Shadow Arm
I met the guy who runs the shadow project some years ago at an exhibition - a white haired fellow with a home counties accent. They had a demo of their walker robot which was an incredibly complex looking thing, and also an early version of the anthropomorphic arm. The arm was really quite impressive, and I've still got some photos of it here on the wall.
I also chatted with one of the guys who made some of the robots. He said that the air muscles were rather unreliable (they kept leaking) and would gradually change their shape with use, so that repeatability of the actuator was poor. Like most pneumatically drive actuators you can have an "on" and an "off" position, but getting a decent level of control anywhere inbetween is a bit of a black art. They were also rather vague about how the robot would be powered (you need a big - usually petrol driven - compressor which
isn't exactly portable).
Nevertheless the shadow project does seem to have some talented engineers and their demos were quite impressive despite the technical hiccups.
If they're serious about making a robot for helping people in the home though they do need to do some work on the actual price of their arm. If you look on their web site it has a $90000 price tag, which I would guess is way beyond the budget of the average dissabled person (or anyone else for that matter). I bet the actual cost of the materials which make up the arm is only a tiny fraction of that. The air muscles themselves are very cheap and constructed from a rubber balloon surrounded by a wire gause, and the rest of the construction is aluminium, plastic and wood. So I bet the majority of that cost is labour. If they standardised their design, rather
than each one being a bespoke application, they could probably cut the abour cost significantly.
- Bob
|