DATA ACQUISITION AND SIGNAL PROCESSING FOR SMART SENSORS This Page Intentionally Left Blank DATA ACQUISITION AND SIGNAL PROCESSING FOR SMART SENSORS Nikolay V. Kirianaki and Sergey Y. Yurish International Frequency Sensor Association, Lviv, Ukraine Nestor 0. Shpak Institute of Computer Technologies, Lviv, Ukraine Vadim P. Deynega State University Lviv Polytechnic, Ukraine JOHN WILEY & SONS, LTD Capyight O 2002 by John Wiley & Sons. Ltd Baffins Lane. Chichester, West Sussex, PO19 IUD. England Intemtrional (+44) 1243 779777 e-mail (fur d m a nd cunomcr sewicc cnquirics): [email protected] Visit our Home Page on http:/lwuw.wileyeum~.cont All Rights Resewed. No part of Lhir publication may be repmduced stored in a retrieval systm, or transmined, in any form or by any means, electmnic. mechanical, photocopying. wording. Sca~inga r otherwise, except under the terms of the Copyri~ht.D rcigns and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd. 90 Tottenham Court Road, Lmdon. UK WIP OLP, without the permission in writing of the Puhlishcr. Neither the authors nor Jon Wtley & Sons Ltd accept any responsibility or liability for loss or damage occasioned to any person or property thmugh using Ihe materi& instructians, mcthod~o r iPdueabslis choenr teuxn.oe nds hsel,vr e dinis, colar iamc tainllg i moro rleiefrda winainrrga nfmtiems. aincctilnugd ian--e am reesrcuhlta onfta sbuiclithv uosfe .l itTnheess a fuothr oarnsv a nd particular purpose. Designations used hy companies to distinguish their products an. o ften claimed a.s .t rademarks. In all instances where John Wile~v &,S ans is awnre of a claim~~. th. e omduet names aooear in initial capilal or capital letters. Readers, h~o~w ever, shou~ ld~ contact the appropriate companies for more complete informnt~rm= garding mademarks and registration. Other Wiley Ediroriul OQices John Wtley & Sons, Inc., Q€ 5 Third Avenue, New York. NY 10158-W12. USA Wiley-VCH Vexlag GmbH, Pappelallce 3, D-69469 Weinheim. Germany John Wiley & Sons Australia. L14 33 Park Road, Milton, Queensland 4064. Australia John Wiley & Sons (Asia) Pte Ltd. 2 Clemnti Laop W41. Jin Xing Disuipark. Singapore 129809 John W~ley& Sons (Canada) Ltd. 22 Worcestef Road Rexdale. Ontario M9W ILI. Canada Librnrg of Congress CaIaloging-in-Publirolion Data .. . Data acquisition and signal processing for sman senson / Nikolay V. Kirianaki let al.1. p. cm. Includes bibliographical references and index. ISBN 0-470-84317-9 calk. paper) 1. Detcctoa. 2. Miercpmcessors. 3. Signal processing. 4. Automatic data collection systems. I. Kirianaki. Nikolai Vladimirovich. B&k Ubmry Cataloguing in Publimlion hta A catalogue record for this book is available fmm the British Library ISBN 0 470 84317 9 'WF.,vrnn.e..ts.de. r ainn~ d.l .O h. o/1~u2n.adr .il~n i Gm-rse.a h-t ,vR Lriatas-einn hva-y~ rd~ Rsi dRdilveas~t ~e tLdim~. iu~teadl ~Cfhn e&rMd aK i.i nIgn'dsi aL ynn This hook is printed on acid-free paper responsibly rnanufxlured from sustainable fomtry. in which at l&t two trees are planted for each one used fur paper production. CONTENTS Preface List of Abbreviations and Symbols xiii Intmduction 1 Smart Sensors for Electrical and Non-Electrical, Physical and Chemical Variables: Tendencies and Perspectives 1. I Temperature IC and Smart Sensors 1.2 Pressure IC and Smart Sensors and Accelerometers 1.3 Rotation Speed Sensors 1.4 Intelligent Opto Sensors 1.5 Humidity Frequency Output Sensors 1.6 Chemical and Gas Smart Sensors Summary 2 Converters for Different Variables to Frequency-Time Parameters of the Electric Signal 2.1 Voltage-to-Frequency Converters (VFCs) 2.2 Capacitance-to-Period (or Duty-Cycle) Converters Summary 3 Data Acquisition Methods for Multichannel Sensor Systems 3.1 Data Acquisition Method with Time-Division Channelling 3.2 Data Acquisition Method with Space-Division Channelling 3.3 Smart Sensor Architectures and Data Acquisition 3.4 Main Errors of Multichannel Data-Acquisition Systems 3.5 Data Transmission and Error Protection 3.5.1 Essence of quasi-ternary coding 3.5.2 Coding algorithm and examples 3.5.3 Quasi-ternary code deccding Summary vi CONTENTS 4 Methods of Frequency-to-Code Conversion 4.1 Standard Direct Counting Method (Frequency Measurement) 4.2 Indirect Counting Method (Period Measurement) 4.3 Combined Counting Method 4.4 Method for Frequency-to-Code Conversion Based on Discrete Fourier Transformation 4.5 Methods for Phase-Shift-to-Code Conversion Summary 5 Advanced and Self-Adapting Methods of Frequency-to-Code Conversion 5.1 Ratiometric Counting Method 5.2 Reciprocal Counting Method 5.3 Mfr Counting Method 5.4 Constant Elapsed Time (CET)M ethod 5.5 Single- and Double-Buffered Methods 5.6 DMA Transfer Method 5.7 Method of Dependent Count 5.7.1 Method of conversion for absolute values 5.7.2 Methods of conversion for relative values 5.7.3 Methods of conversion for frequency deviation 5.7.4 Universal method of dependent count 5.7.5 Example of realization 5.7.6 Metrological characteristics