Advanced Manufacturing Systems Design © 2000 John W. Nazemetz Numerical Control, Robotics, and Programmable Controllers Lecture 7 Topic : Segment A Topic: History and Definitions ADVANCED MANUFACTURING SYSTEMS DESIGN Numerical Control, Robotics and Programmable Controllers History and Definitions Slide 2 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Overview • Numerical Control and Robotics – History – Definitions Slide 3 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics A Brief History (1) • ---Music Boxes, Clocks, Mechanical Toys, etc. (Hard Programming) • 1725 Falcon (France) Used “decks” of punched card/blocks to control looms • 1936 Ford Motor Co. Introduction of “Building Block” Automation Concept • 1941-5 Feedback/Control Mechanisms Developed for Fire Control in US and Briish Navies Slide 4 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics A Brief History (2) • 1947 First Computers Developed • 1947 Parsons Jig/Borer Coupled with Computer (Did Not Function) • 1949 DeVol Develops Recording and Playback Capabilities • 1951 USAF Contract with MIT for NC Development • 1951 JWN born Slide 5 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics A Brief History (3) • 1952 First Parts Cut at MIT on Modified Cincinnati HydroTel • 1952 MIT Demonstrates NC to USAF • 1954 USAF Solicits Proposal for NC Use to Reduce Aircraft Production • 1955 USAF Authorizes NC Equipment Purchases (GFE) • 1956 MIT Develops NC Program for MIT Whirlwind Computer Slide 6 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics A Brief History (4) • 1956 Automatic Programmed Tool (APT) Introduced • 1960 First Commercial Robot Application • 1964 ADAPT (Version of APT) Introduced • Late 1960’s Versions of NC Languages Introduced (COMPACT II, etc.) Slide 7 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics A Brief History (5) • 1970’s Graphical Aids Developed • 1980’s Personal Computer Versions of NC Developed (Computer Assisted Numerical Control Programming) • 1980’s Robotic Applications Spread Slide 8 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Numerical Control – Definitions (1) • Running a Machine Tool By Tape to Make It Produce More for Less (Bendix Industrial Controls NC Handbook) • A System in which Actions are Controlled by The Direct Insertion of Numerical Data at Some Point With At Least Some Portion of the Data Automatically Interpreted (Electronics Industries Association (EIA)) Slide 9 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Numerical Control – Definitions (2) • A Technique for Automatically Controlling Machine Tools, Equipment, or Processes by a Series of Coded Instructions (American Society of Tool and Manufacturing Engineers) • A Technique that Provides Prerecorded Information in a Symbolic Form Representing the Complete Instructions for the Operation of a Machine (Computer aided Manufacturing International (CAM-I)) Slide 10 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Numerical Control – Definitions (3) • A Form of Programmable Automation In Which the Process is Controlled by Numbers, Letter, and Symbols which Form the Program of Instructions for a Particular Workplace or Job (Mikell Groover) Slide 11 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Numerical Control -Advantages for Design • Less Expensive, More Accurate Prototypes • Better Adherence to Specifications • Better Assessment of Production Times/Costs • “Impossible” Parts Can be Made • Integration/Reuse of Computer Models From Design In Manufacturing Slide 12 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Numerical Control -- Advantages for Manufacturing (1) • Greater Flexibility – Shape – Part Volumes • • • • • Increased Accuracy More Operations from a Single Set-Up Less Manufacturing Time Variability Better Scheduling Increased Capacity Slide 13 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Numerical Control -- Advantages for Manufacturing (2) • • • • • • • Greater Machine Utilization Reduced Tooling Costs Reduced Tool Costs Reduced Flow Time Reduced Workpiece Handling Greater Safety Improved Integration Slide 14 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Numerical Control and Robotics • Essentially the Same Thing – Same Basic Technologies • Servo Mechanisms and Feedback for Positioning • NC => Machine Tool Movement (Fixture(Table), Tool, Part) • Robotics => Arm Movement (Fixture (Arm), Tool, Part) – Different Psychology – Solve Different Manufacturing Problems • NC => Technological and Ergonomic Problems • Robotics => Economic and Ergonomic Problems Slide 15 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Robotics -- Definition • A programmable, multi-functional manipulator designed to move materials, parts, tools, or special devices through variable programmed motions for the performance of a