Force reflecting haptic interface

• US 5,625,576 A
• Filed: 10/01/1993
• Issued: 04/29/1997
• Est. Priority Date: 10/01/1993
• Status: Expired due to Term

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Massie, Thomas H., Salisbury, J. Kenneth Jr.
• Primary Examiner(s): Cosimano, Edward R.
• Application Number:
  US08/130,639
• Time in Patent Office: 1,306 Days
• Field of Search: 318/628, 364/578, 395/99
• US Class Current: 703/6
• CPC Class Codes: B25J 13/02 Hand grip control means handles or pedals for crane control B66C13/56; for measuring the force applied to control members G01L5/22; hand-held casings for switching devices, e.g. joy-sticks H01H9/0214
• CPC Class Codes: B25J 9/1689 Teleoperation
• CPC Class Codes: G05B 11/01 electric
• CPC Class Codes: G05B 17/02 electric
• CPC Class Codes: G05B 2219/23021 Gesture programming, camera sees hand, displays it on screen, grasp buttons
• CPC Class Codes: G05G 1/52 Controlling members specially adapted for actuation by other parts of the human body than hand or foot
• CPC Class Codes: G05G 2009/04766 providing feel, e.g. indexing means, means to create counterforce
• CPC Class Codes: G05G 9/047 the controlling member being movable by hand about orthogonal axes, e.g. joysticks for switches H01H25/04
• CPC Class Codes: G06F 2203/0331 Finger worn pointing device
• CPC Class Codes: G06F 3/014 Hand-worn input/output arrangements, e.g. data gloves
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user
• CPC Class Codes: G06F 3/033 Pointing devices displaced or positioned by the user , e.g. mice, trackballs, pens or joysticks; Accessories therefor digitisers characterised by the transducing means G06F3/041
• CPC Class Codes: G06F 3/0346 with detection of the device orientation or free movement in a 3D space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors
• CPC Class Codes: G06F 3/0383 Signal control means within the pointing device
• CPC Class Codes: G06G 7/48 Analogue computers for specific processes, systems or devices, e.g. simulators

Abstract

A connection element such as a thimble connects to a user'"'"'s body member and, through a linkage, to a ground reference. The apparatus physically exchanges a force with a user in an environment local to the user. The linkage powers at least three independent freedoms of the connection element relative to the reference. It also maintains at least one independent freedom of the connection element relative to the reference free of power. Up to three independent freedoms of the connection element may be maintained free of power, and up to five independent freedoms may be powered. A gimbal connects the gimbal to the linkage. Zero, one or two of the gimbal axes may be powered. A five bar linkage connects the connection element to a counter-balance that also includes two actuators. A third actuator connects the five bar linkage to the reference. The two actuators of the counterbalance may be connected to the next link in the chain to the reference through a single cable. Signal processing equipment powers the actuators to deliver a signal at the connection element that represents a virtual situation generated by a programmed computer, or physical conditions in a remote environment. A virtual switch presents to the user the force and displacement relationship of a spring switch. A virtual bristled brush presents the force and displacement relationship of such a brush, while also changing the virtual environment to reflect the user'"'"'s changes in location.

Claims

1. An apparatus for physically exchanging a force with a user in a first, user-local environment, said apparatus comprising:

a. a connection element for physically connecting to a body member of said user; and

b. means for physically linking said connection element to a reference, said linking means comprising;

i. means for powering three independent freedoms of said connection element relative to said reference; and

ii. means for maintaining three independent freedoms of said connection element relative to said reference free of power.

2. The apparatus of claim 1, said means for powering said freedoms powering said freedoms based on a signal generated in a non-local environment.

3. The apparatus of claim 1, at least one of said powered freedoms comprising a translation relative to said reference.

4. The apparatus of claim 1, said at least one freedom that is free of power comprising a rotation with respect to said reference.

5. The apparatus of claim 1, said linking means comprising at least two linked orthogonal bearings.

6. The apparatus of claim 1, said connecting element sized to engage a body member of said user selected from the group consisting of a human hand, head, buttocks, arm, leg, tongue and toe.

7. The apparatus of claim 1, said linking means further comprising:

a. means for tracking the motions of said connection element relative to said reference with respect to said at least three freedoms that are powered; and

b. means for generating a signal based on said tracked motions.

8. The apparatus of claim 1, said connection element comprising an element that bears compression.

9. The apparatus of claim 1, said connection element comprising an element that bears tension.

10. The apparatus of claim 1, said connection element comprising means for exchanging an attractive force and a repulsive force with said user.

11. An apparatus for physically exchanging a force with a user in a first, user-local environment, said apparatus comprising:

a. a connection element for physically connecting to a body member of said user; and

b. means for physically linking said connection element to a reference, said linking means comprising;

i. means for powering at least three independent freedoms of said connection element relative to said reference;

ii. means for maintaining at least one independent freedom of said connection element relative to said reference free of power; and

iii. first and second linked orthogonal bearings and a third bearing, which is linked to and orthogonal to one of either the first or second linked bearings.

