A simple approach to electromagnetic actuator control based on asymptotically exact linearization

Abstract

This paper deals with system identification and robust control of a nonlinear electromagnetic actuator and proposes a simple, robust, and easy-to-implement compensation law for linearization, known as asymptotically exact linearization. There are many practical applications where this type of electromagnetic actuator is used: electromagnetic valve actuators of combustion engines, artificial heart actuators, electromagnetic brakes, etc. The investigated system is open-loop unstable and nonlinear and has a restricted equilibrium region. System identification experiments are presented with an emphasis on the design procedure of an H ∞ controller. The experimental results demonstrate that the controller design problem can be successfully handled within the framework of robust control. This paper reflects a rather pragmatic control approach and, although it does not introduce novel control strategies, might be valuable reading for practicing engineers.