- •1. TABLE OF CONTENTS
- •2. OVERVIEW
- •3. PROCESS CONTROL
- •3.1 INTRODUCTION
- •3.2 CONTROL SYSTEM CHARACTERISTICS
- •3.3 CONTROLLER TYPES
- •3.4 PROCESS DIAGRAMS AND SYMBOLS
- •3.5 PRACTICE QUESTIONS
- •4. DISCRETE CONTROLLER DESIGN
- •4.1 POSITIONING CONTROLLERS
- •4.1.1 Dead Beat Control
- •4.1.2 Programming Examples
- •4.1.2.1 - BASIC
- •4.1.2.3 - Pascal
- •4.1.2.4 - 6811 Assembler
- •4.1.3 First Order Response
- •4.2 TRACKING
- •4.2.1 Minimum Error
- •4.3 DISTURBANCE RESISTANT
- •4.3.1 Disturbance Minimization
- •4.4 MULTI-CONTROLLER SYSTEMS
- •4.4.1 Disturbance Feedforward
- •4.4.2 Command Feedforward
- •4.4.3 Cascade
- •4.5 SAMPLE TIME
- •4.6 SUMMARY
- •4.7 PRACTICE PROBLEMS
- •5. DISCRETE SYSTEMS
- •5.1 DISCRETE SYSTEM MODELLING WITH EQUATIONS
- •5.1.1 Getting a Discrete Equation
- •5.1.2 First Order System Example
- •5.1.3 Second Order System Example
- •5.1.4 Example of Dead (Delay) Time
- •5.2 DISCRETE CONTROLLERS
- •5.2.1 A Proportional Controller
- •5.2.2 Integral Control
- •5.2.3 Differential Control
- •5.2.4 Proportional, Integral, Derivative (PID) Control
- •5.3 BLOCK DIAGRAMS AND TRANSFER FUNCTIONS
- •5.3.1 The Backward-Shift ‘B’ Operator
- •5.3.2 Reducing Block Diagrams
- •5.3.3 Back-Shift Transform Table
- •5.3.3.1 - A Summary of Differential Equation Solutions
- •5.3.4 Stability
- •5.4 SAMPLING FUNCTIONS
- •5.5 SYSTEM RESPONSE
- •5.6 STEADY STATE ERROR
- •5.7 PRACTICE PROBLEMS
- •6. PETRI NETS
- •6.1 INTRODUCTION
- •6.2 IMPLEMENTATION FOR A PLC
- •6.3 PRACTICE PROBLEMS
- •7. CONTINUOUS CONTROL SYSTEMS
- •7.1 CONTROL SYSTEMS
- •7.1.1 PID Control Systems
- •7.1.2 Analysis of PID Controlled Systems With Laplace Transforms
- •7.1.3 Manipulating Block Diagrams
- •7.1.3.1 - Commercial PID Tuners
- •7.1.4 Finding The System Response To An Input
- •7.1.5 System Response
- •7.1.6 A Motor Control System Example
- •7.1.7 System Error
- •7.1.8 Controller Transfer Functions
- •7.2 ROOT-LOCUS PLOTS
- •7.2.1 Approximate Plotting Techniques
- •7.2.2 State Variable Control Systems
- •7.3 DESIGN OF CONTINUOUS CONTROLLERS
- •7.4 PRACTICE PROBLEMS
- •8. FUZZY LOGIC
- •8.1 COMMERCIAL CONTROLLERS
- •8.2 REFERENCES
- •8.3 PRACTICE PROBLEMS
- •9. MECHATRONICS CIRCUITS
- •9.1 POWER SWITCHING
- •9.2 USER INPUT/OUTPUT
- •9.2.1 Multiplexing
- •10. HARDWARE BASED CONTROLLERS
- •10.1 CIRCUITS
- •10.2 FLUIDICS
- •10.3 PNEUMATICS
- •10.4 PRACTICE PROBLEMS
- •11. EMBEDDED CONTROLLERS
- •11.1 TYPES
- •11.1.1 Micro Controllers
- •11.1.2 DSPs
- •11.1.3 CPUs
- •11.2 CONTROLLER DESIGN EXAMPLE
- •11.3 PRACTICE PROBLEMS
- •12. DISCRETE SENSORS
- •12.1 INTRODUCTION
