ebook fjweiland remanufacturing automotive mechatronics and electronics
TRANSCRIPT
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Editor: Fernand J. Weiland
Remanufacturing AutomotiveMechatronics & Electronics
Not a threat but an opportunity
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Table of Contents Foreword By the Editor ..3 Preface By Prof. Rolf Steinhilper ..5 Remanufacturing New and Future Automotive Technologies By Fernand J. Weiland...13 Selected and Applied Test and Diagnosis Methods for Remanufacturing Automotive Mechatronics and Electronics By Dr.-Ing. Stefan Freiberger35 Sustainable Development by Reusing Used Automotive Electronics By Fernand J. Weiland .....83 Research of Internet & Scientific Databases on Reusing and Inspection of Used Electronics Fernand J. Weiland ...89 Remanufacturing of Mechatronic and Electronic Modules for Transportation Vehicles Challenges and Opportunities By Rex Vandenberg..................97 Remanufacturing Electronic Control Modules Evolution in Progress By Joseph Kripli.111
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FOREWORD OF THE EDITOR
As the Chairman of the Automotive Parts Remanufacturers Associations Electronics &
Mechatronics Division, it is my objective to ensure that our members enjoy the benefits of
their membership. Among the many services an association can provide such as lobbying,
facilitating networking opportunities, publishing newsletters and newspapers, etc., I
decided to focus my efforts on technical communications. My objective is not to educate
our members on existing products which they are already familiar with, but to inform them
about future product changes and encourage them to embrace new technologies.
As a new division, the Electronics & Mechatronics Division has enjoyed tremendous
industry support which has been reflected by the large attendance at our meetings. Since
our start in 2006, we have had many meetings, clinics and plant tours. I would like to give
special thanks to all those who have contributed their time and talent as board members,
as speakers, and plant owners. They all have significantly contributed to the success of
this division. To encourage all members of our association to embrace the new E & M
technologies, I decided to edit a small book with the aim of exploring the changes which
will happen to their product lines.
Many thanks go to my friends and true professionals, Joe Kripli from Flight Systems and
Rex Vandenberg from Injectronics, who have greatly contributed to this book and to our
clinics, it is always a joy to work with them. Special thanks and gratitude also go to Stefan
Freiberger, a young, brilliant engineer who has significantly contributed to this book as
both author and technical editor. My debt is also to my friend Rolf Steinhilper, who has
supported me with his advice throughout the creation of this book, and has shared my
enthusiasm for remanufacturing for the last 20 years.
Lastly, many thanks to all the participants to our clinics,
to Bill Gager, President of APRA and his staff, in
particular Global Connection editor Kirsten Kase, who
have helped me in getting my job done as the chairman
of our division and as the editor of this book.
Fernand J. Weiland Chairman APRA Electronics & Mechatronics Division
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Preface By Prof. Rolf Steinhilper
Three areas: 1. Service Engineering (a new scientific discipline discovered only recently),
2. Automotive Maintenance (a task undergoing radical changes because of the
introduction of electronics and mechatronics into cars) and 3. Remanufacturing
Technologies (also challenged by cars electronics and mechatronics) form the
background of this very interesting new book edited and composed by Fernand Weiland.
After outlining the key challenges, it presents new technologies and opportunities mainly in
the field of remanufacturing automotive electronics, profiting from the pioneering spirit and
the expertise of a handful of innovative personalities around the globe who are willing to
share their knowledge with those who are also taking part in this exciting journey.
So it is a real pleasure and honor for me to give some introductory remarks in a preface to
this book, which I hope to be the ignition for inspiring a sequence of more good news and
valuable information for the rapidly developing remanufacturing technology of automotive
electronics and mechatronics.
1. SERVICE ENGINEERING A NEW SCIENTIFIC
DISCIPLINE
The term Service Engineering has now been around for a little more than ten years,
describing a challenging and fascinating field of work besides the engineers classic
disciplines such as design engineering, manufacturing
engineering or industrial engineering.
Being a huge new field, Service Engineering is defined in the
academic world as the systematic development and design of
services using appropriate models, methods and (software) tools.
Given this definition, Service Engineering is positioned in-
between engineering and economic sciences. Thus it is driven by
both the transition from production-based to service-oriented
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economies as well as by the possibilities of new information and communication
technologies such as B-to-B and B-to-C activities via the internet.
Service Engineering and in particular Technical Service Engineering for cars aims at
developing processes for maintaining a cars performance (and thus also its energy
consumption and emissions) on the levels it was designed for, as well as providing know-
how and spare parts to fix failures (and thus reach or even extend the products desired
lifetime) it is therefore of real significant economic and ecologic relevance within the total
life cycle of a car.
