Underapproximate Reachability Analysis for a Class of Linear Systems With Inputs
Mohamed Serry, Jun Liu · IEEE Transactions on Automatic Control · 2023
Underapproximations of reachable sets and tubes have been receiving growing research attention due to their important roles in control synthesis and verification. Available underapproximation methods applicable to continuous-time linear systems typically assume the ability to compute transition matrices and their integrals exactly, which is not feasible in general, and/or suffer from high computational costs. In this note, we attempt to overcome these drawbacks for a class of linear time-invariant (LTI) systems, where we propose a novel method to underapproximate finite-time forward reachable sets and tubes, utilizing approximations of the matrix exponential and its integral. In particular, we consider the class of continuous-time LTI systems with an identity input matrix and initial and input values belonging to full-dimensional sets that are affine transformations of closed unit balls. The proposed method yields computationally efficient underapproximations of reachable sets and tubes, when implemented using zonotopes, with first-order convergence guarantees in the sense of the Hausdorff distance. To illustrate its performance, we implement our approach in three numerical examples, where linear systems of dimensions ranging between 2 and 200 are considered.