- •12.2 SENSOR WIRING
- •12.2.1 Switches
- •12.2.2 Transistor Transistor Logic (TTL)
- •12.2.3 Sinking/Sourcing
- •12.2.4 Solid State Relays
- •12.3 CONTACT DETECTION
- •12.3.1 Contact Switches
- •12.3.2 Reed Switches
- •12.4 PROXIMITY DETECTION
- •12.4.1 Optical (Photoelectric) Sensors
- •12.4.2 Capacitive Sensors
- •12.4.3 Inductive Sensors
- •12.4.4 Ultrasonic
- •12.4.5 Hall Effect
- •12.4.6 Fluid Flow
- •12.4.7 Other Types
- •12.5 PRACTICE PROBLEMS
- •13. CONTINUOUS SENSORS
- •13.1 INPUT ISSUES
- •13.2 SENSOR TYPES
- •13.3 ANGULAR POSITION
- •13.3.1 Potentiometers
- •13.3.2 Encoders
- •13.3.3 Resolvers
- •13.3.4 Practice Problems
- •13.4 LINEAR POSITION
- •13.4.1 Potentiometers
- •13.4.2 Linear Variable Differential Transformers (LVDT)
- •13.4.3 Moire Fringes
- •13.4.4 Interferometers
- •13.5 VELOCITY
- •13.5.1 Velocity Pickups
- •13.5.2 Tachometers
- •13.6 ACCELERATION
- •13.6.1 Accelerometers
- •13.7 FORCE/MOMENT
- •13.7.1 Strain Gages
- •13.7.2 Piezoelectric
- •13.8 FLOW RATE
- •13.8.1 Venturi
- •13.9 TEMPERATURE
- •13.9.1 Resistive Temperature Detectors (RTDs)
- •13.9.2 Thermocouples
- •13.9.3 Thermistors
- •13.10 SOUND
- •13.10.1 Microphones
- •13.11 LIGHT INTENSITY
- •13.11.1 Light Dependant Resistors (LDR)
- •13.12 PRESSURE
- •13.12.1 Bourdon Tubes
- •13.13 PRACTICE PROBLEMS
- •13.14 REFERENCES
- •14. ACTUATORS
- •14.1 ACTUATOR TYPES
- •15. DISCRETE ACTUATORS
- •15.1 INTRODUCTION
- •15.1.1 Interfacing
- •15.1.1.1 - Relays
- •15.1.1.2 - Transistors
- •15.1.1.3 - Triacs
- •15.2 TYPES
- •15.2.1 Solenoids
- •15.2.2 Hydraulic
- •15.2.3 Hydraulics
- •15.2.4 Electric
- •15.2.5 Pneumatic
- •15.2.6 Others
- •15.3 PRACTICE PROBLEMS
- •16. CONTINUOUS ACTUATORS
- •16.1 ACTUATOR CONTROL
- •16.1.1 Block Diagrams
- •16.1.2 Linear Control Systems
- •16.1.3 Motor Controllers
- •16.1.3.1 - DC Motors
- •16.1.3.2 - Stepper Motors
- •16.1.3.3 - Separately Excited DC Motor
- •16.1.3.4 - AC Motors
- •16.1.3.4.1 - Synchronous
- •16.1.4 Hydraulic
- •16.2 PRACTICE PROBLEMS
- •17. PROGRAMMABLE LOGIC CONTROLLERS
- •17.1 BASIC PLCs
- •17.1.1 PLC Connections
- •17.1.2 Ladder Logic
- •17.1.3 Ladder Logic Outputs
- •17.1.4 Ladder Logic Inputs
- •17.2 A SIMPLE EXAMPLE
- •17.3 PRACTICE PROBLEMS
- •18. PLC CONNECTION
- •18.1 SWITCHED INPUTS AND OUTPUTS
- •18.1.1 Input Modules
- •18.1.2 Output Modules
- •18.1.2.1 - Relays
- •18.2 PRACTICE PROBLEMS
- •19. PLC OPERATION
- •19.1 PLC ORGANIZATION
- •19.2 PLC STATUS
- •19.3 MEMORY TYPES
- •19.4 SOFTWARE BASED PLCS
- •19.5 PROGRAMMING STANDARDS
- •19.5.2 The Future of Open Architecture Controllers
- •19.6 PRACTICE PROBLEMS
- •20. SWITCHING LOGIC
