A team of researchers at New York University’s Tandon School of Engineering and the Max Planck Institute for Intelligent Systems in Tübingen and Stuttgart, Germany, designed a quadruped robot called Solo 8. The robot, an open-source design project, is named after its eight torque motor-controlled joints.
“We started to discuss motors that are used for drones that are very powerful and very small,” said Ludovic Righetti, associate professor of electrical and computer engineering and mechanical and aerospace engineering at NYU Tandon. “The other thing about the motors is that they’re cheap.”
The project started out with a single leg, but after the robot’s power-to-size ratio exceeded expectations, the quadruped was created.
Weighing 2.2 kilograms (4.85 lb), the robot is 24 cm tall when standing and can jump 65 cm high. When Solo falls, it can configure its legs into the standing position again. Videos of the robot’s other movements can be found online. The purpose of the project, according to Righetti, was research.
“We wanted to build a lightweight robot that can perform very dynamic motions,” he said.
The researchers published a paper titled “An Open Torque-Controlled Modular Robot Architecture for Legged Locomotion Research” in Robotics and Automation Letters, a peer-reviewed supplement of the IEEE Robotics & Automation Society.
“We think everything we do should be made public so everyone can actually see what we do and use it if they want to,” Righetti said of the project’s open-source nature. He related that some colleagues in France have made copies of Solo and collaborated with his team to develop a wireless communication card for the robot.
“People can contribute, which is great because now we can design new things and improve the design,” Righetti said. “That creates a community of people that can help each other.”
The technology does exist to scale up the quadruped robot and make it useful in different scenarios. As an example, Righetti said that a re-designed version could be used to traverse difficult terrain, especially in natural disaster situations. Solo 8 can also be used for research opportunities in animal-based movements, stress limit research and dynamic locomotion.
“The interesting thing about quadruped robots is they’re more stable than biped robots,” he said. “They can really go anywhere you might could go.”
Righetti said Solo 8 is a good educational opportunity for college students—and even high school students—to engineer. Solo 8 is affordable to create, with the materials costing approximately €4,000 ($4,500). For organizations with the capability to do so, some parts can be 3D printed; the construction files can be found online and are available under the BSD 3-clause license.
Righetti said that the collaboration with organizations around the world has opened doors for testing Solo 8’s abilities and updated designs. “This really was a team effort,” he related. “It is a big deal to be able to test a lot of things that we were unable to test before.”