Development of Robust Active Rear Streering Control for Automobile

A new robust control logic for the active rear steering (ARS) system of an automobile is presented. It maintains good control performance even if the vehicle parameters and/or road condition are changed. This system makes the vehicle follow the desired dynamic model by the state feedback of both yaw rate and side silp angle. To utilize noisy yaw rate sensor and also to maintain high robust control performance, a controller with frequency-dependent gain characteristics was designed by μ synthesis. To estimate the side silp angle using a noisy sensor, a time-variant observer applying a frequency filter is introduced. Results of simulations and actual tests prove the great effect of this new ARS control.