- •20.1 BOOLEAN ALGEBRA
- •20.2 DISCRETE LOGIC
- •20.2.1 Boolean Algebra for Circuit and Ladder Logic Design
- •20.2.2 Boolean Forms
- •20.3 SIMPLIFYING BOOLEAN EQUATIONS
- •20.3.1 Karnaugh Maps for Combinatorial Design
- •20.4 ADDITIONAL TOPICS
- •20.4.1 Negative Logic
- •20.4.2 Common Logic Forms
- •20.4.2.1 - NAND/NOR Forms
- •20.4.2.2 - Multiplexers
- •20.4.2.3 - Seal-in Circuits
- •20.5 DESIGN CASES
- •20.5.1 Logic Functions
- •20.5.2 Car Safety System
- •20.5.3 Motor Forward/Reverse
- •20.6 PRACTICE PROBLEMS
- •21. NUMBERING
- •21.1 INTRODUCTION
- •21.2 DATA VALUES
- •21.2.1 Binary
- •21.2.2 Boolean Operations
- •21.2.3 Binary Mathematics
- •21.2.4 BCD (Binary Coded Decimal)
- •21.2.5 Number Conversions
- •21.2.6 ASCII (American Standard Code for Information Interchange)
- •21.3 DATA CHARACTERIZATION
- •21.3.1 Parity
- •21.3.2 Gray Code
- •21.3.3 Checksums
- •21.4 PRACTICE PROBLEMS
- •22. EVENT BASED LOGIC
- •22.1 INTRODUCTION
- •22.2 TIMERS, COUNTERS, FLIP-FLOPS, LATCHES
- •22.2.1 Latches
- •22.2.2 Flip-Flops
- •22.2.3 Timers
- •22.2.4 Counters
- •22.3 PROGRAM DESIGN METHODS
- •22.3.1 Process Sequence Bits
- •22.3.2 Timing Diagrams
- •22.4 DESIGN CASES
- •22.4.1 Counters And Timers
- •22.4.2 More Timers And Counters
- •22.4.3 Oscillator
- •22.4.4 More Timers
- •22.4.5 Cascaded Timers
- •22.4.6 Deadman Switch
- •22.4.7 Conveyor
- •22.4.8 Accept/Reject Sorting
- •22.4.9 Shear Press
- •22.4.10 Actuator Failure
- •22.4.11 Palm Button Detection
- •22.5 PRACTICE PROBLEMS
- •23. SEQUENTIAL LOGIC DESIGN
- •23.1 SCRIPTS
- •23.2 FLOW CHARTS
- •23.3 STATE BASED MODELLING
- •23.3.1 State Diagrams Example
- •23.3.1.1 - Block Logic Conversion
- •23.3.1.2 - Single State Equations
- •23.3.1.3 - Entry and Exit State Equations
- •23.3.1.4 - State Transition Equations
- •23.4 PARALLEL PROCESS FLOWCHARTS
- •23.4.1 Implementation with Microcontroller
- •23.5 SEQUENTIAL LOGIC CIRCUITS
- •23.5.1 Latches and Seal-in
- •23.5.2 Shift Registers
- •23.6 PRACTICE PROBLEMS
- •24. ADVANCED LADDER LOGIC FUNCTIONS
- •24.1 ADDRESSING
- •24.1.1 Data Files
- •24.1.1.1 - Inputs and Outputs
- •24.1.1.2 - User Bit Memory
- •24.1.1.3 - Timer Counter Memory
- •24.1.1.4 - PLC Status Bits (for PLC-5s and Micrologix)
- •24.1.1.5 - User Function Control Memory
- •24.1.1.6 - Integer Memory
- •24.1.1.7 - Floating Point Memory
- •24.2 INSTRUCTION TYPES
- •24.2.1 Basic Data Handling
- •24.2.1.1 - Move Functions
- •24.2.1.2 - Mathematical Functions
- •24.2.2 Logical Functions
- •24.2.2.1 - Comparison of Values
- •24.2.2.2 - Binary Functions
- •24.2.3 Boolean Operations
- •24.2.4 Binary Mathematics
