Automatic Micro-spot Welding System Based On Machine Vision Technology

Currently, in the manufacturing process of the electro-acoustic electronic devices, since the small size of these devices, so that the welding process is more complex, so usually miniature precision resistance spot welded. Traditional spot welding using handmade, not only the high labor costs, low welding efficiency and skill level of the operator due to inconsistencies resulting in uneven weld quality, in addition to workers’ is mobility and so on. In order to speed up production efficiency, reduce production costs and improve production quality. In this paper, we propose an automatic micro-spot welding system based on machine vision technology, described in detail the composition of the principle of the system, the core of the key software algorithms and software design specific programs.The main contents of this paper as follows:1. Based on the principles and structure of machine vision systems, detailed discussion of the selection method on cameras, lenses, lighting, computer configuration. And according to the automatic micro-spot welding system based on machine vision technology’needs analysis, combined with the task of welding object size, background color, speed and accuracy of detection and other factors, the project needs to select a suitable visual solutions.2. According to the process of image processing, discussed in detail the image processing of each step. The first step, the image preprocessing filter out interference information, enhance contrast, highlight the target area; the second step, the image segmentation get ROI region, and then use the Roberts operator extract the ROI edge contour information; The third step, for the obtained contour information carry out connectivity domain analysis, and according to the characteristic information of the target contour, extraction to obtain the weld line contour; the fourth step, the resulting weld line contour intersects with the reference line and obtains the coordinates of the midpoint of the two points of intersection,this point that is to be extracted spot position.3. After the image processing, the obtained spot’s coordinate is still located in the pixel coordinate system, also need to be calibrated for each coordinate system, so that the spot’s coordinate in the image can be converted to the motion platform coordinate system.In the first, this chapter discusses the definition and conversion of each coordinate system in detail.Second, introduced the intermediary conversion,saddle point. In the finally, on the premise of this theoretical basis, detailed analysis of the specific steps in this system about how to convert the spot welding from the image coordinate transformation into the moving platform coordinates.4. Software design and implementation of automatic micro-spot welding system based on machine vision technology .Discussed in detail the use of the software and vision package, design ideas, the concrete scheme of software design and method of operation.