misc controlsc control

FASCINATION OF SHEET METAL

A material of l imitless possibil it ies

This work is protected by copyright. All rights reserved, including the right

to translate, reprint, or reproduce this book or any part thereof. No part

of this publication may be reproduced, stored in a retrieval system, or

transmitted in any form or by any means whatsoever, whether electronic,

mechanical, photocopying, recording, or otherwise, without the prior

written permission of the publisher.

While great care has been taken to ensure the accuracy of the contents

of this book, the author, the editor and the publisher do not assume any

liability for damages, direct or indirect, arising from the use of this book,

in part or total, except where prohibited by law.

ABOUT THIS PUBLICATION

Editor Dr. Nicola Leibinger-Kammüller, TRUMPF GmbH + Co. KG, Ditzingen, Germany

Author Gabriela Buchfink

Translation Matthew R. Coleman

Project coordinators Frank Neidhart, Gabriela Buchfink

Project associates Dr. Nicola Leibinger-Kammüller, Dr. Klaus Parey, Ingo Schnaitmann

Layout and design Felix Schramm, Karen Neumeister (SANSHINE GmbH, Stuttgart)

Text consultant Gurmeet Röcker

Translation coordination euroscript Deutschland GmbH, Berlin

Production coordination Jeanette Blaum (SANSHINE GmbH, Stuttgart)

Printing Rösler Druck GmbH, Schorndorf

Finishing Oskar Imberger & Söhne GmbH, Stuttgart

Binding Josef Spinner Großbuchbinderei GmbH, Ottersweier

Image editing Reprotechnik Herzog GmbH, Stuttgart

Publisher Vogel Buchverlag, Würzburg

ISBN-13 978-3-8343-3071-0

ISBN-10 3-8343-3071-X

1st edition 2006

THE CONTROL: THE BRAINS OF A MACHINE

THE CONTROL: THE BRAINS OF A MACHINE

194 195

196 | A BRIEF HISTORY OF CONTROL TECHNOLOGY

Many faces and tasks

Punched tape instead of templates

CNC and PLC

A growing number of components

Wait, it gets more complicated

204 | IN DIALOG WITH THE MACHINE

The human interface

Touchscreen instead of pushbuttons

Intuitive operation of complex machines

Diagnostics

208 | MAKING THE CONNECTION

Part of the IT infrastructure

Text messages from the machine

Remote diagnostics

212 | TECHNOLOGICAL WHIZ KIDS

MACHINES THAT PERFORM THOUSANDS

OF PUNCH OPERATIONS A MINUTE, MOVE

THE LASER CUTTING HEAD AT L IGHTNING

SPEED, COORDINATE ROBOTS, AND SEND

TEXT MESSAGES TO NOTIFY PEOPLE OF

THE MACHINE STATUS – THIS IS SHEET

METAL FABRICATION TODAY. NONE OF

IT WOULD BE POSSIBLE WITHOUT THE

CONTROL AND THE RAPID ADVANCES

THAT CONTROL TECHNOLOGY HAS MADE

IN RECENT YEARS.

A brief history of control technology

MANY FACES AND TASKS

Project managers aren’t the only ones who have to think about

a thousand different things at once, while still completing work

packages, delegating them to others, checking the results,

and sticking to deadlines.

For the machine control, each production job is a highly

complex project, starting with the NC program, which pro-

vides the instructions, and ending with the finished parts,

properly sorted and arranged in boxes. Getting from start to

finish involves hundreds of thousands of individual signals,

processes, and mathematical operations. And who does it

all? Who coordinates everything? You got it: the control.

One word, many meanings | “Control” means different

things to different people. Control developers use the term

to refer to all technical components and programs in the

machine responsible for running the NC program.

For operators, the interior of the machine is usually noth-

ing more than a black box. They are unaware of the exact

processes involved in operations like moving the punching

head at 1,200 to 2,800 strokes per minute. When operators

say “control,” they mean an instrument used to operate the

machine. The interfaces used today include the touchscreen,

keyboard, mouse, and operating software, providing intuitive

access to the complex processes inside the machine.

