Traffic Audio Detection

In this dissertation , a new method of traffic volume detection is presented. The noise signal of passing car is gathered through microphone array, and processed off line with array signal processing theory , thus traffic volume and up and down vehicles can be estimated accurately. The condition of current traffic volume detection methods is also analyzed. Subsequently, the primary knowledge of sound wave and the model of signal transmission are introduced .At last, the models of the narrowband and broadband array signal processing , the theory of the number of source signal estimation , the theory of invariable estimation and usage of high-order statistics in array signal processing are presented. In this paper, the problem of the number of vehicle estimation can be transformed into the number of signal source estimation, and the problem of up and down vehicles estimation can be transformed into DOA estimation alteration of array signal processing. As a result, we can get the traffic volume estimation and up and down vehicles estimation . At last, we prove that the method is feasible by experiment.