Collaborative Quadruped Transportation in 3D Terrain with Constrained Diffusion

Abstract

Recently, multi-robot systems have gained significant attention for their promise of scalable efficiency, reliability, and cost savings. A crucial capability is collaborative transportation, where a team of robots works together to transport a payload. However, key challenges remain, such as potential conflicts between team-level decisions and individual-level robot controls, team kinematic constraints imposed by the robot-payload coupling, and diverse obstacles encountered in 3D terrain. We present Collaborative Quadruped Transportation with Constrained Diffusion (CQTD), enabling a team of closely coupled quadruped robots to collaboratively transport a payload across 3D terrain. A diffusion-based upper level learns terrain-aware team-level trajectories satisfying team kinematic constraints due to the payload coupling, while a lower level optimizes velocity controls of individual robots satisfying collision and anisotropic velocity constraints. Experiments in high-fidelity simulations and on real-world quadruped robot teams demonstrate that CQTD outperforms baseline methods in challenging 3D terrain scenarios requiring closely-coupled collaboration between the quadruped robots.