positioning means on said control member and on said coupled
means,
said positioning means extending between respective pairs of said
plates and in substantial alignment with and close proximity to
said arresting means; and
means for precisely aligning said positioning means with said
arresting means.
8. The system as defined in claim 7 and further including means for
locking said control member in any position to which it may be
moved.
9. A hand controller adapted to be panel mounted for providing
three axis hand control of a freely movable object through
selective movement of a control stick which is restricted to
angular displacement of .+-. 15.degree. and a dead zone of
1/10.degree. comprising:
a housing, a ground block and means for rotatably suspending said
ground block in said housing,
said block rotatable about one of the axes of motion with respect
to said suspending means;
a yoke rotatably mounted on said block;
said yoke rotatable about a second axis of motion which is
orthogonal to said one axis of motion;
a control stick extending through said housing, said yoke and said
block and pivotally mounted in said block;
said housing and said block having openings about said control
stick so as to permit movement thereof in any direction;
means mounted on said yoke and said suspending means for
resiliently resisting and for arresting rotary movement of said
control stick with respect to said yoke, said yoke with respect to
said block, and said block with respect to said housing; and
motion detecting and relaying means mounted adjacent to said rotary
movement resisting means to transmit signals generated by movement
of said control stick to said movable object.
10. The device as defined in claim 9 wherein the surface of said
housing adjacent the opening therein has a spherical curvature;
and
a spherical cover plate adjustably mounted on said control stick
and adapted to mate with said spherical surface of said housing;
and
means on said control stick for forcing said cover plate against
said housing at any position of said control stick so that said
control stick may be locked in any position.
11. The device as defined in claim 10 wherein said rotary movement
resisting means are disposed about each of the three axes of
motion;
said rotary movement resisting means each including a pair of
oppositely formed matched plates and a common resilient means
connecting each pair of plates,
said pair of plates spaced apart in the neutral position by
protruding portions of said ground block and said yoke,
said resilient means so positioned as to be elongated in the
direction of movement of said control stick, the ones of said pairs
of plates not rotated by motion of said control stick abutting said
protruding portions and providing a precise reference with respect
to the zero or neutral position of said control stick.
12. The device as defined in claim 11 wherein said means for
arresting rotary movement are ground bosses positioned on said
ground block and said yoke;
adjusting means secured to said means for suspending said ground
block and said yoke opposite respective ones of said ground
bosses,
said adjusting means narrower than the width of said ground bosses
to permit insertion of the adjusting means between the rotary
movement resisting means,
said adjusting means adjustable to the precise width of said ground
bosses,
said precise adjustment, said gound bosses and said common
resilient means providing a dead zone of 1/10.degree. or less in
the operation of said hand controller.
13. The method of controlling the omnidirectional movement of an
object by a panel-mounted hand controller through selective
movement of a control stick which is restricted to angular
displacements of .+-. 15.degree. and a dead zone of 1/10.degree.
comprising:
rotating a reference component about one axis of motion with
respect to the hand controller housing;
rotating a second component about a second axis of motion with
respect to the reference component;
rotating the control stick about a third axis of motion with
respect to the second component;
providing a stationary reference to rotation about the three axes
of motion by ground components positioned adjacent to each axis of
motion;
restraining both clockwise and counterclockwise rotation about each
axis by a single resilient component common to oppositely
configured motion transfer means;
anchoring the control stick in the reference component; and
providing a flexible section in the control stick in the region of
the intersection of the three axes of motion to permit rotation of
the second component about the axis which passes therethrough.
14. The method as defined in claim 13 wherein control about two of
the axes of motion is effected by coupling together the control
stick and the second component,
the flexible section in the control stick permitting rotary
movement of the second component with respect to the reference
component.
15. The method as defined in claim 14 and further including
generating signals representative of relative motion of the control
stick, second component and reference component with respect to the
second component, reference component and housing for control of
movement of said object.
16. The method as defined in claim 15 wherein motion in yaw of said
object is obtained by rotating the control stick with respect to
both the second component and the reference component, motion in
pitch of said object is obtained by rotating the second component
with respect to the reference component and motion in roll of said
object is obtained by rotating the reference component with respect
to the housing.
Description
This invention concerns precision mechanical centering means, and
more particularly, apparatus for achieving a substantially absolute
null position about one or more axes in gimbaled or non-gimbaled
systems.
