Key Technology Research Of Tool Presetting And Measuring Instrument

Tool presetting and measuring instrument is the necessary equipment of CNC machine tools and machining center. As CNC machine tools and machining centers become popular application increasingly. The tool presetting and measuring instrument which can quickly and accurately measuring tool's parameters increasing demand. Our country's tool presetting and measuring instrument is also using optical projection principle to measure which rely on the human eye's aiming. This method not only measuring slow but also brings much subjective error, and has seriously affected production efficiency. However Tool presetting and measuring instrument based on Photoelectric in foreign country not only can automatically identify tool cutting point for measurement, but also measure tool's angle, arc radius, and other parameters, with a communications interface to processing equipment, measurement results can be directly conveyed to the processing equipment.Because optical measuring instrument have advantages of high degree of automation and diversification of measurement parameters. Recent years optical measuring instrument have also developed by domestic manufacturers but now a rare products. The design study by the key technology is the traditional optical projection tool presetting and measuring instrument into a photoelectric instrument and achieving photoelectric instrument was produced by ourselves. Photoelectric tool presetting and measuring instrument is a cutter parameters measuring instruments which based on the computer vision principle and set optical, mechanical, electronics, computers, precision measurement technology into one, can measure tool's size which NC processing needs quickly. Following the completion of the main research work:1. The tool presetting and measuring instrument overall structure design was completed. Analysis the system components of tool presetting and measuring instrument and the various components of the role, the relationship between them and pointed out specific requirements of them. We improve the traditional instrument system, installation of a two-dimensional CMOS Digital Camera, according to the precision of the instruments required to complete the design of the optical lens for imaging, Displacement Detection Equipment determined and lighting system was reformed.2. The image preprocessing algorithms were studied. The mainly image preprocessing algorithms as follows: color images to gray algorithms, vary kinds of filtering algorithms.3. Relevant algorithm of tool feature points extracting was researched. Detailed discussion of the image segmentation algorithms and sub-pixel edge extraction algorithms. Different filtering algorithm and sub-pixel extraction algorithms were combined to carry out sub-pixel extraction experiments. Presents a sub-pixel edge Extraction Method—Determine the edge at pixel level ,through the combination of threshold segmentation and edge differential defined pixel, and then extraction of sub-pixel edge use polynomial fitting.4. Studied camera calibration theory and complete of the design of the calibration method. Proposes a kind of calibration model for the system. Research of the focusing evaluation function in-depth and presents a focusing evaluation method based on the width of the edge.5. Through VC + + software technology to solve the knife-image's real-time display, data processing, the preservation of the apparatus' state parameters, management of tool measurement results as well as the print of the measurement report. Achieved to prevent illegal copying of software through software technology.6. The error sources of the tool presetting and measuring instrument were analyzed, and the necessary experiments were implemented.