For those who’ve been following together with Will Cogley’s unbelievable work on YouTube, you’ll know that he has managed to make a very unbelievable robotic/animatronic humanoid head. It has an absurd variety of servos crammed into the cranium and is able to very lifelike facial expressions. However till now, it was only a head and that restricted its potential. In his latest video, Cogley expanded his design so as to add a neck. He engineered the neck with inspiration from human anatomy and a Stewart platform.
A Stewart platform is an fascinating kind of manipulator consisting of six actuators (normally hydraulic arms or linear actuators) linking two plates. The actuators are in a form of “zig zag” association that allows six levels of freedom between the 2 plates — that means the highest plate may be set to any angle (relative to the underside plate) and likewise transfer in all three axes.
Whereas learning a human anatomy textbook for inspiration, Cogley realized that the muscle tissue connecting the neck to the torso have an association much like a Stewart platform, in the event you squint exhausting sufficient. That led him to this design, which is a neck that connects the top to the shoulders (a stationary base, for now) via six miniature linear actuators. That makes it so Cogley can program very lifelike actions.
He did his programming in Python and applied inverse kinematics algorithms, which let him enter a desired place and this system will work out how one can transfer the linear actuators to succeed in that place. A PC controls the linear actuators via boards of Cogley’s personal design. One is for energy distribution and it may output widespread voltages, because the neck motors have totally different necessities than the face motors. The second board is for motor knowledge management and it’s also configurable for various voltages.
However there was an issue: the geometry wasn’t preferrred for a Stewart platform, as Cogley needed to prioritize a human look over stability. That resulted in considerably jerky motion. The answer was to combine a backbone that mirrors a human backbone — offering assist whereas nonetheless being versatile. Cogley 3D-printed the person vertebrae in inflexible plastic, then related these with versatile discs 3D-printed in TPU. It took some trial and error to get the pliability of the discs good, however the synthetic backbone turned out very nicely.
Now Cogley has a totally actuated neck to match the remainder of the top, which can dramatically improve the sophistication of the robotic. And at this charge, we will solely assume that he’ll transfer on to the torso subsequent.
