Modular modeling and dynamic response analysis of a driveline system during start-up process

Abstract

This study is aimed at exploring the effect of the structural parameters of a driveline system on its dynamic response, during the start-up process. For this purpose, a modular modeling method was proposed, based on the power flow and mechanical connections in the driveline. Moreover, a dynamic model of the driveline for vehicle start-up was established, taking into consideration the time-varying mesh stiffness, shaft stiffness, damping, and the variation of the wet clutch friction coefficient with the relative slipping speed. Modal analysis of the driveline system was performed, and the influence of time-varying mesh stiffness of the gear set on the natural frequency was analyzed. Furthermore, an engine constant start-up control strategy was adopted, and the start-up process of the vehicle was simulated. The simulation model was verified with the experiment data. A new evaluation indicator was proposed taking into consideration the phase difference and amplitude change, induced by the time-varying stiffness and the self-excited vibration in the system. Lastly, the influence of the structural parameters on the dynamic response of the driveline system, during start-up, was investigated.