Early robotic hands were developed in part to mimic human grasping, but mostly to function in industrial environments where speed and force of operation were primary objectives.
More recently, some robot hand R&D has focused on closely emulating the human ability to pick up; manipulate; and move small, delicate objects in unstructured environments outside the factory safety cage. Many of these robots are being developed for use with humans, either in industrial environments, or as service robots for the elderly or disabled.
This requires robots that are smaller, safer, and human-aware at some level. Engineers developing the newer generation of robotic hands have re-thought the approach to hand design. Many have started with a higher-level view that attempts to emulate multiple integrated human biological systems, not only motor movements. The newer generation of robotic hands closely models the human hand's kinematics with a similar form factor, tactile and sometimes optical sensors, and high degrees of freedom (DOF) counts. Many have industry-standard interfaces and can be used as a tele-operation tool or mounted on a range of robot arms as part of a robot system. Some are commercially available, some were developed as proof-of-concept, and some are still in R&D.
Click on the image below to see 11 of these robots.
Based on the DLR Hand II, the German Aerospace Center (DLR) and the Harbin Institute of Technology (HIT) jointly developed the DLR/HIT Hand II as a medium-cost multisensory robotic hand. The DLR/HIT Hand II has five fingers, each with three actuators, that are identical except that one of them has an additional drive to make it work as an opposing thumb. To fully emulate human fingers' motor functions, each finger has four joints, not three, and each joint has force and position sensors. The DLR/HIT Hand II has a total of 15 degrees of freedom (DOF), compared to 13 in the original DLR Hand II. Fingers are equipped with slip-resistant gripper surfaces. Integration of drives and electronics within the hand itself is intended to make it easier to mount on a wide variety of robot arms.
(Source: German Aerospace Center (DLR))
Given that the post is "Robotic Hands Mimic Humans" and humans have pinkies, it would be good to include this appendage. I am not sure you would call the pinkie useless as it adds an additional control, like throwing a football. Yes it can be done without a pinky, but is it as precise?
Seems a lot of good designs already exist in nature and we just need to copy them to mimic them.
GTOlover, mimic doesn't mean "reproduce exactly," at least not in robotics. I was a little surprised that a pinky--i.e., a short final finger--didn't make the grade, but only a little. One of the main goals to be traded off in most of these projects was cost, so five digits weren't usually necessary. You don't need a pinky--as per definition given above--to throw a football, although a fifth finger is helpful. To throw it like a pro player? Yeah, it's probably needed. But that's not what these bots are built for. Plus, the functioning of only four fingers can be vastly improved over the human grasping system, as mentioned in a few of the slide captions.
GTOlover: When I think of the importance of a pinky on a robot, I always think of the scene from the movie Jurassic Park, where the robotic hands gently lift and re-position the dinosaur eggs. Pinkies definitely have an important role in minimizing handheld forces.
It's pretty incredible, isn't it, Chuck? We don't often think of robots creating art, mostly just performing mechanical tasks. So it's interesting to see a robot taking a different tack to do something purely for the sake of beauty. And not so scary, though, if you think that ultimately a human did create all of that! Funny, though, how we think of robots as their own, autonomous beings, and forget sometimes humans are behind them (in terms of programming, development etc.).
Your comment, Ann, makes me think about how much we can learn about human movement in the development of robots...even as engineers mimic human movement to develop robots. I would have never looked at the pinky quite that way, but it's true, isn't it?
Thanks for the link Elizabeth. That reminds me of the ABB robot arm painting people's dreams--actually, taking sensor data of sleeping people: http://www.designnews.com/author.asp?section_id=1386&doc_id=254180
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