问答视觉定位和Leica GS18 I
产品工程师METKA MAJERIC回答有关视觉定位技术和Leica GS18 I GNSS RTK Rover的问题。
What are the challenges when surveying with a conventional GNSS sensor?
为了能够测量点,GNSS传感器需要接收卫星信号。仅当GNSS RTK传感器具有进入开放的天空,杆尖实际上可以到达点。如果不可能,测量师可以使用替代方法,例如:
- 不同的解决方法,例如录制偏移,使用COGO功能和草图
- 与GNSS RTK传感器相结合的其他设备,例如CS20与融合的DISTO or a 4 metre pole. This way of measuring can be time-consuming and may also compromise the accuracy.
- 替代传感器,例如总站。bob apple当只有几个无法用GS传感器测量的点时,使用此类替代方案也可能很耗时。
用户面临额外的挑战,当许多细节需求调查. Measuring every single point with the pole tip requires a lot of time on site. There is also a risk that some points are missed, and the site needs to be revisited resulting in additional costs.
Leica GS18我如何克服这些挑战?
使用GS18 i,无需使用其他耗时的方法或其他设备。由于GNSS,IMU(惯性测量单元)和相机的整合,可以使用GS18 I内的视觉定位技术从图像中测量对天空和其他无法访问的点的障碍物的点。从远处捕获以测量级的精度测量。
在哪些情况下,调查专业人员会使用视觉定位技术?
视觉定位特别适合:
- 绘制数百点。
- Measuring inaccessible points such as across a busy street, behind a gate or in dangerous areas (e.g. with the risk of being attacked by a dog, hazardous utilities, on a roof edge).
图1 -Leica GS18 I GNSS RTK ROVER,同时测量栅栏上的点
- Surveying points in places with GNSS signal obstruction (e.g. under a roof, balcony or tree).
- 测量建筑物立面上的点(例如,窗户的拐角和屋顶的高度)。
Figure 2 - Measuring faCADES
- 测量其他点,而无需重新审视站点。
- Generating point clouds of captured objects.
图3-由GS18 I捕获的图像组生成的点云
- Volume calculation of stockpiles.
- 捕获碰撞场景的图像以进行点测量。
图4-捕获撞车场景
谁应该使用GS18 i?
GS18我是为需要轻松测量到具有挑战性的用户而设计的,这些要点是通过传统的GNSS RTK Rover到达。GS18 I是用户在现场收集大量数据的理想工具。用户可以稍后决定,哪些点在图像调查级准确性中进行测量。
我的GS18如何工作?(测量原理)
让我们以以下视频为例。
The following video shows how the algorithm running on the GS18 I tracks the features during capture:
The images can be used for point measurement immediately after. This is made possible by the Visual Positioning technology.
需要哪种软件来处理捕获的图像?
GS18 I在CS20 LTE或基本控制器或CS35平板电脑上运行的迷人软件得到了完全支持。
Caintivate将自动处理,定位和定向捕获的图像,从而确保现场已经在现场上进行质量控制。在使用类似技术时,无需手动匹配任何参考点或行。
如何在图像中测量点以及需要哪个软件?
从CS20 LTE或基本控制器或CS35平板电脑上的迷人运行的图像中测量点。捕获图像后,用户可以立即测量现场的点。
图像也可以进口到无穷大,用户可以在大屏幕上测量办公室中的点。
Simply pick one point in an image and the algorithm will automatically match the same point in the other images. With one click the 3D coordinates of the measured point will be calculated and stored within Captivate, just as they would have been with the pole tip.
图5-前方的交叉点
What is the fundamental principle behind Visual Positioning technology?
视觉定位技术基于GNSS位置,IMU和捕获的图像提供的信息。
让我们以以下视频为例,以衡量原则为例。
To measure points with a GS18 I, go to the start position and begin capturing images in Captivate. Now walk along, holding the GS18 I with its camera facing the corner. Images will be automatically captured with a frequency of 2 Hz. After the capturing is stopped, Captivate automatically computes the position and the orientation of the images in a global coordinate system, by integrating the data from the GNSS and the IMU with features recognised in the images. These images are then saved as an image group within Captivate.
图像是实时处理的,可在捕获停止后立即用于测量点。仅使用一个图像,可以单击一次点数。在Captivate上运行的算法将自动匹配其他图像中的挑选点,并通过正向交叉路口计算局部坐标系中点的坐标。
Is it also possible to create point clouds from captured images?
我与GS18 t有何不同?
我为什么要投资于Leica GS18 i?
这就是为什么我可以对用户受益的GS18的原因:
- GS18我是一个多才多艺的GNSS RTK sensor. It can be used to measure points with a levelled or tilted pole. In addition, it can be used to measure inaccessible points with调查等级的准确性通过捕获和测量图像。
- Inaccessible points can be easily captured in images without compromising安全。无需担心如何在繁忙的街道上测量点数或与危险的狗的财产。
- 通过有效捕获场景并稍后决定,减少现场时间。这会提高生产率,因为您可以测量现场或办公室中图像的点,也无需返回站点即可测量新的点。
使用GS18 i时,用户应该考虑什么?
Visual Positioning technology is based on the GNSS and IMU measurements as well as the images captured with the integrated camera. There are some conditions that should be considered, when using the GS18 I for measuring from images:
- GS18我需要在测量过程中足够接收GNSS信号。如果丢失了GNSS卫星的跟踪,则捕获将自动停止。
- 如果需要视觉定位,请避免在黑暗的条件下或直接面对太阳时使用它,因为捕获的图像中的足够特征将不容易识别以匹配它们。
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为了获得最佳的准确性和性能,请从2m至10m之间捕获感兴趣的对象。
当图像从低于2 m的距离捕获时,由于相机的固定焦点,图像可以模糊。另一方面,当图像从大于10 m的距离捕获时,精度会降低。
It is possible to capture images from a distance less than 2 m or greater than 10 m from the object. In such cases, the user has to take into consideration, that the accuracy may be reduced. There is also a risk that measuring points using images will not be possible.
- Image capture speed is optimised for normal walking speed. It is not possible to use the GS18 I mounted on a moving vehicle because the images might be blurred.
METKA MAJERIC
产品工程师
Leica Geosystems
To learn more about theLeica GS18 i, please visit:www.sendai-torema.com/gs18i