aci
Adaptive Regime-Switching Forecasts with Distribution-Free Uncertainty: Deep Switching State-Space Models Meet Conformal Prediction
LU, Echo Diyun, Findling, Charles, Clausel, Marianne, Leite, Alessandro, Gong, Wei, Kersaudy, Pierric
Regime transitions routinely break stationarity in time series, making calibrated uncertainty as important as point accuracy. We study distribution-free uncertainty for regime-switching forecasting by coupling Deep Switching State Space Models with Adaptive Conformal Inference (ACI) and its aggregated variant (AgACI). We also introduce a unified conformal wrapper that sits atop strong sequence baselines including S4, MC-Dropout GRU, sparse Gaussian processes, and a change-point local model to produce online predictive bands with finite-sample marginal guarantees under nonstationarity and model misspecification. Across synthetic and real datasets, conformalized forecasters achieve near-nominal coverage with competitive accuracy and generally improved band efficiency.
- North America > United States > Pennsylvania (0.04)
- North America > United States > Alaska (0.04)
- North America > United States > California > Santa Clara County > Palo Alto (0.04)
- North America > United States > Pennsylvania (0.04)
- North America > United States > Alaska (0.04)
- North America > United States > California > Santa Clara County > Palo Alto (0.04)
Towards Generalizable Safety in Crowd Navigation via Conformal Uncertainty Handling
Yao, Jianpeng, Zhang, Xiaopan, Xia, Yu, Wang, Zejin, Roy-Chowdhury, Amit K., Li, Jiachen
Mobile robots navigating in crowds trained using reinforcement learning are known to suffer performance degradation when faced with out-of-distribution scenarios. We propose that by properly accounting for the uncertainties of pedestrians, a robot can learn safe navigation policies that are robust to distribution shifts. Our method augments agent observations with prediction uncertainty estimates generated by adaptive conformal inference, and it uses these estimates to guide the agent's behavior through constrained reinforcement learning. The system helps regulate the agent's actions and enables it to adapt to distribution shifts. In the in-distribution setting, our approach achieves a 96.93% success rate, which is over 8.80% higher than the previous state-of-the-art baselines with over 3.72 times fewer collisions and 2.43 times fewer intrusions into ground-truth human future trajectories. In three out-of-distribution scenarios, our method shows much stronger robustness when facing distribution shifts in velocity variations, policy changes, and transitions from individual to group dynamics. We deploy our method on a real robot, and experiments show that the robot makes safe and robust decisions when interacting with both sparse and dense crowds. Our code and videos are available on https://gen-safe-nav.github.io/.
- North America > United States > California > Riverside County > Riverside (0.04)
- Asia > South Korea > Seoul > Seoul (0.04)
Mirror Online Conformal Prediction with Intermittent Feedback
Wang, Bowen, Zecchin, Matteo, Simeone, Osvaldo
Online conformal prediction enables the runtime calibration of a pre-trained artificial intelligence model using feedback on its performance. Calibration is achieved through set predictions that are updated via online rules so as to ensure long-term coverage guarantees. While recent research has demonstrated the benefits of incorporating prior knowledge into the calibration process, this has come at the cost of replacing coverage guarantees with less tangible regret guarantees based on the quantile loss. This work introduces intermittent mirror online conformal prediction (IM-OCP), a novel runtime calibration framework that integrates prior knowledge, while maintaining long-term coverage and achieving sub-linear regret. IM-OCP features closed-form updates with minimal memory complexity, and is designed to operate under potentially intermittent feedback.
- Europe (0.14)
- Asia > Middle East > Jordan (0.04)
Beyond Conformal Predictors: Adaptive Conformal Inference with Confidence Predictors
Conformal prediction (CP) is a robust framework for distribution-free uncertainty quantification, but it requires exchangeable data to ensure valid prediction sets at a user-specified significance level. When this assumption is violated, as in time-series or other structured data, the validity guarantees of CP no longer hold. Adaptive conformal inference (ACI) was introduced to address this limitation by adjusting the significance level dynamically, ensuring finite-sample coverage guarantees even for non-exchangeable data. In this paper, we show that ACI does not require the use of conformal predictors; instead, it can be implemented with the more general confidence predictors, which are computationally simpler and still maintain the crucial property of nested prediction sets. Through experiments on synthetic and real-world data, we demonstrate that confidence predictors can perform comparably to, or even better than, conformal predictors, particularly in terms of computational efficiency. These findings suggest that confidence predictors represent a viable and efficient alternative to conformal predictors in non-exchangeable data settings, although further studies are needed to identify when one method is superior.