and capabilities 5.7.7 Absolute quantization emr A, 5.7.8 Relative quantization error 8, 5.7.9 Dynamic range 5.7.10 Accuracy of frequency-to-rode wnverIers based on MDC 5.7.1 1 Calculation emr 5.7.12 Quantization error (error of method) 5.7.13 Reference frequency e m 5.7.14 Trigger ermr 5.7.15 Simulation results 5.7.16 Examples 5.8 Method with Non-Redundant Reference Frequency 5.9 Comparison of Methods 5.10 Advanced Method for Phase-Shift-to-Code Conversion Summary 6 Signal Pmcessing in Quasi-Digital Smart Sensors 6.1 Main Operations in Signal Processing 6.1.1 Adding and subtraction 6.1.2 Multiplication and division 6.1.3 Frequency signal unification 6.1.4 Derivation and integration CONTENTS 6.2 Weight Functions, Reducing Quantization Error Summary 7 Digital Output Smart Sensors with Software-Controlled Performances and Functional Capabilities 7.1 Program-Oriented Conversion Methods Based on Ratiometric Counting Technique 7.2 Design Methodology for Program-Oriented Conversion Methods 7.2.1 Example 7.3 Adaptive FTM with Increased Speed 7.4 Error Analysis of PCM 7.4.1 Reference m r 7.4.2 Calculation error 7.4.3 E mo f Tm forming 7.5 Correction of PCM's Systematic Errors 7.6 Modified Method of Algorithm Merging for PCMs Summary 8 Multichannel Intelligent and Virtual Sensor Systems 8.1 One-Channel Sensor Interfacing 8.2 Multichannel Sensor Interfacing 8.2.1 Smart rotation speed sensor 8.2.2 Encoder 8.2.3 Self-adaptive method f am tation speed measurements 8.2.4 Sensor interfacing 8.3 Multichannel Adaptive Sensor System with Space-Division Channelling 8.4 Multichannel Sensor Systems with Time-Division Channelling 8.5 Multiparameters Sensors 8.6 Virtual Instrumentation for Smart Sensors 8.6.1 Set of the basic models for measuring insmments 8.7 Estimation of Uncertainty for Virtual Instruments Summary 9 Smart Sensor Design at Software Level 9.1 Microcontroller Core for Smart Sensors 9.2 Low-Power Design Technique for Embedded Microcontrollers 9.2.1 lnsrmction selection and ordering 9.2.2 Code size and speed optimizations 9.2.3 Jump and call optimizations 9.2.4 Cycle optimization 9.2.5 Minimizing memory access cost 9.2.6 Exploiting low-power features of the hnrdware 9.2.7 Compiler optimization for low power Summary viii CONTENTS 10 Smart Sensor Buses and Interface Circuits 10.1 Sensor Buses and Network Protocols 10.2 Sensor Interface Circuits 10.2.1 Universal transducer interface (Un) 10.2.2 Time-todigital convener (TDC) Summary Future Directions References Appendix A What is on the Sensors Web Portal? Glossary Index PREFACE Smart sensors are of great interest in many fields of industry, control systems, biomed- ical applications, etc. Most books about sensor instrumentation focus on the classical approach to data acquisition, that is the information is in the amplitude of a voltage or a current signal. Only a few book chapters, articles and papers consider data acquisition from digital and quasi-digital sensors. Smart sensors and microsensors increasingly rely on resonant phenomena and variable oscillators, where the information is embedded not in the amplitude but in the frequency or time parameter of the output signal. As a mle, the majority of scientific publications dedicated to smart sensors reflect only the tech- nological achievements of microelectronics. However, modem advanced microsensor technologies require novel advanced measuring techniques. Because data acquisition and signal processing for smart sensors have not been adequately covered in the literature before, this book aims to fdl a significant gap. This book is based on 40 years of the authors' practical experience in the design and creation of sensor instrumentation as well as the development of novel methods and algorithms for frequency-timedomain measurement, conversion and signal processing. Digital and quasi-digital (frequency, period, duty-cycle. time interval and pulse number output) sensors are covered in this book. Research results, described in this book, are relevant to the authors' international research in the frame of different R&D projects and International Frequency Sensor Association (IFSA) activity. Who Should Read this Book? This book is aimed at PhD students, engineers, scientists and researchers in both academia and industry. It is especially suited for professionals working in the field of measuring instruments and sensor instrumentation as well as anyone facing new challenges in measuring. and those involved in the design and creation of new digital smart physical or chemical sensors and sensor systems. It should also be useful for students wishing to gain an insight into this rapidly expanding area. Our goal is to provide the reader with enough background to understand the novel concepts, principles and systems associated with data acquisition, signal processing and measurement so that they can decide how to optimize their sensor systems in order to achieve the best technical performances at low cost.
Description: