Hand/Finger motion detection

Hello,

I toying with the the idea for a project. I want to be able to directly control a robotic hand using my own, with the interface being a sort of glove-like device, with each finger on the robotic hand mimicking the real counterpart in real time.

Now, one of my professors suggested using accelerometers for this, which seems plausible. However, I'm thinking these would also detect any other movement of the arm as well, resulting in undesired responses. Any suggestions? (I hope my description was wasn't too vague.)

Hello Pete,

Something like this is being developed in medical robotics for surgery already, although I am not sure how advanced this is. See for example (link should be one line):

http://robotics.eecs.berkeley.edu/medical/research.html

As a more specific reply to your question, you want to mimic the movement of your fingers, but not your whole arm movement. That is, you want to mimic the movement of your fingers relative to some point on your arm or hand. An obvious solution would be to use accelerometers to monitor the movement of this 'reference point' (forearm or palm of hand?) as well, and then subtract this movement from the measured 'global' finger movement to get the relative finger movement. With all the coordinate transformations required, this sounds like fun!

Alternatives may be to use flex sensors (as in Berkeley web site), or to use small (if they exist) potentiometers or other angle sensors for each finger joint, again back to your 'point of reference'. Of course, I am sure your professor has good reason to suggest accelerometers.

Good luck,
Gerrit

No, you described a wireless remote manipulator, also known as a Waldo, after the device described by science fiction writer and futurist, Robert A. Heinlein in his book _Waldo and Magic Inc._. You might want to look at resistive sensors instead of or in addition to accelerometers.

Good luck. I've wanted to see Waldos since I was a young teenager.

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The glove is off the shelf technology. Do a Google search on "glove haptic" and you will find a number of companies selling them, You will probably also find a number of research designs, in the event you want to build your own.

Most use sensors to measure the joint angle (up to several dozen sensors per glove). You could probably build a simple one with a few cable driven spring return linear sensors attached to the back of the hand and connected to the fingers of the glove.

Thanks for the suggestions. I might end up using those mentioned flex sensors (if not also something else) to detect finger movement, since they're only about $10 each.

I'm not looking for the utmost dexterity in the robot hand, but, say, enough to clumsily grasp an object. For simplicity's sake, I'd have the glove hardwired, especially since I'd be expected to construct my own.

-Pete