PERFORMANCE ANALYSIS OF A RELATIVE MOTION BASED MAGNETO-RHEOLOGICAL DAMPER CONTROLLER FOR SUSPENSION SEATS

摘要

A kineto-dynamic model of a suspension seat is formulated to account for contributions due to suspension kinematics. A regression-based model of a magneto-rheological (MR) fluid damper is also formulated and integrated to the suspension model. Two semi-active controllers based on the 'sky-hook' and 'relative states' are synthesized and simulations are performed to evaluate the shock and vibration performance of the MR suspension seat. The simulations are performed under an exponentially-decaying transient excitation with fundamental frequency in the vicinity of the suspension natural frequency, random excitations encountered at the seat base of vehicles with both low and high frequency components. The shock and vibration isolation properties of the suspension seat model are evaluated in terms of frequency-weighted rms accelerations and vibration dose values. Comparisons of the responses of the suspension seat model with 'sky-hook' and 'relative states' controllers revealed significant improvements compared to those of the passive suspension seat. The semi-active suspension seats could yield 19 to 40% reductions in the transmission of continuous vibration and 26 to 55% reduction of the shock motions. Both semi-active suspension models could considerably reduce the amount of end-stop impacts under high intensity excitations.