Force feedback interface devices providing resistance forces using a fluid

• US 6,271,828 B1
• Filed: 11/12/1999
• Issued: 08/07/2001
• Est. Priority Date: 01/18/1995
• Status: Expired due to Term

• Current Assignee: Immersion Corporation
• Original Assignee: Immersion Corporation
• Inventors: Gillespie, Richard B., Schena, Bruce M., Rosenberg, Louis B.
• Primary Examiner(s): CHOW, DOON Y
• Application Number:
  US09/439,836
• Time in Patent Office: 634 Days
• Field of Search: 345/156, 345/157, 345/161, 345/162, 345/179, 744/71.XY, 200/6.A, 341/21, 318/568.1, 318/568.16, 318/568.17
• US Class Current: 345/156
• CPC Class Codes: A61B 90/50 Supports for surgical instruments, e.g. articulated arms
• CPC Class Codes: A63F 13/21 characterised by their sensors, purposes or types
• CPC Class Codes: A63F 13/24 Constructional details thereof, e.g. game controllers with detachable joystick handles
• CPC Class Codes: A63F 13/285 Generating tactile feedback signals via the game input device, e.g. force feedback
• CPC Class Codes: A63F 13/42 by mapping the input signals into game commands, e.g. mapping the displacement of a stylus on a touch screen to the steering angle of a virtual vehicle
• CPC Class Codes: A63F 13/57 Simulating properties, behaviour or motion of objects in the game world, e.g. computing tyre load in a car race game A63F13/56 takes precedence
• CPC Class Codes: A63F 2300/1006 having additional degrees of freedom
• CPC Class Codes: A63F 2300/1037 being specially adapted for converting control signals received from the game device into a haptic signal, e.g. using force feedback
• CPC Class Codes: A63F 2300/1043 being characterized by constructional details
• CPC Class Codes: A63F 2300/6045 for mapping control signals received from the input arrangement into game commands
• CPC Class Codes: A63F 2300/64 for computing dynamical parameters of game objects, e.g. motion determination or computation of frictional forces for a virtual car
• CPC Class Codes: A63F 2300/8082 Virtual reality
• CPC Class Codes: G05G 2009/0474 characterised by means converting mechanical movement into electric signals
• 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: G05G 9/04737 with six degrees of freedom
• CPC Class Codes: G06F 2203/015 Force feedback applied to a joystick
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user
• CPC Class Codes: G06F 3/0338 with detection of limited linear or angular displacement of an operating part of the device from a neutral position, e.g. isotonic or isometric joysticks
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/0383 : Signal control means within the pointing device
• CPC Class Codes: G09B 23/28 : for medicine
• CPC Class Codes: G09B 9/28 : Simulation of stick forces or the like
• CPC Class Codes: Y10T 74/20201 : Control moves in two planes

Abstract

A method and apparatus for interfacing the motion of an object with a digital processing system includes a sensor for detecting movement of the object along a degree of freedom. A passive pneumatic or hydraulic damper is coupled to the object to provide a damping resistance to the object along the degree of freedom and resist a movement of the object. The damping resistance is provided by regulating the control of a fluid with a digital computing apparatus, thus providing a low-cost, low-power force-feedback interface that is safe for the user. The damper and sensor provide an electromechanical interface between the object and the electrical system. A gimbal or other interface mechanism can be coupled between the damper and the object. The interface is well suited for simulations or video games in which an object such as a joystick is moved and manipulated by the user.

Claims

1. An apparatus for interfacing the motion of an object with a host computer, said host computer updating a graphical environment in response to user manipulation of said object and commanding said apparatus to generate force feedback sensations in coordination with events within said graphical environment, said apparatus comprising:

a mechanism providing a degree of freedom to said object with respect to a grounding surface, wherein said object is moveable in said degree of freedom by a user grasping said object;

a sensor in communication with said host computer through an interface and coupled to said mechanism for sensing motion of said object along said first degree of freedom and providing signals to said host computer representing said sensed motion; and

an actuator in communication with said host computer and mechanically coupled to said object to create a resistance to motion of said object along said degree of freedom, said resistance being varied by modulating the viscosity of a fluid in response to signals from said host computer.

