Abstract:

The nonlinear least squares method is used as the superior algorithm in PCMM calibration process.The concept of sampling coverage is proposed in the paper to assess the adequacy of sampling data.The angular range and the sampling angle are the necessary factors to obtain the sampling coverage of each joint.The value of the affecting factor of each joint angle respected to the final measurement accuracy is calculated by simulation experiments firstly.Joint 1 and joint 2 with the biggest weights are found out and compared with experiments,which show that better sampling coverage leads to fuller sampling with more accurate measuring results.

Key words: calibration;sampling coverage;angle variable;weight