an introduction to grinding machine control systems john moruzzi amtrel an introduction to grinding...
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An Introduction to Grinding Machine Control Systems
John MoruzziAMTReL
An Introduction to Grinding Machine Control Systems
Director of Studies: Dr Michael Morgan
Personal Introduction
John MoruzziBSc Electrical Engineering & Electronics University of Leeds
MSC Computational & Statistical Modelling University of Liverpool
Known AMTReL since early 90’s
Software engineering Aerospace / AvionicsManufacturing / Machine ToolsOMR / OCR Applications
Electrical installation Commercial / IndustrialTechnical sales / support Grinding machine process
control(Balance Systems)
An Introduction to Grinding Machine Control Systems
AMTReL Jones & Shipman 1300X
• Universal grinding machine• External and Internal wheelheads• SAMM control (Servo Assisted Manual Machine)• Prototype machine based on Format 15 model• Built circa 1994, modified 2001• Closed control system – Industrial PC / MS-DOS
An Introduction to Grinding Machine Control Systems
Used for previous AMTReL projects/PhD’s
Adaptive control (Y Chen)Open CNC Interface (C Statham)
High speed Internal grindingIndustry co-operations (Timken, Lucas, …)Fluid delivery methods, nozzle designAE monitoring Dressing tool control (fluid coupling)
Objectives
MachineRe-commission hardware
Move axesReplace workhead drive
Modifications to wiringDisable hardware limitations
Remove original control panel
Implement simplified control panel
Interface external devices
Control systemInitial “desktop” PC control :
ISA bus motion control cardISA bus Digital I/O cardStandard mouse / keyboard / monitor
Initial softwareWindows 2000 (XP), Visual BasicProgramming familiarityAxis configurationAxis movementsSimple grinding cyclesSimple cycle programmingSimple IO features
An Introduction to Grinding Machine Control Systems
Machine Tool Axes
Cylindrical (Universal) grinding machine
Z axis - horizontal (table)positioning of workpiece for grinding
X axis - radial (wheelfeed / infeed)application of wheel for grinding
C axis - workpiece rotation (workhead)fixed between headstock and tailstock
Surface grinding machine
X axis - horizontal (table)oscillation of workpiece for grinding
Y axis - vertical (“downfeed”)application of wheel for grinding
Z axis - workpiece incremental translation (saddle) clamped to table
An Introduction to Grinding Machine Control Systems
Axis positioning and control
Position measurementEncoder
linear scale or rotary2 quadrature pulsetrainsMarker / Zero pulsedistance moved and direction
ConfigurationScaling (pulses / rev, pulses / mm)Thread pitch
LimitsAxis overtravel switches / signals (+ve, –ve)
Axis movementMotion control hardware
Position target, move speedPosition feedback (speed)Speed reference signal
Servo driveSpeed reference input (DC +/- 10V)Motor power output (DC / AC)Scaling, Trim, Offsets
Servo motorResolver feedback (speed)
Ballscrew
An Introduction to Grinding Machine Control Systems
Wheelspeed and Workspeed
WheelspeedRotational speed (RPM) Surface speed (m/sec)
Fixed on simple machines , can be changed with gearing / pulleysVariable on more sophisticated machines, can be adjusted for “constant speed” machining
WorkspeedRotational speed (RPM) Surface speed (m/sec)
Variable on most grinding machinesControlled by operator / programOpen-loop motor drive control
An Introduction to Grinding Machine Control Systems
N.B. Relationship between wheel speed and workpiece speed crucial to the grinding process
Common grinding cycles
Dressing Single point “diamond” dressing:Wheel rotating (surface speed vc )Wheel traverses past diamond tip (crossfeed velocity vf)
Wheel infeeds an increment (infeed amount ad)Repeat until wheel surface fully dressed
Plunge grinding Workpiece / table positioned relative to wheelWheel and workpiece rotating (vc and vw)Wheel infeed at Rapid speed to start position (dia)Wheel infeed at Coarse feed to Fine Feed start position (dia)Wheel infeed at Fine feed to Final Size position (dia)Sparkout or Dwell with no infeed
Traverse grinding Workpiece / table set to oscillate across wheel to wheelWheel and workpiece rotating (vc and vw)Wheel infeed by Rapid increments to start position (dia)Wheel infeed by Coarse increments to Fine Feed start position (dia)Wheel infeed at Fine feed to Final Size position (dia)Sparkout passes of wheel with no infeed
An Introduction to Grinding Machine Control Systems
Cycle programming - 1
CNC part-programming
Sequence of instruction lines or “blocks”
M-codes functional commands
G-codes movement commands
Canned cycles complex operations(machine specific)
M-codesM02 End of ProgramM03 Spindle on (CW rotation)M05 Spindle StopM07 Coolant on (flood)M09 Coolant off
G-codesG00 Rapid positioning G01 Linear interpolationG28 Return to home position
Canned cycles (J & S Series 10)G86 Traverse GrindingG88 Plunge Grinding
G88 X25.4 Z50.000 D0.50 A0.010 B0.02 C0.0005 P25.5 J25.410 S10 Q0
An Introduction to Grinding Machine Control Systems
Cycle programming - 2
Plunge cycle
