基于迭代的旋转视觉元件针脚位姿估计精度优化

Accuracy optimization of pin pose estimation based on iterative rotating vision

摘要:

高效率型插件机通过同步带拖动旋转轴，插件模块紧凑重量轻，但大角度转动时旋转角定位误差偏大，针对旋转角定位误差影响针脚位姿估计精度的问题，提出基于位置约束和迭代拟合的位姿估计精度优化方法；元件针脚的相对位置固定，因此旋转测量时所有针脚转过相同角度，且针脚轨迹为圆周，该方法根据这两种约束构造了圆轨迹拟合方程和旋转角拟合方程，通过迭代实施这两种拟合得到旋转角的精确估计值，从而实现了元件针脚位姿精密估计；为了验证本文方法的有效性，进行了理论分析和仿真，仿真结果表明该方法可抑制大角度转动时旋转角的定位误差的增大，在常用针脚元件及工作参数下，迭代仿真的位姿误差控制在±0.018mm之内，耗时低于65ms，精度和实时性均能满足异形插件机的实际需求。

Abstract:

The rotating shafts of high efficiency inserting machine are drive with synchronous belt, it makes the new design insertion module compact and light, but the error of shafts rotation increases when rotate large angle, this will degrade the estimation accuracy of pin pose. In order to solve this problem, a improved pose estimation method based on location constraints and iterative fitting is proposed. The pin of the component is fixed, so all pins pass same angle every time they rotate during rotation measurement, and the rotation trajectories of all the pins are on circles. Base on these two constraints, circular trajectory fitting function and rotation angle fitting function was constructed, by iteratively implementing these two fitting operations, accurate estimation of the rotation angle is obtained, as result the precise position estimation of component pin is achieved. To verify the proposed method, theoretical analysis and simulation was conducted, the results show that the method can restrain the increase of the shafts rotation error when rotate large angle. Under the common pin components and working parameters, the pose error of iterative simulation is controlled within ± 0.018mm and the time costs less than 65ms .The accuracy and efficiency of the proposed method can meet the requirements of automatic inserting machine.