All vehicles with an internal combustion engine have a muffler located along the exhaust pipe, which helps to reduce acoustic noise emitted by the engine. Most mufflers are passive devices in which the exhaust gas route is laid through cameras and perforated pipes for filtering the frequency of acoustic vibrations without a significant preventing gas flow. Active sound suppression systems use one or more vibrating panels (essentially columns) given using a microprocessor. The microprocessor monitors the operation of the engine and / or acoustic frequencies, spreading in the exhaust pipe and forms a sound shifted in the phase with the noise created by the engine.
Active system for reducing exhaust noise
The principle is similar to the one that is used to suppress noise in headphones, only microphones and speakers used in automobile exhaust systems should be more powerful and able to withstand intensive heat and aggressive medium of the automobile exhaust. Active sound jamming systems can also be used to change the sound of a car engine, making a small engine sound more powerful or the sound of a diesel engine, like the sound of a gasoline engine.
Another advantage of active exhausting systems of exhaust sounds that they are relatively light and compact compared to a passive silencer, and can help reduce the weight of the vehicle. They can also help reduce the length of the exhaust pipe by saving additional weight and material costs.
Active suppression of exhaust noise is rare in cars today, but some manufacturers offer “active” exhaust systems. These systems are not trying to actively suppress the noise of the exhaust. Instead, they use electronic control valves to redirect exhaust gases through various paths in the exhaust system that causes the noise of the exhaust to have a different tone and / or amplitudes.
Sensors: microphone and / or connection to the engine control module. Executive mechanisms: durable high -temperature columns. Data transfer: usually CAN Tire. Manufacturers: EBERSPAecher