Power management for interface devices applying forces

• US 20020126091A1
• Filed: 02/19/2002
• Published: 09/12/2002
• Est. Priority Date: 09/27/1995
• Status: Active Grant

• Current Assignee: Immersion Corporation Delaware
• Original Assignee: Immersion Corporation
• Inventors: Schena, Bruce M., Rosenberg, Louis B., Braun, Adam C.
• Granted Patent: US 7,038,657 B2
• Time in Patent Office: Days
• US Class Current: 345/161
• CPC Class Codes: A63F 13/21 characterised by their sensors, purposes or types
• CPC Class Codes: A63F 13/23 for interfacing with the game device, e.g. specific interfaces between game controller and console
• CPC Class Codes: A63F 13/235 using a wireless connection, e.g. infrared or piconet
• CPC Class Codes: A63F 13/285 Generating tactile feedback signals via the game input device, e.g. force feedback
• 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 13/803 Driving vehicles or craft, e.g. cars, airplanes, ships, robots or tanks
• CPC Class Codes: A63F 2300/1025 details of the interface with the game device, e.g. USB version detection
• CPC Class Codes: A63F 2300/1031 using a wireless connection, e.g. Bluetooth, infrared connections
• 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 2300/64 for computing dynamical parameters of game objects, e.g. motion determination or computation of frictional forces for a virtual car
• CPC Class Codes: A63F 2300/8017 Driving on land or water; Flying
• CPC Class Codes: A63F 2300/8082 Virtual reality
• CPC Class Codes: G05G 2009/04766 providing feel, e.g. indexing means, means to create counterforce
• CPC Class Codes: G05G 2009/04777 with additional push or pull action on the handle
• 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 1/266 Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips
• CPC Class Codes: G06F 2203/014 Force feedback applied to GUI
• CPC Class Codes: G06F 2203/015 Force feedback applied to a joystick
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user
• CPC Class Codes: G06F 3/0383 : Signal control means within the pointing device
• CPC Class Codes: H01H 2003/008 : with a haptic or a tactile feedback controlled by electrical means, e.g. a motor or magnetofriction
• CPC Class Codes: H04L 67/131 : Protocols for games, networked simulations or virtual reality

Abstract

A method and apparatus for providing safe and low-cost force feedback peripherals for consumer applications. A device microprocessor local to an interface device is coupled to the host by a first interface bus. The microprocessor receives host commands from the host computer on the first interface bus, such as an RS-232 interface, and commands an actuator to apply a force to a user object, such as a joystick, in response to host commands. A sensor detects positions of the user object and outputs signals to the host on a second interface bus, such as a PC game port bus, separate from the first bus. In a “recoil” embodiment, a user initiates force feedback by pressing a button on the joystick, which sends an activation signal to the actuator. In other recoil embodiments, the host computer can transmit one or more enable signals and/or activation signals to the actuator to enable or command forces. A safety switch of the present invention disables the actuator when the interface device is not in use and enables the actuator when an amount of weight over a predetermined amount is placed on the joystick created by a user grasping the joystick. A circuit of the present invention includes a capacitor for storing power provided by an input signal and supplied to the actuator when forces are to be output.

Claims

1. An interface apparatus for interfacing motion of a user manipulable object with a host computer and enabling said host computer to track motion of said user manipulable object and to command feedback forces to said user manipulable object, said interface apparatus comprising:

a user object being physically contacted and manipulable by a user and having at least one degree of freedom of movement with respect to a ground surface;

a device microprocessor provided local to said interface apparatus and separate from said host computer and being controlled by software instructions stored in a memory device separate from said host computer, said microprocessor being coupled to said host computer by a first interface bus and receiving host commands from said host computer on said first interface bus;

an actuator coupled to said user object for applying a force along said degree of freedom to said user object, wherein said actuator applies said force in response to microprocessor force commands produced by said device microprocessor; and

a sensor coupled to said user object for detecting a position of said user object along said degree of freedom and for outputting a locative sensor signal which represents said position of said user manipulable object, said locative sensor signal being received by said host computer on a second interface bus that is coupled between said interface apparatus and said host computer and which is separate from said first interface bus, and wherein said host computer modifies a displayed process in response to said locative sensor signal.

