Strain gauge and accelerometer measurement for thrust estimation

Patent metadata

Field	Value
Publication number	US-9829401-B2
Application number	US-201514681300-A
Country	US
Kind code	B2
Filing date	Apr 8, 2015
Priority date	Apr 11, 2014
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

An improved system, apparatus and method for estimating thrust from an engine, and more specifically, a system for estimating thrust from strain gauge and accelerometer measurements. At least one strain gauge is mounted on an engine mount to measure strain to estimate a constant velocity or steady-state portion of thrust. At least one accelerometer is mounted on the vehicle to measure acceleration to estimate a transient portion of thrust. Steady-state thrust estimation and transient thrust estimation are combined to estimate thrust from the engine. An algorithm provides steps for estimating thrust from strain gauge and accelerometer measurements.

First claim

What is claimed is:

1. A system for estimating thrust from an engine, comprising: a vehicle having a propulsion device that is capable of producing thrust, said propulsion device is attached by at least one mounting structure; a plurality of strain gauges mounted on said mounting structure, said strain gauges for producing strain gauge signals indicative of stress; at least one accelerometer mounted on one of said propulsion device or vehicle, said accelerometer producing a signal indicative of acceleration; and at least one processor in communication with said plurality of strain gauges and accelerometer for executing instructions to estimate thrust from strain gauge signals and said acceleration signals, wherein the at least one processor decomposes the strain gauge signals to arrive at a single strain gauge value or a 3-dimensional strain gauge value.

2. The system for estimating thrust as set forth in claim 1 , wherein said instructions estimate a transient portion of thrust by converting accelerometer signals to measured acceleration.

3. The system for estimating thrust as set forth in claim 2 , wherein the transient portion of thrust is estimated by multiplying a mass by measured acceleration.

4. The system for estimating thrust as set forth in claim 1 , wherein said accelerometer is located on said propulsion device.

5. The system for estimating thrust as set forth in claim 1 , wherein said vehicle includes a body and said accelerometer is mounted on the body of the vehicle.

6. The system for estimating thrust as set forth in claim 5 , wherein said body is a fuselage.

7. The system for estimating thrust as set forth in claim 5 , further comprising a second accelerometer located on the propulsion device.

8. A system for estimating thrust from an engine, comprising: a vehicle having an engine capable of producing thrust, said engine attached by at least one mounting member; a plurality of strain gauges mounted on said engine mount, wherein said strain gauges produce signals indicative of stress; at least one accelerometer mounted on said vehicle, said accelerometer producing a signal indicative of acceleration; and at least one processor in communication with said plurality of strain gauges and said accelerometer for estimating thrust from the strain gauge signals and the acceleration signals according to an algorithm, wherein the at least one processor decomposes the strain gauge signals to arrive at a single strain gauge value or a 3-dimensional strain gauge value.

9. The system for estimating thrust as set forth in claim 8 , wherein said algorithm adds steady state measurements and transient measurements to calculate total thrust.

10. The system for estimating thrust as set forth in claim 9 , wherein the algorithm estimates a transient portion of thrust from accelerometer signals.

11. The system for estimating thrust as set forth in claim 10 , wherein the algorithm estimates the transient portion of thrust by multiplying mass by measured acceleration.

12. The system for estimating thrust as set forth in claim 9 , wherein the algorithm estimates a steady state portion of thrust from the strain gauge signals.

13. The system for estimating thrust as set forth in claim 12 , wherein said algorithm estimates the steady state portion of thrust from the strain gauge signals and stiffness of said engine mount.

14. The system for estimating thrust as set forth in claim 12 , wherein said estimate of steady state thrust uses an estimate of drag force on said vehicle.

15. A method for estimating thrust from an engine attached to a vehicle, comprising:
measuring strain, via a plurality of strain gauges, in an engine mount to produce strain gauge signals indicative of stress,
decomposing the strain gauge signals to arrive at a single strain gauge value or a 3-dimensional strain gauge value;
measuring acceleration, via at least one accelerometer, of at least one point of the vehicle to obtain an acceleration measurement;
estimating a constant velocity portion of thrust from the single strain gauge value or the 3-dimensional strain gauge value; and
estimating a transient portion of thrust from the acceleration measurement.

16. The method for estimating thrust from an engine as set forth in claim 15 , further comprising the step of applying an algorithm to the strain measurements and acceleration measurements to estimate thrust.

17. The method for estimating thrust from an engine as set forth in claim 16 , wherein the algorithm adds the constant velocity portion of thrust to the transient portion of thrust to estimate overall thrust.

18. The method for estimating thrust from an engine as set forth in claim 16 , wherein the algorithm estimates the transient portion of thrust from vehicle mass and measured acceleration.

19. The method for estimating thrust from an engine as set forth in claim 16 , wherein the algorithm estimates the constant velocity portion of thrust from strain gauge measurements.

20. The method for estimating thrust from an engine as set forth in claim 16 , wherein the algorithm estimates the constant velocity portion of thrust from strain gauge measurements and stiffness of the engine mount.

Assignees

• Rolls Royce Corp

Inventors

• Mcarthur John

Classifications

• G01L1/22

  using resistance strain gauges · CPC title

• F05D2270/808

  Strain gauges; Load cells · CPC title

• F05D2270/051

  Thrust · CPC title

• G01L5/133 Primary

  for measuring thrust of propulsive devices, e.g. of propellers (aeroplanes B64C; marine propulsion B63H; jet-engines F02K) · CPC title

• F05D2200/13

  Product · CPC title