Active vibration suppression of automobile drive system considering effects due to variable control cycle

Abstract

This paper offers an active vibration suppression technique for automobile drive systems with backlash and limitation on the control cycle. The gear backlash in automotive drive systems causes undesired oscillations, which degrade the riding comfort, when a driving torque changes stepwise. In addition, an engine used as an actuator for the vibration control involves a limitation that makes the control cycle longer and time-varying due to the slow mechanical process to update the control input (i.e., engine torque). Consequently, an active vibration control system with compensation for the control cycle limitation is investigated in this paper. First, a drivetrain model, which is simplified to make it easy to evaluate only the effect due to backlash and the improvement by vibration control, is presented. The control cycle limitation whose only the negative effects are equivalent to those of a real engine is reproduced by applying program processing to command signals from a controller. To cope with the long cycle, the sampled-data controller, which can be designed without discretization, is used. In this paper, the sampled-data 𝐻𝐻_∞ controller is designed in consideration of the robustness. The time-varying effect induces the phase delay of the control input. Hence, predictive processing using the sampled-data controller and the unscented Kalman filter is introduced to compensate for the phase delay. Considering calculation loads, it is modified so that the number of iteration times of predictive simulation is reduced. Finally, simulation studies using the simplified drivetrain model verify the effectiveness of the proposed approach.