Motor vehicle safety researchers have used the Phase 4 vehicle simulation model for several years. Because of its popularity and ability to simulate the three-dimensional (3-D) dynamics of commercial vehicles (large trucks and truck tractors towing up to three trailers), the Phase 4 model was ported to the Human-Vehicle-Environment (HVE) simulation platform. The resulting model is called Engineering Dynamics Vehicle Dynamics Simulator (EDVDS). This paper describes the procedures used in porting Phase 4 to the HVE platform. As a result of several assumptions made during the development of Phase 4, the port to EDVDS required substantial changes. The most significant modeling difference is the removal of the small angle assumption, allowing researchers to study complete vehicle rollover. Also significant is EDVDS's use of HVE's 'Get Surface Info' function, allowing the vehicles' tires to travel over any 3-D terrain of arbitrary complexity. These and other changes in the model are described in the paper. The paper also includes a validation study, comparing Phase 4 and EDVDS simulation results. For most manoeuvres, the results are quite similar. Differences become apparent as the manoeuvres became more severe, owing to the removal of the small angle assumption and extensions to the tire model. (A)
Abstract