Introduction to Robotics in CIM Systems Fifth Edition James A. Rehg The Pennsylvania State University Altoona, Pennsylvania Prentice Hall Upper Saddle River, New Jersey Columbus, Ohio
Contents Introduction to Industrial Robots 1 Chapter Goals and Objectives 1 1-1 Introduction 1 Career Spotlight 2 1-2 History of the Industry 2 1-3 Fifty-year-old Industry 5 1-4 Integrated Systems Meeting the External and Internal Challenges 7 External Challenges, 7 Internal Challenge, 10 Meeting the Internal Challenge, 11 1-5 The Problem and a Solution 18 1-6 Definition of Robotics and Computer-Integrated Manufacturing 19 1-7 Manufacturing System Classification 21 Project, 21 Job Shop, 23 Repetitive, 23 Line, 23 Continuous, 23 1-8 Robot Systems 25 Robot Hardware, 25 XIII
Mechanical Arm, 25 Production Tooling, 27 External Power Source, 27 Robot Controller, 29 Teach Stations, 30 ABB Controller Interface, 31 1-9 Some Basic Terms 32 1-10 Robot Safety Guidelines 42 Work Cell Safety Design Requirements, 43 Guidelines for Safe Robot Use, 43 1-11 Robot Standards 46 R15 Standards, 46 A15 Standards, 47 1-12 Summary 47 Questions 49 Problems 50 Projects 51 Robot Classification 53 Chapter Goals and Objectives 53 Career Spotlight 54 2-1 Introduction 54 2-2 Robot Arm Geometry 55 Cartesian Geometry, 55 Cylindrical Geometry, 58 Spherical Geometry, 60 Articulated Geometry, 63 Selective Compliance Articulated Robot Arm (SCARA), 66 Horizontally Base-jointed Arm, 66 2-3 Power Sources 67 Hydraulic Power, 67 Pneumatic Power, 70 Electric Power, 70 2-4 Drive Systems 73 Torque, 73 Belts, 74 Chains, 77
Gear Drives, 77 Gear Error, 81 Ball Screw Drives, 81 Harmonic Drives, 83 2-5 Application Areas 84 Assembly, 86 Nonassembly, 86 2-6 Control Techniques 87 Closed-loop Systems, 87 Position Sensors, 88 Open-loop Systems, 98 2-7 Path Control 102 Stop-to-stop Path Control, 104 Point-to-point Control, 104 Controlled Path, 107 Continuous Path, 108 2-8 Design Guidelines 109 Robot Selection Criteria, 109 Robot Survey, 110 2-9 Classification by the International Standards Organization (ISO) 112 Sequenced, 112 Trajectory, 112 Adaptive, 112 Teleoperated, 112 2-10 Summary 112 Questions 113 Problems 115 Projects and Case Study Problems 116 Automated Work Cells and CIM Systems 119 Chapter Goals and Objectives 119 Career Spotlight 120 3-1 Introduction 120 3-2 The CIM Implementation Process 121 Step 1: Assessment of Enterprise Technology, Human Resources, and Systems, 122 Step 2: Simplification Elimination of Waste, 123 Step 3: Implementation with Performance Measures, 125
3-3 Making the CIM Process Work 129 3-4 Automated Production 130 3-5 Flexible Automation 132 3-6 Fixed Automation 137 In-line Fixed Automation, 137 Rotary-type Fixed Automation, 138 3-7 Work-cell Design Checklist 138 3-8 Implementing Automated Work Cells 139 New versus Existing Production Machines, 139 Fixed versus Flexible Automation, 140 3-9 System Troubleshooting and Problem Solving 141 Introduction to Troubleshooting, 141 Hardware versus Software Troubleshooting, 142 Troubleshooting Techniques, 143 Block Diagrams, 144 Bracketing, 146 Signal Flow, 147 Signal Flow Analysis, 149 Information Funneling, 150 Symptoms and Use of System Data, 153 Troubleshooting Sequence, 154 Multiple Failures, 154 3-10 Summary 155 Questions 156 Problems 157 Projects and Case Study Problems 158 4 End-of-Arm Tooling 160 Chapter Goals and Objectives 160 Career Spotlight 161 4-1 Introduction 161 4-2 Standard Grippers 162 Gripping Force, 166 Minimum Gripper Force, 168 4-3 Vacuum Grippers 171 Lifting Capacity, 171 System Components, 174 xvi Contents
Vacuum Surfaces, 176 Vacuum Suckers, 176 4-4 Magnetic Grippers 177 4-5 Air-pressure Grippers 177 Gripping Force, 180 4-6 Special-purpose Grippers 182 4-7 Gripper Selection and System Intelligence 183 4-8 Special-purpose Tools 183 4-9 Robot Assembly 183 4-10 Compliance 184 Active Compliance, 186 Active Compliance Applications, 187 Passive Compliance, 188 4-11 Multiple End-effector Systems 191 Wrist Interface, 191 Multiple-gripper Systems, 192 4-12 Collision Systems 195 Breakable Link Devices, 195 Spring and Pneumatic Collision Devices, 196 4-13 Summary 197 Questions 198 Problems 198 Projects and Case Study Problems 200 Automation Sensors 202 Chapter Goals and Objectives 202 Career Spotlight 203 5-1 Introduction 203 Discrete Sensors, 204 Analog Sensors, 205 5-2 Contact Sensors 205 Discrete Devices, 205 Dogs, 207 Artificial Skin, 210 5-3 Noncontact Sensors 212 Proximity Sensors, 212 Inductive Sensor Operation, 217