Finally, the machine is connected via an interface to the

company’s IT network, enabling continuous data flow be-

tween the office computer and the machine both within the

company and beyond. First-generation NC and the highly

complex systems of today are worlds apart. If you were to go

back in time to the 1950s and tell an operator about a future

where machine manufacturers are able to correct machine

errors online, the operator would probably just shake his head

in incomprehension. Today, this technology is a reality.

The control has different components for operating the machine, enabling automatic production, and for exchanging data.

The brains of the machine Without a control system, the machine is

like a car without a driver: everything is fully functional, but there’s no

one to guide the machine, tell it what to do, coordinate the numerous

processes, trigger an action, or even start the motor. In this sense, the

control is truly the “brains” of the machine.

PUNCHED TAPE INSTEAD OF TEMPLATES

In the 1950s, people were still operating sheet metal working

machines manually. They would position the workpiece and

then flip a switch or press a button to make the machine

work. On a copy punch, operations were carried out in a sim-

ilar fashion. To fabricate a part in large quantities, you first

had to create an initial part using conventional means. The

part was then used as a template for batch production of

further parts.

The template was attached to the side of the work table.

Then the sheet to be processed was placed on the table

and clamped. To position the workpiece correctly under

the punching head, the operator used a stylus to trace the

contour of the template. As the operator guided the stylus,

the work table moved to the corresponding position. After

the sheet was in position, the operator pressed a button to

punch the sheet.

Each of these operations incorporates the typical ele-

ments of a control process:

• Input signal | A button is pressed to trigger the punch-

ing operation.

• Output | The control passes the signal on to the corres-

ponding actuator – in this case, the motor, which then

lowers the punch.

• Actuators | The actuators in the machine receive

and implement the output signal. Actuators can be

mechanisms like motors or valves. As soon as an actua-

tor receives a signal, it performs a specific operation,

e.g. motors start up and valves open or close.

• Result | The punching head is lowered. The workpiece

is punched through.

1 A copy punch still required a certain degree of manual work.

2 Punched tape served as the first storage medium for control programs.

1

2

196 | The control: the brains of a machine 197

NC controls enable automated production.

In a manual production approach, the quality of the fabricated

part fluctuates according to the experience, expertise, and

motivation of the operator. Each human movement is slightly

different from the one preceding it. This, in turn, makes it

nearly impossible to fabricate multiple identical parts. Time is

an additional factor; it is not possible to speed up the work

process to any great degree.

First-generation NC controls | As early as the 1950s,

people were working to develop machines that would be able

to perform operations automatically, enabling fabrication of

identical parts and speeding up the work process.

First, two questions had to be answered:

• How should the instructions be written so that a

technical device will understand them?

• What sort of device should be used to interpret

and carry out the instructions?

NC technology was the solution. NC, or numerical control, uses

numerical commands to control the machine. The motion and

switching information is contained in the NC program as sets

of encoded instructions consisting of numbers, letters, and

special characters. On early machines, punched tape served

as the storage medium. The NC program was coded as a

pattern of holes that were punched onto long rolls of paper

tape. An NC system was able to read, interpret, and pro-

cess the NC program. The first NC systems were produced

by Bendix (USA) and Siemens (Germany).

The NC controls were able to execute only certain NC

commands which, in Germany, were defined in the DIN 66025

standard. If machine tool builders wanted to use specific NC

commands, they had to discuss the changes with the control

manufacturers and have the control adapted.

Putting it into perspective To store an NC program for a punch press

today, you would need a roll of paper tape around two kilometers long.

NC programs like these are typically just under one megabyte. In an age

where storage capacity is measured in gigabytes and online data ex-

change is routine, the size of the NC program is hardly worth mentioning.

The first NC code NC, or numerical control, uses numerical commands

to control the machine. The first NC code was defined in the 1972

German DIN 66025 standard along with commands for path and switch-

ing functions. G02, for instance, describes a circular, clockwise motion;

M25 activates a punching stroke.

1 Punch press with NC: the switch cabinet is behind the machine.

1

Switching | In addition to the NC, a mechanical element

was needed to coordinate the switching functions. This

meant not only triggering a switching function, but also

checking whether all the conditions for a particular function

had been satisfied.

For the switching logic, control engineers back then used

electromechanical components, or, more specifically, relays.

Large switch cabinets filled from top to bottom with hundreds

of relays and a maze of wires were an attestation to the com-

plexity of the switching logic. Indeed, finding the source of

an error in such cabinets was tantamount to looking for the

proverbial needle in a haystack.

