Reviewed by Lexie CornerJan 3 2025
Robots equipped with cameras are commonly used to investigate unfamiliar terrain, buildings, and danger zones. In the 3D-InAus project, researchers from the Fraunhofer Institute for Communication, Information Processing, and Ergonomics FKIE have taken this a step further by using a LiDAR laser on a mobile robot to measure distances and create geometrically accurate 3D models of environments.
The LiDAR laser is attached to a rotating turntable. The laser scans an area of 16 vertical sections, or “slices,” per second. In total, the device emits 1.3 million laser pulses per second. This data is then used to produce a 3D point cloud of the environment. Image Credit: Fraunhofer FKIE
In the event of a disaster, such as a chemical plant incident or flooding, emergency personnel require immediate access to a situational assessment. However, in many cases, they cannot enter the scene to avoid putting themselves in danger.
Fraunhofer FKIE researchers in Wachtberg are working on a solution through the 3D-InAus project. A robot equipped with a LiDAR (light detection and ranging) laser examines the surroundings. LiDAR technology measures distances by scanning the environment using light pulses.
This creates a 3D model that includes buildings, rooms, open spaces, and objects, along with their dimensions and relative positions. Users can navigate the 360-degree visualization with a joystick to explore the virtual world.
Compared to robot systems that use cameras to explore a danger zone, our project goes a big step further. The laser pulses supply measurements for precision 3D cartography of an area of terrain or building. Distances and dimensions are not estimated but instead determined with accuracy down to just a few centimeters.
Timo Röhling, Technical Project Manager, Cognitive Mobile Systems Department, Fraunhofer Institute for Communication, Information Processing, and Ergonomics FKIE
Geometric Point Cloud Derived from Laser Pulses
A LiDAR laser mounted on a turntable is the system’s central component. The LiDAR module includes a rotating mirror that scans a region ten times per second, divided into sixteen vertical segments or "slices."
The turntable rotates the laser to provide a complete 360-degree horizontal view. The system generates 1.3 million laser pulses per second, calculating distances based on the time delay of reflected pulses.
The LiDAR module is mounted on a vehicle that operates in either continuous or stop-and-go mode. Continuous mode is faster but less precise. The output is a three-dimensional point cloud, where each point represents a laser pulse or distance measurement. A camera system, with up to six cameras, captures images that are used to add color to the corresponding objects or shapes.
“You might think of us melding the camera images and point cloud together. This gives us a vivid, detailed, and also geometrically accurate 3D environment showing buildings, open space, and objects,” Röhling added.
A computer module on the robot pre-processes the raw LiDAR data before the mission is complete. The final visualization is created during post-processing on a stationary system. Mapping a 400 x 400 m area typically takes about three hours, but a preliminary overview can be generated in as little as one hour during emergencies. Multiple vehicles can operate simultaneously to expedite the process.
The Bundeswehr, which commissioned the project, benefits from this 3D mapping technology. It provides detailed situational overviews of new terrain or danger zones, enhancing safety for service members. The system’s software can also process data from sensors detecting hazardous gases or radiation and display the results on 3D maps.
Virtual GPS inside the Building
The robot system is controlled via radio using a joystick and tablet. If radio contact is lost, the system can navigate autonomously. Indoor navigation is particularly challenging due to the lack of GPS reception. To address this, the researchers use pre-mapped building dimensions to create a virtual GPS for indoor environments, allowing autonomous navigation within structures.
The Fraunhofer FKIE team used their years of experience in robot-assisted modeling of 3D settings to complete the project.
“We came up with the concept, selected the components, and implemented the algorithms,” Röhling explained.
Flexible Platform for Different Scenarios
The system was designed with adaptability in mind. The laser module and turntable can be mounted on various vehicles, including wheeled, tracked, or drone-based platforms, depending on the terrain. This modularity allows users to customize the system for specific scenarios, ensuring flexibility across different environments.