Abstract:Ensuring safety in autonomous systems requires controllers that satisfy hard, state-wise constraints without relying on online interaction. While existing Safe Offline RL methods typically enforce soft expected-cost constraints, they do not guarantee forward invariance. Conversely, Control Barrier Functions (CBFs) provide rigorous safety guarantees but usually depend on expert-designed barrier functions or full knowledge of the system dynamics. We introduce Value-Guided Offline Control Barrier Functions (V-OCBF), a framework that learns a neural CBF entirely from offline demonstrations. Unlike prior approaches, V-OCBF does not assume access to the dynamics model; instead, it derives a recursive finite-difference barrier update, enabling model-free learning of a barrier that propagates safety information over time. Moreover, V-OCBF incorporates an expectile-based objective that avoids querying the barrier on out-of-distribution actions and restricts updates to the dataset-supported action set. The learned barrier is then used with a Quadratic Program (QP) formulation to synthesize real-time safe control. Across multiple case studies, V-OCBF yields substantially fewer safety violations than baseline methods while maintaining strong task performance, highlighting its scalability for offline synthesis of safety-critical controllers without online interaction or hand-engineered barriers.




Abstract:Ensuring safe and generalizable control remains a fundamental challenge in robotics, particularly when deploying imitation learning in dynamic environments. Traditional behavior cloning (BC) struggles to generalize beyond its training distribution, as it lacks an understanding of the safety critical reasoning behind expert demonstrations. To address this limitation, we propose GenOSIL, a novel imitation learning framework that explicitly incorporates environment parameters into policy learning via a structured latent representation. Unlike conventional methods that treat the environment as a black box, GenOSIL employs a variational autoencoder (VAE) to encode measurable safety parameters such as obstacle position, velocity, and geometry into a latent space that captures intrinsic correlations between expert behavior and environmental constraints. This enables the policy to infer the rationale behind expert trajectories rather than merely replicating them. We validate our approach on two robotic platforms an autonomous ground vehicle and a Franka Emika Panda manipulator demonstrating superior safety and goal reaching performance compared to baseline methods. The simulation and hardware videos can be viewed on the project webpage: https://mumukshtayal.github.io/GenOSIL/.