2. An interface apparatus as recited in claim 1 wherein said first interface bus is a serial interface bus for transmitting and receiving data serially.

3. An interface apparatus as recited in claim 2 wherein said first interface bus is an RS-232 interface bus coupled to an RS-232 interface port of said host computer.

4. An interface apparatus as recited in claim 3 wherein said second interface bus is a game port interface bus coupled to a personal computer game port of said host computer.

5. An interface apparatus as recited in claim 4 wherein said user object includes a joystick.

6. An interface apparatus as recited in claim 4 wherein said sensor is a first sensor and said locative sensor signal is a first locative sensor signal, and further comprising a second sensor coupled to said device microprocessor, wherein said first sensor outputs said first locative sensor signal to said host computer on said first interface bus, and wherein said second sensor detects said position of said joystick along said degree of freedom independently of said first sensor and outputs a second locative sensor signal to said microprocessor.

7. An interface apparatus as recited in claim 6 further comprising a button device coupled to said interface apparatus, said button device providing a button input signal to said microprocessor when said user activates said button, said microprocessor providing said button input signal to said host computer using said game port interface bus.

8. An interface apparatus as recited in claim 7 wherein said microprocessor, said first sensor, said second sensor, and said button are powered by said host computer using a power line of said game port interface bus.

9. An interface apparatus as recited in claim 7 wherein said microprocessor, said first sensor, said second sensor, and said button are powered by said host computer using a power line of said RS-232 interface bus.

10. An interface apparatus as recited in claim 8 wherein said actuator is powered by a power supply separate from said host computer and said game port interface bus.

11. A force feedback interface device as recited in claim 2 further comprising a power store circuit coupled to said actuator, said power store circuit storing power from a power source and providing said stored power to said actuator when said actuator applies said force to said user object, said power store circuit including a capacitor that charges to store said power and discharges said stored power for said actuator.

12. An interface apparatus as recited in claim 1 further comprising a thermal sensor for detecting a temperature of said actuator, said thermal sensor providing a temperature signal to said microprocessor such that said microprocessor can deactivate said actuator when said temperature of said actuator rises above a predetermined threshold.

13. An interface apparatus as recited in claim 5 wherein said microprocessor deactivates said actuator when at least one of said plurality of buses is disconnected from said host computer or disconnected from said interface apparatus.

14. An interface apparatus as recited in claim 5 further comprising a safety switch for said user, wherein said actuator is operative to output said force only when said safety switch is closed.

15. An interface apparatus as recited in claim 14 wherein said safety switch is a hand-weight safety switch coupled to said joystick, said hand weight safety switch being closed by said user when said user applies weight to said joystick by grasping said joystick.

16. An interface apparatus as recited in claim 5 wherein said joystick includes a safety break-away handle that breaks off from said interface apparatus when a force over a predetermined threshold is applied to said joystick.

17. An interface apparatus as recited in claim 16 wherein said safety break-away handle is attached to said interface apparatus by a magnet.

18. An interface apparatus as recited in claim 6 further comprising a local memory device separate from said host computer, said local memory device storing at least one force routine, wherein said microprocessor selects a force routine in accordance with said at least one of said host commands, said force routine determining said microprocessor force commands, at least in part, from said sensor signals of said microprocessor sensors.

19. An interface apparatus as recited in claim 1 wherein said selected force routine retrieves a plurality of digital force values stored in said local memory device and outputs said stored force values to said actuator.

20. An interface apparatus for interfacing motion of a user manipulable joystick with a host computer, said interface apparatus comprising:

a joystick being physically contacted by a user and having at least one degree of freedom of movement;

an actuator coupled to said joystick for applying a force along said degree of freedom to said joystick;

wherein said actuator applies said force in response to force commands received from said host computer via a first interface bus coupling said interface apparatus to a first interface port of said host computer; and

a sensor for detecting a position of said joystick along said degree of freedom and outputting sensor signals, said sensor signals being received by said host computer via a second interface bus coupling said interface apparatus to a PC game port of said host computer, said PC game port being a separate port from said first interface port.

