2011 Volume 5 Issue 5 Pages 789-804
In this paper, to realize the comfortable steering feeling during driver's steering or a rough road running, we design a control system of an electric power steering (EPS) for a vehicle with an active stabilizer. Although control systems of the conventional EPS are designed generally to obtain the comfortable steering feeling similar to that using a hydraulic power steering (HPS), the steering feeling might not be realized on a rough road. We propose a design strategy for the control system of the EPS in consideration of the active stabilizer to avoid side effects to the steering system by the reaction force of the front tire due to roll stiffness control for the active stabilizer. According to the design strategy, a controller of the EPS is designed and tuned to realize the HPS-like steering feeling by applying a gain-scheduled control corresponding to both a vehicle speed and a sensor torque on a steering axis in consideration of the active stabilizer, which is designed so as to not only reduce the roll motion of a vehicle body but also suppress the restoring torque which acts on the steering axis through the front tire during the rough road running. It is verified that the control system of the EPS designed is effective to realize the HPS-like steering feeling during the driver's steering and suppress the rotational vibration of a steering wheel during the rough road running.
