DESIGN AND CONTROL OF ENGINEERING SYSTEMS UTILIZING COMPONENT-LEVEL DYNAMIC MATHEMATICAL MODEL WITH SINGLE-INPUT SINGLE-OUTPUT ESTIMATOR

• US 20110231021A1
• Filed: 05/29/2009
• Published: 09/22/2011
• Est. Priority Date: 11/03/2008
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Karpman, Boris, Lacour, Mark E., Meisner, Richard P.
• Granted Patent: US 8,195,311 B2
• Time in Patent Office: Days
• US Class Current: 700/282
• 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 error, such that the errors are minimized as a function of single-input, single-output gain matrix.

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 the gain tensor is substantially diagonal, such that off-diagonal elements of the gain tensor have relatively small magnitude as compared to diagonal elements of the gain tensor.

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

6. The control system of claim 1, wherein the control surface is positioned in a working fluid flow in order to control the model state.

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

8. The control system of claim 6, wherein the model input describes a boundary condition for the working fluid flow.

9. The control system of claim 8, wherein the open loop module generates the model output as a further function of a continuity constraint on the model state, and wherein the continuity constraint is based on the boundary condition.

10. The control system of claim 9, wherein the model state describes a spool speed and a cycle time of the processor is 50 ms or less.

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

sensing a boundary state describing the flow at a boundary;

controlling an actuator state as a function of a model feedback, wherein the actuator state describes a control surface positioned in the flow;

generating the model feedback as a function of the boundary state and the actuator state, and as a further function of a physical state related to the flow;

correcting the model feedback for errors based on the boundary state; and

estimating the physical state by minimizing the errors, such that individual errors and states are not cross-correlated.

12. The method of claim 11, wherein the boundary state describes the flow at one of an inlet flow boundary or an outlet flow boundary.

13. The method of claim 12, wherein the actuator state describes a control surface positioned in the flow proximate the inlet flow boundary.

14. The method of claim 12, wherein the actuator state describes a control surface positioned in the flow proximate the outlet flow boundary.

15. The method of claim 11, wherein the physical state describes a rotational state of a rotor positioned in the flow, and wherein the rotational state is constrained by flow continuity between the inlet flow boundary and the outlet flow boundary.

16. The method of claim 15, further comprising minimizing a time rate of change of the rotational state.

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

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

an actuator for changing a control state in order to alter the boundary condition;

a module for generating output as a function of the boundary condition and the control state;

a comparator for generating errors by comparing the output to the boundary condition and the control state;

an estimator 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; and

a controller for directing the actuator as a function of the output, such that the spool speed is controlled.

18. The system of claim 17, wherein the gain matrix is substantially diagonal, such that individual errors are not cross-correlated.

19. The system of claim 17, wherein the boundary condition describes flow related to the spool speed.

20. The system of claim 17, wherein the boundary condition constrains the spool speed based on flow continuity.