Fishes and robots and Beagles, oh my!

BY JASON KRIDNER
Software Architecture Manager for Embedded Processors
Texas Instruments, www.ti.com
and co-founder of www.BeagleBoard.org

Have you ever wished you had a robot that would help you perform a certain function? You’re probably thinking “YES!” But who has the time and technology to do that? What if we told you that there are boards out there that could help ease your development woes, and there is even a community to help you build out your project? Take a closer look at three developers who used BeagleBoard.org designs to create three very different robots.

Put the pedal to the metal with 'Fish on Wheels'
Ever wanted your pet goldfish to play fetch? Thanks to “Fish on Wheels,” a robotic car from Studio diip, that is now possible—sort of.

As Goldie the goldfish swims, a Logitech C910 webcam stationed overhead communicates with computer-vision software running on a Sitara-processor-powered BeagleBoard-xM computer. Using the contrast of the fish with the bottom of the fish tank, the computer is able to determine which direction the fish is swimming. BeagleBoard-xM then talks to the chassis, powered by a Seeed Studio Hercules Robot platform with Arduino, to tell it to drive in the direction the fish is swimming.

The founders thought of developing Fish on Wheels so they could have something that would showcase the possibilities of computer-vision technology. They then came up with the idea that with computer vision, even animals would be able to control devices. They thought that best way to show this was to enable fish to drive their own aquarium ― wherever they want to go.

Fig. 1: Fish on Wheels showcases computer vision program that enables animals to control devices such as a fish in a motorized water tank on wheels.

It wasn’t as easy as it sounds. The team faced a challenge in being able to smoothly control the motors of the robot platform so that water would not spill over the edge of the aquarium, leaving Goldie out to dry. They tested various options with the BeagleBoard-xM and were eventually able to fine-tune the device.

They chose BeagleBoard-xM because it offered the team the flexibility to quickly create a working solution that gets the job done. They also liked that it can run on a battery for quite a while, so the whole device can run autonomously.

Take a deeper dive with OpenROV
Whether you want to explore the seas for science and education, “snorkel” for fish and coral without getting wet, or hunt for buried treasure in unexplored seas, OpenROV is something you need to check out!

David Lang and Eric Stackpole created OpenROV—an underwater robot that can be controlled with a laptop — in a garage in Cupertino, CA, with the goal of exploring an underwater cave. After finding a global community of co-developers on Kickstarter, the project evolved, developing into a global community of DIY ocean explorers who are using and improving the OpenROV design in oceans and lakes around the world.

The newest OpenROV robot — OpenROV 2.5 — was introduced in September 2013. It is now powered by BeagleBone Black (it was formerly powered by the original BeagleBone), enabling lower-cost and higher-performance robots. Its many other upgrades include a durable polypropylene shell, more efficient propellers, added buoyancy to support more payloads, more robust battery tubes, and laser-range and size-calculating capability. These submarine-like robots are open-source, enabling anyone to use their code to add new features and functionality. In fact, there are now more than 500 OpenROVs swimming in more than 50 countries around the world. The OpenROV kit, which comes with all the hardware needed to assemble your own OpenROV, can be built in a single weekend. If you are more adventurous, you can make your own OpenROV from scratch, using design files on OpenROV.com for support.

 Fig. 2: OpenROV is an underwater robot that can be controlled with a laptop to explore underwater caves.

Standing is just the first lesson to teach your Beagle
Inspiration is not an easy thing to come by, and no one can predict when it will strike. The light bulb suddenly flashes on overhead, and the gears inside your brain start to turn. The excitement of the “Ah hah!” moment is great but often short-lived when the realization of logistics come into play.

Engineers often find themselves in this situation when a new idea for a robot pops into their head, but then there is the complicated process of crafting the internal hardware and writing the software to actually make it work. James Strawson, Ph.D. student at the University of California, San Diego (UCSD) and founder of Strawson Design, grew tired of having to create new circuits for every new robot that he worked on, so he unified his current and future robotics projects under one hardware and software platform, thus creating the “Robotics Cape.”

The Robotics Cape works with BeagleBone Black to make a mobile robotics platform. It includes two-cell lithium battery charging, protection and monitoring circuitry to make sure the robot is always charged and ready to play with. The Robotics Cape also provides plug-and-play connectors to easily interface with common components so you can build your robot without soldering or messy wiring. It was obvious for Strawson to choose BeagleBone Black when picking a Linux development board.

“First and foremost, robotics projects typically require the control board to interface with custom circuitry,” said Strawson. “BeagleBone Black provides an enormous array of hardware interface pins for functions such as GPIO, PWM, eQEP, I2C and more, which is exactly what tinkerers and prototypers need. BeagleBone Black is also a fantastically neat and tidy package that is ideal for tiny robots.”

When creating the cape, Strawson picked the features he felt would apply to the largest number of applications. Strawson first used the Robotics Cape to teach a senior embedded controls course at UCSD. Each student built their own BeagleMIP balancing robot based on the cape and was taught to design and implement a discrete-time controller to make the robot balance upright and drive. The University Program from Texas Instruments donated BeagleBone Black computers to UCSD to enable these projects.

Fig. 3: The Robotics Cape unifies robot designs under one hardware and software platform.

“We learned a lot about implementing dynamic control systems in a Linux environment,” said Strawson. “I was pleased to teach fellow mechanical engineers how to dive into the world of embedded programming and circuit design.”

Strawson is working on a few refinements on the board layout and connectivity before bringing the Robotics Cape to market. He also looks forward to spending more time developing control systems with BeagleBone Black. He is testing a quad-rotor controller based on BeagleBone Black, as well as a Robotics Cape combination designed to be inexpensive and easy to repair while offering the networking capability and processing power of BeagleBone Black.

The Robotics Cape is still a work in progress, but will be available for sale in the coming months.