So far, however, scientific research & development efforts towards innovative Technical
Service Engineering is still a widely unexplored territory but the potentials are both huge
and promising.
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2. AUTOMOTIVE AFTERMARKET SERVICES
BUSINESS OF WORLD SCALE AND SCOPE
The so-called automotive aftermarket the business of car repairs and spare part
supplies is of wide scope: both in volume and in secrecy (!).Regarding sales, the global
automotive aftermarket business is worth 600 billion Euros (850 billion US $) which means
only around one third of the size of the global automotive business. But as figure 1 shows,
that regarding profits, the automotive aftermarket contributes three times as much than
new car sales to the profits of the automotive business!
Figure 1: Automotive Service How big is it?
0.3% Used car
warranty
12% Sale of used
cars
17% Sale of new
cars
17% Financing, insurance
13% Fuel, oil,
tyres
41%
Spare
parts, service
Originof profits in the automotive industry
Global aftermarket worth over EUR 600 billion(= USD 888 bn = JPY 94,653 bn = CNY 6,315 bn)
Aftermarket equals 1/3 of the global automotiveindustry turnover of EUR 1,889 billion
Continued growth over the coming years
Aftermarket makes up more than 50% of profits
Source:
Booz Allen Hamilton from Automobilwoche no.12 (2005) and OICA (2007)
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The majority of the automotive service and spare parts business, to some extent
depending on the geographical region it is operating in, is done by the so called IAM
(Independent Aftermarket), not primarily by the OEM/OES (Original Equipment
Manufacturer/Supplier), see figure 2.
Figure 2: Independent Aftermarket (IAM) vs. Original Equipment Services (OES).
This competition between OEM/OES and IAM is tough, but it is of course good news for
both technological progress and service innovations for the customers/car owners.
3. TECHNOLOGICAL TURNAROUNDS OF AUTOMOTIVE
MAINTENANCE AND REMANUFACTURING
TECHNOLOGIES
The rapid introduction of computer controls, which operate engine and power train
management, assist driving, steering, braking, suspension and many other safety,
transmission and/or comfort functions in todays vehicles, is challenging both service
operations and skills along the cars life cycle as well as remanufacturing technologies and
54%
81% 82%
59%
80%66%
0%
20%
40%
60%
80%
100%
Original Equipment Services (OES)
Independent Aftermarket (IAM)
Market shares of Independent Aftermarket (IAM) and
Original Equipment Services (OES) in 2005
Source: GEP (2005)
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the involved failure diagnosis requirements. Figure 3 depicts the radical shift (or
technological turnaround) of automotive maintenance operations.
Figure 3: Automotive Service Engineering New Technologies and Opportunities.
Many, if not most of these changes in automotive maintenance are caused by the
introduction of microcontrollers, electronic and mechatronic components for more and
more car functions.
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The remanufacturing technologies for such electronic and mechatronic components in
todays and tomorrows cars also need to be improved and will see some significant
changes and extensions in the near future. These developments are the focus of all
following chapters of this book so no details will be pointed out in this preface.
It should be stated, however, that many recent Research and Development projects which
are run together with OEMs/OESs and the IAM at the Chair Manufacturing and
Remanufacturing Technology at the University of Bayreuth, Germany, where Prof. Dr.-Ing.
Rolf Steinhilper and his team of 10 engineers also operate a European Remanufacturing
Technology Center, deal with the development of new remanufacturing technologies and
business opportunities for automotive electronics and mechatronics. The contents and
results of all these projects are clearly showing that in the intersection between up-to-date
know-how from the three areas Service Engineering, Automotive Maintenance and
Remanufacturing Technologies, many new opportunities arise, see figure 4.
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Figure 4: Automotive Maintenance Operations.
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4. ENJOY READING!
Already today most world class companies have remanufacturing operations to boost their
own productivity and competitiveness in the service sector. But remanufacturing is also a
business for the small, family-owned, local companies, which are the backbone of every
national economy. Small innovative remanufacturers often tie the most intelligent knots in
the global players networks.
Remanufacturing is an eco-innovation driver, with potentials on the economic and the
environmental sides as well. It will conquer new disciplines and new product areas like the
car electronics and mechatronics and open new markets.
We must also remember that the strongest driving force in our market place is always the
consumer technological push needs marked pull. Remanufacturing technology
matters, but not as much as the people who will buy the remanufactured components and
ultimately benefit. Fortunately, consumer research also indicates a rising awareness which
is more than just lip service towards protecting the planet; particularly if customers can
have some fun and save money at the same time. Remanufacturing offers this magic twin
opportunity.
So I am very grateful to my friend Fernand Weiland for publishing this book but not only
my thanks go to him but all the other authors for undertaking this effort.
