Intergeo 2013 Essen. Germany Laser scanning

    Hello, dear Habrasociety.

    The event, about some aspects of which I would like to tell you, can be attributed to a very widely known in narrow circles. Let me say a few words about what Intergeo is .

    This is an exhibition of the achievements of the geodesic-cartographic economy, which has been annually presented in Germany for more than 20 years. There is simply no larger event that would affect such areas as geodesy, cartography, photogrammetry, GIS and spatial modeling. There are major leadership workshops, but they are usually based around the same brand (e.g. ESRI).

    That is why at Intergeo you can evaluate the current development of many areas, see the latest developments, find direct contacts with manufacturers. The participation of the company in this exhibition can be directly assessed as its positioning on the world market.
    image

    Initially, I planned to do a post-review of all the areas presented at the exhibition, but after analyzing the materials collected at the exhibition, I realized that for this I would need several weeks, I now have such diverse information. Therefore, in this post we will talk only about one, young and promising direction, which has recently gained such momentum that it is impossible not to pay attention to it. I propose to discuss the current state of laser scanning (with a slight bias in 3D modeling).

    Separately, I want to indicate that the following aspects of the exhibition interested me primarily as a surveyor engineer.

    Let's start with a short digression into history, albeit a short one. The development of digital geodetic technology, in particular laser rangefinders, predictably led to the first attempts to assemble a laser scanner. The first mention of such devices dates back to the mid-90s. So, for example, Cyberware released in 1991 a device that can scan small objects; these scanners were supposed to be used in medicine. For geodesy, these devices were not suitable, but the principles have already been defined.

    The first geodetic scanners appeared under the brand Cyrax model 2400 in 1998, at about the same time the RIEGL Scanner LMS Z 210 came out. Three years later, Cyrax was bought by Leica, while Riegl still exists on the market as an independent manufacturer.

    In a few words I will describe what the laser scanner does and why it is needed. At its core, a scanner, like a total station, is a goniometer with a laser range finder. The only difference is that the scanner performs a very large number of measurements per unit time, rotating the measurement plane around its axis. Thus, scanning the space around him.

    image
    Trimble GX laser scanner in front of the scanned building. Taken from Navgek Engineering

    At the output, we have a “scan” - a point cloud that is characterized by low discreteness, and under certain conditions it can be perceived as continuum. Why is this necessary. If we have an object of complex shape (for example, an industrial installation, or the facade of a historical building, etc.), then it is very difficult to reproduce its mathematically accurate image by traditional geodetic means. A scanner is faster and easier (but not always).

    image
    Point cloud. Taken from Navgek Engineering

    From the very beginning, laser scanning competed with photogrammetric shooting, which allows you to do almost the same, but subject to a sufficient number of additional conditions. But it is cheaper. It was in any case. While scanning wins.

    What is usually scanned? Architecture - especially old facades, industrial enterprises with a bunch of pipes, passages, etc., volumes - tanks, plugs, interior. In land surveying and cable laying, scanners are rather useless.

    Naturally, such technology did not pass by active players. All leaders of the geodetic market zealously took up the development (or purchase) of technology. At the moment, only Javad has not boasted of its scanning solution (because it is completely focused on GPS). Leica, Trimble, Topcon produce scanners. Along with them are Z + F, Riegl, Faro - specialized manufacturers of exclusively scanners. Once, even UOMZ intended to release a scanner and even sawed a prototype from plywood, but somehow it didn’t work out further. Mention is on the omniscient "surveyor". Although the Russian Surphaser scanner exists.

    At this stage, the following segments can be distinguished in laser scanning: ground-based laser scanning and mobile laser scanning.

    As for the ground part - this is the main niche of laser scanners. The main competition is for technical specifications - who is farther, denser and more accurate can create a point cloud. Well and faster, of course. Everyone is participating in the competition. Another tendency is to reduce the size of the scanner, here is the leader of Faro, whose scanner is no larger than a toaster in size.

    The latest trend is to integrate a controller screen into the scanner body itself, from which control operations can be conducted. The monitor is small, but now the scanner management software from the laptop can be sold separately (Leica and their Cyclone example). Leica P20, Trimble TX5, TopCon already have such scanners. The latter, however, presented at the exhibition a scanner for which there is no information at all, no model. And attempts with the help of an internal controller to create a scan zone were thwarted by the manager with the wording "this function is in the scanner, but there are no menu items for it."

    image
    Z + F scanner with controller side screen.

    Consider the Leica P20 scanner as the most typical representative of the segment. The range is 120 meters (quite a lot for a phase scanner), accuracy 3 mm per 50 m, 6 mm per 100 m. Able to scan with a resolution of 0.8 mm at a distance of 10 m, while the scan time will take about 1.5 hours. Weighs 12 kg, dimensions 24 * 35 * 40 cm.

    image
    Leica P20 scanner. Image taken from here.

    For these devices, there is another parameter that, unfortunately, cannot be objectively assessed - this is exposure to the influence of the external environment. None of the manufacturers provides statistics on equipment breakdowns. And in other cases, this is the main determining criterion. Often, companies actively engaged in laser scanning work immediately acquire 2 scanners, realizing that after the first projects one of them will go to the service. In addition to word of mouth, it is impossible to determine the viability of a particular model. Leica P20, according to random opinions, is “tenacious”. The manufacturer assigned it a class of IP54 and a temperature mode of operation from -20 to +50. 5 years ago, such parameters were a fairy tale, and in winter scanners put on covers with thermochemical heating elements.

