Several hundred thousand visitors are expected to descend on the town of Bad Hersfeld in eastern Hesse in just ten days for this year’s “Hessentag” festival – a Herculean feat of logistics and organization for the administration of a town with a population of 30,000. In order to cope with the influx of people, Bad Hersfeld has called upon the expertise of Topcon. With the aid of a mobile mapping system, an aerial drone and state-of-the-art software, Topcon’s infrastructure specialists produced a “digital twin” of Bad Hersfeld in just a few days. The town administration can now use this digital model to plan traffic flows, emergency access routes, and the entire event logistics of the festival period down to the smallest detail.
这town of Bad Hersfeld in eastern Hesse has plenty of experience of large-scale events. Since the 1950s, the town’s festivals have been attracting theatre-goers from across the world to this district town by the River Fulda. The last few years have seen over 100,000 visitors throng the town’s theatres during the festival weeks. But what is set to happen to the town’s 30,000 inhabitants over ten days this coming June will put all previous festival experience in the shade: Bad Hersfeld is hosting the Hessentag in 2019 and is expecting several hundred thousand visitors.
这Hessentag是德国最大的联邦州节。为了在节日期间避免在Bad Hersfeld中的交通混乱，在市长Thomas Fehling的支持下，该镇的政府呼吁一些智能解决方案。Topcon的往绩和奉献证明了Bad Hersfeld市长他们找到了合适的合作伙伴：“我们举行了联合会议，我们讨论了像Bad Mersfeld这样的小镇如何从数字双胞胎中受益。我们很快意识到我们讲了相同的语言，并且有可能在技术，行业和管理之间建造桥梁。” Fehling回忆道。该镇的“智慧城市”项目是他内心深处的项目，它明确地关注对当地居民的利益：“公民的生活质量将有所改善。”
700,000 measurements per second
部署的基础设施专家以手机映射系统和空中无人机武装的Bad Hersfeld进入。TopCon项目经理Heiko Lohre解释说：“我们创建了一个镇上的数字双胞胎。”项目经理与他的团队一起，数字化捕获了市中心，后勤路线，饲养场和可用的停车位。Lohre继续说道：“我们的城市模型再现了向Hestentag游客提供运输和物资的所有道路。”在短短六个小时的时间内，技术人员及其TopCon设备收集了Bad Hersfeld和周边地区130公里长的交通路线网络的所有必要地理。
这mobile mapping system they used, Topcon’s IP-S3, consists of an odometer, an inertial measurement unit (IMU), and a GNSS receiver, enabling it to provide even more reliable and accurate data. The mobile mapping system is mounted onto a car and captures 700,000 laser measurement points per second while the vehicle is in motion.
当车辆以每小时80公里的速度行驶时，可以捕获数据。该系统与所有通常的流量无关。“当车辆在交通信号灯处停止时，数据捕获会自动停止，”防止任何不必要的数据被捕获，强调Lohre是为了应对适用的数据保护法的问题。
然而，基础设施专家在很短的时间内收集大量数据。Lohre说：“我们的移动映射系统捕获了每小时旅行的50千兆字节的数据量。”车辆的后座是一台有四个硬盘驱动器的PC，在旅途中存储了捕获的数据。测量团队需要沿着某些路线行驶几次，因为即使是停放的HGV也可能阻止其背后的人行道正确捕获。Lohre补充说：“因此，一旦捕获的障碍消失，我们只是再次越过该点。”
Combining data from five sensors
映射旅行完成后，TopCon的专家使用原始数据来生成该镇的数字双胞胎。Lohre解释说：“模型的准确性是在办公室创建的。”总共五个不同传感器的数据被混合到均匀的点云中。除GNSS数据，激光测量点和其他车辆数据（例如设备所包含的汽车的倾斜行为）外，BAD HERSFELD模型还借鉴了摄影数据，该摄影数据也与映射系统同时捕获其他数据。TopCon总共收集了200千兆字节的原始数据，从潜在的Hestentag位置收集。
这final stage of producing the digital twin requires around four times as long as that of mobile mapping. “The key aid for doing this is our infrastructure and construction software Magnet Collage,” continues Lohre, the project manager. This single software solution allows point cloud data to be combined, visualized and analysed with a high processing speed, even if the data originate from different sources.
Bad Hersfeld独立使用其数字双胞胎
这Topcon team has given the town’s mayor a copy of the finished 3D model of Bad Hersfeld on a hard drive. “To do this, we use LAS and LAZ files, which are both common exchange formats for 3D point clouds,” explains Lohre. The further handling and planning-related use of the town’s digital twin is being managed by Bad Hersfeld itself. “But should any missing points be discovered in the model’s data set, we will return to Bad Hersfeld and use our capturing and measurement systems to correct the model,” he assures us. He notes another requirement that his team had to take into account in Bad Hersfeld. Mayor Fehling instructed the experts to ensure that the process used in Bad Hersfeld can be transferred to other municipalities and cities. “That posed no problem for us,” remarks Lohre. The working and capture processes can be repeated in other cities at any time, he says.
Aerial drone captures festival venue
Of course, the forthcoming Hessentag is not the only thing the digital model of Bad Hersfeld will be used for. When the state government of Hesse heard about the measurement project, Topcon was assigned another task. While they were capturing the town centre and the relevant traffic route network, the measuring team also took measurements of the ruins of Bad Hersfeld Abbey using an aerial drone. The approximately 900-year-old ruins are the property of the State of Hesse, and not only are they the world’s largest Romanesque church ruins, but they also form the impressive backdrop to Bad Hersfeld’s annual festivals. The model data captured and processed by Topcon can be used straight away to produce accurate plans of the festival’s 1400-square-metre main stage, located within the abbey ruins, Lohre asserts.
Initial planning benefits already realized
Bad Hersfeld已经在其最初的步骤中使用了数字双胞胎，朝着成功良好的Hessentag迈进。现在已经知道了确切的可用停车位，以及可以在市中心竖起节日看台的区域而不阻止紧急访问路线或使其太狭窄。由于数字模型，事件物流也更容易组织。市长托马斯·菲林（Thomas Fehling）对结果感到满意：“我们城镇政府的工作人员现在可以从办公室确定访客如何从A到B旅行以及允许舞台组件的大小，以便将他们交付给他们各自的活动位置没有任何问题。