My best wishes mainly go to the readers of this book for their interest in the further
advancement of the great concept of remanufacturing. There is a strong potential for
growth the kind of healthy, balanced growth we need.
Remanufacturers are in business at the right time in the history of the world to provide
answers to many of our economic, environmental and employment challenges. Enjoy
reading, grasp the opportunities in the areas of vehicle electronics and mechatronics and
take action!
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REMANUFACTURING NEW AND FUTURE AUTOMOTIVE TECHNOLOGIES
By Fernand J. Weiland, FJW Consulting, Cologne Germany)
1. A NEW DEFINITION FOR REMANUFACTURING
AUTOMOTIVE ELECTRONICS AND MECHATRONICS
Until the advent of mechatronics and electronics controllers, the definition for automotive
remanufacturing was clear:
A remanufactured automotive component is the functional equivalent of a new component
and according to the Automotive Parts Remanufacturers Association (APRA)
Recommended Trade Practice the exact definition was, Remanufacturing means
renovating used vehicle parts or components in accordance with the generally accepted
state of the art so that they can perform their function similar to new ones.
Remanufacturing regularly consists of dismantling the used units into their components,
checking these components, repairing defective components or replacing them with new,
reassembling the units, readjusting as necessary and submitting them to a final test. The
unit will be reassembled in such a manner that it is returned to its original status and
performs like new.
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Figure 1: Remanufacturing process steps.
This definition, created for traditional remanufacturing, in the future will also apply to
mechatronics, however, for electronic controllers the definition will have to be adapted.
Electronic controllers, also called electronic control modules/units (sometimes colloquially
called black boxes), are computers equipped with passive and active electrical/electronics
components. They do not have mechanical components and therefore the need to
completely disassemble the entire unit is not necessary. When an electronic unit needs to
be opened, the cleaning will normally be light, since the units are hermetically sealed.
Defective components will need to be changed with new, and some critical components
may also be changed out completely for safety or reliability reasons. In this context it is
interesting to note whether electronic control units which have already been used and
continue to work properly can be reused again without any intervention. The German
Fraunhofer Institute IZM has studied this criteria and an interim report is available in this
book.
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2. REMANUFACTURED PARTS ARE THE BEST
CHOICE
Figure 2: Remanufactured Parts.
To service and repair motor vehicles with used parts or repaired parts is not the best
choice. Used parts have not been corrected for any potential problems. They have a
limited life expectancy. Not only will it not be an economical choice to use these parts, but
most importantly it can be an unsafe replacement. Furthermore, used parts procured from
car dismantlers are generally not easily available. Repaired parts have not been fully
disassembled, inspected or rectified -- their full function is not certain however, they are
an environmentally friendly alternative, but not without risks to the buyer. New parts are
not the best economic choice either, because they are more expensive then
remanufactured units and they are surely not an environmentally friendly alternative.
Remanufactured parts are simply not only the best choice and the best buy, but
environmentally the only viable alternative. Remanufacturing saves material and energy
and the parts are (re)manufactured to high quality standards. In comparison to
manufacturing new units, remanufacturing uses 90% less material and 90% less energy!
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Figure 3: Vehicles in Europe and USA.
3. GLOBAL POTENTIAL SALES FOR AUTOMOTIVE
REMANUFACTURED PRODUCTS (AND
MECHATRONICS)
Globally speaking, the biggest market for remanufactured products is North America.
Europe is number two and the rest of the world is only an emerging market. In the United
States remanufacturing has been in place since 1940 and has steadily developed over the
years. Today the market is mature and remanufactured products have established a
dominant position against new, used or repaired units. In Europe remanufacturing has not
reached the same level, though the introduction in the United Kingdom dates back as early
as 1945 and in Germany, 1947. The main reasons for this slower growth have been that
Europe has been a market where garages tended to repair rather than use
remanufactured units. However, in recent years this trend has changed and the popularity
of remanufacturing is now progressing well.
The question for America and Europe is how will the new technologies of mechatronics
and electronics influence remanufacturing? Will the higher technological barriers hinder
the development of remanufacturing? At this juncture no one can reliably predict which
position remanufacturing will hold in 15-20 years. But encouraging all remanufacturers to
embrace the change now will not only mean challenges but also opportunities. As an
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association APRA has decided to facilitate education and networking in support of these
technological developments.
Figure 4: European annual production of remanufactured units.
4. EUROPEAN FUTURE POTENTIAL FOR
REMANUFACTURING
In terms of communicating volumes or number of units remanufactured every year, there
are very few reliable sources. APRA is one of the only sources available, and quotes for
North America a market of 60 million units each year and for Europe 20 million. If one
considers that the number of vehicles in use in the United States is around 200 million and
in Europe approx. the same number, one can asses that the potential in Europe leaves
room for growth. However, an accurate estimation of further growth is difficult because too
many factors will influence the development.
