Increasing Electronic Stability Controller Application Efficiency Using CAE 2015-01-0021
Computer aided engineering (CAE) methods have been part of Electronic Stability Control (ESC) system development since its introduction to the market in 1995, especially in the testing and verification phase. Over time, additional CAE tools and methods have been introduced, ranging from small self-learning algorithms to automatic tuning tools for individual functions. Since the end of 2009, ECE regulations have allowed the use of CAE methods for ESC homologation, and in North America, the exemption from FMVSS126 compliance for aftermarket parts was phased out in 2012. Following these legislative changes, several original equipment manufacturers, aftermarket companies and ESC suppliers are using vehicle dynamics computer simulation methods to predict ESC performance and homologate vehicles. The emphasis of such work has been on either managing the increasing complexity of vehicle programs with a large number of buildable combinations, or to demonstrate compliance after vehicle parts have been modified. However, actual ESC application and performance calibration work has usually been conducted on a real prototype vehicle. This in-vehicle work typically starts from a set of initial calibration parameters based on either a segment-specific estimation, or a parameter set from a predecessor vehicle line. The work presented in this paper proposes a structured way to conduct model correlation and subsequent initial yaw stability controller base application and initial calibration in CAE, prior to prototype vehicle access. Using the commercially available vehicle dynamics simulation software Tesis veDYNA in combination with Matlab/Simulink, proprietary tools and scripts have been written for both simulation correlation and application work. Basic application steps for high-μ road conditions have been transferred into CAE. These include identifying vehicle characteristics such as steering ratio and characteristic velocity, together with setting up the brake hydraulic model. Vehicle manoeuvres with many different variations have been modelled in the simulation environment to assist the application engineer in initial calibration of the ESC system to meet internal, customer and legislative requirements. Results indicate that it is feasible to conduct base application and refine ESC performance in CAE before a prototype vehicle is accessible.