Researchers at the Fraunhofer Institute for Communication, Information Processing and Ergonomics FKIE are advancing robotic exploration of hazardous zones through the 3D-InAus project. Equipped with LiDAR laser technology, these mobile robots emit laser pulses to map their surroundings and generate geometrically accurate 3D models. The system is designed to assist in emergencies, such as chemical plant incidents or flooding, where entering the scene may pose significant risks to human responders.
LiDAR technology uses light pulses to scan the environment and measure distances, producing detailed 3D models of buildings, rooms, open spaces, and objects, including their dimensions and distances. Users can navigate these 360-degree visualizations in real time using a joystick.
“Compared to robot systems that use cameras to explore a danger zone, our project goes a big step farther,” explained Timo Röhling, a technical project manager in Fraunhofer FKIE’s Cognitive Mobile Systems department. “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.”
How the LiDAR System Works
At the core of the system is a LiDAR laser mounted on a turntable. A rotating mirror within the LiDAR module scans 16 vertical sections, or “slices,” ten times per second. The turntable rotates the laser horizontally, enabling the vertical sections to provide a full 360-degree view. Altogether, the system emits 1.3 million laser pulses per second.
These pulses reflect off surrounding objects, and the time lag between emission and reflection is used to calculate precise distances. Mounted on a vehicle, the LiDAR module operates in either continuous or stop-and-go mode. Continuous mode provides faster results with slightly reduced accuracy, while stop-and-go mode delivers higher precision. The resulting data forms a 3D point cloud, where each point represents a laser pulse or distance measurement.
To enhance visualization, the system integrates images from up to six cameras. These images are used to overlay color onto associated objects or shapes within the 3D map. “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 spaces, and objects,” Röhling added.
Emergency Services and Military Applications
The raw data collected by the LiDAR system is pre-processed onboard the robot and finalized during post-processing. Mapping a 400 x 400 m area typically takes about three hours. In time-sensitive scenarios, an accelerated mode can produce an initial overview in as little as one hour. Multiple vehicles can also be deployed simultaneously to expedite exploration and mapping.
The system is valuable for both emergency services and military operations. The Bundeswehr, which commissioned the research, uses the technology to create complex situational overviews of unfamiliar terrain or hazardous zones, helping to reduce risks to personnel. Additionally, the system’s software can process sensor data to detect gaseous toxic substances or radiation sources and map their locations onto the 3D models to enhance situational awareness and improve safety.
Virtual GPS for Indoor Navigation
The robot system is typically controlled via radio by an operator using a joystick and tablet. For scenarios where GPS reception or radio contact is unavailable, such as indoor exploration, the system can operate autonomously. By referencing the building’s known dimensions from terrain mapping, the software generates a virtual GPS for the building interior, enabling the robot to navigate autonomously within the structure.
A Flexible Platform for Varied Scenarios
Fraunhofer FKIE designed the system to be highly adaptable for diverse terrains and applications. The laser module and turntable can be mounted on a variety of platforms, including wheeled or tracked vehicles and drones, depending on operational requirements. The system’s modular components allow users to configure it to meet the specific needs of each scenario.
The team’s expertise in robot-assisted 3D modeling was key to the project’s development. “We came up with the concept, selected the components, and implemented the algorithms,” Röhling said.
For more information, please click here.
- Fraunhofer Institute for Communication, Information Processing and Ergonomics FKIE (fkie.fraunhofer.de)
(Editor’s Note: All trademarks mentioned in this article, including company names, product names, and logos, are the property of their respective owners. Use of these trademarks is for informational purposes only and does not imply any endorsement.)
