1207 Active Muffler for Medium-Duty Diesel Vehicles Considering Thermal Influence and Control Trackability

The practical active exhaust muffler using ANC system was studied for reducing the harmonics of basic frequency which are the main components of exhaust noise generated by a medium-duty diesel engine truck during the period of acceleration. The muffler structure which reduces the thermal affect to ANC speaker by exhaust gas, was designed, and the time base Synchronized Filtered-X method with a modified variable stepsize algorithm was proposed as the control strategy in time-varying environment. The effectiveness are verified after applying the ANC system to the exhaust noise control of the truck on the condition of accelerated running.