Atlas and his unique stand-up move at the Hyundai factory in Georgia

One of Atlas’s puzzling movements is turning his legs upside down to create momentum to stand up while lying on the ground. This movement appears in many videos of this robot’s activities, making viewers wonder why it doesn’t stand up the way humans usually do.

According to Katy Muhlrad, senior female software engineer at Boston Dynamics, the move is performed based on safety, efficiency and helps test the system. Humans can stand up naturally, without thinking, thanks to continuous haptic feedback from throughout the body, she said, but robots have much fewer sensors and must calculate each step of movement.

“It’s entirely possible for a robot to step on its own arm,” Muhlrad explains, while a human would instinctively avoid this. Therefore, Atlas had to re-adjust the position of his limbs to ensure there were no obstructing parts.

To get up from a lying position, Atlas will first lift the legs and fold them back, confirming the feet are not touching anything and that any foot sensors are providing accurate data. Next, the robot performs a controlled push to lift its body up, while turning its head in the right direction. The pushing action is designed so that the robot stands upright at the center of gravity, helping to reduce energy consumption.

Since the Atlas does not have full-body tactile sensors, the testing phase is critical. If an abnormality is detected, it immediately stops and lies down. Boston Dynamics says this energy-efficient and reliable way to get up is essential for the robot to stay active during repetitive tasks.

The Atlas humanoid robot is about 1.5 m tall, weighs 89 kg, has 28 degrees of freedom (DoF), is equipped with Lidar and stereoscopic image sensors for navigation, and can sprint at a speed of 2.5 m per second.

Atlas is expected to operate in testing at the Hyundai Motor Group Metaplant America factory in Georgia (USA) later this year. Additionally, it was built with the goal of being able to go anywhere. “The robot will do the strenuous work like lifting heavy objects or carrying things that are difficult for humans to do,” Kerri Neelon, a spokesperson for Boston Dynamics, told Wired.