Research Of Tool Presetting And Measuring Machine Based On CCD Imaging

With the rapid development of mechanical fabrication industry, the numerical control processing center has been widely used by manufacturers. The TPMM (Tool Presetting and Measuring Machine) is used to preset tools by measuring the cutting point coordinates, angles, radius parameters of tools. To ensure the processing precision TPMM is crucial in the numerical control processing.The TPMM based on CCD imaging founds its technical base on machine vision inspection. It integrates applied optics, electronics technology and precision measurement technology, so that it possesses high precision and automation. Most such commercially available products as TPMM are made by foreign manufacturers, the homemade TPMM are all of optical projection mode carried out by human sight aiming; the optical projection mode suffers from subjective errors and is time consuming, so that precision and efficiency of the measurement are compromised. The project"Research of Tool Presetting and Measuring Machine Based on CCD Imaging"is to develop such an instrument.The main research works are listed as follows.1. The design and implementation of the mechanical system, the vision system and the software system of the TPMM are accomplished. The overall test of the instrument is performed. The error sources of all kind are analyzed. The precision of the instrument conforms to the national standard. The performance of the TPMM is tested to be high through experiments and custom applications.2. This thesis investigates deeply into image processing techniques in image measuring system, which includes: image pre-processing, edge detection, contour tracing, tool identification, characteristic parameter extraction and so on. The algorithms are carefully chosen and optimized through experiments. Based on the analysis of imaging characteristics of CCD, a sub-pixel edge locating algorithm is introduced in this work, and its virtues of high speed and high-accuracy are demonstrated.3. This thesis puts forward a new calibration method for two-dimensional image measuring system. Experimental results show that the novel method can improve the precision and efficiency of the TPMM. In this method, a target with single characteristic point is adopted. The target is kept still when calibration is performed,...