Vehicle dynamics simulation using bond graphs

This work addresses the construction of a fourwheel, nonlinear vehicle dynamic bond graph model and its implementation in the 20sim modeling and simulation environment. Nonlinear effects arising from the coupling of vertical, longitudinal and lateral vehicle dynamics, as well as geometric nonlinearities coming from the suspension system are taken into account. Transmission and (a simplified) engine models are also included. The modeling task is supported by a multibody representation where the parts are handled as rigid bodies linked by joints. The first step is the 3D-modeling of each, chassis, suspension units, tires and joints, as bond graph elements equipped with power ports for physical interconnection. This is done with the help of vector or multibond graphs in order to exploit their compactness and simplicity of representation. These 3D-units are later programmed as 20sim bond graph subsystems whose assembling through the power ports allows for an automated, modular approach to the construction of the overall vehicle model. Simulation experiments corresponding to standard vehicle dynamics tests are presented in order to show the performance of the model. Index Terms — Bond Graphs, Multibody systems, Vehicle dynamics.