In controlling moving objects such as land or water vehicles or
even aircraft, it is desirable that control about two or more axes
be concentrated in a single hand-gripped control element. In an
aircraft, for example, such a control element would be a stick
through which pitch, yaw and roll may be controlled in lieu of the
present methods where both foot and hand-operated controls are
utilized. Such a hand control unit, to provide the precise control
necessary, must have a substantially absolute null position so that
there is no play in the system which would cause a lag in
transmitting controls from the operator to the various mechanisms
connected to the hand controller. Since a single stick control is
the optimum means for achieving a substantially absolute null, it
is desirable that the mechanism be compact, simple in operation and
yet not so costly as to preclude its use in low-cost vehicles.
Present attempts at making such hand-controlled units are directed
to controllers which achieve a center position by various
combinations of opposed springs and interconnecting arms or plates.
While the opposed spring type of centering does return to a center
position, the position is variable beyond allowable tolerances
where a 1/10.degree. dead zone is required. Wandering, which is
inherent in existing systems, increases with the age and use of the
device. Another disadvantage of opposed springs is that to achieve
identical response in opposite directions it is necessary that
springs with identical characteristics be used. Such springs are
virtually impossible to manufacture and this, combined with the
normal changes in spring characteristics due to use and the wearing
of mechanical parts has resulted in a failure to date to produce a
precision, hand-controlled mechanical centering device.
The foregoing disadvantages and limitations of present
hand-controlled systems using opposed springs have prevented the
production of a hand control suitable for navigating a
three-dimensional vehicle such as a submarine. Such a unit is
virtually essential for maneuvering, for example, a deep
submergence search and rescue vehicle to align on a sunken
vehicle's escape hatch or hover in a current over some desired
point on the bottom. A similar application in two-axis control
would be that of yaw for steering and pitch for forward and reverse
control of automobiles either on wide expressways or, with more
precision, through congested traffic. The invention provides the
extremely precise hand control which is necessary in the control of
these and other vehicles. Its cost is low so that it may be
produced for general use and its construction is relatively simple
so that replacement is economically feasible in lieu of attempting
on site repairs.
The present invention achieves its high degree of precision
centering to a null position by means of a null centering assembly
which includes a ground block for providing a firm base or anchor,
protruding appendages on the block against which are positioned and
which restrain a pair of spring plates having a common rotary axis
and which are connected by a single spring, and an adjusting plate
mounted on the same axis as the spring plates and having adjustable
tines which are integral therewith and which extended between the
spring plates. Control about a given axis is precise to within a
dead zone of less than 1/10.degree. and is effected through the
shaft upon which the spring plates and adjusting plate are mounted.
Shaft movement transverse to the direction in which the tines
extend forces the adjacent spring plate on the appropriate axis
away from its protruding appendage under restraint of the spring so
that upon release of the shaft force the spring will return the
spring plate to a stop position against the protruding appendage
and the tines of the adjusting plate. The tines are adjusted by a
set screw which extends through a threaded hole in one tine and
abuts at its end against the other tine. The spring plates are
provided with enlarged ends which extend a sufficient distance to,
at their lower extremity, abut against the block appendage and, at
their upper extremity, accommodate therebetween the tines of the
adjusting plate. The ground block, therefore, is the restraining
member to which either spring plate is returned upon the release of
pressure exerted through the shaft. The adjusting plate, being
mounted on top of the spring plates, prevents any but rotary motion
about the shaft while the tines center the adjusting plate with
respect to the spring plates and provide a reference for
translating mechanical movement into electrical impulses.
Accordingly, it is an object of the present invention to provide a
means for achieving a precise null position in a control unit
operated by hand through movement of a single shaft.
Another object of the invention is to provide a mechanical null
achieving means which can be incorporated by identical units into a
multi-axis system.
A further object of the invention is to provide a null centering
means which does not require matched springs for control in opposed
directions and in which the null is achieved about several axes
through appendages on a single anchor assembly.
Other objects, advantages and novel features of the invention will
become apparent from the following detailed description thereof
when considered in conjunction with the accompanying drawings in
which like numerals represent like parts throughout and
wherein:
FIG. 1 is a perspective view of the hand controller assembly;
FIG. 2 is a plan view of the embodiment of FIG. 1 showing the axes
of motion about which control is effected;
FIG. 3 is a perspective view of the ground block and gimbal housing
and assembly of the embodiment of FIG. 1;
FIG. 4 is a front view of the null centering components shown in
FIG. 3;
FIG. 5 is a side elevation of the null centering components at a
single axis;
FIG. 6 is a schematic diagram showing the disposition of null
centering components about each of three axes of motion; and
FIG. 7 is a sectional view of an assembled embodiment taken along
the pitch axis thereof.
