Interpolation Conditions for Data Consistency and Prediction in Noisy Linear Systems
Martina Vanelli, Nima Monshizadeh, Julien M. Hendrickx
TL;DR
This paper presents an interpolation-based data-driven framework for noisy discrete-time LTI systems with known input matrix $B$ and unknown state matrix $A$, under a bound on energy growth $L$ and bounded process-noise energy. By deriving necessary and sufficient interpolation conditions via PSD completions, the authors obtain SDP formulations for data-consistency verification and for inferring minimal noise or energy amplification compatible with observed data. They show that the one-step-ahead feasible state set $\mathcal{X}_+(u)$ is an ellipsoid in the noise-free case and a union of ellipsoids when noise is present, enabling safety verification and worst-case energy minimization. The approach provides a principled path toward data-driven control without explicit system identification and suggests extensions to multi-step predictions and nonlinear dynamics.
Abstract
We develop an interpolation-based framework for noisy linear systems with unknown system matrix with bounded norm (implying bounded growth or non-increasing energy), and bounded process noise energy. The proposed approach characterizes all trajectories consistent with the measured data and these prior bounds in a purely data-driven manner. This characterization enables data-consistency verification, inference, and one-step ahead prediction, which can be leveraged for safety verification and cost minimization. Ultimately, this work represents a preliminary step toward exploiting interpolation conditions in data-driven control, offering a systematic way to characterize trajectories consistent with a dynamical system within a given class and enabling their use in control design.
