Flexible method for improved transmitter parameter calibration in accurate large-scale positioning system

An accurate large-scale positioning system is a three-dimensional workspace measuring and positioning the laser scanning-based system that is widely used in smart manufacturing and assembly applications. The system includes laser transmitters that are typically calibrated using one of two methods: a high-precision rotary table-dependent method or a three-dimensional (3-D) coordinate control network-dependent method. However, these methods are error-prone and inefficient. We propose a flexible calibration method that is based on the transmitter geometry and employs the characteristic angles of the transmitter as calibration targets that do not change with transmitter location or orientation. The proposed method also utilizes a calibration algorithm that is based on a highly precise 3-D coordinate control network and includes an optimization algorithm and an estimation algorithm to produce initial values. The results of Monte Carlo simulations indicate that the proposed method enables the characteristic angles to maintain accuracy within 3 arc sec. Furthermore, the results of verification experiments show that the proposed method decreases the deviation of each control point and the root-mean-square error to 0.075 and 0.052 mm, respectively.