Abstract
Powertrain is the largest excitation source of automotive noise & vibration. Frequency of the excitation source consists of two parts. One is engine rotation frequency and harmonics, the other is driver demanded propulsion torque including lower frequency. Vibration cause mechanism was analyzed for acceleration/ deceleration vibration (shock & jerk) and gear rattle which are related to lower and rotation frequency excitation respectively. Effective input torque profile shaping was investigated with a robust control approach. Amplitude of fluctuation torque input to transmission is the cause of gear rattle. Most effective and robust remedy for gear rattle is fluctuation amplitude reduction. A precompensator based on frequency property design is proposed to suppress the shock & jerk vibration. Robustness of control strategy is investigated with a resonance frequency shifted model. It is shown that resolution of control is depending on firing frequency and that is one of constraints for applying the strategy.
Keywords: Transmission, NVH, Gear rattle, Modelling, Active control