Strategy for Analysis and Design of a Digital Robust Controller for Nonlinear Control Systems

Abstract

This paper proposes a strategy for the analysis and design of a nonlinear robust control system with variable parameters. A digital robust controller is implemented in the system. The approach for the controller design is founded on introduction of system compensation with two degrees of freedom. As a result, the targeted robustness of the system is achieved. The system’s stability and robust assessment is based on the interaction between its nonlinear and linear sections. D-partitioning, timeresponse and describing function analyses are implemented before and after the robust compensation. These analyses demonstrate significant improvement of the system performance in terms of insensitivity to variations of the system parameters. The digital robust controller is build of microcontrollers, based on the difference equations of its sections.