GA Optimized PI-PDN Robust Control of a 1-DOF Maglev Precision Position System

This paper investigates 2 difficult problems encountered in magnetic levitation systems: robust control design and disturbance rejection. A PI-PDN robust control strategy is developed to control the position of a 1-degree-of-freedom (DOF) magnetic levitated rigid beam system or MLS for precision positioning applications under parametric variations, uncertainties, and external disturbances. The proposed PI-PDN gains are optimized by employing a Genetic Algorithm (GA), Marine Predator Algorithm (MPA), and Particle Swarm Optimization (PSO). GA-tuned gains lead to manifold improvement in key time and frequency domain performance specifications of rise time, settling time, overshoot, tracking error, bandwidth, classical gain, and phase margins. Additionally, the metrics of disk margins (DM) are employed for assessing the robustness of a closed-loop system subjected to simultaneous variation in gain and phase. To demonstrate the performance and effectiveness of the proposed GA-PI-PDN topology, numerical simulation results are compared with corresponding results of the benchmark PIDN with that of PI-PDN and GA-PI-PDN. The developed control algorithms were deployed on a dedicated embedded system utilizing Simulink automatic C++ code generation capabilities. The development of different control strategies was aided by building high fidelity mathematical model of electromagnets and experimental determination of important model parameters.