12. The apparatus of claim 11, each bearing having an axis of rotation, said three axes of rotation coinciding at a user reference point.

13. The apparatus of claim 12, said connection element comprising a thimble into which said body member is inserted, said thimble arranged such that said user reference point is within said body member when connected to said thimble.

14. The apparatus of claim 13, said body member comprising a finger.

15. An apparatus for physically exchanging a force with a user in a first, user-local environment, said apparatus comprising:

a. a connection element for physically connecting to a body member of said user; and

b. means for physically linking said connection element to a reference, said linking means comprising;

i. means for powering at least three independent freedoms of said connection element relative to said reference; and

ii. means for maintaining at least one independent freedom of said connection element relative to said reference free of power; and

iii. a pair of actuators that are movable relative to each other and relative to a link more proximal to said reference than said pair of actuators, said pair of actuators being both connected to said link more proximal to said reference through a single cable.

16. An apparatus for physically exchanging a force with a user in a first, user-local environment, said apparatus comprising:

a. a connection element for physically connecting to a body member of said user; and

b. means for physically linking said connection element to a reference, said linking means comprising;

i. means for powering at least three independent freedoms of said connection element relative to said reference;

ii. means for maintaining at least one independent freedom of said connection element relative to said reference free of power; and

iii. at least two masses that are movable relative to said reference and each other and said connection element so that the center of mass among said at least two masses and the connection element remains substantially stationary relative to said reference despite motion of said connection element.

17. The apparatus of claim 16, at least one of said masses comprising an actuator.

18. An apparatus for physically exchanging a force with a user in a first, user-local environment, said apparatus comprising:

a. a connection element for physically connecting to a body member of said user; and

b. means for physically linking said connection element to a reference, said linking means comprising;

i. means for powering at least three independent freedoms of said connection element relative to said reference;

ii. means for maintaining at least one independent freedom of said connection element relative to said reference free of power; and

iii. a five bar linkage.

19. The apparatus of claim 18, four bars of said five bar linkage defining a plane, said four bars being connected to said reference, rotatably about an axis perpendicular to said plane.

20. An apparatus for physically exchanging a force with a user in a first, user-local environment, said apparatus comprising:

a. a connection element comprising a thimble, for physically connecting to a body member of said user; and

b. means for physically linking said connection element to a reference, said linking means comprising;

i. means for powering at least three independent freedoms of said connection element relative to said reference; and

ii. means for maintaining at least one independent freedom of said connection element relative to said reference free of power.

21. An apparatus for physically exchanging a force with a user in a first, user-local environment, said apparatus comprising:

a. a connection element comprising a rod, for physically connecting to a body member of said user; and

b. means for physically linking said connection element to a reference, said linking means comprising;

i. means for powering at least three independent freedoms of said connection element relative to said reference; and

ii. means for maintaining at least one independent freedom of said connection element relative to said reference free of power.

22. An apparatus for physically exchanging a force with a user in a first, user-local environment, said apparatus comprising:

a. a connection element comprising a rod, for physically connecting to a body member of said user; and

b. means for physically linking said connection element to a reference, said linking means comprising;

i. means for powering at least four independent freedoms of said connection element relative to said reference; and

ii. means for maintaining at least one independent freedom of said connection element relative to said reference free of power.

23. An apparatus for physically exchanging force with a user in a first, user-local environment, said apparatus comprising:

a. a connection element comprising a rod, for physically connecting to a body member of said user; and

b. means for physically linking said connection element to a reference, said linking means comprising;

i. means for powering at least five independent freedoms of said connection element relative to said reference; and

ii. means for maintaining at least one independent freedom of said connection element relative to said reference free of power.

24. An apparatus for physically exchanging a force with a user in a first, user-local environment, said apparatus comprising:

a. a connection element sized to engage a human finger, for physically connecting to a body member of said user; and

b. means for physically linking said connection element to a reference, said linking means comprising;

i. means for powering at least three independent freedoms of said connection element relative to said reference; and

ii. means for maintaining at least one independent freedom of said connection element relative to said reference free of power.

25. An apparatus for physically exchanging a force with a user in a first, user-local environment, said apparatus comprising:

a. a connection element sized to engage a human foot, for physically connecting to a body member of said user; and

b. means for physically linking said connection element to a reference, said linking means comprising;

i. means for powering at least three independent freedoms of said connection element relative to said reference; and

ii. means for maintaining at least one independent freedom of said connection element relative to said reference free of power.

26. An apparatus for physically exchanging a force with a user in a first, user-local environment, said apparatus comprising:

a. a connection element for physically connecting to a body member of said user; and

means for physically linking said connection element to a reference located above said connection element, with respect to a gravitational field, said linking means comprising;

i. means for powering at least three independent freedoms of said connection element relative to said reference; and

ii. means for maintaining at least one independent freedom of said connection element relative to said reference free of power.

