Position control system for cross coupled operation of fly-by-wire control columns

• US 8,814,103 B2
• Filed: 07/28/2010
• Issued: 08/26/2014
• Est. Priority Date: 07/28/2010
• Status: Active Grant

• Current Assignee: Woodward MPC, Inc.
• Original Assignee: Woodward MPC, Inc.
• Inventors: Szulyk, Zenon P., Jayaraman, Ganga P., Frayman, Charles C., Dyra, Brian P., Stachniak, Darryl S.
• Primary Examiner(s): Xavier, Valentina
• Application Number:
  US12/844,867
• Publication Number:
  US 20120025029A1
• Time in Patent Office: 1,490 Days
• Field of Search: 244220-223, 244/228, 244/229, 244/234, 244/236, 244194-196, 244/99.2, 244/99.4
• US Class Current: 244/223
• CPC Class Codes: G05G 11/00 Manually-actuated control mechanisms provided with two or more controlling members co-operating with one single controlled member
• CPC Class Codes: G05G 5/03 Means for enhancing the operator's awareness of arrival of the controlling member at a command or datum position; Providing feel, e.g. means for creating a counterforce arrangements for indicating the position of the controlling member G05G1/015

Abstract

A aircraft control system is provided that provides tactile feedback between control columns of the aircraft relating to discrepancies in the control inputs to the sticks of the respective control columns. In one implementation, the sticks each have an associated feedback assembly that is adjustable relative to mechanical ground to adjust the feedback profile applied to the corresponding stick. The position of each feedback assembly is adjusted based on a relative displacement between the other feedback assembly and its corresponding stick to provide active feedback relating to the control of the other control column.

Claims

1. An aircraft control system comprising:

a first feedback assembly movable relative to a mechanical ground;

a first stick movable relative to the mechanical ground and the first feedback assembly, wherein;

a) a first stick position is the position of the first stick relative to the mechanical ground;

b) a first feedback position is the position of the first feedback assembly relative to the mechanical ground; and

c) a first relative error is the first stick position minus the first feedback position; and

a second feedback assembly movable relative to the mechanical ground;

a second stick movable relative to the mechanical ground and the second feedback assembly, wherein;

a) a second stick position is the position of the second stick relative to the mechanical ground;

b) a second feedback position is the position of the second feedback assembly relative to the mechanical ground; and

c) a second relative error is the second stick position minus the second feedback position; and

a control arrangement including a cross-coupled mode in which the control arrangement provides first and second feedback position commands to position the first and second feedback assemblies wherein the first feedback position command is equal to the second relative error and the second feedback position command is equal to the first relative error.

2. The aircraft control system of claim 1, wherein the first feedback assembly provides passive tactile feedback to the first stick when the first stick is transitioned from a first feedback neutral position of the first feedback assembly;

and

wherein the second feedback assembly provides passive tactile feedback to the second stick when the second stick is transitioned from a second feedback neutral position of the second feedback assembly.

5. The aircraft control system of claim 2, wherein the first feedback assembly includes a first gimbal arrangement that provides the passive tactile feedback to the first stick and that defines the first feedback neutral position, the first feedback assembly further including a first actuator for adjusting the position of the first feedback neutral position relative to the mechanical ground;

and

wherein the second feedback assembly includes a second gimbal arrangement that provides the passive tactile feedback to the second stick and that defines the second feedback neutral position, the second feedback assembly further including a second actuator for adjusting the position of the second feedback neutral position relative to the mechanical ground.

6. The aircraft control system of claim 5, wherein the first gimbal arrangement and the first stick are pivotally affixed to the mechanical ground for pivotal movement about a first common axis, wherein the second gimbal arrangement and the second stick are pivotally affixed to the mechanical ground for pivotal movement about a second common axis.

