Title: Robust controller design for an electromagnetic active suspension subjected to mixed uncertainties

Authors: Yongchao Zhang; Jianyong Cao; Guoguang Zhang; Fan Yu

Addresses: Institute of Automotive Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240, China; School of Mechanical Engineering, Taizhou University, 1139 Shifu Road, Jiaojiang District, Taizhou, Zhejiang Province 318000, China ' Institute of Automotive Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240, China ' Institute of Automotive Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240, China ' Institute of Automotive Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240, China

Abstract: This article focuses on the modelling and robust control of a DC motor-based electromagnetic active suspension. Due to the small damping of the motor, the moments of inertia of the rotor and the nut can significantly affect the high-frequency performance of the suspension system and so, they are taken into consideration in the system modelling. In addition, parameter variations of the vehicle system and the unmodelled high-order dynamics of the actuator could influence the control effectiveness. Thus, the mixed uncertainties, composed of both multiple parameter uncertainties and the unmodelled high-order dynamics of the suspension and actuator are taken into account in the system model. To ensure the robustness and performance of the uncertain suspension system, a robust controller based on mixed μ-synthesis is designed. An easy method of choosing the weighting functions is proposed. The simulation results show the mixed μ-synthesis controller can meet the requirement of robust performance in the presence of mixed uncertainties and can achieve good ride comfort.

Keywords: electromagnetic active suspension; DC motors; uncertainty; μ-synthesis; robust control; controller design; vehicle design; vehicle suspension; modelling; moments of inertia; parameter uncertainties; unmodelled dynamics; actuators; ride comfort.

DOI: 10.1504/IJVD.2013.057495

International Journal of Vehicle Design, 2013 Vol.63 No.4, pp.423 - 449

Received: 16 Sep 2011
Accepted: 16 Oct 2012
Published online: 16 Oct 2014 *

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