Robots Collaborate To Localize Themselves Precisely

August 26, 2024 by Lewin Day 3 Comments

Here’s the thing about robots. It’s hard for them to figure out where to go or what they should be doing if they don’t know where they are. Giving them some method of localization is key to their usefulness in almost any task you can imagine. To that end, [Guy Elmakis], [Matan Coronel] and [David Zarrouk] have been working on methods for pairs of robots to help each other in this regard.

As per the research paper, the idea is to perform real-time 3D localization between two robots in a given location. The basic idea is that the robots take turns moving. While one robot moves, the other effectively acts as a landmark. The robots are equipped with inertial measurement units and cameras in a turret, which they use to track each other and their own movements. Each robot is equipped with a Raspberry Pi 4 for processing image data and computing positions, and the two robots communicate via Bluetooth to coordinate their efforts.

It’s an interesting technique that could have some real applications in swarm robotics, and in operations in areas where satellite navigation and other typical localization techniques are not practical. If you’re looking for more information, you can find the paper here. We’ve seen some other neat localization techniques for small robots before, too. Video after the break.

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Supercon 2023: Soft Actuators As Assistive Tech

August 21, 2024 by Tom Nardi 1 Comment

When we think of assistive prostheses or braces, we often think of hard and rigid contraptions. After all, it wasn’t that long ago that prosthetic limbs were still being made out of wood. Even devices made of more modern materials tend to have a robotic quality that inevitably limits their dexterity. However, advancements in soft robotics could allow for assistive devices that more closely mimic their organic counterparts.

At Supercon 2023, Benedetta Lia Mandelli and Emilio Sordi presented their work in developing soft actuator orthosis — specifically, a brace that can help tetraplegics with limited finger and thumb control. Individuals with certain spinal cord injuries can move their arms and wrists but are unable to grasp objects.

Existing braces can help restore this ability, but they are heavy and limited by the fact that the wearer needs to hold their wrist in a specific position to keep pressure on the mechanism. By replacing the rigid linkage used in the traditional orthosis, the experience of using the device is improved in many ways.

Not only is it lighter and more comfortable to wear, but the grip strength can also be more easily adjusted. The most important advancement however is how the user operates the device.

Like the more traditional designs, the wearer controls the grip through the position of their wrist. But the key difference with the soft actuator version is that the user doesn’t need to maintain that wrist position to keep the grip engaged. Once the inertial measurement units (IMUs) have detected the user has put their wrist into the proper position, the electronics maintain the pressure inside the actuator until commanded otherwise. This means that the user can freely move their wrist after gripping an object without inadvertently dropping it.

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Achieving Human Level Competitive Robot Table Tennis

August 11, 2024 by Maya Posch 12 Comments

A team at Google has spent a lot of time recently playing table tennis, purportedly only for science. Their goal was to see whether they could construct a robot which would not only play table tennis, but even keep up with practiced human players. In the paper available on ArXiv, they detail what it took to make it happen. The team also set up a site with a simplified explanation and some videos of the robot in action.

Table tennis robot vs human match outcomes. B is beginner, I is intermediate, A is advanced. (Credit: Google)

In the end, it took twenty motion-capture cameras, a pair of 125 FPS cameras, a 6 DOF robot on two linear rails, a special table tennis paddle, and a very large annotated dataset to train multiple convolutional neural networks (CNN) on to analyze the incoming visual data. This visual data was then combined with details like knowledge of the paddle’s position to churn out a value for use in the look-up table that forms the core of the high-level controller (HLC). This look-up table then decides which low-level controller (LLC) is picked to perform a certain action. In order to prevent the CNNs of the LLCs from ‘forgetting’ the training data, a total of 17 different CNNs were used, one per LLC.

The robot was tested with a range of players from a local table tennis club which made clear that while it could easily defeat beginners, intermediate players pose a serious threat. Advanced players completely demolished the table tennis robot. Clearly we do not have to fear our robotic table tennis playing overlords just yet, but the robot did receive praise for being an interesting practice partner. Continue reading “Achieving Human Level Competitive Robot Table Tennis” →

Inside The Mecanum Wheel

August 11, 2024 by Al Williams 5 Comments

If you make anything that moves, like a robot, you quickly realize that turning can be a pain. That’s why there are a number of designs for wheels that can go in different directions. One of the most common is the Mecanum wheel. [Jeremy] explains how they work by filming them from below on a transparent table. You can see the enlightening video below.

