Research On Audio Signal Characteristics Of Pavement Void Based On Time-frequency Analysis

Pavement void is one of the most common damages of cement concrete pavement. Theexistence of the pavement void can bring a serious impact on traffic safety. So it is veryimportant that detect the pavement void as early as possible. Acoustic-vibration testing is asimple and effective method for detecting. Acoustic-vibration testing is a simple and effectivemethod for detecting. Through exciting tested specimens, so as to produce mechanicalvibration. Then analysis the audio signal that collected, and expect to get more informationabout the pavement structure from the characteristics of the audio signal.In this paper, firstly collect50sets of audio signal from the10test pavement. Then usesendpoint detection method and the wavelet threshold de-noising method to process the audiosignal, in order to improve the accuracy of the signal analysis. Process the signal with themethod of Wigner-Ville distribution and Choi-Williams distribution. After analysis andcomparison, this paper choose the method of ChoiWilliams distribution which can suppressthe interference of the cross-term as the method of processing the audio signal. Through theanalysis of the time-frequency distribution chart, find out the differences and characteristicsbetween the audio signal of pavement with void and pavement with non void. Through theresult it can be known that by calculating the percentage of main frequency energy we can getthe information of the pavement void. But the percentage of main frequency energy isaffected by the parameter. The paper compares the different valve of the percentage ofmain frequency energy in the condition that the value of is different. Then get aappropriate value of. Then judge the pavement condition by calculating the energy of themain frequency.In the paper, through the test of50groups of audio signal, get the time-frequencydistribution charts of the signal and calculate the energy of the main frequency. Then thejudge the condition of pavement by the method that was given by the paper. And compare theresults with the actual pavement condition. The results show that this method can accuratelydetermine the codition of the pavement void.