CNC AND PLC

In the 1970s, a new generation of controls appeared: CNC, or

computerized numerical control. As the name implies, CNC

relies on the use of program-controlled electronic computers

to control the machine tools.

CNC systems comprise the following components:

• Microprocessor with memory for processing

and storing data

• Operating software for coordinating and

communicating operations

These are the same elements that you find in personal com-

puters, cellular phones, or personal digital assistants.

Effects | The advantage of this hardware design is easy to

see. On earlier NC machines, the arithmetic logic consisted of

electromechanical elements and, for this reason, had to be de-

veloped individually for each type of machine and fabrication

technology. The electronic computers of CNC systems, on

the other hand, were able to calculate anything coming from

the program. This meant that the developers only had to

adapt the programs to the machine and technology.

This development represented a quantum leap in mecha-

nical engineering. Higher computing speeds enabled higher

machine speeds and greater positioning accuracy. CNC also

cleared the way for the development of processing techniques

such as laser cutting and laser welding.

Open control | Despite these advances, machine tool

builders were still unable to integrate their technological

knowledge into the CNC operating software by adding their

own NC commands. As with NC systems, they were still de-

pendent on the control manufacturers.

This didn’t change until 1993, when open controls were

introduced. Standardized open interfaces allowed machine

tool builders to integrate their technical know-how and ma-

chine expertise directly into the operating software.


The evolution of the switch cabinet | Microprocessor

technology not only altered the technical components of the

NC control, but also those of the switch cabinet. At the 1970

World Expo in Chicago, visitors marveled at the first micro-

1 Control technology in the computer age: mechanical and electro-

mechanical components have given way to electronic circuit boards.

“A cell phone today can do more than any of the early NC systems.

In the last 20 years, computing power has increased more than a

thousand fold – that’s not a development, that’s an explosion.”

Rainer Hofmann, System Development

processor with operating software capable of replicating the

logic of a relay switch. This spelled the end of the era of giant

switch cabinets, and the PLC, or programmable logic con-

troller, was born.

Although the hardware may have changed in the course

of time, the job itself remains much the same. Like earlier

systems, the PLC controls the machine functions by pro-

cessing input signals and passing on output signals to the

actuators of the machine. The link between the input and

output is stored in the PLC software.

For many years, control developers relied on special pro-

gramming methods such as Function Block Diagram, Ladder

Diagram, or Instruction List to program the logic operations

in the control program. Since the 1990s, control software

programmers have been able to use high-level programming

languages like Structured Text and the standardized pro-

gramming language C for this.

1Components and mode of operation of a CNC-controlled machine

Fieldbus A fieldbus is a network system connecting the individual con-

trol units. The fieldbus shuttles data packets back and forth, enabling

communication between different control units. Each data packet has a

destination address. The control units check the packets as they pass by.

When they find a packet addressed to them, they take it and process it.

A GROWING NUMBER OF COMPONENTS

Today, the CNC still forms the core of all machine control

systems. Computers have become so much a part of our

daily lives that people have even reverted to using the old

term “NC”. The NC still reads the program and calculates

all geometric, or path, data. Information on switch functions

such as activating a punching stroke is relayed to the PLC.

The NC today is a powerful computer, and the PLC is of-

ten a circuit board built into the computer like a network card

in a personal computer. More recently, though, the classic

distinction between NC and PLC tasks has become blurred.

This is due to the speed of the NC, which operates much

faster than the PLC, and the fact that machine manufactur-

ers are now able to expand the NC functionality on their own.

Because of the NC’s high speed, it makes more sense to

shift the extremely fast switching functions to the NC. In one

instance, machine manufacturers have been able to adopt

this approach for special laser cutting processes requiring

lightning-fast activation and deactivation of the laser beam.

WAIT, IT GETS MORE COMPLICATED

Today, machine control systems are no longer composed ex-

clusively of an NC and PLC. Other devices are also involved:

sensors, automation components such as robots, and even

mechanical elements like the punching head each have their

own control consisting of a processing unit and operating

software. All of these elements are linked together via a field-

bus control network.

Control technology today: CNC and PLC still form the core of the control, but are now connected to additional control units via a network.



