Key Technologies Of Shield Attitude Measurement System

The positioning accuracy of CCD spot center plays a vital role in the laser targetShield attitude measurement, which directly affects the accuracy of the entiremeasurement system. In order to obtain high-precision measurement system,we proposedan attitude measurement system based on aperture imaging.The coordinate systems and posture elements in the shield attitude measurement isdescribed in this article. For the calculation of roll angle is dependent to the calculation ofpitch angle and horizontal angle, we can use iterative algorithm to determine the attitudeangle shield accurately, and then find the geographic coordinates of the Shield and the spotincision.The spot found by CCD occupied only a small part of the CCD image. in order toimprove the efficiency of the algorithm,we firstly conduct the coarse positioning of thelaser spot center and got the spot, we delineated a small region of interest (ROI)by thiscentre. In this paper,we used the median filter to eliminate noise and keep the edgecharacteristics of the image. We use the image opening and closing algorithm to filter thedark areas, thus we got high quality laser spot, and finished the image preprocessing..The center location algorithms based on gray and the common location algorithmsbased on the edge has poor immunity,does not meet the measurement requirements of thisarticle.In this paper, an edge detection algorithm based on the threshold gradient operatorusing the grayscale threshold to obtained the spot silhouette is proposed,the defects of spotcontour will seriously affect the accuracy of the measurements, we propose a leastsquares fitting algorithm based on rough fitting threshold method of to achieve sub-pixelpositioning of the laser spot.We also describes the character and parameters of the key components of the experimentalplatform, complete selection of target components by comparing and analyzing.Thecauses of error are deeply analysed on the basis of obtained experimental data.