Calf-Integrated Arms for Bimanual Quadruped Loco-Manipulation
For quadruped loco-manipulation, this design provides a novel way to perform bimanual tasks without sacrificing stance or requiring rearing, addressing a key limitation of existing approaches.
This paper introduces a quadruped robot with manipulators integrated into its front calves, enabling bimanual manipulation at ground level while keeping all four feet planted. The design achieves autonomous long-horizon tasks like cabinet opening, cooperative lifting, and object handover in simulation.
Most quadruped loco-manipulation designs trade manipulation capability against stance. A trunk-mounted arm sits high and usually carries a single arm; using the legs as manipulators lifts the manipulating leg off the ground; and even leg-mounted grippers reach two-handed tasks only by rearing onto the hind legs. This paper integrates a manipulator with a prismatic slider, two revolute joints, and a gripper into each front calf of a Unitree Go2. The two arms grasp objects at ground level and manipulate with both hands while all four feet stay planted, without rearing. With one arm carrying, the base stays free to walk. A vision-language model sequences skills from a predefined library at each skill boundary, conditioned on the head-camera image and task state, for long-horizon autonomy. In simulation, the design performs three bimanual tasks: a long-horizon cabinet task under autonomous skill selection, a cooperative two-handed lift, and an inter-arm handover.