2022 FPV Contest: The LOTP Robot Dog

December 21, 2022 by Lewin Day 7 Comments

When you think of first person view (FPV) vehicles, aircraft might be what first comes to mind. However, [Limenitis Reducta] has brought a robot dog into the world, and plans to equip it for some FPV adventures.

LOTP pictured with various equippable modules.

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.

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Seriously, Don’t Buy This Mopping Robot

December 20, 2022 by Donald Papp 18 Comments

The original Roomba robotic vacuum cleaner led to loads of clones and lookalikes over the years, and one of them is the ALEE mopping “robot”. [Raymond] tears it down and reveals what’s inside. Turns out it contains mostly regret! Although it does host some design cleverness in its own way.

Technically the ALEE, which cost [Raymond] a cool $85 USD, is not a robot since it has no sensors. And unless a dragging a wet cloth pad kept moist by a crude drip reservoir counts as “mopping”, it’s not much of a mop, either.

This one-motor unit (and tiny battery) is responsible for both motion and direction control. There are no sensors.

There is one interesting aspect to this thing, and it’s to do with the drive system and direction control. The whole thing is driven by a single motor, and not a very powerful one. The center of the robot has a pair of wheels that are both driven at the same rate and speed, and the wheel assembly can pivot around its axis. That’s about it. There are not even any bump sensors of any kind.

So how does this thing move, let alone change direction to (poorly) emulate an original Roomba-like crisscross pattern? The control board appears to have one job: if the motor stalls, reverse direction. That, combined with the fact that the drive unit can pivot and the enclosure is dragging a wet rag, appears to be all the chaos that’s needed to turn bonking into a wall into an undefined direction change.

It’s not great performance, but it sure is some impressive cost-cutting. You can see it bonk around unimpressively in a short video, embedded below the page break.

Just to be clear, [Raymond] knows perfectly well what he’s in for when he obtains cheap tech items from overseas retailers for teardowns. The ALEE does have some mildly interesting secrets to share, but overall, it really wasn’t worth it. Sometimes cheap tech has hacker potential, but there’s no such potential here. Seriously, don’t buy this thing.

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Mini Cheetah Clone Teardown, By None Other Than Original Designer

December 19, 2022 by Donald Papp 21 Comments

[Ben Katz] designed the original MIT Mini Cheetah robot, which easily captured attention and imagination with its decidedly un-robotic movements and backflips. Not long after [Ben]’s masters thesis went online, clones of the actuators started to show up at overseas sellers, and a few months after that, clones of the whole robot. [Ben] recently had the opportunity to disassemble just such a clone by Dogotix and see what was inside.

Amusingly, one of the first things he noticed is that the “feet” are still just off-the-shelf squash balls, same as his original mini cheetah design. As for the rest of the leg, inside is a belt that goes past some tensioners, connecting the knee joint to an actuator in the shoulder.

As one may expect, these parts are subject to a fair bit of stress, so they have to be sturdy. This design allows for slender yet strong legs without putting an actuator in the knee joint, and you may recall we’ve seen a similar robot gain the ability to stand with the addition of a rigid brace.

It’s interesting to read [Ben]’s thoughts as he disassembles and photographs the unit, and you’ll have to read his post to catch them all. But in the meantime, why not take a moment to see how a neighbor’s curious sheep react to the robot in the video embedded below? The robot botches a backflip due to a low battery, but the sheep seem suitably impressed anyway.

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Robot Dog Has Animal Magnetism

December 18, 2022 by Al Williams 7 Comments

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.

Overall, an interesting robot. Most wall-climbing robots we’ve seen are pretty lightweight. We don’t see nearly as many that can have the feeling of clinging to the ceiling.

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Omniwhegs Are Awesome Times Two

December 14, 2022 by Elliot Williams 26 Comments

What’s the strangest wheel? The omniwheel. Unless you count whegs — “wheel legs” — as wheels. This research paper from Shanghai Technical University explores a mash-up of the two ideas, where the wheels roll as standard omniwheels until a servo on the axle unfurls them into their whegs configuration. The result? OmniWhegs!

The resulting vehicle is a bit of a departure from the original whegs concept, which used compliant mechanisms which passively balanced the force across the legs. Here, the omniwhegs are rigid and actually use a synchronization routine that you can see in the video embedded below.

If you can’t get enough omniwheels, you’re not alone. Here’s a rare three-wheeler, and here’s an omniwheel made of MDF. We haven’t seen enough whegs-based bots, but OutRunner is pretty astounding, and we think deserves a second look.

We’ve also seen wheels that convert to whegs before, but without the omni. And we don’t know if that one ever made it out of render-of-a-robot phase.

So kudos to the Shanghai team for taking the strangest possible wheels and actually building them!

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Simple Mod Lets Quadruped Robot Stand And Walk

November 19, 2022 by Donald Papp 9 Comments

When it comes to locomotion, robots don’t typically do more than one thing at a time. Walkers stick to walking, and rollers stick to rolling. However, this simple method of enabling a cheetah-style quadruped to stand and even walk a little is pretty clever.

With just a couple of rigid struts attached to the shins of the rear legs, it becomes possible for the robot to lever itself up into a stable standing position, and even shuffle around a bit. Not bad for a couple bolted-on bits with no moving parts!

The robot style will look pretty familiar to some of our readers. It does resemble Boston Dynamics’ Spot but it’s closer to the MIT Mini Cheetah, whose design and brushless motors made for eye-catching agility and speed. It has inspired not just countless DIY efforts, but also kits of parts from overseas sellers.

The image here should make it clear how it works, but take a moment to also watch the short video embedded just below the page break, and see the process in action from beginning to end.

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Robot Gets A Life-Sized Pokemon Costume For Halloween

November 12, 2022 by Lewin Day 3 Comments

Quadruped robots are everywhere now that companies like Boston Dynamics are shipping smaller models in big numbers. [Dave’s Armoury] had one such robot, and wanted to give it a Pokemon Halloween costume. Thus, the robot dog got a Jolteon costume that truly looks fantastic. (Video, embedded below.)

You would think that covering a quadruped robot in foam would ruin it, but somehow it didn’t stop it moving too badly at all.

The robot in question is a Unitree Go1, which [Dave] had on loan from InDro robotics. Thus, the costume couldn’t damage or majorly alter the robot in any way. Jolteon was chosen from the original 150 Pokemon as it had the right proportions to suit the robot, and its electric theme fitted [Dave’s] YouTube channel.

A 3D model of Jolteon was sourced online and modified to create a printable head for the robot application. Two 3D printers and 200 hours of printing time later, and [Dave] had all the parts he needed. Plenty of CA glue was used to join all the parts together with some finishing required to make sure seams and edges didn’t spoil the finish too much. Wood filler and spray paint were used to get the costume looking just like the real Pokemon. Continue reading “Robot Gets A Life-Sized Pokemon Costume For Halloween” →