Stabilization of systems with asynchronous sensors and controllers

Abstract

We study the stabilization of networked control systems with asynchronous sensors and controllers.Offsets between the sensor and controller clocks are unknown and modeled as parametric uncertainty.First we consider multi-input linear systems and provide a sufficient condition for the existence of linear time-invariant controllers that are capable of stabilizing the closed-loop system for every clock offset in a given range of admissible values. For first-order systems, we next obtain the maximum length of the offset range for which the system can be stabilized by a single controller. Finally, this bound is compared with the offset bounds that would be allowed if we restricted our attention to static output feedback controllers.

Stability analysis for systems with asynchronous sensors and actuators

“…Then (20) cannot hold if there is not m = (b/n 2 ) ∈ N such that a = mn 2 , which proves the second part in (19). Moreover, if a = mn 2 with m ∈ N then τ 1 (aT 2 ) = τ 1 (mn 2 T 2 ) = τ 1 (mn 1 T 1 ) and then τ 1 (aT 2 ) =τ 1 , which terminates the proof.…”

“…As pointed out in [19], in real applications we can encounter situations where the local clocks at the sensor and at the actuator are not synchronized. As mentioned there, clocks synchronization over networks has fundamental limitations [8] and GPS synchronization may be vulnerable against malicious attacks [12].…”

“…As mentioned there, clocks synchronization over networks has fundamental limitations [8] and GPS synchronization may be vulnerable against malicious attacks [12]. In this context [19] addresses the problem of how large the clock offset between actuator and sensor can be, without compromising the existence of a stabilizing linear time-invariant controller.…”

Separation Principle for Linear Sampled-Data Control Systems Under Observer-Based Output Feedback With Aperiodic Sampling

“…observer [21], a sampled-data observer [3], [5]- [7], and a continuous-discrete observer [4]. Among them, [7], [21] introduced simple design strategies under the separation principle.…”

${L}_{2}$-Stability Criterion for Systems with Decentralized Asynchronous Controllers

“…Although the problem considered in this paper is novel, stability analysis methods have been proposed for centralized x controllers subjected to sampling and asynchronism between sensors and actuators [7,8,9]. However, the period between sampling and actuation instants was treated to be constant and all the system state data was considered to be sampled at same time instants.…”