One-Legged Robot Does The Hop

May 25, 2019 by Al Williams 19 Comments

At first, we thought this robot was like a rabbit until we realized rabbits have a 300% bonus in the leg department. SALTO — a robot from [Justin Yim], [Eric Wang], and [Ronald Fearing] only has one leg but gets around quite well hopping from place to place. If you can’t picture it, the video below will make it very obvious.

According to the paper about SALTO, existing hopping robots require external sensors and often are tethered. SALTO is self-contained. The robot weighs a tenth of a kilogram and takes its name from the word saltatorial (adapted for leaping ) which itself comes from the Latin saltare which means to jump or leap.

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Robot Hummingbird Imitates Nature

May 12, 2019 by Al Williams 9 Comments

Purdue’s Bio-Robotics lab has been working on a robotic hummingbird and, as you can see in the videos below, have had a lot of success. What’s more, is they’ve shared that success on GitHub. If you want to make a flapping-winged robot, this is definitely where you start.

If you’ve ever watched a hummingbird, you know their flight capability is nothing short of spectacular. The Purdue robot flies in a similar fashion (although on a tether to get both power and control information) and relies on each wing having its own motor. The motors not only propel the wings but also act as sensors. For example, they can detect if a wing is damaged, has made contact with something, or has changed performance due to atmospheric conditions.

In addition to the tethered control system, the hummingbird requires a motion capture sensor external to itself and some machine learning. Researchers note that there is sufficient payload capacity to put batteries onboard and they would also need additional sensors to accomplish totally free flight. It is amazing when you realize that a real hummingbird manages all this with a little bitty brain.

The published code is in Python and is part of three presentations later this month at a technical conference (the IEEE International Conference on Robotics and Automation). If you don’t want to wait on the paper, there’s a post on IEEE Spectrum about the robotic beast, available now and that article contains preprint versions of the papers. The Python code does require a bit to run, so expect a significant flight computer.

The last hummingbird bot we saw was a spy. We’ve also seen robots that were like bees — sort of.

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Battlebots To The Skies!

May 1, 2019 by Bryan Cockfield 10 Comments

If you’re too young to remember Battlebots on the television, there are two things that you should know. First is that there are plenty of highlights of this epic robot battle royale on YouTube, and the second is that now there’s an even better version with drones instead of robots merely confined to land. It’s called DroneClash 2019, and it looks like it was amazing.

Not only were the robots set up in a box and asked to battle each other, they first had to navigate down a corridor with anti-drone measures. The drones have to make it through and into a battle royale in the final room. If this wasn’t good enough, the event was opened by a prince of the Netherlands and is put on by a university.

This is an annual event to push the state of the art in drone and anti-drone tech, but we’d be happy to see it optioned for a TV show. If it doesn’t, you might be satisfied with a giant human-driven robot competition from a while back, or maybe just head down the rabbit hole of old Battlebots clips.

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Televox: The Past’s Robot Of The Future

April 12, 2019 by Al Williams 23 Comments

When I read old books, I like to look for predictions of the future. Since we are living in that future, it is fun to see how they did. Case in point: I have a copy of “The New Wonder Book of Knowledge”, an anthology from 1941. This was the kind of book you wanted before there was a Wikipedia to read in your spare time. There are articles about how coal is mined, how phonographs work, and the inner workings of a beehive. Not the kind of book you’d grab to look up something specific, but a great book to read if you just want to learn something interesting. In it there are a few articles about technology that seemed ready to take us to the future. One of those is the Televox — a robot from Westinghouse poised to usher in an age of home and industrial mechanical servants. Robots in 1941? Actually, Televox came into being in 1927.

If you were writing about the future in 2001, you might have pictured city sidewalks congested with commuters riding Segways. After all, in 2001, we were told that something was about to hit the market that would “change everything.” It had a known inventor, Dean Kamen, and a significant venture capitalist behind it. While it has found a few niche markets, it isn’t the billion dollar personal transportation juggernaut that was predicted.

But technology is like that. Sometimes things seem poised for greatness and disappear — bubble memory comes to mind. Sometimes things have a few years of success and get replaced by something better. Fax machines or floppy drives, for example. The Televox was a glimpse of what was to come, but not in any way that people imagined in 1941. Continue reading “Televox: The Past’s Robot Of The Future” →

ROS Gets Quick Sensor Debugging In The Terminal

March 31, 2019 by Lewin Day 6 Comments

Sensors are critical in robotics. A robot relies on its sensor package to perform its programmed duties. If sensors are damaged or non-functional, the robot can perform unpredictably, or even fail entirely. [Dheera Venkatraman] has been working to make debugging sensor issues easier with the rosshow package for Robot Operating System.

