AUTOMOBILE INTERNAL COMBUSTION ENGINE LOW FREQUENCY NOISE REDUCTION USING ACTIVE NOISE CONTROL SOLUTIONS

Increased level of automobile low-frequency noise may cause significant environmental pollution, driver and passenger discomfort etc. For automobile equipped with internal combustion engine forming of either internal or external noise is mainly caused by engine operation. Approaches to automobile low-frequency noise reduction are suggested using active noise control method. The different variants of principal schemes and constructions of electronic units of forming required vibroacoustic characteristic of active noise control system were developed by the author either for complex noise reduction of experimental unit or for investigation of the separate noise sources reduction. Intercommunication of engine compartment and passenger compartment and coherent low-frequency sound radiation by air-suctioning pipe and exhaust pipe are taking into consideration. Construction of active noise control unit designed by author for complex reduction of exhaust and intake engine low-frequency noise is described. The results described in this paper may be useful for further development and application of constructions of active noise control systems as for efficient complex engine noise reduction or for reduction of the separate automobile engine noise sources.