e-tracking: towards an intelligent wire-edm manufacturing system
TRANSCRIPT
18.06.2014 EPHJ FOF 2014
E-tracking: towards an intelligent wire-EDM
manufacturing system
R. Perez, O. Dixmerias, Ch. Chapatte
GF Machining Solutions
2
• Introduction
• EDM technology
• Latest innovations in Electroerosion Machining: a smart machine
• The Fofdation project
• E-tracking system for wire-EDM: a smart environment
• Conclusions and perspectives
Outline
EPHJ – FOF 2014
Electric Discharge Machining:
What is it?
• No mechanical contact between the
tool and the workpiece
• A controlled discharge is produced
in the gap filled by a dielectric liquid
• The discharge melts and
evaporates the workpiece material:
In die-sinking EDM the
electrode shape is “printed” in the
workpiece
In wire-EDM a profile is cut
along a pre-determined path
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Advances in micro-Wire-EDM
Micro wire EDM machines
• Taper angles 3° / 80mm
• Wire diameter range
0.07 – 0.33 mm
0.02 – 0.05 mm (option)
• Automatic wire changer:
Twin-wire = 2 x 8kg of wire spools
Grain of salt 60 µmWire diameter used in
W-EDM down to 20
µm
Hair section
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Advances in Wire-EDM
Dedicated EDM machines:
• Using integrated axis
• Taper angles >30 degrees
• Wire diameter range
0.07 – 0.33 mm
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• Traverse paths X, Y, Z
220 x 160 x 250 mm
• Work piece dimensions
550 x 330 mm
• Electrode weight 5 kg
• Work piece weight 35 kg
• Generator ISPG 40A
• SF Module standard Ra 0.05 µm
• iQ technology standard for
graphite and copper
FORM 1000Designed for maximal Accuracy and Micro Applications
Advances in micro-die sinking-EDM
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• In process measurement
Repeatability less than 1µm
Accuracy ±1.5 µm
• Application: Machining of teeth of
endoscopic pliers
• Material: Stainless steel
• External diameter : 0.5mm
• Wire diameter: 50 microns
0.5 mm
Integrated Vision Units
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Nano Roughness
Ra = 49 nm
Rz = 460 nm
• Neg. Impuls Length. 60 ns
• Impuls peal 2 Amp
• Discharge frequency 8 MHz
Advances in generator technology
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Quality in surface finishes
• Programmable surface finish for meeting moulding, aerospace and
medical applications as well as manufacturing demands
• May eliminate the need for subsequent polishing
• Real-time monitoring and recording of quality process indicators:
Historical analysis
Data Acquisition
2.5 1.58 1.26 0.5 0.32 0.2 0.03 mm Ra
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Ti-6Al-4V
Quality in surface integrity
Use of MHz range pulsed
discharges eliminates recast
layers and prevents unexpected
fatigue failure of machined parts.
Programming the right spark energy =
respect of surface integrityAfter roughing,
recast layer < 6 µm
Courtesy of Birmingham University
Ti-6Al-4V
After 4 finishing
cuts, recast layer is
not visible
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Micro-applicationsof application Micro EDM
Main sectors
• Medical instruments, implants,
• High precision mould
• Watch making
• Microelectronics
• Micro drilling
• LED applications.
Micro applications
• Micro connectors
• Micro stamping dies
• Micro assembly
• Injection moulding
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Micro-slits Wire / Sinker Erosion
Application
• Die for punching tool
• Electrodes
• Pin arrays
• Direct structuring
Advantages
• Low tool costs
• Transfer: 2D to 3D
• Economic efficiency by replication
• Flexibility and autonomy
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0.20mm
Technical Parameters
Workpiece Carbide
Workpiece height 5 mm
Thread CCA
Thread Ø 0.10 mm
Ra 0.1 mm
Sharp edge tol. +/-1 mm
Main criteria
Profiles with the sharpest
possible edges and best degree
of roughness
Lead frame Fine Cutting
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qmatVw mm3/s
ms
EDM intelligence: The smart machine
Aj
Generator
Process
Control
te, to, …
TECHNO.
