Apparatus and method for controlling a force-activated controller

• US 20050080495A1
• Filed: 11/06/2002
• Published: 04/14/2005
• Est. Priority Date: 11/06/2001
• Status: Active Grant

• Current Assignee: Bombardier Incorporated
• Original Assignee: Bombardier Incorporated
• Inventors: Tessier, Claude, Martineau, Jonathan
• Granted Patent: US 8,050,780 B2
• Time in Patent Office: Days
• US Class Current: 700/63
• CPC Class Codes: B64C 13/0421 control sticks for primary flight controls
• CPC Class Codes: B64C 13/503 Fly-by-Wire
• CPC Class Codes: G05D 1/82 Limited authority control, e.g. enforcing a flight envelope limitation of acceleration or structural stress G05D1/83
• CPC Class Codes: G05D 2105/22 of humans
• CPC Class Codes: G05D 2109/20 Aircraft, e.g. drones

Abstract

A servo controlled system is disclosed for providing simulated feel equivalent to that of traditional mechanical hand controllers using servomotors. Position and force sensor signals are processed and used in a feedback loop that controls the motor mechanically connected to the stick. The overall feedback loop is comprised of a low-level motor feedback loop, and high-level force feel loop. The two loops have associated performance parameters that can be specified independently. The high-level feel force loop is comprised of a static and dynamic performance components. Static and dynamic performance components can be specified independently. The system allows variable and/or additional force cues to be specified externally to the system and felt by the operator. The system also allows external signal to backdrive die stick to follow a specified motion. The control framework permits the electronic coupling of the motion and applied forces of pilot and co-pilots in a dual arrangement while retaining the above-mentioned features. It also allows asymmetric force feel gradients to be implemented for each stick, or for a stick relative to a second one. A zero breakout or detent can be provided at the stick null displacement. For cross-coupled sticks, the detent can be shared as in a mechanically cross-coupled system, implemented independently on each slick, or any combination of these two. The control framework also provides the simulation of mechanical compliance in the cross-coupling of the two sticks in case of a jam or of force fight between the pilots, and automatic de-coupling of the sticks.

Claims

1. A control system comprising:

a control member,

drive means for driving movement of the control member,

determining means for receiving the value of a desired displacement for said control member and determining a required movement for said control member based on said desired displacement, and

a controller for controlling said drive means in response to said determined movement.

2. A control system as claimed in claim 1, including a static performance model defining the relationship between the desired displacement and another parameter.

3. A control system as claimed in claim 2, wherein said other parameter is a force.

4. A control system as claimed in any preceding claim 1, wherein said determining means includes a predetermined relationship between the desired displacement and movement for the control member, and is capable of determining a series of values of displacement for the control member between its initial position and the desired displacement.

5. A control system as claimed in claim 4, wherein said determining means is adapted to determine a series of values of position for said control member as a function of time.

6. A control system as claimed in claim 4, wherein said determining means is adapted to determine a series of values of velocity for said control member as a function of time.

7. A control system as claimed in claim 4, wherein said determining means is adapted to determine a series of values of acceleration for said control member as a function of time.

8. A control system as claimed in claim 2, further comprising a controller for varying the relationship between the desired displacement and said other parameter.

9. A control system as claimed in claim 4, further comprising control means for varying the predetermined relationship between said desired displacement and movement for said control member.

10. A control system as claimed in claim 8, wherein said controller is adapted to vary said relationship in response to a condition of a system being controlled by said control system.

11. A control system as claimed in claim 9, wherein said control means is adapted to vary said relationship in response to a condition of a system being controlled by said control system.

12. An apparatus for controlling movement of a force-activated control member, comprising:

a control member, a driver for driving movement of said control member, trajectory determining means for receiving a signal indicative of the direction for movement for said control member and for determining a trajectory for said control member based on said signal, and

a controller for comparing the direction for movement for said control member indicated by said first signal with a direction indicated by a second signal, and for varying the trajectory determined by said trajectory determining means based on said comparison, and wherein said driver is arranged to drive said control member based on the trajectory modified by said controller.

