COMPARISONS OF A LINEAR WITH A NONLINEAR MULTIBODY SIMULATION OF AN OFF-ROAD VEHICLE

Over the past two decades there has been a great deal of research in the area of multibody dynamics and its application to the modelling of vehicles. Multibody dynamics formalisms can be categorized based upon several criteria. Of these, whether linear or non-linear equations-of-motion are generated by the technique is one of the most significant. In the Dynamics Laboratory in the Department of Mechanical Engineering at Queen's University both linear (A'GEM) and non-linear (REVS) programs for modelling road vehicles are used. A'GEM is based upon an influence coefficient technique and generates the linear equations-of-motion for systems with general topology. REVS is based upon Kane's Equation (The Principal of Virtual Power or Jourdain's Principle) and generates the non-linear equations-of-motion for systems with general topology. Both programs are implemented on personal computers. In this paper the results from models of a 1/4 ton off-road vehicle (the Iltis) developed with A'GEM and REVS are compared with each other. Comparisons between the models are made on the basis of accuracy and execution time which are the fundamental tradeoff variables between linear and non-linear equations.