128 Int. J. Vehicle Systems Modelling and Testing, Vol. 2, No. 2, 2007 Copyright © 2007 Inderscience Enterprises Ltd. Parameter identification of a suspension system and road disturbance estimation P. Gáspár*, Z. Szabó and J. Bokor Computer and Automation Research Institute, Hungarian Academy of Sciences, Kende u. 13-17, H-1111 Budapest, Hungary Fax: +36-1466-7503 E-mail: gaspar@sztaki.hu E-mail: szaboz@decst.scl.sztaki.hu E-mail: bokor@sztaki.hu *Corresponding author Abstract: An identification method is presented for the parameters of a quasi Linear Parameter Varying (qLPV) model of a quarter car suspension system where non-linear components are taken into consideration. Because not all the variables necessary for the identification are measured, some numerical techniques need to be applied, e.g., the numerical integration of measured signals. It is also shown that the selection of the sampling time might be critical in this type of application. By using the result of this identification an algorithm is given for the road disturbance reconstruction. The road roughness estimation is based on this reconstructed signal. Keywords: linear parameter varying control; LPV; non-linear modelling; robust control; uncertainty structure; road vehicle. Reference to this paper should be made as follows: Gáspár, P., Szabó, Z. and Bokor, J. (2007) ‘Parameter identification of a suspension system and road disturbance estimation’, Int. J. Vehicle Systems Modelling and Testing, Vol. 2, No. 2, pp.128–137. Biographical notes: Péter Gáspár received both the MSc and PhD Degrees from the Faculty of Mechanical Engineering, Budapest University of Technology and Economics in 1985 and 1997, respectively. Since 1990, he has been a senior research fellow in the Systems and Control Laboratory of the Computer and Automation Research Institute, Hungarian Academy of Sciences. He is also an Associate Professor at the Control and Transport Automation Department, Budapest University of Technology and Economics. His research interests include linear and non-linear systems, robust control, system identification and identification for control. His industrial work has involved mechanical systems and vehicle structures. Zoltán Szabó received both the MSc and PhD Degrees from the Faculty of Sciences, Eotvos Lorand University, in 1991 and 2003, respectively. Since 2003 he has been a senior research fellow in the Systems and Control Laboratory of the Computer and Automation Research Institute, Hungarian Academy of Sciences. His research interests include system identification, LTV, LPV and bilinear systems, fault tolerant and reconfigurable control. His industrial work has involved mechanical systems and vehicle structures. József Bokor received the PhD Degree from the Faculty of Electrical Engineering, Budapest University of Technology and Economics in 1983, and the DSc Degree in control from the Hungarian Academy of Sciences in 1990. Presently he is the Deputy Director for Scientific Affairs at the Computer and