- •24.2.5 BCD (Binary Coded Decimal)
- •24.2.6 Advanced Data Handling
- •24.2.6.1 - Multiple Data Value Functions
- •24.2.7 Complex Functions
- •24.2.7.1 - Shift Registers
- •24.2.7.2 - Stacks
- •24.2.7.3 - Sequencers
- •24.2.8 Program Control Structures
- •24.2.8.1 - Branching and Looping
- •24.2.8.2 - Immediate I/O Instructions
- •24.2.8.3 - Fault Detection and Interrupts
- •24.2.9 Block Transfer Functions
- •24.3 DESIGN TECHNIQUES
- •24.3.1 State Diagrams
- •24.4 DESIGN CASES
- •24.4.1 If-Then
- •24.4.2 For-Next
- •24.4.3 Conveyor
- •24.5 FUNCTION REFERENCE
- •24.6 PRACTICE PROBLEMS
- •25. PLC PROGRAMMING
- •25.1 PROGRAMMING STANDARDS
- •25.1.2 The Future of Open Architecture Controllers
- •25.2 PRACTICE PROBLEMS
- •26. STRUCTURED TEXT PROGRAMMING
- •26.1 INTRODUCTION
- •26.2 THE LANGUAGE
- •26.3 PRACTICE PROBLEMS
- •27. INSTRUCTION LIST PROGRAMMING
- •27.1 INTRODUCTION
- •27.2 PRACTICE PROBLEMS
- •28. FUNCTION BLOCK PROGRAMMING
- •28.1 INTRODUCTION
- •28.2 PRACTICE PROBLEMS
- •29. ANALOG INPUTS AND OUTPUTS
- •29.1 ANALOG INPUTS
- •29.1.1 Analog To Digital Conversions
- •29.1.2 Analog Inputs With a PLC
- •29.2 ANALOG OUTPUTS
- •29.2.1 Analog Outputs With A PLC
- •29.3 DESIGN CASES
- •29.3.1 Oven Temperature Control
- •29.3.2 Statistical Process Control (SPC)
- •29.4 PRACTICE PROBLEMS
- •30. CONTINUOUS CONTROL
- •30.1 CONTROLLING CONTINUOUS SYSTEMS
- •30.2 CONTROLLING DISCRETE SYSTEMS
- •30.3 CONTROL SYSTEMS
- •30.3.1 PID Control Systems
- •30.3.1.1 - PID Control With a PLC
- •30.4 DESIGN CASES
- •30.4.1 Temperature Controller
- •30.5 PRACTICE PROBLEMS
- •31. PLC DATA COMMUNICATION
- •31.1 COMPUTER COMMUNICATIONS CATEGORIES
- •31.2 THE HISTORY
- •31.3 WITH PLCs
- •31.4 SERIAL COMMUNICATIONS
- •31.4.1.1 - ASCII Functions
- •31.4.2 ASCII (American Standard Code for Information Interchange)
- •31.5 PARALLEL
- •31.6 NETWORKS
- •31.6.1 Introduction
- •31.6.2 OSI Network Model
- •31.6.2.1 - Physical Layer
- •31.6.2.2 - Data Link Layer
- •31.6.2.3 - Network Layer
- •31.6.2.4 - Transport Layer
- •31.6.2.5 - Session Layer
- •31.6.2.6 - Presentation Layer
- •31.6.2.7 - Application Layer
- •31.6.2.8 - Open Systems
- •31.6.2.9 - Networking Hardware
- •31.7 BUS TYPES
- •31.7.1 Devicenet
- •31.7.2 CANbus
- •31.7.3 Controlnet
- •31.7.4 Profibus
- •31.7.5 Ethernet
- •31.7.6 Proprietary Networks
- •31.7.6.1 - Data Highway
- •31.7.7 Other Network Types
- •31.8 DESIGN CASES
- •31.8.1 PLC Interface To Robots And NC Machines
- •31.9 PRACTICE PROBLEMS
- •32. HUMAN MACHINE INTERFACES (HMI)
- •32.1 INTRODUCTION
- •32.2 HMI/MMI DESIGN
- •32.3 DESIGN CASES
- •32.4 PRACTICE PROBLEMS
