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by mft_
336 days ago
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This looks like a nice, approachable robotic model of a human hand that can be printed and experimented with. But... is a human hand the best design for a robot to grip things with? Or could we surmise that the human hand evolved as a pretty good hand given the materials and senses that were available to evolve humans from, while in theory a totally different design might be optimal for gripping when constructed from metal, plastic, motors, etc.? |
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For any one specific thing, be it a doorknob, a rope, a sheet of paper or fabric, or a pair of scissors, there's probably a different design that's several orders of magnitude simpler and cheaper, and also much stronger and more reliable. Single-axis parallel grippers, circumferential chucks, vacuum cups/vacuum pads, electromagnets, cam lock and release mechanisms, and so on are common in industrial robotics.
Assume your robot's only task is to grab a spool with a 35 +/-0.5 mm ID core from from an infeed rack and place it on a spindle, you're not going to try to build a five-finger human sized servo-operated hand and tuck two of those fingers away to awkwardly pinch outwards from the inside, you're going to grab a Schunk JGZ concentric gripper off the shelf and plumb a pair of air lines to it. If it also needs to grab a tab from some tape on the spool and pull it into the machine, you're just going to add an asymmetric pincer like an angular tumor on two of the jaws - or graft on an entire separate parallel gripper like some polydactyl appendage, or tool-change, amputating and reattaching hands at will.
I have also observed that humans are quite good at anthropomorphizing robot arms: a small, well-tuned motion can be universally recognized as a nod of agreement, shrug of confusion, wave of acknowledgement, or sigh of disappointment, even if the equipment is a bright yellow 6-axis piece of cast iron with menacing claws where the hand (or face? they're often the same) should be. Googley eyes and a "Hi my name is" sticker make this even more convincing.
But if you need a single tool to grip a doorknob, a rope, a sheet of paper, a pair of scissors, AND an unknown variety of other arbitrary household objects... it's probably best to start with an approximation of the human hand. Also, while claws may be appropriate for a work environment with the robot inside a fence, in collaborative situations hands are just less intimidating.