Development of a 7-DOF Vehicle Vibration Simulation Model

This paper presents a method for developing a seven-degree-of-freedom (7-DOF) vehicle vibration simulation model based on multibody system dynamics principles. The model is implemented to conduct an in-depth analysis of ride comfort for a specific vehicle. Technically, we first construct the vehicle's rigid-body model, incorporating various road profiles encountered during driving and their impacts on the vehicle body. The implementation involves defining mass properties, inertia tensors, and constraint equations using matrix formulations. Subsequently, we introduce seven degrees of freedom: translational motion, pitch, yaw, roll, and rotational motions about the X, Y, and Z axes of the vehicle body. These DOFs are implemented through coordinate transformation matrices and generalized coordinate vectors in the dynamic equations. The numerical integration of equations of motion employs Runge-Kutta methods for stability. Finally, ride comfort simulation results demonstrate the correctness of our modeling methodology, numerical computation stability, and feasibility of design outcomes. The code architecture includes modules for road excitation input, force calculation, and vibration response output. Future research will integrate additional factors such as velocity and payload variations through parameterized scripting to enhance vibration behavior prediction accuracy.