关节式坐标测量机结构参数标定优化采样策略

摘要

利用高斯一牛顿法求解便携关节式坐标测量机的标定参数时，其参数的可辨识性与Jacobin矩阵的条件数有关，而Jacobin矩阵的条件数决定于标定采样点的坐标。因此，必须对参数标定的采样策略进行优化。文中以锥孔标准杆件标定法为例，提出一种优化的采样策略来增大各个关节取值范围，从而使条件数最小化。经实验验证，采用这种优化采样策略标定提高了测量系统的精度。%We use the Gauss-Newton method to find the parameters in the parameters calibration for PCMM （Portable Coordinate Measuring Machine）. Then we find the relationship between the identification of parameters and the conditions numbers of Jacobin Matrix, and in practical the conditions numbers of Jacobin Matrix depends on the sample point. Therefore, the sampling strategy must be optimized. Using the cone and standard bar as a calibra- tion standard, this paper presents an optimized sampling strategy to increase the value range of each joint and thus minimize the conditions number of Jacobin Matrix. Experiment results show that the sampling strategy of calibration greatly improves the measurement accuracy.