A New Slip Algorithm for Use in Hardware-in-the-Loop Simulation to Evaluate Anti Slip Control of Vehicles

Abstract

Hardware in the Loop (HIL) systems is widely used for testing vehicle controllers in automotive industry. But algorithms for simulation of the vehicle dynamics have to consider the special restrictions for HIL that is a fixed simulation time constant. Due to limitations of computing power the step size often is set to 1ms. Especially for calculation of the wheel slip this will cause a problem when speed starts from zero. Thats why a lot of authors propose a small vehicle speed at the beginning of the simulation. For evaluation of anti slip controllers in HIL systems this is not possible because stand still is the general starting point for the anti slip controller. Different ideas exist in literature to solve this problem but none of them consider the HIL restriction in an overall approach. In this paper a new algorithm for slip calculation is presented. Therefore two different approaches will be analyzed and combined to a new algorithm. Simulation results show the feasibility for HIL systems.