Transcript Numerical Control

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