Compact aero-thermo model stabilization with compressible flow function transform

Patent metadata

Field	Value
Publication number	US-2016003164-A1
Application number	US-201414769860-A
Country	US
Kind code	A1
Filing date	Mar 14, 2014
Priority date	Mar 15, 2013
Publication date	Jan 7, 2016
Grant date	—

Abstract

Systems and methods for controlling a fluid based engineering system are disclosed. The systems and methods may include a model processor for generating a model output, the model processor including a set state module for setting dynamic states of the model processor, the dynamic states input to an open loop model based on the model operating mode, wherein the open loop model generates a current state model as a function of the dynamic states and the model input, wherein a constraint on the current state model is based a series of cycle synthesis modules, each member of the series of cycle synthesis modules modeling a component of a cycle of the control system and including a series of utilities, the utilities are based on mathematical abstractions of physical properties associated with the component. The series of cycle synthesis modules may include a flow module for mapping a flow curve relating a compressible flow function to a pressure ratio and for defining a solution point located on the flow curve and a base point located off the flow curve.

First claim

What is claimed is:

1 . A control system ( 100 ), comprising:
an actuator ( 124 ) for positioning a control device ( 130 ), the control device defining a flow path through an aperture, the aperture defining a pressure drop along the flow path, and comprising a control surface, wherein the actuator ( 124 ) positions the control surface in order to regulate fluid flow across the pressure drop based on a model state; a control law ( 111 ) for directing the actuator ( 124 ) as a function of a model output; and a model processor ( 110 ) for generating the model output, the model processor comprising:
an input object ( 220 ) for processing model input and setting a model operating mode;
a set state module ( 420 ) for setting dynamic states of the model processor ( 110 ), the dynamic states input to an open loop model ( 410 ) based on the model operating mode;
wherein the open loop model ( 410 ) generates a current state model as a function of the dynamic states and the model input, wherein a constraint on the current state model is based on a series of cycle synthesis modules, each member of the series of cycle synthesis modules modeling a component of a cycle of the control device ( 130 ) and comprising a series of utilities, the utilities based on mathematical abstractions of physical properties associated with the component, the series of cycle synthesis modules including a flow module for mapping a flow curve relating a compressible flow function to a pressure ratio and for defining a solution point located on the flow curve and a base point located off the flow curve;
an estimate state module ( 440 ) for determining an estimated state of the model based on a prior state model output and the current state model of the open loop model; and
an output object ( 240 ) for processing the estimated state of the model to determine the model output.

2 . The control system ( 100 ) of claim 1 , wherein the estimate state module ( 440 ) generates error as a function of a slope defined between the base point and the solution point.

3 . The control system ( 100 ) of claim 2 , wherein the estimate state module ( 440 ) estimates the slope by moving the solution point along the flow curve, such that the error is minimized.

4 . The control system ( 100 ) of claim 3 , wherein the control law directs the actuator to position the control surface based on a feedback that is a function of the slope, such that the compressible flow function defines the fluid flow and the pressure ratio defines the pressure drop.

5 . The control system ( 100 ) of claim 4 , wherein the control law directs the actuator to position the control element under a condition of low fluid flow, such that a slope of the flow curve approaches zero at the operating point.

6 . The control system ( 100 ) of claim 4 , wherein the control law directs the actuator to position the control element under a condition of choked fluid flow, such that an inverse slope of the flow curve approaches zero at the operating point.

7 . The control system ( 100 ) of claim 1 , wherein the model input includes at least one of raw effector data, boundary conditions, engine sensing data, unit conversion information, range limiting information, rate limiting information, dynamic compensation determinations, and synthesized lacking inputs.

8 . The control system ( 100 ) of claim 1 , wherein the control device ( 130 ) is a gas turbine engine.

9 . The control system of claim 8 , wherein the aperture comprises a variable-area nozzle.

10 . A method for controlling a control device ( 130 ), the control device defining a flow path through an aperture, the aperture defining a pressure drop along the flow path, the method comprising:
generating a model output using a model processor ( 110 ), the model processor ( 110 ) comprising:
an input object ( 220 ) for processing model input and setting a model operating mode;
a set state module ( 420 ) for setting dynamic states of the model processor, the dynamic states input to an open loop model ( 410 ) based on the model operating mode;
wherein the open loop model ( 410 ) generates a current state model as a function of the dynamic states and the model input, wherein a constraint on the current state model is based on a series of cycle synthesis modules, each member of the series of cycle synthesis modules modeling a component of a cycle of the control device and comprising a series of utilities, the utilities based on mathematical abstractions of physical properties associated with the component, the series of cycle synthesis modules including a flow module for mapping a flow curve relating a compressible flow function to a pressure ratio and for defining a solution point located on the flow curve and a base point located off the flow curve;
an estimate state module ( 440 ) for determining an estimated state of the model based on a prior state model output and the current state model of the open loop model ( 410 ); and
an output object ( 240 ) for processing the estimated state of the model to determine a model output;
directing an actuator ( 124 ) associated with the control device ( 130 ) as a function of the model output using a control law; and positioning the control device ( 130 ) comprising a control surface using the actuator ( 124 ), wherein the actuator ( 124 ) positions the control surface in order to control the model state to regulate fluid flow across the pressure drop based on the model state.

11 . The method of claim 10 , wherein the estimate state module ( 440 ) generates error as a function of a slope defined between the base point and the solution point.

12 . The method of claim 11 , wherein the estimate state module ( 440 ) estimates the slope by moving the solution point along the flow curve, such that the error is minimized.

13 . The method of claim 12 , wherein the control law directs the actuator to position the control surface based on a feedback that is a function of the slope, such that the compressible flow function defines the fluid flow and the pressure ratio defines the pressure drop.

14 . The method of claim 13 , wherein the control law directs the actuator to position the control element under a condition of low fluid flow, such that a slope of the flow curve approaches zero at the operating point.

15 . The method of claim 14 , wherein the control law directs the actuator to position the control element under a condition of choked fluid flow, such that an inverse slope of the flow curve approaches zero at the operating point.

16 . A gas turbine engine ( 130 ) comprising:
a fan; a compressor section downstream of the fan; a combustor section downstream of the compressor section; a turbine section downstream of the combustor section; an actuator ( 124 ) for positioning the gas turbine engine ( 130 ), wherein the actuator ( 124 ) positions a control surface of an element of the gas turbine engine, the element of the gas turbine engine defining a flow path through an aperture, the aperture defining a pressure drop along the flow path to control a model state and to regulate fluid flow across the pressure drop based on the model state; a control law ( 111 ) for directing the actuator ( 124 ) as a function of a model output; a model processor ( 110 ) for generating the model output, the model processor comprising:
an input object ( 220 ) for processing model input and setting a model operating mode;
a set state module ( 420 ) for setting dynamic states of the model processor, the dynamic states input to an open loop model ( 410 ) based on the model operating mode

Assignees

• United Technologies Corp

Inventors

• Karpman Boris
• Shishkin Serge L

Classifications

• G05B23/0254

  based on a quantitative model, e.g. mathematical relationships between inputs and outputs; functions: observer, Kalman filter, residual calculation, Neural Networks · CPC title

• F04D29/321

  for axial flow compressors · CPC title

• F02C9/16 Primary

  Control of working fluid flow (F02C9/48 takes precedence; control of air-intake flow F02C7/057) · CPC title

• F02C9/20

  by throttling; by adjusting vanes · CPC title

• F05D2260/85

  Starting · CPC title