13. An apparatus as claimed in claim 12, wherein said controller is adapted to vary said trajectory if the direction indicated by said first signal is opposite to that indicated by said second signal.

14. An apparatus as claimed in claim 12, further comprising a sensor for sensing a force applied to a second control member by an operator and for passing a signal indicative of said force as said second signal to said controller.

15. An apparatus as claimed in claim 12, further comprising a sensor for sensing a force applied to said control member and for passing a signal indicative of said force to said controller as said second signal.

16. An apparatus as claimed in claim 15, wherein said first signal is generated by an automatic control system for controlling movement of said control member.

17. An apparatus as claimed in claim 16, wherein said automatic control system comprises a computer.

18. An apparatus as claimed in claim 12, wherein said first signal is indicative of a first force and said second signal is indicative of a second force, and said controller is adapted not to vary said trajectory if the difference in the magnitudes of said forces or the magnitude of the lesser of the forces is below a predetermined threshold.

19. An apparatus as claimed in claim 12, further comprising changing means for changing the signal which is used by said trajectory determining means for determining said trajectory from said first signal to said second signal.

20. An apparatus as claimed in claim 19, wherein said first signal is indicative of a first force and said second signal is indicative of a second force, and wherein said changing means is adapted to change the signal from said first signal to said second signal if said second force exceeds a predetermined threshold.

21. An apparatus as claimed in claim 20, wherein said changing means is adapted to gradually change the signal from said first signal to said second signal over a predetermined period of time.

22. An apparatus as claimed in claim 21, wherein said changing means is adapted to change said signal by gradually reducing the first signal to zero and gradually increasing the value of said second signal from zero.

23. An apparatus as claimed in claim 22, wherein said changing means is adapted to reduce said first signal and increase said second signal substantially simultaneously.

24. An apparatus for controlling movement of a control member, comprising:

a driver for driving movement of a control member,

a conditioner for receiving an input signal indicative of a force, said conditioner defining a first relationship between an input force in one direction and an output force and defining a second relationship between an input force in the opposite direction and an output force, said first relationship being different to said second relationship,

trajectory determining means for determining a trajectory for said control member based on said output force determined by said conditioner, and wherein said driver is arranged to drive said control member based on said determined trajectory.

25. An apparatus as claimed in claim 24, further comprising sensor means for sensing a force applied to the control member by an operator, and for transmitting a signal indicative of said applied force to said conditioner as said input signal.

26. An apparatus as claimed in claim 24, further comprising a second conditioner having an input for receiving a signal indicative of a force, said second conditioner defining a relationship between an output force and an input force, summing means for summing the output force from said first conditioner and the output force from said second conditioner and means for passing a signal based on said summed forces to said trajectory determining means.

27. An apparatus as claimed in claim 26, further comprising a sensor for sensing a force applied to a second control member by an operator and for transmitting a signal indicative of the sensed force as said input signal to said second conditioner.

28. An apparatus as claimed in claim 26, wherein the relationship defined by said second conditioner comprises a first relationship between an output force and an input force in one direction and a second relationship between an output force and an input force in the opposite direction, wherein said first relationship defined by said second conditioner is different from said second relationship.

29. An apparatus as claimed in claim 28, wherein said first relationship scales said input force by a predetermined factor to provide said output force and said second relationship scales said input force by a second, different factor to provide said output force.

30. An apparatus as claimed in claim 24, wherein said first relationship defined by said first conditioner scales said input force by a first predetermined factor to provide said output force, and said second relationship scales said input force by a second, different predetermined factor to provide said output force.

31. An apparatus as claimed in claim 24, further comprising means for adding an additional force to the force provided from said conditioner to said trajectory determining means.