Referring to FIG. 1, the hand controller is shown to include a ball
or hand knob 11 for gripping and operating by hand, a shaft 12
which extends to the interior control elements, a brake lever 13 by
means of which a particular setting of the components is locked in
place, a cover plate 15 and a control element housing 17 which
includes a receptacle 18 for receiving electrical connections. In
FIG. 2, the hand controller is seen in a plan view with the axes of
motion indicated as a pitch axis 20, a roll axis 21 and a yaw axis
22. Hand knob 11 is movable in any direction about a pivot, shown
in FIG. 7, at the base of shaft 12 and since it is connected to
gimbaled elements, positioning the knob in a direction intermediate
of the various axes distributes in the proper proportion the
degrees of motion about each axis which are represented by a single
selected position. In FIG. 3, the device is seen with the housing,
except for the bottom cover, removed. Shaft 12 is rotatably
received in a gimbal yoke 24 with sets of control elements 25 and
26 deployed either on yoke 24 or on the housing as indicated at 27,
respectively. The control elements include an adjusting plate 28
having a pair of tuning fork tines 29 extending therefrom a
selected distance. Tightly positioned for rotation about a common
shaft, not shown, beneath adjusting plate 28 are a pair of spring
plates 32 and 33 which are spaced apart by a protruding appendage
or boss, not shown, on a base block 35 which anchors the assembly.
The spring plates are maintained in contact against the boss by a
spring 36. In FIG. 3, the control elements for motion about the
pitch axis are indicated at 40 while those for motion about the
roll axis are indicated at 41. A similar set of control elements,
not shown, for rotation about the yaw axis is positioned within the
cover 15 of the housing and disposed about shaft 12 with the spring
plates spaced apart by a boss or stop, not shown, on the upper
surface of yoke 24.
FIGS. 4 and 5 show the control elements in more detail, with FIG. 4
showing a front elevation of these elements and with base block 35
indicated schematically at the base of the figure. The boss on
block 35 is indicated at 45 while a pair of abutting members 46 and
47 of spring plates 32 and 33 are shown contacting boss 45.
Abutting members 46 and 47 extend above boss 45 as indicated at 38
and 39 and between these upper extensions the tines 29 of adjusting
plate 24 extend. Tines 29 are spaced apart by a set screw 51 which
extends through one tine and abuts against the other tine as shown.
Centering adjustments are made by positioning adjusting plate 24 so
that tines 29 are substantially centered between spring plates 32
and 33 and thereafter set screw 51 is turned until the tines
contact the adjacent sides of the spring plates. In FIG. 5, a top
view of one set of control elements is shown in the secured or null
position. This view illustrates spring plates 32 and 33 in the zero
position as determined by spreading tines 29 between the upwardly
extending portions 38 and 39 of the respective spring plates.
Adjusting plate 24 is secured in a centered position by a plurality
of bolts 54, 55 and 56.
In FIG. 6, the disposition of respective adjusting plates 24 only
is shown to depict the arrangement of these plates in a three-axis
system. About roll axis 21, for example, the adjacent adjusting
plate depicted is positioned so that movement in either direction
from center will cause one plate to be held against the appendage
stop 45 on block 35 while the other plate is rotated apart
therefrom under spring tension.
In FIG. 7, the assembled device is shown in a section taken through
the pitch and yaw axes. In this view, the subassembly indicated at
59 for controlling motion about the yaw axis is shown mounted on
yoke 24 under brake cover 15 while the subassembly indicated at 60
for controlling motion about the pitch axis is shown as partially
integrated with yoke 24. That is, the adjusting plate is made
integral with the leg of the yoke as shown in FIG. 3 while on the
side of the housing not shown, the adjusting plate for controlling
motion about the roll axis is made integral with the housing
itself. Each of the control assemblies is coupled to the armature
of a microsyn or other rotation sensing electrical device as
indicated at 62 which is adjusted so that its zero output position
is precisely aligned with the mechanical center of its respective
assembly. Thus, in FIG. 7, the zero output of the microsyn or other
device associated with armature 62 is aligned with the mechanical
assembly indicated on the same axis by means of an adjustable pivot
pin 63 and a plurality of pivot pin bolts 64. The bolts are
loosened, the mechanical center of the device is adjusted, the
pivot pin is then aligned with the zero output position of the
microsyn or other device and thereafter the pivot pin bolts are
tightened to secure the assembly in this position. It will be
appreciated that a similar process is followed in each of the other
assemblies so that any mechanical motion is immediately converted
into electrical signals by the movement of each microsyn or device.
