Zhang Zhenyu, Ren Yongjie, Yang Linghui, Lin Jiarui, Shi Shendong, Zhu Jigui
State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China.
Sensors (Basel). 2019 May 7;19(9):2117. doi: 10.3390/s19092117.
In the measurement process of photoelectric scanning measurement network, the laser surface edge area has lower measurement accuracy than the middle area due to the geometrical distortions of the laser surface of the transmitter. This paper presents a sub-regional calibration method that can accomplish error compensation for the measurement system. Unlike the camera sub-regional calibration, the regional division and identification of the laser surface are more difficult. In this paper, the pitch angle in the transmitter coordinate frame of the spatial point was used as the basis for the division and identification of the laser surface. In the calibration process, the laser surface of the transmitter was divided into different regions and each region was calibrated independently, so that an intrinsic parameters database containing the intrinsic parameters of different regions could be established. Based on the database, the region identification and error compensation algorithm were designed, and comparison experiments were carried out. With the novel calibration method, the measurement accuracy of the system had an obvious upgrade, especially at the edges of the laser surface within a certain measurement area, which could enlarge the effective measurement area of the transmitter and would broaden and deepen the application fields of photoelectric scanning measurement network.
在光电扫描测量网络的测量过程中，由于发射器激光面的几何畸变，激光面边缘区域的测量精度低于中间区域。本文提出了一种能够对测量系统进行误差补偿的子区域校准方法。与相机子区域校准不同，激光面的区域划分和识别更加困难。本文以空间点在发射器坐标系中的俯仰角作为激光面划分和识别的依据。在校准过程中，将发射器的激光面划分为不同区域，并对每个区域进行独立校准，从而建立一个包含不同区域内禀参数的内禀参数数据库。基于该数据库，设计了区域识别和误差补偿算法，并进行了对比实验。采用这种新型校准方法后，系统的测量精度有了明显提升，尤其是在一定测量区域内激光面的边缘处，这可以扩大发射器的有效测量区域，并拓宽和深化光电扫描测量网络的应用领域。
