Modeling and Tuning of Hydraulic Road Simulators for Heavy Vehicle Testing

While road simulators have seen wide use in the automotive industry, road simulation of large vehicles (20,000 lbs of larger) has been less widely applied. This area of research is important because of the disproportionate amount of damage done by heavier vehicles on our nations transportation infrastructure. Road simulation is an important tool in investigating factors involved in the dynamic forces imparted to pavements by these large vehicles. A four-axis electro-hydraulic road simulator is simulated and verified by experimental data, showing excellent correlation between modeled and actual response. We present the results of a study which determines the effects of system tuning on the ability of the system to adequately re-create the road conditions. Two system performance indices, dynamic load coefficient and total energy delivered to the unsprung mass are used to assess the effects of servo loop tuning on the road simulator performance.