Integrated intelligence Machine control technology today resembles

a network of small, interlinked brains, each of which is specialized to

perform a particular task. The NC is the main control that watches over

everything.

The main control is still the NC. It reads the NC program and

delegates tasks to the appropriate control unit. With several

different control units working in parallel, the total processing

power of the machine control has increased considerably.

For the machine to be able to function as a whole, it has to

be very clear which control unit is supposed to implement

the signal and when. In this arrangement, measured values

are always given priority over programmed settings.

Here’s an example. During laser cutting, the distance be-

tween the cutting nozzle and workpiece has to remain constant

to ensure uniform cutting results. This distance is programmed.

At the start of the machining operation, the cutting head

moves to the appropriate position and, initially, stays at this

height. During the cutting process, a sensor measures the

actual distance between the cutting nozzle and the work-

piece. If the distance changes, the sensor control calculates

a new value to compensate for the difference and sends a

signal to the motors responsible for positioning the cutting

head. The signal is immediately implemented.

Another example is the “feed hold” button, which is designed

for use if a malfunction occurs during production. When ac-

tivated, it stops the machine in its tracks. Any motions or

operations already in progress are halted immediately. For this

to work, the “feed hold” button has to be given top priority.

The advent of NC technology brought about changes in

equipment that were easy to see. Current advances, however,

are more subtle, often hidden away deep inside the machine.

To see the effect of improved features, you have to look at

the data tables of the manufacturers and the higher produc-

tivity achieved by the users.

What this means for the operator | While the complex-

ity of the machine continues to increase, the cognitive skills

of the people operating it remain the same. The following

factors can be problematic for human operators:

• Quantity of information | Large amounts of infor-

mation have to be processed.

• Interconnected information | Different kinds of

information are interlinked.

• Lack of system transparency | The structure and

operation of the system are not understood.

• Nonlinear processes | Processes are not carried

out in sequence, but, instead, occur simultaneously.

These factors are typical of machine control processes. Yet

how can machine operation be made easier or even entirely

intuitive? The answer is the operating software. As the inter-

face between operator and machine, it reduces data volume,

creates clear structures, makes processes and dependencies

more transparent, and simulates work sequences.

1

1 The laser cutting head has its own control, which, among other things,

ensures a constant distance between the nozzle and workpiece.

KEEPING THE USER AT THE CENTER OF IT ALL

At home, only one person knows how to program the VCR,

even though it’s supposed to be so easy that anyone can do

it. Sound familiar? Machine processes are a great deal more

complex, and they are controlled using sophisticated operat-

ing software. Is it possible to design a software that is simple

enough to be used intuitively?

“Yes, it is,” says Klaus Bauer, head of the development

team for user interfaces and software at TRUMPF Werkzeug-

maschinen GmbH + Co. KG in Ditzingen, Germany. “To do this,

you have to involve the user in the development process from

the very start.” The team has developed a completely new

type of control software, relying on methods and approaches

used in designing user-centered software.

The operator, service technician, programmer, and the pro-

duction manager are all people who interact with the machine

on a daily basis. Developers worked closely with all of them

to design the software, beginning with a context analysis.

“We defined user groups, described their requisite skills and

characteristics, and made a note of all activities and the typi-

cal work sequences. In addition, we took into account the

work environment: the lighting, dirt, noise, time pressure – all

of these factors characterize the work on the machine,” ex-

plains Klaus Bauer.

Next, the team set to work developing the screen design,

program sequences, and dialog boxes of the software. The

overall concept was elaborated in numerous workshops.

Throughout this process, the developers never lost sight of

the user. A usability test was conducted to see whether the

concept would work. Machine operators used a prototype of What to do when the operator starts pressing the touchscreen with his

work gloves on: usability tests can help to find the answer.

the software to perform realistic tasks. They tested sequenc-

es, the graphical design of the software, and the hardware.

“One of the operators went straight up to the touchscreen and

started pressing it with his dirty work gloves on,” recalls Klaus

Bauer. Now the touchscreen is covered with a replaceable

protective film. After the usability test, details were defined

of the software and program in the final version.

As the first machines began working with the new soft-

ware, the team was encouraged by the results. “The new

software makes machine operation easier. This has a positive

effect on its acceptance as a whole,” says Klaus Bauer. Since

then, the approach has proved successful in other projects.

