Research On Measurement Of Relative Pose Between Non-cooperative Targets In Short Range

The rendezvous and docking of non-cooperative targets in space is an important issue to beconfronted and solved in manned space development. In this issue, the measurement of relative poseis a key technology. The research on measurement of relative pose between non-cooperatives targetsin short range will be performed in this paper.First, the measurement method of relative pose based on binocular stereo vision is proposed forthis purpose. In real conditions, the existing errors affect a lot in the relationship model between depthand disparity. A general model of depth and disparity applying to any configuration in binocular stereovision system is proposed to achieve depth recovery and3D reconstruction. The experiment resultsdemonstrate that the relative error is reduced from35mm to12mm in the distance of1400mmcompared with the traditional binocular camera calibration method. Meanwhile, the outdoorexperiments have been performed to verify the accuracy and robustness of the new method.Second, a measurement algorithm of relative pose based on stereo vision is proposed withestablishment of the new method. The spacecraft windsurfing is used as the identification target. Thelinear feature of spacecraft will be obtained after the median filtering, edge detection and Houghtransform. Also, the boundary and four vertices of rectangle can be acquired after the judgment.Following the stereo matching and3D reconstruction based on the new method, we can get the worldcoordinate of feature points, following the position and attitude. The experiment results show that thepose error is maintained at less than2°which has a50percent increase than the current method andcan meet the demand of the spacecraft tracking.Finally, the pose calculation method based on laser scanning is introduced for the problem ofstereo vision and the overall program combined stereo vision with laser scanning technology isproposed in this paper. The program includes the analysis and selection of sensors, the hardwareconfiguration, layout and workflow of system. Meanwhile, the accuracy and feasibility is validatedthrough real2D scan data. The program combines rich image information in stereo vision as well asprecise distance and attitude information in laser scanner which can propose a new method forachieving precise and full range measurement of relative pose in non-cooperative targets in space.