International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Transducers whose outputs are characterized as a charge require signal conditioning to convert the charge produced to a voltage or current for use in instrumentation systems. Blast gauges, in particular, require processing which preserves the transient nature of the data and very fast risetimes, which would otherwise be degraded by long cable runs and parasitic capacitances. A charge amplifier which amplifies and converts a charge to a low-impedance voltage suitable for driving coaxial lines is described, along with theory of operation. Charge amplifiers of the type described are relatively unaffected by temperature and power supply variations, and occupy less than two square inches of printed circuit board space per channel.

Currently in the marketplace, one of the important goals is to improve quality, and reliability. There is great interest in the engineering community to develop a field calibration technique concerning piezoelectric pressure sensor to reduce cost and improve reliability. This paper summarizes the algorithm used to characterize and develop a model for a piezoelectric pressure transducer. The basic concept of the method is to excite the sensor using an electric force to capture the signature characteristic of the pressure transducer. This document presents the frequency curve fitted model based on the high frequency excitation of the piezoelectric pressure transducer. It also presents the time domain model of the sensor. The time domain response of the frequency curve fitted model obtained in parallel with the frequency response of the time domain model and the comparison results are discussed. Moreover, the relation between model parameters and sensitivity extensively is investigated. In order to detect damage and monitor the condition of the sensor on line the resonance frequency comparison method is presented. The relationship between sensitivity and the resonance frequency characteristic of the sensor extensively is investigated. The method of resonance monitoring greatly reduces the cost of hardware. This work concludes with a software implementation of the signature comparison of the sensor based on a study of the experimental data. The software would be implemented in the control system. / Master of Science

This thesis consists of two subjects of research: eliminating, by avoidance or removal, the effects of different types of interference on small signal recording, and a body-sensor transmitter application utilizing piezo sensors. The first topic demonstrates ECG signal and noise signal recording in the presence of various types of interference. A low-pass filter is proposed to remove power-line interference of ECG signals, and a switch between high-pass filters before amplification is proposed to avoid motion artifacts in the ECG signal. Finally, a low-cost noise recording system for educational uses that can record and analyze the noise of resistors and amplifiers in the LabVIEW program is proposed. The second topic concerns the application of a body-sensor transmitter. The sensor uses piezo film and combines the characteristics of piezo film with the characteristics of the human body and can exchange information by capacitor coupling. The signal used in the body-sensor transmitter is designed for a fixed frequency using narrow band-pass filters and is received by receivers via four methods as confirmation. Finally, the charge amplifier designed to detect signals is fabricated using a 0.35£gm 2P4M CMOS process.

Charge detection is essential for a large number of commercial and scientific applications. A charge amplifier is one of the most fundamental building blocks for a detector system. This thesis describes the design, circuit implementation, and post-silicon testing of two different charge amplifier designs, analog and digital, that address some commonly seen fundamental challenges in the charge detection application. In particular, the proposed designs can be integrated with an image charge detector (ICD) to study the characteristics of dust on Mars. The proposed charge amplifier design utilizes a small 10 fF feedback capacitor to achieve a high gain. The fully integrated custom differential charge amplifier design improves the accuracy and robustness of its charge gain, and provides a compact method to extract detector capacitance for gain calibration. Conventional charge amplifiers' charge-to-voltage gain is a function of the detector parasitic capacitance. Therefore, a high precision photo-current calibration method is proposed here to enable an accurate gain calibration. In addition, a novel "digital amplifier" with close to rail-to-rail output swing is proposed to realize an infinite equivalent open-loop gain. Consisting of an ADC and charge pump as the amplifier core, this proposed design maintains a consistent closed-loop gain independent of the input parasitic capacitance. The ADC is realized as a single comparator, i.e. a 1-bit ADC, which, together with an SR latch and a differential charge pump, replaces the conventional analog amplifier core.

