Build log
Through a narrow door.
Alkyon folds its arms to slip through gaps its open shape would not pass. On paper that is geometry. Doing it with real sensors, real motors and moving air is another matter.
In short. In still air, in simulation, Alkyon passes narrow gaps without touching them, and when a gap is too tight to pass with a margin, or it is not sure, it stops in front and says so. Moving air is the hard case, and the one we are working on now.
The easy part
Two propellers side by side cannot be narrower than their own width, and that sets the narrowest shape, H, with the arms folded along the body. The geometry is the easy part. The hard part is knowing exactly where the gap is, and staying in its middle.
How it lines up
The robot measures the doorway with its own sensors, lines up with it before it goes in, and keeps to the middle while it passes, using what it sees at that moment rather than its map. It opens its arms only once the gap is behind it.
What the simulation says
In still air, at the widths we design for, it passes without touching, and when its readings leave any doubt it stops short instead. At the very edge of what it can manage, it usually reads the gap as too narrow and backs out, but it has also misjudged the opening on the way in, and that is what we are fixing next. Narrower than that, it refuses: it stops in front and reports.
The hard case: moving air
Homes are not still. A fan, an air conditioner or an open window pushes on a robot this light, and a draft aimed at the door is still the hardest case in our simulation. Our latest controller cuts the contacts in drafts sharply, but not yet to zero. We are designing Alkyon to wait, or take another way, when the air moves more than it can handle.
What these results are
Simulation, with realistic sensing, motor delays and position errors, and air models taken from the literature rather than measured. The effect of a nearby wall on the airflow is still unmeasured, and it matters. The test stand will tell us how far to trust all of this; until then, everything here holds for still air and nothing more. More on Alkyon’s shapes.