Active vibration control of gearbox housing using inertial mass actuators

Reducing carbon emissions is a primary goal in the global effort to combat climate change. Decreasing the weight of a vehicle improves efficiency and significantly reduces emissions. One of the main contributors to the vehicle's weight is the gearbox. However, this approach presents a challenge as lightweight transmission systems experience higher vibrations and noise emission levels. In this paper, an economical active vibration control system is developed to control the vibration levels of an automotive gearbox housing. The gearbox's mounting points are targeted to reduce the transmitted vibrations to the car cabin. The active control system aims to target high-frequency vibrations between 1000 Hz and 5000 Hz. A compact piezoelectric inertial mass actuator is designed and tested on a gearbox-constructed setup that simulates the vibrations and noise similar to a commercial automotive transmission system. The developed test-rig is excited by a piezo stack actuator at the input shaft. Filtered-x least mean square algorithm is implemented on a high-speed microcontroller, and the vibration levels are significantly reduced using the active system. An average reduction of approximately 8.5 dB is achieved between 1000 Hz and 1500 Hz, an average reduction of approximately 14 dB is obtained between 1500 and 2000 Hz, and an average reduction of 10.8 dB is attained between 2500 and 5000 Hz.