Event-Based Control via Sparsity-Promoting Regularization: A Rollout Approach with Performance Guarantees
Shumpei Nishida, Kunihisa Okano
TL;DR
The work tackles sparse intermittent actuation in linear systems by balancing infinite-horizon performance with actuation rate through a rollout-based co-design. It constructs a discounted-cost surrogate with a base periodic policy, performs $h$-step lookahead to compute online control and triggering decisions, and proves a performance bound relative to the optimal periodic strategy plus mean-square stability. Theoretical guarantees include a finite-gap bound $J^a(\mu^{u,\text{ro}},\mu^{\delta,\text{ro}})\le J^a(\mu^{u,\text{per}},\mu^{\delta,\text{per}})+1/h}$ and mean-square stability, supported by ergodicity results for the induced Markov chain. A numerical example demonstrates favorable trade-offs against periodic control and an $\ell_1$-relaxed MPC baseline, highlighting the practical impact for networked and resource-constrained control systems.
Abstract
This paper presents a controller design framework aiming to balance control performance and actuation rate. Control performance is evaluated by an infinite-horizon average cost, and the number of control actions is penalized via sparsity-promoting regularization. Since the formulated optimal control problem has a combinatorial nature, we employ a rollout algorithm to obtain a tractable suboptimal solution. In the proposed scheme, actuation timings are determined through a multistage minimization procedure based on a receding-horizon approach, and the corresponding control inputs are computed online. We establish theoretical performance guarantees with respect to periodic control and prove the stability of the closed-loop system. The effectiveness of the proposed method is demonstrated through a numerical example.
