The evaluation of measurement uncertainty for laser tracker based on Monte Carlo method

The laser tracker is adopted the multi-station and time-sharing measurement principle to rapidly and accurately detect the precision of machine tool. In accordance with international standard, the measurement results should also give the corresponding measurement uncertainty. In the paper, the Monte Carlo method is used to evaluate the measurement uncertainty of laser tracker´s multi-station and time-sharing measurement. The N pseudo-measured data are generated by the measured ranging data of laser tracker, and the N calculation results of base point will be determined by the algorithm for base point calibration. It can obtain the measurement uncertain of ase point by calculating standard deviation of the N calculation results, then it can calculate the measurement uncertainty of each measuring point. The measurement uncertainty for the base point and measuring point can be comparatively accurately evaluated based on Monte Carlo method through less measurement times, meanwhile, it does not need to determine the uncertainty propagation coefficient of each error source, which bring great convenience in the actual calculation. Results of simulation and experiment shows the Monte Carlo method is an effective evaluation method of measurement uncertainty.