Andrew J. Fleming

Bio: Andrew J. Fleming is an academic researcher from University of Newcastle. The author has contributed to research in topics: Piezoelectricity & Scanning probe microscopy. The author has an hindex of 44, co-authored 254 publications receiving 6849 citations. Previous affiliations of Andrew J. Fleming include Newcastle College & University of Stuttgart.

Piezoelectric Transducers for Vibration Control and Damping

Abstract: Fundamentals of Piezoelectricity- Feedback Control of Structural Vibration- Piezoelectric Shunt Damping- Feedback Structure of Piezoelectric Shunt Damping Systems- Instrumentation- Multi-port Shunts- Adaptive Shunt Damping- Negative Capacitor Shunt Impedances- Optimal Shunt Synthesis- Dealing with Hysteresis- Nanopositioning

A review of nanometer resolution position sensors: Operation and performance

Abstract: Position sensors with nanometer resolution are a key component of many precision imaging and fabrication machines. Since the sensor characteristics can define the linearity, resolution and speed of the machine, the sensor performance is a foremost consideration. The first goal of this article is to define concise performance metrics and to provide exact and approximate expressions for error sources including non-linearity, drift and noise. The second goal is to review current position sensor technologies and to compare their performance. The sensors considered include: resistive, piezoelectric and piezoresistive strain sensors; capacitive sensors; electrothermal sensors; eddy current sensors; linear variable displacement transformers; interferometers; and linear encoders.

A broadband controller for shunt piezoelectric damping of structural vibration

Abstract: In this paper a broadband active shunt technique for controlling vibration in piezoelectric laminated structures is proposed. The effect of the negative capacitance controller is studied theoretically and then validated experimentally on a piezoelectric laminated simply supported plate. The 'negative capacitance controller' is similar in nature to passive shunt damping techniques, as a single piezoelectric transducer is used to dampen multiple modes. While achieving comparable performance to that of the passive shunt schemes, the negative capacitance controller has a number of advantages. It is simpler to implement, less sensitive to environmental variations and can be considered as a broadband vibration absorber.

Integral resonant control of collocated smart structures

Abstract: This paper introduces integral resonant control, IRC, a simple, robust and well-performing technique for vibration control in smart structures with collocated sensors and actuators. By adding a direct feed-through to a collocated system, the transfer function can be modified from containing resonant poles followed by interlaced zeros, to zeros followed by interlaced poles. It is shown that this modification permits the direct application of integral feedback and results in good performance and stability margins. By slightly increasing the controller complexity from first to second order, low-frequency gain can be curtailed, alleviating problems due to unnecessarily high controller gain below the first mode. Experimental application to a piezoelectric laminate cantilever beam demonstrates up to 24 dB modal amplitude reduction over the first eight modes.

Sensorless vibration suppression and scan compensation for piezoelectric tube nanopositioners

Abstract: Piezoelectric tube scanners are employed in high-resolution positioning applications such as scanning probe microscopy and nanofabrication. Much research has proceeded with the aim of reducing hysteresis and vibration-the two foremost problems associated with piezoelectric tube scanners. In this paper, two simple techniques are proposed for simultaneously reducing hysteresis and vibration: 1) A new dc accurate charge amplifier is shown to significantly reduce hysteresis while avoiding characteristic voltage drift. 2) Piezoelectric shunt damping, a technique previously resident in the field of smart structures, has been applied to damp tube vibration. By attaching an LCR impedance to a single tube electrode, the first mechanical mode is reduced in magnitude by more than 20 dB.

I and i

Abstract: 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 …

Forecasting, Structural Time Series Models and the Kalman Filter

Abstract: In this book, Andrew Harvey sets out to provide a unified and comprehensive theory of structural time series models. Unlike the traditional ARIMA models, structural time series models consist explicitly of unobserved components, such as trends and seasonals, which have a direct interpretation. As a result the model selection methodology associated with structural models is much closer to econometric methodology. The link with econometrics is made even closer by the natural way in which the models can be extended to include explanatory variables and to cope with multivariate time series. From the technical point of view, state space models and the Kalman filter play a key role in the statistical treatment of structural time series models. The book includes a detailed treatment of the Kalman filter. This technique was originally developed in control engineering, but is becoming increasingly important in fields such as economics and operations research. This book is concerned primarily with modelling economic and social time series, and with addressing the special problems which the treatment of such series poses. The properties of the models and the methodological techniques used to select them are illustrated with various applications. These range from the modellling of trends and cycles in US macroeconomic time series to to an evaluation of the effects of seat belt legislation in the UK.

Principles Of Optics Electromagnetic Theory Of Propagation Interference And Diffraction Of Light

Abstract: Thank you for reading principles of optics electromagnetic theory of propagation interference and diffraction of light. As you may know, people have search hundreds times for their favorite novels like this principles of optics electromagnetic theory of propagation interference and diffraction of light, but end up in harmful downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they are facing with some infectious bugs inside their computer.

Linear systems

Abstract: Most of the signal processing that we will study in this course involves local operations on a signal, namely transforming the signal by applying linear combinations of values in the neighborhood of each sample point. You are familiar with such operations from Calculus, namely, taking derivatives and you are also familiar with this from optics namely blurring a signal. We will be looking at sampled signals only. Let's start with a few basic examples. Local difference Suppose we have a 1D image and we take the local difference of intensities, DI(x) = 1 2 (I(x + 1) − I(x − 1)) which give a discrete approximation to a partial derivative. (We compute this for each x in the image.) What is the effect of such a transformation? One key idea is that such a derivative would be useful for marking positions where the intensity changes. Such a change is called an edge. It is important to detect edges in images because they often mark locations at which object properties change. These can include changes in illumination along a surface due to a shadow boundary, or a material (pigment) change, or a change in depth as when one object ends and another begins. The computational problem of finding intensity edges in images is called edge detection. We could look for positions at which DI(x) has a large negative or positive value. Large positive values indicate an edge that goes from low to high intensity, and large negative values indicate an edge that goes from high to low intensity. Example Suppose the image consists of a single (slightly sloped) edge:

Heat and Mass Transfer

Abstract: Thermophysical Properties Research Literature Retrieval Guide Edited by Y. S. Touloukian, J. K. Gerritsen and N. Y. Moore Second edition, revised and expanded. Book 1: Pp. xxi + 819. Book 2: Pp.621. Book 3: Pp. ix + 1315. (New York: Plenum Press, 1967.) n.p.