Control of engineering systems utilizing component-level dynamic mathematical model with single-input single-output estimator

• US 8,195,311 B2
• Filed: 05/29/2009
• Issued: 06/05/2012
• Est. Priority Date: 11/03/2008
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Karpman, Boris, Meisner, Richard P., Lacour, Mark E.
• Primary Examiner(s): Kasenge, Charles
• Application Number:
  US12/475,038
• Publication Number:
  US 20110231021A1
• Time in Patent Office: 1,103 Days
• Field of Search: 700/28, 700/29, 700/30, 700/32, 700/33, 700/34, 700/37, 700/44, 700/45, 700/52, 700/54, 700/282, 700/283, 700/287, 60/392.81, 607/72, 607/90, 701/100, 701/101
• US Class Current: 700/45
• CPC Class Codes: G05B 17/02 electric

Abstract

A control system comprises an actuator, a control law and a processor. The actuator positions a control surface and the control law controls the actuator. The processor comprises an open loop module, a corrector, a comparator, and an estimator, and generates model output to direct the control law. The open loop module generates the model output as a function of a model state and a model input. The corrector generates a corrector output as a function of the model output. The comparator generates an error by comparing the corrector output to the model input. The estimator generates the model state as a function of the error, such that the error is minimized as a function of single-input, single-output gain matrix.

Claims

1. A control system comprising:

an actuator for positioning a control surface;

a control law for controlling the actuator, and

a processor for generating model output to direct the control law, the processor comprising;

an open loop module for generating the model output as a function of a model state and a model input;

a corrector for generating a corrector output as a function of the model output;

a comparator for generating errors by comparing the corrector output to the model input; and

an estimator for generating the model state as a function of the errors, such that the errors are minimized as a function of a single-input, single-output gain matrix;

wherein the control surface is positioned in a working fluid flow in order to control the model state;

wherein the model input describes a boundary condition for the working fluid flow;

wherein the open loop module generates the model output as a further function of a continuity constraint on the model state;

wherein the continuity constraint is based on the boundary condition; and

wherein the model state describes a spool speed and a cycle time of the processor is 50 ms or less.

2. The control system of claim 1, wherein the single-input, single-output gain matrix relates each individual model state with an individual error.

3. The control system of claim 2, wherein the gain matrix varies as a nonlinear function of the model input.

4. The control system of claim 2, wherein off-diagonal elements of the gain matrix have smaller magnitude as compared to diagonal elements of the gain matrix.

5. The control system of claim 2, wherein the gain matrix is diagonal, such that off-diagonal elements of the gain matrix are zero.

6. The control system of claim 1, wherein the control surface comprises one of a vane surface or a nozzle surface positioned in the working fluid flow.

7. A method for controlling flow, the method comprising:

positioning a control surface with an actuator;

controlling the actuator with a control law; and

generating model output with a processor to direct the control law, the processor comprising;

an open loop module for generating the model output as a function of a model state and a model input;

a corrector for generating a corrector output as a function of the model output;

a comparator for generating errors by comparing the corrector output to the model input; and

an estimator for generating the model state as a function of the errors, such that the errors are minimized as a function of a single-input, single-output gain matrix;

wherein the control surface is positioned in a working fluid flow in order to control the model state;

wherein the model input describes a boundary condition for the working fluid flow;

wherein the open loop module generates the model output as a further function of a continuity constraint on the model state;

wherein the continuity constraint is based on the boundary condition; and

wherein the model state describes a spool speed and a cycle time of the processor is 50 ms or less.

8. The method of claim 7, wherein the boundary condition describes the flow at one of an inlet flow boundary or an outlet flow boundary.

9. The method of claim 8, wherein the actuator positions the control surface in the flow proximate the inlet flow boundary.

10. The method of claim 8, wherein the actuator positions the control surface in the flow proximate the outlet flow boundary.

11. The method of claim 8, wherein the model state describes a the spool speed of a rotor positioned in the flow, and wherein the spool speed is constrained by flow continuity between the inlet flow boundary and the outlet flow boundary.

12. The method of claim 11, further comprising minimizing a time rate of change of the spool speed.

13. A system for controlling spool speed, the system comprising:

a sensor for sensing a boundary condition that constrains the spool speed;

an actuator for positioning a control surface in order to alter the boundary condition;

a control law for controlling the actuator; and

a processor for generating model output to direct the control law, the processor comprising;

an open-loop module for generating the model output as a function of a model input describing the boundary condition and a model state describing a spool speed;

a corrector for generating a corrector output as a function of the model output;

a comparator for generating errors by comparing the corrector output to the model input describing the boundary condition; and

an estimator for generating the model state as a function of the errors and for estimating the boundary condition as a function of a single-input, single-output gain matrix operating on the errors, such that the errors are minimized as a function of the single-input, single-output gain matrix;

wherein the actuator positions the control surface in a working fluid flow in order to control the model state describing the spool speed;

wherein the model input describes the boundary condition for the working fluid flow;

wherein the open loop module generates the model output as a further function of a continuity constraint on the model state;

wherein the continuity constraint is based on the boundary condition;

wherein the model state describes a spool speed and a cycle time of the processor is 50 ms or less; and

wherein the control law controls the actuator as a function of the output, such that the spool speed is controlled.

14. The system of claim 13, wherein the gain matrix is diagonal, such that individual errors are not cross-correlated.

15. The system of claim 13, wherein the boundary condition describes the working fluid flow as related to the spool speed.

16. The system of claim 13, wherein the boundary condition constrains the spool speed based on flow continuity of the working fluid flow.