Research And Application Of Machine Vision In Cnc Machining Unit

In order to have high-quality and fast parts processed by CNC machine tools,in addition to relying on the performance of the machine tool itself and the processing code written,it is also necessary to place the parts on the processing station accurately.Under the current automated processing production line,it no longer relies on manual manual placement of parts into the processing station of the machine tool,and usually a robotic arm is used to place the workpiece for processing,so it is easy to have positional deviation problems of the parts placed in the processing station of the machine tool,thus It leads to the decline of the processing quality of the parts or even the processing failure,which affects the product quality and production efficiency.Therefore,a machine vision system solution is proposed to solve the above problems.The robotic arm is combined with machine vision technology to develop a visual CNC machining system.It mainly includes machine vision unit,CNC machining unit,robot unit and motion control unit.The vision unit can identify and locate the parts transported by the belt line.After processing,the coordinate position and angle information of the parts are transmitted to the motion control unit,and then processed by the motion control unit and transmitted to the robot unit.After the robot obtains the position information of the parts It can independently adjust the motion trajectory,accurately grasp the parts,and then correct the angle of the deflected parts,so as to ensure that the position of the parts is accurate when they are placed in the CNC machine tool processing station,thereby ensuring the processing quality of the CNC machine tool.It can be seen here that the accuracy of machine vision recognition and positioning determines the accuracy of the placement of machined parts,so the machine vision unit is particularly important.In order to ensure the reliability and stability of the system,in the processing of the visual unit,some noises are removed through RGB image conversion to grayscale,median filtering,etc.,and then when the image edge detection is completed,a Gaussian filter is used compared to the traditional Canny edge detection method.Some edge information is missing and the filtering is incomplete.An improved Canny algorithm is proposed,that is,the method based on wavelet transform and bilateral filtering replaces Gaussian filtering to complete image edge detection processing,and adds multiple directions to the gradient calculation formula.It ensures the accuracy of the final part positioning and identification.After completing the design of the entire system,the virtual simulation software IOA was used to build the scene of the visual CNC machining production line,and the four units covered in the system were added to it and simulated tests were carried out.The test results show that the machine vision unit can accurately locate and identify the parts transported by the belt line,and can output X,Y coordinates and R angle information,and then processed by the motion control unit,the robot can obtain the position and angle information of the parts,Complete the grabbing and correction of the parts,and accurately place the parts into the CNC machine tool processing station.After the CNC machine tool completes the processing,the robot takes the part and transfers it to the designated location.Finally,the control algorithm and operation process of the system are tested on the small solid desktop processing production line.The deflected parts can also be placed in the exact position after the angle correction by the vision system and the robot,and are processed smoothly.The product quality is qualified,and the reliability of the system has been verified.