Yeah that’s not gonna stay on well enough, especially since the chair youve got on there doesn’t have anti tippers. Look into “transit ties” designed for wheelchairs to go on buses.
Thanks for the advice. Yes, one of the requirements of this project is that it needs to be compliant with Section 38.23(d) of the DOT ADA. This is just a prototype, we understand that additional work needs to be done.
As a wheelchair user, i have some additional thoughts:
-Can it fit through standard doorways?
Yes! This is also one of our requirements (and one I encourage for all of our FRCFIRST Robotics Competition robots as well).
-Where is the large, easily accessible, kill switch button? It needs one hardwired to immediately cut the power from the battery for safety.
In the right side of the GIF, you can see a black cord resting in the seat of the chair. There is a kill switch with ~8 feet of wire connecting it to the chair that the therapist will hold at all times. We’ve also discussed the possibility of using a wireless relay to kill power to the motors.
-Bumpers? Doesn’t have to be frcFIRST Robotics Competition style but something to prevent wall/ankle damage
Yep! There’s a ring of black foam around the outside of the platform.
-Can you switch out the chair? The vast majority of wheelchair users use an “active ultralight” chair with therapeutic cushion/positional adjustments. You’ve got a “hospital style” chair which is designed as a one size fits all but lacks important safety elements like seatbelts and pressure reducing cushions individual to the person (not everyone can safely sit in a hospital style chair even for a little bit)
Great question! Yes, there’s a lot of variety in the types of chairs that the students at ACCEL use, so our solution requires that it be adaptable. The chair that is shown in the GIF is not typical of what the students use. Many of the students use different variations of the wheelchair you described. ACCEL didn’t have any extra wheelchairs for us to use in the prototype, but the students had access to this chair, so that’s what they decided to use for these initial tests.
-How do people get on it? If the answer is they have to transfer into the chair or get lifted into it, this will only work for ambulatory people or with two people to help lift and you’re gonna miss the opportunity to help most of the people in the intended user audience. The vast majority of people who are eligible for a powerchair won’t be able to get onto this unassisted unless a ramp gets integrated (Ideally a ramp that becomes the back safety railing folded up)
Yes, there is a ramp! This is not the best photo of it (it’s resting on its side), but it gives you an idea of what it looks like. They are still working on the final design for this as well.
-Does it use a standard powerchair joystick? It’s useless for practice unless the joystick is the same
This is a good point. ACCEL actually asked us to create the controller using the five arcade buttons rather than a standard joystick. My understanding is that some of their students may not have the fine motor control to use the joystick, but they can activate the buttons. I’m assuming they have a way to adapt these wheelchairs to use a similar interface, but it would be good to get more clarification on that. Either way, if we had to change the code to use a joystick, it would not be a major change. Thanks for the feedback!
One thing I would be concerned about is- will there be something preventing it from rolling off the base? From the photos, it doesn’t look very secure- and one lesson I’ve learned is to never 100% rely on the wheelchair brakes, but also I’m very paranoid 
