Pulse-width-modulated feedback control of nonlinear systems: optimal linearization-based digital redesign approach

Abstract

This paper presents an efficient design methodology for pulse-width-modulated (PWM) feedback control of a nonlinear system. To avoid the non-causality between the PWM controller and the widely used modulation law – the principle of equivalent area, the analogue controller to be modulated is first digitally redesigned based on the optimal linear model of the nonlinear system, and is then PWM redesigned, which is an extension of our previous result. It is shown that the proposed technique achieves a uniformly semi-globally practically asymptotic stability of the actual nonlinear PWM feedback control system. An example is provided to illustrate the effectiveness of the proposed methodology.

Keywords:

• pulse-width-modulated (PWM) control
• nonlinear system
• digital redesign
• optimal linearization
• uniform semi-global practical asymptotic stability

Acknowledgements

This research was supported by Basic Science Research Programme through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2010-0003766).