Agility Robotics Co-Founder Reveals Why He Can't Love Digit 5

For more than ten years, Jonathan Hurst, co-founder of Agility Robotics, has been developing robots that move 'naturally'. Yet the company’s newest humanoid, Digit 5, is not what he set out to make. 

In an essay published by IEEE Spectrum, Hurst described how commercial imperatives and the need for safety have made Digit a more complex and weighty machine for industrial use than initially planned. 

“But I cannot love Digit 5,” he wrote, in recognition of the concessions one must make to put a commercially viable product to market after all that research. 

The admission offers an unusual look at the challenges humanoid developers face when they produce robots for the factory or warehouse rather than an experimental machine. 

Hurst had originally envisioned robots to get lighter and more agile over time. In the case of Digit 5, the demands of industry have dictated otherwise. The legs are a prime example; prior Digit models had a backward-bending leg design inspired by research into dynamic walking, which was fine until the robot had to put in a deep squat and lift something heavy.  

Digit 5 has a more humanlike arrangement, so the knee and hip motors can be put to work together when lifting. The new model is built to handle 23 kg containers repeatedly as a warehouse would require. 

Then there is the matter of safety. Agility is developing systems to have Digit 5 detect a person in proximity and come to a halt or sit down. 

Hurst outlined a planned safety response in which the robot puts down its load, sits and disables its motors when someone approaches too closely. These features would require more sensors, computing hardware and mechanical components, all of which increase the robot's weight and complexity. 

Commercial requirements have also influenced its battery system. In a new partnership with Nyobolt, Agility is working on fast-charge batteries that will give 90 minutes of run time in nine minutes of charge. They are aiming for 20 hours of productivity in a day, although those figures remain projected capabilities as of now. 

Customers should have their early access to Digit 5 in the first half of next year. 

Hurst says: “Customers and product requirements didn’t ruin my vision. They showed me what I had not considered.”