- •33. DESIGNING LARGE SYSTEMS
- •33.1 PROGRAMMING
- •33.2 DOCUMENTATION
- •33.3 PLC PROGRAM DESIGN FORMS
- •33.4 PRACTICE PROBLEMS
- •34. IMPLEMENTATION
- •34.1 ELECTRICAL
- •34.1.1 Electrical Wiring Diagrams
- •34.1.1.1 - JIC Wiring Symbols
- •34.1.2 Wiring
- •34.1.3 Shielding and Grounding
- •34.2 SAFETY
- •34.2.1 Troubleshooting
- •34.2.2 Forcing Outputs
- •34.2.3 PLC Environment
- •34.2.3.1 - Enclosures
- •35. PROCESS MODELLING
- •35.1 REFERENCES
- •35.2 PRACTICE PROBLEMS
- •36. SELECTING A PLC
- •36.1 SPECIAL I/O MODULES
- •36.2 PLC PROGRAMMING LANGUAGES
- •36.3 ISSUES
- •36.4 PRACTICE PROBLEMS
- •37. PLC REFERENCES
- •37.1 SUPPLIERS
- •37.2 PROFESSIONAL INTEREST GROUPS
- •37.3 PLC/DISCRETE CONTROL REFERENCES
- •38. USING THE OMRON DEMO PACKAGE
- •38.1 OVERVIEW
- •38.1.1 Installation
- •38.1.2 Basic Use
- •38.1.3 Connecting to the PLC
- •38.2 REFERENCE GUIDE FOR OMRON PLC DEMO SOFTWARE
- •39. INDUSTRIAL ROBOTICS
- •39.1 INTRODUCTION
- •39.1.1 Basic Terms
- •39.1.2 Positioning Concepts
- •39.1.2.1 - Accuracy and Repeatability
- •39.1.2.2 - Control Resolution
- •39.1.2.3 - Payload
- •39.2 ROBOT TYPES
- •39.2.1 Basic Robotic Systems
- •39.2.2 Types of Robots
- •39.2.2.1 - Robotic Arms
- •39.2.2.2 - Autonomous/Mobile Robots
- •39.2.2.2.1 - Automatic Guided Vehicles (AGVs)
- •39.2.3 Commercial Robots
- •39.2.3.1 - Seiko RT 3000 Manipulator
- •39.2.3.2 - DARL Programs
- •39.2.3.2.1 - Language Examples
- •39.2.3.2.2 - Commands Summary
- •39.2.3.3 - Mitsubishi RV-M1 Manipulator
- •39.2.3.4 - Movemaster Programs
- •39.2.3.4.1 - Language Examples
- •39.2.3.4.2 - Command Summary
- •39.2.3.5 - IBM 7535 Manipulator
- •39.2.3.6 - AML Programs
- •39.2.3.7 - ASEA IRB-1000
- •39.2.4 Unimation Puma (360, 550, 560 Series)
- •39.3 ROBOT APPLICATIONS
- •39.3.1 Overview
- •39.3.2 Spray Painting and Finishing
- •39.3.3 Welding
- •39.3.4 Assembly
- •39.3.5 Belt Based Material Transfer
- •39.4 END OF ARM TOOLING (EOAT)
- •39.4.1 EOAT Design
- •39.4.2 Gripper Mechanisms
- •39.4.2.1 - Vacuum grippers
- •39.4.3 Magnetic Grippers
- •39.4.3.1 - Adhesive Grippers
- •39.4.4 Expanding Grippers
- •39.4.5 Other Types Of Grippers
- •39.5 ADVANCED TOPICS
- •39.5.1 Simulation/Off-line Programming
- •39.6 PRACTICE PROBLEMS
- •40. ROBOTIC PATH PLANNING METHODS
- •40.1 INTRODUCTION:
- •40.1.1 ROBOT APPLICATIONS
- •40.1.2 ROBOTIC CONSTRAINTS
- •40.1.3 THE OPTIMIZATION PROBLEM OF PATH PLANNERS
- •40.1.4 EVALUATION OF PATH PLANNERS
- •40.2 GENERAL REQUIREMENTS
- •40.2.1 PROBLEM DIMENSIONALITY
- •40.2.2 2D MOBILITY PROBLEM
- •40.2.2.1 - 2.5D HEIGHT PROBLEM
- •40.2.2.2 - 3D SPACE PROBLEM