2. An apparatus as recited in claim 1 wherein said mechanism includes a gimbal mechanism providing a first revolute degree of freedom to said object engaged with said gimbal mechanism about a first axis of rotation.

3. An apparatus as recited in claim 2 wherein said gimbal mechanism provides a second degree of freedom to said object about a second axis of rotation, and further comprising a second sensor for sensing positions of said object along said second degree of freedom and a second actuator to create a resistance along said second degree of freedom.

4. An apparatus as recited in claim 3 wherein said gimbal mechanism includes a closed loop five member linkage.

5. An apparatus as recited in claim 4 wherein said five member linkage includes:

a ground member coupled to said grounding surface;

first and second extension members, each extension member being coupled to said ground member; and

first and second central members, said first central member having an end coupled to said first extension member and said second central member having an end coupled to said second extension member, wherein said central members are rotatably coupled to each other at ends not coupled to said extension members.

6. An apparatus as recited in claim 1 wherein said actuator includes a fluid that changes its viscous properties in response to an application of an electromagnetic field to said fluid.

7. An apparatus as recited in claim 1 wherein said object includes a joystick.

8. An apparatus as recited in claim 1 further comprising a second actuator in communication with said host computer and mechanically coupled to said mechanism to create a resistance to movement of said object along a second degree of freedom.

9. An apparatus as recited in claim 8 wherein said mechanism includes a first linear member coupled between said object and said actuator to provide a first linear degree of freedom to said object, and a second linear member coupled between said object and said second actuator to provide a second linear degree of freedom to said object.

10. An apparatus as recited in claim 9 wherein said first linear member is a flexible member that flexes when said object is moved in said second degree of freedom, and wherein said second linear member is a flexible member that flexes when said object is moved in said first degree of freedom.

11. A method for interfacing motion of an object with a host computer, said host computer updating a graphical environment in response to user manipulation of said object and commanding said apparatus to generate force feedback sensations in coordination with events within said graphical environment, the method comprising:

providing an object having a degree of freedom with respect to a surface, said object being grasped by a user;

sensing positions of said object along said degree of freedom with respect to said surface using a sensor and producing electrical sensor signals therefrom, said electrical sensor signals being received by said host computer; and

creating a resistance to movement of said object along said degree of freedom, said resistance being varied by modulating the viscosity of a fluid in response to signals received from said host computer.

12. A method as recited in claim 11 wherein said degree of freedom is a rotary degree of freedom.

13. A method as recited in claim 11 wherein said degree of freedom is a rotary degree of freedom.

14. A method as recited in claim 11 wherein said fluid changes its viscous properties in response to an application of an electromagnetic field to said fluid.

15. A computer interface device for use with a host computer updating a graphical environment in response to user manipulation of said interface device, said host computer commanding said computer interface device to generate force feedback sensations in coordination with events within said graphical environment, said interface device comprising:

a user object grasped by a user;

a support mechanism which supports said user object while allowing a degree of freedom of motion of said object with respect to a grounding surface; and

an actuator for providing resistance to motion of said user object along said degree of freedom of said user object, said actuator including a grounded portion and a non-grounded portion, wherein said grounded portion of said actuator remains stationary with respect to said grounding surface, and wherein said resistance to motion is varied by said actuator by modulating a viscosity of a fluid in response to commands from said host computer.

16. A computer interface device as recited in claim 15 further comprising a sensor system that includes an emitter of electromagnetic energy and a detector of said electromagnetic energy.

17. A computer interface device as recited in claim 15 wherein said resistance to motion is a damping resistance.

18. A computer interface device as recited in claim 15 wherein said resistance to motion is a force proportional to a velocity of said user object.

19. A computer interface device as recited in claim 15 wherein said resistance to motion is a sensation representing the feel of moving through a fluid.

20. A computer interface device as recited in claim 15 wherein said resistance to motion is a sensation representing the feel of contacting a wall.