variety of tasks -- Robotics Institute of America Slide 16 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Robotics -- Advantages • Cost per Hour – 3 Shifts, Same Capital Investment • Able to Work in Monotonous Jobs • Able to Work In Hazardous Environments • Consistent – Paths – Time – Quality Slide 17 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics -Applicability • Long Series of Operations Where an Error in the Sequence Would Destroy the Value of the Part • Wide Variety of Parts/Sequences on the Same Equipment • Complex Sequences of Operations • Human Operation Impractical Due to Health or Psycho-Motor Requirements Slide 18 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Advanced Manufacturing Systems Design © 2000 John W. Nazemetz Numerical Control, Robotics, and Programmable Controllers Lecture 7 Topic : Segment A Topic: History and Definition END OF SEGMENT Advanced Manufacturing Systems Design © 2000 John W. Nazemetz Numerical Control, Robotics, and Programmable Controllers Lecture 7 Topic : Segment B Topic: Types and Control Numerical Control and Robotics -- Classification • Numerical Control – Type of Control System – Number of Axes/Degrees of Freedom – Type and Number of Tools • Robotics – – – – Slide 21 Type of Control System Degrees of Freedom/Number of Axes Type of Joints Configuration Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics -Basic Types • • • • • • • DNC Open Loop – Direct Numerical Closed Loop Control Incremental – Distributed Absolute Numerical Control Point to Point • CNC Continuous Path – Computer Numerical Control • Adaptive Control Slide 22 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics -- Types • Number of Axes – Numerical Control • 2, 2 ½ , 3, 3 ½ , 4, 4 ½, 5, 6 Axis Machines • Translational and Rotational Axes – Robots • [Arm, Hand] [1,1], [3,0], [3,1], [3,2], [3,3] • Rotational, Linear, Translational • Also – “Named” Configurations Slide 23 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC Axes • Part or Tool Movement – ½ Axis When Axis Movement Limited (Must complete move Before Other Axes Can Move (e.g., Drill – Must Move Up/Down with Table Stopped. Slide 24 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC Axes • Lathe Movement (Top View – 2 Axis) Workpiece Head Turret Tool and Tool Post (Index Rotation) Slide 25 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC Axes • Machining Center Movement (Top View) – Tool or Table Movement (2-6 Axis) – Translation and Rotation Slide 26 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Robot Axes • Joint (Rotational) and Link (Linear) Movement R-R Robot Slide 27 R–R-L Robot Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Robots – Named Configurations • Polar – (RHORIZ, RVERT, Linear) • Cylindrical – (RHORIZ, TranslateVERT, Linear IN/OUT ) • Cartesian – (RHORIZ, TranslateVERT, TranslateIN/OUT ) • Jointed – (RHORIZ, RBASE, RARM ) Slide 28 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Robots – Wrist • Wrist – (Roll, Pitch, and Yaw) Slide 29 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics -Basic Components (1) • Program Prep/Input – GUI and Data Import – Syntax Checking – Graphic Simulation • Machine Control Unit – Signals to Servos – Error Detection Slide 30 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics -Basic Components (2) Servo Mechanisms – “Motion Components” – Electrical, Hydraulic, or Pneumatic • Machine Tool – Executes Programmed Movements, Commands Slide 31 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics -Basic Components (3) • Feedback Unit(s) – “Optional” – Internal to Machine Tool • Position – Monitoring of Process • Temperature • Forces Slide 32 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics -Physical Problems • Inertia – Static (UnderShoot) – Dynamic (OverShoot) – Torque/Speed (Acceleration/Deceleration) • Control/Resolution – Measurement/Causation of Small Movements – Deflection of Components • Error Buildup (Robots) Slide 33 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics -- Physical Components (1) • Movement – Lead Screws/Cylinders – Optical Comparitors/Encoders • Process Sensors – – – – – Slide 34 Accelerometers Temperature Contact Sensors Torque Vibration, etc. Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics -- Physical Components (2) • Process Control – Interlocks – Process Control Programs (Robots) • Part Interfaces – Hands (Robots) • Pneumatic • Magnetic • Fingered – Fixtures (NC) Slide 35 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics -- Physical Components (3) • Prime Movers – Pneumatic (Robotic, NC Tooling and Controls) – Electrical (NC and Robotic) – Hydraulic (Robotic and NC, e.g. Punch) Slide 36 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC -- Physical Control (1) • Components and Control – Stepping Motors – Lead Screws (Rotational to Translational) – Encoders • “Read” Rotations, Portions of Rotation • Can be 200 “pulses/rotation” or more – Gear Lear Screw or Table to Encoder – Potentiometer to Count Revolutions Slide 37 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC -- Physical Control (2) • Components and Control (Resolution Example) – Lead Screws (20 Threads/Inch) – Encoders (200 Pulses/Revolution) – Resolution = 1/20 x1/200 = 1/4000 inch – = .00025 inch Slide 38 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC -- Physical Control (3) • Components and Control (Resolution Example) – Stepping Motor (1.8o per step) – Geared 10:1 – Controllable Step = 1/(200x10) = 1/2000 = .0005 inch – Axes Error is Independent Slide 39 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Robot -- Physical Control • Components and Control (Resolution Example) – Same as NC – Measures Rotation of Joint – Deflection a Problem • Cantilever Loading of Arm • Accumulation of Errors Slide 40 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz NC and Robotics -Programming • “Manual NC Part Programming” – Punch or Key in N, M, G, S, X, Y, Z, T, I, J Commands – These Constitute the “Assembly Language” for NC • “Computer Assisted NC Programming” – Native Language Commands Which are Translated into Assembly Language – GUI Plus Keyboard to Develop Assembly Language Slide 41 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Computer Assisted NC and Robotic Programming INITIALIZATION CAD MODEL MOVEMENT CUTTER LOCATION SYNTAX TOOL CHANGES PART CHANGES POSTPROCESSOR GRAPHICAL VERIFICATION MACHINE TOOL Slide 42 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Command Comparison Type APT COMPACT II VAL Point P1= Point/x,y,z DPT1, x, y, z Lines L1= Line/p1, p2 C1= Circle/p1, r PL1= Plane/p1,p2,p3 S1= Ssurf/Gensur, c1, c2, … Crspl, cc1, cc2, … Abs. Set DLN1, pt1, pt2 HERE p1 SET p1 = POINT (x, y,z) -- DCIR1, pt1, r -- DPLN1, pt1, pt2, pt3 TABCYL, pt1, Slope(30cw), pt2, … -- Abs. Set BASE, x, y, z Abs. Set SET ref = FRAME (p1, p2, p3, p4) Circles Planes Surfaces Origin Slide 43 Computer Integrated Manufacturing Systems -- © 2000 John W. Nazemetz Command Comparison Type APT COMPACT II VAL Tool CUTTER/t1 LOADTL/t1 [,length] ATCHG, tool1, xx GLX, zz GLZ, ss FPM, ff IPR, .rr TLR MTCHG, … SET hand = TOOL (x,y,z, a,b,c) Movement GOLFT/ l1 GORGT/ l1 GOFWD/l1 GOBACK/l1 GODLTA/l1 GOON/l1 GOPAST/l1 GOTO/p1 GOUP/p1 GODOWN/p1 MOVE, pt1 MOVEC, {to} ln1, {to} ln2 DRILL, … BORE, … MILL, … THRD, … CUT, … MOVE, pt1 MOVES, pt1 APPRO, pt1 DEPART, pt1 OPEN OPENI CLOSE CLOSEI Slide 44 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Command Comparison Type APT Variables Sensors (I/O) V1/value -- COMPACT II VAL DVAR1 = value SET V1 = value -SENSOR (n) OUTPUT(-n) Looping ? Label FOR loops GOTO label IF, THEN, ELSE MACROS Miscellaneous COOLNT/ option MACHIN, … GRASP RAPID OFFLNx/xx XS, SPEED FEDRAT/… zz ZL TIMER(t) SPINDL/… ICON, ... WAIT OCON, … Start (Tool) FROM/p1 SETUP, xa, ya, GO, pt1 za HOME Slide 45 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Numerical Control Programming -- Beyond Postprocessors • EIA Standard 494 - “32 Bit Binary CL Exchange Input Format for Numerically Controlled Machine Tool” – Machine Independent – Allows Machine Interchangeability – Possible Because of de facto Standard for NC Assembly Language (CL files) – Not Possible or Likely in Robotics -- No Standard Assembly Language Slide 46 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Advanced Manufacturing Systems Design © 2000 John W. Nazemetz Numerical Control, Robotics, and Programmable Controllers Segment B Topic: Types and Control Lecture 7 Topic : END OF SEGMENT Advanced Manufacturing Systems Design © 2000 John W. Nazemetz Numerical Control, Robotics, and Programmable Controllers Lecture 7 Topic : Programmable Logic Controllers Segment C Topic: ADVANCED MANUFACTURING SYSTEMS DESIGN Numerical Control, Robotics, and Programmable Controllers Programmable Logic Controllers Slide 49 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Overview • Definition • Physical Structure and Components • Programming – Digital Logic – Ladder Logic • Use – Motion Control – Process Control Slide 50 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Programmable Controllers -- Definition • An programmable, industrially hardened microprocessor with extensive, modular I/O capabilities that are electrically isolated from the microprocessor. Volatile memory is usually safeguarded by battery backup. Slide 51 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Programmable Controllers - Physical Structure ACTUATORS PROCESSOR OUTPUT PORTS INPUT PORTS SENSORS MICRO- BATTERY KEYBOARD Slide 52 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Programmable Controllers – Relays/Transistors (1) Normally