Active Vibration Control

TrelleborgVibracoustic’s unique Active Vibration Control (AVC) technology is an ideal solution to solve noise issues in hybrid cars. In the quest for fuel economy, engine cylinders are switched on and off in hybrid cars, causing varying vibrations and resulting noise levels. TrelleborgVibracoustic’s innovative active vibration control system out-performs traditional passive systems by monitoring and adjusting to sound levels, significantly contributing to improved driver comfort.

AVC monitors and adapts to changing noise and vibration conditions by incorporating a microphone in the cabin as an error sensor, rather than the traditional accelerometer mounted adjacent to the actuator. Data from the microphone is fed into an Electronic Control Unit (ECU) that sends a signal to an electromagnetic actuator or “shaker” located near mount attachment points (possible hot spots for vibration).  This “shaker” generates a wave of identical or directly proportional amplitude to the waveform of the original disturbance, but with opposite polarisation, creating the desired level of destructive interference to reduce or cancel the amplitude of the perceived noise or vibration.

Andrew Harrison, Project Manager Advance Engineering, says: “. Though vehicle drivers want to reap the benefits of improved fuel economy that a hybrid car offers, they still want to enjoy their driver comfort, especially the level and consistency of noise. Our advanced active system allows original equipment manufacturers to monitor and manage a controlled driving experience.”

 

AVC can be used on any engine type but is especially suited to hybrid vehicles that include a combustion engine. The system includes a closed loop controller, CAN interface, bespoke user interface software, superior IO protection, integrated accelerometer and USCAR connector plus advanced electromagnetic actuator.

 

In addition, TrelleborgVibracoustic’s AVC system uses the “voice coil” approach within the electromagnetic actuator.  Inertial voice coil shakers employ a permanent magnet that helps them to move quickly and therefore deal more effectively with higher frequencies, as well as the lower frequencies found at idle. This makes them ideal for dealing with booming 2nd and 4th order sounds and vibrations in addition to idle concerns.

TrelleborgVibracoustic’s AVC technology is rated to IP69K, a test specification for applications where high pressure and high temperature is used to sanitise equipment. It means that the system is resistant to high temperature, high pressure water jets and spray.  The AVC system can also replace the balance shaft, giving a significant overall weight reduction in the vehicle, contributing to further fuel efficiencies and cost savings.

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