Abstract
Keywords - Vehicle dynamics, Suspension model, Multi-body dynamics, Real-time simulation, Kinematic and compliance test
Abstract - This paper presents an enhanced parametric vehicle dynamic modeling that includes kinematic and compliance characteristics of suspensions and shows then more accurately. The relative displacement and orientation of a wheel (toe, camber, side view spin angle, wheelbase, tread) with respect to car body are represented as a function of the vertical displacement of the wheel and steering input. This can be obtained from standard kinematic and compliance tests(K&C tests) of vehicle suspensions. A new functional suspension model is proposed as a kinematic describing function of the suspension, that represents the relative wheel displacement in polynomial form in terms of the vertical displacement of the wheel center and steering rack displacement. The relative velocity and acceleration of the wheel are represented in terms of the first and second derivatives of the kinematic describing function. The equations of motion for the full vehicle dynamic model are systematically derived using velocity transformation method of multi-body dynamics. The comparison of test and simulation results demonstrates the validity of the proposed functional suspension modeling method. The vehicle dynamics model based on the functional suspension model is computationally very efficient to achieve real-time simulation on TMS320 DSP board.