7. The aircraft control system of claim 5, wherein the first feedback assembly is configured such that failure of the first actuator does not prevent movement of the first stick relative to the mechanical ground and the first feedback assembly and wherein the second feedback assembly is configured such that failure of the second actuator does not prevent movement of the second stick relative to the mechanical ground and the second feedback assembly.

8. The aircraft control system of claim 1, wherein the control arrangement also includes a priority mode in which a selected one of the first or second sticks has its feedback assembly maintained in a fixed position relative to mechanical ground and the control arrangement is configured to adjust the position of the feedback assembly of the non-selected one of the first and second sticks based on a difference between the first and second stick positions.

9. The aircraft control system of claim 8, wherein when the first stick is the selected one of the sticks, the control arrangement controls the second feedback position such that the second feedback position is equal to the second feedback position plus the first stick position minus the second stick position and when the second stick is the selected one of the sticks, the control arrangement controls the first feedback position such that the first feedback position is equal to the first feedback position plus the second stick position minus the first stick position.

10. The aircraft control system of claim 1, wherein the first feedback assembly and the first stick are pivotally affixed to the mechanical ground for pivotal movement about a first common axis, wherein the second feedback assembly and the second stick are pivotally affixed to the mechanical ground for pivotal movement about a second common axis;

and wherein the first stick position and first feedback position are measured in degrees about the first common axis, wherein the second stick position and second feedback position are measured in degrees about the second common axis.

3. An aircraft control system comprising:

a first feedback assembly movable relative to a mechanical ground;

a first stick movable relative to the mechanical ground and the first feedback assembly, wherein;

a) a first stick position is the position of the first stick relative to the mechanical ground;

b) a first feedback position is the position of the first feedback assembly relative to the mechanical ground; and

c) a first relative error is the first stick position minus the first feedback position; and

a second feedback assembly movable relative to the mechanical ground;

a second stick movable relative to the mechanical ground and the second feedback assembly, wherein;

a) a second stick position is the position of the second stick relative to the mechanical ground;

b) a second feedback position is the position of the second feedback assembly relative to the mechanical ground;

c) a second relative error is the second stick position minus the second feedback position; and

a control arrangement including a cross-coupled mode in which the control arrangement provides first and second feedback position commands to position the first and second feedback assemblies wherein the first feedback position command is equal to the second relative error and the second feedback position command is equal to the first relative error;

wherein the first feedback assembly provides passive tactile feedback to the first stick when the first stick is transitioned from a first feedback neutral position of the first feedback assembly;

wherein the second feedback assembly provides passive tactile feedback to the second stick when the second stick is transitioned from a second feedback neutral position of the second feedback assembly; and

wherein the first feedback assembly includes a first cam surface defining the first feedback neutral position and a first resistance arrangement, the first stick includes a first cam follower, wherein the first resistance arrangement increasingly resists movement of the first cam follower from the first feedback neutral position to provide the passive tactile feedback; and

wherein the second feedback assembly includes a second cam surface defining the second feedback neutral position and a second resistance arrangement, the second stick includes a second cam follower, wherein the second resistance arrangement increasingly resists movement of the second cam follower from the second feedback neutral position to provide the passive tactile feedback.

4. The aircraft control system of claim 3, wherein the first and second feedback resistance arrangements are provided by spring and damper arrangements;

and

the first and second cam surfaces are generally V-shaped with the first cam follower positioned within the V-shape of the first cam surface and the second cam follower is positioned within the V-shape of the second cam surface, wherein the first and second feedback neutral positions are when the first and second cam followers contact both sides of the V-shaped surfaces.

