Digital twin: model based development of power adjusted steering columns for steer-by-wire

Authors

A. Scholz, M. Mistler - ZF Friedrichshafen AG

Summary

The controlled power adjusted column (cPAC) is a key technology in the context of steer-by-wire and automated driving. While its main functions are comfort adjustment and retraction of the steering wheel in automated driving scenarios, it must fulfill many additional requirements ranging from safety, performance, and comfort, to name a few. The complexity of the cPAC and the large number of interacting requirements demand a development approach that allows for the very early and quick assessment of the interacting mechanical hardware and software designs to avoid costly development loops. In this paper, we present a simulation-driven development approach that is based on building, maintaining, and using multiple digital twins of the real system. The purpose of each twin is to cover a particular area of requirements with a sufficient level of detail so that it can support design decisions without the necessity to use physical hardware. One of the challenges of our approach is to maintain the consistency be-tween twin artefacts that cover the same requirements area but exist in different soft-ware environments. To ensure their consistency, we synchronize the twins whenever new design data is available and perform model-to-model verifications. The validity of this approach is demonstrated by presenting the results of two use cases.