Linear parameter varying control for complex engineering systems.

摘要

Linear Parameter Varying (LPV) control is a powerful gain-scheduling technique for the analysis and control synthesis of nonlinear systems. Among the advantages of the LPV control versus the traditional gain-scheduling approach one can name guaranteed stability and performance over the entire operating regime, systematic design unlike the ad hoc procedure involved in gain-scheduling, computational efficiency and the need for lower computer storage requirements. In the present dissertation, the recent findings in LPV control theory are applied to the real-world applications including control of exhaust after-treatment systems in diesel engines, control of semi-active devices for vibration suppression and, finally, pitch control of wind energy conversion systems with actuator saturation constraints.;The first part of this dissertation addresses the LPV model development and feedforward/feedback control design for a selective catalytic reduction after-treatment system used for reducing NOx emissions from a lean-burn engine. The designed controller is gain-scheduled in real time based on the catalyst operating condition. The principal component analysis is further utilized to overcome the issue of the large number of scheduling parameters involved in the LPV model and to keep the computational complexity reasonable. The proposed design is validated on a commercial high fidelity engine and vehicle simulation and modeling tool.;The second part of the dissertation deals with two different methods of LPV anti-windup control design for a structure base-isolated by a semi-active magneto-rheological damper used to reduce the vibration effects of earthquakes. Single-step and two-step design methods are studied, and the design using the two-step method is experimentally validated on a two-story building model.;In the last part, an LPV anti-windup control design for pitching the blades of a wind turbine while it operates above the rated wind speed is proposed. Both magnitude and rate saturation constraints on the pitch actuators are accommodated using a new formulation in LPV framework. The actuator limitations can cause performance degradation or even instability for instance in case of extreme gusts. The proposed control design method is finally validated on a high fidelity aero-elastic wind turbine model.