Design Method of Driving Force and Electric Power Steering Control to Improve Vehicle Lateral Motion Characteristics

In this paper, we propose new controls and their design methods of driving force and Electric Power Steering (EPS). These controls enable to improve a vehicle lateral motion characteristics. First, Kinetic equations including characteristics of EPS system, vehicle lateral and longitudinal motions are clarified. Control-design policies are derived from their frequency responses. Then, we find that compensations of external disturbances and characteristics valiations are important, so driving force controller which compensates longiudinal and vertical disturbances at wheels and EPS controller which compensates vehicle lateral motion valiations and lateral disturbances at wheels are designed based on H-infinity control theory. Finally, their effectivenesses are shown by simulations and vehicle experimentations.