Robot: Will Draw For Food

September 14, 2022 by Al Williams 2 Comments

Biological systems often figure out the best ways to get what they need to survive. Now a robot created by researchers at Worcester Polytechnic Institute, Imperial College London, and the University of Illinois Urbana Champaign can make the same claim. The robot operates in front of a plate that has electrical terminals on one end and various obstacles between those terminals and the robot.

The robot can pick up and rearrange some of the items on the plate and then draws paths to the terminals using conductive ink. The effect is the robot gets to “eat” if it solves the connection puzzle.

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An image of the track system of the Calico wearable on top of a garment. Different possible positions of the device (elbow, shoulder, etc) are shown by red dots overlayed on the top of the image.

The Calico Wearable Rides The Rails

September 14, 2022 by Navarre Bartz 12 Comments

If you’re feeling underwhelmed by yet another smartwatch announcement, then researchers at the University of Maryland may have just the wearable for you. Instead of just tracking your movement from one spot, Calico winds around you like a cartoon sidekick.

Using a “railway system,”(PDF) the Calico can travel around a garment to get better telemetry than if it were shackled to a wrist. By moving around the body, the robot can track exercise, teach dance moves, or take up-close heart measurements. Tracks can be magnetically linked across garments, and Calico can use different movement patterns to communicate information to the user.

This two-wheeled robot that rides the rails is built around a custom PCB with a MDBT42Q microcontroller for a brain which lets it communicate with a smartphone over Bluetooth Low Energy. Location is monitored by small magnets embedded in the silicone and plastic living hinge track, and it can use location as a way to provide “ambient visual feedback.”

The researchers even designed a friendly cover for the robot with googly eyes so that the device feels more personable. We think animated wearables could really take off since everyone loves cute animal companions, assuming they don’t fall into the uncanny valley.

If you love unusual wearables as much as we do, be sure to check out Wearable Sensors on Your Skin and the Wearable Cone of Silence.

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A Crowned Pulley Keeps Robot’s Treads On Track

September 11, 2022 by Donald Papp 20 Comments

[Angus] at Maker’s Muse recently created a new and tiny antweight combat robot (video, embedded below) and it has some wonderfully clever design elements we’d like to highlight. In particular: how to keep a tracked robot’s wheel belt where it belongs, and prevent it from slipping or becoming dislodged. In a way, this problem was elegantly solved during the era of the steam engine and industrial revolution. The solution? A crowned pulley.

Silicone bracelet and crowned pulley result in a self-centering belt with a minimum of parts.

A crowned pulley is a way of automatically keeping a flat belt centered by having a slight hump in the center of the pulley, which tapers off on either side. Back when steam engines ran everything, spinning axles along the ceiling transferred their power to machinery on the shop floor via flat belts on pulleys. Crowned pulleys kept those flat belts centered without any need for rims or similar additions.

The reason this worked so well for [Angus]’s robot is partly its simplicity, and partly the fact that it works fantastically with the silicone wrist bracelets he uses as treads. These bracelets are like thick rubber bands, and make excellent wheel substitutes. They have great grip, are cheap and plentiful, and work beautifully with crowned pulleys as the hubs. It’s a great solution for a tiny robot, and you can how it self-centers in the image here.

Antweight robots are limited to 150 grams which means every bit counts, and that constraint leads to some pretty inventive design choices. For example, [Angus]’s new robot also has a clever lifter mechanism that uses a 4-bar linkage designed to lever opponents up using only a single motor for power. Watch [Angus] explain and demonstrate everything in his usual concise and clear manner in the video, embedded below.

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Rolling Sphere Robotic Arm Seems Serpentine

September 1, 2022 by Danie Conradie 9 Comments

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.

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Hackaday Prize 2022: A Sun-Chasing Robot

August 31, 2022 by Lewin Day 5 Comments

There’s plenty of power to be had from the sun, but you need to be out of the shade to receive it. [Dennis] built a robot by the name of Sun Chaser that has the smarts to go where the sun is shining.

Sun Chaser is essentially a robotic solar panel, tasked with filling up its batteries as much as possible. It can then be used as a power supply for campsites or other remote areas, and used to charge devices as required.

A Raspberry Pi runs the show, paired with a Squid motor controller to run the drive system. Sun Chaser has a motorized solar panel onboard which can track the sun for maximum output, with the aid of six photoresistors to guide the positioning. A camera is used to image the area around Sun Chaser, too, and processing is used to identify sunny regions which will provide the most energy.

Even outside of its useful applications, the idea of having a robot that can run around and keep itself juiced up is a fun one. Solar power gives a robot a greater sense of autonomy, after all. This author has experimented in this field to great enjoyment, too. Video after the break.

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Small Combat Robots Pack A Punch In Antweight Division

August 22, 2022 by Donald Papp 6 Comments

Two robots enter, one robot leaves! Combat robotics are a fantastic showcase of design and skill, but the mechanical contenders don’t have to be big, heavy, and expensive. There is an Antweight division for combat robots in which most contenders weigh a mere 150 grams, and [Harry Makes Things] shows off four participants for Antweight World Series (AWS) 64.

Clockwise: ReLoader, Shakma, Sad Ken, and HobGoblet antweight combat robots.

Each of them have very different designs, and there are plenty of photos as well as insightful details about what was done and how well it worked. That’s exactly the kind of detail we love to read about, so huge thanks to [Harry] for sharing!

In combat robotics, contenders generally maneuver their remote-controlled machines to pin or immobilize their opponent. This can happen as a result of damaging them to the point that they stop functioning, but it can also happen by rending them helpless by working some kind of mechanical advantage. Continue reading “Small Combat Robots Pack A Punch In Antweight Division” →

Mecanum-Wheeled Robot Chassis Takes Commands From PS4 Controller

August 19, 2022 by Lewin Day 1 Comment

Mecanum wheels are popular choices for everything from robots to baggage handling equipment in airports. Depending on their direction of rotation, they can generate forces in any planar direction, providing for great maneuverability. [ATOM] set about building just such a robot chassis, and learned plenty in the process.

The design is similar to those we’ve seen in the past. The robot has four mecanum wheels, each driven by its own motor. Depending on the direction of rotation of the various wheels, the robot can move forward, backwards, and even strafe left and right. Plus, it can effectively tank turn without excessive slippage thanks to the rollers on each wheel. An ESP32 serves as the brains of the ‘bot, allowing it to be readily remote controlled via a PS4 gamepad over Bluetooth.

If you’re looking to build a small robot chassis that’s great at moving about in tight, small spaces, this could be a great project to learn with. All the necessary parts are relatively easily available, and the PCB files can be had on GitHub.

If you like the idea of mecanum wheels but need something bigger, consider starting with a set of hoverboard wheel motors. Continue reading “Mecanum-Wheeled Robot Chassis Takes Commands From PS4 Controller” →