Sensors and actuators (1)

Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C000 Final Proof page i 19.12.2006 1:34pm SENSORS AND ACTUATORS Control Systems Instrumentation Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C000 Final Proof page ii 19.12.2006 1:34pm Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C000 Final Proof page iii SENSORS AND ACTUATORS Control Systems Instrumentation CLARENCE W de SILVA Boca Raton London New York CRC Press is an imprint of the Taylor & Francis Group, an informa business 19.12.2006 1:34pm Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C000 Final Proof page iv 19.12.2006 1:34pm CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2007 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, an Informa business No claim to original U.S Government works Printed in the United States of America on acid-free paper 10 International Standard Book Number-10: 1-4200-4483-4 (Hardcover) International Standard Book Number-13: 978-1-4200-4483-6 (Hardcover) This book contains information obtained from authentic and highly regarded sources Reprinted material is quoted with permission, and sources are indicated A wide variety of references are listed Reasonable efforts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use No part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers For permission to photocopy or use material electronically from this work, please access www.copyright.com (http:// www.copyright.com/) or contact the Copyright Clearance Center, Inc (CCC) 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400 CCC is a not-for-profit organization that provides licenses and registration for a variety of users For organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe Library of Congress Cataloging-in-Publication Data De Silva, Clarence W Sensors and actuators : control system instrumentation / Clarence W de Silva p cm “A CRC title.” Includes bibliographical references and index ISBN-13: 978-1-4200-4483-6 (alk paper) ISBN-10: 1-4200-4483-4 (alk paper) Automatic control Detectors Actuators I Title TJ213.D386 2007 670.42’7 dc22 Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the CRC Press Web site at http://www.crcpress.com 2006024039 Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C000 Final Proof page v 19.12.2006 1:34pm Dedication Dedicated to Charmaine, CJ, and Cheryl, since their ‘‘senses’’ have developed and since they have become rather ‘‘active.’’ But as artificers not work with perfect accuracy, it comes to pass that mechanics is so distinguished from geometry that what is perfectly accurate is called geometrical; what is less so, is called mechanical However, the errors are not in the art, but in the artificers Sir Isaac Newton, Principia Mathematica, Cambridge University, May 8, 1686 Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C000 Final Proof page vi 19.12.2006 1:34pm Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C000 Final Proof page vii 19.12.2006 1:34pm Preface This is an introductory book on the subject of control system instrumentation, with an emphasis on sensors, transducers, and actuators Specifically, the book deals with ‘‘instrumenting’’ a control system through the incorporation of suitable sensors, actuators, and associated interface hardware It will serve as both a textbook for engineering students and a reference book for practicing professionals As a textbook, it is suitable for courses in control system instrumentation; control sensors and actuators; and mechatronics; or a second course in feedback control systems The book has adequate material for two 14-week courses, one at the junior (third-year undergraduate) or senior (fourth-year undergraduate) level and the other at the first-year graduate level In view of the practical considerations, design issues, and industrial techniques that are presented throughout the book, and in view of the simplified and snap-shot style presentation of more advanced theory and concepts, the book will serve as a useful reference tool for engineers, technicians, project managers, and other practicing professionals in industry and in research laboratories, in the fields of control engineering, mechanical engineering, electrical and computer engineering, manufacturing engineering, aerospace engineering and mechatronics A control system is a dynamic system that contains a controller as an integral part The purpose of the controller is to generate control signals, which will drive the process to be controlled (the plant) in the desired manner Actuators are needed to perform control actions as well as to directly drive or operate the plant Sensors and transducers are necessary to measure output signals (process responses) for feedback control; to measure input signals for feedforward control; to measure process variables for system monitoring, diagnosis and supervisory control; and for a variety of other purposes Since many different types and levels of signals are present in a control system, signal modification (including signal conditioning and signal conversion) is indeed a crucial function associated with any control system In particular, signal modification is an important consideration in component interfacing It is clear that a course in control system instrumentation should deal with sensors and transducers, actuators, signal modification, and component interconnection Specifically, the course should address the identification of control system components with respect to functions, operation and interaction, and proper