µ control of vehicle active suspension and electric power steering system

The integrated control model of active suspension and electrical power steering system was established. General uncertainties which can cause vehicle unstable were considered. An integrated controller for both active suspension and electric power steering system of vehicle was constructed based on μ control theory. The μ control law minimized an objective function (H2 norm) for a given controller structure, accounting for requirements of steering torque amplification, steering response, steering feel and the performances of vehicle. The calculated structured singular value and simulation results showed that the steering feel, dynamics performances of vehicle and the control system's robustness were all distinctly improved.