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Comment by Isamu | Hacker News Reader

> if you have any other questions about exoskeletons or assistance devices

Thanks! So is getting good compliant force control the big thing here? What are the big hurdles for exos becoming more widely used?

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We value position control more than force control (i.e., controlling motors for force output used to be very popular, but nowadays controlling for position is in vogue, so to speak, although force and position are obviously related), but the big thing with exoskeletons is trying to build one that is as 'dynamic' as the human body - the best exoskeleton is the one that best approximates the novel mechanics of human locomotion (i.e., the way parts of the body move in relation to one another) as well as the means by which locomotion occurs (i.e., how muscle groups interact to cause extension and flexion), and also has a dynamic relationship with the user. Current exoskeletons, including B.b's, are what I would describe as very rigid and non-ergonomic in design, although to the credit of b.b, suitX is at least an improvement in some regards.

Very briefly, the things holding back exos are

- regulatory process is a five year process, minimum, so anything coming out today is using at least 5 year old designs etc, and also means fewer players can afford to undergo the process (fda, patents, etc)

- state of the art is held back by poor designs and construction methods

- lack of focus/v.c $$ in the field

I suspect within the next decade we will see a revolution in this field, but for now, this is what we've got.

> lack of focus/v.c $$ in the field

I don't doubt it, but interesting that this is the case

Would there be any benefit to not try to replicate human movement directly? For example, maybe balance would be easier by adding a "tail" that drags along behind with a small wheel under it.

I would think that the main benefits that people would look for over a wheel chair, are being able to go over uneven surfaces / stairs, and being at the right height to reach things.

I'm imagining a system where the user is strapped to a seat of a machine with the legs slightly bent and in front, and and the machine's two legs maneuver by telescoping. That way, you need one motor to control how far a leg is extended, and another one to control forward swing. The tail would help with balance, and also hold the battery pack.

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