    A surprise in this segment was the outwardly modest Hi-Target scanner. It is unremarkable, except that it is the first independent Chinese scanner. How it works is a big question. But this is the first swallow from Asian friends, so they try themselves in a geodesic Hi-End. As for the Low-End, inevitably after the exhibition the impression is created that the laziest Chinese have not yet soldered a two-system GPS geodetic receiver and have not assembled a digital total station. It was the turn of the scanners.

    image
    The first Chinese Hi-Target scanner.

    Mobile laser scanning is a trend of recent years. Similar solutions have been met before, but perhaps only this exhibition showed that all the leaders of the geodetic market rushed into this niche.

    Each of the leaders demonstrated similar systems on different media. Leica, Trimble, Topcon, Riegl, Faro placed laser scanners on cars. The devices are very similar in parameters, so let's turn to the Trimble MX2 mobile laser scanner, presented on the roof of the Mini.

    image
    Mini Roof Trimble MX2 Scanner

    Of course, the first thing that interests you is accuracy. This device claims 10 mm at 50 meters. This accuracy is achieved due to the installed inertial system, coupled with 2 satellite dishes, the accuracy of which during post-processing is declared in the range from 2 to 5 mm. Visibility 360 degrees. Range of 250 m, but most likely at such a distance the accuracy will drop to 5 cm.

    The second thing that interests you is at what speed can I scan? Trimble doesn’t have this information directly, so you have to turn to Leica data with their HDS7000 scanner mounted in the Pegasus: One photo system. Most likely, you will have to limit yourself to 40 km / h. According to representatives at the stand, the speed can be maintained even faster (for example, when shooting freeways), but then the cloud turns out to be rarefied, and the exit can be found in the scanner’s repeated passage along the highway.

    image
    HDS700 Leica Scanner

    Probably worth mentioning the cost of these devices. A laser scanner is far from a cheap tool and when buying a similar ground-based device, you should rely on a price starting from 80,000 Euros. As for the mobile solution, when you buy "all inclusive" the price of the issue increases by about 4-5 times. Nobody will clearly tell the exact price in Russia for new devices, only an approximate order.

    Separately, I want to note 2 derived solutions. The first is the Faro scanner (the one with the size of the toaster) mounted in a quadrocopter.

    image
    Flying Scanner Faro

    The manufacturer positions it as the ideal solution for architectural photography, with an accuracy of 10 mm. The bottom line is that first the points determining the contours of the building are removed by the total station, and then the route along which the scanner makes a fly is laid in the quadrocopter controller. What is fundamentally better than ground-based shooting - guaranteed coverage of dead zones. From the ground, a big problem is to remove the roof and the upper elements of architectural details. In practice, often, these details are extrapolated, and the objectivity of reflection is in question.

    Why this solution is worse - it is less accurate (a ground-based scanner can provide 2-3 mm accuracy), and also so far unprotected. To my question - what kind of protection is this scanner from water and dust, the representative answered modestly that there is none. Recalling my personal experience in scanning metallurgical plants, where metal dust hangs in the light of air, I can say that this device flies, most likely, not for long.

    image
    Riegl shipboard scanner

    The second solution is the Riegl VMS-250 scanner. There is no information on it yet in the network, but it is expected that its characteristics are similar to other mobile scanners. This company went further in positioning the scanner and offers to place it not only on cars, but also on trains (they even completed a pilot project between St. Petersburg and Moscow), as well as on small boats. The global idea is that many surface structures (bridges, platforms, moorings) are incredibly difficult to remove (or simply impossible) with a ground scanner, but approaching on a yacht with a scanner is a well-grounded decision.

    Theoretically, the two solutions above could compete. Those. one could choose to fly up to the structure or swim. But Faro's solution is still unfinished, while Riegl is ready to supply this system, including to the Russian market.

    It should be noted that in addition to these two segments on the market there were two more areas of scanning - manual model, i.e. the device can scan a person and lidar from the side of a helicopter (a very old direction that began even before ground-based scanners). For certain reasons, I did not pay much attention to them (the first is not applicable to geodesy, the second is already quite understandable - low accuracy and problems with vegetation, at the same time, the enormous cost and complexity of organizing in the Russian Federation).

    image
    Manual scan of a person. Presentation.

    Scanning problems lie not only in the laser scanners themselves, but also in the processing of the resulting material. Usually, the technological process looks like this:

    Scanning - Scanning stitching - modeling in the scanner manufacturer's software - exporting to CAD - model finalization - receiving model drawings - drawing design.

    At each of the above stages, solutions are applied that are far from ideal. It does not make sense to list all the problems, but at each stage the software is brought to mind.

    Leica Cyclone allows stitching of scans not only by spheres (in order to connect adjacent scans, standardized balls are hung on the object, their recognition by software allows you to reduce a cloud of points), but also by structural elements (for example, pipe bends, ends of metal structures - channels), assigning them the role of the spheres.

    Cubit software allows you to exclude the simulation phase in the manufacturer’s software, allowing you to enter point clouds directly into CAD.

    Special attention is paid to modeling standard structures, most manufacturers have come to the conclusion that standard objects can be created (for example, according to GOST there is a 1220 mm pipe - this is the diameter of the pipe selected from the catalog), and they will be automatically entered into the clouds.

    What conclusions can be made. Laser scanning has already survived the stage of the first experiments and took shape in a separate direction of geodetic surveys. Development is still ongoing, but if the ground segment has already taken shape, then mobile laser scanning is still in its infancy. Simulation is becoming more convenient and faster, which means that scanning technology will gradually become cheaper due to man-hours, which is extremely important, since the cameral stage in this industry can reach 80% of the duration of the entire project.

    In Russia, laser scanning is also developing. According to managers of various companies, the number of such devices that work with us has long exceeded the first hundred. For foreign companies, which they clearly recognize, Russia is one of the main markets for these devices. Construction, reconstruction, research - everywhere you can find a laser scanner.

    Also popular now: