Abstract
A tractor-semitrailer vehicle modelled as a discrete-continuous vibrating system and subject to a randomly profiled road is presented. The potential performance benefits of active damping and load leveling between the cab and tractor frame are investigated. A parameter optimization procedure is employed to design the active suspension system. The performance index includes a weighted sum of the variance of human perception acceleration and the variance of cab suspension dynamic deflections. It is shown that significant improvements in the cab vertical and longitudinal accelerations can be achieved with the active suspension systems.