基于空间长度约束的坐标控制场精度增强方法

In order to achieve global orientation and precision control in large space geometric measurement, precision three-dimensional coordinate control field need to be established. Using a laser tracker to establish coordinate control field by single station is the most effective means recently. But in face of higher precision in local area, coordinate transform error between stations must be reduced in the process of global orientation, and precision of control field in the region must be enhanced. In this paper, by using high precision ranging interference of laser tracker, multiple spatial length standards are constructed with carbon fiber rods and target ball seats, and arranged flexibly in the desired region in the space. In the process of using a laser tracker to make redundant measurement of control points by multi-station, length standards are added as constraints to overcome space occlusion and optimize tracker angle measurement error, further improve the coordinate precision of control points used to construct length standard, thus enhance the local field measurement precision. The experimental results show that precision of global orientation is better than 0.04mm in the range of 10m with this method, meets high precision requirement of large space geometric measurement.