Incredibly versatile active ball-joint gear is mind-bending
New Atlas | September 23, 2024 | Joe Salas

The ABENICS active ball joint gear allows for extremely precise, high-torque movement

At its core, this system developed at Yamagata University in Japan uses a “simple” cross-spherical gear paired with a monopole gear to control pitch, roll, and yaw. Essentially, the same full range of movement you’d see in a rotator cuff (the shoulder) of a human. With clever gearing, coupling, and sliding motions, the ABENICS gear is extremely precise in its movements.

By adding a second monopole gear and differentials in tandem, connected to a ball joint, this system becomes even more robust. Operators are able to achieve very precise, high-torque movement on the spherical gear with incredible accuracy.

If attached with an output link – like an arm or a leg – this means finite control over a very realistic joint in robotics for smooth and natural movement. Generally in today’s humanoid robots, two or more motorized joints are used in tandem for a shoulder: one to control up and down, one for forward and backward motion, and a third to control rotation.

ABENICS – Active Ball Joint Mechanism With Three-DoF Based on Spherical Gear Meshings, as it’s officially called – could simplify these joint structures, combining a full range of motion into a single joint.

ABENICS can roll, pitch, and yaw in every direction Yamagata University This type of gear hasn’t been widely adopted in any commercial, medical or industrial ventures as of yet. Although its focus has been mostly in academia and research, the technology shows very high promise for future use in areas where high torque, high precision, and three-dimensional freedom of movement are needed.

The implications of what robots equipped with ABENICS joints could do are boundless.

Among the comments:

The 2035 sex doll models are going to be great.

I like that previous guy.

But I like these next two guys, too:

The lubrication for gear boxes is centrally located, pumped out to all gearboxes, maintained in temperature (not too cold and not too hot), and the more the precision of motor speeds to the output rpm of that gearbox, (100 corrections per second) the more things get very, very, very, dicey. Better be careful because that motor will be hotter than Satan’s furnace after a few hours of that application connected to a VFD or servo. Several servo motors, one for each axis, connected to each other in motion control software like Allen Bradley Kinetix Drives would seem a whole lot smarter to me.

One motor with one output shaft connected to a dozen or so mechanically linked gearing applications has always been a hard crash disaster setup IMHO. To me this seems like a step backwards in technology.

At least troubleshooting will go easy. Getting everything back to zero or home will take hours. I just love a master servo motor with as many as hundreds of ethernet connected child axises always impressed me. Master motor homes in safe position. Each axis motor then home to matching safe positions. Then the system moves as one. A failure or crash triggers “Safe-Off”. Getting it all back is easy-peezy. The motor control software in Kinetix will even tag the axis that failed and the type of failure.

The only caveat is that your IT Department will have to give a few thousand dedicated (yet kept secret) IP Adresses for each axis for each machine in the entire factory. I had one machine with over 1,700 IP Adresses and 1,150 Axises to control. Cabinets and racks as far as the legs could carry me.

The most common downtime cause was when Kinetix and Poweflex would hit on duplicate IP Addresses. Some nitwit in an office would install his new printer or massaging chair and they would let an “install wizard” program snatch up an IP Address already in use. It may take an hour, day, or week, but when those duplicates check in with the master, you’re going down bigly. Then it takes days to find the unauthorized device on the network.

And you’re wondering why the IMAO site keeps going down.