Research On Visual Measurement Of Rocket Landing Gear Position And Attitude

In order to provide the box-type rocket launcher with the accurate position and attitude relationship of the rocket launcher's landing gear relative to the loading vehicle,this paper designs a monocular vision position and attitude measurement method based on a new feature mark.In this paper,the nonlinear model of the camera is established by introducing distortion,and the conversion from three-dimensional coordinates in space to two-dimensional coordinates in image plane is completed.The principle of pose calculation is explained and the EPNP algorithm is selected as the pose calculation algorithm.Then,in order to improve the problem of the chaotic and non-unique feature point sorting of the classic black and white checkerboard under large-angle deflection,a new type of feature mark combining the mark circle and the checkerboard was designed.In order to eliminate interference and quickly obtain image information,a corresponding design was designed.In order to detect the mark circle and its center quickly and accurately,a mark circle detection algorithm is designed;according to the characteristics of the checkerboard on the characteristic mark,a combination of Harris corner detection algorithm and checkerboard corner detection is designed A new checkerboard corner extraction algorithm for templates;a feature point sorting algorithm is designed according to the distribution law of feature points on the feature signs.Then use the MATLAB algorithm and the algorithm designed in this paper to carry out the pose measurement experiment,and verify the accuracy of the algorithm in this paper to meet the measurement accuracy requirements through comparative analysis.The target rotation experiment verifies the invariance of the sorting of the target designed in this paper under largeangle rotation and the stability and accuracy of the sorting algorithm.Finally,this paper uses the finite element method to analyze the landing gear,and obtains the deformation of the landing gear under different loads.After analysis,it is found that they cause less error in the position and attitude measurement.Further,the most suitable target is obtained according to the deformation of the landing gear.The installation position reduces the error interference caused by the deformation of the landing gear.