CoRL 2025 LEAP Workshop Best Paper Award ICRA 2026 Best Paper Award on Planning and Control ICRA 2026 Best Conference Paper Award

SymSkill: Symbol and Skill Co-Invention for Data-Efficient and Reactive Long-Horizon Manipulation

University of Pennsylvania

SymSkill jointly learns symbolic predicates, operators, and stable SE(3) DS skills from 5 min of unlabeled play demos, then plans symbolically to compose skills and recover from failures in real time on long‑horizon manipulation tasks.

Multi-step manipulation in dynamic environments remains challenging. Imitation learning (IL) is reactive but lacks compositional generalization, since monolithic policies do not decide which skill to reuse when scenes change. Classical task-and-motion planning (TAMP) offers compositionality, but its high planning latency prevents real-time failure recovery. We introduce SymSkill, a unified framework that jointly learns predicates, operators, and skills from unlabeled, unsegmented demonstrations, combining compositional generalization with real-time recovery. Offline, SymSkill learns symbolic abstractions and goal-oriented skills directly from demonstrations. Online, given a conjunction of learned predicates, it uses a symbolic planner to compose and reorder skills to achieve symbolic goals while recovering from failures at both the motion and symbolic levels in real time. Coupled with a compliant controller, SymSkill supports safe execution under human and environmental disturbances. In RoboCasa simulation, SymSkill executes 12 single-step tasks with 85% success and composes them into multi-step plans without additional data. On a real Franka robot, it learns from 5 minutes of play data and performs 12-step tasks from goal specifications.

Offline Co-Invention, Online Reactive Execution

Pipeline

SymSkill framework pipeline showing offline learning and online execution
SymSkill co-invents symbols and skills from demonstrations, producing symbolic operators and skills that can be reused by a planner.

Online Algorithm

SymSkill online symbolic planning and reactive execution algorithm
At deployment, the online algorithm alternates between symbolic planning, skill execution, and real-time recovery.

Composing Learned Operators and Skills

Simulation Experiment

Learning operators and skills from individual tasks, then combining them

SymSkill first learns reusable task structure from individual demonstrations, then composes the learned skills into longer symbolic plans without collecting new multi-step demonstrations.

Open Drawer

Close Drawer

Pick and Place

Real Robot

Disturbance rejection and reactive obstacle avoidance using modulation at 1x speed

The controller and online symbolic execution loop allow the robot to remain responsive when the workspace changes during execution.

Real Robot

Demo with operator annotation at 1x speed

BibTeX

@misc{shao2025symskill,
  title={SymSkill: Symbol and Skill Co-Invention for Data-Efficient and Reactive Long-Horizon Manipulation},
  author={Shao, Yifei Simon and Zheng, Yuchen and Sun, Sunan and Chaudhari, Pratik and Kumar, Vijay and Figueroa, Nadia},
  year={2025},
  eprint={2510.01661},
  archivePrefix={arXiv},
  primaryClass={cs.RO},
  url={https://arxiv.org/abs/2510.01661}
}