Electromechanical actuator including redundant, dissimilar position feedback

• US 20070051847A1
• Filed: 09/08/2005
• Published: 03/08/2007
• Est. Priority Date: 09/08/2005
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Geck, Kellan, Evans, Paul, Quitmeyer, James
• Granted Patent: US 7,560,888 B2
• Time in Patent Office: Days
• US Class Current: 244/99.200
• CPC Class Codes: F16H 2025/2081 Parallel arrangement of drive motor to screw axis
• CPC Class Codes: F16H 25/2015 Means specially adapted for stopping actuators in the end position; Position sensing means
• CPC Class Codes: F16H 25/205 comprising alternate power paths, e.g. for fail safe back-up
• CPC Class Codes: H02K 16/00 Machines with more than one rotor or stator machines for transmitting mechanical power from a driving shaft to a driven shaft and comprising structurally interrelated motor and generator parts H02K51/00; permanent magnet machines with multiple rotors or stators relatively rotated for vectorially combining the excitation fields or the armature voltages H02K21/029
• CPC Class Codes: H02K 7/06 Means for converting reciprocating motion into rotary motion or vice versa
• CPC Class Codes: Y10T 74/18576 including screw and nut

Abstract

A relatively small, lightweight actuator includes a plurality of motors, an actuation element, a translation member, and a plurality of position sensors. The motors each supply a drive force to the actuation member, causing it to rotate. The translation member is configured, upon rotation of the actuator, to translate to a position. The position sensors sense the translational position of the translation member and the rotational position of each motor. The actuator is relatively small, lightweight, and can withstand the relatively severe environmental conditions and relatively significant levels of vibration and shock associated with many aerospace applications.

Claims

1. An actuator assembly, comprising:

a plurality of motors, each motor adapted to receive electrical drive power and configured, upon receipt thereof, to supply a drive force;

an actuation member coupled to receive the drive force from each of the motors and configured, upon receipt thereof, to rotate;

a translation member disposed adjacent the actuation member and configured, upon rotation of the actuation member, to translate to a position;

a first position sensor mounted within the actuation member and configured to sense the position of the translation member and supply a first position signal representative thereof; and

a second position sensor coupled to receive the drive force from at least one of the plurality of motors and operable, upon receipt thereof, to supply a second position signal representative of the position of the translation member.

2. The actuator assembly of claim 1, further comprising:

a third position sensor coupled to receive the drive force from at least one of the plurality of motors and operable, upon receipt thereof, to supply a third position signal representative of the position of the translation member.

3. The actuator assembly of claim 1, wherein:

the first position sensor comprises a linear variable differential transformer (LVDT); and

the second and third position sensors each comprise a resolver.

4. The actuator assembly of claim 3, wherein:

the second and third position sensors are each coupled to receive the drive force supplied from different motors.

5. The actuator assembly of claim 3, wherein:

the LVDT includes a differential transformer having primary windings and secondary windings, and a movable slug disposed between the primary and secondary windings;

the differential transformer is disposed within the actuation member; and

the movable slug is coupled to, and movable with, the translation member.

6. The actuator assembly of claim 1, wherein the translation member further includes a first end and a second end, and wherein the actuator assembly further comprises:

a rod end assembly coupled to the translation member second end, the rod end assembly configured to couple the translation member to an aerospace component.

7. The actuator assembly of claim 1, wherein each of the motors is a brushless DC motor.

8. The actuator assembly of claim 1, further comprising:

an actuator housing assembly,

wherein each of the motors is mounted on the actuator assembly housing.

9. The actuator assembly of claim 1, further comprising:

a gear assembly coupled between each of the motors and the actuation member, the gear assembly configured to receive the rotational drive force supplied by each of the motors and transfer the rotational drive force to the actuation member.

10. The actuator assembly of claim 9, wherein the gear assembly is configured as a torque summed gear train.

11. An actuator assembly, comprising:

a housing;

a plurality of motors mounted on the housing, each motor configured to supply a rotational drive force;

a ballscrew rotationally mounted within the housing and including at least an inner surface and an outer surface, the ballscrew inner surface defining a sensor cavity, the ballscrew outer surface having one or more ball grooves formed thereon, the ballscrew adapted to receive the rotational drive force from each of the motors and configured, in response thereto, to rotate;

a ballnut disposed at least partially within housing and mounted against rotation, the ballnut disposed at least partially around the ballscrew and including at least an inner surface and an outer surface, the ballnut inner surface having one or more ball grooves formed thereon;

a plurality of balls disposed within the one or more ballnut ball grooves and at least selected ones of the one or more ballscrew ball grooves, whereby rotation of the ballscrew causes translation of the ballnut to a position;

a first position sensor disposed at least partially within the ballscrew cavity, the first position sensor configured to sense the position of the ballnut and supply a position signal representative thereof; and

a second position sensor coupled to receive the drive force from at least one of the plurality of motors and operable, upon receipt thereof, to supply a second position signal representative of the position of the ballnut.

12. The actuator assembly of claim 11, further comprising:

a third position sensor coupled to receive the drive force from at least one of the plurality of motors and operable, upon receipt thereof, to supply a third position signal representative of the position of the translation member.

13. The actuator assembly of claim 11, wherein:

the first position sensor comprises a linear variable differential transformer (LVDT); and

the second and third position sensors each comprise a resolver.

14. The actuator assembly of claim 13, wherein:

the second and third position sensors are each coupled to receive the drive force supplied from different motors.

15. The actuator assembly of claim 13, wherein:

the LVDT includes a differential transformer having primary windings and secondary windings, and a movable slug disposed between the primary and secondary windings;

the differential transformer is disposed within the actuation member; and

the movable slug is coupled to, and movable with, the translation member.

16. The actuator assembly of claim 11, further comprising:

a torque summed gear train coupled between each of the motors and the actuation member, the torque summed gear train configured to receive the rotational drive force supplied by each of the motors and transfer the rotational drive force to the actuation member.

17. The actuator assembly of claim 11, wherein:

the ballscrew rotates about an actuator axis;

the ballnut translates along the actuator axis; and

each motor rotates about a motor axis that is parallel to, and displaced from, the actuator axis.

18. An actuation control system, comprising:

a plurality of motors, each motor coupled to receive actuator position control signals and operable, in response thereto, to supply a drive force;

an actuation member coupled to receive the drive force from the motors and configured, upon receipt thereof, to rotate;

a translation member disposed adjacent the actuation member and adapted to couple to an aerospace flight control component, the translation member configured, upon rotation of the actuation member, to translate to a position;

a first position sensor mounted within the actuation member and configured to sense the position of the translation member and supply a first position feedback signal representative of the position thereof;

a second position sensor coupled to receive the drive force from at least one of the plurality of motors and operable, upon receipt thereof, to supply a second position feedback signal representative of the position of the translation member;

a controller adapted to receive control signals and coupled to receive the first and second position feedback signals and configured, in response to the received signals, to supply the actuator position control signals to the plurality of motors.

19. The system of claim 18, wherein the controller is an aircraft flight surface controller.

20. The system of claim 18, wherein the controller is a thrust vector controller.