21. An interface apparatus as recited in claim 20 wherein said first interface port is an RS-232 port.

22. An interface apparatus as recited in claim 20 wherein said force commands received by said actuator are host data sent by said host computer and which instruct said actuator to output said force in accordance with a software process running on said host computer.

23. An interface apparatus as recited in claim 22 wherein said first interface bus transmits said host data serially to said interface apparatus from said host computer, and further comprising at least one shift register for providing said serial host data as control signals to said actuator.

24. An interface apparatus as recited in claim 23 further comprising a programmable logic device for receiving said control signals from said at least one shift register and controlling said force from said actuator using said control signals.

25. An interface apparatus as recited in claim 23 wherein said interface bus transmits at least a portion of said host data in parallel in conjunction with said serially transmitted host data.

26. An interface apparatus as recited in claim 23 wherein said interface bus is an RS-232 interface bus in which two lines are used to transmit data to said interface apparatus as parallel information and in which one line is used to transmit data to said interface apparatus as serial information.

27. An interface apparatus as recited in claim 23 wherein said interface bus is an RS-232 interface bus in which all lines included in said RS-232 bus are used to transmit data to said interface apparatus as parallel information.

28. An interface apparatus as recited in claim 25 wherein said actuator is a motor and said sensor is an analog potentiometer.

29. An interface apparatus as recited in claim 22 further comprising a button device coupled to said interface apparatus, said button device providing a button input signal to said host computer via said second serial interface bus when said user activates said button.

30. An interface apparatus as recited in claim 23 wherein said actuator is deactivated when at least one of said first and second interface buses is disconnected from said host computer or disconnected from said interface apparatus.

31. An interface device as recited in claim 20 further comprising a device microprocessor provided local to said interface apparatus and separate from said host computer, said microprocessor being coupled to said host computer by said first serial interface bus, wherein said microprocessor receives host commands from said host computer on said first serial interface bus and provides processor host commands to said actuator to command said actuator to apply said force to said joystick.

32. An interface apparatus as recited in claim 20 further comprising a hand-weight safety switch for said user and coupled to said joystick, wherein said actuator is operative to output said force only when said safety switch is closed, said hand weight safety switch being closed by said user when said user applies weight to said joystick by grasping said joystick.

33. An interface apparatus as recited in claim 20 further comprising an optical safety switch for said user and coupled to said joystick, wherein said actuator is operative to output said force only when said safety switch is closed, said optical safety switch being closed by said user when said user blocks an optical sensor of said optical safety switch by contacting said joystick.

35. A force feedback interface device as recited in claim 34 wherein said user object is a joystick, and wherein said first interface bus is a game port interface bus coupled to a game port of said host computer.

36. A force feedback interface device as recited in claim 34 wherein said actuator applies said force on said joystick only when said user selects said user-selectable device.

37. A force feedback interface device as recited in claim 34 wherein said user selectable control includes a button.

38. A force feedback interface device as recited in claim 37 wherein said host computer is coupled to said actuator by a second interface bus operative to transmit an enable signal from said host computer to said interface apparatus for enabling said reflex process, wherein when said enable signal is provided by said host computer, said selection of said user-selectable control causes said actuator to output said force, and wherein when said enable signal is not provided by said host computer, said selection of said user selectable control does not cause said actuator to output said force.

39. A force feedback interface device as recited in claim 38 wherein said activation signal is a first activation signal, and wherein said host computer is operative to provide a second activation signal to said actuator via said second interface bus to command said actuator to apply said force to said user object regardless of whether said first activation signal from said user selectable control has been provided to said actuator.

40. A force feedback interface device as recited in claim 39 wherein said second activation signal is provided at a desired baud rate to said actuator such that said second activation signal activates and deactivates said actuator at said desired baud rate.

41. A force feedback interface device as recited in claim 39 further comprising a user enable switch on said interface device which, when selected, enables said reflex process to output force in response to said user-selectable control and, when unselected, disables said reflex process from applying said force in response to said user-selectable control.

42. A force feedback interface device as recited in claim 37 further comprising a power store circuit coupled to said actuator, said power store circuit storing power from a power source and providing said stored power to said actuator when said actuator applies said force to said user object.

