Research On Optical In-situ Precise Tool Setting System

In recent years,optical aspheric surfaces and free-form surfaces have developed rapidly.They are widely used in many fields,such as scientific research,national defense and military industry,industrial production and our daily life.The application of optical free-form surface is premised on the manufacture of optical free-form surface.How to improve the machining accuracy of optical free-form surface is a research hotspot and difficulty in the field of advanced manufacturing research.Ultra-precision single-point diamond turning technology is a machining method that can realize high-precision optical free-form surface.On the one hand,it's machining accuracy depends on the comprehensive error of the equipment itself.On the other hand,depends on the position alignment accuracy of the tool and the acquisition accuracy of diamond tool parameters.The cantilever beam type optical tool setting device commonly used at present has the problems of poor repeatability positioning precision,low resolution and the like.In addition,because the precision of the existing optical tool setting system is difficult to ensure the processing requirements,so after tool setting,it still needs to go through many trial cuts to carry out fine tool setting,which will inevitably lead to ineffective wear of the tool and reduce the production efficiency.Based on the ultra-precision single-point diamond turning machine tool as the research platform,aiming at the two shortcomings of low efficiency and tool wear of the traditional tool setting method,this article has researched on the in-situ detection method of diamond tool parameters.The main contents are as follows:1.This article proposed a new mechanical structure of diamond tool on-line detection system.The structure adopts cylindrical rotary support,which can achieve high repeatability positioning accuracy and avoid the disadvantage of poor repeatability positioning accuracy caused by gravity factors and repeated disassembly and assembly of the original cantilever beam mechanism's optical tool setting method.2.Based on the machine vision inspection technology,this article proposed a bidirectional optical inspection method for tool parameters.Optical inspection devices in X and Y directions are used to complete the measurement of tool tip space position and arc radius respectively at the same time,thus improving the inspection efficiency.3.Based on image processing technology,matrix theory,least square method and other basic mathematical knowledge,This article carried out the tool image preprocessing and sub-pixel edge detection,and the parameters of the tool are determined by combining the motion coordinates of the displacement mechanism in the system.4.Based on the principle of microscopic imaging system and telecentric optical system,this article proposed a calibration method suitable for microscopic telecentric optical measurement system.The traditional chessboard format calibration plate is replaced by a two-dimensional reticle with a fixed size,and the calibration error is less than 1?m.5.A diamond tool parameter in-situ testing experimental system is set up.Through the coordination of the hardware part of machine vision testing,image processing and displacement platform control software part,the image acquisition,processing and result storage of the single-point diamond tool are completed.The experimental results show that the optical in-situ precision tool setting system designed in this paper can realize the in-situ on-line detection of the tool,and the repeatability positioning accuracy is up to 1?m,which improves the detection accuracy and efficiency.