76 citations · 213 across the 52 of their papers we have counts for
64 papers
Online, Reachability-Aware, Sampling-Based Motion Planning
Brendan Gould, Zhiyuan Zhang, Panagiotis Tsiotras +1
Sampling-Based Model-Predictive Control (MPC) algorithms are a flexible class of controllers used for navigation on a wide range of robotic systems. Historically, such approaches h…
Efficient Interaction-Aware Interval Analysis of Neural Network Feedback Loops
Saber Jafarpour, Akash Harapanahalli, Samuel Coogan
In this paper, we propose a computationally efficient framework for interval reachability of systems with neural network controllers. Our approach leverages inclusion functions for…
A Toolbox for Fast Interval Arithmetic in numpy with an Application to Formal Verification of Neural Network Controlled Systems
Akash Harapanahalli, Saber Jafarpour, Samuel Coogan
In this paper, we present a toolbox for interval analysis in numpy, with an application to formal verification of neural network controlled systems. Using the notion of natural inc…
GreenEVT: Greensboro Electric Vehicle Testbed
Gustav Nilsson, Alejandro D. Owen Aquino, Samuel Coogan +1
The ongoing electrification of the transportation fleet will increase the load on the electric power grid. Since both the transportation network and the power grid already experien…
Contraction-Guided Adaptive Partitioning for Reachability Analysis of Neural Network Controlled Systems
Akash Harapanahalli, Saber Jafarpour, Samuel Coogan
In this paper, we present a contraction-guided adaptive partitioning algorithm for improving interval-valued robust reachable set estimates in a nonlinear feedback loop with a neur…
Interval Reachability of Nonlinear Dynamical Systems with Neural Network Controllers
Saber Jafarpour, Akash Harapanahalli, Samuel Coogan
This paper proposes a computationally efficient framework, based on interval analysis, for rigorous verification of nonlinear continuous-time dynamical systems with neural network…
Monotonicity and Contraction on Polyhedral Cones
Saber Jafarpour, Samuel Coogan
In this note, we study monotone dynamical systems with respect to polyhedral cones. Using the half-space representation and the vertex representation, we propose three equivalent c…
Robust Training and Verification of Implicit Neural Networks: A Non-Euclidean Contractive Approach
Saber Jafarpour, Alexander Davydov, Matthew Abate +2
This paper proposes a theoretical and computational framework for training and robustness verification of implicit neural networks based upon non-Euclidean contraction theory. The…
Safe Schedule Verification for Urban Air Mobility Networks with Node Closures
Qinshuang Wei, Gustav Nilsson, Samuel Coogan
In Urban Air Mobility (UAM) networks, takeoff and landing sites, called vertiports, are likely to experience intermittent closures due to, e.g., adverse weather. To ensure safety,…
Leveraging Heterogeneous Capabilities in Multi-Agent Systems for Environmental Conflict Resolution
Michael Enqi Cao, Jonas Warnke, Yunhai Han +3
In this paper, we introduce a high-level controller synthesis framework that enables teams of heterogeneous agents to assist each other in resolving environmental conflicts that ap…
Comparative Analysis of Interval Reachability for Robust Implicit and Feedforward Neural Networks
Alexander Davydov, Saber Jafarpour, Matthew Abate +2
We use interval reachability analysis to obtain robustness guarantees for implicit neural networks (INNs). INNs are a class of implicit learning models that use implicit equations…
Resilience of Input Metering in Dynamic Flow Networks
Saber Jafarpour, Samuel Coogan
In this paper, we study robustness of input metering policies in dynamic flow networks in the presence of transient disturbances and attacks. We consider a compartmental model for…
Safe Learning for Uncertainty-Aware Planning via Interval MDP Abstraction
Jesse Jiang, Ye Zhao, Samuel Coogan
We study the problem of refining satisfiability bounds for partially-known stochastic systems against planning specifications defined using syntactically co-safe Linear Temporal Lo…
Robustness Certificates for Implicit Neural Networks: A Mixed Monotone Contractive Approach
Saber Jafarpour, Matthew Abate, Alexander Davydov +2
Implicit neural networks are a general class of learning models that replace the layers in traditional feedforward models with implicit algebraic equations. Compared to traditional…
Sensitivity to User Mischaracterizations in Electric Vehicle Charging
Cesar Santoyo, Gustav Nilsson, Samuel Coogan
In this paper, we consider electric vehicle charging facilities that offer various levels of service for varying prices such that rational users choose a level of service that mini…
The Strong Integral Input-to-State Stability Property in Dynamical Flow Networks
Gustav Nilsson, Samuel Coogan
Dynamical flow networks serve as macroscopic models for, e.g., transportation networks, queuing networks, and distribution networks. While the flow dynamics in such networks follow…
Run Time Assurance for Safety-Critical Systems: An Introduction to Safety Filtering Approaches for Complex Control Systems
Kerianne Hobbs, Mark Mote, Matthew Abate +2
Run Time Assurance (RTA) Systems are online verification mechanisms that filter an unverified primary controller output to ensure system safety. The primary control may come from a…
Capacity-Constrained Urban Air Mobility Scheduling
Qinshuang Wei, Gustav Nilsson, Samuel Coogan
This paper studies the problem of scheduling urban air mobility trips when travel times are uncertain and capacity at destinations is limited. Urban air mobility, in which air tran…
Model Free Barrier Functions via Implicit Evading Maneuvers
Eric Squires, Rohit Konda, Samuel Coogan +1
This paper demonstrates that the safety override arising from the use of a barrier function can in some cases be needlessly restrictive. In particular, we examine the case of fixed…
On the Impact of the Capacity Drop Phenomenon for Freeway Traffic Flow Control
Michael Enqi Cao, Gustav Nilsson, Samuel Coogan
Capacity drop is an empirically observed phenomenon in vehicular traffic flow on freeways whereby, after a critical density is reached, a state of congestion sets in, but the freew…
A Numerical Method to Compute Stability Margins of Switching Linear Systems
Corbin Klett, Matthew Abate, Samuel Coogan +1
Stability margins for linear time-varying (LTV) and switched-linear systems are traditionally computed via quadratic Lyapunov functions, and these functions certify the stability o…
Safety With Limited Range Sensing Constraints For Fixed Wing Aircraft
Eric Squires, Rohit Konda, Pietro Pierpaoli +2
In this paper we discuss how to use a barrier function that is subject to kinematic constraints and limited sensing in order to guarantee that fixed wing unmanned aerial vehicles (…
Improving the Fidelity of Mixed-Monotone Reachable Set Approximations via State Transformations
Matthew Abate, Samuel Coogan
Mixed-monotone systems are separable via a decomposition function into increasing and decreasing components, and this decomposition function allows for embedding the system dynamic…
Resource Aware Pricing for Electric Vehicle Charging
Cesar Santoyo, Gustav Nilsson, Samuel Coogan
Electric vehicle charging facilities offer electric charge and parking to users for a fee. Both parking availability and electric charge capacity are constrained resources, and as…