21. A computer interface device as recited in claim 15 wherein said resistance to motion is a sensation representing the feel of moving over a texture.

22. A computer interface device as recited in claim 15 further including a local microprocessor separate from said host computer, said local microprocessor electrically coupled to said actuator and to said sensor system such that said local microprocessor is operative to control said actuator and read said sensor, said local microprocessor coupled to said host computer by a communication interface and executing a local process in parallel with host execution of said graphical simulation.

23. A computer interface device as recited in claim 22 wherein said host computer sends commands to said local microprocessor indicating a magnitude of said resistance to be applied by said actuator.

24. A computer interface device as recited in claim 22 wherein said host computer sends commands to said local microprocessor, said commands indicating a direction of said resistance to be applied by said actuator.

25. A computer interface device as recited in claim 15 wherein said actuator is an electromagnetic actuator.

26. A computer interface device as recited in claim 15 wherein said actuator includes a fluid that changes its viscous properties in response to an electromagnetic field.

27. An interface device for use with a host computer system displaying a graphical object within a graphical environment, said host computer system updating the location of said graphical object in response to user manipulation of said interface device, said host computer system commanding force resistance to said interface device in coordination with interactions between said graphical object and said graphical environment, said interface device comprising:

a user object grasped by a user and movable in a plurality of degrees of freedom with respect to said fixed surface;

a tranducer system coupled to said user manipulatable object, said transducer system including an actuator and a sensor, said actuator providing resistance to motion of said user manipulatable object, and said sensor detecting movement of said user manipulatable object along a degree of freedom and generating a sensor signal; and

a local microprocessor separate from said computer system and coupled to said transducer system for executing a process in parallel with said host computer system, said microprocessor reporting data to said computer system representative of said sensor signal, said microprocessor receiving a command from said host computer system and causing said transducer system to provide said resistance to motion of said object by modulating the viscosity of a fluid in accordance with said host command, wherein said microprocessor decodes said host command and determines a magnitude of said resistance to be applied on said user object that is coordinated with said host computer system updating said graphical environment, wherein said resistance produced by said transducer system upon said user object simulates a feel of at least one of a plurality of feel sensations, said feel sensations including moving through a fluid, moving over a textured surface, and colliding with a simulated obstruction.

28. An interface device as recited in claim 27 wherein said local microprocessor controls said transducer system to vary the resistance on said user object at a desired frequency.

29. An interface device as recited in claim 27 wherein said graphical object is a cursor and wherein said interface device simulates a feel of moving through a fluid when said cursor is moved through a displayed region in said graphical environment.

30. An interface device as recited in claim 27 wherein said graphical object is a cursor and wherein said interface device simulates the feel of encountering an obstacle when said cursor is moved into a graphically displayed obstruction.

31. An interface device as recited in claim 27 wherein said process decodes said host command and determines if said resistance to be applied to said user object should be uni-directional or bi-directional from information in said host command.

32. An interface device as recited in claim 27 wherein said user object is movable in two degrees of freedom that define a planar region and wherein said interface device includes two transducer systems to sense a position and provide resistance in said two degrees of freedom.

33. An interface device as recited in claim 32 wherein said user object is a stylus-receiving user object.

34. An interface device as recited in claim 32 wherein said user object is a finger-receiving user object.

35. An interface device as recited in claim 32 further comprising a first linear member and a second linear member coupled between said user object and said transducer systems, wherein first linear member is a flexible member that flexes when said object is moved in said second degree of freedom, and wherein said second linear member is a flexible member that flexes when said object is moved in said first degree of freedom.

36. An interface apparatus for interfacing the motion of an object with a host computer, the interface apparatus comprising:

a user manipulatable object contacted by a user and moveable in a first degree of freedom;

a sensor in communication with said host computer and coupled to said user manipulatable object to sense positions of said user manipulatable object along said first degree of freedom; and

an actuator in communication with said host computer and mechanically coupled to said user manipulatable object to create a resistance to movement of said object along said first degree of freedom, said actuator providing said resistance by changing the flow rate of a fluid by applying an electric field to said fluid.

