Survey Constructive nonlinear control: a historical perspective

Position regulation of a magnetic levitation device is achieved through a control Lyapunov function (CLF) feedback design. It is shown experimentally that by selecting the CLF based on the solution to an algebraic Riccati equation it is possible to tune the performance of the controller using intuition from classical LQR control. The CLF is used with Sontag's universal stabilizing feedback to provide enhanced transient performance farther away from the origin than was achieved with the LQR controller.

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Nonlinear control for magnetic levitation of automotive engine vales

Variable structure surge control for constant speed centrifugal compressors

This paper describes the design of and experiments with a nonlinear feedback controller implemented on an industrial type axial compressor. Two-dimensional (2-D) actuation with a ring of bleed valves was used to prevent surge and stall instabilities. For the interstage location of the bleed valves the nonlinear controller design was based on a modified version of the Moore-Greitzer model, also presented in the paper. For downstream bleed, the experimentally determined stability region closely matched the largest region possible under the constraints of the actuators.

Nonlinear control experiments on an axial flow compressor

An improvement in control performance of piston-actuated active surge control for centrifugal compressor by using integral action is presented in this paper. The active surge control is designed by using linear quadratic requlator (LQR) method based on the linearized system around the operating point. Simulation results show the active controller is able to stabilize the surge but not able to reach the desired operating point. The reason for this is the piston drift during surge stabilization. The surge control system is then enhanced by including integral action for counter acting the drift. Simulation results show the enhanced system is performing well in stabilizing surge without piston drift and reaching the desired operating point, but the piston position has non zero stationary value. One more integral is applied to the system to bring the piston position back to the origin. Applying double integrals action also results less required piston stroke for the surge stabilization.

Piston-actuated active surge control of centrifugal compressor including integral action

We compare linear and nonlinear controllers for an axial flow compressor. The control laws are designed for asymmetric interstage bleed valve actuation. We show that a nonlinear L/sub g/V controller achieves a larger region of attraction than that achieved by an LQR controller.

Linear vs. nonlinear control of an axial flow compressor

A nonlinear control law is designed for a low order model of an axial flow compressor with a ring of bleed valves after the last compressor stage. The controller is implemented on a low speed, three stage experimental compressor. The region of attraction guaranteed by the control law is experimentally determined and is larger than that of the uncontrolled compressor.

D. Fontaine

Papers

Nonlinear control experiments on an axial flow compressor

Linear vs. nonlinear control of an axial flow compressor

Nonlinear control experiments on an axial flow compressor