Surgery Robot Is A Real Cut Up

May 7, 2020 by Adam Fabio 23 Comments

A robot that performs surgery is a serious thing. One bug in the control system could end with disaster. Unless of course, you’re [Michael Reeves], in which case disaster is all part of the fun. (Video, embedded below.)

Taking inspiration from The da Vinci Surgical System, [Michael] set out to build a system that was faster, while still maintaining precision. He created a belt drive gantry system, not unlike many 3D printers, laser cutters, or woodworking CNC machines. Machines like this often use stepper motors. [Michael] decided to go with [Oskar Weigl’s] ODrive and brushless motors instead. The ODrive is on open source controller which turns off the shelf brushless motors — such as those found in R/C planes or hoverboards, into precision industrial servos. Sound familiar? ODrive was an entrant in the 2016 Hackaday Prize. [Michael] was even able to do away the ubiquitous limit switch by monitoring current draw with the ODrive.

It all adds up to a serious build. But this is [Michael “laser eye” Reeves] after all. The video is meant to be entertaining, with a hidden payload of education and inspiration. The fun starts when he arms the robot with a giant kitchen knife and performs “surgery” on a pineapple. If you want to know what happens when mannequins and fake blood enter the picture, then watch the video after the break.

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This Animatronic Mouth Mimics Speech With Servos

April 30, 2020 by Dan Maloney 12 Comments

Of the 43 muscles that comprise the human face, only a few are actually important to speaking. And yet replicating the movements of the mouth by mechanical means always seems to end up only partly convincing. Servos and linkages can only approximate the complex motions the lips, cheeks, jaw, and tongue are capable of. Still, there are animatronics out there that make a good go at the job, of which this somewhat creepy mechanical mouth is a fine example.

Why exactly [Will Cogley] felt the need to build a mechanical maw with terrifying and fairly realistic fangs is anyone’s guess. Recalling his lifelike disembodied animatronic heart build, it just seems like he pursues these builds for the challenge of it all. But if you thought the linkages of the heart were complex, wait till you see what’s needed to make this mouth move realistically. [Will] has stuffed this pie hole with nine servos, all working together to move the jaw up and down, push and pull the corners of the mouth, raise and lower the lips, and bounce the tongue around.

It all seems very complex, but [Will] explains that he actually simplified the mechanical design to concentrate more on the software side, which is a text-to-speech movement translator. Text input is translated to phonemes, each of which corresponds to a mouth shape that the servos can create. It’s pretty realistic although somewhat disturbing, especially when the mouth is placed in an otherwise cuddly stuffed bear that serenades you from the nightstand; check out the second video below for that.

[Will] has been doing a bang-up job on animatronics lately, from 3D-printed eyeballs to dexterous mechatronic hands. We’re looking forward to whatever he comes up with next — we think.

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Cable Driven Robotic Joint

April 26, 2020 by Danie Conradie 14 Comments

Even the oldest of mechanisms remain useful in modern technology. [Skyentific] has been messing with robotic joints for quite a while, and demonstrated an interesting way to use a pulley system in a robotic joint with quite a bit of mechanical advantage and zero backlash.

Inspired by the LIMS2-AMBIDEX robotic arm, the mechanism is effectively two counteracting sets of pulley, running of the same cable reel, with rollers allowing them to act around the bend of the joint. Increasing the mechanical advantage of the joint is simply a matter of adding pulleys and rollers. If this is difficult to envision, don’t work as [Skyentific] does an excellent job of explaining how the mechanism works using CAD models in the video below.

The mechanism is back drivable, which would allow it to be used for dynamic control using a motor with an encoder for position feedback. This could be a useful feature in walking robots that need to respond to dynamically changing terrain to stay upright, or in arms that need to push or pull without damaging anything. With properly tensioned cables, there is no backlash in the mechanism. Unfortunately cables can stretch over time, so it is something that needs to be considered when using this in a project.

Pulley systems have been with us for a very long time, and remain a very handy tool to have in your mechanical toolbox. A similar arrangement is used in the Da Vinci surgical robots to control their tiny manipulators. It would also be interesting to see this used in the already impressive robots of [James Bruton]. Continue reading “Cable Driven Robotic Joint” →

Automate Your Xbox

April 24, 2020 by Mike Szczys 9 Comments

First the robots took our jobs, then they came for our video games. This dystopian future is brought to you by [Little French Kev] who designed this adorable 3D-printed robot arm to interface with an Xbox One controller joystick. He shows it off in the video after the break, controlling a ball-balancing physics demonstration written in Unity.

