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ADVANCED MANUFACTURING SYSTEMS DESIGN Numerical Control, Robotics and Programmable Controllers

Overview

• Numerical Control and Robotics – History – Definitions

NC and Robotics -

A Brief History (1)

• ----

Toys, etc. (Hard Programming)

• 1725

punched card/blocks to control looms

• 1936

“Building Block” Automation Concept

• 1941-5

Music Boxes, Clocks, Mechanical Falcon (France) Used “decks” of Ford Motor Co. Introduction of 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

NC and Robotics -

A Brief History (3)

• 1952

First Parts Cut at MIT on Modified Cincinnati HydroTel

• 1952

MIT Demonstrates NC to USAF

• 1954

to Reduce Aircraft Production

• 1955 • 1956

USAF Solicits Proposal for NC Use USAF Authorizes NC Equipment Purchases (GFE) 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

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

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

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

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

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

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

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

Numerical Control and Robotics - Classification

• Numerical Control – Type of Control System – Number of Axes/Degrees of Freedom – Type and Number of Tools • Robotics – Type of Control System – Degrees of Freedom/Number of Axes – Type of Joints – Configuration

NC and Robotics - Basic Types

• Open Loop • Closed Loop • Incremental • Absolute • Point to Point • Continuous Path • DNC – Direct Numerical

Control

– Distributed

Numerical Control

• CNC – Computer Numerical

Control

• Adaptive Control

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

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.

NC Axes

• Lathe Movement (Top View – 2 Axis)

NC Axes

• Machining Center Movement (Top View) – Tool or Table Movement (2-6 Axis) – Translation and Rotation

Robot Axes

• Joint (Rotational) and Link (Linear)

Robots – Named Configurations

• Polar – (R

HORIZ, R VERT,

• Cylindrical

Linear)

– (R

HORIZ, Translate VERT,

• Cartesian

Linear IN/OUT )

– (R

HORIZ,

• Jointed

Translate VERT, Translate IN/OUT )

– (R

Robots – Wrist

• Wrist – (Roll, Pitch, and Yaw)

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

NC and Robotics - Basic Components (2)

Servo Mechanisms

– “Motion Components” – Electrical, Hydraulic, or Pneumatic • Machine Tool – Executes Programmed Movements,

NC and Robotics - Basic Components (3)

• Feedback Unit(s) – “Optional” – Internal to Machine Tool • Position – Monitoring of Process • Temperature • Forces

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)

NC and Robotics - Physical Components (1)

• Movement – Lead Screws/Cylinders – Optical Comparitors/Encoders • Process Sensors – Accelerometers – Temperature – Contact Sensors – Torque – Vibration, etc.

NC and Robotics - Physical Components (2)

• Process Control – Interlocks – Process Control Programs (Robots) • Part Interfaces – Hands (Robots) • Pneumatic • Magnetic • Fingered – Fixtures (NC)

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)

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

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 –

NC -- Physical Control (3)

• Components and Control (Resolution

Example)

– Stepping Motor (1.8

o per step)

– Geared 10:1 – Controllable Step = 1/(200x10) = 1/2000

= .0005 inch

– Axes Error is Independent

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

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

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

Slide 43

Command Comparison

Type Point Lines Circles Planes Surfaces Origin APT P1= Point/x,y,z COMPACT II DPT1, x, y, z VAL HERE p1 SET p1 = POINT (x, y,z) - 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 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) Computer Integrated Manufacturing Systems © 2000 John W. Nazemetz

Slide 44

Command Comparison

Type Tool Movement APT COMPACT II CUTTER/t1 LOADTL/t1 [,length] ATCHG, tool1, xx GLX, zz GLZ, ss FPM, ff IPR, .rr TLR MTCHG, … 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, … Computer Integrated Manufacturing Systems VAL SET hand = TOOL (x,y,z, a,b,c) MOVE, pt1 MOVES, pt1 APPRO, pt1 DEPART, pt1 OPEN OPENI CLOSE CLOSEI © 2000 John W. Nazemetz

Command Comparison

Type Variables Sensors (I/O) Looping Start (Tool) APT V1/value - ?

