METHOD OF POSITIONING A CONTROL SURFACE TO REDUCE HYSTERESIS

• US 20130142620A1
• Filed: 11/01/2012
• Published: 06/06/2013
• Est. Priority Date: 12/01/2011
• Status: Active Grant

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: MOORE, Jonathan Michael, HAYDN-SMITH, Simon Kenneth
• Granted Patent: US 9,176,488 B2
• Time in Patent Office: Days
• US Class Current: 415/13
• CPC Class Codes: F01D 17/085 to temperature
• CPC Class Codes: F01D 17/162 for axial flow, i.e. the vanes turning around axes which are essentially perpendicular to the rotor centre line F01D17/167 takes precedence
• CPC Class Codes: F01D 17/24 electrical
• CPC Class Codes: F02C 9/20 by throttling; by adjusting vanes
• CPC Class Codes: F04D 27/001 Testing thereof; Determination or simulation of flow characteristics; Stall or surge detection, e.g. condition monitoring
• CPC Class Codes: F05D 2270/80 Devices generating input signals, e.g. transducers, sensors, cameras or strain gauges
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G05B 2219/41208 Lookup table for load, motor torque as function of actual position error

Abstract

A method of determining the actual position of a control surface (27). The method comprises receiving a signal (34) representative of a required position of the control surface (27), repositioning the control surface (27) in response to the signal (34) by moving an actuator (26), measuring a secondary position indicator, calculating the actual position of the control surface (27) on the basis of the secondary position indicator and, comparing the actual position with the required position.

Claims

1. A method of determining the actual position of a control surface, the method comprising:

receiving a signal representative of a required position of the control surface;

repositioning the control surface in response to the signal by moving an actuator;

measuring a secondary position indicator;

calculating the actual position of the control surface on the basis of the secondary position indicator and comparing the actual position with the required position.

2. A method according to claim 1, wherein the secondary position indicator comprises a force measurement.

3. A method according to claim 2, wherein the actuator comprises a motor for repositioning the control surface, and the force measurement comprises a measurement of the load imposed on the motor.

4. A method according to claim 1, wherein the secondary position indicator comprises a temperature measurement.

5. A method according to claim 4, wherein the actuation system comprises a lubricated bearing configured to enable repositioning, and the temperature measurement comprises a measurement of the temperature of at least one of the bearing and the bearing lubricant.

6. A method according to any claim 1, wherein the step of calculating the actual position comprises comparing the secondary position indicator measurement with the corresponding actual position in a look up table or graph.

7. A method according to claim 1, wherein the step of calculating the actual position comprises calculating the actual position as a function of the secondary position indicator measurement.

8. A method according to claim 1, wherein the method further comprises further repositioning the actuator subsequent to the comparison of the actual and required positions, such that the control surface is positioned closer to the required position.

9. A system for determining the actual position of a control surface, configured to carry out the steps of claim 1.

10. A compressor for a gas turbine engine comprising a system according to claim 9.

11. A gas turbine engine comprising a compressor according to claim 10.