Hats off to him on the quality of the design. There are two parts that nestle the knob of the thumbstick from either side. He mates those pieces with each other using screws, firmly hugging the stick. Bearings are used at the joints for smooth action of the two servo motors that control the arm. The base of the robotic appendage is zip-tied to the controller itself.

The build targets experimentation with machine learning. Since the computer can control the arm via an Arduino, and the computer has access to metrics of what’s happening in the virtual environment, it’s a perfect for training a neural network. Are you thinking what we’re thinking? This is the beginning of hardware speed-running your favorite video games like [SethBling] did for Super Mario World half a decade ago. It will be more impressive since this would be done by automating the mechanical bit of the controller rather than operating purely in the software realm. You’ll just need to do your own hack to implement button control.

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Underwater Crawling Soft Robot Stays In Shape

April 23, 2020 by Moritz v. Sivers 9 Comments

When you think of robots that were modeled after animals, a brittle star is probably not the first species that comes to mind. Still, this is the animal that inspired [Zach J. Patterson] and his research colleagues from Carnegie Mellon University for their underwater crawling robot PATRICK.

PATRICK is a soft robot made from molded silicone. Each of his five limbs contains several shape memory alloy (SMA) springs which can be contracted through Joule heating thereby causing the limbs to bend. The robot’s control board is sending and receiving commands via Bluetooth Low Energy from a nearby computer. To control PATRICK’s motion the researchers constructed a closed-loop system where an offboard OpenCV based camera system is constantly tracking the robot. As shown in the video below with an average velocity of 1 cm/s, PATRICK’s movement is a bit sluggish but the system is supposedly very robust against uncertainties in the environment.

In the future [Zach J. Patterson et al.] would like to improve their design by giving the robot the ability to grasp objects. Ultimately, also the offboard camera should be replaced with onboard sensors so that PATRICK can navigate autonomously.

Soft robots like artificial jellyfish are especially useful underwater and sometimes almost cross the boundary to organic life.

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Get Back Out There, Robotically

April 18, 2020 by Bryan Cockfield 8 Comments

When interacting with reality at a distance is the best course of action, we turn to robots. Whether that’s exploring the surface of Venus, the depths of the ocean, or (for the time being) society at large, it’s often better to put a robot out there than an actual human being. We can’t all send robots to other planets, but we can easily get them in various other places with telepresence robots.

This tiny telepresence robot comes to us from [Ross] at [Crafty Robot] who is using their small Smartibot platform as a basis for this tiny robot. The smartibot drives an easily-created cardboard platform, complete with wheels, and trucks around a smartphone of some sort which handles the video and network capabilities. The robot can be viewed and controlled from any other computer using a suite of web applications that can be found on the project page.

The Smartibot platform is an inexpensive platform that we’ve seen do other things like drive an airship, and the creators are hoping that as many people as possible can get some use out of this quick-and-easy telepresence robot if they really need something like this right now. The kit seems like it would be useful for a lot of other fun projects as well.

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The Drone That Flies In Any Orientation

April 14, 2020 by Danie Conradie 8 Comments

Modern radio-controlled multi-rotor drone can be incredibly agile, but can only make orientation changes around the yaw axis while remaining in approximately the same position. Researchers at ETH Zurich have again built and tested multirotor with controllable motion six degrees of freedom, this time dramatically improving efficiency.

We covered a similar design from ETH Zurich previously which was hexacopter with arms with limited rotation. This new design is also a hexacopter, but with 2 coaxial motors on each rotating arm. Each arm has an increased range of rotation over the previous design, beyond 360 degrees. With the range of rotation and the very complex control system, the drone can efficiently fly in any orientation, while still being able to apply effective torque or linear force in any direction. This opens up a lot of possibilities for tasks that drones can perform, like close-up industrial inspection, using tools or pulling cables while keeping the rotors clear.

The arms do have a limited amount of rotation before winding the motor cable tight, but the control system keeps track of this and can unwind during or after movement. See the video after the break to see it in action. The complete scientific paper is not light reading, but definitely interesting. We’re looking forward to seeing if and when these type designs get used in real-world applications.

There are without a doubt a lot of drones in our future, and probably the most successful project to date is the Zipline fixed-wing drones in Rwanda and Ghana, which have made over 35000 deliveries of emergency medical supplies since 2016.

Thanks [Qes] for the tip!

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