Tables
qc
Ref Defect level
Pilot
Expertmin
qlin
Pos
qdot
Motor and mechanics
/ tqrotms
ms
Gap (mm)Ūms
Pilot &
Execution
Software
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qmatVw mm3/s
ms
Process Control Innovations
Aj
Generator
te, to, …
TECHNO.
Tables
qc
Ref Defect
level
Pilot
Expertmin
qlin
Pos
qdot
Motor and mechanics
/ tqrotms
ms
Gap (mm)Ūms
Pilot &
Execution
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Process control Innovations
qmatVw mm3/s
ms
Aj
Generator
Process
Control
te, to, …
TECHNO.
Tables
qc
Ref Defect
level
Pilot
Expertmin
qlin
Pos
qdot
Motor and mechanics
/ tqrotms
ms
Gap (mm)Ūms
Pilot &
Execution
Automatic calculation
of part height in wire
EDM : adjustment of
machining power
Automatic
adjustment of wire
straigthness
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Top-down approach, disparate and
incompatibles IT islands, lack of
interoperability, point solution…
Holistic & bi-directional approach, end-to-end digitization,
convergent and science-based process, interoperable IT
modules, plug-and-produce IT environment, lifecycle
management, sustainability monitoring,… all integrated !
Today, Tomorrow, powered by FOFdation …
FOFDATION: Intelligence beyond
the machine
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I-Innovations at various levelsSmart (open) Machine Controller (SMC) to implement intelligent (What-to-Make process) &
adaptive (closed loop with in-situ verification process) machining towards « first part correct »
Smart Manufacturing Optimizer (SMO) based on unique machine-tool signature
(characterization) to optimize and simulate its kinematic and dynamic performance behaviour
Smart Manufacturing Execution System (SMES): help the manufacturing industry pragmatically
implement the sustainability objectives by extending the scope of (existing) MES to achieve
Energy Efficiency and Sustainability Goals
Smart Enterprise Content Management (SEMC) towards the «production-to-enterprise» asset
integration and overall sustainability management
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Impacts
Strategic impacts for the manufacturing sector
• Reduce machine idle times
• Reduce average machine cycle times
• Increase machine availability
• Improve the manufacturing performance (complexity) and quality
(precision)
• Reduce consumables and waste
• Increase the competivity advantage of European manufacturers in the
global market
Special Focus on supporting SMEs to embrace the knowledge and digital era
Driving (triple) bottom-line with integrated planning
Contribution to relevant standards
European synergy & International cooperation
Product/Process Optimization
SMO
Adaptive & open Controller
SMC
Manufacturing Execution System SMES
Smart &
GreenFactory
Innovation/Knowledge ProductivitySustainability
PLM
ERP
Product/Process Optimization
SMO
Adaptive & open Controller
SMC
Manufacturing Execution System SMES
Smart &
GreenFactory
Innovation/Knowledge ProductivitySustainability
Product/Process Optimization
SMO
Adaptive & open Controller
SMC
Manufacturing Execution System SMES
Smart &
GreenFactory
Innovation/Knowledge ProductivitySustainability
Product/Process Optimization
SMO
Adaptive & open Controller
SMC
Manufacturing Execution System SMES
Product/Process Optimization
SMO
Adaptive & open Controller
SMC
Manufacturing Execution System SMES
Smart &
GreenFactory
Innovation/Knowledge ProductivitySustainabilityInnovation/Knowledge ProductivitySustainability
PLM
ERP
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Application to EDM : eTracking concept & architecture
Concept One platform unique to be installed:
• Connected to the machine: execution activities
• Placed in the office: supervision and management activities
Functionalities to cover:
• Activities Before, during, and after machining
Architecture
Track & Trace level
(SMO)
Mode execution
Workshop supervision
level (SMES)
Mode management
eSupervisioneSupervision
m/c 1 m/c 2
Data
Base
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Optimised path for complex parts with Step-NC inteface
Definition of « reference » (defects, energy consumption),
Simulation
Detect if a part is correct or not and where are located the
problems.
Optimisation
MachiningHistograms, Energy cons.
