ELECTROMECHANICAL ACTUATOR STRAIN GAUGE TEMPERATURE COMPENSATION DEVICE

• US 20150127233A1
• Filed: 11/07/2013
• Published: 05/07/2015
• Est. Priority Date: 11/07/2013
• Status: Active Grant

• Current Assignee: Goodrich Corporation (Rtx Corporation)
• Original Assignee: Goodrich Corporation (Rtx Corporation)
• Inventors: Drennen, David, Keller, Steven
• Granted Patent: US 9,221,440 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60T 8/1703 for aircrafts
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: F16D 2066/001 Temperature
• CPC Class Codes: F16D 2066/005 Force, torque, stress or strain
• CPC Class Codes: F16D 65/18 adapted for drawing members together , e.g. for disc brakes
• CPC Class Codes: F16D 66/00 Arrangements for monitoring working conditions, e.g. wear, temperature
• CPC Class Codes: G01L 1/2281 for temperature variations
• CPC Class Codes: G01L 5/0061 Force sensors associated with industrial machines or actuators for the specific machine or actuator involved see relevant class, e.g. F01, F04, F16, B66, E21

Abstract

The EMA may comprise an EMA housing, a strain gauge coupled to the EMA housing, the strain gauge comprising a Wheatstone bridge, the Wheatstone bridge comprising a first group of resistors coupled in parallel with a second group of resistors, a controller coupled to the strain gauge, a variable resistance resistor coupled to the Wheatstone bridge, the variable resistance resistor configured to derive a temperature of the EMA housing based upon a temperature of the variable resistance resistor and configured to provide feedback to the controller, the controller adjusting a force applied by the EMA based upon the temperature of the EMA housing.

Claims

1. An electromechanical actuator (EMA) comprising:

an EMA housing;

a strain gauge coupled to the EMA housing, the strain gauge comprising a Wheatstone bridge,

the Wheatstone bridge comprising a first group of resistors coupled in parallel with a second group of resistors;

a controller coupled to the strain gauge;

a variable resistance resistor coupled to the Wheatstone bridge, the variable resistance resistor configured to derive a temperature of the EMA housing based upon a temperature of the variable resistance resistor and configured to provide feedback to the controller,

the controller adjusting a force applied by the EMA based upon the temperature of the EMA housing.

2. The EMA of claim 1, wherein the controller is configured to measure a resistance of the variable resistance resistor to obtain a temperature of the EMA housing.

3. The EMA of claim 2, wherein the variable resistance resistor is coupled in series with the Wheatstone bridge.

4. The EMA of claim 1, wherein one resistor of the first group of resistors or the second group of the resistors in the Wheatstone bridge is strain sensitive, the resistance of the one resistor thereof varying with the load measured by the Wheatstone bridge.

5. The EMA of claim 1, wherein each resistor of the first group of resistors or the second group of the resistors in the Wheatstone bridge comprises a known resistance.

6. The EMA of claim 1, wherein the controller tabulates a plurality of loads based upon a plurality of temperatures measured by the variable resistance resistor.

7. The EMA of claim 6, wherein the controller tabulates a plurality of resistances based upon the plurality of temperatures measured by the variable resistance resistor.

8. The EMA of claim 7, wherein the controller adjusts the force applied by the EMA based upon each of a tabulated plurality of resistances.

9. An electromechanical actuator (EMA) comprising:

a strain gauge comprising a circuit for measuring a strain on an EMA housing; and

a controller coupled to the strain gauge, wherein the controller adjusts a force applied by the EMA based upon a resistance of a variable resistance resistor coupled in series to the circuit for measuring a strain on an EMA housing.

10. The EMA of claim 9, wherein the circuit for measuring a strain on an EMA housing comprises a first group of resistors coupled in parallel with a second group of resistors.

11. The EMA of claim 9, wherein the controller determines a temperature of the EMA based upon the resistance of the variable resistance resistor.

12. The EMA of claim 9, wherein the controller adjusts a force applied by the EMA based upon the resistance of the variable resistance resistor.

13. The EMA of claim 9, wherein the circuit for measuring a strain on an EMA housing is a Wheatstone bridge.

14. The EMA of claim 9, wherein the resistance of the variable resistance resistor is affected by a temperature of the variable resistance resistor.

15. The EMA of claim 13, wherein each resistor of a first group of resistors and a second group of resistors in the Wheatstone bridge comprises a known resistance.