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

3 EPHJ – FOF 2014

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

4 EPHJ – FOF 2014

Advances in Wire-EDM

Dedicated EDM machines:

• Using integrated axis

• Taper angles >30 degrees

• Wire diameter range

0.07 – 0.33 mm

5 EPHJ – FOF 2014

• 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

6 EPHJ – FOF 2014

• 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

7 EPHJ – FOF 2014

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

8 EPHJ – FOF 2014

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

9 EPHJ – FOF 2014

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

10 EPHJ – FOF 2014

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

11 EPHJ – FOF 2014

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

12 EPHJ – FOF 2014

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

13 EPHJ – FOF 2014

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

14 EPHJ – FOF 2014

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

15 EPHJ – FOF 2014

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

16 EPHJ – FOF 2014

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

17 EPHJ – FOF 2014

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

18 EPHJ – FOF 2014

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

19 EPHJ – FOF 2014

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

20 EPHJ – FOF 2014

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

21 EPHJ – FOF 2014

Wire-EDM SMC/SMO architecture

MIP

STEP-NC

22 EPHJ – FOF 2014

-23-

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

23 EPHJ – FOF 2014

-24-

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

24 EPHJ – FOF 2014

-25-

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

25 EPHJ – FOF 2014

-26-

During machining: execution level

During machining

Error machining

detection

Result:

Alarm or stop

According reference machining file

26 EPHJ – FOF 2014

-27-

During machining: execution level

During machining

Risk maintenance

detection

Result:

Alarm or stop

According reference maintenance file

27 EPHJ – FOF 2014

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

28 EPHJ – FOF 2014

-29-

SMO detail - Part preparation

Selection of process signals to monitor per each power setting.

Power setting

Selection process signals

Reference machining

timeReference wire length

29 EPHJ – FOF 2014

-30-

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

30 EPHJ – FOF 2014

-31-

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

31 EPHJ – FOF 2014

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

32 EPHJ – FOF 2014

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

33 EPHJ – FOF 2014

View detail of process signal

• 3D visualiser with out-of-tolerance representation

34 EPHJ – FOF 2014

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

35 EPHJ – FOF 2014

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