The safety concern of aging aircraft is a rising issue in terms of both safety and cost. An aircraft structure failure during flight is unacceptable. A method needs to be developed and standardized to test the integrity of both commercial and military aircrafts. The current method to test the structure of an aircraft requires the aircraft to be taken out of service for inspection; this is costly due to the inspection required to be performed and the lost use from downtime. A novice idea of an on-site structural health monitoring (SHM) system has been proposed to test the integrity of aircraft structure. An on-site system is a system that can be used to perform inspection on an aircraft simultaneously while the aircraft is in use. This SHM system uses the principles of active lamb wave and passive acoustic emission through the use of piezoelectric sensors as the sensing elements. Piezoelectric sensors can be used both as an input device and as a sensing element. This research focuses on the development of the major data acquisition electronic components of the system. These components are charge amplifier, high pass filter, low pass filter and line driver. A charge amplifier converts a high impedance signal to a low impedance signal. A high pass filter attenuates the low frequency content of a signal, while a low pass filter attenuates the high frequency content of a signal. A line driver converts a low current signal to a high current signal. All of these components need to operate up to a frequency of 2 MHz. Off-the-shelf electronics will be used for prototyping as custom components will not be feasible at this point of the research. / Master of Science

L’équipe Physique des Galaxies du Laboratoire d’Astrophysique de Marseille a développé un nouveau type d'interféromètre de Fabry-Perot, équipé de trois actionneurs piézoélectriques amplifiés et de trois capteurs capacitifs permettant le contrôle de l'espacement et du parallélisme des lames de verres de l'ordre de 200 µm avec une précision de positionnement du nm.L'objectif visé de ce manuscrit, composé de 3 parties, est le pilotage de cet interféromètre. La première partie, composée des chapitres 1 et 2, présente les généralités sur l'interférométrie de Fabry-Perot puis décrit les instruments 3DNTT et BTFI où seront installés l'interféromètre de nouvelle génération et son contrôleur associé. La conception et la réalisation d'un amplificateur hybride en vue de la réduction des non-linéarités des actionneurs piézoélectriques mettent fin à cette partie.La deuxième partie, chapitres 3 et 4, décrit le développement et la réalisation du contrôleur. Pour cela, une démarche basée sur le concept du Co-design a été adoptée.Le contrôleur ainsi réalisé est composé d'une carte de développement Microzed dont le cœur est un système sur puce de la série Zynq 7000 EPP et d'une carte d'interfaçage comportant des convertisseurs 3 ADC et 3 DAC et des circuits d'alimentation. La troisième et dernière partie, chapitres 5 et 6, traite de la modélisation d'état de l’interféromètre de Fabry-Perot et de son contrôle : un contrôle classique basé sur la régulation PID et un contrôle robuste et optimal basé sur le filtrage de KALMAN. Cette dernière partie conclut sur les perspectives pouvant découler des contributions de ce travail sur le contrôle et la commande Fabry-Perot. / The Physics of Galaxies Team of Laboratoire d'Astrophysique de Marseille (LAM) has developed a new type of Fabry-Perot, with three amplified piezoelectric actuators and three capacitive sensors to control the spacing and parallelism of mirror plates of approximately 200 µm with a positioning accuracy of 3 nm.The purpose of this manuscript, consisting of 3 parts is the control of this interferometer.The first part, consisting of Chapters 1 and 2 presents the general interferometry Fabry-Perot and then describes 3DNTT and BTFI instruments which will be installed the next generation interferometer and its associated controller. The design and implementation of a hybrid amplifier to reduce non-linearities of the piezoelectric actuators (hysteresis and creep) end this first part.The second part, Chapters 3 and 4, describes the development and implementation of the controller.For this, an approach based on codesign concept was adopted. The thus achieved controller consists of a Microzed development board whose heart is a system on chip of the 7000 series Zynq EPP (FPGA + Dual-Core ARM Cortex A9) and an interface card with converters (3 ADC and 3 DAC) and power supply circuits.For the finalization of the controller, two steps are necessary: hardware design in Xilinx Vivado and software design in Xilinx SDK.The third and final section, chapters 5 and 6 deals with the Fabry-Perot space-state modeling and its control: a classic control based on PID control and a robust and optimal control based on KALMAN filtering. This last part concludes the outlook may result from contributions of this work on the monitoring and control of the Fabry-Perot.

