We’ve seen robots drawing and painting before. But Beachbot does art on a whole different scale. Developed by a team from Disney Research Zurich and ETH Zurich, the robot can autonomously create giant sand drawings by dragging a rake-like tool on a beach.
Paul Beardsley, a principal research scientist at Disney Research Zurich, says he wanted to build an artist robot that could keep creating new artwork. Instead of using paint, he wanted to explore a less permanent medium. “Sand drawing is perfect because it’s an infinitely reuseable canvas,” he says.
Beachbot carries a computer with Wi-Fi, a inertial measurement unit (IMU), and a laser scanner. It uses the laser, mounted on its back, to detect four poles placed on the beach. The poles delimit the boundaries of a “canvas,” and the robot uses the laser data and the IMU to locate itself and navigate with millimiter accuracy within that area.
Building a machine that could drive and draw on the sand presented some challenges. Beardsley and his colleagues tested different drawing tools before settling on the rake mechanism, which has individually controlled prongs that can be lowered or raised to create thick or thin lines on the sand. They also experimented with different wheels, looking for a design that wouldn’t leave pronounced tracks on the sand. But the hardest part of the project was developing algorithms to transform a picture into a trajectory that the three-wheeled robot could drive.
“Robot sand art is basically a path planning problem in robotics,” Beardsley explains. Based on the lines of a drawing, the robot computes a trajectory that most closely approximates them. For big art pieces, the trajectory still has to be adjusted manually. But the group hopes to completely automate the process, so that you can give any picture to the robot and it will generate a line drawing and compute the corresponding path.
Beachbot currently works on 10-meter-by-10-meter-canvases. “But in principle we can scale up to kilometer long drawings that extend all along a beach,” Beardsley says. “The dream is to create huge amazing drawings like the Nazca Lines.”