There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Preface, Notations 1.Introduction to Time-Delay Systems I.Frequency-Domain Approach 2.Systems with Commensurate Delays 3.Systems withIncommensurate Delays 4.Robust Stability Analysis II.Time Domain Approach 5.Systems with Single Delay 6.Robust Stability Analysis 7.Systems with Multiple and Distributed Delays III.Input-Output Approach 8.Input-output stability A.Matrix Facts B.LMI and Quadratic Integral Inequalities Bibliography Index

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Stability of Time-Delay Systems

There is an increasing demand for dynamic systems to become safer and more reliable This requirement extends beyond the normally accepted safety-critical systems such as nuclear reactors and aircraft, where safety is of paramount importance, to systems such as autonomous vehicles and process control systems where the system availability is vital It is clear that fault diagnosis is becoming an important subject in modern control theory and practice Robust Model-Based Fault Diagnosis for Dynamic Systems presents the subject of model-based fault diagnosis in a unified framework It contains many important topics and methods; however, total coverage and completeness is not the primary concern The book focuses on fundamental issues such as basic definitions, residual generation methods and the importance of robustness in model-based fault diagnosis approaches In this book, fault diagnosis concepts and methods are illustrated by either simple academic examples or practical applications The first two chapters are of tutorial value and provide a starting point for newcomers to this field The rest of the book presents the state of the art in model-based fault diagnosis by discussing many important robust approaches and their applications This will certainly appeal to experts in this field Robust Model-Based Fault Diagnosis for Dynamic Systems targets both newcomers who want to get into this subject, and experts who are concerned with fundamental issues and are also looking for inspiration for future research The book is useful for both researchers in academia and professional engineers in industry because both theory and applications are discussed Although this is a research monograph, it will be an important text for postgraduate research students world-wide The largest market, however, will be academics, libraries and practicing engineers and scientists throughout the world

Robust Model-Based Fault Diagnosis for Dynamic Systems

Networked control systems (NCSs) are spatially distributed systems for which the communication between sensors, actuators, and controllers is supported by a shared communication network. 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

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A Survey of Recent Results in Networked Control Systems

1. Introduction. 2. Linear Algebra. 3. Linear Systems. 4. H2 and Ha Spaces. 5. Internal Stability. 6. Performance Specifications and Limitations. 7. Balanced Model Reduction. 8. Uncertainty and Robustness. 9. Linear Fractional Transformation. 10. m and m- Synthesis. 11. Controller Parameterization. 12. Algebraic Riccati Equations. 13. H2 Optimal Control. 14. Ha Control. 15. Controller Reduction. 16. Ha Loop Shaping. 17. Gap Metric and ...u- Gap Metric. 18. Miscellaneous Topics. Bibliography. Index.

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Essentials of Robust Control

This note studies the optimal tracking problem for linear time-invariant single-input-multiple-output systems responding to a step reference signal. An integral square error criterion is used as the measure for tracking performance. Explicit expressions are developed for the optimal tracking error. These results characterize how nonsquare plants may pose additional difficulties for tracking, other than those resulted from nonminimum phase zeros and unstable poles.

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Optimal tracking performance for SIMO systems

In this paper, we study the consensus problem for second-order heterogeneous multi-agent systems under a directed graph. Unlike the existing consensus algorithms for second-order multi-agent systems in which all agents are assumed to have common unit inertias or share common control gains, we allow the inertias and the control gains to be heterogeneous for each agent. Fully distributed consensus algorithms are proposed when there exist, respectively, absolute velocity damping and relative velocity damping. Moreover, an adaptive σ-modification scheme for the gain adaption is proposed, which renders smaller control gains and thus requires smaller amplitude on the control input without sacrificing the consensus convergence.

Consensus of second-order heterogeneous multi-agent systems under a directed graph

Studies stability properties of linear time-invariant delay systems. The authors consider specifically the notion of asymptotic stability independent of delays. Systems with both commensurate and non-commensurate delays are investigated. The authors present for each case a necessary and sufficient condition, and further they demonstrate how these conditions may be extended readily to study asymptotic stability independent of delays for uncertain systems. These conditions can be readily checked, and they appear to be considerably simpler than results developed elsewhere previously.

Asymptotic stability independent of delays: simple necessary and sufficient conditions

This paper studies the optimal tracking performance of multiple-input multiple-output (MIMO), finite dimensional, linear time-invariant discrete-time systems with a power-constrained additive white noise (AWN) channel in the feedback path. We adopt the tracking error power as a measure of the performance and examine the best achievable performance by all two-parameter stabilizing controllers. In the due process, a scaling scheme is introduced as a means of integrating controller and channel design, and is optimized to better the tracking performance. In contrast to the standard setting where tracking of a step reference signal is conducted with no communication constraint, in which the tracking error can be made as zero for minimum phase plants, it is shown explicitly herein that the tracking performance will be additionally constrained by the plant unstable poles, as a consequence of noisy, power-constrained channels in the feedback loop.

Optimal tracking performance of discrete-time systems over an additive white noise channel

Recently, several magnetic tunnel junction (MTJ)-based non-volatile ternary content-addressable memory (NV-TCAM) cells have been proposed to realize zero standby power. However, they still suffer from low reliability and high power consumption during search operations. To address these issues, we propose a novel MTJ-based NV-TCAM cell, which is composed of 15 transistors and 4 MTJs (15T-4MTJ). By utilizing the differential MTJs with complementary states and positive feedback of cross-coupled inverters for sensing, the proposed 15T-4MTJ NV-TCAM cell can significantly improve the search reliability. Moreover, owing to that there is no static current during search operations, only dynamic charging and discharging current, it can achieve ultra-low power consumption. In addition, by using only one transistor as the critical path between the match-line and GND, its switch delay can be shortened, thereby realizing high-speed search operations. Hybrid CMOS/MTJ simulation results of the 144-bit word circuit show that the proposed 15T-4MTJ NV-TCAM cell can obtain a smaller search error rate of 2.7%, a higher search speed of 0.17 ns, and a lower search energy of 0.17 fJ/bit/search in comparison with other MTJ-based NV-TCAM cells. On the other hand, its write energy of 1.589 pJ/bit is about $3.64\times $ smaller than that of the previously proposed 10T-4MTJ NV-TCAM cell.

Jie Chen

Papers

Optimal tracking performance for SIMO systems

Consensus of second-order heterogeneous multi-agent systems under a directed graph

Asymptotic stability independent of delays: simple necessary and sufficient conditions

Optimal tracking performance of discrete-time systems over an additive white noise channel

A Novel MTJ-Based Non-Volatile Ternary Content-Addressable Memory for High-Speed, Low-Power, and High-Reliable Search Operation