Agility Robotics’ Digit adds arms to Cassie’s bipedal design

Despite recent advances with bipedal robots, most are not graceful, and they have not been able manipulate objects with the dexterity of stationary robotic arms. Agility Robotics Inc. yesterday unveiled Digit, which builds on the design of its ostrich-like Cassie robot.

Digit includes an upper torso, more sensors, and additional computing capabilities. Most importantly, it has two arms with four degrees of freedom. These arms are useful for mobility as well as for grasping.

“For us [humans], arms are simultaneously a tool for moving through the world — think getting up after a fall, waving your arms for balance, or pushing open a door — while also being useful for manipulating or carrying objects,” stated Jonathan Hurst, co-founder and chief technology officer of Albany, Ore.-based Agility Robotics.

Editor’s note: Agility Robotics CEO Damion Shelton and Boston Dynamics CEO Marc Raibert spoke at last year’s Robotics Summit. Register now for this year’s Robotics Summit & Expo, which will be on June 5 and 6 in Boston.

For robots to be useful in spaces designed for humans, they need to be more nimble, perceptive, and robust, Hurst said in IEEE Spectrum. Even though robot designs have been modeled after the behavior of bipeds such as birds, understanding gait is more of a challenge than computing or power, he said.

Hurst’s team at Oregon State University worked with researchers at Carnegie Mellon University and the University of Michigan on the ATRIAS biped, which used passive dynamics and a spring-mass system to address the challenges of bipedal locomotion.

He later developed Cassie on the same principles and included motion planning. Agility’s simulation software can help developers evaluate Cassie’s capabilities.

Digit has brains and brawn for delivery

Digit’s arms can help it balance or pick itself up after a fall, and it adds perception to operate in range of environments. It was designed with certain commercial applications in mind, such as stacking boxes in warehouses and delivering parcels to customers’ doorsteps.

Agility Robotics noted that while Digit is still in testing, the robot is capable of picking up and stacking boxes weighing up to 40 lb. (18 kg).

On the controls side, Digit’s torso includes two multi-core CPUs and a modular bay for systems for perception and machine learning. The robot’s application programming interface (API) can be controlled onboard or via a wireless link.

While Cassie initially had some difficulty with stairs, Digit has advanced footstep planning. Agility Robotics claimed that users can set up the robot and get it running out of the box in only five minutes.

“Most of our Cassie customers were specifically interested in developing controllers for legged locomotion,” said Damion Shelton, co-founder and CEO of Agility. “We developed Digit for the much larger audience of users who wish to explore broader applications that are enabled through legged mobility, rather than focusing only on the mobility itself.”

Availability and expectations

Agility Robotics, which raised $8 million last spring, said it will announce pricing for Digit midyear. It plans to begin deliveries in the first quarter of 2020 and will offer warranty support and applications engineering assistance.

Legged and humanoid robots are not suitable for every task, but they are what many people think of when they discuss robots. Legged robots could be useful in locations not designed for industrial automation, ultimately bringing automation to households.

Ocado Technology’s ARMAR-6 and the INNFOS XR-1 have humanoid torsos, but they still rely on wheels, which are energy efficient but limit mobility. Boston Dynamics’ videos of its acrobatic Atlas humanoid remain popular, and it plans to offer its quadruped SpotMini for sale this year.

Last fall, Toyota Motor Corp. demonstrated remote control of its T-HR-3 humanoid robot over a 5G network. UBTECH Robotics Inc. showed off its Walker bipedal service robot at CES 2019.

The humanoid robot market could grow from $320.3 million in 2017 to $3.9 billion in 2025, said Markets and Markets. The work to refine bipedal robots to the point where they can walk where humans do and easily manipulate objects continues, with Digit as a step forward.