Normally, if you want to be certain a camera feed is working on a robot, normally you’d have to connect a monitor and other peripherals, check manually, then put everything away again when you’re finished. [Dheera] considered this was altogether too much of a pain for basic sensor checks.

Instead, rosshow uses the power of SSH to speed things along. Log in to the robot, fire off a few command line instructions, and rosshow will start displaying sensor data in the terminal on your remote machine. It’s achieved through the use of Unicode Braille art in the terminal. Sure, you won’t get a full-resolution feed from your high-definition camera, and the display from the laser scanner isn’t exactly perfect. But it’s enough to provide an instant verification that sensors are connected and working, and will speed up those routine is-it-connected checks by an order of magnitude.

Robot Operating System is a particularly useful platform if you’re thinking about the software platform for your next build. If you do put something together, be sure to let us know.

A Pet Robot, Just Like Boston Dynamics Makes

March 30, 2019 by Brian Benchoff 13 Comments

Every few months or so, a new video from Boston Dynamics will make the rounds on the Internet. This is their advertising, because unless the military starts buying mechanical mules, Boston Dynamics is going to be out of business pretty soon. You’ll see robots being kicked down the stairs, robots walking through doors, and robots acting like dogs. If a hundred or so highly skilled and highly educated roboticists, technologists, and other experts can put together a walking dog robot in a decade, obviously one person can cut through the cruft and build one in a basement. That’s what [Misha] is doing. It’s the Dizzy Wolf, a robotic wolf, or dog, or cat, we don’t actually know because there’s no fur (or head) yet. But it is interesting.

The key component for any quadruped robot is a high-torque, low-noise servo motor. This isn’t a regular ‘ol brushless motor, and for this application nine gram servos go in the trash. This means custom made motors, or DizzyMotors. You’re looking at a big brushless motor with a planetary gearset, all squished into something that could actually fit into the joint of a robotic wolf’s leg.

There’s a driver for these motors, strangely not called the DizzyDriver, that turns a BLDC into a direct drive servo motor. It is effectively a smart servo, that will move to a specific rotation, receive commands over RS-485, and write back the angular position. It also applies constant torque. Of course, there is a video of the DizzyMotor and servo driver below.

Building a robotic dog that will walk around the house is one of the hardest engineering challenges out there. You’ve got fairly crazy kinematics, you’ll need to think about the strength of the frame, control systems, and eventually how to fit everything in a compact design. This project is hitting all the marks, and we can’t wait to see the Dizzy Wolf do a backflip or chase a ball.

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This Force Controlled Robot Gripper Is Less Likely To Break Stuff

March 25, 2019 by Lewin Day No comments

While robotic arms can handle a wide variety of tasks, the specific job at hand will have a major influence on the type of end effector used. For sorting ferromagnetic parts an electromagnet might be enough, while for more accurate location a mechanical gripper could be employed. If you’re working with particularly delicate objects or in concert with human beings, it may be desired to have a force controlled gripper to avoid damage. [James Bruton] has been whipping up a design of his own for just this purpose.

The basic gripper is 3D printed, with 3 fingers consisting of two joints each. Retraction of each finger is courtesy of bungee cord, while extension is via a servo attached to the finger through a spring. The position of each finger is measured with a resistive flex sensor. An Arduino Uno is employed to run the servos and read the attached sensors.

As force is applied by the servo, the spring begins to stretch. This leads to a greater difference between the servo position and the finger position as the applied force increases. By calculating this difference, it’s possible to determine the force applied by the fingers. This can then be used to limit the applied force of the gripper, to avoid breaking delicate objects or crushing soft, fleshy humans.

[James] notes that there are some drawbacks to the current design. The force required to move the fingers is inconsistent along their travel, and this interferes somewhat with accurate measurement. Overall though it’s a solid proof of concept and a good base for further revisions. Files are on Github for those who wish to tinker at home.

Being aware of the forces applied in mechanical settings can be key to getting good results. We’ve even seen arbor presses modified for just such a purpose. Video after the break.

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