The robot dog itself goes by the name of LOTP, for unspecified reasons, and was designed from the ground up in Fusion 360. A Teensy 3.5 is charged with running the show, managing control inputs and outputting the requisite instructions to the motor controllers to manage the walk cycle. Movement are issued via a custom RC controller. Thanks to an onboard IMU, the robotic platform is able to walk effectively and maintain its balance even on a sloping or moving platform.
[Limenitis] has built the robot with a modular platform to support different duties. Equitable modules include a sensor for detecting dangerous gases, a drone launching platform, and a lidar module. There’s also a provision for a camera which sends live video to the remote controller. [Limenitis] has that implemented with what appears to be a regular drone FPV camera, a straightforward way to get the job done.
It’s a fun build that looks ready to scamper around on adventures outside. Doing so with an FPV camera certainly looks fun, and we’ve seen similar gear equipped on other robot dogs, too.
Robot “dogs” are all the rage lately, but you probably haven’t seen one that can climb up a wall. Researchers in Korea have made one that can, assuming the wall is made out of a metal that a magnet can stick to at least. The robot, MARVEL or magnetically adhesive robot for versatile and expeditious locomotion, might be pressing its luck on acronyms, but it is pretty agile as you can see in the video below. Tests showed the robot walking on walls and ceilings. It can cross gaps and obstacles and can even handle a curved storage tank with paint and rust.
The robot weighs 8 kilograms (17.6 pounds), can carry 2 – 3 kg of payload, and operates without a tether. Each foot contains both an electropermanent magnet and magnetorheological elastomers. If you haven’t seen them before, an electropermanent magnet, or EPM, is a magnet that can be turned on or off electronically. The elastomer is a polymer containing ferromagnetic particles that can alter the material’s properties in response to a magnetic field.
EPMs have two parts. One part is a simple permanent magnet. The other is a soft core easily magnetized by a surrounding coil. If you magnetize the soft core to oppose the permanent magnet, the fields cancel out, effectively turning off the magnet. If you magnetize it the other way, it reinforces the field.
This is better than an electromagnet in this application because turning the magnet on or off only requires a brief pulse. If you want your robot to hang out on the ceiling with Spider Man indefinitely, you don’t have to worry about draining your batteries while keeping an electromagnet engaged.
What’s this? News about robot dogs comes out, and there’s no video of the bots busting a move on the dance floor? Nope — it looks like quadruped robots are finally going to work for real as “ground drones” are being deployed to patrol Cape Canaveral. Rather than the familiar and friendly Boston Dynamics “Big Dog” robot, the US Space Force went with Ghost Robotics Vision 60 Q-UGVs, or “quadruped unmanned ground vehicles.” The bots share the same basic layout as Big Dog but have a decidedly more robust appearance, and are somehow more sinister. The dogs are IP67-rated for all-weather use, and will be deployed for “damage assessments and patrols,” whatever that means. Although since this is the same dog that has had a gun mounted to it, we’d be careful not to stray too far from the tours at Kennedy Space Center.
Thanks to the efforts of a couple of large companies, many devoted hobbyists, and some dystopian science fiction, robot dogs have firmly entered the zeitgeist of our “living in the future” world. The quadrupedal platform, with its agility and low center of gravity, is perfect for navigating in the real world, where the terrain is rarely even and unexpected obstacles are to be expected.
The robot dog has been successful enough that there are commercially available — if prohibitively priced — dogs on the market, doing everything from inspecting factory processes and off-shore oil platforms to dancing for their dinner. All the publicity around robot dogs has fueled a crush of DIY and open-source versions, so that hobbyists can take advantage of what the platform has to offer. And as a result, the design of these dogs has converged somewhat, with elements that provide a common design language for these electromechanical pets.
Afreez Gan has been exploring the robot dog space for a while now, and his MiniPupper is generating some interest. He’ll stop by the Hack Chat to talk about MiniPupper specifically and the quadruped platform in general. We’ll talk about what it takes to build your own robot dog, what you can do with one once you’ve built it, and how these bots can play a part in STEM education. Along the way, we’ll touch on ROS, lidar, machine vision with OpenCV, and pretty much anything involved in the care and feeding of your newest electronic pal.
Not long ago, Boston Dynamics’ Spot finally went on sale, meaning the dog-like robot can now be purchased online. Previously it was available only to be leased by early adopters willing to pay to see what the robot had to offer. Pricing was tucked behind an NDA, and Spot could be only leased and not actually purchased — until now.
From a hobbyist’s perspective, Spot’s price is of course eye-watering; the cost of the accessories even more so. It would be perfectly understandable to ask what good is a robotic dog and what makes it worth such a cost?
From an industrial equipment point of view, the cost is perhaps less shocking. Maybe it’s a reminder that from an industrial and commercial perspective, the price of a thing matters mainly in relation to what kind of benefits it can bring, and what kind of price or savings can be hung on that.
Personally, I am a fan of the real thing, but dogs aren’t an option for all. Plus, robotic dogs are easier to train and don’t pee on your couch. If you are looking to adopt a robotic companion, Stanford Pupper might be a good place to start. It’s a new open source project from the Stanford Robotics Student group, a group of robotic hackers from Stanford University. This simple robotic quadruped looks pretty simple to build, but also looks like a great into to four-legged robots.
This is the first version of the design, but it looks pretty complete, built around a carbon fiber and 3D printed frame. The carbon fiber parts have to be cut out on a router, but you can order them pre-cut here, and you might be able to adapt it to easier materials. The Pupper is driven by twelve servos powered from a 5200 mAh 2S LiPo battery and a custom PCB that distributes the power. That means it could run autonomously.
Getting a legged robot to stay upright, especially a quadruped or biped, can be a challenging undertaking. To experiment with different approaches, [James Bruton] built robot dog test platform and is playing with “dynamic compliant simulated springs“, or in other words, using the motors to act as though they were springs and dampers..
When robotic legs are kept stiff, they tend to reduce the stability of the platform due to the sudden erratic movements of the robot, especially on uneven surfaces. With a back drivable joint arrangement, [James] is using limited holding current on the motor, and the position of the motor shaft is monitored using an encoder. When a leg experiences a resisting force, with will have some “give” and then the motor will return it to it’s intended position more slowly. Using a IMU on top of the robot, it can detect when it start leaning to a side, and then temporarily soften the other side to balance the robot.
This is quite a common technique in legged robots, but [James] does an excellent job of explaining just how it works. He hopes to use the lessons learned from the test platform to improve or redesign his already impressive OpenDog.