I thought pretty hard about trying to do this some years back. My concept was more of a suspended gondola (which itself could triangulate to any point on the side of a building by having two winches + cables) with several tethered drones attached which would scrub windows and cling to them with suction. The gondola would provide power, cleaning solution and a waste return.
It's interesting that they went with climbing, but I'm sure it doesn't work on all facade types.
I thought pretty hard about trying to do this some years back. My concept was more of a suspended gondola (which itself could triangulate to any point on the side of a building by having two winches + cables) with several tethered drones attached which would scrub windows and cling to them with suction. The gondola would provide power, cleaning solution and a waste return.
It's interesting that they went with climbing, but I'm sure it doesn't work on all facade types.