FIG. 7 also illustrates the manner in which motion is transferred
from shaft 12 to the various axes through the center of housing 17
which center is positioned at the intersection of the roll, pitch
and yaw axes. In this embodiment, housing 17 is made sufficiently
large to accommodate therein the microsyns, bearings, and other
accessories associated with each axis of motion. Shaft 12 is
coupled to a flexible bellows coupling 66 at the center of the
housing which, in turn, is coupled to an extension of shaft 12 on
the opposite side of block 35 by, respectively, collars 67 and 68
and set screws 69 and 70.
In operation, the controller assembly of the present invention
provides electrical signals proportional to heave (yaw), surge
(pitch) and sway (roll) to appropriate vehicle propulsion
components. The control stick and hand grip knob are moved about a
central axis to achieve the foregoing modes of control. The hand
grip and control stick or shaft 12 are mechanically coupled to
microsyns 62 so that movement of the control stick from the neutral
position displaces the microsyns from their electrical null
position, producing proportional electrical outputs. Excitation for
the microsyns is 3.2 volts rms at 400 H.sub.z. Although the
microsyn has been described as the electrical unit which is coupled
to the mechanical control assemblies, it will be appreciated that
such coupling could also be accomplished with small servos,
potentiometers, or synchro resolvers within the concept of the
invention. The microsyns or other electrical components control the
rate entered into the main propulsion system in an angular manner
similar to control through a rheostat connected to the various axis
controls.
The control assemblies can be adjusted mechanically to a desired
resistance by simply changing the springs to ones having a desired
tension. That is, for certain persons or applications a better feel
of the motion of the device is obtained by adjusting the opposing
force, such as in power brakes in an automobile, to an amount to
which the operator is most sensitive. The device is exceedingly
simple in both construction and operation when considered in
relation to the complex devices in use for providing three-axis
control none of which are known to approach the limit of a
1/10.degree. dead zone.
In construction, the tines of the adjusting plate are made narrower
by a few thousands of an inch than the width of the ground boss on
the ground block. This feature permits the tines to be inserted
between the spring plate leaves while allowing a sufficient
clearance for adjusting the tines to the precise width of the
ground boss.
There is thus provided a hand controller which may be panel mounted
and provides three degrees-of-freedom movement. The controller
converts torques applied to the hand grip or knob into annular
displacements about the torque axes which, in turn, generate
electrical signals proportional to the displacements in roll/surge,
pitch/sway and yaw/heave. Angular displacement about each axis is
restricted to plus or minus 15.degree. from the neutral position
which position is perpendicular to the panel mounting surface. The
spring restraint which is provided for each axis will return the
hand controller to its neutral position when torque is removed. The
lock mechanism will lock the hand controller in any position within
its operating limits. The degrees of control provided by the hand
controller of the present invention are the same as those required
by a helicopter operator using both hands and feet, and the
accuracy of the controller far exceeds that of any existing hand
controller. This accuracy is provided about three axes whereas most
hand controllers are designed to provide control about only two
axes.
A pair of controls has been constructed and has operated with
extreme accuracy in a laboratory mockup of a nuclear submarine
control system. This accuracy is reflected in a dead zone about
each axis of less than 1/10.degree. being achieved. The controls
have been installed in the copilot and pilot stations of the Navy's
DSRV System. Similar units could be used for control of a space
capsule, control of heavy aircraft, and automobile control with the
automobile control especially eliminating the dangerous steering
post and providing throttle control forward and reverse control
aft, steering control left and right and braking control about the
third axis. The device also could be used to control heavy
construction engines and electrical cars and steam cars using
fluidics.
Obviously, many modifications and variations of the present
invention are possible in the light of the above teachings. For
example, as indicated above, the assemblies may be individually or
collectively coupled with other electrical rate devices than the
microsyns described and the spring plates may be varied in shape
and in their relation to the tines within the inventive concept so
long as the device may be adjusted to the width of the ground boss
and each spring plate will be returned to the ground boss when
pressure or torque is removed therefrom.
* * * * *