Don’t DIY This Surgical Robot At Home

January 9, 2020 by 11 Comments

The LVL1 Hackerspace in Louisville hosted a hackathon for useless and impractical devices a couple of years ago and this makeshift Duh-Vinci Surgical Robot was one of the “successful” results. While it’s not necessarily a project that should ever be used for its intended purpose, its miniature setup is certainly an interesting one.

The project builds on top of the MeArm Open Source Robot and a camera controlled by a Blynk board. Servos are wired into the base of each of the robotic arms for freedom in rotating. A separate microcontroller is used for the motor controllers for the arms and for the camera, partially due to the current draw for the camera power supply. The remote control system runs on an Android tablet and is used to control each of the arms.

The ESP32-Cam supplied video input is configured as a RTSP stream. As for the operation, while the movements are jerky and the range of dexterity limited, the robot is technically able to handle the sharps. Its final setup looks a bit like a deranged game of Hungry Hungry Hippos meets Operation and definitely not something to be making its way to surgical tables anytime soon.

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It Turns Out, Robots Need Tough Love Too

January 8, 2020 by 5 Comments

Showing robots adversarial behavior may be the key to improving their performance, according to a study conducted by the University of Southern California. While a generative adversarial network (GAN), where two neural networks compete in a game, has been demonstrated, this is the first time adversarial human users have been used in a learning effort.

The report was presented at the International Conference on Intelligent Robots and Systems, describing the experiment in which reinforcement learning was used to train robotic systems to create a general purpose system. For most robots, a huge amount of training data is necessary in order to manipulate objects in a human-like way.

A line of research that has been successful in overcoming this problem is having a “human in the loop”, in which a human provides feedback to the system in regards to its abilities. Most algorithms have assumed a cooperating human assistant, but by acting against the system the robot may be more inclined to develop robustness towards real world complexities.

The experiment that was conducted involved a robot attempting to grasp an object in a computer simulation. The human observer observes the simulated grasp and attempts to snatch the object away from the robot if the grasp is successful. This helps the robot discern weak and firm grasps, a crazy idea from the researchers that managed to work. The system trained with the adversary rejected unstable grasps, quickly learning robust grasps for different objects.

Experiments like these can test the assumptions made in the learning task for robotic applications, leading to better stress-tested systems more inclined to work in real-world situations. Take a look at the interview in the video below the break.

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OpenDog: Adding Force Sensitive Feet

January 4, 2020 by 16 Comments

[James Bruton] OpenDog remains one of the most impressive home-built robotics projects we’ve seen here on Hackaday, and it’s a gift that just keeps on giving. This time he’s working on adding force sensing capabilities to OpenDog’s legs to allow for more dynamic movement control.

The actuators in the legs are three-phase outrunner motors that drive ball-screws via a belt. This configuration is non-backdrivable, meaning the legs cannot be moved when an external force is, which could lead to mechanical failures. He as tested other backdrivable leg configurations with other robots, but did not want to rebuild OpenDog completely. The solution [James] went with is a redesigned foot with an inbuilt switch, to confirm that the foot is touching the ground, and a load cell attached in the middle of the bottom leg segment. The load cell is bolted rigidly onto the leg segment, which allows it to sense when the leg is carrying load, without damaging the load cell itself.

Unfortunately all the serial ports on OpenDog’s main Teensy 3.6 controller are already used, so he converted the signal from the load cell to PWM, to allow it to be read by a normal GPIO pin. This works well in isolation, but when [James] switches on the motors, the PWM signal from the load sensor gets flooded by interference, making it unreadable. To solve this problem, he wants to implement a CAN bus, which will allow for more inputs and outputs and hopefully solve the interference problem. However, [James] has no experience with the CAN protocol, so learning to use it is going to be a project on its own.

OpenDog is turning into a very lengthy, time-consuming project, [James] says that the lessons learned from it have been invaluable for a number of other projects. This is something to keep in mind with everything we tackle. Choose projects were the experience gained and/or relationships developed are worth it on their own, even when the project fails in a conventional sense. This way you can never really lose.

A Soft Robotic Insect That Survives The Fly Swatter

December 31, 2019 by 7 Comments

Swarms of robotic insects incapable of being swatted away may no longer be the product of science fiction and Black Mirror episodes. A team from EPFL’s School of Engineering has developed an insect propelled at 3 cm/s, dubbed the DEAnsect.

