BRAKE OPERATION BUILT-IN TEST EQUIPMENT

• US 20100292889A1
• Filed: 05/14/2009
• Published: 11/18/2010
• Est. Priority Date: 05/14/2009
• Status: Abandoned Application

• Current Assignee: Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Prentice, Dale R., Cahill, Eric D.
• Application Number:
  US12/466,080
• Publication Number:
  US 20100292889A1
• Time in Patent Office: Days
• US Class Current: 701/31
• CPC Class Codes: B60T 2270/406 Test-mode; Self-diagnosis
• CPC Class Codes: B60T 8/1703 for aircrafts
• CPC Class Codes: B60T 8/885 using electrical circuitry
• CPC Class Codes: B64C 25/42 Arrangement or adaptation of brakes
• CPC Class Codes: B64F 5/60 Testing or inspecting aircraft components or systems

Abstract

A system, apparatus and method provide a means for testing operation of vehicle brake system. More particularly, a brake actuator is automatically commanded to engage a brake disk stack while the vehicle is in a benign state. An engagement force applied to the brake-disk stack by the actuator then is determined, and the engagement force is compared to a first threshold value. If the engagement force is within a predetermined range of the first threshold value, it is concluded that the brake system is operating normally, otherwise it is concluded that the brake system is operating abnormally.

Claims

1. A brake testing device for testing operation of a vehicle brake system, said brake testing device comprising logic configured to:

automatically command a brake actuator to apply a predetermined force to a brake-disk stack;

determine an engagement force applied to the brake-disk stack;

compare the engagement force to engagement criteria; and

conclude the brake system is operating normally if the engagement force is within a predetermined range of the engagement criteria, otherwise conclude that the brake system is operating abnormally.

2. The brake testing device according to claim 1, wherein the logic is further configured to:

determine an operational phase of the vehicle; and

command the brake actuator to engage the brake-disk stack only when the operational phase corresponds to a predetermined operational phase.

3. The brake testing device according to claim 1, wherein the logic is further configured to:

command the actuator to release the brake-disk stack after the engagement force is determined;

determine a residual force applied to the brake-disk stack after the actuator has been commanded to release the brake-disk stack;

compare the residual force to a release criteria; and

conclude the brake system is operating normally if the residual force is within a predetermined range of the release criteria, otherwise conclude that the brake system is operating abnormally.

4. The brake testing device according to claim 1, wherein the logic is further configured to output the results of each comparison.

5. The brake testing device according to claim 1, wherein the logic that determines the engagement force applied to the brake-disk stack includes logic configured to measure the force applied to the brake-disk stack.

6. The brake testing device according to claim 1, wherein the logic is further configured to:

detect an event corresponding to at least one of a brake command initiated via a brake input device, a wheel not at zero speed, or weight on the wheels; and

inhibit testing when the event is detected.

7. The brake testing device according to claim 1, wherein the logic is further configured to enable testing when a landing gear handle or a gear down lock sensor transitions from a landing gear up position to a landing gear down position.

8. The brake testing device according to claim 1, further comprising:

a first output for providing a command to the actuator; and

a first input for receiving data corresponding to at least one of the engagement force and the residual force.

9. The brake testing device according to claim 1, wherein the logic is implemented in a hardware circuit.

10. The brake testing device according to claim 1, further comprising a processor and memory, wherein the logic is stored in memory and executable by the processor.

11. The brake testing device according to claim 1, wherein the brake testing device is integrated within a brake system control unit (BSCU).

12. A brake system, comprising:

the brake testing device according to claim 1; and

a brake system control unit (BSCU) operatively coupled to the brake testing device.

13. The brake system according to claim 12, further comprising the actuator and brake-disk stack, the actuator operatively coupled to the brake testing device.

14. The brake system according to claim 12, further comprising at least one of a force transducer, position transducer, or pressure transducer operatively coupled to the brake testing device and to the actuator, said at least one transducer configured to provide data indicative of a force applied to the brake-disk stack by the actuator, a position of the actuator, or fluid pressure provided to the actuator.

15. A method for testing operation of vehicle brake system, said brake system including an actuator for selectively engaging a brake-disk stack so as to apply and release braking force on a rotatable member, the method comprising:

automatically commanding the actuator to apply a predetermined force to the brake disk stack;

determining an engagement force applied to the brake-disk stack;

comparing the engagement force to an engagement criteria; and

concluding the brake system is operating normally if the engagement force is within a predetermined range of the engagement criteria, otherwise concluding that the brake system is operating abnormally.

16. The method according to claim 15, wherein automatically commanding the actuator includes

determining an operational phase of the vehicle;

and

commanding the actuator only when the operational phase corresponds to a predetermined operational phase.

17. The method according to claim 15, further comprising:

commanding the actuator to release the brake disk stack after the engagement force is determined;

determining a residual force applied to the brake-disk stack after the actuator has been commanded to release the brake-disk stack;

comparing the residual force to a release criteria; and

concluding the brake system is operating normally if the residual force is within a predetermined range of the release criteria, otherwise concluding that the brake system is operating abnormally.

18. The method according to claim 15, wherein determining at least one of the engagement force or the residual force includes at least one of

using a force transducer to measure the respective force applied to the brake-disk stack,

using a position transducer infer the respective force applied to the brake disk stack from a position of force transducer to measure the respective force applied to the brake-disk stack from a position of the actuator, or

using a pressure transducer to infer the respective force applied to the brake disk stack from a fluid pressure provided to the actuator.

19. The method according to claim 15, further comprising inhibiting the test when at least one of a brake command is initiated via a brake input device, a wheel is not at zero speed, or weight on the wheels is detected.

20. The method according to claim 15, further comprising enabling the test when a landing gear handle or a gear down lock sensor indicates a transition from the landing gear being in the up position to the landing gear being in the down position.