Tài liệu Mechatronics (Hugh 2001) pptx

Copyright © 1993-2001, Hugh Jack

Engineer On a Disk

Overview: This note set is part of a larger collection of materials available at http://claymore.engi￾neer.gvsu.edu. You are welcome to use the material under the license provided at http://clay￾more.engineer.gvsu.edu/eod/global/copyrght.html. As always any feedback you can provide

will be welcomed.

Copyright © 1993-2001, Hugh Jack

email: [email protected]

phone: (616) 771-6755

fax: (616) 336-7215

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1. TABLE OF CONTENTS

TABLE OF CONTENTS.......................................................................................................... 2

OVERVIEW ............................................................................................................................. 8

PROCESS CONTROL ............................................................................................................. 9

INTRODUCTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9

CONTROL SYSTEM CHARACTERISTICS - - - - - - - - - - - - - - - - - - - - - - - - - 10

CONTROLLER TYPES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 11

PROCESS DIAGRAMS AND SYMBOLS - - - - - - - - - - - - - - - - - - - - - - - - - - - 11

PRACTICE QUESTIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 11

DISCRETE CONTROLLER DESIGN .................................................................................. 12

POSITIONING CONTROLLERS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 12

TRACKING - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 22

DISTURBANCE RESISTANT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 25

MULTI-CONTROLLER SYSTEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 28

SAMPLE TIME - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 34

SUMMARY - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 35

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 36

DISCRETE SYSTEMS .......................................................................................................... 38

DISCRETE SYSTEM MODELLING WITH EQUATIONS - - - - - - - - - - - - - - - 38

DISCRETE CONTROLLERS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 48

BLOCK DIAGRAMS AND TRANSFER FUNCTIONS - - - - - - - - - - - - - - - - - - 56

SAMPLING FUNCTIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 68

SYSTEM RESPONSE - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 72

STEADY STATE ERROR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 76

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 78

PETRI NETS .......................................................................................................................... 81

INTRODUCTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 81

IMPLEMENTATION FOR A PLC - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 87

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 91

CONTINUOUS CONTROL SYSTEMS................................................................................ 92

CONTROL SYSTEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 92

ROOT-LOCUS PLOTS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 113

DESIGN OF CONTINUOUS CONTROLLERS - - - - - - - - - - - - - - - - - - - - - - 121

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 121

FUZZY LOGIC .................................................................................................................... 126

COMMERCIAL CONTROLLERS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 130

REFERENCES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 130

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 131

MECHATRONICS CIRCUITS............................................................................................ 132

POWER SWITCHING - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 132

USER INPUT/OUTPUT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 132

HARDWARE BASED CONTROLLERS............................................................................ 134

CIRCUITS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 134

FLUIDICS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 134

PNEUMATICS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 134

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PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 134

EMBEDDED CONTROLLERS........................................................................................... 135

TYPES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 135

CONTROLLER DESIGN EXAMPLE - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 135

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 135

DISCRETE SENSORS......................................................................................................... 136

INTRODUCTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 136

SENSOR WIRING - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 136

CONTACT DETECTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 143

PROXIMITY DETECTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 143

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 156

CONTINUOUS SENSORS.................................................................................................. 159

INPUT ISSUES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 159

SENSOR TYPES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 163

ANGULAR POSITION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 166

LINEAR POSITION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 170

VELOCITY - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 173

ACCELERATION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 174

FORCE/MOMENT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 176

FLOW RATE - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 181

TEMPERATURE - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 182

SOUND - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 185

LIGHT INTENSITY - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 186

PRESSURE - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 187

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 187

REFERENCES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 188

ACTUATORS ...................................................................................................................... 189

ACTUATOR TYPES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 189

DISCRETE ACTUATORS .................................................................................................. 189

INTRODUCTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 189

TYPES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 190

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 195

CONTINUOUS ACTUATORS ........................................................................................... 196

ACTUATOR CONTROL - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 196

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 202

PROGRAMMABLE LOGIC CONTROLLERS.................................................................. 203

BASIC PLCs - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 203

A SIMPLE EXAMPLE - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 212

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 212

PLC CONNECTION ............................................................................................................ 215

SWITCHED INPUTS AND OUTPUTS - - - - - - - - - - - - - - - - - - - - - - - - - - - - 215

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 226

PLC OPERATION ............................................................................................................... 232

PLC ORGANIZATION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 232

PLC STATUS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 233

MEMORY TYPES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 234

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SOFTWARE BASED PLCS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 234

PROGRAMMING STANDARDS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 234

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 236

SWITCHING LOGIC........................................................................................................... 238

BOOLEAN ALGEBRA - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 238

DISCRETE LOGIC - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 240

SIMPLIFYING BOOLEAN EQUATIONS - - - - - - - - - - - - - - - - - - - - - - - - - - 247

ADDITIONAL TOPICS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 250

DESIGN CASES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 253

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 254

NUMBERING ...................................................................................................................... 271

INTRODUCTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 271

DATA VALUES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 272

DATA CHARACTERIZATION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 281

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 283

EVENT BASED LOGIC ...................................................................................................... 286

INTRODUCTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 286

TIMERS, COUNTERS, FLIP-FLOPS, LATCHES - - - - - - - - - - - - - - - - - - - - - 286

PROGRAM DESIGN METHODS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 303

DESIGN CASES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 306

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 314

SEQUENTIAL LOGIC DESIGN......................................................................................... 321

SCRIPTS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 321

FLOW CHARTS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 325

STATE BASED MODELLING - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 335

PARALLEL PROCESS FLOWCHARTS - - - - - - - - - - - - - - - - - - - - - - - - - - - 360

SEQUENTIAL LOGIC CIRCUITS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 370

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 372

ADVANCED LADDER LOGIC FUNCTIONS .................................................................. 406

ADDRESSING - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 406

INSTRUCTION TYPES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 412

DESIGN TECHNIQUES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 440

DESIGN CASES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 442

FUNCTION REFERENCE - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 445

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 471

PLC PROGRAMMING........................................................................................................ 478

PROGRAMMING STANDARDS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 478

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 480

STRUCTURED TEXT PROGRAMMING.......................................................................... 481

INTRODUCTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 481

THE LANGUAGE - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 481

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 494

INSTRUCTION LIST PROGRAMMING........................................................................... 495

INTRODUCTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 495

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 498

FUNCTION BLOCK PROGRAMMING ............................................................................ 500

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INTRODUCTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 500

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 501

ANALOG INPUTS AND OUTPUTS.................................................................................. 503

ANALOG INPUTS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 503

ANALOG OUTPUTS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 511

DESIGN CASES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 514

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 515

CONTINUOUS CONTROL................................................................................................. 521

CONTROLLING CONTINUOUS SYSTEMS - - - - - - - - - - - - - - - - - - - - - - - - 522

CONTROLLING DISCRETE SYSTEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - 523

CONTROL SYSTEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 523

DESIGN CASES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 527

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 527

PLC DATA COMMUNICATION ....................................................................................... 528

COMPUTER COMMUNICATIONS CATEGORIES - - - - - - - - - - - - - - - - - - - 528

THE HISTORY - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 529

WITH PLCs - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 529

SERIAL COMMUNICATIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 530

PARALLEL - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 541

NETWORKS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 541

BUS TYPES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 554

DESIGN CASES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 562

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 563

HUMAN MACHINE INTERFACES (HMI) ....................................................................... 566

INTRODUCTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 566

HMI/MMI DESIGN - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 567

DESIGN CASES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 567

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 568

DESIGNING LARGE SYSTEMS ....................................................................................... 569

PROGRAMMING - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 569

DOCUMENTATION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 570

PLC PROGRAM DESIGN FORMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 571

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 578

IMPLEMENTATION........................................................................................................... 579

