The use of mobile scanning continues to expand due to valuable benefits such as improved safety and faster data collection. Mobile scanning devices may be handheld or mounted on a variety of platforms, each suitable for addressing different types of terrain and applications. Advances in scanning technology and miniaturization of the sensors have resulted in adoption by a variety of industries. Mobile scanning is being heavily influenced by SLAM (Simultaneous Localization And Mapping) technology, which provides new opportunities to operate in difficult-to-reach areas without GPS signals.
What Makes Simultaneous Localization And Mapping Technology Different
SLAM technology involves cameras and/or laser sensors continuously capturing 3D measurements and over time stitching those datasets together to generate a map without the aid of satellite positioning. The technique was first developed in the robotics industry to help robots understand their surroundings and safely navigate through an unfamiliar environment. Using statistical and mathematical algorithms, a device can simultaneously localize (locate itself in the map) and map (create a virtual map of the location) using visual data, or non-visible data sources (e.g., Sonar, Radar, LiDAR) combined with basic positional data provided by an inertial measurement unit (IMU).
UK-based company GeoSLAM is a developer of hardware and software that incorporates SLAM technology into 3D mapping solutions. GeoSLAM devices can be handheld, mounted on UAV, or mounted on a backpack frame for hands-free scanning. They integrate cameras and sensors to provide the most flexibility for any situation, whether indoors, outdoors, or underground.
“GeoSLAM has always been an innovator. We started developing custom systems for challenging technical problems in the mining industry, and have since applied our processes to infrastructure, power, traditional survey and real estate,” says Neil Slatcher, chief product officer at GeoSLAM. “We try to be very flexible with hardware and software and incorporate lots of different sensors – such as a panoramic camera with GPS support and thermal cameras. This makes our solutions different from traditional off-the-shelf products.”
GeoSLAM released the world’s first handheld SLAM-based mobile mapping system in 2013 and has continued to extend the capabilities of its SLAM algorithms. Its latest release, the ZEB Horizon, can be handheld or mounted on a UAV and has a collection rate of 300,000 points per second and positional accuracy of approximately .5–1 inch (1–3 cm). Data processing is fully automatic, so the operator doesn’t need to have a deep understanding of SLAM technology to get the desired results.
Variety of Applications for SLAM Technology
Although mobile scanning can be accomplished without SLAM, the technology offers the advantage of capturing data in areas with limited or no GPS, hard-to-reach spaces and hazardous situations. Faster collection means reduced time in harm’s way, as well as lower costs. In addition to robotics, SLAM capabilities enhance data collection for virtual reality applications, 3D modelling, surveying, volume calculations, autonomous driving and more. SLAM’s flexibility and speed attracts users who run the gamut from professional surveyors to construction workers to real estate agents.
Vehicle-mounted LiDAR systems have already proven themselves as useful tools for mobile mapping, and with SLAM, data is being collected at higher speeds than ever before, even in urban canyons without GPS. Performance at high speed is a key factor for driverless cars that are expected to recognize where they are and react to their environment in near-real time.
Acceptance of UAVs and Beyond Visual Line of Sight (BVLOS) operations is also increasing as SLAM provides improved navigation and collision avoidance capabilities. UAVs are gaining more significance in areas like inspection (pipelines, utilities, mining, etc.) and provide a different perspective for mapping over difficult terrain.
Handheld and backpack systems also offer versatility in areas inaccessible by vehicles. Even if walking across a field or through a tunnel without GPS, the SLAM device will efficiently produce a 3D map of the surroundings.
“There will always be situations that require total stations and expert surveyors to achieve the highest precision,” says Slatcher. “However, SLAM is very effective for professionals who are faced with challenging spaces, such as mines or ceiling voids, as well as non-professionals like real estate agents who need to quickly map the floor plan of a house without disturbing the owner.”
Another common application for SLAM is on construction sites for comparing as-builts against actual designs. There is limited time to take measurements and the sites can be dangerous, so fast collection of data is a major benefit. Also, facilities managers, who are usually not trained surveyors, are able to collect 3D scans of parts of buildings with SLAM to use for assessing and planning repairs and maintenance.
The mining industry employs SLAM hardware and software because of the unique challenges of working underground. Hazardous conditions require fast and accurate data collection. Tunnel construction and underground projects are complex and must be accurately planned to optimize production cycles. Above ground, 3D maps are used to calculate volumetric measurements of stockpiles.
SLAM’s safety benefits are also valuable for law enforcement and emergency response applications. Police officers, firefighters, etc., are often faced with dangerous conditions where a faster collection of data reduces the risk of injury or loss of evidence. For example, mapping a crime scene should be done quickly before the area is disturbed and accurately capturing the environment surrounding a car accident helps determine who is at fault and gets traffic flowing again as quickly as possible.
A Bright Future for Simultaneous Localization And Mapping
The broad appeal of SLAM technologies is driven by its ability to create detailed 3D maps and models while operating in a variety of environments, e.g., inside, outside, daylight, darkness. The SLAM devices are simpler to use than traditional surveying equipment, making the technology more accessible to less experienced operators, and the user has options including vehicle-mounted, handheld, backpacks, and UAV.
“The biggest trend happening right now with SLAM is that it’s becoming a commodity,” says Slatcher. “Demand is being driven by the rapidly expanding autonomous car industry, which is bringing prices down significantly. GeoSLAM’s approach to solving problems is our differentiator so strong interest in the technology continues to create new opportunities for us.”