This paper studies a number of quantized feedback design problems for linear systems. We consider the case where quantizers are static (memoryless). The common aim of these design problems is to stabilize the given system or to achieve certain performance with the coarsest quantization density. Our main discovery is that the classical sector bound approach is nonconservative for studying these design problems. Consequently, we are able to convert many quantized feedback design problems to well-known robust control problems with sector bound uncertainties. In particular, we derive the coarsest quantization densities for stabilization for multiple-input-multiple-output systems in both state feedback and output feedback cases; and we also derive conditions for quantized feedback control for quadratic cost and H/sub /spl infin// performances.

The sector bound approach to quantized feedback control | NOVA. The University of Newcastle's Digital Repository

This paper is concerned with the distributed H∞ filtering problem for a class of discrete-time Markovian jump nonlinear time-delay systems with deficient statistics of mode transitions. The system measurements are collected through a lossy sensor network subject to randomly occurring quantization errors and randomly occurring packet dropouts. The description of deficient statistics of mode transitions that account for known, unknown, and uncertain transition probabilities is comprehensive. A distributed filter design scheme is outlined by explicitly characterizing the filter gains in terms of some matrix inequalities. Simulation results demonstrate the effectiveness of the proposed filtering scheme.

Distributed H ∞ Filtering for a Class of Markovian Jump Nonlinear Time-Delay Systems Over Lossy Sensor Networks

A networked control system (NCS) is a control system which involves a communication network. In NCSs, the continuous-time measurement is usually sampled and quantized before transmission. Then, the measurement is transmitted to the remote controller via the communication channel, during which the signal may be delayed, lost or even sometimes not allowed for transmission due to the communication or energy constraints. In recent years, the modeling, analysis and synthesis of networked control systems (NCSs) have received great attention, which leads to a large number of publications. This paper attempts to present an overview of recent advances and unify them in a framework of network-induced issues such as signal sampling, data quantization, communication delay, packet dropouts, medium access constraints, channel fading and power constraint, and present respective solution approaches to each of these issues. We draw some conclusions and highlight future research directions in end.

Analysis and synthesis of networked control systems: A survey of recent advances and challenges.

This paper addresses the robust H∞ filtering problem for a class of discrete time-varying Markovian jump systems with randomly occurring nonlinearities and sensor saturation. Two kinds of transition probability matrices for the Markovian process are considered, namely, the one with polytopic uncertainties and the one with partially unknown entries. The nonlinear disturbances are assumed to occur randomly according to stochastic variables satisfying the Bernoulli distributions. The main purpose of this paper is to design a robust filter, over a given finite-horizon, such that the H∞ disturbance attenuation level is guaranteed for the time-varying Markovian jump systems in the presence of both the randomly occurring nonlinearities and the sensor saturation. Sufficient conditions are established for the existence of the desired filter satisfying the H∞ performance constraint in terms of a set of recursive linear matrix inequalities. Simulation results demonstrate the effectiveness of the developed filter design scheme.

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Robust ${{\cal H}}_{\infty}$ Filtering for Markovian Jump Systems With Randomly Occurring Nonlinearities and Sensor Saturation: The Finite-Horizon Case

In the framework of the networked control systems (NCSs), the components are connected with each other over a shared band-limited network. The merits of NCSs include easy extensibility, resource sh...

A survey on sliding mode control for networked control systems

Output-feedback control design for NCSs subject to quantization and dropout

Sliding mode control for stochastic systems subject to packet losses

This paper considers the H∞ control problem of networked control systems, respectively, for the two cases that system state is available and unavailable. It is assumed that there exists a communication network in the feedback loop, and multiple data packet dropouts may happen. An estimation method is introduced to compensate the lost data. And then, the design of H∞ control is considered for the states available and states unavailable, respectively, and some sufficient conditions are derived such that the closed-loop systems are exponentially mean-square stable with prescribed H∞ disturbance attenuation level.

H∞ control for networked systems with data packet dropout

This paper considers the problem of sliding mode control for a class of uncertain switched systems with parameter uncertainties and external disturbances. A key feature of the controlled system is that each subsystem is not required to share the same input channel, which was usually assumed in some existing works. By means of a weighted sum of the input matrix, a common sliding surface is designed in this work. It is shown that the reachability of the sliding surface can be ensured by the present sliding mode controller. Moreover, the sliding motion on the specified sliding surface is asymptotically stable under the proposed switching signal dependent on the state and time. Additionally, the above results are further extended to the case that the system states are unavailable. Both the sliding surface and sliding mode controller are designed by utilising state-observer. Finally, numerical simulation examples are given to illustrate the effectiveness of the present method.

Design of sliding mode control for a class of uncertain switched systems

This article investigates the problem of stabilising predictive control for constrained systems, wherein communication from the controller to the plant input is through a digital channel subject to quantisation and delay. A novel model with structured norm-bounded uncertainties is proposed to describe control system with input quantisation. Under a multirate scheme, a delay compensation strategy is presented. The networked predictive control synthesis approach is developed by solving a finite receding horizon optimisation problem with free control moves. It is shown that the proposed predictive controller not only efficiently reduces the negative effects of the quantisation and communication delays but also guarantees the closed-loop stability and satisfies constraints. Finally, a simulation example illustrates the effectiveness of the derived method.

Tinggang Jia

Papers

Output-feedback control design for NCSs subject to quantization and dropout

Sliding mode control for stochastic systems subject to packet losses

H∞ control for networked systems with data packet dropout

Design of sliding mode control for a class of uncertain switched systems

Networked predictive control of constrained linear systems with input quantisation