Optimal control of an 8-DOF vehicle active suspension system using Kalman observer

Article type: Research Article

Authors: Sadati, S. Hossein | Malekzadeh, Salar | Ghasemi, Masood

Affiliations: Department of Mechanical Engineering, K.N.Toosi University of Technology, 4th Tehranpars square, Tehran, Iran

Note: [] Corresponding author. Tel.: +98 911 3329757; Fax: +98 21 8882997; E-mail: [email protected]

Abstract: In this paper, an 8-DOF model including driver seat dynamics, subjected to random road disturbances is used in order to investigate the advantage of active over conventional passive suspension system. Force actuators are mounted parallel to the body suspensions and the driver seat suspension. An optimal control approach is taken in the active suspension used in the vehicle. The performance index for the optimal control design is a quantification of both ride comfort and road handling. To simulate the real road profile condition, stochastic inputs are applied. Due to practical limitations, not all the states of the system required for the state-feedback controller are measurable, and hence must be estimated with an observer. In this paper, to have the best estimation, an optimal Kalman observer is used. The simulation results indicate that an optimal observer-based controller causes both excellent ride comfort and road handling characteristics.

Keywords: Active suspension system, 8-DOF model, optimal control, passenger dynamics, ride comfort, Kalman observer, road disturbance

Journal: Shock and Vibration, vol. 15, no. 5, pp. 493-503, 2008