32. An apparatus for controlling movement of a control member, comprising:

a driver for driving movement of a control member, a conditioner for receiving an input signal indicative of a force, said conditioner defining a relationship between an input force and an output force in which the output force is substantially zero or a constant similar value over a predetermined range of input force values,

trajectory determining for determining a trajectory for said control member based on the output force determined by said conditioner, and wherein said driver is arranged to drive movement of said control member based on said determined trajectory.

33. An apparatus as claimed in claim 32, further comprising sensor means for sensing a force applied to the control member by an operator, and for transmitting a signal indicative of said applied force to said conditioner as said input signal.

34. An apparatus as claimed in claim 32, further comprising a second conditioner defining a relationship between an input force and an output force, in which said output force is substantially zero or a constant finite value over a predetermined range of input force, summing means for summing the output force from said first conditioner and the output force from said second conditioner, and means for passing a signal based on said summed forces to said trajectory determining means.

35. An apparatus as claimed in claim 34, further comprising a sensor for sensing a force applied to a second control member by an operator, and for transmitting a signal indicative of the sensed force as said input signal to said second conditioner.

36. An apparatus as claimed in claim 32, further comprising means for adding an additional force to the force provided from the or each said conditioner to said trajectory determining means.

37. An apparatus as claimed in claim 35, further comprising a third conditioner defining a relationship between an input force and an output force, wherein said third conditioner is adapted to receive said signal indicative of the summed forces from said summing means and determining an output force based on said input signal for said trajectory determining means.

38. An apparatus as claimed in claim 37, further comprising means for adding an additional force to the output force provided from said third conditioner to said trajectory determining means.

39. An apparatus as claimed in claim 32, wherein said trajectory determining means comprises displacement determining means for determining a commanded displacement for said control member from the force signal input thereto.

40. An apparatus as claimed in claim 39, wherein said trajectory determining means further comprises a trajectory generator for generating said desired trajectory from said commanded displacement.

41. A controller for controlling a driver for driving movement of a control member, comprising:

input means for receiving a signal indicative of a force applied to a control member by an operator, and

a compensator for varying the force applied by said driver to said control member in response to said signal to oppose the force applied to said control member by said operator.

42. A controller as claimed in claim 41, further comprising means for causing said driver to drive movement of said control member in response to another signal.

43. A controller as claimed in claim 42, wherein said means for causing is adapted to drive movement of said control member in response to a signal indicative of a desired movement for said control member.

44. A controller as claimed in claim 43, wherein said means for causing is adapted to drive movement of said control member in response to a signal containing at least one of a series of defined positions for said control member, a velocity for said control member as a function of time and an acceleration for said control member as a function of time.

45. A controller as claimed in claim 41, further comprising generator means for generating a drive signal for causing said driver to drive movement of said control member in response to a trajectory control signal, and wherein said compensator is adapted to control said generator such that said drive signal substantially removes the effect of a force applied to said control member by an operator on movement of said control member.

46. An apparatus for controlling coupling between first and second force-activated control members, comprising a first sensor for sensing a value of a parameter indicative of a force when a force is applied to said first control member, a second sensor for sensing a value of a parameter indicative of a force when a force is applied to said second control member, coupling means for coupling motion of one of said first and second control members to the other said control member, detecting means for detecting a difference in the direction of said forces, and coupling control means for permitting differential displacement between said first and second control members if the lesser of said values exceeds a predetermined value.

47. An apparatus as claimed in claim 46, wherein said coupling controller is arranged to permit said differential displacement if the force applied to said first control member is directed away from the force applied to said second control member.

48. An apparatus as claimed in claim 46, wherein said coupling controller is adapted to disable said coupling means to decouple said first and second control members when said lesser value exceeds a predetermined value.

49. An apparatus as claimed in claim 46, further comprising means for determining the value of differential displacement between said first and second control members depending on the lesser value of the sensed force.

50. An apparatus as claimed in claim 49, further comprising a model defining the relationship between the lesser value of said sensed force and differential displacement.

