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

In this chapter we study the robust stability independent of delay of some class of uncertain quasipolynomials, whose coefficients may vary in a certain prescribed range. OUr main contributions include frequency-sweeping conditions for interval, diamond and spherical quasipolynomial families. The correspoding results provide necessary and sufficient conditions, and are easy to check, requiring only the computation of two simple frequency-dependent functions. Various extensions (polytopic uncertainty, multivariate polynomials) are also presented.

Robust Stability Conditions of Quasipolynomials by Frequency Sweeping

In order to generate high accuracy data for space-borne Synthetic Aperture Radar (SAR) image interpretation, a novel parallel SAR echo generation approach is proposed in this paper. Target's backscattering coefficient is variable at the condition of wide bandwidth and large aspect angle. Considering targets' space-variant and time-variant backscattering, electromagnetic scattering at arbitrary aspect angle and frequency point is calculated accurately by Finite Difference Time Domain (FDTD). However, FDTD is a time-domain method causing large computation load, thus a parallel processing scheme is designed to reduce simulation time. It was observed that proposed approach provided higher image quality compared to classical method, and parallel scheme was also verified effective in the experiment.

High accuracy SAR echo generation approach using space-time-variant backscattering characteristics

In this paper we provide alternative proofs for the classical Bode and Poisson type sensitivity integrals and their extensions for both continuous-time and discrete-time systems. Our derivation uses the well-known properties of Laplace and Z-transforms. This derivation helps establish a connection between Bode and Poisson type sensitivity integrals and Laplace and Z-transforms, hence providing an alternative perspective in interpreting these fundamental integral results.

Sensitivity integrals and transformation techniques: a new perspective

The vertical electron density distribution can have a significant impact on ionospheric measurements of Total Electron Content (TEC) derived from estimates of Faraday rotation (FR) with spaceborne low-frequency SAR data. Using vertical electron density data and the IGRF-12 magnetic field model, simulations of FR under different vertical electron density distributions for an L-band SAR have been performed. The usual approximation that the geometric and magnetic field parameters can be estimated at 400 km when converting FR to TEC is shown to cause significant errors, especially for regions at low latitude and near the zero FR line.

Impact of vertical electron density distribution on ionospheric total electron content measurements based on spaceborne low-frequency SAR

ScanSAR images are widely used in both military and civil fields with the capability of wide swath. However, the scalloping effect seriously affects the quality of scanSAR images, especially in the complex scenes, e.g. the sea-land junction scene. This paper presents a modified Kalman-filter method for scalloping suppression. First, the scanSAR image model is built, considering the scalloping effect and noise. Then, Kalman filter is adopted for suppressing the scalloping effect. Moreover, pre-processing method, on the basis of image statistical characteristics, is implemented to accommodate complex scene. Specifically, the pre-processing, involving image segmentation and brightness filling, divides the image into sub-images with different brightness and provides linear-Gaussian condition for Kalman filter through brightness filling. Finally, the method is verified by GaoFen-3(GF-3) SAR images, with the discussion and conclusion.

Jie Chen

Papers

Robust Stability Conditions of Quasipolynomials by Frequency Sweeping

High accuracy SAR echo generation approach using space-time-variant backscattering characteristics

Sensitivity integrals and transformation techniques: a new perspective

Impact of vertical electron density distribution on ionospheric total electron content measurements based on spaceborne low-frequency SAR

A Modified Kalman-Filter Method for Scalloping Suppression with Gaofen-3 SAR Images