Research On Pose Measurement Method Based On Planar Coding Target

Object position and attitude measurement is of great value in industrial fields such as aerospace,robot navigation,surgery,photoelectric sighting systems,and automotive quality inspection.Monocular vision pose measurement refers to the measurement of the geometric size of an object and the position and attitude of the object in space using only a single vision sensor to collect images.It has many advantages such as non-contact,simple structure and strong real-time performance.Aiming at the problem that common target pose measurement systems cannot take into account both high resolution and large field of view,this topic proposes a pose measurement method based on a plane-encoded target and establishes a corresponding pose measurement system.This system starts with a plane coding target as imaging targets.As long as the local information of the coding target is obtained,the imaging position in the target can be decoded,and then the position and attitude of the target can be obtained through image processing and spatial coordinate position transformation.Realizes visual posture measurement with a relatively small field of view and can perform high-precision measurement on a relatively large range of targets.It has high scientific research significance and practical value.The specific research work carried out in this paper is as follows:(1)The current research status of pose measurement is analyzed.In view of the situation that the current pose measurement system cannot take into account both the small field of view and the large area,it is proposed that the use of coding targets can measure a relatively large area moving object with a small field of view.(2)The overall design of the pose measurement system based on the coding target is completed.The key problems of the system and the important problems to be solved in this subject are analyzed.(3)The principle of pose measurement was studied.The design of the pose measurement system based on the coding target was completed.A model of the spatial coordinate relationship between the plane-encoded target image and the measured point was established,and the law of coordinate transmission of the encoded target was studied.The mathematical model of pose measurement was established and the model was optimized.Then the correctness of the model was verified by simulation,and influence degree of each factor on the pose measurement was analyzed to determine the best system parameters.(4)Parameter calibration in camera calibration was performed.A plane calibration board with a circular array was designed and manufactured.The calibration board images were segmented with local thresholds,and the calibration board circle array was sorted.The camera was calibrated using the Zhang Zhengyou calibration method,and the accuracy of the calibration results was evaluated using the reprojection method.(5)The position and attitude measurement system software based on the coding target was compiled,and a large number of experiments were designed and verified.The correctness of position and attitude measurement model and simulation analyses were verified and the system measurement accuracy was obtained.The experiments proved the accuracy of the coding target measurement system is better than ordinary target measurement system.