Position sensor and actuating system

• US 20030090228A1
• Filed: 11/09/2001
• Published: 05/15/2003
• Est. Priority Date: 11/09/2001
• Status: Active Grant

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Wilkens, Dean
• Granted Patent: US 6,700,345 B2
• Time in Patent Office: Days
• US Class Current: 318/560
• CPC Class Codes: F16H 25/20 Screw mechanisms with automatic reversal F16H25/12
• CPC Class Codes: G05B 19/4062 Monitoring servoloop, e.g. overload of servomotor, loss of feedback or reference

Abstract

The present invention provides methods, systems, and apparati for fail passive error detection and control of a linear actuator recentering system. In an exemplary aspect of the present invention, linear actuator controls are designed to be fail passive. In one exemplary embodiment of the present invention, a recentering device is provided which receives a signal from an independent motion direction sensor and enables continuous monitoring of a recentering function, thereby detecting recentering control failures. In another exemplary embodiment, the present invention comprises a recentering motor control commutation device, an actuator movement direction sensor and an inverse commutation device for determining a centering polarity. The centering polarity is further provided to an aircraft control system which suitably provides continuous verification of the recentering commutation by comparison to linear actuator position determined by another sensor. In accordance with another exemplary embodiment, after detecting the failure of a control component, a brake is immediately set.

Claims

1. A method for providing fail passive protection for an actuator recentering system comprising the steps of:

determining a direction of motion of an actuator;

deriving a centering polarity signal based on the direction of motion of the actuator;

comparing the centering polarity signal with an actuator position signal; and

commanding the actuator to fail in a passive manner when the centering polarity signal is in disagreement with the actuator position signal.

2. The method of claim 1, the actuator being a linear actuator.

3. The method of claim 2, the actuator position signal being generated by a linear variable differential transformer.

4. The method of claim 2, the direction of motion being determined by an extend-retract Hall effect sensor.

5. The method of claim 2, the comparing step further comprising the step of receiving the centering polarity signal and the actuator position signal at an aircraft control system.

6. The method of claim 1, the commanding step further comprising the step of setting a brake.

7. The method of claim 4, the deriving step further comprising the steps of:

computing at least one recentering control signal based on the extend-retract Hall effect sensor signal, at least one motor feedback position signal, and a look up table; and

computing the center polarity signal based on the at least one recentering control signal, at least one motor feedback position signal, and a look up table.

8. The method of claim 7, wherein the deriving step is implemented using a program logic device.

9. The method of claim 8, the comparing step further comprising the step of receiving the centering polarity signal and the actuator position signal at an aircraft control system.

10. A fail passive linear actuator controller configured to perform the method of claim 7.

11. An aircraft flight control system for providing high integrity linear actuator recentering with fail passive control, the system comprising:

an aircraft control system configured to receive a linear actuator position signal representative of a position of the linear actuator, the aircraft control system further configured to received a centering polarity signal representative of a relative position of the linear actuator, the aircraft control system further configured to compare the linear actuator position signal to the centering polarity signal, and the aircraft control system further configured to cause a brake to be set if the linear actuator position signal disagrees with the centering polarity signal; and

a control unit configured to communicate with a motor position sensor, a linear actuator motion direction sensor, and the aircraft control system, the control unit further configured to drive the linear actuator motor, and wherein the control unit is configured to derive a centering polarity signal.

12. The system of claim 11, the motor configured to be a brushless motor.

13. The system of claim 11, wherein the communication from the motor position signal is at least one signal representative of a motor angle.

14. The system of claim 13, wherein the communication from the movement direction sensor is representative of a direction of rotation of the linear actuator.

15. The system of claim 14, the control unit further comprising an inverse motor commutation device configured to generate the centering polarity signal based on the motor angle and at least one recentering control signals.

16. The system of claim 15, the control unit further comprising a normal mode motor commutation and bridge switching device, and a recentering motor commutation and bridge switching device.

17. The system of claim 16, the inverse motor commutation device configured to receive signals from the motor position sensor and the recentering motor commutation and bridge switching device, and wherein the inverse motor commutation device is configured to provide a centering polarity feedback signal.

18. A fail passive control apparatus configured to cause a linear actuator to fail passively, the fail passive control apparatus comprising:

a recentering motor commutation device configured to receive a movement direction signal from a movement direction sensor and a motor position signal from a motor position sensor, wherein the recentering motor commutation device is configured to continuously generate a recentering control signal, and wherein the recentering control signal is calculated to return the linear actuator to a neutral position when a failure is detected;

an inverse motor commutation device, the inverse motor commutation device configured to receive the recentering control signal and motor position signal, and configured to provide a centering polarity signal indicating the relative position of the linear actuator to the neutral position, and wherein the centering polarity signal is based on the recenterting control signal and motor position signal; and

an aircraft control system in communication with the inverse motor commutation device, wherein the aircraft control system is configured to determine if an error exists by comparing the centering polarity signal and a direct linear actuator position signal, and whrein the aircraft control system is configured to set a brake if an error is detected.

19. The control apparatus of claim 18 the movement direction sensor further comprising an extend-retract Hall effect sensor.

20. The control apparatus of claim 18, a direct linear actuator sensor configured to provide the direct linear actuator position signal;

wherein the direct linear actuator sensor is a linear variable differential transformer.

21. The control apparatus of claim 18 wherein the neutral position is a center position.

22. The control apparatus of claim 18 wherein the inverse motor commutation device comprises a program logic device.