3 ms·

There is lots of research pointing out that the problem may in fact be trying to do that at all. A significant issue with this is that humans can't do precision

There is lots of research pointing out that the problem may in fact be trying to do that at all. A significant issue with this is that humans can't do precision positioning of limbs in free space, yet can carry out all the tasks people want to use these robots for. When you see surgeons, who have loads of theory about precision movements you will quickly find that they rely on feedback rather precision for their movements. For example, they cut along the "linea alba", not by knowing where it is and positioning the knife exactly, but by simply slicing down starting at a good enough position, knowing the knife will follow the linea alba because it's attracted to it. Which is a fancy way of saying that it's a force feedback problem, not a positioning problem.

tgflynn 6y ago
Humans can be very precise when they need to be (ever try repairing any modern electronics ?) but yes they do that closed loop using both visual and tactile feedback.
- candiodari 6y ago
  They can't really. If I were to tell you to position your arm -5cm, 0cm, 0cm relative to your nose, I'd be impressed if you got the three numbers to match while passing through them. Holding a plate at that position for a minute while I put 1kg worth of objects on it is out of your capabilities. You use an object to move precisely around it. Not just visual feedback but (when I repair electronics I) use the electronics to keep most of my muscles in place, while only moving one or two, and not very precisely at that, I always need to correct things afterwards. Stopping is done using force feedback (hitting something), in case of soldering even smell comes into the picture. I can hit a 2mm square target reliably with my an instrument held by my fingers (and my hand resting or held in place) and, say, a 2cm target with my hand. I get that I'm probably not surgeon material, but let's say they can double or triple that accuracy. 10x is out of range of any human without robotic help. Robots are expected to do that with three numbers behind the decimal point and to keep that position, while carrying their load (varies from 200gr to 20ton). There is no way a human can do that, not even with 200gr, to an accuracy of a centimeter. And even trying will be so stressful you wouldn't be able to hold it for even a minute. A robot can hold it for 10 years.

tgflynn 6y ago

Humans can be very precise when they need to be (ever try repairing any modern electronics ?) but yes they do that closed loop using both visual and tactile feedback.

candiodari 6y ago
They can't really. If I were to tell you to position your arm -5cm, 0cm, 0cm relative to your nose, I'd be impressed if you got the three numbers to match while passing through them. Holding a plate at that position for a minute while I put 1kg worth of objects on it is out of your capabilities. You use an object to move precisely around it. Not just visual feedback but (when I repair electronics I) use the electronics to keep most of my muscles in place, while only moving one or two, and not very precisely at that, I always need to correct things afterwards. Stopping is done using force feedback (hitting something), in case of soldering even smell comes into the picture. I can hit a 2mm square target reliably with my an instrument held by my fingers (and my hand resting or held in place) and, say, a 2cm target with my hand. I get that I'm probably not surgeon material, but let's say they can double or triple that accuracy. 10x is out of range of any human without robotic help. Robots are expected to do that with three numbers behind the decimal point and to keep that position, while carrying their load (varies from 200gr to 20ton). There is no way a human can do that, not even with 200gr, to an accuracy of a centimeter. And even trying will be so stressful you wouldn't be able to hold it for even a minute. A robot can hold it for 10 years.