Målet med detta arbete var att konstruera en mycket känslig laddningsförstärkare som kan detektera och förstärka laddningar i storleksordningen femtocoulomb. Laddningsförstärkaren är tänkt att användas vid Habia Cables kabeltillverkning för att karaktärisera lågbruskabel med avseende på störning genererad av triboelektrisk uppladdning. Den bästa lågbruskabel Habia Cable tillverkar, så kallad super-lågbruskabel, uppvisar så låg triboelektrisk störning att vanliga laddningsförstärkare inte kan detektera den, därav behovet av en känsligare laddningsförstärkare. I en inledande litteraturstudie söktes information om triboelektrisk uppladdning och hur triboelektrisk uppladdning orsakar störning i kablar. Genom litteraturstudien inhämtades också teori kring hur laddningsförstärkare är uppbyggda och vilka speciella krav som ställs på dessa för att kunna detektera mycket små laddningar. Sedan vidtog arbete med att konstruera en laddningsförstärkare med kretsdesign, kretskortsdesign, lödning, inbyggnad och testning. Resultatet blev en laddningsförstärkaren som kan mäta laddningar från uppskattningsvis 0,1 femtocoulomb till 100 picocoulomb. Vid kvantifiering av triboelektrisk störning i super-lågbruskabel uppmättes så låga laddningar som 1,3 femtocoulomb. / The goal of this project was to construct a sensitive charge amplifier that could detect and amplify femtocoulomb charges. The charge amplifier is to be used at Habia Cable manufacturing sites to quantify the triboelectric noise performance of lownoise cables. Super-low-noise cables manufactured by Habia Cable perform so well regarding triboelectric noise that common charge amplifiers cannot detect the noise, thus the need for a more sensitive charge amplifier. Initially a literature study was performed in order to better understand triboelectric charging and triboelectric noise in cables. Thru the literature study knowledge of charge amplifiers and low charge measurements was also gained. After the literature study a charge amplifier was constructed. Work included circuit design, PCB design, soldering, construction of enclosure and testing. Tests shows that the constructed charge amplifier can detect charges as low as 1.3 femtocoulomb when quantifying triboelectric noise in super-low-noise cables. The charge amplifier can measure charges from approximately 0.1 femtocoulomb to 100 picocoulomb.

<p>Disertacija istražuje primenu fleksibilne elektronike za<br />kapacitivne senzore ugla i ugaone brzine tipa apsolutnog i<br />inkrementalnog enkodera cilindrične strukture. Razmatraju se dve<br />strukture, apsolutnog i inkrementalnog enkodera. Izvršena je analiza<br />uticaja mehaničkih nesavršenosti na funkciju kapacitivnosti.<br />Razvijena su dva prototipa kapacitivnih senzora za statičko i<br />dinamičko ispitivanje karakteristika senzora. Razvijena je<br />elektronika za obradu senzora inkrementalnog tipa sa<br />autokalibracijom senzora.</p> / <p>In this thesis a research on application of flexible electronics for capacitive<br />angular position and speed sensors, referred to as absolute and incremental<br />encoders, is done. It considers two structures of absolute and incremental<br />encoder type. An analysis of mechanical inaccuracies influence on a<br />capacitance function is conducted. Two prototypes are developed and used<br />for static and dynamic measurements of capacitive sensor&#39;s characteristics.<br />An electronics front-end for a capacitive two channel incremental encoder with<br />auto-calibration is developed.</p>

CdZnTe-Detektoren, zur direkten Messung von Gammastrahlung, die bei der Behandlung mit beschleunigten Teilchen entsteht, besitzen das Potential eine Reichweitenkontrolle zu ermöglichen und die Strahlendosis zu erfassen. Jedoch stellt die Identifizierung einzelner, energetisch nahe beieinander liegenden Photonenenergien, bei einem solchen Volumendetektor eine besondere Herausforderung dar. Die vorliegende Arbeit beschäftigt sich mit der Entwicklung von Methoden zur Korrektur der Signalformen am Volumenhalbleiter CdZnTe und der damit verbundenen Verbesserung der Energie- und Zeitinformation des Detektors. Dies ist wichtig für den Einsatz in der therapeutischen Medizin mit beschleunigten Teilchen, da Ladungsträger durch Gammastrahlung in unterschiedlichen Tiefen des Detektors generiert werden und einen tiefenabhängigen Fehler in der Detektorgenauigkeit erzeugen. / CdZnTe detectors, used for the direct measurement of gamma radiation generated during the treatment with accelerated particles, have the potential to provide a range control and to detect the radiation dose. However, the identification of individual energetically close photon energies in such a volume detector is a particular challenge. The present work deals with the development of methods for correcting the signal forms of the CdZnTe and the associated improvement of the energy and time information of the detector This is important for use in accelerated particle medicine because charge carriers are generated by gamma radiation at different depths of the detector and produce a depth dependent error in detector accuracy.