Capacitive Sensors, 225 Photoelectric Sensors, 226 5-4 Sensor Selection Checklist 236 5-5 Smart Sensor Systems 236 DeviceNet Network, 236 5-6 Process Sensors 239 5-7 Troubleshooting Sensor Systems 239 Troubleshooting Tips for Proximity Sensors, 241 Troubleshooting Tips for Photoelectric Sensors, 243 5-8 Summary 245 Questions 246 Problems 247 Projects and Case Study Problems 248 6 Work-Cell Support Systems 250 Chapter Goals and Objectives 250 6-1 Introduction 250 Career Spotlight 251 6-2 Machine Vision Systems 251 Vision Standards, 252 Vision System Components, 252 Image Measurement, 256 Image Analysis, 256 Image Recognition, 258 6-3 Lighting for Machine Vision 259 Selection of the Light Source, 259 Lighting Techniques, 259 Illumination Sources, 261 6-4 Material Handling 262 Automated Transfer Systems, 262 Automatic Storage and Retrieval Systems, 266 6-5 Part Feeding 268 Gravity Feeders, 268 Magazine Feeders, 269 Tape Feeders, 269 Waffle-tray Feeders, 269 Vibratory Feeders, 271 xviii Contents
6-6 Inspection 272 6-7 Automatic Tracking 272 6-8 Summary 275 Questions 276 Projects and Case Study Problems 277 Robot and System Integration 278 Chapter Goals and Objectives 278 Career Spotlight 279 7-1 Introduction 279 7-2 System Overview 281 Hardware Overview, 282 Software Overview, 282 7-3 Work-cell Architecture 283 Cell Controllers, 283 Cell Control Software Structure, 283 Work-cell Management Software, 284 7-4 Programmable Logic Controllers 285 PLC System Components, 285 Basic PLC System Operation, 286 7-5 Computer Numerical Control 289 7-6 Controller Architecture 290 Nonservo Robot Controllers, 290 Servo Robot Controllers, 292 7-7 Interfaces 295 Simple Sensor Interface, 295 Simple Sensor Interface Design, 296 Complex Sensor Interface, 298 Enterprise Data Interface, 300 7-8 An Integrated System 300 Machining Cell, 302 Assembly Cell, 302 Signal Types, 302 Work-cell Controller, 303 Programmable Logic Controller, 303 7-9 Summary 304 Questions 304 Projects and Case Study Problems 305
8 Work-Cell Programming 306 Chapter Goals and Objectives 306 8-1 Introduction 306 Career Spotlight 307 8-2 Work-Cell Controller Programming 308 Software Developed In-house, 309 Enabler Software, 309 OSI Solution, 310 8-3 Programming Sequential Cell Activity 311 PLC Programming, 311 Other Sequential Programming Options, 314 8-4 Robot Language Development 315 8-5 Language Classification 316 Joint-control Languages, 316 Primitive Motion Languages, 317 Structured Programming Languages, 318 Task-oriented Languages, 318 8-6 Robot Program Fundamentals 319 Translation or Programmed Points, 319 Programmed Statements, 321 8-7 Translation or Position Points for Servo Robots 322 Reference Frames, 322 Programming Servo Robot Translation Points, 324 Programming Nonservo Robot Translation Points, 329 8-8 Program Statements for Servo Robots 329 Basic Program Structure Step 1, 329 Process Analysis Step 2, 330 Tasks and Subtasks Step 3, 330 Task Point Graph Step 4, 331 System Variables Step 5, 331 Write and Enter the Program Step 6, 331 Teach the Translation Points Step 7, 331 Test and Debug the Program Step 8, 333 On-line and Off-line Programming, 333 8-9 Programming a Servo Robot 334 Command Modes, 335 Coordinate Systems, 335 xx Contents
Data Types, 336 Axis Control Commands, 336 I/O Control and Program Flow Commands, 338 8-10 Summary 341 Questions 342 Problems 343 Projects and Case Study Problems 344 9 Justification and Applications of Work Cells 345 Chapter Goals and Objectives 345 9-1 Introduction 345 Career Spotlight 346 9-2 Capital Equipment Justification 347 Return on Investment Method, 348 Cash Flow Method, 348 Time Value of Money, 348 Justifying Robotics Applications, 349 Justification Spreadsheet, 349 9-3 Automation Applications 350 Material Handling, 350 Machine Tending, 354 Assembly, 355 Process, 359 Welding, 359 Paint Spraying, 363 9-4 Summary 366 Questions 367 Problems 368 Projects and Case Study Problems 369 10 Safety 370 Chapter Goals and Objectives 370 10-1 Introduction 370 Career Spotlight 371 10-2 Safety Standards 371 Robot Systems and Integrated Work Cells, 372 Contents xxi
