Recent Advances on Linear Control Theory under Communication Constraints: A Survey (original) (raw)
2007 46th IEEE Conference on Decision and Control, 2007
We study the problem of distributed stabilization of linear systems over communication channels. Building on our earlier work, we adopt an information theoretic look at the signaling problem when the system and observations are noisy. We provide a lower bound on the average sum-rate, which is tight when the system noise is absent. We further show that when the system and observations are noisy, the signaling process involves coding over an unknown channel with unequal side information between the stations, and as such its construction is fairly complicated. This leads to new insights on designing distributed controllers connected over channels.
Stabilization of Networked Multi-Input Systems With Channel Resource Allocation
IEEE Transactions on Automatic Control, 2000
In this paper, we study the problem of stabilizing a linear time-invariant discretetime system with information constraints in the input channels. The information constraint in each input channel is modelled as a sector uncertainty. Equivalently, the transmission error of an input channel is modelled as an additive system uncertainty with a bound in the induced norm. We attempt to find the least information required, or equivalently the largest allowable uncertainty bound, in each input channel which renders the stabilization possible. The solution for the single-input case, which gives a typical H ∞ optimal control problem, is available in the literature and is given analytically in terms of the Mahler measure or topological entropy of the plant. The main purpose of this paper is to address the multi-input case. In the multi-input case, if the information constraint in each input channel is given a priori, then our stabilization problem turns out to be a so-called µ synthesis problem, a notoriously hard problem. In this paper, we assume that the information constraints in the input channels are determined by the network resources assigned to the channels and they can be allocated subject to a total recourse constraint. With this assumption, the resource allocation becomes part of the design problem and a modified µ synthesis problem arises. Surprisingly, this modified µ-synthesis problem can be solved analytically and the solution is also given in terms of the Mahler measure or topological entropy as in the single-input case.
New Trends in Networked Control of Complex Dynamic Systems: Theories and Applications
Mathematical Problems in Engineering, 2014
In recent years, networked control systems (NCSs) have been extensively studied in both academy and industry and used in many fields, such as telerobotics, smart grids, intelligent transportation systems, and even in medical, military, and aerospace applications. NCSs offer great advantages, such as low cost, high reliability, simple installation and maintenance, and reduced weight and power requirements. In the meantime, the common shortcomings of the communication networks, such as transmission delays, packets drops and disorder, and data quantization, also appeared in the loops of the networked systems. During past decade, plenty of studies have been carried out in the literature to address the networkinduced problems for given dynamic systems that are relatively simple. However, more challenging mathematical problems such as network-based control of more complex dynamics, including time delay, parameter variations, uncertainties, and nonlinearities, are still largely open and necessitate further investigations to enable wider and more successful applications. This special issue aims to provide a timely discussion on the trends and challenges of networked control of complex dynamics systems. Both theoretical and application-oriented papers are sought for, addressing the issues and mathematical techniques of network-based control, sensing, multiagent control of complex dynamic systems, and so forth.
Stable Networked Control Systems With Bounded Control Authority
IEEE Transactions on Automatic Control, 2012
We study the stability of a class of networked control systems with hard bounds on the control authority. The plant dynamics are discrete-time, linear, and time-invariant, with stochastic process noise and measurement noise. The controller is designed as a norm-bounded causal history-dependent function of the past outputs perturbed by bounded noise. The resulting control signals are assumed to be transmitted through a lossy channel with packet dropouts. We show that under mild assumptions on the system matrices, the statistics of the process and measurement noise sequences, and the probability of dropouts, it is possible to ensure bounded variance of the system in closed-loop.
Inherent issues in networked control systems: a survey
2004
Due to major advancements in the area of networking over the past decade, a new paradigm of control systems has emerged, namely networked control systems. Such systems differ from classical control systems in that their control loops are closed around communication networks. Thus, the need for new stability and performance guarantees arises. In this paper, we aim to shed some
A Survey of Recent Results in Networked Control Systems
Proceedings of The IEEE, 2007
Networked Control Systems (NCSs) are spatially distributed systems for which the communication between sensors, actuators, and controllers is supported by a shared communication network. In this paper we review several recent results on estimation, analysis, and controller synthesis for NCSs. The results surveyed address channel limitations in terms of packet-rates, sampling, network delay and packet dropouts. The results are presented in a tutorial fashion, comparing alternative methodologies.
Journal of Systems Science and Complexity, 2011
This paper addresses a robust stabilization problem of a class of uncertain nonlinear systems using output measurements via a finite data-rate communication channel. The authors assumes that there exist an observer and a control law for the systems in the absence of any finite data-rate communication channel. Based on the observer and the control law, the authors constructs an encoder/decoder pair and provides a sufficient condition, including suitable sampling period and data rate, which will guarantee the stability of the closed-loop systems when a finite data-rate communication channel is introduced.
Rate-Limited Stabilization for Network Control Systems
2007 American Control Conference, 2007
In this paper, we extend results from packet-based control theory, and present sufficient conditions on the rate of a packet network to guarantee asymptotic stability of unstable discrete LTI system, with less inputs than states. Two types of Network Control Systems are considered in the absence of communication delays, then for one of the two types, the case of a constant time delay is discussed. Examples and simulations are provided to demonstrate the results.
Optimal controller design for networked control systems
… of the 17th IFAC world congress, 2008
This paper addresses the problem of optimal control system design for networked control systems. We focus on a situation where the plant is single-input single-output and the communication link between the controller and the plant is signal-to-noise ratio constrained. In this setting, we characterize the controllers that minimize the tracking error variance, while respecting the channel signal-to-noise ratio constraint. We also provide a description of the optimal tradeoff curve in the performance versus signal-to-noise ratio plane and, as a byproduct, we establish easily computable bounds on the achievable performance. We illustrate our results with a numerical example based on a bit rate limited channel.