Lyapunov-based Steer-by-Wire Control
The automotive Tier 1 supplier for steering systems "thyssenkrupp Presta AG" decided to build a modular research vehicle equipped with a Steer-by-Wire system in order to investigate the requirements and challenges with a missing mechanical connection between steering wheel and steering rack. The position control of the steering rack was controlled by a Lyapunov-based nonlinear controller, developed by the founder of SIGICONTROL, and tested on the prototype vehicle under real conditions.
In order to illustrate the achievable improvements in performance for the same system with a simple changing of control algorithm, a comparison between a conventional state-space controller and the Lyapunov-based nonlinear controller was carried out on a test bench with the following results
Also the road tests with the Lyapunov-based rack control system showed excellent tracking performance as can be seen from a portion of the test data below