Title: Load-dependent observer design for active suspension systems

Authors: Hui Zhang; Junmin Wang; Nong Zhang

Addresses: Merchant Marine College, Shanghai Maritime University, Shanghai 201306, China ' Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210, USA ' Faculty of Engineering, Mechatronics and Intelligent Systems, University of Technology, Sydney, P.O. Box 123, Broadway, NSW 2007, Australia

Abstract: In the paper, a quarter-car model with an active suspension system is first considered. To incorporate the variation of sprung mass, a polytopic model with two vertices is established. In the model, the vibration from the ground is unknown. A load-dependent estimator is proposed to estimate the state vector when the system is subject to unknown input and measurement noise. By imposing some constraints on the estimator parameters, an estimation error dynamics is derived. The asymptotical stability and the energy-to-peak performance are investigated for the derived estimation error dynamics. With the stability and energy-to-peak conditions, the design method for the estimator parameters is proposed. It infers from the simulation and comparison results that the designed estimator is effective and better than the well-known Luenberger estimator.

Keywords: active suspension systems; load-dependent observers; unknown input; energy-to-peak estimation; observer design; estimation error dynamics; vehicle suspension; quarter-car models; sprung mass; polytopic modelling; asymptotic stability; simulation.

DOI: 10.1504/IJVD.2015.071069

International Journal of Vehicle Design, 2015 Vol.68 No.1/2/3, pp.162 - 179

Received: 11 Jun 2014
Accepted: 21 Oct 2014
Published online: 11 Aug 2015 *

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