An application of digital control technique for vibration fatigue test of automobile exhaust system

Abstract

Recently application of random vibration technique is becoming popular in accordance with development of digital control and fast fourier transformation techniques. In this paper some application of them for automobiles were considered. To fulfill the emission control regulation, most of the automobiles introduced catalytic convertor into the exhaust system which is becoming very important component and whose reliability must be good enough to vibration fatigue. The vibration characteristic of exhaust system has many resonances at relatively low frequency range. Therefore it is necessary to excite by random wave form at the vibration fatigue test in order to simulate real driving condition. To control random wave form precisely, digital control technique was applied. As a result many improvements were obtained in excitation control. In this paper general outline of control system will be discussed theoretically and experimentally.