The positive short/medium term growth will certainly come from products like air
conditioning compressors, automatic transmissions, etc. These product lines will
increasingly equip more and more European cars and a new potential for remanufacturing
will emerge. A further area of growth is expected to come from components for heavy duty
vehicles. Potential growth is also expected in the areas of Eastern and Southern Europe
where remanufacturing is not yet as highly developed as in other parts of Europe. APRA
estimates that by the year 2015 the total European volume will reach 30 million units.
Compared to the year 2000 this is two times more! Beyond this date it is difficult to predict
the future of remanufacturing due to the potential impacts of mechatronics and electronics.
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Figure 5: Potential units to be remanufactured.
5. TRADITIONAL REMANUFACTURED PRODUCTS
The list of parts which have traditionally been remanufactured, also called hard parts, is
long (see table above). Most are mechanical and hydraulic parts, however, electrical parts
like electrical starter motors and electrical generators represent a significant part of
traditional remanufacturing. They all have been fitted to our vehicles for many years and
over time they have only slightly changed in technology. Remanufacturers have always
been able to cope with technical changes. By nature remanufactures are very inventive
and creative and when original technical specifications for products are not available for
remanufacturing, they perform reverse engineering, a great capability which
remanufacturers have. Over the years remanufacturers have invested in very
sophisticated tools, not only for the remanufacturing process, but also for the extremely
important work of testing the final quality of their products. All of these capabilities will help
them when they face the important change from traditional components to mechatronics
and electronics.
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Figure 6: Remanufacturing product life cycle.
6. THE REMANUFACTURING PRODUCT/TECHNOLOGY
LIFE CYCLE
In remanufacturing every product line/technology will follow a life cycle, from new/future
products, to current products, to mature products, and finally to phasing out products.
With products maturing, the remanufacturing volume will increase and so will productivity
and profits. At the end of the cycle they will phase out, and at that time the volume and
prices will decline and the product will become a niche product. Electrical power steering,
for example, are new/future products which will definitely increase in volume over time
and follow the above outlined cycle. But at the same time the traditional hydraulic power
steering, which is a mature product, will decrease in volume and finally will phase out and
be replaced by these new electrical power steerings. Most of the time phasing out is due to
changing technology. Volume reduction can also be caused by increased original product
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reliability, causing the volume required for servicing/repairing cars to decline. The
profitability of reman components will vary significantly during their life cycle. At the start,
when up-front investments and learning cost are high, profitability will be low, but with
higher volumes, due to economies of scale, the margins earned will reach the highest
value. Future mechatronics remanufacturing will follow this path and when it reaches the
volume production phase the earnings will be very attractive.
Figure 7: Evolution of vehicles in use. Over a period of ca. 15 years the conventional hydraulic power
steering will gradually be replaced by the electrical assisted power steering (EAS).
7. HYDRAULIC POWER STEERING VERSUS
MECHATRONICS POWER STEERING
A typical example to demonstrate the changes of a component during the life cycle is the
power steering fitted to the Volkswagen Golf cars. Until 2005 this model was fitted with
traditional hydraulic power steering, but starting in 2005 Volkswagen decided to install a
completely new technology: the electrically driven and electronically controlled power
steering. This is a typical example of a traditional component which was converted to a
mechatronic unit. The number of cars in use, which still have hydraulic power steering, is
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very significant and it will take up to 10-15 years until all Golf in use are equipped with the
new mechatronic version. Despite this, remanufacturers must embrace the new
technology now if they wish to stay in this business. Volkswagen is not the only OEM
changing to mechatronics power steering. Fiat, Opel and others have changed to the new
technology in 1998 and the aftermarket, i.e. remanufacturing business, for these units has
already started.
Figure 8: Mechatronics units.
8. WILL THE COMPLEXITY OF MECHATRONICS BE A
THREAT FOR REMANUFACTURING?
The list of automotive mechatronics components is as long as the list of traditional
components because any mechanical, electrical or hydraulic component will be replaced
by electronically controlled components, if it hasnt happened already. The reasons for this
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are many since car components need to become more efficient in terms of energy
consumption, safer, smaller in size and weight and faster. The only way to improve all
these parameters is to control the units electronically and make them part of an
interrelated car network.
Furthermore, electronic control will also allow the customisation of car functions. By
changing the software instead of the hardware - which is much easier - an opportunity to
install and add additional features requested by the owner/driver of the car will be
presented to the technician. The downside of this will be the proliferation or increased
number of specific applications (part numbers) for each component and the question could
be asked if these changes or challenges are not too many or too big for the
remanufacturer to cope with. With the right determination and the right investment
remanufacturers can manage all this. In fact it will not be the first time the industry will be
dealing with such paradigm change, after all they have successfully managed the change
from mechanical carburetors to electronically controlled engine management systems,
which was quite a challenge
Figure 9: Bosch exchange program (source: Robert Bosch) Bosch is a very committed supplier of
remanufactured products which they call Exchange. Remanufactured Electronic Controlled Units
and Ignition Distributors are only two lines of many other product lines which they offer.
