The Design And Implementation Of Engine Exhaust Noise Active Noise Control System

Under China's automotive industry and transportation cause rapid developments inevitably led to a substantial increase in our country's vehicle population. Wherein the engine exhaust noise occupies a very high proportion of the total traffic noise. It is possible to effectively control the engine exhaust noise of traffic noise pollution control have made significant contributions.Methods of today's automotive engine exhaust noise control include passive noise control, active noise control and complex noise control. However, due to the traditional low frequency region muffler noise effect is limited, and the conventional muffler exhaust pipe back pressure will increase to reduce the economy, the effect of low-frequency noise of the engine is significantly active noise control has been rapid development. System and Algorithm of Active Noise Control as the main contents of the subject. The main contents are as follows: 1) The thesis analyzes the basic structure of the ANC system types, describe in detail the various types of noise control system as well as the advantages and disadvantages of the basic principles of noise. As well as the principles of LMS adaptive filter algorithm is a brief analysis. 2) Depending on the nature of the engine exhaust noise analyzes the fed before narrowband ANC algorithm theory, specific trap method to analyze the waveform synthesis and adaptive. Details of the ANC while the secondary channel system problems and solutions proposed. 3) design of the engine exhaust noise ANC system hardware platform, expand the design from simulation engine exhaust duct means and the ANC controller hardware circuit in both directions. From the noise control algorithms, communication design, filter design, signal generator design and offline secondary channel estimation algorithms five aspects of the engine exhaust noise ANC system software design. 4) The engine exhaust noise ANC system experiments were designed to offline secondary channel estimation effect, single and multi-frequency noise reduction frequency noise reduction.