Globally Stable Neural Imitation Policies
This addresses safety concerns in robotics and planning by providing globally stable policies, though it is incremental as it builds on existing imitation learning methods.
The paper tackles the problem of imitation learning policies lacking stability in unexplored state regions, introducing Stable Neural Dynamical System (SNDS) to produce policies with formal stability guarantees, validated through simulation and real-world manipulator arm experiments.
Imitation learning presents an effective approach to alleviate the resource-intensive and time-consuming nature of policy learning from scratch in the solution space. Even though the resulting policy can mimic expert demonstrations reliably, it often lacks predictability in unexplored regions of the state-space, giving rise to significant safety concerns in the face of perturbations. To address these challenges, we introduce the Stable Neural Dynamical System (SNDS), an imitation learning regime which produces a policy with formal stability guarantees. We deploy a neural policy architecture that facilitates the representation of stability based on Lyapunov theorem, and jointly train the policy and its corresponding Lyapunov candidate to ensure global stability. We validate our approach by conducting extensive experiments in simulation and successfully deploying the trained policies on a real-world manipulator arm. The experimental results demonstrate that our method overcomes the instability, accuracy, and computational intensity problems associated with previous imitation learning methods, making our method a promising solution for stable policy learning in complex planning scenarios.