Development of In-Vehicle Evaluation System for Steering Assistance Performance of Electric Power Steering

Due to the advantage of driving convenience from reduced driver's steering effort, electric power steering (EPS) is increasingly employed in vehicle steering systems. However, as the adoption of the EPS device increases, the demand for high performance and quality of EPS has to be assessed. This paper presents the design and implementation of an in-vehicle EPS evaluation system based on steering assistance performance. Our evaluation system consisting of an EPS data acquisition board and evaluation software is installed in the vehicle. The effectiveness of our EPS evaluation system is evaluated and its usefulness is confirmed through 3,061 km of driving in two identical vehicles. The steering linearity error rate of 7.5% or less compared to the reference value measured by the manufacturer is confirmed at three vehicle speeds.