Boston Dynamics has announced a new robotic hand for its Atlas humanoid. It has four digits including the thumb, and its degrees of freedom have nearly doubled from 7 to 13. The company deliberately left out the pinky, and pressure-based tactile sensors cover the fingertips and palm. A demo shows Atlas working with a power drill, and the design is aimed at real use in automotive plants.
A 13-DOF Hand Without a Pinky
The hand has 13 degrees of freedom in total: 4 in the thumb and 3 in each of the other three fingers. It is roughly the size of a large adult hand and closely follows a human shape.
The missing pinky is the most striking choice. The team tested finger counts through 3D-printed mockups and simulation, and concluded that a fifth finger would add parts and failure points out of proportion to the dexterity it provides. One engineer said team members worked with their little fingers taped down and found they could manage without one.
The hand is directly actuated using a single type of actuator. It is fully encapsulated with no exposed cables, and the actuators are designed for force transparency (backdrivability) so the hand can yield to impacts instead of breaking.
Touch and Tool Handling
Dense pressure tactile sensors cover the fingertips and palm, detecting even subtle changes in contact.
In the demos, the thumb tip slides along the length and across the width of the other fingers. Besides pinch and three-finger grasps, the hand supports trigger-style tool grips for drills, torque drivers, grinders, nail guns and welding torches. Tasks that require re-gripping, such as turning a nut between the fingers or inserting a drill bit, have also been shown.
Training in Simulation
The design centers on sim-to-real transfer. Reinforcement learning is run with randomized motor torque, surface friction, object shapes and disturbances, and a rigid drive train improves the fidelity of physics simulation. The previous 7-DOF hand focused on grasping a wide variety of objects, while the new one is built for manipulating them.
Path to the Factory Floor
On September 21, Boston Dynamics opened the Robotics Metaplant Application Center at Hyundai Motor Group Metaplant America in Georgia, where Atlas will be trained and validated for automotive manufacturing. According to reports, deployment is planned to start with parts sequencing in 2028 and expand to parts assembly from 2030.
Summary
The new Atlas hand pairs 13 degrees of freedom with tactile sensing and a fully encapsulated direct drive to handle tools. How well it performs on a real factory floor, pinky-less design included, remains to be tested.
References
[1] https://bostondynamics.com/blog/robot-hands-for-modern-ai-and-real-work/
[2] https://www.therobotreport.com/boston-dynamics-opens-metaplant-application-center-train-atlas-humanoid-robots/
