Optimization design of semi-active controller for in-wheel motors suspension

Owing to significant influences of in-wheel motors on the performance of suspension, a modified GPSO-LQG controller is proposed for one-quarter vehicle suspension with the purpose of optimizing suspension performance for entire speed ranges. After the introduction of one-quarter vehicle suspension model, road surface excitation model and magneto-rheological damper model, the GPSO-LQG controller is investigated with three weighted coefficients optimized by utilizing the Genetic Particle Swarm Optimization (GPSO). With the intension of meeting the requirements across the speed range, the weighted coefficients are presented as functions of speed in a modified GPSO-LQG controller while constraint values (alpha,beta) are given in the optimization of the weighted coefficients. Subsequently, simulation models are constructed with two working conditions. In the end, simulation results indicate that the modified GPSO-LQG controller reduces body acceleration by 8.37 % at a low speed and decreases the tire dynamic load by 8.55 % at a high speed, as compared with a GPSO-LQG controller. In terms of its outstanding advantages in improving the performance of suspension, the modified GPSO-LQG controller is more suitable for in-wheel motors suspension.