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9. WE ALL CAN LEARN FROM THE
REMANUFACTURERS OF ENGINE MANAGEMENT
SYSTEMS
Engine management systems (EMS) control the fuel injection, the ignition and the
emissions of combustion engines. In total the number of functions which they control is
approximately 100. The systems consist of many sensors and actuators and a computer or
Electronic Control Unit (ECU). These days nearly all cars are equipped with an EMS
system. When the change from carburetor to electronic injection happened 25 years ago,
some remanufacturers (Original or independent remanufacturers) did not hesitate to
embrace the change. They were not afraid to go through a difficult learning phase and they
were not reluctant to make the investments which such a new business required. In this
book you will be reading contributions made by two of these pioneers. The
remanufacturing processes which they invented were more on the electronic side and less
on the mechatronic side which were not yet developed. They now remanufacture all the
different types of controllers and the pertaining actuators which are the precursors of the
future mechatronic reman business. They are living evidence of what can be achieved by
remanufacturers who are determined to accept high challenges. They are the proof of
what remanufacturers often say, In remanufacturing nothing is impossible! My conclusion
is, what has been done for electronics can also be done for mechatronics!
Figure 10: TRW Electrically Assisted Steering (EAS) which is electrically column driven designed for
smaller vehicles (source: TRW Automotive).
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10. REMANUFACTURING MECHATRONICS IS A
FASCINATING PROCESS
What exactly is a mechatronic unit? It is the combination of a mechanical component with
an electrical actuator which is electronically controlled. The word mechatronics means a
combination of the words mechanics and electronics. Basically a mechatronic unit is
also a control system which, in automotive applications, is often a part of an entire vehicle
interconnected network. One of the first mechatronic automotive components which is
already finding its way into remanufacturing is electrical power steering! During driving,
power steering components are constantly actuated; therefore the need for service or
replacement often becomes necessary. This makes these components very attractive to
the remanufacturing business. The major Tier one manufacturers of these new
mechatronic components are ZF, Bosch, TRW, NSK and Koyo. These companies have all
designed different systems for different vehicles which have already been in production for
a number of years.
Figure 11: Elements of the TRW electrical column driven power steering: the electronic controller, the
angle sensor and the electrical motor actuator.
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11. ARE MECHATRONICS REALLY SO COMPLEX?
An Electrical Assisted Steering (EAS) system may look complex, but not so if we analyse it
component by component. The system can be divided into three major units:
1. The sensor which is part of the steering column that measures the angle the driver
makes in turning the steering wheel;
2. The Electronic Control Unit (ECU) which processes the sensor data information and
calculates and supplies the power,
3. The electrical motor which will rotate the column, that will drive the rack, and turn the
wheels of the car.
This automotive system is no different from many other control systems which we have
used for many years in all sorts of non automotive applications. In remanufacturing, the
three components of the EAS unit will be processed separately and each will be inspected,
repaired and tested. Repairing electrical motors is not new to remanufacturers and
rebuilding an ECU, as we have seen previously, is a process which remanufacturing
specialists are very capable of performing. After remanufacture and reassembly of all three
components into a complete unit, a final test will ensure the proper functioning of the unit.
This last check is one of the most important steps for the remanufacturer. Specialized
manufacturers of test equipment will provide the perfect piece of equipment required to do
this final job.
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Figure 12: Electronic control unit of an electrical power steering pump.
A micro controller of an electrical power steering pump and the frequency of potential
failures (defects) which need to be repaired during remanufacturing. Out of 100 units
which are returned for reman, only 10 units will have a defective microcontroller, 25
defective wiring or connectors and 40 units will show a problem with the power supply
modules.
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12. WHAT CAN GO WRONG IN AN ECU AND WHAT
NEEDS TO BE REMANUFACTURED
An ECU (electronic control unit) for a standard mechatronic unit like an EAS is significantly
less complex compared to an ECU for EMS. The number of parameters it controls or
computes is limited as are the number of electronic components. In total, the number of
passive and active components is modest. As a result the number of potential failures on
an ECU for an EAS is often limited to the more passive components like:
- connectors - for many reasons they are a weak point in any electronic unit;
- the wiring - mechanical stress and corrosion can cause a lot of problems, and
- the power supply - which consists of an often easy to diagnose and easy to replace
component.
