Shared WBC Architecture
Our architecture uses a shared, task-agnostic whole-body controller (WBC) that executes all skills through a unified low-level control interface. This enables skill reuse and simplifies composition without switching control laws at skill boundaries. Independently trained high-level skills generate task-level commands that are executed through the shared WBC, which produces joint-level PD targets tracked by a low-level PD controller on the robot.
We extend this architecture with a rollout-based coverage expansion method: closed-loop executions from composed execution in simulation are aggregated to further train the shared WBC. This simple data aggregation procedure improves robustness over long horizons while preserving a single, task-agnostic whole-body controller shared across all skills.