ArrBot Is A Fast Way To Get Out Standing In A New Field Of Robotics

[Junglist] correctly points out that agricultural robotics is fast on its way to being the next big thing (TM) and presents his easy to build ArrBot platform so others can get hacking fast. 

The frame is built out of the same brackets and aluminum tubing used to add handrails to stairwells on buildings. Not only is this a fast way to do it, the set-up can be guaranteed to be sturdy since hand rails are often literally standing between life and death. The high ground clearance allows for all sorts of sensors and devices to be mounted while still being able to clear the plants below. 

For motion hub motors driven by an ODrive were re-purposed for the task. He explored turning the wheels as well, but it seems like  differential steer and casters works well for this set-up. ROS on an Nividia Jetson runs the show and deals with the various sensors such as a stereoscopic camera and IMU.

We’re excited to see what hacks people come up with as research in this area grows. (Tee-hee!) For example, [Junglist] wants to see the effect of simply running a UV light over a field rather than spraying with pesticides or fungicides would have.

An Open Assistive Robotic Arm To Help People Feed Themselves

Despite being otherwise capable, not everyone is able to feed themselves. [Julien]’s robot arm project aims to bring this crucial independence back to those people. Assistive devices in this space do exist, but as always they’re prohibitively expensive and the approval process is a nightmare. The development of the arm started by working closely with people who needed it at a local hospital. We note with approval, quite a few cardboard mock-ups to get the size and shape right before more formal work was done in CAD.

The robot arm only has to support a very light payload so its construction can be quite light. A frame of steel rods or plywood is all that’s required. We like how the motion is transferred from stepper motors to the joints of the arm by generously sized timing belts allowing the weight of the arm to remain towards the base. The team behind the project has gotten it to a point, but they’re hoping it will inspire community involvement as they move forward with it.

It’s worth noting, this is not the first assistive eating aid we’ve covered.

Let A CPR Robot Save The Day

Four highschool students in Lyon France are building a CPR robot, with the aim of removing the endurance problem faced by those delivering this form of essential first aid.

By every after action report, CPR is an emotionally and physically exhausting way to save a life. When someone’s heart stops beating their breathing stops too. After that there’s a very small window in which to keep just enough oxygen in the blood to prevent brain damage and organ failure. A person has to precisely position their hands and press, repeatedly, with enough force to break someone’s sternum in order to keep their heart pumping; sometimes for over fifteen minutes waiting for rescue to arrive. On top of that, depending on which school of thought they learned the technique, they may be required to also force air into the patients lungs.

While this pushes the boundary of human endurance, a robot would not have the same issue. In fact, many of the existing problems are solved. CPAP Machines can force air into lungs all day long. A motor and a mechanism could position and provide the mechanical pumping motion to keep the blood flowing. Sensors could tell when the heart takes back over. The machine is currently a proof-of-concept built from plywood, and off-the-shelf parts. Yet it can maintain the 30 compression – 2 breath cycle indefinitely on a CPR Dummy.

It’s an interesting idea; while defibrillators do exist, they don’t always get the heart going in time. We wonder if someone more medically inclined can weigh in on this interesting idea.

Landbeest, A Single Servo Walking Robot

Walking robots have a rich history both on and off the storied pages of Hackaday, but if you will pardon the expression, theirs is not a field that’s standing still. It’s always pleasing to see new approaches to old problems, and the Landbeest built by [Dejan Ristic] is a great example.

It’s a four-legged walker with a gait dictated by a cam-and-follower mechanism that allows it to perform the full range of leg movement with only one motor. Each cam can control more than one leg in synchronisation, and in his most recent prototype, there are two such mechanisms that work on opposite corners of a four-legged machine. The legs are arranged in such a way that the two corner-to-corner pairs pivot at their centres in a similar manner to a pair of scissors; allowing a servo to steer the robot as it walks.

The result certainly isn’t as graceful as [Theo Janssen]’s Strandbeest, from which it evidently takes inspiration for its name, but it’s no less capable for it. After the break you can see a video he’s posted which clearly illustrates its operation and demonstrates its ability to traverse obstacles.

The only thing that’s missing are the files and software should you wish to create your own. He’s unapologetic about this, pointing out that he’d prefer to wait until he is satisfied with it before letting it go. Since he’s put a lot of work in so far and shows no sign of stopping, we’re sure he’ll reach that point soon enough.

