This sounds a lot Jaybridge, acquired by Toyota Research. They had things like grain trailers driving next to harvesters until full, then driving to the edge o

This sounds a lot Jaybridge, acquired by Toyota Research. They had things like grain trailers driving next to harvesters until full, then driving to the edge of the field for pickup... also Giant Dump Trucks, operating within open mines. (These were just marketable examples, I believe the internals were quite general, in the context of "adding autonomy to existing heavily specialized vehicles" without rebuilding them...)