Abstract
KEYWORDS – EPS Response, Transient Motion Analysis, Cornering Attitude, Yaw Center, Side Slip Angle
ABSTRACT –
Since its introduction, development of Motor Driven Power Steering (EPS) performance has been mainly focused on characterizing proper steer effort to provide natural steer effort feedback while assisting steer control. Over past years, significant improvement has been achieved in motor assist control and in understanding/controlling hardware friction to provide proper effort build up. But, not much of research has been conducted on how EPS control setting affects steering system response and how it does affect vehicle response especially in lateral dynamics. In this paper, relatively new concept of EPS development strategy is studied and proposed from the standpoint of steering input delivery to road wheel with its effect on steering and lateral dynamic response. As EPS is delivering driver steer input, minimizing the delivery loss in amplitude and in responsiveness is important to develop proper steer performance. In this paper, general concept of EPS system response improvement by controller setting is presented with its effect on steer response and vehicle lateral dynamics. Also, to effectively analyze and correlate improved vehicle response by EPS setting especially in transient motion, new concept of analysis method for transient motion analysis has been studied and proposed.