A finite-sample bound for identifying partially observed linear switched systems from a single trajectory
Daniel Racz, Mihaly Petreczky, Balint Daroczy
TL;DR
This work addresses identifying Linear Switched Systems (LSS) from a single observed trajectory by estimating Markov parameters and applying a reduced-basis Ho-Kalman realization. It proves a finite-sample probabilistic bound on the parameter estimation error under quadratic stability, leveraging concentration results for weakly dependent processes. The main result shows an $O(1/\sqrt{N})$ convergence rate for the Frobenius-norm error in the recovered system matrices, with high-probability guarantees that improve as the sample size grows. This provides a practical consistency guarantee for using Ho-Kalman-based identification on LSSs from a single long sequence, informing sample complexity and design of the reduced-basis Hankel approach for control-oriented modeling.
Abstract
We derive a finite-sample probabilistic bound on the parameter estimation error of a system identification algorithm for Linear Switched Systems. The algorithm estimates Markov parameters from a single trajectory and applies a variant of the Ho-Kalman algorithm to recover the system matrices. Our bound guarantees statistical consistency under the assumption that the true system exhibits quadratic stability. The proof leverages the theory of weakly dependent processes. To the best of our knowledge, this is the first finite-sample bound for this algorithm in the single-trajectory setting.