43. A force feedback interface device as recited in claim 42 wherein said power store circuit includes a capacitor that charges to store said power and discharges said stored power for said actuator.

44. A force feedback interface device as recited in claim 43 wherein said power store circuit stores power received from said host computer over a second interface bus coupled to said host computer.

45. A force feedback interface device as recited in claim 44 wherein said second interface bus is a serial interface bus.

46. A force feedback interface device as recited in claim 44 wherein said host computer is a video game console, and wherein said second interface bus is coupled to a control port of said video game console.

47. A force feedback interface device as recited in claim 37 further comprising a safety switch for said user, wherein said actuator is operative to output said force only when said user continually closes said safety switch during operation of said interface device.

48. A force feedback interface device as recited in claim 47 wherein said safety switch is a hand-weight safety switch coupled to said joystick, said hand weight safety switch being closed by said user when said user applies weight to said joystick by grasping said joystick.

49. A force feedback interface device as recited in claim 47 wherein said safety switch includes two touch plates coupled to said force feedback interface device, wherein said safety switch is closed when said user creates an electrical connection between said two touch plates by touching both of said touch plates.

50. A force feedback interface device as recited in claim 37 further comprising a timer/pulse generator and actuator drive electronics for driving said actuator.

51. A force feedback interface device as recited in claim 50 wherein when said button is continually depressed by said user, said timer/pulse generator causes said actuator to repeatedly output forces to said user object.

34. A force feedback interface device for use with a host computer and for implementing a force reflex process independently of said host computer, the interface device comprising:

a sensor for determining the position of a user object in a degree of freedom and for providing sensor signals representing said position to said host computer via a first interface bus;

an actuator for applying a force on said user object when said actuator receives an activation signal; and

a user-selectable control coupled to said interface device, wherein when said user selects said user-selectable control, a reflex process is initiated in which said activation signal is sent to said actuator and commands said actuator to apply said force on said user object, thereby initiating force feedback on said interface device independently of said host computer.

52. A force feedback interface device for safe use by a user, said interface device comprising:

a sensor for sensing the position of a user object along a degree of freedom and for providing a sensor signal indicating said position of said user object to a host computer coupled to said interface device;

an actuator for applying a force to said user object along said degree of freedom;

a safety switch coupled to said user object for disabling said actuator when said user is not using said interface device, said safety switch enabling said actuator when more than a predetermined amount of weight is placed on said user object.

53. An interface device as recited in claim 52 wherein said user object includes a joystick.

54. An interface device as recited in claim 53 wherein an amount of weight created by a user grasping said joystick is more than said predetermined amount of weight and enables said actuator.

55. An interface device as recited in claim 54 wherein said joystick includes a handle portion and a base portion, said handle portion being translatably coupled to said base portion.

56. An interface device as recited in claim 55 wherein said safety switch includes a contact on said handle portion and a contact on said base portion such that when said predetermined amount of weight is applied to said user object, said handle portion engages said base portion and said contacts engage to allow electrical current to flow therebetween.

57. An interface device as recited in claim 56 further comprising a spring member positioned between said handle portion and said base portion of said joystick, said spring member forcing said handle portion and said base portion apart from each other when less than said predetermined amount of weight is applied to said joystick.

58. An interface device as recited in claim 53 wherein said actuator is one of a plurality of actuators included in said interface device, wherein said safety switch is operative to enable and disable said plurality of actuators.

60. A circuit as recited in claim 59 wherein said sensing device includes an analog to digital converter and a microprocessor operative to monitor said input signal to determine when said capacitor is fully charged.

61. A circuit as recited in claim 59 further comprising a driver circuit for receiving said control signal and for amplifying said control signal using said supplied stored power to drive said actuator.

62. A circuit as recited in claim 61 further comprising a current limiter coupled to said input signal for limiting a current of said input signal to a predetermined value and providing said limited current to said capacitor.

63. A circuit as recited in claim 61 wherein said input signal is received from a game port interface bus coupled to a game port of said host computer system.

64. A circuit as recited in claim 61 wherein said input signal is received from an interface bus coupled to a control port of said host computer system, wherein said host computer system is a video game console.