Miscellaneous COOLNT/ option RAPID FEDRAT/… SPINDL/… FROM/p1 COMPACT II VAL DVAR1 = value SET V1 = value - Label GOTO label MACROS SENSOR (n) OUTPUT(-n) FOR loops IF, THEN, ELSE MACHIN, … OFFLNx/xx XS, zz ZL ICON, ...

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 Assembly Language Standard for NC Assembly Language (CL files)

– Not Possible or Likely in Robotics -- No

ADVANCED MANUFACTURING SYSTEMS DESIGN Numerical Control, Robotics, and Programmable Controllers

Overview

• Definition • Physical Structure and Components • Programming – Digital Logic – Ladder Logic • Use – Motion Control – Process Control

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.

Programmable Controllers - Physical Structure

Programmable Controllers – Relays/Transistors (1)

Programmable Controllers – Relays/Transistors (2)

Programmable Controllers – Module Control (2)

PLC Control Circuit Relay Circuit N LED i LED from PLC closes Relay Circuit (Normally Closed or Open) Which, in turn, Activates Output Circuit S Slide 55 Source Output Circuit Computer Integrated Manufacturing Systems Load © 2000 John W. Nazemetz

Programmable Controllers - Programming Symbols

Programmable Controllers - Programming

• Define Entities in the System • Develop Logical Relationships • Set up Digital and/or Ladder Diagrams • Use Computer Aided Programming to

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.

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.

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.

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.

Programming Example

• Farmer Jones Problem (5) – Step 3 – Program Salesman/Daughter “Problems”

Programming Example

• Farmer Jones Problem (6) – Step 4 – Program Salesman/Killer “Problems”

Programming Example

• Farmer Jones Problem (7) – Step 5 – Program Ladder Logic for Salesman/Killer

“Problems” with 30 second delay.

Salesman/Daughter Problem (House (0)) Salesman/Daughter Problem (Barn (1)) Salesman/Killer Problem (House (0)) F D K S F D K S F D K S Salesman/Killer Problem (Barn (1)) F D K S Slide 64 Computer Integrated Manufacturing Systems Timer 30 sec.

PLCs and NC and Robots

• All CNCs and Robots Use PLCs • Two Functions – Motion Control – Process Control

Motion Control

• Send Pulse Train to Stepping Motors – Control Rotation – Control Speed

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)

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

Lecture Slides

Transcript Lecture Slides

ADVANCED MANUFACTURING SYSTEMS DESIGN Numerical Control, Robotics and Programmable Controllers

Overview

NC and Robotics -

NC and Robotics -

NC and Robotics -

NC and Robotics -

NC and Robotics -

Numerical Control – Definitions (1)

Numerical Control – Definitions (2)

Numerical Control – Definitions (3)

Numerical Control - Advantages for Design

Numerical Control --

Numerical Control --

Numerical Control and Robotics

Robotics - Definition

Robotics - Advantages

NC and Robotics - Applicability

Numerical Control and Robotics - Classification

NC and Robotics - Basic Types

NC and Robotics -- Types

NC Axes

NC Axes

NC Axes

Robot Axes

Robots – Named Configurations

Robots – Wrist

NC and Robotics - Basic Components (1)

NC and Robotics - Basic Components (2)

NC and Robotics - Basic Components (3)

NC and Robotics - Physical Problems

NC and Robotics - Physical Components (1)

NC and Robotics - Physical Components (2)

NC and Robotics - Physical Components (3)

NC -- Physical Control (1)

NC -- Physical Control (2)

NC -- Physical Control (3)

Robot -- Physical Control

NC and Robotics - Programming

Computer Assisted NC and Robotic Programming

Command Comparison

Command Comparison

Command Comparison

Numerical Control Programming -- Beyond Postprocessors

ADVANCED MANUFACTURING SYSTEMS DESIGN Numerical Control, Robotics, and Programmable Controllers

Overview

Programmable Controllers - Definition

Programmable Controllers - Physical Structure

Programmable Controllers – Relays/Transistors (1)

Programmable Controllers – Relays/Transistors (2)

Programmable Controllers – Module Control (2)

Programmable Controllers - Programming Symbols

Programmable Controllers - Programming

PLCs - Programming Example Definition

PLCs - Programming Example Definition

Programming Example

Programming Example

Programming Example

Programming Example

Programming Example

PLCs and NC and Robots

Motion Control

Process Control

Motion and Process Control

Directory