Go to Z start pos: <Enter>Go to X size pos: <Enter>Go to X start pos: <Enter> Go to X finefeed pos: <Enter>
Program X coarse feedrate <Enter>Program X fine feedrate <Enter>
Program Sparkout time <Enter>
Traverse cycle
Go to Z right pos: <Enter>Go to Z left pos: <Enter>Go to X size pos: <Enter>Go to X start pos: <Enter> Go to X finefeed pos: <Enter>
Program X coarse increment <Enter>Program X fine increment <Enter>Program sparkout passes <Enter>
Set Z traverse speed
An Introduction to Grinding Machine Control Systems
Guided / Teaching process Manually move to position, save values Enter / adjust values (keypad, buttons)
Architecture of a CNC system
Main Control
Executor Scheduling, program execution, monitoring
IO routines HMI, programming, Digital, Bus
Safety Machine logic
Cycle management Sequencing, monitoring
Motion Control Axis movements, motors
Process optimisation
In-process Gauging Diameter, Shoulder
Touch Detection AE, PowerWheel balancing Auto / ManualProbing
An Introduction to Grinding Machine Control Systems
Adaptive / Intelligent Control
Adaptive strategy Parameter modificationSelection strategy Rule / Case basedProcess models & rules Kinematic, ComplianceDatabase Learning strategy, data
Jones & Shipman Ultramat
Left-Hand operator panelManual/ Automatic modeOperation selection – Dress / Plunge / TraverseProgram upload / downloadLinked cycle select
Z axis DRO, MPG and scale settingFeedrate Override switchKey enable
Cycle interrupt / repeatTraverse hold / dwell
Z axis reverse / jog
E-stop buttonControl On button
An Introduction to Grinding Machine Control Systems
Jones & Shipman Ultramat
Right-hand control panel• X axis DRO, MPG and scale setting• Wheelguard raise, Workhead airlift & unclamp• Gauge apply, Dresser raise • Coolant On/Off, Wheel On/Off, Workhead
On/Off• Cycle Start/Stop
An Introduction to Grinding Machine Control Systems
“Easy” Touch screen• Program / cycle selection• Data entry• Numeric keypad• Navigation• Operator information• Machine setup
Machine control comparison
An Introduction to Grinding Machine Control Systems
J&S Ultramat – Fanuc
Processor moduleAxis / workhead drivesIO interfacing modulesEthernet / RS232 / USB
J&S 1300X – CT, bespoke
2 x Axis drives1 x workhead driveIO interfacing with terminal blocks3-phase / 1 phase transformers
Current control hardware – 1300X
4 x Axis encoder inputsX axis, Z axis positionX axis, Z axis MPG commands
3 (4) Axis speed control outputsX axis, Z axis speedWorkhead (C axis) speed
48 Opto-isolated digital IO18 inputs (24)8 outputs (24)
RS-232 interfacepanel display data (out)panel control commands (in)
An Introduction to Grinding Machine Control Systems
Industrial PC caseMotion control cardDigital IO cardCPU cardPower supply
Servo Motion control
An Introduction to Grinding Machine Control Systems
Motion controlKv : Derivative Gain
Speeddem = (Posmodel –Posactual)x Kv
ServoDrive
Servo Motor
Encoder Transmission
SpeeddemPosactual
VelactualVeldemand
Posdemand
Deva 004 : X, Z axis setup Z axis
PITCH = -10.0000 MAXVOLT = 3000 (2150)COUNT = 10000.0000 MAXSPEED = 60
MAXACCEL = 60GAIN KV = 15
SPEED = 25
X axis
PITCH = -5.0000 MAXVOLT = -3000 (-3850)COUNT = 10000.0000 MAXSPEED = 60GEARING = 1:1.29 MAXACCEL = 60
GAIN KV = 45SPEED = 50
An Introduction to Grinding Machine Control Systems
Initial software
An Introduction to Grinding Machine Control Systems
Process / Cycle parameters
AxisX0DatumPosition As DoubleXHomePosition As DoubleXZeroPosition As DoubleXAbsolute As Double
Z0DatumPosition As DoubleZRevDatumPosition As DoubleZHomePosition As DoubleZAbsolute As Double
An Introduction to Grinding Machine Control Systems
PlungePlungeCoarseInfeed As Double PlungeFineInfeed As DoublePlungeFineDia As DoublePlungeStartDia As DoublePlungeSizeDia As DoublePlungeDwell As Double
TraverseXCoarseInc As DoubleXFineInc As DoubleTraverseZFeed As DoubleTraverseStartDia As DoubleTraverseFineDia As DoubleTraverseSizeDia As DoubleZ0Dwell As DoubleZRevDwell As DoubleTraversePasses
MotiondblXMovespeed As Double dblXRapid As Double dblXCoarseFeed As DoubledblXFineFeed As DoubledblXInfeed As DoubledblXInfeedRate As DoubleintXDwell as Integer
dblXStartPosition As DoubledblXFinePosition As DoubledblXSizePosition As Double
dblZReversePositionL As DoubledblZReversePositionR As DoubledblZStartPosition As Double
intFROSetting As IntegerblnFeedHold As Boolean
New Components
• Workhead servo drive• Industrial PC • Motion control card• Touchscreen monitor• Console switches / lamps• Cabling / connectors
An Introduction to Grinding Machine Control Systems
Progress
So far.....
Reactivation of machine toolMinor electrical modifications
Development software with “old” hardware
Familiarity with motion control package
Implementation of simple cycles
Axis configuration and movement
Specification and ordering of equipment
Initial interface design
Next steps....
Commissioning of workhead drive
Axis movement via MPGs: Incremental Rapid
Digital IO Equipment control
Axis limits etc.
PCI motion card Cabling
Control panel
Initial demonstration software
An Introduction to Grinding Machine Control Systems
And finally...
Thank you.....
An Introduction to Grinding Machine Control Systems