11. An aircraft control system comprising:

a first stick, and

a first feedback arrangement providing a passive first feedback profile for the first stick relative to mechanical ground, at least a portion of the first feedback arrangement being movable relative to the mechanical ground and the first stick for adjusting the first feedback profile; and

a first actuator coupled to the first passive feedback arrangement for adjusting the position of the first passive feedback arrangement relative to the mechanical ground for adjusting the first feedback profile;

a second feedback arrangement providing a passive second feedback profile for the second stick relative to mechanical ground, at least a portion of the second feedback arrangement being movable relative to the mechanical ground and the second stick for adjusting the second feedback profile;

a second actuator for adjusting the position of the second passive feedback arrangement relative to the mechanical ground for adjusting the second feedback profile; and

a feedback controller arrangement configured to control the first actuator for adjusting the position of the first passive feedback arrangement relative to the mechanical ground, the feedback controller arrangement is configured to control the second actuator for adjusting the position of the second passive feedback arrangement relative to the mechanical ground.

12. The air craft control system of claim 11, wherein the second feedback arrangement defines a feedback neutral position and wherein the feedback controller arrangement is configured to adjust the position of the first feedback arrangement to a position equal to the position of the second stick relative to the second feedback neutral position.

13. The air craft control system of claim 11, wherein the feedback controller arrangement is configured to control the second actuator to adjust the position of the second feedback arrangement to provide a biasing force biasing the second stick toward a same absolute position relative to the mechanical ground as the absolute position of the first stick relative to the mechanical ground.

14. The air craft control system of claim 11, wherein the first stick has a first stick position relative to the mechanical ground and the first feedback arrangement has a first feedback position relative to the mechanical ground;

wherein the second stick has a second stick position relative to the mechanical ground, and

wherein the feedback controller arrangement is configured to control the first actuator for adjusting the position of the first passive feedback arrangement such that a current first feedback position of the first feedback assembly is equal to a prior feedback position of the first feedback assembly plus a difference between the first stick position and the second stick position.

15. The air craft control system of claim 11, wherein the second stick has a second stick position relative to the mechanical ground, and

wherein the first stick has a first stick position which is the position of the first stick relative to the mechanical ground and the feedback controller arrangement is configured to control the first actuator to oscillate back and forth the first feedback arrangement when the second stick position is not equal to the first stick position.

16. A method of providing feedback to a control stick of an aircraft comprising the steps of:

sensing a first stick position which is the position of a first stick relative to a mechanical ground;

sensing a first feedback position which is the position of a first feedback assembly relative to the mechanical ground;

determining a first relative error which is the first stick position minus the first feedback position; and

adjusting, using a control arrangement, a second feedback position, which is the position of a second feedback assembly of a second stick relative to the mechanical ground, such that the second feedback position is equal to the first relative error; and

further comprising the steps of;

sensing a second stick position which is the position of the second stick relative to the mechanical ground;

sensing the second feedback position;

determining a second relative error which is the second stick position minus the second feedback position; and

adjusting, using the control arrangement, the first feedback position such that the first feedback position is equal to the second relative error.

17. The method of claim 16, wherein the steps of adjusting the first and second feedback positions occurs substantially continuously such that when one of the first and second sticks is moved to a different position relative to mechanical ground than the other stick, at least one of the first and second feedback positions are adjusted to cause the first and second sticks to remain substantially at a same relative position relative to the mechanical ground.

18. The method of claim 17, further comprising the step of passively biasing the first stick when the first stick is displaced from a feedback neutral position of the first feedback assembly and passively biasing the second stick when the second stick is displaced from a feedback neutral position of the second feedback assembly.

19. The method of claim 16, further comprising the step of initiating a priority mode to prioritize the second stick, and performing the following steps when in the priority mode:

sensing the first stick position;

sensing the first feedback position;

sensing a second stick position which is the position of a second stick relative to the mechanical ground;

determining a first stick relative error which is the second stick position minus the first stick position; and

adjusting the first feedback position by adding the first stick relative error to the first feedback position.

20. The method of claim 19, further comprising the step of always maintaining the second feedback position fixed when there is a difference between the first and second stick positions.

21. The method of claim 16, further comprising reciprocally vibrating the first stick by reciprocally adjusting the first feedback position when the first stick position is not equal to a second stick position.