4 ms·

A lot of the cost of a Barrett WAM arm (for example, they're popular in industry and research) is the controllers and motors. In order to get sufficient precisi

A lot of the cost of a Barrett WAM arm (for example, they're popular in industry and research) is the controllers and motors. In order to get sufficient precision for pick and place you either move very slowly, or fast with extremely high gains. High gains mean overshoot unless you can also run the control system at warp speed. All that combined means the solution is non-trivial, and the few companies that have solved it can sell it at the sorts of prices we quoted. As for computer vision, sure, it's possible. But an RGBD camera (e.g. Kinect) will be better. Condensing the explanation, these sensors project a grid of near-IR light using a laser, then use an IR sensitive camera to pick up the grid, noting that it is distorted by obstacles in the environment. These distortions can be used to determine the distance to corners in the grid. A normal RGB camera picks up colour, and putting it all together we get a 3D coloured image from a single frame. You cannot do that with a single camera in a single frame. You can do it with two cameras, but arguably its harder and more expensive.

tgflynn 15y ago
I agree that using a Kinect is probably a good early approach. 3D CV certainly isn't easy. If I were developing a product though I'd want to be careful about being dependent on one company's technology. I'm not sure how easy it would be to replicate a Kinect like device (whether for legal or technical reasons) and my impression is that high speed laser scanners are very expensive. If you'd like to continue this discussion my e-mail address is in my HN profile. I too am very interested in developing a robotics product. One of the things I'm really trying to understand is what exactly makes these arms so expensive and what, if anything can be done about it. You mentioned motors and controllers. I wonder which one drives the cost. With motors the problem might be materials and manufacturing cost, if its the controllers then I think the cost would be more in non-recurrent engineering (because electronics manufacturing usually isn't very expensive) and that can be minimized if you have a large market.

tgflynn 15y ago

I agree that using a Kinect is probably a good early approach. 3D CV certainly isn't easy. If I were developing a product though I'd want to be careful about being dependent on one company's technology. I'm not sure how easy it would be to replicate a Kinect like device (whether for legal or technical reasons) and my impression is that high speed laser scanners are very expensive. If you'd like to continue this discussion my e-mail address is in my HN profile. I too am very interested in developing a robotics product. One of the things I'm really trying to understand is what exactly makes these arms so expensive and what, if anything can be done about it. You mentioned motors and controllers. I wonder which one drives the cost. With motors the problem might be materials and manufacturing cost, if its the controllers then I think the cost would be more in non-recurrent engineering (because electronics manufacturing usually isn't very expensive) and that can be minimized if you have a large market.