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.

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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

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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

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