How Amazon developed precision autonomy for Proteus

A couple of months ago, Amazon unveiled its first-ever autonomous mobile robot (AMR) Proteus. The company first entered the mobile robot space in 2012, when it acquired Kiva Systems for $775 million. Kiva Systems offered automated guided vehicles (AGVs) that have been at work in Amazon’s warehouses since. 

Proteus has a similar design to the Kiva robots. It slides under Amazon’s GoCarts, lifts them up and moves them across warehouses to employees or other robotic cells. Unlike the Kiva robots, which currently operate in caged-off spaces away from Amazon employees, Proteus is able to work freely among them. 

This change means that Proteus needs to be prepared to adapt quickly to unexpected changes in its environment. John Enright, principal engineer at Amazon Robotics, recently gave some insight into how the company developed the technology behind Proteus. He explained the approach to the AMR’s navigation in the video above.

“Our design focuses on safety, efficiency and cost-effectiveness,” Enright said. “We employ a wide range of diverse and redundant sensing modalities that allow us to provide certain guarantees on vehicle behavior.” 

Proteus’ job is to store, move and sort Amazon’s blue GoCarts, a central part of the company’s logistics operations. The AMR travels to where the carts are and slides underneath them to move them. It uses general navigation abilities to travel to the general location of the GoCarts, and then uses its high precision LiDAR to find the carts.

To slide under the cart, Proteus uses a two-step detection and motion process. First, the robot will perform a small “S” curve to remove any lateral error in its positioning under the GoCart. Next, it performs a straight motion to tunnel under the cart and lift it. 

Proteus carries the cart to its desired storage location, which it identifies with Amazon’s fiducial plus. Fiducial plus is a custom-made ground target that aids Proteus in its alignment capabilities and in finding storage cells. These fiducials help the robot to perform millimeter-level corrections on its positioning. 

The AMR has been deployed in Amazon’s outbound GoCart handling areas in its fulfillment and sorting centers. A source told The Robot Report Amazon will use both the Proteus AMRs and the Kiva-like AGVs moving forward.