Robust control for an electric power steering system.

摘要

The EPS (electric power steering) system is one of the safety-critical systems in modern automotive control system. In this thesis, a dynamic model for an EPS system was derived. And then, new controller architecture with an extra logical controller in the steering feedback loop, called motion controller, was proposed to increase the sensitivity of the control system to the system. Finally, a robust control system was designed based on the proposed EPS model and the new controller architecture.; The disturbance signal is the high frequency part of the torque from road to the rack and pinion. The disturbance can be modeled as bounded noise or white noise. Hinfinity technology is often used to attenuate the bounded noise. The control design was divided into two stages. The first stage is to design a PI motor controller to increase the reaction speed. The next stage is to design an Hinfinity motion controller based on the frequency character of the disturbance signal.; Simulations were carried out to demonstrate the controller's performance and robustness characteristics for both bounded noise and white noise. (Abstract shortened by UMI.)