成像激光雷达标定系统中三维升降转台的性能研究
Experimental Study on Performance of a Three-dimensional Rotating and Lifting Platform in an Imaging-lidar Calibration System
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摘要: 三维升降转台是高海拔宇宙线观测站(Large High Altitude Air Shower Observatory, LHAASO)广角切伦科夫望远镜阵列(Wide Field of View Cherenkov Telescope Array, WFCTA)成像激光雷达标定系统的核心组成部分,主要由慢控子系统(Programmable Logic Controller, PLC)、机械子系统和标准零点子系统构成,用于精确控制激光束的出射方向。采用高精度数字图像处理技术对三维升降转台的性能进行研究,结果表明,旋转和升降定位精度分别为0.005°和0.056 mm,重复精度分别为0.003°和0.075 mm,满足成像激光雷达标定系统的实验要求。三维升降转台的自动控制巡航功能有效减少了人工干预,提高了系统远程使用的可靠性和效率。标准零点的校准功能可以有效监测三维升降转台的定位精度,并且在失准的情况下能够实现远程校准,确保三维升降转台长期高精度稳定运行。Abstract: The three-dimensional (3D) Rotating and Lifting Platform (RLP) is the core component of imaging-lidar calibration system for Wide Field of View Cherenkov Telescope Array (WFCTA) of the Large High Altitude Air Shower Observatory (LHAASO). RLP mainly consists of three parts:the Programmable Logic Controller (PLC), the mechanical, and the standard zero subsystems, is designed to precisely control the beam pointing of the imaging-lidar system. A high-precision digital image processing method is adopted to investigate the performance of RLP. Our results reveal the rotating and lifting positional accuracies are 0.005° and 0.056 mm, respectively, while the corresponding repeatabilities are 0.003° and 0.075 mm, respectively. These outcomes fulfil the experimental requirements for the calibration system. The automatic cruise function of RLP not only minimizes the manual intervention but also improves both the reliability and efficiency for a remote control. The standard zero calibration function enables an effective observation of RLP's positional accuracy and implements a remote calibration in the case of a misalignment. As a result, we accomplish an accurately stable operation for our calibration system over a long period of time.