If you haven’t done anything with omni wheels before, it is disconcerting to see wheels rotating one way causing the vehicle to move at a right angle to the rotation. But this is very useful when you build robots or — as he shows at the start of the video — a forklift.

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Robot Arm Gives Kids The Roller Coaster Ride Of Their Lives

August 10, 2024 by Dan Maloney 60 Comments

Unfortunately, [Dave Niewinski]’s kids are still too little to go on a real roller coaster. But they’re certainly big enough to be tossed around by this giant robot arm roller coaster simulator.

As to the question of why [Dave] has a Kuka KR 150 robot in his house, we prefer to leave that unasked and move forward. And apparently, this isn’t his first attempt at using the industrial robot as a motion simulator. That attempt revealed a few structural problems with the attachment between the rider’s chair and the robot’s wrist. After redesigning the frame with stouter metal and adding a small form-factor gaming PC and a curved monitor in front of the seat, [Dave] was ready to figure out how to make the arm simulate the motions of a roller coaster.

Now, if you ever thought the world would be a better place if only we had a roller coaster database complete with 4k 60 fps video captured from real coasters, you’re in luck. CoasterStats not only exists, but it also includes six-axis accelerometer data from real rides of coasters across Europe. That gave [Dave] the raw data he needed, but getting it translated into robot motions that simulate the feeling of the ride was a bit tricky. [Dave] goes into the physics of it all in the video below, but suffice it to say that the result is pretty cool.

More after the break.

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Obscure Sci Fi Robots

August 7, 2024 by Al Williams 38 Comments

Even if you don’t like to build replicas of movie robots, you can often draw inspiration from cinema. Everyone knows Robby the Robot, Gort, and R2D2. But [Atomic Snack Bar] treats us to some lesser-known robots from movies in the 1930s, 40s, and 50s. While we are pretty up on movies, we have to admit that the video, which you can see below, has a few we didn’t know about.

The robots are mostly humanoid. The comedy vampire flick from the 1950s could have inspired Robby, who appeared four years later. The exception that proves the rule is the Twonky which was a TV set turned robot turned mind controller.

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Re-imagining Telepresence With Humanoid Robots And VR Headsets

July 30, 2024 by Donald Papp 20 Comments

Don’t let the name of the Open-TeleVision project fool you; it’s a framework for improving telepresence and making robotic teleoperation far more intuitive than it otherwise would be. It accomplishes this in part by taking advantage of the remarkable technology packed into modern VR headsets like the Apple Vision Pro and Meta Quest. There are loads of videos on the project page, many of which demonstrate successful teleoperation across vast distances.

Teleoperation of robotic effectors typically takes some getting used to. The camera views are unusual, the limbs don’t move the same way arms do, and intuitive human things like looking around to get a sense of where everything is don’t translate well.

A stereo camera with gimbal streaming to a VR headset complete with head tracking seems like a very hackable design.

To address this, researches provided a user with a robot-mounted, real-time stereo video stream (through which the user can turn their head and look around normally) as well as mapping arm and hand movements to humanoid robotic counterparts. This provides the feedback to manipulate objects and perform tasks in a much more intuitive way. In short, when our eyes, bodies, and hands look and work more or less the way we expect, it turns out it’s far easier to perform tasks.

The research paper goes into detail about the different systems, but in essence, a stereo depth and RGB camera is perched with a 3D printed gimbal atop a humanoid robot frame like the Unitree H1 equipped with high dexterity hands. A VR headset takes care of displaying a real-time stereoscopic video stream and letting the user look around. Hand tracking for the user is mapped to the dexterous hands and fingers. This lets a person look at, manipulate, and handle things without in-depth training. Perhaps slower and more clumsily than they would like, but in an intuitive way all the same.

Interested in taking a closer look? The GitHub repository has the necessary code, and while most of us will never be mashing ADD TO CART on something like the Unitree H1, the reference design for a stereo camera streaming to a VR headset and mirroring head tracking with a two-motor gimbal looks like the sort of thing that would be useful for a telepresence project or two.

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