65. A circuit as recited in claim 61 wherein said input signal is received from a power supply included in said interface device.

59. A circuit for storing power in a force feedback interface device that interfaces a user with a host computer system, said circuit comprising:

a capacitor for storing power provided by a signal input to said circuit;

a sensing device coupled to said capacitor for sensing when said capacitor is fully charged; and

a control device for providing a control signal to an actuator so that said actuator can apply force to a user object of said interface device, wherein said stored power is supplied to said actuator to apply said force.

66. A method for interfacing a force feedback interface device manipulated by a user with a host computer system, the method comprising the steps of:

providing a user manipulable joystick included in said force feedback interface device, said joystick having a degree of freedom;

sensing positions of said joystick along said degree of freedom with a sensor and producing electrical sensor signals therefrom, said sensor signals being sent to said host computer system over a first interface bus to a game port of said host computer system;

utilizing a microprocessor local to said joystick and separate from said host computer system to communicate with said host computer system to receive host commands from said host computer system on a second interface bus;

selecting a reflex process stored in a memory local to said microprocessor in accordance with said at least one of said host commands; and

outputting processor force commands from said microprocessor to an actuator utilizing said reflex process and said electrical sensor signals, said actuator being coupled to said joystick and being operative to apply a force to said joystick in accordance with said processor force commands.

67. A method as recited in claim 66 wherein said second bus is coupled to an RS-232 port of said host computer system.

68. A method as recited in claim 66 wherein said sensor is an analog potentiometer.

69. A method as recited in claim 66 further comprising a step of updating game software or simulation software implemented by said host computer system in accordance with said position signals.

70. A method as recited in claim 69 wherein said selected reflex process retrieves a plurality of stored digital force values and outputs said stored force values to said actuator.

71. An interface apparatus for interfacing motion of a user manipulable object with a host computer and enabling said host computer to track motion of said user manipulable object and to command feedback forces to said user manipulable object, said interface apparatus comprising:

a user object being physically contacted and manipulable by a user and having at least one degree of freedom of movement;

a device microprocessor provided local to said interface apparatus and separate from said host computer and being controlled by software instructions stored in a memory device separate from said host computer, said microprocessor being coupled to said host computer by a serial interface bus and receiving host commands from said host computer on said first interface bus;

an actuator coupled to said user object for applying a force along said degree of freedom to said user object, wherein said actuator applies said force in response to microprocessor force commands produced by said device microprocessor;

a thermal sensor for detecting a temperature of said actuator, said thermal sensor providing a temperature signal to said microprocessor such that said microprocessor can deactivate said actuator when said temperature of said actuator rises above a predetermined threshold; and

a sensor coupled to said user object for detecting a position of said user object along said degree of freedom and for outputting a locative sensor signal which represents said position of said user manipulable object, said locative sensor signal being received by said host computer, and wherein said host computer modifies a displayed process in response to said locative sensor signal.

72. An interface apparatus for interfacing motion of a joystick with a host computer and enabling said host computer to track motion of said user manipulable object and to command feedback forces to said user manipulable object, said interface apparatus comprising:

a joystick being physically contacted and manipulable by a user and having at least one degree of freedom of movement with respect to a ground surface, wherein said joystick includes a safety break-away handle that breaks off from said interface apparatus when a force over a predetermined threshold is applied to said joystick;

a device microprocessor provided local to said interface apparatus and separate from said host computer and being controlled by software instructions stored in a memory device separate from said host computer, said microprocessor being coupled to said host computer by a serial interface bus and receiving host commands from said host computer on said first interface bus;

an actuator coupled to said user object for applying a force along said degree of freedom to said user object, wherein said actuator applies said force in response to microprocessor force commands produced by said device microprocessor; and

a sensor coupled to said user object for detecting a position of said user object along said degree of freedom and for outputting a locative sensor signal which represents said position of said user manipulable object, said locative sensor signal being, received by said host computer, and wherein said host computer modifies a displayed process in response to said locative sensor signal.

73. An interface apparatus as recited in claim 72 wherein said safety break-away handle is attached to said interface apparatus by a magnet.