- •40.2.3 COLLISION AVOIDANCE
- •40.2.4 MULTILINK
- •40.2.5 ROTATIONS
- •40.2.6 OBSTACLE MOTION PROBLEM
- •40.2.7 ROBOT COORDINATION
- •40.2.8 INTERACTIVE PROGRAMMING
- •40.3 SETUP EVALUATION CRITERIA
- •40.3.1 INFORMATION SOURCE
- •40.3.1.1 - KNOWLEDGE BASED PLANNING (A PRIORI)
- •40.3.1.2 - SENSOR BASED PLANNING (A POSTIERI)
- •40.3.2 WORLD MODELLING
- •40.4 METHOD EVALUATION CRITERIA
- •40.4.1 PATH PLANNING STRATEGIES
- •40.4.1.1 - BASIC PATH PLANNERS (A PRIORI)
- •40.4.1.2 - HYBRID PATH PLANNERS (A PRIORI)
- •40.4.1.3 - TRAJECTORY PATH PLANNING (A POSTIERI)
- •40.4.1.4 - HIERARCHICAL PLANNERS (A PRIORI & A POSTIERI)
- •40.4.1.5 - DYNAMIC PLANNERS (A PRIORI & A POSTIERI)
- •40.4.1.6 - OFF-LINE PROGRAMMING
- •40.4.1.7 - ON-LINE PROGRAMMING
- •40.4.2 PATH PLANNING METHODS
- •40.4.3 OPTIMIZATION TECHNIQUES
- •40.4.3.1 - SPATIAL PLANNING
- •40.4.3.2 - TRANSFORMED SPACE
- •40.4.3.3 - FIELD METHODS
- •40.4.3.4 - NEW AND ADVANCED TOPICS
- •40.4.4 INTERNAL REPRESENTATIONS
- •40.4.5 MINIMIZATION OF PATH COSTS
- •40.4.6 LIMITATIONS IN PATH PLANNING
- •40.4.7 RESULTS FROM PATH PLANNERS
- •40.5 IMPLEMENTATION EVALUATION CRITERIA
- •40.5.1 COMPUTATIONAL TIME
- •40.5.2 TESTING OF PATH PLANNERS
- •40.6 OTHER AREAS OF INTEREST
- •40.6.1 ERRORS
- •40.6.2 RESOLUTION OF ENVIRONMENT REPRESENTAION
- •40.7 COMPARISONS
- •40.8 CONCLUSIONS
- •40.9 APPENDIX A - OPTIMIZATION TECHNIQUES
- •40.9.1 OPTIMIZATION : VELOCITY
- •40.9.2 OPTIMIZATION : GEOMETRICAL
- •40.9.3 OPTIMIZATION : PATH REFINEMENT
- •40.9.4 OPTIMIZATION : MOVING OBSTACLES
- •40.9.5 OPTIMIZATION : SENSOR BASED
- •40.9.6 OPTIMIZATION : ENERGY
- •40.10 APPENDIX B - SPATIAL PLANNING
- •40.10.1 SPATIAL PLANNING : SWEPT VOLUME
- •40.10.2 SPATIAL PLANNING : OPTIMIZATION
- •40.10.3 SPATIAL PLANNING : GENERALIZED CONES
- •40.10.4 SPATIAL PLANNING : FREEWAYS
- •40.10.5 SPATIAL PLANNING : OCT-TREE
- •40.10.6 SPATIAL PLANNING : VORONOI DIAGRAMS
- •40.10.7 SPATIAL PLANNING : GENERAL INTEREST
- •40.10.8 SPATIAL PLANNING - VGRAPHS
- •40.11 APPENDIX C - TRANSFORMED SPACE
- •40.11.1 TRANSFORMED SPACE : CARTESIAN CONFIGURATION SPACE
- •40.11.1.1 - TRANSFORMED SPACE :
- •40.11.2 TRANSFORMED SPACE : JOINT CONFIGURATION SPACE
- •40.11.3 TRANSFORMED SPACE : OCT-TREES
- •40.11.4 TRANSFORMED SPACE : CONSTRAINT SPACE
- •40.11.5 TRANSFORMED SPACE : VISION BASED
- •40.11.6 TRANSFORMED SPACE : GENERAL INTEREST
- •40.12 APPENDIX D - FIELD METHODS
- •40.12.1 SPATIAL PLANNING : STEEPEST DESCENT
- •40.12.2 SPATIAL PLANNING : POTENTIAL FIELD METHOD
- •40.13 APPENDIX E - NEW AND ADVANCED TOPICS
- •40.13.1 ADVANCED TOPICS : DUAL MANIPULATOR COOPERATION