A handbook documents the results of the first project. The

smooth implementation makes up for the longer time spent

on usability tests and workshops. Overall development time

has dropped considerably compared to previous projects.

205

In dialog with the machine

1

2

THE HUMAN INTERFACE

As automated as machines have become, humans are still

the ones who load the program, set up the machine, and start

it. Humans also monitor the production process, stepping in

if a malfunction occurs.

Ergonomics, or Human Factors, is a scientific discipline

that examines the interaction between humans and machines.

More specifically, HCI, or human-computer interaction, con-

cerns the interaction between humans and computers.

Machines that can be operated quickly and safely have a di-

rect impact on productivity by reducing downtimes. For this

reason, an effort is made to create user interfaces that can

be used intuitively, thereby minimizing the need for lengthy

operator training. Machine manufacturers today are work-

ing to develop standardized software interfaces that function

according to the same principles, regardless of the machine

or technology involved.

TOUCHSCREEN INSTEAD OF PUSHBUTTONS

Early human-machine interfaces involved the use of hand

wheels, pushbuttons, and flashing lights. The development

of NC and, later, CNC, resulted in a dramatic increase in the

number of machine functions and, thus, the number of buttons.

After an additional graphical display screen was integrated

“The control panels of CNC systems at the end of the 1970s had count-

less buttons and switches. To control the machine, the operator had to

find his way around a sea of buttons. Today, controlling a machine can be

compared to using PC software. For developers, each process running

in the background is a great challenge – that no one ever sees.”

Klaus Bauer, HCI System Development

1 Control panel from the 1950s

2 In the 1970s, graphical displays simplify interaction.

3 Control panels with softkeys reduce the number of buttons.

3

into the control panel, it became possible for the first time to

display all information about the part, NC program, technology

data, and operations directly at the machine.

Softkeys | The next generation of control panels incorpo-

rated softkeys to reduce the number of buttons and simplify

use of the operating software. Softkeys are multipurpose

buttons located under, or on the side of, the screen. The

function of the buttons is displayed on the screen and can

change. The functions always relate to the task currently

being carried out by the operator.

A computer, too | In the mid-1990s, as open controls

began appearing, personal computers started making their

way into the design of the user interface. The development

was not unlike the move from DOS to Windows: machine

tool builders now developed graphical user interfaces that

had simulated buttons, which were used either in addition to,

or instead of, the softkeys. Today, the human-machine inter-

face looks almost exactly like a regular computer workstation

with screen, keyboard, and mouse. Windows or Linux serves

as the operating system, and all operations are carried out

using the operating software.

Look a little closer, though, and you’ll find some differ-

ences. The operating software is tailored precisely to the

machine, and the screen is a touchscreen that responds to

the operator’s touch. In addition, there are special switches

and buttons such as the “feed hold” button for direct acti-

vation of certain machine functions. On press brakes, you

can also find an operating station with a foot or hand switch

for activating the bending operation. The operating software,

control panel, and operating station are tailored for each

other and have a user-friendly design.

204 | The control: the brains of a machine

206 | The control: the brains of a machine

1 Operator interface of a press brake

2 The user interface of a laser cutting machine

3 Diagnostics: the control identifies the cause and

suggests a course of action.

INTUITIVE OPERATION OF COMPLEX MACHINES

Operators today control all of the machine functions with the

help of software. Even if you want to move a machine axis

manually, you still have to select and activate the axis in the

operating software. After this is done, the axis can be moved

with a switch.

In defining the functions and sequences, machine manu-

facturers take into consideration the work an operator has

to perform. To see how this works, let’s take a look at the

operating software of a press brake.

The software design | The operator’s main activities, such

as part production, are arranged vertically on the right side

of the screen. Tabs appear on the screen when an activity is

selected by the operator. The tabs show the activities that

the operator has to complete in order to prepare the machine

for production. These activities include entering the data

needed for the fabrication process. A separate tab is pro-

vided for each activity.

Each tab contains text boxes and lists allowing the user

to select various items. In addition, there are detailed views

of the part or machine. At the bottom of the screen, there

is a row of buttons for performing specific actions such as

loading an NC program. At the top left of the screen, there

are symbols showing the machine status as well as any

errors or warnings. A green symbol, for example, shows that

the machine is ready for operation.