27. An apparatus for physically exchanging a force with a user in a first, user-local environment, said apparatus comprising:

a. a connection element for physically connecting to a body member of said user; and

b. means for physically linking said connection element to a reference, said linking means comprising;

i. means for powering at least three independent freedoms of said connection element relative to said reference; and

ii. means for maintaining at least one independent freedom of said connection element relative to said reference free of power;

iii. means for linking to a different portion of said user'"'"'s body from said body member, such that said reference is said different portion of said user'"'"'s body.

28. A user input apparatus comprising:

a. a user connection element;

b. a linkage for connecting said user connection element to said reference, said linkage comprising;

i. a connection assembly, comprising;

(a). a first link;

(b). a first rotational bearing, one side of which is connected to said connection element and the other side of which is connected to one end of said first link;

(c). a second rotational bearing, one side of which is connected to a second end of said first link and the other side of which is connected to a second link, said second bearing arranged relative said first bearing such that their axes of rotation are orthogonal and intersect; and

(d). a third rotational bearing, one side of which is connected to a second end of said second link, said third bearing arranged relative to said second bearing such that their axes of rotation are orthogonal and intersect, and arranged relative to said first bearing, such that their axes of rotation intersect;

ii. four bars, linked in a series having first and last bars, an extension of one of said bars being connected to the other side of said third bearing;

iii. an axle that is fixed relative to a link that is more proximal to said reference than said axle, said first and last bars of said linked series being linked by said axle;

iv. a first actuator, connected between said first bar of said four bar series and said link more proximal to said reference than said axle;

v. a second actuator, connected between said link more proximal to said reference than said axle and a bar of said four bar series other than said first bar of said series; and

vi. a third actuator, connected between said reference and said link more proximal to said reference than said axle.

29. The apparatus of claim 28, said first and second actuators being connected to said link more proximal to said reference than said axle through a single cable.

30. An apparatus for a user in a local environment to transmit a signal to and receive a signal from a non-local environment, said apparatus comprising:

a. a connection element for physically connecting to a body member of said user;

b. means for mechanically linking said connection element to a reference, said linking means comprising;

i. means for powering at least three independent freedoms of said connection element relative to said reference to an extent based on a signal from said non-local environment;

ii. means for tracking said at least three powered independent freedoms;

iii. means for generating a master signal based on said tracked at least three freedoms; and

iv. means for maintaining at least two independent freedoms of said connecting element relative to said reference free of powering;

c. means for communicating said master signal from said means for tracking to said non-local environment; and

d. means for communicating said non-local signal from said non-local environment to said means for powering.

31. The apparatus of claim 30, said linking means comprising means for maintaining three independent freedoms of said connection element relative to said reference free of powering.

32. The apparatus of claim 30, said linking means comprising at least two linked orthogonal bearings.

33. The apparatus of claim 30, said linking means comprising a pair of actuators that are movable relative to each other and a link more proximal to said reference than said actuators.

34. An apparatus for generating a force at a specified point, said apparatus comprising:

a. a first actuator connected through a cable to a ground;

b. a second actuator connected to said ground through said cable;

c. means for kinematically connecting said first actuator to said specified point; and

d. means for kinematically connecting said second actuator to said specified point.

35. The apparatus of claim 34, said means for connecting said first actuator to said specified point comprising a first bar of a five bar linkage.

36. The apparatus of claim 35, said means for connecting said second actuator to said specified point comprising a second bar of said five bar linkage.

37. The apparatus of claim 36, said bars of said five bar linkage having lengths and masses such that the center of mass among said actuators, bars and specified point remains substantially stationary, despite any relative movement of said actuators, bars and point.

38. A method for physically exchanging a force between an apparatus and a user in a first, user-local environment, said method comprising the steps of:

a. providing an apparatus comprising;

i. a connection element for physically connecting to a body member of said user; and

ii. means for physically linking said connection element to a reference, said linking means comprising;

(a). means for powering at least three independent freedoms of said connection element relative to said reference; and

(b). means for maintaining three independent freedoms of said connection element relative to said reference free of power;

b. connecting said connection element to a body member of said user;

c. powering said at least three independent freedoms of said connection element.

39. The method of claim 38, wherein said step of powering said freedoms comprises the step of generating a signal in a non-local environment and powering said freedoms based on said non-local signal.

40. An apparatus for sensing a position at a specified point, said apparatus comprising:

a. a first rotary position transducer connected through a cable to a ground;

b. a second rotary position transducer connected to said ground through said cable;

c. means for kinematically connecting said first rotary position transducer to said specified point; and

d. means for kinematically connecting said second rotary position transducer to said specified point.

41. An apparatus for generating a position at a specified point, said apparatus comprising:

a. a first actuator connected through a cable to a ground;

b. a second actuator connected to said ground through said cable;

c. means for kinematically connecting said first actuator to said specified point; and

d. means for kinematically connecting said second actuator to said specified point.

42. An apparatus for sensing a force at a specified point, said apparatus comprising:

a. a first actuator connected through a cable to a ground;

b. a second actuator connected to said ground through said cable;

c. means for kinematically connecting said first actuator to said specified point; and

d. means for kinematically connecting said second actuator to said specified point.