- •40.13.2 ADVANCED TOPICS : A POSTIERI PATH PLANNER
- •40.13.3 NEW TOPICS - SLACK VARIABLES
- •40.14 REFERENCES:
- •41. ROBOTIC MECHANISMS
- •41.1 KINEMATICS
- •41.1.1 Basic Terms
- •41.1.2 Kinematics
- •41.1.2.1 - Geometry Methods for Forward Kinematics
- •41.1.2.2 - Geometry Methods for Inverse Kinematics
- •41.2 MECHANISMS
- •41.3 ACTUATORS
- •41.3.1 Modeling the Robot
- •41.4 PATH PLANNING
- •41.4.1 Slew Motion
- •41.4.1.1 - Joint Interpolated Motion
- •41.4.1.2 - Straight-line motion
- •41.4.2 Computer Control of Robot Paths (Incremental Interpolation)
- •41.5 PRACTICE PROBLEMS
- •42. MOTION PLANNING AND TRAJECTORY CONTROL
- •42.1 TRAJECTORY CONTROL
- •42.1.1 Resolved Rate Motion Control
- •42.1.2 Cartesian Motion System
- •42.1.3 Model Reference Adaptive Control (MRAC)
- •42.1.4 Digital Control System
- •42.2 PATH PLANNING
- •42.2.1 Slew Motion
- •42.2.1.1 - Joint Interpolated Motion
- •42.2.1.2 - Straight-line motion
- •42.3 MOTION CONTROLLERS
- •42.3.1 Computer Control of Robot Paths (Incremental Interpolation)
- •42.4 SPECIAL ISSUES
- •42.4.1 Optimal Motion
- •42.4.2 Singularities
- •42.5 PRACTICE PROBLEMS
- •42.6 MICROBOT OVERVIEW
- •42.7 CRS PLUS ROBOT OVERVIEW
- •42.8 BASIC DEMONSTRATION STEPS
- •43. CNC MACHINES
- •43.1 MACHINE AXES
- •43.2 NUMERICAL CONTROL (NC)
- •43.2.1 NC Tapes
- •43.2.2 Computer Numerical Control (CNC)
- •43.2.3 Direct/Distributed Numerical Control (DNC)
- •43.3 EXAMPLES OF EQUIPMENT
- •43.3.1 EMCO PC Turn 50
- •43.3.2 Light Machines Corp. proLIGHT Mill
- •43.4 PRACTICE PROBLEMS
- •44. CNC PROGRAMMING
- •44.1 G-CODES
- •44.3 PROPRIETARY NC CODES
- •44.4 GRAPHICAL PART PROGRAMMING
- •44.5 NC CUTTER PATHS
- •44.6 NC CONTROLLERS
- •44.7 PRACTICE PROBLEMS
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maximum static torque |
1.1Nm |
39.3 ROBOT APPLICATIONS
39.3.1 Overview
•Unlike many machines, robots are easy to imagine performing tasks, because of their similarity to the human form. This has caused many companies to adopt robots without properly assessing what their strengths and weaknesses are.
•The early days of experimentation lead to many failed applications, as well as some notable successes.
•A useful dichotomy is,
Point-to-Point - A robot that typically only has 2 (or very few) possible positions. These are good for pick and place type operations, and they are often constructed with pneumatic cylinders.
Manipulation - A robot that assembles, or moves parts requires good end of path motion, but does not require as much accuracy in the middle of the path. A higher speed between path endpoints is often desired.