selection and interfacing of these components for various control applications Parameter selection (including system tuning) is an important step as well Design is a necessary and integral part of control system instrumentation, for it is design that enables us to build a control system that meets the performance requirements—starting, perhaps, with basic components such as sensors, actuators, controllers, compensators, and signal modification devices The book addresses all these issues, starting from the basics and systematically leading to advanced concepts and applications The approach taken in the book is to treat the basic types of control sensors and actuators in separate chapters, but without losing sight of the fact that various components in a control system have to function as an interdependent and interconnected (integrated) group in accomplishing the specific control objectives Operating principles, modeling, design considerations, ratings, performance specifications, and applications of the individual components are discussed Component integration and design considerations are addressed as well To maintain clarity and focus and to maximize the usefulness of the book, the material is presented in a manner that will be useful to anyone with a basic engineering background, be it electrical, mechanical, mechatronic, aerospace, control, manufacturing, chemical, civil, or computer Case studies, worked examples, and exercises are provided throughout the book, drawing from such application systems as Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C000 Final Proof page viii 19.12.2006 1:34pm robotic manipulators, industrial machinery, ground transit vehicles, aircraft, thermal and fluid process plants, and digital computer components It is impossible to discuss every available control system component in a book of this nature; for example, thick volumes have been written on measurement devices alone In this book, some types of sensors and actuators are studied in great detail, while some others are treated superficially Once students are exposed to an in-depth study of some components, it should be relatively easy for them to extend the same concepts and the same study approach to other components that are functionally or physically similar Augmenting their traditional role, the problems at the end of each chapter serve as a valuable source of information not found in the main text In fact, the student is strongly advised to read all the problems carefully in addition to the main text Complete solutions to the end-of-chapter problems are provided in a solutions manual, which is available to instructors who adopt the book About 10 years after my book Control Sensors and Actuators (Prentice-Hall, 1989) was published, I received many requests for a revised and updated version of the book The revision was undertaken in the year 2000 during a sabbatical leave As a result of my simultaneous involvement in the development of undergraduate and graduate curricula in mechatronics and in view of substantial new and enhanced material that I was able to gather, the project quickly grew into one in mechatronics and led to the publication of the monumental 1300-page textbook: Mechatronics—An Integrated Approach (Taylor & Francis, CRC Press, 2005) In meeting the original goal, however, the present book was subsequently developed as a condensed version of the book on mechatronics, while focusing on control sensors and actuators The manuscript for the original book evolved from the notes developed by me for an undergraduate course entitled ‘‘Instrumentation and Design of Control Systems’’ and for a graduate course entitled ‘‘Control System Instrumentation’’ at Carnegie Mellon University The undergraduate course was a popular senior elective taken by approximately half of the senior mechanical engineering class The graduate course was offered for students in electrical and computer engineering, mechanical engineering, and chemical engineering The prerequisites for both courses were a conventional introductory course in feedback controls and the consent of the instructor During the development of the material for that book, a deliberate attempt was made to cover a major part of the syllabuses for the two courses: ‘‘Analog and Digital Control System Synthesis,’’ and ‘‘Computer Controlled Experimentation,’’ offered in the Department of Mechanical Engineering at the Massachusetts Institute of Technology At the University of British Columbia, the original material was further developed, revised, and enhanced for teaching courses in mechatronics and control sensors and actuators The material in the book has acquired an application orientation through my industrial experience in the subject at places such as IBM Corporation, Westinghouse Electric Corporation, Bruel and Kjaer, and NASA’s Lewis and Langley Research Centers The material presented in the book will serve as a firm foundation, for subsequent building up of expertise in the subject—perhaps in an industrial setting or in an academic research laboratory—with further knowledge of control hardware and analytical skills (along with the essential hands-on experience) gained during the process Undoubtedly, for best results, a course in control sensors and actuators, mechatronics, or control system instrumentation should be accompanied by a laboratory component and class projects Main Features of the Book The following are the main features of the book, which will distinguish it from other available books on the