Study Of Vision Automatical Positioning System For CNC Machine Tools

With the rapid development of machine tool manufacturing industry,the degree of automation of parts processing is becoming more and more perfect.However,the installation and positioning of the machined parts and workpieces are still manual and other non automation methods.The non automated clamping method not only increases the auxiliary time of the production process,reducing the clamping efficiency and clamping precision will have a greater impact on the level of operation of the staff.In order to solve these problems,this article is based on the research of traditional machine tool workpiece positioning,that the machine vision positioning technology is applied to the CNC machine tools workpiece clamping field,then completing the research and design of the whole positioning system software.First,this paper depend on the three degree of freedom CNC machine tools that is built on the laboratory,according to the characteristics of CNC machine tools,discussing the shortcomings of workpiece processing positioning,studying a vision automatic positioning system based on CNC machine tools.According to the requirements of the system implementation function,designing and making sure the structure scheme of the machine vision positioning system,completing parameter calculation and selection to the hardware equipment,building a test platform suitable for the subject.On this basis,the camera in vertical and horizontal directions is calibrated by using Calibration Training tool and Matlab script node in visual development module,and the content and process of digital image processing are also discussed,through the experimental analysis of different image processing algorithms to obtain the workpiece processing effect diagram,selecting that the optimal algorithm suitable for this paper.At the same time,in order to improve the quality of workpiece image edge detection,the image morphological processing is integrated into the traditional edge detection method,and obtain a better image processing effect map,after using the principle of Hough transform line detection fit the straight lineof workpiece edge,establishing the reference coordinate system and the actual coordinate system of the workpiece under the ideal position and the actual position,and compiling the measurement algorithm,extracting the relative position variable of the origin between coordinate systems,using the distance formula from point to line to calculate the height of tool nose to tool plane,completing tool alignment and zero correction in Z axis direction.Finally,this paper makes a design and analysis of the positioning system software,and write automatic positioning system software on the Lab VIEW platform,building a good man-machine interface,through analysis of experimental results and practical machining application of the workpiece,verify the feasibility of the whole positioning system software and the maneuverability of the positioning method.