The Danish Technological Institute (DTI) has taken a robot underground in Mønsted Kalkgruber - the world's largest limestone mine. The robot was used to take 3D measurements which can make one of Denmark's most popular tourist attractions more aware of the size and layout of the limestone caves.
Robot specialist Jonas Bæch went 35 meters underground in Central Jutland, where around 60 kilometers of mine tunnels permeate the calcareous subsoil.
Jonas fitted one of today's most all-terrain robots, Spot, with advanced sensors, then challenged it to map the mine network. The goal is to discover new possibilities and limitations with the technology in a dark, hilly environment with challenging surfaces.
– Until today, mobile robots are best known for being able to roll around in flat environments. We would like to challenge that and help push the limits, as it can open up a sea of new application possibilities, says Jonas Bæch from DTI.
– The underground passages in Mønsted Kalkgruber are an exciting opportunity to test algorithms, sensors and robotic technology in difficult terrain, he adds.
From estimation to scanning
Mønsted Kalkgruber is a winter hotel for 15,000 bats between November and April, but then opens its corridors to around 85,000 tourists per season. In fact, Mønsted Kalkgruber has been named one of the world's most popular tourist attractions, and in order to maintain its position on that list, the managers constantly want to make things better. They have therefore been excited to see the 3D scan from the robot's underground adventure.
– We can use the measurements from the robot to become smarter about the actual conditions in the caves and guide our guests better. Much of the material we have today is based on estimates and approximate calculations, says Tina de Linde, director of Mønsted Kalkgruber.
– In addition, we also think that it will be possible to increase the safety level still further if we can correlate the above-ground location of various underground points more precisely with the true underground positions, she adds.
The robot Spot - equipped with a LiDAR sensor - generates a map of Mønsted Kalkgruber.
Use scenarios for all-terrain robots
DTI has tested mobile, all-terrain robots in many different scenarios – for example for assisting emergency services, as a guide dog for the blind, as a helping hand on the construction site and as a boundary inspector at the airport.
Based on the experience gained so far, one of the scenarios where Jonas Bæch sees the greatest potential for the all-terrain robots is in the role of mapping in three dimensions.
– There are particularly interesting perspectives in being able to automate visual, repetitive registration tasks – for example in the construction industry, where there is much to be gained if errors are discovered early in the process, says the robot specialist.
Jonas Bæch mentions a concrete example here, where DTI has tested a robot as a data collector on a construction site.
Employees on large construction sites spend around 250 hours a month manually registering buildings with laser scanning and photography in order to document the quality and progress of construction. A task a robot could perform with great benefit.
Under the ground
How did the underground challenge in Mønsted Kalkgruber go for Jonas Bæch and Spot?
– The robot passed the test, and our sensor algorithms and measurement exercise also worked as well as we had hoped, says Jonas Bæch happily.
– Currently, there are not many mines or other underground scenarios in Denmark, but our tests here show that robot technology has reached a stage of development which makes it worth thinking about application possibilities outside the factory floor, he concludes.