Load optimized redundant flight control surface actuation system and method

• US 20080203224A1
• Filed: 02/27/2007
• Published: 08/28/2008
• Est. Priority Date: 02/27/2007
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Hanlon, Casey, Yount, Larry J., Johnson, Andy
• Granted Patent: US 8,033,509 B2
• Time in Patent Office: Days
• US Class Current: 244/99.5
• CPC Class Codes: B64C 13/42 having duplication or stand-by provisions
• CPC Class Codes: Y02T 50/40 Weight reduction

Abstract

An aircraft flight surface control system and method simultaneously provides the benefits of both an active/active system architecture and in active/standby system architecture. The system is preferably implemented using hydraulic actuator assemblies and electromechanical actuator assemblies coupled to the same flight control surface. During normal system operations the electromechanical actuator assemblies are energized to supply a relatively minimal force to associated flight control surfaces. In effect, the electromechanical actuators, although energized, may be pulled along by the associated hydraulic actuator assemblies, until needed. Thus, the electromechanical actuator assemblies are controlled in a manner that closely resembles the active/standby architecture.

Claims

1. An aircraft flight control surface actuation system, comprising:

an electromechanical actuator assembly adapted to be selectively supplied with electrical current and, upon receipt of the electrical current, to supply a force;

a hydraulic actuator assembly adapted to selectively receive a supply of hydraulic fluid and, upon receipt of the hydraulic fluid, to supply a force;

a hydraulic actuator control adapted to receive a position command signal and operable, in response thereto, to control the supply of hydraulic fluid to the hydraulic actuator assembly; and

an electromechanical actuator control operable to determine whether the hydraulic actuator assembly is supplying an adequate amount of force and, based in part on this determination, to control the electrical current supplied to, and thus the force supplied by, the electromechanical actuator assembly.

2. The system of claim 1, wherein:

the electromechanical actuator control is adapted to receive the position command signal and a position sensor signal representative of at least electromechanical actuator assembly position; and

the electromechanical actuator control is operable, in response to the position command signal and the position sensor signal, to make the determination as to whether the hydraulic actuator assembly is supplying an adequate amount of force.

3. The system of claim 2, wherein:

the electromechanical actuator control is further operable, in response to the position command signal and the position sensor signal, to determine a position error; and

the electromechanical actuator control makes the determination as to whether the hydraulic actuator assembly is supplying an adequate amount of force based in part on the determined position error.

4. The system of claim 1, wherein the electromechanical actuator control comprises:

a position error determination function, the position error determination function adapted to receive (i) the position command signal and (ii) a position sensor signal representative of at least electromechanical actuator assembly position and operable, in response to the position command signal and the position sensor signal, to (i) determine a position error and (ii) supply a position error signal representative thereof, the determined position error representative of whether the hydraulic actuator assembly is supplying an adequate amount of force; and

a current limit determination function, the current limit determination function coupled to receive the position error signal and operable, in response thereto, to determine a current limit value, the current limit value representative of a maximum magnitude of the electrical current that may be supplied to the electromechanical actuator assembly.

5. The system of claim 4, wherein:

the current limit determination function is further operable to supply a current limit signal representative of the determined current limit value; and

the electromechanical actuator control further comprises a current command determination function, the current command determination function coupled to receive the current limit signal and operable, based partially thereon, to supply a current command signal representative of a commanded electrical current to be supplied to the electromechanical actuator assembly.

6. The system of claim 5, wherein:

the electromechanical actuator control further comprises a current control loop, the current control loop coupled to receive (i) the current command signal and (ii) an actuator current sensor signal representative of the electrical current supplied to the electromechanical actuator assembly and operable, in response to the current command signal and the actuator current sensor signal, to energize the electromechanical actuator assembly with a voltage or duty cycle that causes the commanded electrical current to be supplied to the electromechanical actuator assembly.

7. The system of claim 5, wherein:

the electromechanical actuator control further comprises a speed control loop that includes the current command determination function, the speed control loop coupled to receive a speed command signal representative of a commanded actuator assembly movement speed and the speed sensor signal, and responsive thereto to (i) determine a speed error and (ii) supply a speed error signal representative of the determined speed error; and

the current command determination function is further coupled to receive the speed error signal and is operable to supply the current command signal based on the current limit signal and the speed error signal.

8. The system of claim 6, wherein:

the electromechanical actuator control further comprises a speed command determination function, the speed command determination function coupled to receive the position error signal and operable, in response thereto, to supply the speed command signal.

9. The system of claim 1, wherein:

the hydraulic actuator control is responsive to the position command signal to supply valve control signals; and

the hydraulic actuator assembly comprises a servo control valve coupled to receive the valve control signals and operable, in response thereto, to control receipt of the supply of hydraulic fluid.

