Research On The Adaptive Matching Algorithm For Laser Cut Mark Detection Signals

In criminal technology,cutting tool marks is one of the key directions of its research.Tool traces are the most common traces in many cases,for example,theft,robbery,murder.For the nature of the case,determine the crime tool,Confirmed that the suspect is of great significance.According to incomplete statistics,more than 70%of criminal cases have tools traces on the scene.The proportion of the tool marks about 80%In some areas.And tool traces also have not easy to damage,difficult to disguise,the emergence of high,good value of identification characteristics.The other types of traces are difficult to match these advantages.Therefore,it is of great practical significance to study the extraction and analysis of tool traces.In this thesis about Trace signal collection,the tool trace laser detection device based on Lab VIEW.Through the device can be collected the signal of the tool trace traces effectively.Due to reflection and the presence of uncontrollable factors such as devices in the process of collecting signals.So there will be abnormal data and the presence of noise in the acquired signal.In dealing with exception data,the K-Means algorithm is used to repair the abnormal data in the signal.And through the experimental simulation to verify that the algorithm for the cutting tool trace laser detection signal in the abnormal data has a good repair effect.In the signal noise reduction,this thesis focuses on the smoothing of the data by LOWESS(Local Weighted Regression Scatter Smoothing).Through this algorithm,the noise in the scanning data can be eliminated to the greatest extent.And it is to be verify the effectiveness of the algorithm through the experimental simulation.In similarity comparison.First,the characteristic signal of the smooth signal is extracted,the feature vector is subjected to vector processing.The comparison between the signals is converted to the calculation of the spatial distance.Finally,the dynamic programming is used to match the similarity.Get the final similarity size,and then determine the cutting tool.On the basis of theoretical research and experimental simulation,the trace signal is collected by means of a tool trace laser detection device.And then the combination of software implementation and test analysis,the algorithm proposed in this paper is verified,and then determine the validity and correctness of the algorithm.