Ensuring reliable performance in situations outside the Operational Design Domain (ODD) remains a primary challenge in devising resilient autonomous systems. We explore this challenge by introducing an approach for adapting probabilistic system models to handle out-of-ODD scenarios while, in parallel, providing quantitative guarantees. Our approach dynamically extends the coverage of existing system situation capabilities, supporting the verification and adaptation of the system's behaviour under unanticipated situations. Preliminary results demonstrate that our approach effectively increases system reliability by adapting its behaviour and providing formal guarantees even under unforeseen out-of-ODD situations.
Figures & tables
Figure 1. SAVE approach overview: pre-deployment (A,B) and deployment (M,A,P,E) phases with shared knowledge.
ID
Property violated
Worst critic- ality score
SAVE success (no violations)
Critical situations avoided
1
[ Φ2 ]
0.03890
True
[s2, s3]
2
[ Φ2 , Φ1 ]
0.03482
True
[s2, s3, s5]
3
[ Φ2 , Φ1 ]
0.03556
True
[s3, s4]
4
[ Φ2 , Φ1 ]
0.04483
True
[s5, s1, s3, s2]
5
[ Φ2 , Φ1 ]
0.04905
False
-
…16
[ Φ2 ]
0.04994
True
[s1]
Table 1. SAVE adaptation results after a violation is detected. Without adaptation, the baseline fails in all cases.
Event
Baseline Outcome
SAVE Response
Vessel deceleration (out-of-ODD)
Collision expected within the next 50 timesteps ( f2 ), detected at time t1 . Collision happens in situation i at time t2 .
Controller adapted at t1 . Critical situation i and collision avoid.
Requirement Φ1 (safe TTC)
Violated at time t2 .
Satisfied post-adaptation at time t3
Requirement Φ2 (near collision)
Violated at time t4 .
Satisfied post-adaptation at time t5 .
Table 2. SAVE adaptation example.
Figure 2. SAVE execution times to get criticality scores.
Safety-critical control of uncertain, adaptive systems often relies on conservative, worst-case uncertainty bounds that limit closed-loop performance. Online conformal prediction is a powerful data-driven method for quantifying uncertainty when truth values of predicted outputs are revealed online; however, for systems that adapt the dynamics without measurements of the state derivatives, standard online conformal prediction is insufficient to quantify the model uncertainty. We propose Staggered Integral Online Conformal Prediction (SI-OCP), an algorithm utilizing an integral score function to quantify the lumped effect of disturbance and learning error. This approach provides long-run coverage guarantees, resulting in long-run safety when synthesized with safety-critical controllers, including robust tube model predictive control. Finally, we validate the proposed approach through a numerical simulation of an all-layer deep neural network (DNN) adaptive quadcopter using robust tube (MPC), highlighting the applicability of our method to complex learning parameterizations and control strategies.
Daniel M. Cherenson, Dimitra Panagou
Robotics Department, University of Michigan, Ann Arbor, MI, USA
In safety-critical Cyber-Physical Systems (CPS), trajectory prediction guides downstream planning and control. Deep learning models forecast well on validation data, but their reliability drops in out-of-distribution (OOD) scenarios driven by environmental uncertainty or rare traffic behaviors [1, 2]. Such failures are often silent: forecasts stay spatially plausible while accuracy collapses, and reported uncertainty does not rise [3]. Detection is hard because traffic conditions and interaction patterns keep evolving, yet the safety-critical nature of autonomous driving (AD) demands formal guarantees on detection delay and false-alarm rate. Following [4], we reframe OOD monitoring as quickest changepoint detection (QCD), a principled statistical framework with well-established theory. We find that the evolution of prediction errors on in-distribution (ID) data is well modeled by a Hidden Markov Model (HMM). Building on this, we extend a recent cumulative Maximum Mean Discrepancy approach to our setting. The method needs no detailed prior knowledge of the post-change distribution, yet admits provable delay and false-alarm guarantees. On three real-world driving datasets, it reduces detection delay while staying robust to heavy-tailed distributions and unknown post-change conditions.
Tongfei Guo, Lili Su
Department of Electrical and Computer Engineering, Northeastern University, Boston, MA, USA.
Control barrier functions are an effective model-based tool to formally certify the safety of a system. However, transferring their theoretical guarantees to real-world robotics systems requires high model fidelity. For example, payloads or wind disturbances can cause significant model perturbations to an aerial vehicle, leading to safety compromises. In this work, we propose a certifiable online learning-enhanced robust adaptive control barrier function, which adapts to disturbances using a Neural ODE and quantifies its adaptation uncertainty with conformal prediction. Our approach guarantees safety at all time under unknown time-varying model disturbances. It adopts a conservative strategy when the adaptation uncertainty is high; and efficiently adapts to reduce controller conservativeness as it receives more data. Our approach provides a provable safety guarantee with a probability bound under suitable Lipschitz smoothness assumptions on the underlying model and trajectory. These results demonstrate the potential of our method as a practical safety controller for robotics system operating under model perturbations.
Lishuo Pan, Mattia Catellani, An Cao +2
Department of Computer Science, Brown University, Providence, RI 02912 USA · Department of Sciences and Methods for Engineering, University of Modena and Reggio Emilia, 41121 Modena, Italy · Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125 USA