Multilevel interaction | In addition to the design, the

methods of data entry are important factors determining

whether the program will be fast, intuitive, and easy to use.

Today, a combination of touchscreen, keyboard, and mouse

is generally used.

The most important tool for entering data is the touch-

screen. The graphical interface of the software is designed so

that the operator can select any function by simply touching

the screen. People who prefer this approach point out that

the touchscreen makes interaction between humans and the

software more direct. The mouse is used for detailed naviga-

tion tasks such as selecting parts within the sheet graphic.

Wizards | Anyone who has installed software on a computer

has probably done so with the help of a wizard. A wizard is an

interactive program that supplies a sequence of dialog boxes

allowing the user to enter information or choose certain op-

tions. Wizards guide the user through each step required to

complete a particular task.1

32

Usability instead of futility Come on, who really uses all the functions

on their cell phones anyway? Or how about this: name one person who

actually knows how to program a VCR. “Forget it, honey; let’s just go to

the video store.” Sound familiar? In sheet metal fabrication, a malfunction

or someone’s inability to use a machine can cost a lot of money. Usability

has a huge impact on productivity and customer’s purchase decisions.

In the operating system of a sheet metal working machine,

wizards make themselves indispensable by helping users

carry out routine tasks by:

• Dividing a complex process into steps that are

completed one after the other

• Prompting the user to provide information in stages

• Giving the user additional instructions on how to

perform a certain operation

Because of the way they work, wizards can often be more

effective than other software help functions in performing

certain tasks. Not only do they provide a way for inexperienced

users to operate the program intuitively, but also ensure that

all the required information is input. Experience shows that

users value the help of wizards because of the way the wiz-

ards structure and simplify the work sequence.

DIAGNOSTICS

It is impossible to eliminate the possibility of a machine mal-

function ever occurring. If the machine stops suddenly during

production, a frantic search for the cause begins; every minute

of downtime costs the fabricator money.

Operating systems can help to find the cause of the prob-

lem. For each malfunction, the operating system generates a

detailed error message containing:

• An image or graphic indicating the location of the error

• An explanation regarding both the cause and effect of

the malfunction

• Information on how to correct the error

Using this system, operators and service technicians are now

able to fix problems faster and more reliably than they could

only a few years ago.

207


Making the connection

The machine can exchange data and communicate over the network both within the company and beyond.

PART OF THE IT INFRASTRUCTURE

Even after making the leap to the computer age, machine

control systems initially remained islands unto themselves;

the only way to get the necessary data to the machine was

to use floppy disks or other storage media.

Meanwhile, in the rest of the company, a network of comput-

er workstations, servers, cables, and programs was gradually

taking shape. Very soon, it became clear that the machines

would somehow have to be linked to this network in order to

enable access to the continuous data flow that is part of the

sheet metal process chain. Today, such networks are what

make it possible to create a program in the design depart-

ment, store it centrally from where it can be retrieved, and

then run the program from the machine on the factory floor.

At the corporate level, the machine is now able to commu-

nicate with other network users. To expand the range of

communication possibilities, the machine is connected to

the global information highway over the Internet and through

telephone / cellular phone networks.

Requirements | Integrating the machine into the corpo-

rate network poses several challenges to system and network

administrators. First, the machine must be able to understand

the transmission protocol used in the company’s network. For

this reason, the machines support multiple protocols such as

TCP / IP and IPX / SPX.

In addition to this, the corporate network also has to be

configured. During configuration, it is necessary to take into

consideration the existing network infrastructure, firewalls,

routers, gateways, and so forth. Once these obstacles have

been cleared, the road is open for data exchange both within

the company and beyond.

TEXT MESSAGES FROM THE MACHINE

Because of increased automation, an ever-growing number

of machines are capable of operating independently without

human intervention. During “lights-out” operation at night or

over the weekend, a very small number of operating person-

nel are actually present at the production facilities. Often a

single person is responsible for an entire group of machines.

In addition, he or she may have other tasks to perform, so

that there is no time to constantly monitor machine activity.

During this time, the machines are left unattended.

