Parameter Optimisation of EPAS Using CAE

Abstract: To keep up with technological as well as logistical challenges of the modern automobile market, major car manufacturing firms have resorted to virtual simulation tools. This enables the development as well as validation of vehicular models much before resources are invested into a new physical prototype.This project focuses on the development of a tool that would help in optimising the handling parameters of a vehicle. This is achieved by creating an optimization routine for tuning the various parameters of the Electronic Power Steering (EPAS). This process is usually done manually, by on-track testing, due to the difficulties in correlating Subjective Assessments (SA) with Objective Metrics (OM). Automating this process would help to reduce the overall research and development time, by providing a baseline tune for the EPAS parameters which could then be finely tweaked by manual track testing.The tool is built by interfacing various software in a multi-objective optimisation environment known as ModeFrontier. The modelling and simulations are performed in IPG CarMaker, with the post processing of the results taken care of by Sympathy for Data. Multiple optimization algorithms were tested to achieve the best optimisation routine. The EPAS parameters, namely the Basic Steering Torque, Active Return and Active Damping, act as the input to the optimization routine. The outputs of the model are the Objective Metrics, which provide a clear indication of the dynamic performance of a component. These metrics are optimized to _t the Steering DNA structure, which uniquely describes the attributes of a vehicle. The final optimised vehicle is manually tested at the track, to determine the real driving feel.