3 ms·

The bread and butter of the industrial robotics industry is SCARA machines for pick 'n place. These commonly don't have any sensors beyond a few rotary encoders

The bread and butter of the industrial robotics industry is SCARA machines for pick 'n place. These commonly don't have any sensors beyond a few rotary encoders and motor feedback. They're just moving between preprogrammed points. It's hard to make a simple definition that includes everything.

dekhn 9y ago
"These commonly don't have any sensors beyond a few rotary encoders and motor feedback." you contradicted your own point. Those are sensors. Without them the P&P wouldn't be able to do its job.
- AlotOfReading 9y ago
  I could take the encoders out and the robot would work fine. Its position would just grow increasingly inaccurate over time and make the production line more fragile. It would also make writing the pick n place code a bit of a pain for several reasons, but they're not fundamental to the design.
  - gugagore 9y ago
    I mean... the robot would decidedly not work fine without joint encoders, on any timescale relevant to the task. You likely could not accomplish one pick/place operation. You need the position feedback because you don't have a good enough model of the motors (and everything) to do feedforward control alone. So I'd say position feedback is pretty fundamental to the design. (If you have stepper motors, then okay, you do have a good enough model of the motors.) I think I agree with your point at large, though, that the "proprioceptive" sensors of the robot don't have anything to do with the environment the robot is in, or the task at hand. But now what about an air conditioner with a thermostat? That's got a sensor and an actuator and the sensor in this case really is fundamental to the task at hand.
    - dekhn 9y ago
      a thermostat, under my definition would indeed be a robot- although a fairly boring one since it doesn't move itself, just modulate room temperature.
      - taneq 9y ago
        A toilet cistern would also qualify. (And in fact, while I wouldn't deem it a robot, I often use this as the simplest possible control system example.)
  - dekhn 9y ago
    nope, encoders are definitely fundamental. You cannot give a DC (brushed or not) motor voltage and have it turn a fixed distance. The closest thing is steppers, but once they stall, you've lost feedback and positioning information.

dekhn 9y ago

"These commonly don't have any sensors beyond a few rotary encoders and motor feedback." you contradicted your own point. Those are sensors. Without them the P&P wouldn't be able to do its job.

AlotOfReading 9y ago
I could take the encoders out and the robot would work fine. Its position would just grow increasingly inaccurate over time and make the production line more fragile. It would also make writing the pick n place code a bit of a pain for several reasons, but they're not fundamental to the design.
- gugagore 9y ago
  I mean... the robot would decidedly not work fine without joint encoders, on any timescale relevant to the task. You likely could not accomplish one pick/place operation. You need the position feedback because you don't have a good enough model of the motors (and everything) to do feedforward control alone. So I'd say position feedback is pretty fundamental to the design. (If you have stepper motors, then okay, you do have a good enough model of the motors.) I think I agree with your point at large, though, that the "proprioceptive" sensors of the robot don't have anything to do with the environment the robot is in, or the task at hand. But now what about an air conditioner with a thermostat? That's got a sensor and an actuator and the sensor in this case really is fundamental to the task at hand.
  - dekhn 9y ago
    a thermostat, under my definition would indeed be a robot- although a fairly boring one since it doesn't move itself, just modulate room temperature.
    - taneq 9y ago
      A toilet cistern would also qualify. (And in fact, while I wouldn't deem it a robot, I often use this as the simplest possible control system example.)
- dekhn 9y ago
  nope, encoders are definitely fundamental. You cannot give a DC (brushed or not) motor voltage and have it turn a fixed distance. The closest thing is steppers, but once they stall, you've lost feedback and positioning information.