Communication gaps | By the time someone finally no-

tices that a malfunction has occurred or that the machine

has stopped, it is often too late. Fabrication of faulty parts

or production downtime is usually the result. One cause of

this problem is that the operator can only view information

about a malfunction or the production status by going direc-

tly up to the machine and checking the information there. If

no one happens to be near the machine, the malfunction

goes unnoticed.

How can this situation be avoided? One way is to have a

machine that not only displays status and operating informa-

tion on the screen, but also sends this information to people

at other locations. Another way is to log all of the information

during production, so that it is possible to pinpoint errors and

downtime later on.

Machine manufacturers now offer systems that perform

these functions. The systems log and archive information

about the entire production process and are able to send the

data by e-mail, text message, or fax. Different types of infor-

mation are sent through different channels, depending on the

processes within the company and the information needs and

communication habits of the employees.

So how does it work? | The machine sends information

such as the production status or error messages to the infor-

mation server via a data interface. The server is a computer

that is linked to the network and equipped with special soft-

ware. It performs two tasks:

• It stores all incoming information in a database.

• It sends information according to freely definable rules

via the telephone network, cellular phone network, or

through the Internet.

REMOTE DIAGNOSTICS

Machine manufacturers today are taking advantage of new

communication possibilities with the machine to improve ser-

vices and facilitate machine maintenance.

Online, on-site | Telepresence is an approach aimed at

providing direct communication, improved service, and faster

assistance. Telepresence allows service technicians who may

be thousands of kilometers away to communicate and inter-

act with the machine as if they were there on site.

Anyone who has ever tried to explain a problem to the

manufacturer’s service representative over the phone knows

just how difficult it can be to describe a malfunction accura-

tely. Telepresence gives service technicians on the other end

of the line direct access to the information they need and,

in ideal circumstances, enables them to correct the problem

immediately. Telepresence requires remote access to the

machine control. In addition to remote operation, technicians

can rely on the help of webcams for images of the machine

and the fabricated parts. Direct telepresence has proved reli-

able in practical use.

Typical applications are:

• Remote monitoring | Accessing information about

things such as the production status or malfunctions

• Remote control | Using the control from a remote

location to perform tasks such as making settings or

correcting malfunctions

• Remote maintenance | Executing test routines for

machine maintenance without the need for the service

technician to be acutally on-site

Troubleshooting | If operators want to inform the service

team about a problem, they can send an e-mail directly from

the machine. The operator fills out a special electronic form

to describe the problem involved. The control then automati-

cally attaches additional information such as logs and error

lists as well as information about software versions and the

machine configuration.

The advantages of this system over previous notification

methods:

• The message can be sent even if the service technician

is currently not available.

• Information is provided in electronic form, which makes

the information easier to process.

• The service technician has a chance to make prepara-

tions before calling back or using telepresence, making

the process more efficient.

1 Service technicians do not actually have to be on site to assist the

customer. Telepresence enables online access to the machine.

1

“TEXT ME”

Joachim Schmidt, owner of a small sheet metal fabrication

shop, sits at his desk late one evening trying to finish up

some administrative work. Next door in the shop, the laser

cutting machine is running automatically. The machine should

be done in about an hour, and then Joachim Schmidt will

start the next job to keep the machine busy through the

night. Suddenly, a text message appears on his cell phone:

the machine has stopped because it has run out of cutting

gas. Joachim Schmidt immediately gets up to change the gas

cylinder. With everything running smoothly again, he returns

to his desk to finish his work.

This is how control developers envision work with the new

generation of machines. Now with the ability to communicate,

the machines are moving from simple processors of informa-

tion to active providers of information.

“For this to work, the machine requires a suitable interface.

Then it can access information services over the company’s

network and send short messages, e-mails, or faxes – even

worldwide,” explains Klaus Bauer, head of HCI System Devel-

opment at TRUMPF Werkzeugmaschinen GmbH + Co. KG in

Ditzingen. Nevertheless, given the flood of information that is

available today, certain questions need to be considered. For

example, when should the machine send information and to

whom? And what kind of information is actually relevant?