subject: Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C000 Final Proof page ix 19.12.2006 1:34pm The material is presented in a progressive manner, first giving introductory material and then systematically leading to more advanced concepts and applications, in each chapter The material is presented in an integrated and unified manner so that users with a variety of engineering backgrounds (mechanical, electrical, computer, control, aerospace, manufacturing, chemical, and material) will be able to follow and equally benefit from it Practical procedures and applications are introduced in the beginning and then uniformly integrated throughout the book Key issues presented in the book are summarized in boxes and in point form, at various places in each chapter, for easy reference, recollection, and for use in Power-Point presentations Many worked examples and case studies are included throughout the book Numerous problems and exercises, most of which are based on practical situations and applications, are given at the end of each chapter References and reading suggestions are given at the end of the book, for further information and study A solutions manual is available for the convenience of the instructors Clarence W de Silva Vancouver, Canada Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C011 Final Proof 660 Sensors and Actuators: Control Systems Instrumentation End-effector design, 317 Epicyclic, 633 Equal-pitch stepper, 412 multiple-stack, 423 Equation inversion, 112 Equivalent gage factor, 285 Error absolute, 182 deterministic, 148, 180 encoder, 381 measurement, 180 random, 180 square root of sum of squares, 182 SRSS, 182 stochastic, 180 systematic, 148, 180 Error analysis, 179 Error combination, 181, 183 Error sources, DAC, 85 Etching, encoder, 360 Excitation frequency control, 554, 568, 597 Experimental modeling, 207 dc motor, 508 Extrinsic method, ultrasound, 326 F Fan-in, fluidic, 604, 622 Fan-out capability, fluidic, 604 Faraday’s law, 239 Fast response, 146 Fasteners, 625 Fault detection, 76 Fault diagnosis, 76 Fault monitoring, 141 Feedback control, 207 ac motor, 561 dc motor, 512, 523 force, 266 hydraulic, 591, 593 stepper model-based, 455 stepper, 452 Feedback control system, Feedback transfer function, 153 Feedforward control, 6, 10, 207 Feedforward force control, 266 Ferrite magnets, 494 Ferromagnetic core, 223 FET, 40 FFT analyzer, 128 Fiber-optic gyroscopes, 323 position sensors, 321 tactile sensors, 313 tactile sensor, extrinsic, 311, 320 tactile sensor, intrinsic, 311, 320 page 660 9.12.2006 9:00pm Field circuit, dc motor, 498 Field control, 512, 522, 524 Field feedback control, ac motor, 561 Field voltage, 509, 512, 522, 549 Fieldbus, 15 Field-strength=mass ratio, 494 Filter cutoff frequency, 63 Filter order, 56 Filter roll-off rate, 58 Filters active, 55 passive, 55 poles, 56 tracking, 55 analog, 52 band-pass, 53, 63 band-reject, 53, 67 high-pass, 53, 61 low-pass, 53, 56 notch, 53, 67 Filter stages, 56 Firing circuit, see Thyristor Fish cutting system automated, 480 hydraulic control, 621 Flapper valves, 599, 601 Flexible coupling, 626, 633, 644 Flexispline, 632, 634, 636, 644 Flight simulators, 24 Floats flow sensor, 330 Flow control valves, 618 solenoid-actuated, 620 Flow gain, 580 Flow meters angular-momentum, 330 Coriolis, 330 hot-film anemometer, 330 hot-wire anemometer, 330 laser-Doppler velocimeter, 330 liquid level, 330 magnetic induction, 330 turbine, 330 ultrasonic, 330 Flow sensors, 329 nozzle, 330 orifice plate, 330 pitot tube, 330 Venturi meter, 330 Flow–pressure coefficient, 580 Fluid power system, 573 Fluidics, 602 amplifiers, 605 applications, 607 AND gate, 604 control systems, 606 Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C011 Final Proof page 661 9.12.2006 9:00pm Index interfacing, 606 logic circuits, 603 motion sensors, 604 pulse generator, 622 Flux density, 239, 489 Flux linkage, 220 Flux vector drive, 561 FM, 69 Foil-type strain gages, 275 Fold catastrophe, 157 Force capacity, tactile sensors, 309 Force control feedback, 266 feedforward, 266 Force control problems, 266 Force dexterity, 315, 351 Force resolution, tactile sensors, 309 Force sensitivity, tactile sensors, 309 Force sensors, 307 location, 273 Force-motion causality, 261 Forward transfer function, 153 Foundation Fieldbus, 15 Fourier analysis bandwidth, 163 Four-phase eight-pole stepper, 417 Four-way spool valves, 579 Four-way valve, bridge circuit, 597 Fractional slip, induction, 549 Frequency analyzers, 128 Frequency control, 554, 568, 597, 613 Frequency creation, 157 Frequency-domain performance specification, 152 Frequency modulation, 69 Frequency resolution, 164 Frequency response function, 29, 151 Frequency response, piezoelectric accelerometers, 256 Frequency transfer function, 29, 151 Frequency-to-voltage converters, 119, 123 Frequency uncertainty, 163 FRF, 151 Friction drives, 627, 634, 646 Frictional torque, 297, 305, 344 Fringes, 323 Front-end auxiliary element, sensor, 210, 218 Front-end element, accelerometer, 255 FTF, 151 Full scale drift, 159 Full-load speed, 504 Full-scale value, DAC, 82 Full-stepping sequence, motor, 410, 414 Furnace, 10, 12 FVC, 119, 123 661 G Gage factor, 274, 279 equivalent, 285 Gain, 155 tachometer, 241 Gain margin, 153 Gain-bandwidth product, amplifier, 48 Gas-charged accumulators, 598 GBP, 48 Gear backlash, 77 Gear optimization, 35 Gear pump, 574 Gear ratio, encoder, 375 Gear transmission, 644 Gear, motor, 542 Gimbal axis, 319 Glitches, DAC, 86 Graphite contacts, 493 Grating lines, 391 Gratings, index, 391 