旋风场360提高了现场的生产力

自2018年推出以来Leica Cyclone Field 360是市场上唯一可以执行预注册程序和点云对齐的移动设备应用程序之一，并结合高性能Leica RTC3603D laser scanner andLeica BLK360imaging laser scanner.

在引入Cyclone Field 360之前，在使用陆地激光扫描仪时，互相注册点云提出了一个关键挑战。市场上有一些解决方案在现场提供了注册，但是由于数据传输时间，计算时间和高规格硬件要求，数据采集放慢了速度，这阻碍了该领域的生产力。Cyclone Field 360与轻量级预览对象（LWPO）技术相结合，不仅可以在几秒钟内进行预注册，还允许客户使用自己的Android或iOS移动设备，例如智能手机或平板计算机。

Let’s take a look at the key functionalities that make this ground-breaking technology possible:

Lightweight Preview Object (LWPO)
The LWPO technology within Cyclone FIELD 360 enables a visual representation of the captured scan data, using only a fraction of the actual scanned points. The data size is therefore dramatically decreased as well as the data transfer time between the laser scanner and mobile device. It provides instant visualisation of the captured scan data on your chosen mobile device which allows you to check and inspect the data for completeness. It is important to know that using LWPO in Cyclone FIELD is fundamental for enabling complicated operations, such as automatic point cloud alignment to be done with minimal time and resources on mobile consumer end devices such as smartphones or tablets.

3D View
Enabling customers to use their own mobile devices does come with its challenges. One challenge is managing different devices with limited capabilities while displaying and navigating large point clouds in 3D. This is made possible in part by limiting the total number of displayed points on the screen so data visualisation is still optimally performing. If a bundle consisting of multiple setups is displayed, the point cloud can appear to be more sparse than if only a single setup is displayed. Another strategy to manage the mobile devices capabilities is to link point cloud density to viewpoint distance. If the viewpoint is far away from the point cloud, a relatively small amount of points can represent the scanned area in sufficient detail. If on the other hand the user zooms in on a small area of the point cloud, more points are displayed to make sure every detail is visible. These two methods work simultaneously in the background without any user interaction needed to ensure a smooth and responsive experience when viewing and navigating point clouds in 3D.

Pre-registration
Cyclone Field 360的一个核心功能是将下采样的扫描数据直接在现场中彼此进行。预注册产生的相对扫描位置有助于减少办公室完整数据集的最终注册工作。为了在现场最大的效率，预注册时间不能超过扫描时间，以确保在现场中的数据采集不会放慢速度（扫描仪时用户准备就绪）。

此预注册时间由两个因素最小化：

• Small calculation times (algorithms are optimised for LWPO data)
• 使用最小用户输入的简化工作流程

The combination of these factors is what makes pre-registration of LWPOs in the field effortless and easy with Cyclone FIELD 360. Especially for BLK360 and RTC360 LT, the pre-align feature plays a key role with regards to both of the above mentioned factors.

Pre-align feature for BLK360
Cyclone Field 360于2018年首次使用RTC360 3D激光扫描仪发布，自2019年5月以来，它也支持BLK360。而RTC360基于视觉惯性系统（VIS）技术, the BLK360 does not have this feature so information about the relative setup positions is not available to start with. This means that before optimising the scan positions and creating a link, users would have to manually align the setups to each other in the field. Depending on the complexity of the environment, this manual alignment process takes time and can be prone to human errors.

To mitigate these risks and speed up the workflow, the pre-align feature was introduced with version 2.1 of Cyclone FIELD 360. Pre-align is a feature within Cyclone FIELD 360 which automatically aligns two scans (that share overlap) without any information about their approximate relative positions. In order to align the scans, at least three identical points in the overlapping areas must be known in both point clouds. Pre-align picks up to 3,000 points in both point clouds and matches points with similar geometric properties using clever algorithms.

Visualised matches (pink lines, 700 out of 3000) between points with similar geometric properties in two point clouds that share overlap: in arbitrary orientation and translation on the left, in correct orientation but incorrect translation in the middle and aligned to each other on the right.

All that’s left to do for the user in the field is to optimise the relative scan positions and create the link. The time taken for these three operations does depend on the mobile device used, however for powerful devices (e.g. iPad Pro 2018 with 4GB of RAM and Apple A12x Bionic chipset), pre-aligning two scans is achieved in less than three seconds and optimising their pre-aligned positions takes less than one second. Including the time to verify the results and create the link, it is fair to say that pre-registration of two LWPOs in the field can be completed in under five seconds!

Peace of mind
Using Cyclone FIELD 360 not only allows the user to inspect the captured scan data directly in the field, it also provides confidence that the final registration in the office will check out (enough overlap) and it speeds up the entire registration process by delivering approximate setup positions that can be utilised by the office software. Customers can potentially leverage all of these benefits without additional hardware costs or super-powerful computers in the field by simply downloading the free app on their Android or iOS smartphone or tablet computer.

Cyclone FIELD 360 is integral to our overall laser scanning workflow and continuous improvements are done to embed customer feedback and to further improve system productivity.

Cyclone Field 360移动设备应用程序免费下载。需要有效的旋风寄存器或旋风寄存器360许可才能激活Cyclone Field 360。

从The下载Cyclone Field 360应用App StoreandGoogle Play.

For more information, please contact your local Leica Geosystems sales representative.

雅各布·利德尔（Jakob Lidl）
Senior Product Engineer, Terrestrial Laser Scanning
Reality Capture Division