Three-armed robot sushi chef learns how to cut fish like a pro

A new three-armed robot has learned to cut fish for sashimi. This is a difficult task for machines: the slippery fillet changes shape when touched, and cutting requires special precision.

How does Sashimi-Bot work?

Sverre Herland from the Norwegian University of Science and Technology and his colleagues created a system with three manipulators. Details published in npj Robotics magazine.

The first hand straightens the fish and holds it. The second holds the knife and cuts. The third one picks up the pieces with chopsticks and places them on a plate.

Instead of step-by-step instructions, the team used AI that learns from its own experience. The system was put through a virtual simulation where it repeated the task thousands of times, learning how to properly straighten a fish through trial and error.

Sensitive knife

To make the cutting hand “feel” the touch, engineers used machine learning. They trained a computer model on thousands of readings from a tactile sensor near the knife.

Separately, we trained the model to recognize the moment the blade touched the cutting board. This allows you to adjust the cutting path in real time and not cut too deep.

Salmon test

Tests on real salmon fillets showed that the Sashimi-Bot was slower than a human, but successfully straightened, held and cut the slippery fish, and then carefully placed the pieces on a plate.

“This work is an important milestone in the robotic control of deformable volumetric objects,” the authors write. “It could inspire many other real-world applications.”

By successfully automating delicate operations, the researchers showed that the system was capable of handling fragile objects. In the future, such robots could sort soft waste in recycling plants or assist in medical procedures.