Research On The Method Of Laser Tracker On Measure Target Ball Automatic Positioning Based On Computer Vision

Aircraft parts assembly need precise parts measurement. At the moment a laser tracker is oftenused to make the measurement in the process of the assembling of the parts, the traditional lasertracking measurement need manual operation for laser, by this measuring way the efficiency is low,the process is complex. It’s difficult to meet the requirements of the digital automatic assembly. Thearticle based on the process of laser tracker on measuring target ball automatic positioning andmeasuring as the research object, based on machine vision research an automatic positioning methodof laser tracker on measurement target ball, combine the laser tracking measurement technology andmachine visual technology and precision turntable control technology, set upvisual laser tracker on measurement target ball automatic positioning system, and then accomplish thecorresponding experiments. Results show that, the method of visual laser tracker on measurementtarget ball automatic positioning this paper put forward has good feasibility. Paper main researchcontent and work includes the following aspects:1） A laser initial guidance model based on camera Angle is designed, and analyzed bymathematics. The hardware structure of automatic positioning system is introduceddetailedly, including the control of turntable camera search subsystem and theprinciple of laser tracking measurement.2） The method of image processing to detection and track laser is analyzed deeply.The two kinds of noise model and the smooth filtering method of these two kindsof noise is researched. The frame difference method for laser automatic detectionand the gravity method for laser barycentric coordinates calculation is used. In thecoarse positioning process of the laser on the target point, the laser image issegmented by the OTSU automatic threshold method, the laser is tracked andposition real-timely by the method of gate tracking. Finally, the morphologyprocessing method for the optimization of the laser spot is researched.3） A mathematical model of the laser movement is constructed and analyzed. Themethod of the laser on the target ball aimed automatically for the laser tracker isresearched. Two kinds of automatic aiming model for coarse positioning isdesigned and analyzed.4） A laser tracker visual positioning software used to implement the laser tracking thetarget measuring ball automatic positioning is designed and developed. A hardwaresystem based on the method is built, and the function verification is realized. Finally, the error based on the initial guide efficiency and target positioningaccuracy is analyzed.