Optimal Tuning of Cascade Controllers for Feed Drive Systems using Particle Swarm Optimization

Cascade control configurations are one of the widely used control solutions for improving dynamic response of the feed drive systems in the manufacturing industry. However, optimal tuning of cascade controllers in presence of hard nonlinearities such as backlash and friction is still a complex and time-consuming task. This paper presents a computational procedure for tuning P-PI cascade controller by using particle swarm optimization (PSO) for a feed drive system of machine tools in the presence of friction and backlash. The minimizing of the maximum position error during the reversal of the axes is used as an objective function for optimization. The performance of the PSO method is compared in simulations and real-time experiments with the fine tune (FT) method, which is one of the standard methods applied in industry. Both, simulation and real-time experimental studies carried out on a test platform with 8070 Fagor controller show a remarkable improvement in the performance of the cascade control system using the proposed PSO-based strategy.