ELECTRICAL - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 579

SAFETY - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 591

PROCESS MODELLING .................................................................................................... 594

REFERENCES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 597

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 597

SELECTING A PLC ............................................................................................................ 599

SPECIAL I/O MODULES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 603

PLC PROGRAMMING LANGUAGES - - - - - - - - - - - - - - - - - - - - - - - - - - - - 607

ISSUES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 607

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 607

PLC REFERENCES ............................................................................................................. 609

SUPPLIERS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 609

page 6

PROFESSIONAL INTEREST GROUPS - - - - - - - - - - - - - - - - - - - - - - - - - - - 610

PLC/DISCRETE CONTROL REFERENCES - - - - - - - - - - - - - - - - - - - - - - - - 610

USING THE OMRON DEMO PACKAGE......................................................................... 614

OVERVIEW - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 614

REFERENCE GUIDE FOR OMRON PLC DEMO SOFTWARE - - - - - - - - - - - 618

INDUSTRIAL ROBOTICS.................................................................................................. 619

INTRODUCTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 619

ROBOT TYPES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 632

ROBOT APPLICATIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 663

END OF ARM TOOLING (EOAT) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 666

ADVANCED TOPICS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 675

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 676

ROBOTIC PATH PLANNING METHODS........................................................................ 690

INTRODUCTION: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 690

GENERAL REQUIREMENTS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 696

SETUP EVALUATION CRITERIA - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 704

METHOD EVALUATION CRITERIA - - - - - - - - - - - - - - - - - - - - - - - - - - - - 709

IMPLEMENTATION EVALUATION CRITERIA - - - - - - - - - - - - - - - - - - - - 716

OTHER AREAS OF INTEREST - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 719

COMPARISONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 720

CONCLUSIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 722

APPENDIX A - OPTIMIZATION TECHNIQUES - - - - - - - - - - - - - - - - - - - - 722

APPENDIX B - SPATIAL PLANNING - - - - - - - - - - - - - - - - - - - - - - - - - - - 725

APPENDIX C - TRANSFORMED SPACE - - - - - - - - - - - - - - - - - - - - - - - - - 731

APPENDIX D - FIELD METHODS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 738

APPENDIX E - NEW AND ADVANCED TOPICS - - - - - - - - - - - - - - - - - - - 740

REFERENCES: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 741

ROBOTIC MECHANISMS ................................................................................................. 746

KINEMATICS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 746

MECHANISMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 749

ACTUATORS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 750

PATH PLANNING - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 752

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 758

MOTION PLANNING AND TRAJECTORY CONTROL ................................................. 763

TRAJECTORY CONTROL - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 763

PATH PLANNING - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 767

MOTION CONTROLLERS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 771

SPECIAL ISSUES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 774

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 776

MICROBOT OVERVIEW - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 778

CRS PLUS ROBOT OVERVIEW - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 778

BASIC DEMONSTRATION STEPS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 779

CNC MACHINES ................................................................................................................ 781

MACHINE AXES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 781

NUMERICAL CONTROL (NC) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 781

EXAMPLES OF EQUIPMENT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 785

page 7

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 788

CNC PROGRAMMING....................................................................................................... 789

G-CODES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 790

APT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 798

PROPRIETARY NC CODES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 801

GRAPHICAL PART PROGRAMMING - - - - - - - - - - - - - - - - - - - - - - - - - - - - 802

NC CUTTER PATHS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 803

NC CONTROLLERS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 805

PRACTICE PROBLEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 805

page 8

2. OVERVIEW

Mechatronics deals with the long ignored union of machanical and electrical systems.

page 9

3. PROCESS CONTROL

• To put it simply - we figure out how the process behaves naturally, we determine how we want it

to behave, and we insert a controller to make it do what we want.

3.1 INTRODUCTION

• CONTROL - Using artificial means to manipulate the world - with a particular goal.

