Abstract
Aiming to realize levitation for a novel permanent magnetic levitation system, this paper proposes a double control strategy. The coupled dynamic model with two subsystems was established at first. According to the analysis of stable levitation, four joint control strategies of air gap length and rotation angle were designed. Then, the controller parameters tuning was implemented utilizing the improved PSO (particle swarm optimization) algorithm with non-linear inertia weight. At last, step response simulations and experiments were carried out to compare the performance of the proposed four control strategies. Results demonstrate the validity of PSO using for tuning proportional-integral-derivative (PID) parameters. In addition, the parallel double PD controller and cascade double PD controller both have better dynamic performance but more significant steady-state error. When using PID control for the air gap, the error could be eliminated. Compared with the parallel PID-PD control strategy, the cascade control is competitive in terms of 0.03 s rising time, 4.3 s settling time, and 24% peak overshoot.