Robotic Dog Looks like a Mutt


It runs, it jumps—and it could be yours. Students in Stanford University’s Robotics Club developed and built a four-legged robot about the size of an average beagle, and dubbed it “Stanford Doggo.”

The quadruped pooch was built from scratch with off-the-shelf components and trots, runs, jumps, dances and comes back when you call it. They liked Doggo so much, they made it available to anyone else who wants to build one or improve on the model. The club created an open-source link where all their work is available for review.

Nathan Kau, a mechanical engineering student and the team lead on the project, says the idea developed after tinkering with drones and looking at other quadrupeds used in research. But those models cost in the tens of thousands of dollars, so Kau looked to develop a cheaper version.

After gaining some funding from the robotics club, he and other team members increased their commitment to the project, finishing work after two years of development.

Kau estimates the Extreme Mobility Team of the club spent about $3,000 to produce the bot, compared to tens or hundreds of thousands of dollars needed for robots that require customized parts or software. “It was hard scrounging about for different resources,” he said. “It’s not the best robot out there but then it doesn’t require a million dollars either.”

To build it from scratch, they had to research what supplies were available and test each part as they made it, without using simulations. Several prototypes were developed before they produced the final version that can maneuver through different terrain. To do that it uses motors that sense external forces and determine the force and torque each leg needs to apply.

The motors recompute at 8,000 times per second, and act like a system of virtual springs to place the robot into appropriate form when they sense it is out of position. The robot, somewhat surprisingly, jumps two to three and a half feet in the air, depending on how the software is configured. The students also taught Doggo to do a backflip, operating it on padding just in case.

Team members are also keen on making their work available to anyone interested in replicating or improving on their work. “All of our resources came from the open source community,” says Kau. We want to emulate that kind of community. People can have the baseplate to a full set of software. I know it is hard scrounging around for different resources. This is an all-in-one package.”

The idea is aimed at high schools or other colleges that may not have the funds to develop a robot. The team has uploaded the entire CAD model. The design was done in Fusion 360 and includes all mechanical parts needed to source. In their description, the team noted the coaxial mechanism that drives each leg in the most complex mechanical component and the most troublesome to perfect.

The team already is pushing the idea further, after finishing work on a similar but larger version of Doggo that can carry some six kilograms of equipment. Keeping the theme, it is named Stanford Woofer.

John Kosowatz is senior editor at Mechanical Engineering magazine.

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