A methodology to evaluate steering performance using Hardware in Loop Testing

In the present generation, steering system plays a major role in vehicle performance and factors like vehicle stability and control. This is because it is a direct interface to the driver. But to tune the steering system to the required standard, it takes several months for an OEM. This increases the lead time and development cost. Steering test benches have been increasingly popular in the recent automobile development process as they offering great advantages. They offer high level of control over system parameters which helps tune the performance of a steering system, especially for the perception of steering feel while driving. There are various steering test benches being developed to solve concerns that OEMs are facing while tuning and validating. A new methodology is defined involving the Steering Test Bench which can perform Hardware in Loop (HIL) and Driver in Loop (DIL) simulations. The objective of this paper is to establish correlation between Vehicle level & Virtual level (DIL) and Mechanical measurement to Component level. While both EPS & HPS steering mechanism can be tested and evaluated in a test rig, here the focus will be on EPS steering system testing in HIL. HIL test benches can perform test on component level and related mechanical tests such as system stiffness, system friction etc. These can be compared with component level data to establish correlation. In addition to this, vehicle level tests like on-center weave, returnability and parking effort tests can also be done and compared with vehicle level. By doing this, it reduces the number of vehicle prototypes and the necessary amount of full vehicle testing which can save development time. There is also additional scope of verifying ADAS features and Haptic feedback. The proposed methods extend the applicability of a steering test bench within the automotive development process by enabling more accurate and reproductible testing performance. In this study, the results has been validated and compared with actual vehicle level scenario and found that it gives a good correlation. In addition to this, there is possibility of establishing correlation for software features like assist and returnability control and soft end stop and reproducing field concerns in the rig level to evaluate improvements made for solving these concerns.