Abstract
This paper proposes a method to control vibrations of an automotive drive system which has backlash. Backlash of the differential gear in automotive drive systems exacerbates the vibration control performance. Concretely, a shock torque generated by dead zone band characteristics amplifies the vibration amplitude and prevents the model-based controller from suppressing transient responses completely. Especially, when engine torque changes drastically, torsional vibration is excited due to the backlash and disturbs driving performance and riding comfort. Therefore, it is necessary to develop a vibration control method to suppress the adverse effect due to backlash. The purpose of this research is to verify a convenient control logic suitable for implementation using experiments, which can evaluate the nonlinearity of backlash. In this study, a basic experimental device, which is dynamically equivalent to the original automotive drive system, is constructed to verify control systems. The structure of the device emphasizes the vibration problems due to backlash in actual vehicles. To design a model-based controller, functional modeling approach is applied for system modeling. Using this approach, a nonlinear system can be modeled in the form of a linear state equation. Then, a controller is designed based on the linear model-based controller. Regarding proposed compensation for backlash, a convenient control mode switching technique, which utilizes characteristics of actual vehicles such as a dead time, is applied to the model-based controller. Finally, the control system is verified by experiments using the basic experimental device.
