Hinge joints are usually the simplest to use for robotic applications, but if you want motion that looks more organic, rolling joint (or rolling contact) mechanisms are worth a look. [Skyentific] is experimenting with this mechanism and built a 6-degree-of-freedom robotic arm with it.
The mechanism doesn’t necessarily need the physical surfaces to roll across each other to work, and you can get to two degrees of freedom with the virtual rolling sphere mechanism. [Skyentific] demonstrates how these work with both cardboard cutouts and 3D printed models. Stacking three of these mechanisms on top of each other, with each stage driven by three Dynamixel servos, the motion seems almost serpentine.
Since the servos are driving the small bottom linkages of each stage, they are operating at a significant mechanical disadvantage. The arm can just barely keep itself upright on top of the table, so [Skyentific] mounted it upside down to the bottom of the table to reduce the load of its weight. With the front stage removed, the load is significantly reduced, and it doesn’t struggle as much.
An interesting advantage of this mechanism is that there is always a straight path down the center for cabling. The length of this line between the two plates remains the same throughout the entire range of motion, so it can also be used to route a rigid drive shaft. This is actually what was done on the LIMS2-AMBIDEX robot to rotate its hand, and is also where saw this mechanism for the first time. Interestingly, that implementation didn’t drive the linkages themselves, but used tension cables around the mechanism. We also see this in a very similar tentacle robot, so it might be a better option.
Continue reading “Rolling Sphere Robotic Arm Seems Serpentine” →
Sisyphus is an art installation by [Kachi Chan] featuring two scales of robots engaged in endless cyclic interaction. Smaller robots build brick arches while a giant robot pushes them down. As [Kachi Chan] says “this robotic system propels a narrative of construction and deconstruction.” The project was awarded honorary mention at the Ars Electronica’s Prix Ars 2022 in the Digital Communities category. Watch the video after the break to see the final concept.
[Kachi Chan] developed the installation in pre-visualizations and through a series of prototypes shown in a moody process film, the second video after the break. While the film is quite short on details, you’ll see iterations of the robot arm and computer vision system. According to this article on the project [Kachi Chan] used Cinema 4D to simulate the motion, ROS for control, PincherX150 robotic arms modified with Dynamixel XM 430 & XL430 servo motors, and custom 3D prints.
We’ve covered another type of Sisyphus project, sand tables like this and the Sisyphish. Continue reading “Robot Repeatedly Rearranges Remnants In The Round” →
Humanoid robots always attract attention, but anyone who tries to build one quickly learns respect for a form factor we take for granted because we were born with it. Pollen Robotics wants to help move the field forward with Reachy: a robot platform available both as a product and as a wealth of information shared online.
This French team has released open source robots before. We’ve looked at their Poppy robot and see a strong family resemblance with Reachy. Poppy was a very ambitious design with both arms and legs, but it could only ever walk with assistance. In contrast Reachy focuses on just the upper body. One of the most interesting innovations is found in Reachy’s neck, a cleverly designed 3 DOF mechanism they called Orbita. Combined with two moving antennae at the top of the head, Reachy can emote a wide range of expressions despite not having much of a face. The remainder of Reachy’s joints are articulated with Dynamixel serial bus servos though we see an optional Orbita-based hand attachment in the demo video (embedded below).
Reachy’s € 19,990 price tag may be affordable relative to industrial robots, but it’s pretty steep for the home hacker. No need to fret, those of us with smaller bank accounts can still join the fun because Pollen Robotics has open sourced a lot of Reachy details. Digging into this information, we see Reachy has a Google Coral for accelerating TensorFlow and a Raspberry Pi 4 for general computation. Mechanical designs are released via web-based Onshape CAD. Reachy’s software suite on GitHub is primarily focused on Python, which allows us to experiment within a Jupyter notebook. Simulation can be done within Unity 3D game engine, which can be optionally compiled to run in a browser like the simulation playground. But academic robotics researchers are not excluded from the fun, as ROS1 integration is also available though ROS2 support is still on the to-do list.
Reachy might not be as sophisticated as some humanoid designs we’ve seen, and without a lower body there’s no way for it to dance. But we are very appreciative of a company willing to share knowledge with the world. May it spark new ideas for the future.
Continue reading “Reachy The Open Source Robot Says Bonjour” →
Intel’s CEO [Brian Krzanich] stopped by the Re/Code conference to announce Jimmy, the first robot from the 21st Century Robot project. The project is the brainchild of [Brian David Johnson], Intel’s resident futurist. We love the project’s manifesto:
Robot Is: Imagined first. Easy to build. Completely open source. Fiercely social. Intentionally iterative. Filled with humanity and dreams. Thinking for her/him/itself.
Jimmy may not be all those things yet, but he definitely is exciting. For starters, he wasn’t built in some secret lab at Intel HQ. Much of Jimmy’s construction took place at Trossen Robotics, a name well known to Hackaday. [Matt] and [Andrew] at Trossen describe all the details in their video down past the break.
This version of Jimmy is a research robot, which mean’s he’s not going to come cheap. Jimmy sports an Intel i5 NUC motherboard, 20 Dynamixel servos, a 5052 aluminum frame and a host of sensors. A 4S 14.8v 4000mAh LiPo battery will power Jimmy for 30 to 60 minutes between charges, so be sure to budget for a few spare packs. The most striking aspect of Jimmy is his 3D printed shell. The 21st Century Robot Project gave him large, friendly eyes and features, which will definitely help with the social aspect of their goals.
Jimmy is all about open source. He can run two flavors of Linux: Ubuntu 14.04 LTS or a custom version of Yocto Pokey. There is a lot to be said for running and developing on the same hardware. No specialized toolchains for cross compiling, no NFS shares to move binaries around. If you need to make a change, you can plug a monitor (or launch an VNC session) and do everything with Jimmy’s on-board computer. Jimmy’s software stack is based upon the DARwIn OP platform, and a ROS port is in the works.
We’re excited about Jimmy, but at $16,000 USD, he’s a bit outside our budget. Thankfully a smaller consumer version of Jimmy will soon be available for around 1/10th the cost.
Continue reading “Meet Jimmy: An Open Source Biped Robot From Intel” →