The assist performance of electric power steering system is related to the safety of steering operation, and the system's stability, tracking and reject disturbance are the main factors that affect steering assist performance. The object studied in this paper is to enhance the tracking performance of electric power steering system and resist the influence of road disturbance and torque sensor noise. Firstly, the defaults of typical control theory and modern theory were analyzed. Secondly, H-infinity) control theory was introduced and applied to the designing of electric steering system, LMI method was used in the designing. Thirdly, the step responses of assist torque error on steering wheel input, torque sensor noise and road disturbance were simulated on computer, the simulation results proved that electric power steering control system designed has a good tracking performance, and can resist the influence of road disturbance and torque sensor noise. The results give a basis for the design of electric power steering system. Main factors affected on electric steering system's assist performance were analysed in this paper, and H-infinity control theory was applied to research on assist performance of assist steering system, furthermore a controller based on LMI method was designed. Some conclusions can be drawn from this paper: 1) In order to guarantee the steering drive's security, the electric steering must have good assist performance. While stability, tracking performance and reject disturbance are the main performance indexes to determine weather the system has good assist steering performance or not. 2) The transfer function H-infinity norms between steering wheel input torque, torque sensor noise, road disturbance and assist torque error were looked as the designing performance indexes of optimal H-infinity controller, LMI method is a valid way to design optimal H-infinity controller. 3) Simulations on computer proved that the electric steering close loop control system has good assist performance with optimal H-infinity controller. The research results provide foundations for the further designing of electric steering system. 4) Optimal H-infinity controller design method can apply to electric steering control system of all kinds of automobiles.
Study on assist performance of vehicle electric power steering system
Untersuchung der Leistung von elektrischen Fahrzeuglenkungs-Assistenzsystemen
2004
6 Seiten, 5 Bilder, 6 Quellen
Conference paper
English
Electric power assist steering
Online Contents | 1996
Electric power assist steering
Tema Archive | 1996
|