Open Relay S Control Circuit Energize Control Circuit To Close i N Source Output Circuit Slide 53 Computer Integrated Manufacturing Systems Load © 2000 John W. Nazemetz Programmable Controllers – Relays/Transistors (2) Normally Closed Relay N Control Circuit Energize Control Circuit to Open i S Source Output Circuit Slide 54 Computer Integrated Manufacturing Systems Load © 2000 John W. Nazemetz Programmable Controllers Relay Circuit N LED i S PLC Control Circuit – Module Control (2) LED from PLC closes Relay Circuit (Normally Closed or Open) Which, in turn, Activates Output Circuit i S Source Output Circuit Slide 55 Computer Integrated Manufacturing Systems Load © 2000 John W. Nazemetz Programmable Controllers - Programming Symbols Digital Logic Ladder Logic AND AND INPUT OR OR OUTPUT NOT NOT TIMER Slide 56 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Programmable Controllers - Programming • • • • Define Entities in the System Develop Logical Relationships Set up Digital and/or Ladder Diagrams Use Computer Aided Programming to check Syntax, Simulate Operation Slide 57 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz PLCs - Programming Example Definition • Farmer Jones Problem (1) – Farmer Jones has just been approached for lodging by a Traveling Salesman whose car has broken down. It is 100 miles to the nearest town with a motel. Farmer Jones’ daughter has expressed (positive) interest in the salesman, and his dog, Killer, has also expressed (negative) interest in the salesman. Slide 58 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz PLCs - Programming Example Definition • Farmer Jones Problem (2) – Farmer Jones has a smart house and a smart barn. This allows him to receive a set of signals indicating who is where on the farm (he modified the cow ID tags!). – Develop the digital logic he needs in order to be advised of all potentially undesirable situations. Slide 59 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Programming Example • Farmer Jones Problem (3) – Step 1 – Identify all potentially undesirable situations • Salesman and Killer alone together in either the barn or the house. • Salesman and Daughter alone together in either the barn or the house. Slide 60 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Programming Example • Farmer Jones Problem (4) – Step 2 – Define Input • A high (1) signal will indicate the individual is in the barn. • A low (0) signal will indicate the individual is in the house. Slide 61 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Programming Example • Farmer Jones Problem (5) – Step 3 – Program Salesman/Daughter “Problems” Farmer (1) Killer (1) Salesman (0) Daughter (0) (1) (1) Alarm Salesman (1) Daughter (1) Farmer (0) Killer (0) Slide 62 (1) (1) Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Programming Example • Farmer Jones Problem (6) – Step 4 – Program Salesman/Killer “Problems” Farmer (1) Daughter (1) Salesman (0) Killer (0) (1) (1) Alarm Salesman (1) Killer (1) Farmer (0) Daughter(0) Slide 63 (1) (1) Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Programming Example • Farmer Jones Problem (7) – Step 5 – Program Ladder Logic for Salesman/Killer “Problems” with 30 second delay. Salesman/Daughter Problem (House (0)) F D K S Salesman/Daughter Problem (Barn (1)) F D K S F D K S F D K S Timer 30 sec. Alarm Salesman/Killer Problem (House (0)) Salesman/Killer Problem (Barn (1)) Slide 64 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz PLCs and NC and Robots • All CNCs and Robots Use PLCs • Two Functions – Motion Control – Process Control Slide 65 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Motion Control • Send Pulse Train to Stepping Motors – Control Rotation – Control Speed Slide 66 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Process Control • Input Signal to Controller (On/Off) – Sensors Used to Detect Physical State • Done Continuously – State of Signals Indicates Status • Can be Interrupt Signal (e.g. Alt/Cntr/Del) • Can be Polled (Cyclic Program Review) – Action Taken when Appropriate – Often Done in Background – Latching Circuit (Read like Memory Location) Slide 67 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Motion and Process Control • Within Program, Check Status of Process – Machine Loading • Check Status of Machine Door (Open) Before Robot Moves in to Remove/Load Part • Check Part is in/out of Chuck/Robot Hand Before Moving – Path/Location Control • Check Status of Position Sensors (Within Tolerance/Not) And Activate Correction Subroutine or Next Move Slide 68 Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz Advanced Manufacturing Systems Design © 2000 John W. Nazemetz Lecture 7 Topic : Numerical Control, Robotics, and Programmable Controllers Programmable Logic Controllers Segment C Topic: END OF SEGMENT