In the harsh conditions of underground tunnels, avoiding collision is crucial. In such an environment, however, camera-based solutions come up against their limits. For this reason, METALLIANCE (CORAIL-TUNNELIER) turned to 3D LiDAR technology from SICK to detect obstacles in their upcoming excavation project.
When excavating tunnels, collision avoidance not only becomes increasingly important, but also increasingly difficult. The main challenge in such projects is implementing an obstacle detection system that complies with ATEX requirements (allowing work in an area with risk of explosion). This involves, among other things, utilizing an anti-collision system compatible with these requirements, or integrating such a system into a sealed and compliant box.
In the past, METALLIANCE, a company that designs, industrializes, manufactures and markets mobile machinery for underground work, had used camera-based anti-collision technology. Not only did using these systems in this environment bring certain constraints, but it also required the use of an air-cooling system. These challenges prompted the company to turn to SICK to provide multi-layer LiDAR technology for a recent project.
At the end of 2023, METALLIANCE agreed to support the excavation of four railway tunnel sites. The company had previously invented the Rubber-tired Train (TSP) for this purpose. The goal was to equip each of the two cabs of a TSP, known as a train on tires, with a new obstacle detection system. This would provide driving assistance to operators and guarantee the anti-collision function.
SICK recommended the use of the multiScan165, part of the multiScan100 product family. Not only does the sensor ensure a sufficient number of layers to guarantee obstacle detection, its characteristics make it particularly well suited to the application. Its small footprint facilitated its integration into a glass housing, while its shock resistance made it suitable in this harsh use environment. Plus, thanks to its low heat dissipation, it doesn’t require an additional cooling system. These benefits made the multiScan165 the clear choice for METALLIANCE and the company soon began to carry out initial tests of traversability and evaluations of signal stability.
The multiScan100 product family’s multi-echo technology combined with the stability and quality of the measurement data allowed METALLIANCE to ensure reliable detection through the glass housing. The competitive package of the multiScan100 product family also opens up other deployment prospects for METALLIANCE in the future.
As the driving environment in tunnels is very constrained, drivers have to pay particular attention to ensure that the large TSPs and their loads are properly handled. To assist with this, all TSPs are equipped with an anti-collision system.
The TSPs’ sensors are optimized to the very harsh conditions of the environment in which they operate. For example, the sensors are able to handle interference from the parasitic reflections that can result from the surrounding metal of the tunnel structure. Meanwhile, contamination detection tells drivers whether the lenses need to be cleaned due to dirt, the humidity of the ground or potential splashes and dust resulting from the excavation work.
The multiScan165 offers a greater working and analysis range than the current camera-based solution. This range makes it possible to better anticipate the analysis of obstacle detection and to allow the machines to move at greater speeds.
In the future, METALLIANCE envisions the integration of multiScan165 as a standard on all Operator Assistance machines. That said, the ways it will be integrated will certainly vary greatly. In other applications, METALLIANCE will be able to take advantage of the total 360° aperture angle, and thus the additional features such as guidance assistance. According to the company’s ambitions and development prospects, the multiScan100 product family could be one of the first steps toward a fully autonomous driving system.
