Simulation and Parameter Optimization of Commercial Vehicle Cab Suspension System

Taking a commercial vehicle cab suspension system as the research focus, a rigid-flexible coupled dynamics model was established based on the nonlinear characteristics of the integrated damper air spring and bushings. Time-domain vibration acceleration signals were acquired at the connection points between the frame, cab, and suspension. The vibration signals at the frame and suspension connection points were input into the simulation model, where the vibration responses at the cab and suspension connection points were calculated and analyzed using the established cab suspension system model. The accuracy of the model was verified by comparing the simulation results with experimental data. The established cab suspension system model was further used to evaluate human vibration comfort within the cab, following national standards for subjective human perception. A piecewise polynomial function was employed to fit the stiffness-damping characteristics of the integrated damper air spring, resulting in the determination of the coefficients for each segment and the coordinates of the transition points in the fitting function. The total weighted root mean square (RMS) value of the cab floor acceleration was used as the optimization objective, while the coefficients and the coordinates of the breakpoints in the fitting function were employed as optimization variables. A multi-island genetic algorithm was applied to optimize the cab suspension's stiffness and damping properties. The optimization results indicate that the enhanced suspension system contributes to an improvement in cab ride comfort.