Gratings, master, 391 Gray coding, 377 Ground transit vehicle, 342 Ground-loop noise, 51 Gyroscopes fiber-optic, 323 ring, 323 Gyroscopic sensors, 318 Gyroscopic torque, 319 H Half-bridge circuits, 105 Half-power bandwidth, 163 Half stepping sequence, motor, 407, 414 Half-wave demodulation, 77 Hall-effect sensors, 388, 495, 612 Hall-effect shaft encoder, 389 Hard-disk drive, 25, 253, 343, 350 Hardening devices, 157 Hardware digital filters, 100 Hardware features, encoder, 365 Hardware linearization, 113 bridge, 105 Harmonic drive, 353, 497, 616, 632 Harmonics, 158 HDD, 25, 253, 343, 350 Helical tubes, 328 He–Ne lasers, 320, 325 Hierarchical control, 17 Hierarchical sensory architectures, 335 High sensitivity, 146 High-pass filters, 53, 61 High-speed ground transit vehicle, 342 Hold command, 95 Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C011 Final Proof 662 Sensors and Actuators: Control Systems Instrumentation Holding torque, stepper, 406, 412, 426, 433, 447, 456, 459, 462 Home heating, 2, 10, 12 Hot junction, thermocouple, 332 Hot lead, 51 Hot-film anemometers, 330 Hot-wire anemometers, 330 Houdaille damper, stepper, 442 Hybrid electric vehicle, 24 Hybrid stepper motor, 412, 425 Hydraulic accumulators, 597 Hydraulic actuators, 571, 583 pump-controlled, 597 Hydraulic circuits, 601 Hydraulic control system, 572, 585, 593 Hydraulic lead action, 618 Hydraulic motors, 574, 583 Hydraulic power supply, pump regulated, 61 Hydraulic pulse generators, 200 Hydraulic pumps, 574 Hydraulic time constant, 587, 591 Hydraulic valves, 577 Hysteresis, 156 I I=O board, 79 Imbalance output method, 101 Impedance bridge, 107, 244 Impedance characteristics, 28 Impedance control, 269 Impedance matching, 33, 146 mechanical, 34 Impedance transformers, 33 Impedance-matching amplifiers, 33 IMS, 18 Incremental encoders, 359, 363 linear, 402 Independent linearity, 160 Index gratings, 391 Index pulse, 359 Induction motors, 544 control, 553 slip, 549 torque–speed, 550 transfer-function model, 561 Input impedance, 29, 133, 153, 159 op-amp, 40 Instability, 154 Instrument accuracy, 180 Instrument bandwidth, 162, 164 Instrument error analysis, 179 Instrument ratings, 158 Instrumentation amplifier, 44 Instrumentation, control system, page 662 9.12.2006 9:00pm Instrumented pen, 344 Integral control, 148 hydraulic, 592 Integral rate, Integral time constant, Integrated circuit (IC), 38 Integrating ADC, 88 Intelligent mechatronic system, 18 Intelligent sensors, 335 Interceptive, binary transducer, 394 Interconnectability, 153 Interface card, motor, 529 Interfacing, fluidic, 606 Interferometers, laser Doppler, 322, 324 Interferometry, 323 Interpolation, encoder, 371 Interrogation pulse, 327 Intrinsic method, ultrasound, 326 Inverted pendulum, 204 Inverting amplifiers, 44 Inverting input, op-amp, 40 Ionic polarization, 253 J Jerk, 209, 342 Jump phenomenon, 157 K Kiln, wood drying, L Ladder DAC, 83 Lag compensation, 148 Laminar angular speed sensor, 604 Laminated construction, fluidic, 606 Lanchester damper, 474 stepper, 442 Lasers, 320 Laser Doppler interferometers, 324 Laser interferometers, 322 Laser-Doppler velocimeters, 330 Lead hot, 51 neutral, 51 Lead action, hydraulic, 618 Lead screw and nut, 460, 628, 642 Lead zirconate titanate, 253 Leakage inductance, tachometer, 242 Least significant bit, 81 Lectern, automated, 479 LED, 322 Lenz’s law, 489 Level sensors, 354 Light-emitting diode, 322 Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C011 Final Proof page 663 9.12.2006 9:00pm Index Limit cycles, 157 Limit switch, 394 Line frequency, 546 Linear actuators, 569 Linear amplifier, 529, 542 dc motor, 610 Linear encoders, 389, 402 Linear motors, 570 Linear stepping motors, 471 Linearity, 155, 159 static, 146 Linearization hardware, 113 software, 112 Linearizing devices, 110, 158 Linearizing resistors, 339 Linear-variable differential transducers, 222 Linear-variable differential transformers, 222 Liquid level sensor, capacitive, 247 Liquid level, floats, 330 Liquid manometers, 328 Lissajous patterns, 130 Load bearing components, 625 Load cell, 307 strain-gage, 278 Load equation, hydraulic system, 584 Load impedance, tachometer, 242 Loading, 153 encoder, 380 tachometer, 242 Loading effects, 146 Loading error, accelerometer, 258 Loading nonlinearity, potentiometer, 212 Location, strain-gage torque sensor, 298 Loop gain, 148 Loop transfer function, 154 Lorentz’s law, 489 Low-pass filters, 53, 56 LSB, 81 LVDT, 135, 143, 222 M Machining operation, 344 Magnetic field, rotating, 495, 544, 567 Magnetic induction flow meter, 330 Magnetic materials, 494, 497 Magnetic saturation encoder, 360 Magnetic torque, 240, 498 Magnetostrictive displacement sensors, 327 Magnitude at resonance, 153 Magnitude, 155 Manipulator joint, 345 Manufacturing tolerances, encoder, 381 Marginal stability, 154 Mars exploration, 24 663 Masking disk, 365, 399 Master gratings, 391 Material transfer unit, 483 Mean, 190 Mean time between failure, 402 Measurand, 208 Measured value, 180 Measurement accuracy, 180 Measurement error, 180 Measuring device, 208 perfect, 146 Mechanical components, 625 Mechanical damping, stepper, 440 Mechanical impedance matching, 34 Mechanical loading, 135, 493 Mechanical mobility, 29 Mechanical switches, 569 Mechanical tachometers, 165 Mechanical time constant actuators, 515, 521, 523, 538, 587, 591 tachometers, 241 Medical imaging, 326 MEMS accelerometers, 280 MEMS-based sensors, 320 MEMS strain-gage accelerometer, 352 Metal-can package, 38 Microactuators, 253 Microminiature sensors, 335 