Data-Driven Output-Based Approach to the Output Regulation Problem of Unknown Linear Systems via Value Iteration
Haoyan Lin, Jie Huang
TL;DR
The paper addresses output regulation for unknown linear systems by developing a data-driven, value-iteration framework. It introduces a novel output-feedback control law that avoids explicit dependence on the observer gain and reduces the problem to a state-feedback design for an augmented auxiliary system, enabling VI-based learning. A key contribution is the systematic VI-based method to solve the augmented-LQR problem with relaxed solvability conditions and reduced unknowns, plus a rigorous link between state- and output-feedback LQR in the augmented setting. Numerical examples demonstrate convergence and effective tracking for both E=0 and E≠0 scenarios, highlighting the approach's practicality for stabilizable-but-not-controllable plants in a model-free, data-driven setting.
Abstract
The output regulation problem for unknown linear systems has been studied using state-based and output-based internal model approaches in the special case with no disturbances. This paper further investigates the output regulation problem for unknown linear systems using a data-driven output-based approach via value iteration. For this purpose, we first develop a novel output-feedback control law that does not explicitly rely on the observer gain to solve the output regulation problem. We then show that the data-driven approach for designing an output-feedback control law for the given plant can be reduced to the data-driven design of a state-feedback control law for a well-defined augmented auxiliary system. As a result, we develop a systematic data-driven approach to solve the output regulation problem for unknown linear systems via value iteration. Finally, we establish a relation between the data-driven state-feedback control law and the data-driven output-feedback control law in the LQR sense.
