A year ago, I built an animatronic hand for a competition. While it worked, the design was clunky and the flex sensors used to control the device weren't as accurate as I had hoped.
In the video, the design uses strings in order to measure the movement of the hand. I was wondering what are those sensors that are measuring the pull of the string and if it would be feasible in my project.
Thank you.
Alas their paper mentions only the robot hand, not the sensors they used for the video.
I'd hazard a guess they have some small torque motors and strings and encoders to sense with.
A torque motor is one set to a constant torque, here ensuring the string is spooled onto a little drum
whose rotation is sensed by an encoder - certainly the mechanical set-up looks like there are motors
and rotating parts.
Any DC motor can be turned into a torque motor if you put a constant current through it - for instance
using a stepper motor chopper-drive module like a DRV8825. Torque motors in industry are typically
used similarly to take up the slack and are often designed for stalling continuously without issues.
I have used string pots that look like the sensors in the video.