激光跟踪视觉导引测量系统的全局校准方法  

Global calibration method for laser-tracking measurement system based on vision guiding

作　　者：魏振忠[1] 孙文[1] 张广军[1] 任少盟[1] 

机构地区：[1]精密光机电一体化技术教育部重点实验室北京航空航天大学,北京100191

出　　处：《仪器仪表学报》2009年第11期2262-2267,共6页Chinese Journal of Scientific Instrument

基　　金：国家863重点基金(2008AA042410);国家自然科学基金(50875014);教育部新世纪优秀人才(NCET-07-00043)资助项目

摘　　要：针对柔性装配中现有激光跟踪测量系统存在效率低、成本高、自动化程度低等问题,提出用单目视觉系统联合激光跟踪仪实现大尺寸组合式自主导引测量。为实现该系统的全局校准,提出了一种新的基于平面的全局校准方法,该方法通过获取靶标平面分别在视觉系统和激光跟踪仪坐标系中的平面方程,求解两坐标系间转换矩阵,完成系统全局校准。建立了数学模型,进行了算法仿真和全局校准实验。实验中测量30个不同位姿的平面靶标,并进行全局校准。结果表明,该方法操作简单,稳定性强,有实际应用价值,校准后平面法向量夹角、原点到平面距离的RMS误差分别为0.13°和1.50mm。Aiming at the problems of low efficiency, low automatization and high cost existing in traditional laser tracking measurement system widely used in digital flexible assembly technique, a combined homing measurement system for large-scale part assembly is proposed. A laser tracker and a monocular vision system are combined in the system to fulfill the homing measurement of 3D coordinates of benchmarks in parts. To calibrate the system, a new global calibration method based on spatial planes is proposed. Global calibration is fulfilled by acquiring plane equations of planar target at diverse positions and orientations in the coordinate frames of both the vision system and laser tracker respectively, and calculating the transformation matrix between the two coordinate frames. The data measured in the vision system are then combined with those measured in the laser tracker. A mathematical model was established, and simulation was carried out. To evaluate the precision of the method, global calibration experiment was accomplished. The plane equations of planar target measured at 30 diverse positions and orientations were taken into calibration. Experiment results show that this method features simple opera- tion, high stability and bright future for practical application; the RMS errors for the angle between planes measured by the calibrated vision system and laser tracker, and the distance difference between laser tracker origin and the planes are 0.13°and 1.50 mm, respectively.

关 键 词：全局校准 视觉导引 激光跟踪仪 柔性装配 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]