37. An interface apparatus as recited in claim 36 wherein said fluid is an electrorheological fluid, and wherein said flow rate is changed by changing a viscosity of said fluid using said electric field.

38. An interface apparatus as recited in claim 36 wherein said actuator includes a piston assembly.

39. An interface apparatus as recited in claim 38 wherein said piston assembly includes a cylinder holding said fluid and a piston operative to move within said cylinder, said piston being coupled to said user manipulatable object.

40. An interface apparatus as recited in claim 39 wherein said cylinder is sealed to prevent said fluid from leaving said cylinder, and wherein said piston includes an aperture such that said piston may move within said cylinder when said fluid flows through said aperture.

41. An interface apparatus as recited in claim 40 wherein said aperture includes at least one electrode for applying said electric field to said electrorheological fluid, wherein said host computer controls said electric field.

42. An interface apparatus as recited in claim 41 wherein said piston includes a plurality of apertures, each of said apertures including at least one electrode.

43. An interface apparatus as recited in claim 42 wherein at least one of said plurality of said apertures has a size different from another one of said apertures.

44. An interface apparatus as recited in claim 41 further comprising a local microprocessor separate from said host computer for controlling said electric field with said at least one electrode and controlling said resistance on said user manipulatable object based on commands received from said host computer.

45. An interface apparatus as recited in claim 40 wherein said fluid is a liquid.

46. An interface apparatus as recited in claim 39 wherein said piston is coupled to said user manipulatable object by a piston rod, wherein said piston rod includes two ends, each end including a ball joint.

47. An interface apparatus as recited in claim 36 wherein said user manipulatable object includes one of a joystick handle and a mouse.

48. An interface apparatus as recited in claim 36 wherein said actuator is a first actuator, and further comprising a second actuator in communication with said host computer and coupled to said user manipulatable object to create a resistance to movement of said user manipulatable object along a second degree of freedom, said second actuator providing said resistance by changing the flow rate of a fluid by applying an electric field to said fluid.

49. An interface apparatus as recited in claim 48 further comprising a first linear member coupled between said user manipulatable object and said first actuator to provide a first linear degree of freedom to said user manipulatable object, and a second linear member coupled between said user manipulatable object and said second actuator to provide a second linear degree of freedom to said user manipulatable object.

50. An interface apparatus as recited in claim 49 wherein said first linear member is a flexible member that flexes when said user manipulatable object is moved in said second degree of freedom, and wherein said second linear member is a flexible member that flexes when said user manipulatable object is moved in said first degree of freedom.

51. A method for providing force feedback to a user manipulatable object included in an interface device and physically contacted by a user, said interface device in communication with a host computer, the method comprising:

sensing movement of said user manipulatable object in at least one degree of freedom and informing said host computer of said sensed movement; and

outputting a resistance on said user manipulatable object, said resistance being provided by controlling the flow of a liquid by changing the viscosity of said liquid.

52. A method as recited in claim 51 wherein said liquid is an electrorheological fluid, wherein said viscosity of said electrorheological fluid is changed by applying an electric field.

53. A method as recited in claim 52 wherein said electric field is controlled by a host computer.

54. A method as recited in claim 52 wherein said electric field is controlled by a microprocessor local to said interface device and separate from a host computer.

55. An interface apparatus for interfacing the motion of an object with a host computer, the interface apparatus comprising:

a user manipulatable object grasped by a user and moveable in a first degree of freedom;

a sensor in communication with said host computer and coupled to said user manipulatable object to sense positions of said user manipulatable object along said first degree of freedom; and

an actuator in communication with said host computer and mechanically coupled to said user manipulatable object to create a resistance to movement of said object along said first degree of freedom, said actuator providing said resistance by changing the flow rate of a fluid by modulating the viscosity of said fluid.

56. An interface apparatus as recited in claim 55 wherein said fluid is an electrorheological fluid, and wherein said viscosity of said fluid is modulated by using an electric field.