The Research Of The Grasp And Assemblage Of Moving Workpiece Based On Machine Vision

With the rapid development of computer technology and digital image processing,machine vision has been widely applied in the field of Automobile and automobile parts manufacturing,machinery processing industry.Recently the traditional industrial robots must go through with point by point teaching mode to complete handling,assembling and transfering material and up-down material in production line between the workpiece for each station.However the industrial field environment is complex,and the workpiece position is put randomly,so that the industrial robots can’t do operation task smoothly.According to the above problems,machine vision technology is introduced in this paper,and the mobile workpiece grabbing and assembling technology is studied based on machine vision.The main research work is as follows:(1)In order to solve the industrial products covering up and down automatic assembly in the production line,we complete the overall design scheme according to the technical index of the machine vision system,and the working principle of the machine vision system is introduced.(2)The monocular vision calibration methods is determined,and calibration of camera’s interior and exterior parameters is completed through the OpenCV,and image distortion is corrected by the calibration results.At the same time in order to get the relationship between the image pixel size and the actual physical size,subpixel level corner detection by interpolating diagonal point value on the basis of the Harris corner detector is completed.(3)Fixing the workpiece image processing,a algorithm based on rectangle fitting about centroid localization and the deflection angle is proposed.Because of the testing system for dynamic grabbing,workpiece movement fuzzy phenomenon is more serious with the improvement of motor speed.To remedy the situation,the wiener filter for image restoration is introduced.In order to solve the ringing in the restored image,we introduce the optimal window method put forward by Limetal,so that the processing result reinstated image edge is visible and avoid the ringing effect at the same time.(4)In Visual Studio 2008 with OpenCV2.4.4 software environment,the test system can be divided into four parts with modular design thinking,such as parameter setting module,image acquisition and processing module,motor control module,and communication module,each of which are expounded.Because the test software is more tasks,multi-threaded control technology is used to realize it at the same time.(5)In grabbing assembly experiment,to explore the following factors,such as light intensity,motor speed,which have a influence on the result of the assembly,experiments and record data are made respectively.According to the experimental data,every factor is analyzed and processed to ensure that the results of the final assembly are stable and reliable.