| With the increasing demand of high-speed transport equipment market, low-voltage electrical equipment(hereinafter referred to as the carrier for low-voltage electrical equipment) is widely used in high-speed vehicles, the requirements of quality and performance is also more and more important. With low voltage electrical appliances not only need to operate under static conditions, but also need to be able to apply under the condition of vibration and even shock. With regard to the reliability test of the low voltage electrical apparatus, the reliability test of the low voltage electrical apparatus under the condition of high speed and variable load is seldom studied. In this paper, with the background of high speed and variable load conditions by low-voltage electrical appliance reliability, the current research status of less testing method is not mature, we put the variable load vehicles to carriage tools table as the core of the loading with reliability testing system of low-voltage electrical appliances. This innovative use of three-dimensional vision positioning system instead of the traditional two-dimensional plane positioning, and the establishment of a variety of low voltage electric traction system based on binocular vision positioning system, it also can adapt to the test pieces of a variety of low voltage electric appliance positioning traction. The main contents of this paper are as follows:(1)In order to test the stability of carrying low-voltage electrical requirements, we designed a set of three-dimensional positioning mechanism with X, Y, Z axis, this traction mechanism can reach arbitrary space in a certain range. In order to ensure the stability of the test vehicle in vibration environment, we innovative design of 3D mobile station in vibration environment, fixed by way of screw and bolt mechanism fixed joint. According to the breaker traction movement requirements, established the traction force model of actuator by hook with Y axis rigidity, improved the accuracy of the traction mechanism tripping device under vibration and anti jamming ability.(2)Analysis of the working principle and composition of breaker mechanism of 3D vision positioning system based on machine vision, analysis and selection of system components, including light source, light microscope and binocular camera, image acquisition card, and build the image acquisition hardware platform.(3)According to the requirement of precise positioning of carriage tool table, we established the 3D positioning system based on binocular vision location, including the establishment of the conversion from the physical world into the mathematical model of the coordinate system, image distortion correction, camera calibration method and introduces the Zhang’s calibration method, for the internal and external parameters of the camera’s etc...(4)3D reconstruction of binocular vision positioning system, including image processing, feature point selection, stereo matching based on SIFT algorithm, finally come to the disparity map, the 3D coordinates of the target. In order to achieve a more accurate positioning traction, the matching of feature points is accurate to sub pixel level.Through the system debugging, we proved this carriage tools table is designed to operate in the world under the condition of feasibility. Carriage tools table under vibration can be well fixed carrying, binocular vision positioning system can accurately calculate the breaker node coordinates, driving the mobile station moves to traction point, complete traction action. The positioning accuracy of the binocular vision positioning system reaches 0.02 mm, and the control accuracy of the system 0.05 mm is met. |
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