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Little Flash Charges In 40 Seconds Thanks To Super Capacitors

We’ve all committed the sin of making a little arduino robot and running it off AA batteries. Little Flash is better than that and runs off three 350 F capacitors.

In fact, that’s the entire mission of the robot. [Mike Rigsby] wants people to know there’s a better way. What’s really cool is that 10 A for 40 seconds lets the robot run for over 25 minutes!

The robot itself is really simple. The case is 3D printed with an eye towards simplicity. The brains are an Arduino nano and the primary input is a bump sensor. The robot runs around randomly, but avoids getting stuck with the classic reverse-and-turn on collision.

It’s cool to see how far these capacitors have come. We remember people wondering about these high priced specialty parts when they first dropped on the hobby scene, but they’re becoming more and more prevalent compared to other solutions such as coin-cells and solder tab lithium batteries for PCB power solutions.

Sensing, Connected, Utility Transport Taxi For Level Environments

If that sounds like a mouthful, just call it SCUTTLE – the open-source mobile robot designed at Texas A&M University. SCUTTLE is a low cost (under $350) robot designed for teaching Aggies at the Multidisciplinary Engineering Technology (MXET) program, where it is used for in-lab lessons and semester projects for the MXET 300 – Mobile Robotics undergraduate course. Since it is designed for academic purposes, the robot is very well documented, making it easy to replicate when you follow the instructions. In fact, the team is looking for others to build SCUTTLE’s and give them feedback in order to improve its design.

Available on the SCUTTLE website are a large collection of videos to walk you through fabrication, electronics setup, robot assembly, programming, and robot operation. They are designed to help students build and operate the mobile robot within one semester. Most of the mechanical and electronics parts needed for the robot are off-the-shelf and easy to procure and the rest of the custom parts can be easily 3D printed. Its modular design allows you the freedom to try different options, features and upgrades. SCUTTLE is powerful enough to carry a payload up to 9 kg (20 pounds) allowing additional hardware to be added. To keep cost low and construction easy, the robot uses a simple, two wheel drive system, using a pair of geared motors. This forces the robot to literally scuttle in a “non-holonomic” fashion to move from origin to destination in a sequence of left / right turns and forward moves, so motion planning is interestingly tricky.

The SCUTTLE robot is programmed using Python3 running under Linux and has been tested working on either a BeagleBone Blue or a Raspberry Pi. The SCUTTLE software guide is a good place to get acquainted with the system architecture.

The standard configuration uses ultrasonic sensors for collision avoidance, a standard USB camera for vision, and encoders coupled to the wheel drive pulleys for determining position with respect to the starting origin. An optional USB LiDAR can be added for area mapping. The additional payload capability allows adding on extra sensors, actuators or battery packs.

To complement information on the website, additional resources are posted on GitHub, GrabCAD and YouTube. Building a SCUTTLE robot ought to be a great group project at maker spaces wanting to get hackers started with Robotics. We have covered many Educational Robot projects in the past, but the SCUTTLE really shines with its ability to carry a pretty decent payload at a low cost.

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Bobble-Bot Teaches Modern Real-Time Robot Control

Bobble-Bot uses the standard inverted pendulum problem to teach modern robotic control using a Raspberry Pi, RT-Linux, and ROS.

We’re really impressed by the polish and design effort put into this project, and it’s no surprise that it’s a finalist in the 2019 Hackaday Prize. Bobble-Bot is a top heavy bot sitting on two BLDC motors. The brains of the operation is a Raspberry Pi running real-time Linux and ROS. This allows the robot to respond in a predictable manner to its inputs, and also allows for more control over thread priority than a regular kernel. In the past we’ve seen these inverted pendulum bots mostly being run on micro-controllers for just this reason, so it’s cool to see it make the jump to Linux.

Mechanically the bot can be printed on any consumer grade printer and assembled. We really appreciate the small details like making sure one screw size could be used to assemble the entire bot, eliminating the need for multiple tools.

They also have a simulator, and the bot’s software was built inside of that. It was a big moment when the real-world behavior finally matched the simulated performance. In fact, if you’re interested in the Bobble-Bot, you can try it out in simulation before committing to building the whole thing.

This project seems like a fun build for any hacker. We would have loved to have a project as polished and up-to-date as this one when we were learning controls in university. Video introducing it after the break.