A Control Strategy for Kickback Reduction using Electric Power Steering and Combined Chassis Control 2007-01-3658

Good road feel means that the driver can interpret road conditions through the steering wheel. This is one of the most important requirements demanded by car makers. However, over-sensitivity in steering transmission could cause inconvenience to the driver especially maneuvering on rough roads and hence must be isolated by the steering system or by other means. To overcome this, firstly we have to distinguish diverse road conditions and apply appropriate control strategy.

In this paper we've proposed two control strategies to enhance steering performance on rough roads. The first method analyzes motor position signal of Electric Power Steering (or EPS) where the road roughness is separated from the motor position signal through signal processing. The roughness then is compensated for by using EPS to obtain a better steering feel. The second method utilizes CAN transferred vehicle information from Continuous Damping Control system (or CDC). CDC sets damping force according to driving condition and road roughness. The roughness of the road can be detected using vertical acceleration sensors positioned on either front wheel. The shift control algorithm method performs better especially on rough road. These two methods were compared on rough road conditions with conventional steering system to show the enhanced steering performance.