Path Tracking - When arc welding, gluing, etc. the robot must follow a path with high accuracy, and constant speed. This often results in slower motion, and more sophisticated control software.
Operating - The robot will be expected to apply forces to perform work at the end of the tool, such as doing press fits. While the demands for these robots is essentially the same, they must be capable of handling the higher forces required when in working contact with the work.
Telerobotics - Acts as a remote extension of human control, often for safety or miniaturization purposes. In these cases the robots often mimic the human form, and provide some forms of physical feedback.
Services - mail delivery, vacuuming, etc. Biomedical - prosthetic and orthotic devices.
•The number of degrees of freedom of the robot should be matched to the tasks.
•Note: 5 d.o.f. robots will allow the tool to reach all points in space if the tool has an axis of symmetry. For example, a welding torch flame has a symmetrical axis.
•Some commercial applications that have been done with robots are,
-die casting - used for unloading parts from dies, quenching parts, and trimming them with a trim press. The robot may also be used to put inserts into the die.
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-spot welding - spot welding electrodes are clamped in place, and the weld is made. The robot allows many welds to be done.
-arc weldingcontinuous path robots are used to slowly track a path with a continuous rate, and with control of welding parameters.
-investment casting - robots can be used in the pick and place operations involved in making the molds.
-forging- a robot can be used to precisely position the work under the impact hammer, freeing a worker from the handling hot heavy work pieces.
-press workthe robot handles loading parts into the press, and removing the resulting work pieces.
-spray painting- a very popular application in which the robot sweeps the paint head across the surface to deposit a spray. This process has been coupled with electrostatics to improve efficiency and distribution.
-plastic molding - they can be used for loading the hoppers, and unloading the parts. This is most effective when the parts are hard to handle.
-foundry processrobots can be used for ladling materials, and preparation of molds.
-machine toolsrobots can be used for loading and unloading machine tools, and material transfer systems.
-heat treatment process - parts can be loaded into the ovens, unloaded from the ovens, quenched and dried by robots.
-metal deburring - continuous path robots can be used to track rough edges with a compliant tool design.
-palletizing process - parts can be placed in boxes, or on skids in preparation for shipping. Most robots have program commands to support this.
-brick manufacture - a robot can be used for loading and unloading a kiln, and stacking bricks for shipping.
-glass manufacture - a robot can handle the breakable glass with a wide EOAT that prevents sagging, etc. The robot can also be used for grinding edges.
39.3.2 Spray Painting and Finishing
•Air spraying - air under pressure causes the paint to atomize and be propelled to the article to be painted
•Airless spraying - finishing materials, such as paint, are sprayed under considerable hydraulic pressure through a fixed orifice, which causes the paint to be atomized directly without the need for air.
•Electrostatic spraying - Atomized particles (paint or powder droplets) are electrostatically charged. These are attracted to the object being sprayed by the applied electrostatic field. Considerable material savings are achieved since very little of the sprayed material bypasses the object and is lost. Objects being sprayed are kept at a ground potential to achieve a large electrostatic field.
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•Heating of materials - paint decreases in viscosity when heated and can be sprayed with lower pressures. Less solvent is required and there is less overspray of paint. Heating may be used with any of the preceding systems
•Air spraying and electrostatic spraying are the most common methods of application for paints, enamels, powders, and sound absorbing coatings.
39.3.3 Welding
•These tasks are characterized by the need for,
-smooth motion
-conformity to specified paths
-consistent tool speed
39.3.4 Assembly
•General concepts are,
•one or more robots
•each robot may perform a variety of sub-assemblies
•requires a conveyor and inspection station
•A host computer must synchronize robot actions
•A bad part rejection function should be available
•An organized output should be used, e.g. pallets, or shipping crates.
•These tasks are common, but face stiff competition from fixed automation and manual labor.
39.3.5 Belt Based Material Transfer
•When a robot is used in a workcell, the raw part is delivered in, worked on, and then moved out. This can be done using moving belts, etc.
•Parts are placed directly on the belt, or placed on pallets first.
•Belts can travel in straight paths, or in curved paths if flexible belt link designs are used.
•If straight belts are used, transfer points can be used at the end to change part/pallet direction