Abstract
Open-path Tunable Diode Laser Absorption Spectroscopy offers an effective method for measuring, mapping, and monitoring gas concentrations, such as leaking CO2 or methane. Compared to spatial sampling of gas distributions using in-situ sensors, open-path sensors in combination with gas tomography algorithms can cover large outdoor environments faster in a non-invasive way. However, the requirement of a dedicated reflection surface for the open-path laser makes automating the spatial sampling process challenging. This publication presents a robotic system for collecting open-path measurements, making use of a sensor mounted on a ground-based pan-tilt unit and a small drone carrying a reflector. By means of a zoom camera, the ground unit visually tracks red LED markers mounted on the drone and aligns the sensor's laser beam with the reflector. Incorporating GNSS position information provided by the drone's flight controller further improves the tracking approach. Outdoor experiments validated the system's performance, demonstrating successful autonomous tracking and valid CO2 measurements at distances up to 60 meters. Furthermore, the system successfully measured a CO2 plume without interference from the drone's propulsion system, demonstrating its superiority compared to flying in-situ sensors.
Abstract (translated)
开放式路径可调二极管激光吸收光谱法提供了一种有效的方法，用于测量、绘制和监测气体浓度，例如泄漏的二氧化碳或甲烷。与使用原位传感器的空间采样相比，结合气体层析算法的开放式路径传感器能够以非侵入性方式更快地覆盖大型户外环境。然而，开放路径激光器需要专用的反射面，这使得空间采样的自动化过程具有挑战性。 本文介绍了一种用于收集开放路径测量数据的机器人系统，该系统利用安装在地面水平旋转装置上的传感器和携带反射镜的小型无人机组成。通过配备变焦相机，地面单元可以视觉追踪固定在无人机上的红色LED标记，并将传感器的激光束对准反射镜。进一步结合由无人机飞行控制器提供的GNSS位置信息，提高了跟踪方法的效果。 户外实验验证了该系统的性能，在长达60米的距离内实现了成功的自主跟踪和有效的二氧化碳测量结果。此外，该系统还成功地在没有受到无人机推进系统干扰的情况下测定了一个二氧化碳羽流的存在，这证明了其相对于飞行原位传感器的优势。
URL
https://arxiv.org/abs/2602.20768