Corporate Standards, 372 Governmental and Other Organizations, 372 10-3 Occupational Safety and Health Administration (OSHA) 373 10-4 American National Standards Institute/Robotic Industries Association Standard for Robot Safety 373 10-5 Safeguarding a Work Cell 374 Safeguarding Devices, 374 Safety Hardware, 375 10-6 Presence Sensing Devices 376 Proximity Sensing Devices, 376 Light Curtain Introduction, 378 Light Curtain Operation, 378 Light Curtain Applications, 380 Calculating Safe Curtain Distance, 382 Presence Sensing Mats, 383 Sensing Mat Operation, 383 10-7 Interlock Devices 384 Interlock Switch Operation, 384 Interlock Positive Mode Operation, 385 Forms of Interlock Devices, 385 Power Interlocking, 386 Control Interlocking, 386 Calculating Safe Guard Distance, 386 Mechanical Interlock Devices, 387 Non-contact Interlock Devices, 389 Interlock Switches with Guard Locking, 391 Unconditional Guard Unlocking, 391 Conditional Guard Unlocking, 391 10-8 Safeguarding the Operator 392 10-9 Safeguarding the Programmer 392 10-10 Safeguarding Maintenance and Repair Personnel 392 10-11 Developing a Safety Strategy 393 Risk Assessment, 393 Risk Estimation, 396 Risk Assessment Three Steps, 396 Final Assessment Rating, 398 Hazard Reduction, 399 Personnel Protection Equipment, 400
10-12 Design Guidelines 400 10-13 Safety Justification 401 10-14 Summary 402 Questions 403 Problems 404 Projects and Case Study Problems 405 11 Human Interface: Operator Training, Acceptance, and Problems 407 Chapter Goals and Objectives 407 11-1 Introduction 407 Career Spotlight 408 11-2 General Training 408 General Training Program, 409 11-3 Operator Training 410 11-4 Maintenance Training 410 11-5 Team-based Manufacturing 411 Description of a Self-directed Work Team, 411 Making Work Teams Work, 412 11-6 Resistance 412 11-7 Organized Labor 413 11-8 Impact of 24-7 414 11-9 Summary 415 Questions 416 Projects and Case Study Problems 416 12 Work-Cell Design Case Study 417 Chapter Goals and Objectives 417 Career Spotlight 417 12-1 Introduction 418 12-2 Company Profile 418 12-3 Introduction to CIM Automation at West-Electric 418 West-Electric Automation Team, 419 The First Meeting, 420 12-4 Turbine Blade Production 422 Step 1: Raw Material Inspection, 423 Step 2: Production of Slugs, 424 Contents xxiii
Step 3: Slug Lubrication, 424 Step 4: Extrusion, 424 Step 5: Upset Forging, 425 Step 6: Block Forge, 427 Step 7: Final Forge and Trim, 427 Step 8: Alternate Process for Small Airfoils, 427 Step 9: Deburring, 428 Step 10: Heat-treating, 429 Step 11: Measuring Airfoil Cross-section, 429 Step 12: Chemical Milling, 429 Step 13: Machining Base, 429 Additional Data on the Blade Production Line, 430 12-5 CDM Improvement Process 430 Five-step Design Process, 431 12-6 The Automation Plan 432 12-7 Selection Criteria 435 Work-cell Technical Design Checklist, 436 Robot Selection Checklist, 437 12-8 Performance Measures 440 12-9 Technical Issues 442 Performance Requirements, 442 Layout Requirements, 442 Production Characteristics, 442 Equipment Modifications, 443 Process Modifications, 443 Robot Specifications, 444 Oven Modifications, 446 Work-cell Simulation, 447 12-10 Automation Cell Integration 447 12-11 Work-cell Control 452 12-12 Cell Programming 452 12-13 Cost Justification 455 12-14 Safety Plan 456 Operational Overview, 456 Work-cell Safety, 458 12-15 Final Performance Measures 461 12-16 Case Study Problems 462 Sections 12-1 to 12-4, 462
Sections 12-5 to 12-8, 462 Sections 12-8 to 12-9, 463 Section 12-10, 463 Section 12-11, 464 Section 12-12, 464 Section 12-13, 464 Sections 12-14 to 12-15, 465 Appendix A: Hardware Specifications, 466 Appendix B: Internet Resources, 483 Thomas Register, 484 Web Search Engines, 484 Standard Organizations, 484 Robot Vendors, 484 Automation Sensors, 484 Automation Support Components, 485 Programmable Logic Controllers, 485 Work-cell Control Software, 485 Material Handling Systems, 485 Appendix C: Justification Program, 486 Appendix D: Glossary 491 Index, 503