• Continuous - the values to be controlled change smoothly. e.g. the speed of a car

• Discrete - The value to be controlled are easily described as on-off. e.g. the car motor is on-off

(like basic pneumatics). NOTE: all systems are continuous (Except for Heisenberg’s electrons)

but they can be treated as discrete for simplicity.

• Linear - Can be described with a simple differential equation (not a very accurate explanation).

e.g. a car can be driving around a track and can pass same the same spot at a constant

velocity. But, the longer the car runs, the mass decreases, and it travels faster, but

requires less gas, .......... etc. Basically, the math gets tougher, and the problem

becomes non-linear.

- This is the preferred starting point for simplicity, and a common approximation for real

world problems.

• Non-Linear - Not Linear. This is how the world works, but is very complicated. Especially when

trying to do mathematical approximations. (Note: if the coefficients in a differential equation

change it is non-linear)

CONTROL

CONTINUOUS DISCRETE

LINEAR NON_LINEAR CONDITIONAL SEQUENTIAL

e.g. PID

e.g. MRAC

e.g. FUZZY LOGIC

BOOLEAN

TEMPORAL

e.g. TIMERS

e.g. COUNTERS

EVENT BASED

EXPERT SYSTEMS

page 10

• Temporal/sequential - the controller must not just keep track of things that changes, but it must

know the time, or how long since something happened.

• e.g.

non-linear - as rocket approaches sun, gravity increases, so control must change.

linear - We are driving the perfect car with no friction, with no drag, and can predict how it

will work perfectly.

discrete - “When I do this, that always happens!” For example, when the power is turned

on, the press closes!

How to tell the difference? An elevator is the perfect example.

Discrete

1. The elevator must move towards a floor when a button is pushed.

2. The elevator must open a door when it is at a floor.

3. It must have the door closed before it moves.

etc.

Linear (our approximation commonly used in industry) NOTE: each floor will have a cer￾tain motor position, and we know what that position is.

1. If the desired position changes to a new value, accelerate quickly

towards the new position.

2. As the elevator approaches the correct position, slow down.

Non-linear (not yet common in industry) e.g. Fuzzy logic, Neural Networks, Adaptive

Control

1 Accelerate slowly to start.

2. Decelerate as you approach the final position.

3. Allow faster motion while moving.

4. Compensate for cable stretch, and changing spring constant, etc.

3.2 CONTROL SYSTEM CHARACTERISTICS

• Control systems are present in most systems we see. Example - elevator height.

• Some systems are naturally unstable and tend to self destruct. Example - balanced broom.

• Other systems are self regulating, and tend to some stable state - these are good candidates for

open loop control. Example - city water tank

• Other systems need some sort of regulation mechanisms added, these are called closed loop sys￾tems. Example - car cruise control

page 11

• If a system is simple we will say that it is linear. Example - perfect elevator

• A system can be subject to complicating factors that make it difficult/impossible to model math￾ematically. Example - elevator in tall building with stretchy cable

• If a system has switched states it can be described as discrete. Example - buttons to call elevator,

open/close doors

• Temporal/sequential systems can change over time, this requires sequential control. Example -

washing machine

3.3 CONTROLLER TYPES

- PLCs

- embedded controls

- PCs

- hardwired

3.4 PROCESS DIAGRAMS AND SYMBOLS

3.5 PRACTICE QUESTIONS

1. Consider a heater in your house, how can different forms of control be applied to this problem?

2. Why is discrete control so popular when continuous control allows more precision?

page 12

4. DISCRETE CONTROLLER DESIGN

• In controller design we try to meet some objective. Typical objectives include,

- positioning - for moving from position to position, where the setpoint is changed sud￾denly

deadbeat control

first order

- tracking - for following paths where setpoints are constantly changing

first order

- disturbance resistant - unexpected variations can be compensated for

step response

- multi-stage - for complex systems that need small errors

feed forward disturbance - can reduce effects of disturbances

feed forward command - to follow complex motions

cascade - a controller that examines intermediate steps of a process

• typical constraints to be developed are,

- stability - does not diverge over time

- stability - sampling period is short enough (no-aliasing)

- realizable - does not refer to future values

4.1 POSITIONING CONTROLLERS

• In these systems we will focus on how the output relates to the input.

