A New Control Strategy For Improving Steering Feel Of An EPAS System

Abstract

Terrain conditions of road are a determining factor for the driver's feel of driving. But, power steering is a boon to all the drivers of all classes of vehicles. This paper presents a novel control strategy for an electric power assisted steering system that would help in reducing the undesirable vibration and the driver effort in both the parking and driving state of the vehicle. The performance of steering system depends on the assist torque map. The proposed methods use the assist torque map. Since, a high amount of steering assist gain and nonlinearity of the torque map can have a negative effect in Electric power assisted steering (EPAS) system causing instability; the approach uses a properly designed new law that can circumvent the issues of nonlinearity. Here the modeling of EPAS system has been carried out and model parameters are identified. Based on the available EPAS model, a PID - Sliding Mode controller is designed to control this system. The evaluated performance of designed controllers showed that is successfully improved by the desired controller.