Microstepping, motor, 421 Microswitches, 394 Milling machine, Miniature stepper motors, 253 Mobility, 29 Model-based feedback control, stepper, 455 Modeling, tachometer, 239 stepper motor, 446 Modular construction, fluidic, 606 Modulated signal, 243 Modulating signal, 69 Modulation theorem, 73 Modulators, 69 Moire´ fringe displacement sensors, 390 Monitoring, 207 fault, 141 Monochromatic light, 320 Monolithic form, 38 Monomode fibers, 322 Monotonicity ADC, 93 DAC, 86 MOSFET, 40, 136 Most significant bit, 81 Motion dexterity, 315, 351 Motion resolution, 192 Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C011 Final Proof 664 page 664 9.12.2006 9:00pm Sensors and Actuators: Control Systems Instrumentation Motion sensors, 209 fluidic, 604 Motors dc, 488 hydraulic, 574, 583 induction, 544 stepper, 405 Motor current torque sensors, 305 Motor data, 537 Motor driver, 528, 529, 537, 540, 542, 544, 553, 561 Motor gear, 542 Motor parameter measurement, 516 Motor selection, dc, 537, 539 Motor sizing, 541 Motor time constants, 515, 521, 523, 591 Mounting methods, accelerometer, 257 MSB, 81 MTBF, 402 Multiple phase energization, stepper damping, 446 Multiple-stack steppers, 412, 422 equal-pitch, 423 unequal-pitch, 424 Multiplexers, 9, 79, 96 Multistage servovalves, 600 Multiterm controllers, 524 Mutual-induction proximity sensors, 232 Mutual-induction transducers, 221 MUX, 96 channel-select rate, 96 N Natural frequency damped, 148 undamped, 148 Network bandwidth, 162 Network interface card, 17 Networked industrial plant, 16 Neutral lead, 51 NIC, 17 No-load speed, 504 stepper, 456 No-load voltage, 29 Noninverting amplifiers, 44 Noninverting input, op-amp, 40 Nonlinear feedback, 158 Nonlinearity error, potentiometer, 212, 219 Nonlinearity limit, strain-gage, 295 Nonlinearity ADC, 93 DAC, 86 dc motor, 494 dynamic, 155 static, 155 strain gage, 285 Notch filters, 53, 67 Nozzle flow sensors, 330 n-type gages, 285 Null position, LVDT, 222 Null voltage, 222 Number of windows, encoder, 375 Nyquist frequency, 56, 80, 128, 170 O Octaves, 152 Offset, 148 Offset current, amplifier, 41, 49, 50 Offset error, ADC, 93 Offset sensor encoder, 363 Offset signals, amplifier, 49 Offset track encoder, 363 Offsetting circuitry, 114, 115 On-off control, On-off valve, 578 Op-amp, 38, 50 drift, 41 Open-circuit voltage, 29 Open-loop control, Open-loop gain, op-amp, 40 Operating interval, 152 Operating points, dc motor, 501 Operating principle, dc motor, 488 Operation of tactile sensors, 310 Operational amplifiers, 38 Opposed, binary transducer, 394 Optical coupling, 51 Optical displacement sensors, 184 Optical encoders, 359 Optical fiber tactile sensors, 313 Optical potentiometers, 183, 216 Optical sensors, 320 Optical tactile sensor, 310, 312 Optimization, transmission, 35 Order, filter, 56 Orifice plate flow sensors, 330 Orthotic devices, 25 Oscillators, 244 Wien-bridge, 109 Oscilloscopes, 129 digital, 132 Output impedance, 29, 133, 153, 159, 244 op-amp, 40 Output power, motor, 502 Overdamped, 150 Overlapped land, valve, 579 Owen bridge, 108 P Pan, tilt, and zoom, 17 Parameter measurement, motor, 516 Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C011 Final Proof page 665 9.12.2006 9:00pm Index Parametric errors, DAC, 86 Parts transfer mechanism, 485 Passive compliance, 317 Passive filters, 55, 138 Passive transducers, 208, 238 PCM, 72 Peak time, 147 Peak value, 149 Peak-hold circuits, 125 Percentage nonlinearity, 104 Percentage overshoot, 147 Perfect measurement device, 146 Performance control system, digital transducers, 395 potentiometer, 214 Performance characteristics, ADC, 92 Performance ratings, amplifier, 47 Performance specification, 145 frequency-domain, 152 Permanent-magnet ac tachometer, 242 Permanent-magnet stepper motor, 406 Permanent-magnet transducers, 238 Permeability, 498 Permittivity, 246 PFM, 71 Phase activation sequence, stepper, 408 Phase angle, 152, 155 Phase lead, 155 Phase margin, 153 Phase shifters, 119 Phase-locked control, 526, 528 Phases, stepper motor, 406 Photo FET, 322 Photo field effect transistors, 322 Photodetectors, 322 Photodiodes, 322 Photosensor encoder, 359 Physical realizability, 263 Physical resolution, encoder, 368 PID control, 7, 525, 596 Piezoelectric accelerometers, 255 compression-type, 256 frequency response, 256 Piezoelectric crystals, 326 Piezoelectric sensors, 253 accuracy, 260 Piezoelectric time constant, 259 Piezoelectric velocity transducer, 256 Piezoresistive property, 275 Piezoresistive tactile sensors, 314 Pin designation, op-amp, 39 Pinion, 643 Pin-slot transmission, 634 Piston–cylinder actuators, 583 665 Piston pressure sensors, 328 Piston pump, 574 Pitot tube flow sensors, 330 Planetary gear unit, 643 Plant, PLC, 11, 23, 569 PLZT, 253 PM stepper motor, 406 Pneumatic control systems, 598 Pneumatic flapper valve, 599 PO, 147 Poisson’s ratio, 274, 278 Polarity reversal, stepper, 409 Pole changing, 554, 560 Poles filter, 56 stepper motor, 406 Polynomial equations, 113 Polyvinylidene fluoride, 253 Poppet valve, 578 Position plus velocity feedback, 524 Position sensors fiber-optic, 321 laser interferometer, 322 ultrasonic, 327 Positioning platform, automated, 484 Positioning tables, 459 Potentiometer circuits, 114 strain gage, 276 Potentiometers, 211 optical, 183 performance, 214 sensitivity, 216 Power amplifiers, 42 Power consumption, 146 Power supply, current-regulated, 103 PPD control, 525, 528 Precision, 181 Pressure control valve, 590, 619 Pressure feedback, 591, 600 natural, 586 Pressure gain, 587 Pressure sensitivity, 580 Pressure sensors, 