Digitising an urban construction site

Karlsruhe每年有30万居民，城市主要地区有16万辆汽车和1.9亿辆乘客，在德国西南部的运输规划中起着决定性的作用。A5高速公路不仅会影响大卡尔斯鲁厄地区的规划场景，还影响了州街B10的城市内使用。这是该地区最重要的市中心东西方连接。卡尔斯鲁厄市以及联邦政府巴登·伍滕伯格（Baden-Wuerttembg）州通过启动两个非凡的隧道项目来对交通和整个地区的发展做出反应，以通过“合并解决方案”来缓解地面交通。

诸如“组合解决方案”之类的项目不仅没有支持者。建筑噪音，日常生活的破坏，成本，污染和环境限制只是在从事此类大规模城市项目时必须考虑的潜在问题的一部分。Karlsruhe市和Karlsruhe铁路基础设施协会（Kasig）作为建筑商为此目的开展了长期且非常早的信息运动。这是以项目网站的形式进行的，还通过公共活动和信息中心进行。建筑商以及参与的建筑公司和财团的目的也充分利用了数字解决方案在建筑工地文档中的可能性。Leica Geosystems的测量解决方案由KarlsruheIngenieurbüroGeo GmbH使用是该数字文档的决定性因素。

Highest accuracy from day one

The construction companies Ed. Züblin and Schleith are responsible for the construction of the Kriegsstrassentunnel next to the Ettlinger Tor. Combined with the second tunnel in Kaiserstrasse, both construction projects are "The Combined Solution" for the City of Karlsruhe, which will help to significantly alter the traffic situation in the inner city from 2020 and 2021 respectively. In the Kriegsstrasse, this means that the vehicles are brought under the earth, while trams, pedestrians and all bicycles move above ground. On a path of 1,600 meters, the road tunnel dramatically changes the cityscape - as well as during the construction work. The construction planning and subsequent construction supervision is also given special importance for this reason. The objective of the construction supervision cooperation, consisting of DB Engineering & Consulting, Emch+Berger and BUNG, is to get the highest accuracy in surveying, preservation of evidence and monitoring. Before working on new construction sections, the task was the initial surveying of the construction area as well as an area of 50 meters in all side streets. The expected accuracy of the data was 2 cm. This task was taken over by the team of IngenieurTeam GEO, using the Leica Geosystems Unmanned Aerial Vehicle (UAV). Equipped with the RTK and GNSS module, this technology allows airborne data to be collected parallel to the on-site operation, delivering highly accurate data by combining the UAV and the Sony Alpha 6000 with a 20mm lens.

在市中心飞行时的特殊挑战

Around the project, the Federal Court of Justice and the Karlsruhe State Theater are critical buildings. As is customary in the case of tunneling construction site, it must be ensured that the construction does not lead to unplanned changes in the environment. Any reductions or unwanted volume changes must be excluded. This exclusion has to be documented and monitored. Conventional methods can only be used to a limited extent in parallel to construction measures for security and time reasons. The use of an UAV was then recognised as an optimal solution for data capturing in the sense of an efficiency-oriented project process. The advantages of the 3D measurement and the monitoring compared to a purely point-based data acquisition using terrestrial methods lie in particular in the various usage scenarios of the generated data. They can not only answer questions from a surveying engineer's point of view, they can also be used as a basis for the planning of the traffic routes during construction work. They can be used in pro- and retrospective construction planning and are a decisive factor in volume calculation almost in real time.

使用无人机的优点一方面是在市中心飞行的挑战。因此，必须在自动化飞行计划中考虑到城市的狭窄，因此必须专门定义飞行路线和高度规划。由于现有的基础设施和开发而导致的起重机，植被和可能的磁场干扰对飞行的潜在干扰起作用。因此，本杰明·布斯（Benjamin Busse）是在Ingenieurteam Geo使用测量无人机领域的经验丰富的专家，因此在计划阶段特别强调了所有利益相关者的参与。

“The new drone regulations in Germany do not allow flights over federal streets,”says Busse. “Thanks to a good relationship with all stakeholders we got the special permission for the inner-city flights over the B10 with traffic, pedestrians and tram.”

The advantages of using UAVs are on the one hand side, the challenges of flying in the city centre are on the other hand side. Thus the narrowness of the city has to be taken into account already in the planning of the automated flight, and, therefore, the flight route and altitude planning has to be defined specifically. Potential disturbances of the flight by cranes, vegetation and possible magnetic field disturbances due to the existing infrastructure and development play a role. Benjamin Busse, an experienced expert in the field of the use of surveying drones at IngenieurTeam GEO, has therefore placed special emphasis on the involvement of all stakeholders during the planning phase.

“The new drone regulations in Germany do not allow flights over federal streets,” says Busse. “Thanks to a good relationship with all stakeholders, we got the special permission for the inner-city flights over the B10 with traffic, pedestrians and tram.”

Digital results and economic benefits

Apart from classical orthophotos, the customers also expected high-resolution single images for documentation, digital elevation models and point clouds. At the same time, the inspection of traffic route planning was mandated. This took place on the basis of existing plans, which were combined with the information from the orthophotos. As a result of the very good data from the flights and the high information quality, it is now planned to carry out quarterly monitoring, critical volume calculations as well as a supplement to the construction site diary through videos and photos from the bird's perspective with the help of UAV solutions.

The reasons for this decision are summarised quickly: using conventional measurement and surveying methods, not only significantly less data could be collected, a team of five people would have needed six weeks to deliver the desired results. The team of two people for the UAV workflow, only needed seven days. Conventionally, Leica Geosystems total stations would be used. The costs for the client using the conventional method would have been 180 per cent higher than working with the UAV solution. The monetary perspective is even more attractive from the UAV operator’s point of view: the costs for IngenieurTeam GEO using the UAV solution were only one-fifth of the costs of conventional methods.

“我们认为无人机技术是我们工具箱的一部分,” adds Martin Schwall, co-founder and managing director with IngenieurTeam GEO. “From a customer’s point of view, UAVs allow fast and digital results with many advantages for additional information.”

Digital workflows offer many advantages

Leica GeoSystems的无人机解决方案的使用提供了许多优势。与建筑项目相关的过程的数字化始终取决于高数据质量和密度。例如，UAV航班中的信息不仅可以用于计划和监视，还可以用于机器控制和项目通信任务。在进一步的开发步骤中，无人机的数据也将无缝集成到莉卡地理系统的软件解决方案中。结果不仅更快，而且可以量身定制以满足个人要求。尽管常规方法生成选择性数据，但它们不会捕获图像数据，因此不允许数字可视化。使用基于无人机，相应的传感器技术（此处高分辨率RGB摄像机）和用于后处理和数据处理的合适软件的数字端到端解决方案提供了真正的好处。除图像外，这主要是3D测量信息，基于图像数据的并行检查的选项，与日常业务平行捕获的数据以及对本地工作的测量工程师和无人机的更高安全性操作员。生成的数据是回答现有问题和将来的问题的基础，并将有助于存档从第一天开始所有施工的进展。

“As a next step, Leica Geosystems will fully integrate the UAV solutions in the software solutions for construction, monitoring and surveying”, says Valentin Fuchs, Leica Geosystems UAV product manager. “Helping our customers to visualise information and to use the collected UAV data to automate and speed-up processes is part of the bigger picture of future developments.”