Static Antiwindup Design for Nonlinear Parameter Varying Systems With Application to DC Motor Speed Control Under Nonlinearities and Load Variations

In this brief, a novel scheme to design an antiwindup gain by ensuring local stability for nonlinear parameter varying systems having an input saturation is derived. Antiwindup compensator (AWC) design is provided for a dynamic output feedback controller that meets the desired closed-loop stability and performance specifications in the absence of the input saturation. A linear matrix inequality-based condition by application of Lyapunov theory, a local sector condition, an upper bound on the nonlinearity, and parametric bounds is formulated for the AWC design to ensure asymptotic and L-2 stability. In contrast to the conventional approaches for nonlinear systems, the proposed AWC approach accounts for parametric variations, considers computationally simple static antiwindup, is straightforward for implementation, is useful for the existing control system, and can reduce the design conservatism. The proposed AWC design approach is tested for a practical scenario on the dc servo system control under armature nonlinearity, load variations, and control input saturation. Both simulation and experimental results are provided.