Compare
Part #1
Check if part is correct
Detect where problems occur
Identify critical factors in part design
Assess energy consumption
Part signature
Reference
DataBase
(History
& Traceability)
A higher level intelligence concept: SMO
3D CAD
model
ClassCad
Step-NC
model
Simulation
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Wire-EDM SMC/SMO architecture
MIP
STEP-NC
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Going higher: the Smart Manufacturing
Execution System
Before machining During machining After machining
Workshop supervision level
Mode management
Track & Trace level
Mode execution
Apply standard
Supervision of on going production
Reaction according:
- Alarms
- Stops of machining
- Materials consumption
- Energy consumption
reporting Define the standard for production
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Before machining: management level
Before machining
Machining reference: criteria and expected real time reaction (alarm – stop)
Checklist:
Procedure for set-up
Maintenance reference: criteria and expected real time reaction (alarm – stop)
Configuration of machine cell
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During machining: management level
During machining
Detailed supervision
Similar than in front of machine
General supervision of activities
Basic status of the entire machine park
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During machining: execution level
During machining
Error machining
detection
Result:
Alarm or stop
According reference machining file
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During machining: execution level
During machining
Risk maintenance
detection
Result:
Alarm or stop
According reference maintenance file
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After machining: management level
After machining
Report analysis:
Results:
Decision for a maintenance task
Decision for a specific control on the part
Final record for traceability
Statistical production analysis
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SMO detail - Part preparation
Selection of process signals to monitor per each power setting.
Power setting
Selection process signals
Reference machining
timeReference wire length
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Definition of references
Definition of process signal references based on previous machining.
The reference is based on selection of a previous machining and
tolerances
Find previous
machining
List of previous
machining for selection
Profile of process signal of selected
machining according to position on path
(with tolerance)
Definition of tolerance to
apply on reference +
actions when tolerances exceeded
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Machining monitoring
Selected process signals are followed up in real time during machining
according to cutting path.
Actions are executed (email, user message, machine suspension) when
tolerances exceeded.
Graphic follow up of machining
position on 2D viewer
Graphic follow up of process signals
according to position on cutting
path
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Part machining report
Machining report : display machining data + in / out of tolerance
Detail of report on process signal
Machining time out of tolerance
Process signal in tolerance
Process signal out of tolerance
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View detail of process signal
• Display process signal data on path with position in / out
tolerance on cutting path
Graphic display (2D viewer) of cutting path
where process signal is in /out of tolerance.
Profile of process signal according to cutting path
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View detail of process signal
• 3D visualiser with out-of-tolerance representation
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Available Monitoring signals
Generator information can be recorded at two levels:
strategy and CNC (position and speed)
Cutting
speed
frequenc
y
Protection
activation
Protection
pause
Servo control parameter
Strategy level on
frequencyStrategy level on
pulse
Overall strategy
level
Activation of protection pause
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Available Monitoring signals
At a second level it is possible to retrieve detailed process information on
the pulse type distribution, which can be used afterwards to elaborate a
part quality identification and discrimination system. Next step: closing
the loop...
0 2 4 6 8 10 12 14 160
20
40
60
80
100
120bleu:TbReel[us], rouge:freq[kHz], magenta:sympa[%], cyan:conta[%], jaune:impat[%], noir:Td[us]
temps[s]
Fic
hie
r sto
p Abnormal increase of short circuits
36 EPHJ – FOF 2014
Conclusions
• EDM technology is an advanced technology with adaptive process
control: a Smart Machine
Advanced strategies and adaptive control for improved precision
and accuracy
Integrated Vision Units for on-machine control
• An new smart environment has been defined by the FOFDATION project
for wire-EDM technology: e-Tracking
A smart machine optimiser (SMO) able to follow up and record
critical process indicators, with respect to a quality reference, and
take action in case of need
A smart manufacturing execution system (SMES) able to define
manufacturing conditions and supervision a machining cell, at
operational and sustainability levels
• The framework for developing an intelligent machine both at process
and interaction levels is defined and offers outstanding possibilities for
improving manufacturing performances by using the full potential of
current digital capabilities.
37 EPHJ – FOF 2014