10. The system of claim 1, wherein the electromechanical actuator assembly comprises:

an electric motor adapted to be selectively supplied with the electrical current and, upon receipt of the electrical current, to supply a rotational drive force; and

an actuator coupled to receive the rotational drive force from the electric motor and, in response thereto, to supply a force.

11. An aircraft, comprising:

a flight control surface coupled to receive a force from one or more sources and operable, upon receipt of the force, to move;

an electromechanical actuator assembly adapted to be selectively supplied with electrical current and, upon receipt of the electrical current, to supply a first force to the flight control surface;

a hydraulic actuator assembly adapted to selectively receive a supply of hydraulic fluid and, upon receipt of the hydraulic fluid, to supply a second force to the flight control surface;

a hydraulic actuator control adapted to receive a position command signal and operable, in response thereto, to control the supply of hydraulic fluid to the hydraulic actuator assembly; and

an electromechanical actuator control operable to determine whether the second force supplied by the hydraulic actuator assembly is an adequate amount of force and, based in part on this determination, to control the electrical current supplied to, and thus the first force supplied by, the electromechanical actuator assembly.

12. The system of claim 11, wherein:

the electromechanical actuator control is adapted to receive the position command signal and a position sensor signal representative of at least electromechanical actuator assembly position; and

the electromechanical actuator control is operable, in response to the position command signal and the position sensor signal, to make the determination as to whether the second force supplied by the hydraulic actuator assembly is an adequate amount of force.

13. The system of claim 12, wherein:

the electromechanical actuator control is further operable, in response to the position command signal and the position sensor signal, to determine a position error; and

the electromechanical actuator control makes the determination as to whether the second force supplied by the hydraulic actuator assembly is an adequate amount of force based on the determined position error.

14. The system of claim 11, wherein the electromechanical actuator control comprises:

a position error determination function, the position error determination function adapted to receive (i) the position command signal and (ii) a position sensor signal representative of at least electromechanical actuator assembly position and operable, in response to the position command signal and the position sensor signal, to (i) determine a position error and (ii) supply a position error signal representative thereof, the determined position error representative of whether the hydraulic actuator assembly is supplying an adequate amount of force; and

a current limit determination function, the current limit determination function coupled to receive the position error signal and operable, in response thereto, to determine a current limit value, the current limit value representative of a maximum magnitude of the electrical current that may be supplied to the electromechanical actuator assembly.

15. The system of claim 14, wherein:

the current limit determination function is further operable to supply a current limit signal representative of the determined limit value; and

the electromechanical actuator control further comprises a current command determination function, the current command determination function coupled to receive the current limit signal and operable, based partially thereon, to supply a current command signal representative of a commanded electrical current to be supplied to the electromechanical actuator assembly.

16. The system of claim 15, wherein:

the current limit determination function is further coupled to receive a speed error signal and is operable to supply a current command signal based on the current limit signal and the speed error signal; and

the electromechanical actuator control further comprises;

a speed command determination function coupled to receive the position error signal and operable, in response thereto, to supply a speed command signal representative of a commanded actuator assembly movement speed,

a speed control loop that includes the current limit determination function, the speed control loop coupled to receive the speed command signal and the speed sensor signal, and responsive thereto to supply the speed error signal to the current limit determination function, and

a current control loop coupled to receive (i) the current command signal and (ii) an actuator current sensor signal representative of the electrical current supplied to the electromechanical actuator assembly and operable, in response to the current command signal and the actuator current sensor signal, to energize the electromechanical actuator assembly with a voltage or duty cycle having a magnitude that causes the commanded electrical current to be supplied to the electromechanical actuator assembly.

17. A method of moving a flight control surface having a hydraulic actuator assembly and an electromechanical actuator assembly coupled thereto, the method comprising the steps of:

supplying a force to the flight control surface from the hydraulic actuator assembly;

supplying a force to the flight control surface from the electromechanical actuator assembly;

determining whether the hydraulic actuator assembly is supplying an adequate amount of force to the flight control surface; and

controlling the force supplied from the electromechanical actuator assembly to the flight control surface based partially on the determination of whether the hydraulic actuator assembly is supplying an adequate amount of force to the flight control surface.

18. The method of claim 17, further comprising:

supplying a position command to both the hydraulic actuator assembly and the electromechanical actuator assembly;

determining a position of at least the electromechanical actuator assembly;

comparing the position command to the determined position to determine a position error; and

determining whether the hydraulic actuator assembly is supplying sufficient force to the flight control surface based on the determined position error.

19. The method of claim 17, further comprising:

determining a current limit value based on the determined position error, the current limit value representative of a maximum magnitude of electrical current that may be supplied to the electromechanical actuator assembly, and

limiting the electrical current supplied to the electromechanical actuator assembly to the current limit value.

20. The method of claim 19, wherein:

when the hydraulic actuator assembly is supplying sufficient force to the flight control surface, the electrical current supplied to the electromechanical actuator assembly is at least of a magnitude to maintain at least a portion of the electromechanical actuator assembly above a predetermined temperature.