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An Introduction to Grinding Machine Control Systems John Moruzzi AMTReL An Introduction to Grinding Machine Control Systems Director of Studies: Dr Michael.

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Presentation on theme: "An Introduction to Grinding Machine Control Systems John Moruzzi AMTReL An Introduction to Grinding Machine Control Systems Director of Studies: Dr Michael."— Presentation transcript:

1 An Introduction to Grinding Machine Control Systems John Moruzzi AMTReL An Introduction to Grinding Machine Control Systems Director of Studies: Dr Michael Morgan

2 Personal Introduction John Moruzzi BSc Electrical Engineering & ElectronicsUniversity of Leeds MSC Computational & Statistical Modelling University of Liverpool Known AMTReL since early 90s Software engineeringAerospace / Avionics Manufacturing / Machine Tools OMR / OCR Applications Electrical installationCommercial / Industrial Technical sales / support Grinding machine process control (Balance Systems) An Introduction to Grinding Machine Control Systems

3 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/PhDs Adaptive control (Y Chen) Open CNC Interface (C Statham) High speed Internal grinding Industry co-operations (Timken, Lucas, …) Fluid delivery methods, nozzle design AE monitoring Dressing tool control (fluid coupling)

4 Objectives Machine Re-commission hardware Move axes Replace workhead drive Modifications to wiring Disable hardware limitations Remove original control panel Implement simplified control panel Interface external devices Control system Initial desktop PC control : ISA bus motion control card ISA bus Digital I/O card Standard mouse / keyboard / monitor Initial software Windows 2000 (XP), Visual Basic Programming familiarity Axis configuration Axis movements Simple grinding cycles Simple cycle programming Simple IO features An Introduction to Grinding Machine Control Systems

5 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

6 Axis positioning and control Position measurement Encoder linear scale or rotary 2 quadrature pulsetrains Marker / Zero pulse distance moved and direction Configuration Scaling (pulses / rev, pulses / mm) Thread pitch Limits Axis overtravel switches / signals (+ve, –ve) Axis movement Motion control hardware Position target, move speed Position feedback (speed) Speed reference signal Servo drive Speed reference input (DC +/- 10V) Motor power output (DC / AC) Scaling, Trim, Offsets Servo motor Resolver feedback (speed) Ballscrew An Introduction to Grinding Machine Control Systems

7 Wheelspeed and Workspeed Wheelspeed Rotational speed (RPM)Surface speed (m/sec) Fixed on simple machines, can be changed with gearing / pulleys Variable on more sophisticated machines, can be adjusted for constant speed machining Workspeed Rotational speed (RPM)Surface speed (m/sec) Variable on most grinding machines Controlled by operator / program Open-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

8 Common grinding cycles Dressing Single point diamond dressing: Wheel rotating (surface speed v c ) Wheel traverses past diamond tip (crossfeed velocity v f ) Wheel infeeds an increment (infeed amount a d ) Repeat until wheel surface fully dressed Plunge grinding Workpiece / table positioned relative to wheel Wheel and workpiece rotating (v c and v w ) 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 wheel Wheel and workpiece rotating (v c and v w ) 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

9 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-codes M02End of Program M03Spindle on (CW rotation) M05Spindle Stop M07Coolant on (flood) M09Coolant off G-codes G00Rapid positioning G01Linear interpolation G28Return to home position Canned cycles (J & S Series 10) G86Traverse Grinding G88 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

10 Cycle programming - 2 Plunge cycle Go to Z start pos: Go to X size pos: Go to X start pos: Go to X finefeed pos: Program X coarse feedrate Program X fine feedrate Program Sparkout time Traverse cycle Go to Z right pos: Go to Z left pos: Go to X size pos: Go to X start pos: Go to X finefeed pos: Program X coarse increment Program X fine increment Program sparkout passes 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)

11 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 GaugingDiameter, Shoulder Touch DetectionAE, Power Wheel balancingAuto / Manual Probing An Introduction to Grinding Machine Control Systems Adaptive / Intelligent Control Adaptive strategy Parameter modification Selection strategy Rule / Case based Process models & rules Kinematic, Compliance Database Learning strategy, data

12 Jones & Shipman Ultramat Left-Hand operator panel Manual/ Automatic mode Operation selection – Dress / Plunge / Traverse Program upload / download Linked cycle select Z axis DRO, MPG and scale setting Feedrate Override switch Key enable Cycle interrupt / repeat Traverse hold / dwell Z axis reverse / jog E-stop button Control On button An Introduction to Grinding Machine Control Systems

13 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

14 Machine control comparison An Introduction to Grinding Machine Control Systems J&S Ultramat – Fanuc Processor module Axis / workhead drives IO interfacing modules Ethernet / RS232 / USB J&S 1300X – CT, bespoke 2 x Axis drives 1 x workhead drive IO interfacing with terminal blocks 3-phase / 1 phase transformers

15 Current control hardware – 1300X 4 x Axis encoder inputs X axis, Z axis position X axis, Z axis MPG commands 3 (4) Axis speed control outputs X axis, Z axis speed Workhead (C axis) speed 48 Opto-isolated digital IO 18 inputs (24) 8 outputs (24) RS-232 interface panel display data (out) panel control commands (in) An Introduction to Grinding Machine Control Systems Industrial PC case Motion control card Digital IO card CPU card Power supply

16 Servo Motion control An Introduction to Grinding Machine Control Systems Motion control Kv : Derivative Gain Speed dem = (Pos model –Pos actual ) x Kv Servo Drive Servo Motor Encoder Transmission Speed dem Pos actual Vel actual Vel demand Pos demand

17 Deva 004 : X, Z axis setup Z axis PITCH = -10.0000 MAXVOLT = 3000 (2150) COUNT = 10000.0000MAXSPEED = 60 MAXACCEL = 60 GAIN KV = 15 SPEED = 25 X axis PITCH = -5.0000 MAXVOLT = -3000 (-3850) COUNT = 10000.0000MAXSPEED = 60 GEARING = 1:1.29MAXACCEL = 60 GAIN KV = 45 SPEED = 50 An Introduction to Grinding Machine Control Systems

18 Initial software An Introduction to Grinding Machine Control Systems

19 Process / Cycle parameters Axis X0DatumPosition As Double XHomePosition As Double XZeroPosition As Double XAbsolute As Double Z0DatumPosition As Double ZRevDatumPosition As Double ZHomePosition As Double ZAbsolute As Double An Introduction to Grinding Machine Control Systems Plunge PlungeCoarseInfeed As Double PlungeFineInfeed As Double PlungeFineDia As Double PlungeStartDia As Double PlungeSizeDia As Double PlungeDwell As Double Traverse XCoarseInc As Double XFineInc As Double TraverseZFeed As Double TraverseStartDia As Double TraverseFineDia As Double TraverseSizeDia As Double Z0Dwell As Double ZRevDwell As Double TraversePasses Motion dblXMovespeed As Double dblXRapid As Double dblXCoarseFeed As Double dblXFineFeed As Double dblXInfeed As Double dblXInfeedRate As Double intXDwell as Integer dblXStartPosition As Double dblXFinePosition As Double dblXSizePosition As Double dblZReversePositionL As Double dblZReversePositionR As Double dblZStartPosition As Double intFROSetting As Integer blnFeedHold As Boolean

20 New Components Workhead servo drive Industrial PC Motion control card Touchscreen monitor Console switches / lamps Cabling / connectors An Introduction to Grinding Machine Control Systems

21 Progress So far..... Reactivation of machine tool Minor 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

22 And finally... Thank you..... An Introduction to Grinding Machine Control Systems


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