What makes this robot unique is its exceptional robustness. Two versions of the robot were initially developed, one tethered with ultra-thin wires capable of being squashed with a shoe without impacting its functions and the second fully wireless and autonomous. The robot weighs less than 1 gram and is equipped with a microcontroller and photodiodes to recognize black and white patterns.

The insect is named for its dielectric elastomer actuators (DEAs), an artificial muscle that propels it with vibrations and enables it to move lightly and quickly.

The DEAs are made of an elastomer membrane wedged between soft electrodes that are attracted to each other when a voltage is applied, compressing the membrane. The membrane returns to its original shape when the voltage is turned off. Movement is generated by switching the voltage on and off over 400 times per second. The team reduced the thickness of the membranes and developed soft, highly conductive electrodes only several molecules thick using nanofabrication techniques. They plan on fitting even more sensors and emitters to allow the insects to communicate directly with one another for greater swarm-like activity.

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Bend It Like Bhoite: Circuit Sculptures Shatter The Bounds Of Flatland

December 27, 2019 by 5 Comments

As electronics hobbyists, we live in a somewhat two-dimensional world. Our craft is so centered around the printed circuit board that our design tools are specifically geared to spit out files tailored to the board house, who can then ship us a study in fiberglass and copper. We daub on flux and solder, add components, apply heat, and like magic, our circuits come to life, all within a few millimeters above and below the PCB.

Breaking out of this self-imposed Flatland can be therapeutic. At least that’s how Mohit Bhoite sees his free-form circuit sculptures, which he spoke about at length at the Hackaday Superconference this year. By way of disclosure, I have to admit to being a longtime fan of Mohit’s work, both at his day job as a designer at Particle, and with his spare time hobby of creating sculptures from electronic components and brass wire which can be followed on his Twitter feed. He ended up joining us for a circuit sculpture Hack Chat just before heading to Supercon, too, so not only was I looking forward to meeting him, I was sure his talk would reveal the secrets of his art and give me the inspiration to start doing some of my own. I wasn’t disappointed on either score.

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Quadruped Robot Disguises Itself As A Ball

December 23, 2019 by 12 Comments

When the Skynet baseball bot swarms attack, we’ll be throwing [Carl Bugeja] some dirty looks for getting them started. He’s been working on 4B, a little quadruped robot that can transform itself into a sphere almost perfectly.

Before [Carl] was distracted by the wonders of PCB actuators more than a year ago, he started working on this little guy. He finally found some time to get it moving on its own, and the preliminary results look promising to say the least. Inside the 6 cm sphere is a total of 12 servos, 3 for each leg. All of the mechanical parts were 3D printed in nylon on an SLS machine, and the custom PCB has a BLE microcontroller module, an IMU and IR proximity sensors onboard. Everything is open source with all the files available on the Hackaday.io project page.

The microcontroller runs a full inverse kinematic model, so only the desired tip and base coordinate for each leg is input and the servo angles are automatically calculated. Ultimately [Carl] aims to have the robot both walking and rolling controllably. So far he’s achieved some degree of success in both, but it still needs some work (see the videos below. We’re eager to see what the future holds for this delightfully creepy bot.

Walking robots are always an interesting challenge. For more of our future overlords, check out this adorable little cat and this truly terrifying strandbeest.

Super Easy Small Robot Wheels

December 19, 2019 by 17 Comments

Anyone who has delved into DIY wheels knows that they are a trickier than it may seem, especially if the wheels aren’t just for show and need to provide things like decent traction and durability. 3D printers have helped a lot, but they’re not a cure-all.

Check out how [Robert K.] makes wheels from segments of automotive silicone hose, which are constructed with fibers embedded within them for durability and structure. Not only are these hoses easily sourced, but the silicone makes a great wheel surface and the hoses themselves are highly durable. He uses a 3D printed jig to cut a slice of hose that press-fits perfectly onto a 3D printed hub. [Robert] finds that a 28 mm hose pulled over a 35 mm diameter wheel is a perfect fit.

These wheels are for a Beetleweight class combat robot, which are limited to three pounds (1.36 kg) or less. You can see some video of [Robert]’s previous Beetleweight robot named ‘Bourbon’, and we have featured what goes into the even-smaller Antweight class (one pound or less) in the past.