328 bellows, 328 Bourdon tube, 328 capsule, 328 diaphragm, 328 helical tube, 328 piston, 328 Pressure-regulating valves, 578 Primary winding, 221 Process control, 23 Programmable logic controllers, 11, 23, 569 Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C011 Final Proof 666 Sensors and Actuators: Control Systems Instrumentation Proportional control, hydraulic, 592 Proportional gain, Proportional output circuitry, 114, 116 Proximity sensors, 232 eddy current, 244 Proximity sensor encoders, 360 Proximity sensor tactile sensors, 310 Proximity, binary transducer, 394 p-type gages, 284 PTZ, 17 Pull-in curve, stepper, 457 Pull-out speed, stepper, 456, 458 Pull-out torque, stepper, 456, 459 Pulse delay, stepper damping, 445 Pulse generators, fluidic, 622 Pulse missing control, stepper, 450 Pulse reversal, stepper damping, 444 Pulse trains, 358 Pulse turn-off, stepper damping, 444 Pulse-code modulation, 72 Pulse-counting method, encoder, 371, 375 Pulse-frequency modulation, 71 Pulse-timing method, encoder, 371, 375 Pulse-width modulation, 70 Pump stroke-regulated hydraulic power, 619 Pump-controlled hydraulic actuators, 597 Pumps, 574 Pure transducers, 208 Push–pull displacement sensor, 252 PVDF, 253 PWM, 70 amplifiers, 529, 531, 534, 610 PZT, 253 Q Quad package, 38 Quadrature error, 222 Quadrature signals, 362, 366, 369, 372, 385, 390, 396 Quantization error, 72, 357, 381 ADC, 92 encoder, 381 Quartz crystal, 253 R Rack and pinion, 638 Radial play, encoder, 382 Radio frequency, 244 Random error, 180 Random variable, 179 Rare earth magnets, 494 Rate error, 237, 319, 354 Rating parameters, 159 sensor=transducer, 308 RCC, 317 page 666 9.12.2006 9:00pm Reactance, 246 Reaction dynamometers, 304 Reaction torque sensors, 303 Real-time signal analyzer, 128 Receiver, resolver, 236 Record length, 164 signal analysis, 129 Recording, encoder, 360 Rectangular package, 38 Rectangular window, 163 Rectification, 226 Recursive digital filters, 99 Reference frequency, 226 Reference pulse, 359 Reference voltage variations, DAC, 86 Reflective, binary transducer, 394 Reflex, binary transducer, 394 Relays, 569 Relay circuit, 341 Relief valve, 578 Reluctance encoder, 360 Reluctance, 221, 498 Remote-center compliance, 317 Repeatability, 180 Reset action, 148 Residual torque, stepper, 456 Resistance temperature detectors, 275, 333 Resistivity, 274 Resolution, 46, 129, 159 absolute encoder, 379 ADC, 80, 92 DAC, 80, 85 motion, 192 potentiometer, 215 spatial, 192 Resolvers, 233 digital, 385 Resonance-type band-pass filters, 64 Resonant frequency, 153, 155 Response time, tactile sensor, 309 Response, fast, 146 Right-hand triad, 489 Rigid spline, 632, 634, 636, 644 Ring gyroscope, 323 Rise time, 146 Robot joint, 345 Robot, Robotic arc welding, 341 Robotic manipulators, 644 Robustness, 3, 146 Rochelle salt, 255 Rolling mills, 588 Roll-off rate, filters, 58 Rotating magnetic field, 495, 544, 567 Rotation sensors, capacitive, 247 Rotatory potentiometers, 212 Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C011 Final Proof page 667 9.12.2006 9:00pm Index Rotatory-variable differential transducers, 230 Rotatory-variable differential transformers, 230 Rotors cage, 548 dc motor, 489 resolver, 233 wound, 548 Rotor output, resolver, 234 Rotor pole, 407 Rotor resistance control, 554, 559 Rotor stack misalignment, stepper, 426 Rotor stacks, stepper, 412 Rover mobile robot, 24 RTD, 275, 333 Run-down test, motor, 612 RVDT, 230 S S=H, 79, 95 Sagnac effect, 323 Sample mean, 190 Sample step, 170 Sample variance, 190 Sample-and-hold, 79 circuitry, 95 Sampling theorem, 165, 170 Saturation, 155 effect, 244 Saw-tooth signal, 123, 130 SC, 87 Schmitt trigger, 399 SCR, see Thyristor Seam tracking, arc welding, 341 Secondary winding, 221 Seebeck effect, 322 Selection, stepper motors, 456, 458 Self compensation, strain gage temperature, 287 Self-generating transducers, 208 Self-Induction transducers, 237 Self-tuning control, 159 Semiconductor strain gages, 283 Sensitivity requirement, strain-gage, 296 Sensitivity, 3, 159 capacitive sensor, 248 high, 146 piezoelectric, 253 potentiometer, 216 strain gage, 274, 279 strain gage bridge, 276 Sensors, 1, 207 active, 209 analog, 209 667 angular velocity, 250 cable extension, 393 differential displacement, 252 flow, 329 front-end auxiliary element, 210, 218 pressure, 328 rating parameters, 308 temperature, 332 thermofluid, 328 ultrasonic, 326 Sensor networks, embedded and distributed, 335 Sensor sensitivity, capacitive, 248 Sensory architectures, hierarchical, 335 Separately excited dc motor, 498, 500, 518, 532, 608 Series-wound motor, 503, 506, 509, 532, 538 Servomotors, dc, 513, 522, 529, 537, 553 Servovalves, 571, 574, 578, 585, 592, 596, 598, 600 pressure feedback, 600 multistage, 600 Settling time, 147, 148 DAC, 85 stepper, 435, 440 Shaft eccentricity, encoder, 382 Shaft encoders, 359 Hall-effect, 389 Shannon’s sampling theorem, 165 Short-circuit current, 29 Shunt-wound motor, 503, 506, 538 Side bands, 75 Side frequencies, 75 Side lobes, 164 Signal acquisition, tactile sensor, 311 Signal analyzer bandwidth, 129 Signal analyzers, 128 real-time, 128 Signal conditioning, 27 LVDT, 226 Signal sampling, 170 Signal-to-noise ratio, 215, 226 Signature verification, 344 Simple oscillator, 21, 148, 154 Single-phase ac motors, 566 Single-phase energization, stepper, 432 Single-stack steppers, 413 Single-stack VR steppers, 413 Sizing, motor, 541 Slew curve, stepper, 457 Slew rate amplifiers, 47, 50 stepper, 435, 459 Slewing motion, 435 Sliding contact encoder, 359 Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C011 Final Proof 668 page 668 9.12.2006 9:00pm Sensors and Actuators: Control Systems Instrumentation Slip, induction motor, 549 Slip ring, 239, 244 SNR, 215, 226 strain gage, 296 Soft-drink bottling plant, 22 Softening devices, 157 Software digital filters, 100 Software, linearization, 112 Solenoid, 569 Solenoid-actuated flow control valve, 620 Spatial resolution, 192 tactile sensors, 309 SPC, 190 Specifications motor, 537 time-domain, 146 Spectral lines, 128, 172 Spectrum analyzer, 128 Speed control system, 201 Speed, encoder, 375 Speed of response, 3, 150, 152 Speed profile, 462 Speed regulation, dc motor, 504 Speed sensors, capacitive, 250 Speed–torque curve, stepper, 456, 465 Splines, 113 Split-ring brush commutators, 491 Spool valve, 578 Spring-loaded accumulators, 598 Square root of sum of squares error, 182 SRSS error, 182 Stability, 3, 146, 150, 153 machine tool, 273 Stabilized voltage source, 244 Stamping, encoder, 360 Standard deviation, 190 Stand-still torque, stepper, 456 Start conversion, 87 Starting torque, stepper, 410, 456, 465 Start–stop curve, stepper, 457 Static calibration curve, 160 Static gain, 152, 165 Static linearity, 146 Static nonlinearities, 110, 155 Static position error, stepper, 438 Static torque dc motor, 491, 496 stepper, 433, 438, 443, 453, 456 three-phase, 439 Statistical process control, 179 Statistical process control, 190 Stator pole, 407 Stators, dc motor, 489 Stators, resolver, 233 Steady-state characteristics, dc motor, 499 Steady-state error, 8, 148 Steady-state performance, 152 Steady-state valve characteristics, 581 Steel rolling mill, 588 Step motor, see Stepper motor Step response, 148 motor, 517 Stepper motors, 405 applications, 456, 466 classification, 411 controller, 427, 450 detent position, 432 detent torque, 426, 457, 462 downramping, 436, 454, 458 driver, 427 feedback control, 452 holding torque, 406, 412, 426, 433, 447, 456, 459, 462 hybrid, 412, 425 linear, 471 miniature, 253 model-based control, 455 models, 446 no-load speed, 456 permanent-magnet, 406 phases, 406 poles, 406 principle, 405 pull-in curve, 457 pull-out speed, 456, 458 pull-out torque, 456, 459 residual torque, 456 selection, 456, 458 settling time, 435, 440 slew curve, 457 slew rate, 435, 459 speed–torque curve, 456, 465 stand-still torque, 456 starting torque, 410, 456, 465 start–stop curve, 457 static position error, 438 terminology, 456 time constant, 430 torque and motion, 432 torque characteristics, 456 torque control through switching, 454 two-phase, 406 upramping, 436, 454 Stepper motor damping, 439 pulse delay, 445 pulse reversal, 444 pulse turn-off, 444 Stepping motors, see Stepper motor Stepping sequence, PM motor, 408 Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C011 Final Proof page 669 9.12.2006 9:00pm Index Step-up gearing, encoder, 370, 374 Stiffness control, 270 Stiffness requirement, strain gage, 296 Stochastic error, 180 Strain capacity, strain gages, 295 Strain gages, 273 ballast circuit, 276 foil-type, 275 nonlinearity, 285 n-type, 285 potentiometer circuit, 276 p-type, 284 semiconductor, 283 sensitivity, 279 stiffness requirement, 296 strain capacity, 295 temperature coefficient of resistance, 287 temperature coefficient of sensitivity, 287 temperature self compensation, 287 Strain gage bridges, 276 constant, 277 calibration constant, 279 data acquisition, 282 sensitivity, 276 Strain-gage accelerometers, 275, 279 MEMS, 352 Strain-gage load cell, 278 Strain-gage material, 284 Strain-gage nonlinearity limit, 295 Strain-gage sensitivity requirement, 274, 296 Strain-gage torque sensors, 290, 315 design criteria, 297 location, 298 Stroke-regulated hydraulic power, 619 Structural components, 625 Structural limitations, encoder, 381 Successive approximation ADC, 87 Summer DAC, 81 Supervisory control, 207 Switches capacitive, 394 eddy current, 394 electromechanical, 394 Hall-effect, 394 magnetic, 394 photoelectric, 394 ultrasonic, 394 Switching sequence, stepper, 408 Switching transients, 239 Synchro transformer, 235 Synchronous motors, 567 control, 568 three-phase, 306 Synchronous speed, 549, 558, 563, 568 669 System identification, 207 Systematic error, 148, 180 T T package, 38 Table lookup, 112 Tachogenerators, 239 Tachometers ac, 167 ac induction, 243 ac permanent-magnet, 242 dc, 238 design, 239 digital, 242, 387 gain, 241 leakage inductance, 242 load impedance, 242 mechanical, 165 modeling, 239 Tactile sensing, 308 Tactile sensors, 191 conductive elastomer, 310 construction, 310 deflection sensor, 310 durability, 309 energy dissipation, 309 fiber-optic, 313 force resolution, 309 force sensitivity, 309 hysteresis, 309 operation, 310 optical sensor, 310, 312 piezoresistive, 314 proximity sensor, 310 requirements, 309 robustness, 309 sensitivity, 350 signal acquisition, 311 slip detection, 309 spatial resolution, 309 strain-gage, 315 Taylor series expansion, 182 Temperature coefficient of sensitivity, strain gage, 287 Temperature coefficients of resistance, 333 strain gage, 287 Temperature compensation, automatic, 287 Temperature drift, amplifiers, 48 Temperature sensors, 332 RTD, 333 thermistor, 333 thermocouple, 332 Terminal device, 200 Termination resistance, 33 Terminology, stepper, 456 Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C011 Final Proof 670 page 670 9.12.2006 9:00pm Sensors and Actuators: Control Systems Instrumentation Thermistor, 275, 333 Thermocouples, 332 cold junction, 332 hot junction, 332 Thermofluid sensors, 328 Thermometers, bi-metal strip, 