3D video content has a significant limitation, one that is not trivial to solve. Video captured by a camera — even one with high resolution and a very wide field of view — still records a scene as a flat plane, from a fixed point of view. The limitation this brings will be familiar to anyone who has watched a 3D video (or “360 video”) in VR and moved their head the wrong way. In these videos one is free to look around, but may not change the position of their head in the process. Put another way, pivoting one’s head to look up, down, left, or right is fine. Moving one’s head higher, lower, closer, further, or to the side? None of that works. Natural movements like trying to peek over an object, or moving slightly to the side for a better view simply do not work.
In November 2017, we showed you [Chris Annin]’s open-source 6-DOF robot arm. Since then he’s been improving the arm and making it more accessible for anyone who doesn’t get to play with industrial robots all day at work. The biggest improvement is that AR2 had a closed-loop control system, and AR3 is open-loop. If something bumps the arm or it crashes, the bot will recover its previous position automatically. It also auto-calibrates itself using limit switches.
AR3 is designed to be milled from aluminium or entirely 3D printed. The motors and encoders are controlled with a Teensy 3.5, while an Arduino Mega handles I/O, the grippers, and the servos. In the demo video after the break, [Chris] shows off AR3’s impressive control after a brief robotic ballet in which two AR3s move in hypnotizing unison.
[Chris] set up a site with the code, his control software, and all the STL files. He also has tutorial videos for programming and calibrating, and wrote an extremely detailed assembly manual. Between the site and the community already in place from AR2, anyone with enough time, money and determination could probably build one. Check out [Chris]’ playlist of AR2 builds — people are using them for photography, welding, and serving ice cream. Did you build an AR2? The good news is that AR3 is completely backward-compatible.