The microcontroller itself is often the last source of complaint. Electronic semiconductors
(microchips, etc.) normally last forever. It is the electrical connections which are basically
mechanical connections that are often the problem makers!
Assuming the remanufacturer has the equipment and the data to test the unit, the
remanufacturing process of this ECU should not present them with a major problem.
Figure 13: TRW rear axle caliper is a combination of a hydraulic brake and an electrically driven parking
brake (source: TRW Automotive).
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13. AFTER EMS & EAS WHICH ARE THE NEXT
MECHATRONIC UNITS APPEARING IN
REMANUFACTURING?
After EMS (Engine Management Systems) and EAS (Electrical Assisted Steering) the next
interesting area we need to look at is braking. A mechatronic braking system which has
already existed for a number of years is ABS, a braking system which has mechatronic
components, like electrical solenoids and an electronic controller. Not many
remanufacturers are remanufacturing these components because the reliability and the
number of service incidents are so low that the volume for remanufacturing is not sufficient
to justify the investment to reman on a larger scale.
With the introduction of the combined hydraulic/electrical brake caliper (see figure16),
which is also a parking brake, remanufacturing mechatronics will enjoy a new business.
Calipers are components which are highly stressed and the frequent service and repair
that they require will make them an important mechatronic component for remanufacturing.
These electrical calipers have a hydraulic piston coupled with an electrical motor and a
gearbox. Not too complex for remanufacturing, but as for all mechatronics, an electronic
tester for inspecting and operating the calipers will be absolutely crucial. Fortunately such
testers exist already.
Figure 14: Side-mounted combined starter-generator with the electronic controller designed by Valeo
(source: Valeo Automotive).
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There are many other areas where mechatronics will be applied, but let us look at a last
one which in traditional remanufacturing is one of the biggest reman volume providers, i.e.
electrical rotating machines or starter motors and generators. At this juncture it is difficult
to make an exact forecast of which of the existing new rotating machine concepts will be
fitted to volume cars.
I have chosen to discuss the Valeo design because it is the best example for illustrating
the direction these applications are moving. The Valeo design, which would fit in the
category of so called micro hybrid power train, is a side mounted combined starter-
generator. The mechanical/electrical concept is close to traditional rotating machines
except that it is electronically controlled. Other combined starter generators used for more
powerful applications, the so called mild hybrid power trains, are also controlled
electronically and the challenge to reman will not be very different than the Valeo machine.
The remanufacturing of these new machines will not be such a great problem; the bigger
hurdle will be, as for all mechatronics units, the electronic controller. For Starter-
Generators the controller will in addition be combined with an inverter for supplying the AC
current for the motor mode.
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14. HOW REMANUFACTURERS CAN HELP GARAGE
WORKSHOPS WITH BETTER DIAGNOSIS
The garage workshop is very familiar with remanufactured units which it has used
extensively for repairing cars over the last several decades. Remanufactured units offer an
attractive solution for returning defective cars to service. With the advent of electronics and
mechatronics, remanufacturing will positively expand in so far as the remanufacturer will
not only offer a product to the installer but also a technical service! The reason has to do
with the increased complexity of the units and the daily struggle of the garage technician
with the new technologies. Unfortunately for the garage, not only are the units more
complex but also the entire electrical car connections are now part of a multiplex network
called CAN bus.
Figure 15: On Board Diagnosis (source: Robert Bosch).
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Traditionally, the garage technician repairing cars had the capability to check the
components, but now with all components becoming mechatronics and interrelated, his
testing possibilities for individual components are very limited. One has to rely on what the
car testers will tell them about the status of the car systems, but often they will not tell him
the real status of the individual components. Only the remanufacturer has this true and
clear capability to inform the installer if a mechatronic unit is accurately working or not! As
a result, the remanufacturer can now help the garage to perform a better diagnosis, a
service which is new and will be very appreciated. Smart remanufacturers will offer this
competitive advantage and will be compensated with greater market shares!
Figure 16: Performance of electronic control units (source: Robert Bosch). Over the last 25 years the
performances of electronic controllers for EMS have increased by a factor of 100! In the
same time span, the size/volume of the controllers have decreased five times. This is
practically a specific performance improvement of a factor of 500!
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15. MECHATRONIC COMPONENTS HAVE A MUCH
SHORTER DESIGN CYCLE
If we compare the changes in Engine Management Controllers over the last three
decades, we will see at least three significant paradigm changes (see figure 16). If in
comparison we look at traditional components like Brake callipers, Hydraulic power
steering, etc. we have, until the recent advent of mechatronics, not really seen one
significant paradigm change over a similar period. Brake callipers, power steering and
other components are only now going through a paradigm change, i.e. they will all become
mechatronic components.