The benefits increase as the degree of system automa-

tion grows. Closing information gaps is a primary aim. Bauer

elaborates: “Machines frequently operate autonomously for

several hours at a time in situations where, previously, an op-

erator was always close by and kept an eye on the progress

of the machine. Today, the operator no longer has to be right

next to the machine. In large companies, a single operator is

often in charge of several machines at once and sometimes

has to complete certain administrative tasks. This means that

the operator no longer knows exactly what each machine is

doing at all times.” Because of this, status information and

alerts are the most important pieces of information that a

machine can provide. Alerts make it possible to move quickly

to solve the problem. Status information, meanwhile, aids in

optimizing processes, even at an administrative level.

Another example: Karin Baumann is responsible for sev-

eral punch presses, all of which run automatically. In the past,

she had to constantly monitor the production status of each

machine and inform the manager whenever a job was finished.

Now the machines send her a text message once the job is

complete. At the same time, an e-mail is sent to the shop

manager, who can start planning delivery.

What is the machine doing right now? Text messages keep you informed.


Technological whiz kids

1

Animated figures, or avatars, assist the user.

Higher performance | Advances in semiconductor and

IT technology are bringing forth increasingly smaller hard-

ware components with more computing power and memory.

This is a trend that will continue in the years to come.

Re-distribution of control tasks | New hardware com-

ponents will have an impact on the evolution of control systems.

We may even see the NC fully assume the tasks performed

by the PLC. At the same time, mechanical elements such as

sensors are being equipped with their own controls, which

are linked to the main control. The current trend points to-

ward networks of small control units that work in parallel,

thereby enhancing computing power and speed.

Human-machine interaction | In future, the complex

system of controls will still have to be operated by humans.

As a result, the cost of software development by machine

manufacturers will continue to rise. The forms of interaction

between humans and the machine will evolve along with the

user software itself.

Avatars, or virtual assistants | Experts in the field of

human-computer interaction understand how valuable virtual

assistants can be in enabling the intuitive use of software.

Avatars are animated figures that appear on the screen. They

react to commands given by the user and provide help if

needed. Avatars combine program navigation and help in

one. The use of such assistants is becoming more prevalent,

even though they can sometimes be more of an irritation

than a benefit. It remains to be seen to what extent avatars

will become established in the machine tool industry. For the

time being, the use of interactive wizard programs and opti-

mized error diagnostics appears to satisfy current needs.

Augmented reality | Augmented reality, or mixed reality, is

a type of virtual reality that alters or “augments” the user’s field

of vision. Additional information such as computer-generated

text or graphics is integrated into the visual environment

and perception.

This technology is already used today in servicing aircraft.

While the service technician is looking at the part that needs to

be checked, he also sees the information required to perform

specific tasks. For example, red arrows or circles indicate

which components need to be inspected, and short sentences

describe what needs to be done.

1 Voice control: the machine does what you tell it to do.

2 Augmented reality: operators wear special glasses.

3 Information is integrated into the operator’s field of vision.

2

The technician wears special glasses equipped with a video

camera and display system. The camera tracks the move-

ment of the technician’s eyes.

The display system shows information relevant to what

the technician is looking at. The information can be displayed

either on the lenses of the glasses or projected directly onto

the retina of the technician with a low-level laser. Laser beams

are used because they can be guided accurately and they

generate precisely defined shapes. The laser light, however,

is so weak that the retina processes it just like any other light

signal coming from the surrounding environment. The user

does not feel a thing; he only sees more. Augmented reality

may also establish itself as a maintenance method in the

machine tool industry.

Voice control | Wouldn’t it be great if you could just say

what you wanted to do instead of pressing an array of but-

tons? Voice control makes it possible. Today, voice recognition

systems can correctly understand hundreds of thousands

of words and are even able to deal with different accents or

dialects. A critical aspect of this technology is ensuring the

reliable recognition of the voices of specific individuals. This

is important because the operator currently working on the

machine is the only person who knows which command

needs to be given next. If several people are all speaking to

different machines on the shop floor at the same time, there

is the risk of the machine interpreting the words of others as

a command. This could create a dangerous situation for the

user if the machine unexpectedly starts performing a differ-

ent action or moving in another direction.

Listening to control developers and specialists in human-

computer interaction talk about their vision for the future can

sound like something straight from a science fiction novel.

But who knows; perhaps we will see some of these ideas

used in sheet metal fabrication in the years to come. But, as

the past has often shown, only time will tell.

3


misc controlsc control

Documents