An explicit integration method for realtime simulation of multibody vehicle models

Abstract

High performance computers have been used for realtime simulation of multibody vehicle dynamics models consisting of many bodies and joints, a powertrain model, antiroll bars, and tires. This research proposes an efficient implementation algorithm for explicit numerical integration methods so that relatively low cost computers can be used for the realtime simulation of the multibody vehicle dynamics models. Newton chord method is employed to solve the equations of motion and constraints. The equations of motion and constraints are formulated such that the Jacobian matrix for Newton chord method is needed to be computed only once for a dynamic analysis. Numerical experiments showed that the Jacobian matrix generated at the initial time could have been utilized for the Newton chord iterations throughout simulations under various driving conditions. Convergence analysis of Newton chord method with the proposed Jacobian updating method is carried out. The proposed algorithm yielded almost exact solutions for a prototype vehicle multibody model in realtime on a 400 MHz PC compatible.