To illustrate the current speed of change in the design cycle of electronics (and
consequently, mechatronics) the best examples are personal computers, mobile phones
and digital cameras. We replace these units every 3-5 years, some even more frequently.
Most of the time the reasons for this frequent changing technology is found in the
hardware and software. In automotive design we are seeing a similar evolution. For
example, for EMS (Engine Management Systems) the product design cycles have already
reached a stage of less than three years, according to a study made by the Technical
University of Dresden (Germany).
The bottom line of this evolution will be that design cycles for automotive components will
reduce considerably and OES aftermarket sales & service divisions will be highly
challenged to keep pace with these frequent changes. Fortunately remanufacturing can
easily cope with these challenges. In the past remanufacturers have always supplied the
aftermarket with products. It is not unusual that after more than 20 years after the OE
stopped production, remanufacturers are still capable of offering a reman unit for repairing
cars!
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33
16. REMANUFACTURING IS A RELIABLE AND VERY
ATTRACTIVE SOLUTION FOR SHORT, MEDIUM & LONG
TERM SUPPLIES OF COMPONENTS FOR REPAIRING
VEHICLES
I do not have to reiterate the fact that remanufactured products are an attractive solution for
replacing defective components. I do however, wish to emphasize that for OEMs and Tier
Ones, the mechatronic components which are quickly becoming obsolete, will present an
immense challenge in terms of securing long term (15 years and more) supplies. For them,
remanufacturing will be the best choice and a very cost effective and safe alternative
compared to making new components. They will need to adopt the philosophy to offer
remanufactured units now and not at a later date. They need to create a system for the
return of defective units and they need to retain certain test equipment and data before they
dispose of them. Remanufacturing needs time to prepare, because it cannot happen
overnight when other alternatives, such as small batch production, redesign, produce an all
time batch, etc, have failed!
17. FINAL CONCLUSIONS
Active car components will eventually become mechatronics components. The
conversion has already started and it will take a few years (2-5) until all new cars will
be equipped with them. It will take approximately 10 years until the majority of the cars
in use are equipped with them.
Mechatronics will be a new area where remanufacturers can win a competitive edge if
they adopt the trend early enough.
Traditional remanufacturers do not always have the know-how to tackle electronics
and mechatronics. They need to go through a learning process which will take time. I
recommend to subcontract or to work with the specialized electronics remanufactures
who can give valuable support.
Investments of time, but also of money, are required to make the change. To create a
sound basis for the investment, remanufacturers must create a robust plan.
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34
In the future remanufacturing mechatronics will be an attractive program, not only to
offer to the independent aftermarket but also to offer to OEMs and Tier Ones, who
may decide to subcontract their programs.
Mechatronics are high value products which will deliver higher margins and which will
not be easily copied by low labor countries. The parts proliferation will be such that
high volumes by part number will not be the norm.
Remanufacturers should decide soon if they want to be in the mechatronic business.
Mechatronics needs high dedication; success will only come from embracing the new
technology with determination. Good luck!
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35
Selected and Applied Test and Diagnosis Methods for Remanufacturing Automotive
Mechatronics and Electronics
By: Dr.-Ing. Stefan Freiberger; Bayreuth University
Structure:
1 Automotive Mechatronics
2. Test and Diagnosis in Remanufacturing
3. Test and Diagnosis of Mechatronics in Remanufacturing
4. Test and Diagnosis of Electronic Control Units in Remanufacturing
5. Test and Diagnosis of Actuators and Sensors in Remanufacturing
6. Remanufacturing of Electro Hydraulic Power Steering Pumps
7. Remanufacturing of Electronic Control Unit of an EHPS-Pump
8. Remanufacturing of Air Mass Sensors
9. Conclusion and Outlook
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36
1 Automotive Mechatronics
1.1 Design of Mechatronic Systems
The task of mechatronic systems is the arranged and controlled conversion of electrical,
hydraulic, mechanical, thermal and pneumatic energy. Mechatronic systems are
characterized by at least one mechanical energy flow and one transfer of information. In
order to perform this task, the mechanical, electrical and electronic systems are closely
interconnected, exchanging data through a communication system. The following figure
shows the design of an integrated electronic system, to which literature increasingly refers
as mechatronic system.
Figure 1: Mechatronic systems.
Actuators and sensors represent the basis of the mechatronic system. Through analog or
digital signals, the electronic control units are able to communicate with the control system,
as well as with the sensors and the actuators. They are also built in the mechatronic system.
The properties of the system, e. g. dynamic characteristics, flexibility and learning aptitude
are mainly defined by the software in the electronic control unit.