- North America > United States (0.29)
- Europe > Sweden > Jönköping County > Jönköping (0.04)
- Europe > Sweden > Stockholm > Stockholm (0.04)
- Asia > Singapore (0.04)
AARK: An Open Toolkit for Autonomous Racing Research
Bockman, James, Howe, Matthew, Orenstein, Adrian, Dayoub, Feras
Autonomous racing demands safe control of vehicles at their physical limits for extended periods of time, providing insights into advanced vehicle safety systems which increasingly rely on intervention provided by vehicle autonomy. Participation in this field carries with it a high barrier to entry. Physical platforms and their associated sensor suites require large capital outlays before any demonstrable progress can be made. Simulators allow researches to develop soft autonomous systems without purchasing a platform. However, currently available simulators lack visual and dynamic fidelity, can still be expensive to buy, lack customisation, and are difficult to use. AARK provides three packages, ACI, ACDG, and ACMPC. These packages enable research into autonomous control systems in the demanding environment of racing to bring more people into the field and improve reproducibility: ACI provides researchers with a computer vision-friendly interface to Assetto Corsa for convenient comparison and evaluation of autonomous control solutions; ACDG enables generation of depth, normal and semantic segmentation data for training computer vision models to use in perception systems; and ACMPC gives newcomers to the field a modular full-stack autonomous control solution, capable of controlling vehicles to build from. AARK aims to unify and democratise research into a field critical to providing safer roads and trusted autonomous systems.
- Oceania > Australia (0.14)
- North America > Canada > Alberta (0.14)
- Asia > Myanmar > Tanintharyi Region > Dawei (0.04)
- Asia > Middle East > UAE (0.04)
- Leisure & Entertainment > Sports > Motorsports (1.00)
- Automobiles & Trucks (1.00)
- Transportation > Ground > Road (0.68)
Like a Martial Arts Dodge: Safe Expeditious Whole-Body Control of Mobile Manipulators for Collision Avoidance
Chen, Bingjie, Liu, Houde, Xia, Chongkun, Han, Liang, Wang, Xueqian, Liang, Bin
In the control task of mobile manipulators(MM), achieving efficient and agile obstacle avoidance in dynamic environments is challenging. In this letter, we present a safe expeditious whole-body(SEWB) control for MMs that ensures both external and internal collision-free. SEWB is constructed by a two-layer optimization structure. Firstly, control barrier functions(CBFs) are employed for a MM to establish initial safety constraints. Moreover, to resolve the pseudo-equilibrium problem of CBFs and improve avoidance agility, we propose a novel sub-optimization called adaptive cyclic inequality(ACI). ACI considers obstacle positions, velocities, and predefined directions to generate directional constraints. Then, we combine CBF and ACI to decompose safety constraints alongside an equality constraint for expectation control. Considering all these constraints, we formulate a quadratic programming(QP) as our primary optimization. In the QP cost function, we account for the motion accuracy differences between the base and manipulator, as well as obstacle influences, to achieve optimized motion. We validate the effectiveness of our SEWB control in avoiding collision and reaching target points through simulations and real-world experiments, particularly in challenging scenarios that involve fast-moving obstacles. SEWB has been proven to achieve whole-body collision-free and improve avoidance agility, similar to a "martial arts dodge".
- Asia > China > Guangdong Province > Shenzhen (0.05)
- Asia > China > Heilongjiang Province > Harbin (0.05)
- Asia > China > Anhui Province > Hefei (0.05)
- (8 more...)
- Information Technology > Artificial Intelligence > Machine Learning (0.93)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Planning & Scheduling (0.67)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Optimization (0.66)
- Information Technology > Artificial Intelligence > Robots > Robot Planning & Action (0.46)
SoNIC: Safe Social Navigation with Adaptive Conformal Inference and Constrained Reinforcement Learning
Yao, Jianpeng, Zhang, Xiaopan, Xia, Yu, Wang, Zejin, Roy-Chowdhury, Amit K., Li, Jiachen
Reinforcement Learning (RL) has enabled social robots to generate trajectories without human-designed rules or interventions, which makes it more effective than hard-coded systems for generalizing to complex real-world scenarios. However, social navigation is a safety-critical task that requires robots to avoid collisions with pedestrians while previous RL-based solutions fall short in safety performance in complex environments. To enhance the safety of RL policies, to the best of our knowledge, we propose the first algorithm, SoNIC, that integrates adaptive conformal inference (ACI) with constrained reinforcement learning (CRL) to learn safe policies for social navigation. More specifically, our method augments RL observations with ACI-generated nonconformity scores and provides explicit guidance for agents to leverage the uncertainty metrics to avoid safety-critical areas by incorporating safety constraints with spatial relaxation. Our method outperforms state-of-the-art baselines in terms of both safety and adherence to social norms by a large margin and demonstrates much stronger robustness to out-of-distribution scenarios. Our code and video demos are available on our project website: https://sonic-social-nav.github.io/.
Ancestral Causal Inference
Constraint-based causal discovery from limited data is a notoriously difficult challenge due to the many borderline independence test decisions. Several approaches to improve the reliability of the predictions by exploiting redundancy in the independence information have been proposed recently. Though promising, existing approaches can still be greatly improved in terms of accuracy and scalability. We present a novel method that reduces the combinatorial explosion of the search space by using a more coarse-grained representation of causal information, drastically reducing computation time. Additionally, we propose a method to score causal predictions based on their confidence. Crucially, our implementation also allows one to easily combine observational and interventional data and to incorporate various types of available background knowledge. We prove soundness and asymptotic consistency of our method and demonstrate that it can outperform the state-ofthe-art on synthetic data, achieving a speedup of several orders of magnitude. We illustrate its practical feasibility by applying it to a challenging protein data set.
- Europe > Netherlands > North Holland > Amsterdam (0.04)
- Europe > Germany > Brandenburg > Potsdam (0.04)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.04)
- (2 more...)