Adaptive systems research group

Dynamic fleet mission planning
This video illustrates our dynamic fleet mission planning method, for autonomous underground mining operation. The video shows, at 20x the actual speed, the first hour of a four-hour shift in the mine shown in the figure below.

Note that the map is topological. For example, the vertical section in the left-hand side of the map would, in reality, be a spiralling path leading down to the lower levels of the mine. The red nodes are terminals. The left-most red node is the offloading terminal, where vehicles dump material for crushing, whereas the other red nodes are loading terminals deep in the mine, where vehicles pick up material. The yellow nodes are pause nodes where (outgoing) vehicles can stop in order to let another vehicle pass. The blue nodes are transit nodes, where a vehicle has a choice between (at least) two different directions. Note that only outgoing (empty) vehicles are allowed to stop at pause nodes in this way: Incoming (loaded) vehicles always drive along the shortest path towards the offloading station (however, in cases where the offloading station is occupied, incoming vehicles are allowed to stop temporarily at a non-occupied pause node near the offloading station.

Vehicles that reach a terminal (either a loading site or an offloading site) can request re-optimization, once they have completed their stationary activity (loading or offloading). At that point, the optimizer generates a new mission for the vehicle in question, while also (potentially) modifying the missions of the other vehicles. Thus, the planning method must be able to handle the fact that vehicles move during optimization and must make sure to maintain causaility, by only making changes in those parts of the missions that lie beyond the end time of the optimization procedure.

Note also that the video has been speeded up by a factor 20. The actual traversal times are on the order of 7 - 15 minutes. For this rather small mine map, with a single off-loading station, 4-5 vehicles is close to the upper limit of what is reasonable. However, in bigger maps, the fleet mission optimizer can handle larger number of vehicles as well.

Note: In the video, all nodes are shown in cyan color, in order to make the positions of the vehicles clearer.

Dynamic map
The topological map used when generating the videos. Terminals are shown in red, pause nodes in yellow, and transit nodes in blue.
Note that the only prioritized terminal is the one at the upper left corner of the image.

Last update: 20180312, 08.00