针对大尺度空间中构件特征隐藏区的空间坐标测量, 提出了一种基于无衍射光束的测量探针, 并将该探针与全站仪结合构成了空间坐标组合测量系统。介绍了探针姿态测量系统和组合测量系统的结构与原理。测量时, 首先将探针测头接触于被测点, 并用全站仪或激光跟踪仪瞄准探针的光学系统, 测得探针的空间位置坐标。接着, 使用探针将测距激光通过axicon透镜变换为无衍射光, 并由CCD摄像机获得图像。由无衍射光的中心一对一映射激光的入射方向, 通过无衍射光图像定中计算, 获得探针的水平角和俯仰角。最后, 通过电子倾角仪测得探针滚动角; 联合测得各姿态角和位置坐标, 通过坐标变换, 计算得出被测点的空间坐标。实验显示, 该探针的姿态角测量精度为1 mrad, 组合测量空间位置偏差为±1 mm, 表明基于无衍射光束的探针与全站仪所构成的组合测量系统可满足大尺度空间中特征隐藏区空间坐标测量的要求。

A non-diffracting beam based probe was proposed, then the probe was integrated with a total station to form a combined measurement system for measuring space coordinates of hidden parts in a large-scale space. The constructs and principles of the optical probe for measuring spatial attitude and the combined measurement system were introduced, and the mapping relationships between the centre position of non-diffracting and the incident angle of laser was established. In the combined measurement system, the probe stylus was first set to touch the point of measurement, and the optical system of the probe was targeted by the total station or the laser tracker to measure the spatial coordinates of the probe. The laser beam to measure the distance was transformed into a non-diffracting beam through the axicon lens, and CCD images were produced. The center of the non-diffracting beam was mapped one to one to the incident direction of the laser, and the horizontal angle and the pitching angle of the probe were obtained via center fitting of the non-diffracting images. Finally, an inclinometer was used to measure the rolling angle of the probe, and the spatial coordinates of the measured point were obtained by combing all the measured attitude angles with the position coordinates and coordinate transformation. Experimental results indicate that the precisions of probe's attitude-measuring system and combing measurement system are 1 mrad and ±1 mm, respectively, which demonstrates that the combined system is more flexible and reliable and meets the measuring demands of space coordinates of hidden parts in large-scale spaces.