Predictive controller design for electromagnetic suspension based on mixed logical dynamical model

In this paper, a mathematical model for the developed electromagnetic suspension actuator is established using measured parameters and test data. A main/inner-loop control structure is proposed for its active control where the inner loop undertakes the control of a three-phase motor and applies hysteresis current control method to track the calculated signal by the main loop. With the simplification of the inner-loop control system, an achievable range of control current is acquired. Then, due to the nonlinear damping characteristic of the actuator, a mixed logical dynamical model is built up for the vehicle system and the optimal control to improve vehicle ride comfort is carried out based on the model predictive control method. Simulations are carried out using random uneven road inputs and the results demonstrate that the electromagnetic suspension with the proposed controller can provide better vehicle ride comfort compared with a corresponding passive suspension.