Aluminum Sheet Laser Thickness Measurement System Data Processing Based On Wavelet Analysis

With the development of economy and technology, the requirement of thin aluminum strap increased largely, to produce the high precision thin aluminum strap, the thickness measure equipment that must possess of 0.001mm measure precision is needed, so that it can meet the requirement of the thickness control. The on line measure equipment that based on laser technology have characters of low cost, high precision and good stability, it is very important to improve the quality of aluminum strap and enhance the market competition. But affected by the industrial environment, the obtained data involve a lot noise pollution, those noise affect the precision badly, so the data processing is very important to insure the precision. Therefore, the wavelets analysis is introduced to the dada processing of laser thickness measurement in this paper, and analyzed the error souse and error type who affected the system's precision, and established a data processing step, then calculate and compare the precision. In this paper, the data processing of the laser thickness measurement system has been studied as follows:1. Using the data of industrial and loading specifically frequency vibration experimentations, the error factors that affect the system are affirmed, and make sure the relationship between the precision and frequency.2. Choosing the sampling frequency, study the data pretreatment method, and apply it to the testing data, check up the pretreatment effect.3. Using the Multi-resolution Analysis(MRA) wavelet theory in eliminate noise, the after-treatment of the pretreatment data will be made, then calculate the parameters that only adapt to this laser thickness measurement system, compare the precision before processing and after processing.4. Apply the wavelet package to the data processing with it's characteristic of analyzing high frequency signals, calculate the parameters, compare the precisions that result from MRA wavelet de-noise and wavelet package de-noise.5. Founding a data processing step and choosing the parameters, apply to the testing data processing, analyzing the system precision change, proving the validity of the data processing method.