Analysis And Research Of Laser Spot Center Positioning

With the rapid development of industries such as industrial manufacturing and the continuous improvement of technological level,the measurement and positioning work has become increasingly important as a guarantee of product quality,and the realization of high-precision automatic positioning has become a research focus and difficulty.Compared with manual positioning,laser positioning has the advantages of high detection accuracy,good security and convenient operation,etc.,but the traditional laser center position detection algorithm has higher requirements on spot morphology,and when the spot appears a certain distortion,the calculation result may have a large error.Therefore,it is necessary to improve the precision of spot center detection under complex conditions to ensure the smooth completion of the measurement work.The main research content of this paper is the laser spot center detection technology,and the key parts such as spot image preprocessing and spot edge detection are also studied.The main work is as follows:1.Spot image preprocessing.According to the features of laser spot image,the adaptive image clipping method is used to remove invalid background and reduce the amount of computation;This paper analyzes and compares the ability of several filtering algorithms to suppress the image noise,and finally selects the bilateral filtering to denoise the laser spot image,which can effectively remove the image noise and protect the edge details.2.Spot edge detection.When the surface texture of the target irradiated by the laser is relatively complex,the laser spot will contain a lot of invalid information,which affect the accuracy of the center detection.Therefore,the classical edge detection operator is studied and analyzed,and improved based on the Canny operator.The internal background of light spot is eliminated by morphological treatment.Increasing the accuracy of edge positioning is increased by improving the gradient calculation method.The OTSU algorithm which is used to calculate the high and low thresholds has been improved to raise the edge detection efficiency.The experimental results show that the improved operator can detect the edge of the spot accurately and has a good performance in the continuity and singleness of the edge pixels.3.Spot center detection.Since spot image is prone to distortion and its energy distribution is in a non-ideal state,the spot center can be better detected by relying on the spot edge.Firstly,through the improved ellipse fitting method,the invalid edges in the distorted spot were removed,then the center point group was obtained by piecewise fitting according to the total number of pixels of the effective edges,and the Meanshift clustering processing was carried out to calculate the center coordinates of the light spot.4.Establishment of experimental platform.Appropriate hardware equipments were selected to complete camera calibration and the laser spot center positioning algorithm was verified.The experimental results show that the proposed algorithm can effectively detect the center coordinate of the spot under the condition of partial spot distortion.