334 Thermostat, 334 Thevenin equivalent circuit, 253 Thevenin’s theorem, 133 Three-phase static torque, 439 Three-phase synchronous motor, 306 Three-phase VR steppers, 413 Three-phase windings, 546 Three-slider CVT, 640 Three-step drive sequence, stepper, 437 Through variables, 29 Through, binary transducer, 394 Thyristors, 532, 536, 554, 556 Time constant, 149, 166 derivative, electrical, 241 hydraulic, 587, 591 integral, mechanical, 241 motor, 515, 521, 523, 591 piezoelectric, 259 stepper motor, 430 tachometer, 241 Time of flight displacement sensors, 327 Time-domain specifications, 146 Timer, 80 Tool–workpiece interface, 273 Toothed ferromagnetic stators, 497 Toothed poles, stepper, 416, 419 Tooth-meshing frequency, 77 Torque amplifiers, motor, 530 Torque characteristics, stepper, 456 Torque control through switching, stepper, 454 Torque equation, stepper motors, 449 Torque motion characteristics, stepper, 432 Torque motors, 497, 616 Torque sensors, 289 bandwidth analysis, 294 bending element, 301 deflection type, 301 design criteria, 292, 295, 297 direct-deflection, 301 location, 298 motor current, 305 reaction type, 303 strain-gage, 290 variable-reluctance, 303 Torque source, 34 Torque–speed relationship, 550 Torsion member, 291 Torsional rigidity, 292 Track eccentricity, encoder, 382 Track, encoder, 360 Tracking filters, 55 Traction drives, 627, 634, 646 Traction-drive joint, 645 Transducers, 1, 208 active, 209 analog, 209 binary, 394 eddy current, 244 passive, 208 permanent-magnet, 238 pure, 208 self-generating, 208 self-induction, 237 variable-capacitance, 246 Transducer rating parameters, 308 Transducer time constant, 241 Transfer function feedback, 153 forward, 153 loop, 154 Transfer-function model, induction motor, 561 Transient operation, dc motor, 495 Translator, stepper motor, 409, 427, 431, 450, 453, 458 Transmissibility curves, 159 Transmission components, 625, 627 Transmission level, filter, 162 Transmission, continuously variable, 637 Transmitter, resolver, 236 Triggering, oscilloscope, 129 True value, 180 Truncation, data, 164 Tundish, 201 Turbine flow meters, 330 Two-axis hydraulic positioning, 621 Two-phase induction motors, 563 Two-phase stepper motors, 406 Two-phase two-pole stepper, 416 Two-port device, 29 Two-port system, 266 Two-slider CVT, 639 U Ultrasonic flow meters, 330 Ultrasonic position sensors, 327 Ultrasonic sensors, 326 Ultrasound, extrinsic method, 326 Ultrasound, intrinsic method, 326 Undamped natural frequency, 148 Underdamped, 150 Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C011 Final Proof page 671 9.12.2006 9:00pm Index Underlapped land, valve, 579 Unequal-pitch steppers, 412 multiple-stack, 424 Unifilar windings, 410 Unit step, 148 Unknown inputs, disturbances, 207 Upramping, stepper, 436, 454 Useful frequency range, 152, 159, 164 V Valves, 577 flapper, 599, 601 flow control, 618 Valve actuators, 569 Valve characteristics, steady-state, 581 Vane pump, 574 Variable-capacitance transducers, 246 Variable-inductance transducers, 220 Variable-reluctance stepper motor, 409, 497 Variable-reluctance torque sensor, 303 Variance, 190 VCC, 124 VCO, 122 Velocity amplifier, motor, 530 Velocity error, 237 Velocity feedback, 524, 591 natural, 586 Velocity measurement absolute encoder, 380 encoder, 371, 372 Velocity transducers capacitive, 250 piezoelectric, 256, 260 rectilinear, 238 Venturi meter flow sensor, 330 VFC, 119, 121 671 Vibration monitoring, 141 Vibration testing system, 25, 253 Voltage amplifier, 42 Voltage constant, 239 Voltage control, 613 motor, 554, 556 Voltage follower, 42, 46, 56, 63, 67, 95, 126, 133, 137 Voltage ripple, 242 Voltage sensitivity, 253 Voltage source, stabilized, 244 Voltage-controlled oscillator, 122 Voltage-to-current converter, 124 Voltage-to-frequency converters, 119, 121 VR stepper motor, 409 W Wave generators, 632, 634, 636, 644 Weighted-resistor DAC, 81 Wheatstone bridges, 101 strain gage, 276 Whole-word encoder, 359 Wien-bridge oscillator, 109 Window, rectangular, 163 Wiper arm, 211 Wood drying kiln, Wound rotor, 548 X x–y tables, 459 Z Zener diodes, 119 Zero drift, 159 Zoom analysis, 129 Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C011 Final Proof page 672 9.12.2006 9:00pm Clarence W de Silva/Sensors and Actuators: Control Systems Instrumentation 44834_C012 Final Proof page 11.12.2006 10:23am Units and Conversions (Approximate) cm ¼ 1=2.54 in ¼ 0.39 in rad ¼ 57.38 rpm ¼ 0.105 rad=s g ¼ 9.8 m=s2 ¼ 32.2 ft=s2 ¼ 386 in=s2 kg ¼ 2.205 lb kg.m2 (kilogram-meter-square) ¼ 5.467 oz.in2 (ounce-inch-square) ¼ 8.85 lb.in.s2 N=m ¼ 5.71 Â 10À3 lbf=in N=m=s ¼ 5.71 Â 10À3 lbf=in=s N.m (Newton-meter) ¼ 141.6 oz.in (ounce-inch) J ¼ Nm ¼ 0.948 Â 10À3 Btu ¼ 0.278 kWh hp (horse power) ¼ 746 w (watt) ¼ 550 ft lbf kPa ¼ Â 103 Pa ¼ Â 103 N=m2 ¼ 0.154 psi ¼ Â 102 bar gal=min ¼ 3.8 L=min Metric Prefixes: giga mega kilo milli micro nano pico G M k m m n p 109 106 103 10À3 10À6 10À9 10À12 ... control, and sensors and actuators Clarence W de Silva /Sensors and Actuators: Control Systems Instrumentation 44834_C000 Final Proof page xiv 19.12.2006 1:34pm Clarence W de Silva /Sensors and Actuators: ... Silva /Sensors and Actuators: Control Systems Instrumentation 44834_C000 Final Proof page i 19.12.2006 1:34pm SENSORS AND ACTUATORS Control Systems Instrumentation Clarence W de Silva /Sensors and Actuators: ... switches, and analog sensors such as RTD temperature sensors, diaphragm-type pressure sensors, piezoelectric accelerometers, and strain-gauge load sensors) and a set of output devices (e.g., actuators