• These techniques work best with simple systems that require a jump from one setpoint to

another.

• The general procedure to design a controller is,

1. Model the process (i.e., find Gp)

2. Determine the control objective (i.e. select the desired system response Gdr)

3. Substitute these into the equation below and solve for the controller transfer function,

4. Check the equation for practicality and stability

5. Develop the control equation for the computer

Gdr( ) B

cn

rn

---- Gc( ) B Gp( ) B

1 + Gc( ) B Gp( ) B = = ----------------------------------------

Gc( ) B

cn

rn

---- 1

Gp( ) B ---------------     Gdr( ) B

1 – Gdr( ) B --------------------------     = =

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6. Write the computer program

• Try to derive the expression given above,

4.1.1 Dead Beat Control

• It is possible (for a first order process) to match the output function to the input function in one

step.

• The desired function is,

• Given the process model below, design a deadbeat controller,

Gdr( ) B

cn

rn

---- Gc( ) B Gp( ) B

1 + Gc( ) B Gp( ) B = = ----------------------------------------

cn rn – 1 =

Gdr( ) B

cn

rn

= = ---- B T

desired posn

actual posn

page 14

• Trying to eliminate the error in one step can require an extremely high (power) gain. When this

gain is excessive we may use a less powerful controller.

4.1.2 Programming Examples

• The following programs are examples of methods for programming using a few common lan￾guages.

• These examples are for the Computer Boards DAS08-AOM board (The boards we used in the

lab with Labview).

• Please note that these programs have not been debugged.

Gp( ) B B

1 0.5 – B = --------------------

page 15

4.1.2.1 - BASIC

• A simple example of the deadbeat controller is given below. This can be converted to many of

the ‘modern’ version of basic that have appeared. Comments have been added to help clarify

the operation

4.1.2.2 - C

• The example program below should implement the deadbeat controller example given in this

section,

10 REM a control loop for the deadbeat controller example for 12 bit input and output

15 REM Written by H.Jack, July 17, 1997 - Not debugged

20 BASE = 330H; REM the base address for the card

20 T = 0.1; REM control system time step

40 M_LAST = 0; REM the current output is zero

50 E_LAST = 0; REM the current error

60 INPUT “ENTER SETPOINT [0 - 4095]” , R; REM get a setpoint

70 DO ; REM start the control loop

80 OUT BASE+2, 0; REM start the a to d conversion

90 WAIT T; REM an operating system specific timing function

100 C_HIGH = INP BASE+0; REM read current position most significant 8 bits

110 C_LOW = INP BASE+1; REM read current position least significant 4 bits

120 C_NOW = C_LOW/16 + C_HIGH*16

130 E_NOW = R - C_NOW; REM calculate the error

140 M_NOW = M_LAST + E_NOW - 0.5*E_LAST; REM the controller equation

150 IF (M_NOW < 0) THEN M_NOW = 0; REM prevent out of range case

160 IF (M_NOW > 4095) THEN M_NOW = 4095; REM prevent out of range case

170 M_HIGH = INT(M_NOW/256) ; REM find the 4 high bits of the 12 bit word

180 M_LOW = M_NOW - 256*M_HIGH; REM isolate the low 8 bits

190 OUT BASE+4, (M_LOW); REM set 8 low bits

200 OUT BASE+5, (M_HIGH); REM set 4 high bits

210 M_LAST = M_NOW; E_LAST = E_NOW; REM current values become last values

220 LOOP WHILE(ABS(E) < 0.001); REM continue looping until the error is small