51. An apparatus as claimed in claim 49, further comprising a model defining the motion of one of said first and second control members based on the determined differential displacement.

52. An apparatus as claimed in claim 46, further comprising summing means for summing values of forces based on said sensed values, and displacement determining means for determining a displacement for at least one of said first and second control members based on the summed values.

53. An apparatus as claimed in claim 52, further comprising motion determining means for determining the motion of at least one of said first and second controllers based on said determined displacement.

54. An apparatus as claimed in claim 52, wherein said motion determining means comprises a model defining the motion of at least one of said first and second controllers.

55. An apparatus as claimed in claim 54, further comprising determining means for determining a motion of at least one of said first and second control members based on a determined differential displacement, and wherein said motion determining means defines a different motion than the motion determining means that determines motion of at least one of said first and second control members based on the determined displacement.

56. An apparatus as claimed in claim 54, further comprising means for preventing a value of force based on the sensed value of at least one of said first and second sensors from being summed with the other value.

57. An apparatus as claimed in claim 56, wherein said preventing means is arranged to reduce the value to be prevented from being summed over a period of time so as to prevent instantaneous decoupling of said first and second controllers.

58. An apparatus as claimed in claim 56, wherein said preventing means is arranged to restore coupling between said first and second controllers when the lesser of said sensed values decreases below a predetermined value.

59. An apparatus as claimed in claim 58, wherein said preventing means is arranged to restore coupling between said first and second controllers over a period of time such as to prevent instantaneous re-coupling of said first and second controllers.

60. An apparatus as claimed in claim 46, including means for preventing at least one of differential displacement and decoupling of said first and second control members until a differential force is applied to said controllers for a predetermined length of time.

61. An apparatus for controlling an actuator, comprising a control member for receiving an applied force from an operator, a trajectory generator for receiving a commanded displacement and for generating a signal therefrom indicative of a desired trajectory for said control member, and means for feeding said signal to an actuator controller for controlling said actuator in response to said signal.

64. An apparatus as claimed in claim 61, further comprising drive means for driving movement of said control member in response to said desired trajectory signal.

65. An apparatus as claimed in claim 61, wherein said trajectory generator is adapted to output as said desired trajectory at least one of the desired position, velocity and acceleration of said control member as a function of time.

66. An apparatus as claimed in claim 61, further comprising a sensor for sensing at least one of the position, velocity and acceleration of said control member, and means for comparing the sensed parameter with the value of said corresponding parameter in said desired trajectory signal.

67. An apparatus as claimed in claim 66, wherein said comparison means is adapted to generate a signal if the difference between the value of said sensed parameter and the parameter output from said trajectory generator exceeds a predetermined threshold.

68. An apparatus as claimed in claim 67, further comprising means for feeding the sensed parameter signal to the actuator controller, and signal selector means responsive to the signal from said comparison means for selecting which of said desired trajectory signal and said sensed parameter signal is used by said actuator controller to control said actuator.

69. An apparatus as claimed in claim 61, further comprising drive means for driving movement of said control member and wherein said trajectory generator is capable of transmitting a first desired trajectory signal to said drive controller and a second, different desired trajectory signal to said actuator controller.

70. An apparatus as claimed in claim 69, wherein said desired trajectory signal is selected as the signal used by the actuator unless a fault is detected that may effect the validity of said desired trajectory signal.

62. An apparatus for controlling an actuator, comprising a control member for receiving a force from an operator,

a trajectory generator for receiving a commanded displacement for said control member and for generating a signal indicative of a desired trajectory for said control member, and an actuator controller for receiving said signal and adapted to control an actuator in response to said signal.

63. An apparatus as claimed in claim 62, comprising means for generating said commanded displacement based on a force applied to said control member.

71. An apparatus for controlling movement of a control member comprising drive means for driving movement of said control member, determining means for receiving the value of a commanded displacement for said control member and for generating from said commanded displacement a series of positions for said control member, and

a controller for controlling said drive means in response to said series of positions.