When electricity is on the line

Providing electricity to a whole country is a demanding task. It gets even more demanding when roughly one-third of the country is covered with woods and the other two-thirds contain Europe’s highest summits, the Alps.

To provide undisturbed supply and keep the electricity streaming, the Alpiq EnerTrans AG integrated Leica Geosystems Unmanned Aerial Vehicle (UAV) solutions into their workflow to manage visual inspections of the powerlines, their insulators and their poles. Evolving the use of an UAV to improve workflows, Alpiq EnerTrans AG took it to the next level, creating an innovative way for vegetation management, monitoring the environment threatening aerial cables using Leica Geosystems hexacopter.

Vegetation management from the air

Regular monitoring of the environment around infrastructural constructions is the first step in vegetation management. These structures include:

• 电力线路
• Pipelines
• Railways

下一步是计划和进行维护工作，以防止任何事件。因此，需要在周围的植物区与线之间的最小距离。这在航空电力线方面非常重要。由于绝缘层太重，线周围的空气可作为无导向的保护。为了防止任何短路，彼此之间的线条或任何植被都不应比最小距离更近。

Earth faults and short circuits can cause heavy damage, fire and even lead to the teardown of a line, which could mean a power blackout for thousands of people. The minimum gap depends on the national laws, the operating voltage and a customised offset given by the company.

In the past, Alpiq EnerTrans AG was using experts to walk next to the powerlines to estimate the space between the conductions and the vegetation, to see if anything would interfere with the minimum gap. In doubt, the whole segment of the conduction had to be shut down and the crew had to climb up to get a more detailed view.

Neither was this method very accurate, mainly because it was based on appraisals, nor was it very efficient. With most of the constructions being built in difficult terrain, the inspections were very time consuming and it was a major effort for the crew to inspect the powerlines through the rough terrain. Apart from this method, Alpiq EnerTrans AG monitored its grid by using helicopters with infrared-, korona-, RGB-cameras, as well as laser scanners, to get ahead of possible threats caused by the environment

Alpiq was looking for new ways for their vegetation management and found their perfect match in an UAV based solution to:

• Raise efficiency
• Heighten safety
• Increase precision

使用无人机来获取与小型船员和轻型设备相结合提供的直升机的详细信息，是多功能性和颗粒状的完美结合。为了捕获与分析有关的所有数据，Sony Alpha 7R具有其全帧CMOS传感器（36.4megapixel），并将28毫米镜头安装在无人机的阳性上。

The first step in using an UAV to monitor the environment surrounding the powerlines is to prepare the flight plan. Every segment to be monitored later has to be surveyed before the flight to get a detailed view of the states and possible danger spots. This becomes important when the crew is planning the most efficient waypoint flight in the next step.

内部构建的飞行计划软件计算了无人机的最有效路线，地面采样距离（GSD）和高度，向您显示了整个操作的持续时间和路点。完成这项任务的另一种方法，尤其是在该区域难以预测的情况下，是在功能上的教学，在这里，无人机从飞行中保存了航路点，以便下次在这个地方记住它们。

To increase the precision, the a RTK/GNSS module can be attached and references the UAV with a scope of 1-3cm. This method is based on the technology of NovaTel and Leica Geosystems.

驱逐开销线路后，数据的进一步处理开始。在特殊软件中使用无人机日志文件的GPS数据进行录制的图像。通过搜索的数据，创建了该区域和环境的准确3D点云。

In the next step, data of the position and the height of the poles are added and the models gets referenced through the GPS coordinates of the poles. After the model is set, computed conductions are added, to simulate the maximum conductor coil sag.

In the further process, the calculated point cloud is given to the Swiss company picterra GmbH. The software determines the distances between vegetation and power lines. Those points are marked in the point cloud at which the minimum distance is determined. A situation plan is derived from the model that shows the hazards as well as the parcel boundaries and numbers, roads, paths, lines and mast designations. On the basis of the situation plan, the coordinates of the hazard points can be clearly located.

Finding the right gap

通过使用Leica Geosystems无人机解决方案，Alpiq现在能够准确地确定高架线和周围植被之间的距离as much as ± 30cmin order to ensure a smooth operation of their routes. Since the current paths must frequently be checked at irregular intervals, the full potential of the UAV develops, in this case, in order to generate exact and comparable results from partial sections.

The entire monitoring can now be carried out by a small crew, since only one other person is required to watch HD live transmission on the screen. The cost advantage compared to a helicopter and the associated crew as well as the elaborate sensors is obvious. Another advantage of using an UAV is the possibility to generate precise data again and again in order not only to create snapshots but to generate a longitudinal section for a long-term study from the data obtained.

Leica Geosystems UAV as a floating multisensor platform also offers the possibility to use other measuring methods. So, Alpiq EnerTrans AG is extending the workflow to a multispectral camera, such as the Parrot Sequoia, to determine the Normalised Differenced Vegetation Index (NDVI) of the vegetation. This can identify regions that need to be inspected more frequently due to increased plant growth. This operation消除了对昂贵和大规模检查的需求with helicopters, as areas where the overhead lines are threatened by vegetation can be predicted precisely.

The UAV is also equipped with a LiDAR sensor to achieve even more precise results. By using a LiDAR sensor, the UAV can generate毫米精确点云from the air and thus work even more precisely.

使用无人机收集数据管理数据的优势不仅是降低成本和增加的安全性。相反，基于无人机的开放线监视是一种多重灵活性，可以选择性且高度精确的植被管理。在现场检查或使用直升机的情况下，仅收集瞬时记录。该工作流与无人机生成数据，可以从中模拟和分析各种方案。这使得不仅可以确定实际情况，还可以进行详细的预测。

"The aerial robot from Leica Geosystems supports Alpiq EnerTrans AG optimally in the fulfillment of our demanding inspection tasks. A device for professionals by professionals!" - Rudolf Meier, chief executive of Alpiq EnerTrans AG

通过Alpiq Enertrans AG的创新方法，通过使用Leica Geosystems UAV来指定和现代化植被管理，该公司不仅可以更有效地工作，而且还可以依靠可靠的数据来抵消任何故障。