Research On Machine Vision Technology For6-DOF Space Docking

There are some kinds of large-aperture-optical in solid-state lasers device forresearching Inertial Confinement Fusion, which need to be stalled from t bottom to Top inthe optical path. The optical with large quantities and varieties are different in size,structure and weigh, their position and attitude should be adjusted during the opticalmodule assembly and calibration process.According to the assembly and calibration system in NIF, an automatic program foradjusting modules’ position and attitude was used to meet the requirements of theinstallation based on Machine vision technology. The original program with excessartificial interference was replaced by the new plan，and the level of assembly efficiencyand automation are improved in the optical module installation process.The hardware components, software process, main features and works, as well asimage pre-processing principles and algorithms in machine vision system was introducedin this issue. Besides, the coordinates of measured point was simplified as the point of thecenter of the circular identifies, and the algorithm suitable for the center of the circleidentifies such as image denoising, binarization, pixel and sub-pixel distinguish on edgedetection was used in image processing. At last accurate coordinates of the center of thecircle in the world coordinate system was obtained by final image filtering.Binocular image matching in two camera is a very important techniques intwo-dimensional coordinates conversed into three-dimensional coordinates by machinevision technology. Binocular stereo vision was designed for machine vision system withgrating projection technique.It was use to measuring optical module instead of artificialvision, with advantage of high accuracy, high speed and non-contact measurement. Spacedocking program bring into this system can effectively overcome the subjectiveawareness of the impact of manual monitoring.To meet the needs of the optical module assembly and calibration and adjust itsposition and attitude, a hybrid six DOF docking platform program was used to solve theproblem of collision and stuck, which composed by planar adjustment problem andhorizontal adjustment problem. This hybrid program has the advantage of parallelmechanism such as high stiffness, high carrying capacity and high precision, at the sametime it has the advantage of serial mechanism such as easy kinematics analysis, flexiblebodies and large workspace.The position relationship between symbol and target was acquired by machine vision. It was introduced into inverse displacement solution of motors and platform center,and then we got restriction inequality of spatial position equation for workspace analysis.At last, a numerical example was studied and the workspace in different orientations wasderived by Matlab emulating analysis with the given mechanism parameters, and theavailability of workspace analysis was verified by spatial geometric method.