Even if you could get around the payload and energy density (power autonomy) constraints, which are very stringent, this seems like a dead product. Sure, it’s a cool project for some controls engineers. But I can scarcely imagine the deafening noise this thing makes, and no doubt it would tend to kick up clouds of dust anywhere it went, which is hardly desirable from a health perspective. This kind of device would be a permanent irritant in almost any environment. Thankfully, buildings are already well equipped with things like elevators. I’ll keep my wheeled cart, thank you very much.