1.2 Subassemblies within Mechatronic Systems
The following subsections give a closer insight to the actuators, sensors and electronic
control units, which represent the most important subassemblies of mechatronic systems
Mechatronic System
Basic System
Control System
Electronic control unit
Actuators Sensors
Desired values
Actual values Given values Energy,
Information,
Material
Energy,
Information,
Material
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37
1.2.1 Actuator Subassembly
In many cases, automotive actuators comprised of an electronical input and a mechanical
output. The following actuators are frequently used in vehicles:
Electronic actuators: e. g. direct current motors, electronical valves and generators.
Fluid energetically actuators: e. g. valves, barrels and pumps.
With regard to their power-to-weight-ratio, the hydraulic actuators are clearly superior to the
electronical ones. The advantages of electronical actuators are inherent in their convenient
controllability, in their great dynamics, in their good degree of efficiency, the low costs of
production and the good testability. Due to the many advantages of the electronical
actuators, they are commonly used in vehicles, especially in those with medium requirement
of energy. Up to 100 electric motors are already installed in todays luxury-class vehicles.
This trend is to be strengthened and spread towards every vehicle class. Especially
brushless dc motors will be installed in the future, since they posses a higher power density
combined with a good reliability. Hydraulic actuators are used for several rare applications
with a high requirement of energy, e. g. servo steering systems.
1.2.2 Sensor Subassembly
The task of sensors is to measure internal and external signals of a system, to convert these
signals and to send the signals to electronic control units. Most of, electrical signals are used
as sensor output. The value is transmitted by one of the following ways of signals.
For amplitude analogue signals, the amplitude is proportional to the measurand.
For frequency analogue signals, the frequency is proportional to the measurand.
For digital signals, an encoded binary signal can be transformed into the measurand.
Furthermore, sensors can be classified according to their measuring principle. Table 1
shows the commonly used measuring principles in todays vehicles.
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38
Table 1: Measurands, measuring principles and applications in the vehicle.
Measurand Measuring principle (Code of the
measuring principle)
Measuring application (Code
of the measuring principle)
Acceleration Inductive (1), capacitive (2),
piezo-electric (3),
hall-effect (5)
Cross acceleration (2, 3, 5),
Lateral acceleration (2, 3, 5),
Crankshaft acceleration (3)
Revolution
speed
Inductive (1), hall-effect (5),
optical (6), magneto-resistive (10)
Gearbox rotation speed (1, 5),
Wheel rotation speed (1, 5, 10)
Pressure Capacitive (2), piezo-electric (3),
resistive (4), piezo-resistive (7)
Absorbing air pressure (7),
Charging air pressure (4, 7),
Breaking pressure (2, 4),
Flow rate Resistive (4), optoelectronic (8) Air flow (4),
Mass air flow (4)
Lenth,
Distance
Inductive (1), capacitive (2),
resistive (4), supersonic (12),
radar (11)
Accelerator value (1),
Seat adjustment stroke (4)
Clutch stroke (1),
Temperature Resistive (4), optoelectronic (8),
thermoelectrical (9)
Oil temperature(4),
Water temperature (4),
Exhaust gas temperature (4)
Vibration Piezo-electric (3) Knocking sensor (3)
Angle Inductive (1) capacitive (2), Resistive
(4),hall-effect (5), optoelectronic (8),
magneto-resistive (10)
Steering angle (8, 10, 5),
Damper angle (4),
Accelerator angle (1, 4, 5)
The table above shows some sensors that are used in vehicles. Due to the increasing
number of used sensors, the continuing trend is a miniaturisation of the systems - mainly in
order to economise weight and space.
1.2.3 Electronic Control Unit
With the introduction of the microcontroller more and more functions are being transferred to
electronic control units (ECUs). Modern cars may contain up to 100 ECUs, mostly as part of
the complex mechatronic systems used in the power train, safety and comfort systems of
todays vehicles. Optimal interaction between sensors, actuators, and the control units is a
basic requirement for the smooth functioning of the entire system. Unfortunately, in recent
years, the rising complexity has lead to a decrease in reliability and an increase in the
number of call-backs and breakdowns, especially for innovative vehicles. This, together with
the fact that the end-users costs for a single mechatronic system inside their cars range
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39
between 200 and 3000 Euro, provides a strong incentive to remanufacture these
economically.
2 Test and Diagnosis in Remanufacturing
2.1 Remanufacturing Process Steps for Mechatronics
Especially with regard to systems that consist of networked subsystems - like mechatronic
systems, it makes sense to carry out an entrance test and diagnosis of the whole system,
before passing it on to the disassembly. This entrance test and diagnosis as a first step in
remanufacturing mechatronic systems gives information about the condition of the system.
The five common steps in remanufacturing can be added to the step of entrance test and
diagnosis of the system.
Figure 2: Process steps in Remanufacturing.
The entrance test and diagnosis divides the mechatronic systems into the fractions
remanufacturable and non-remanufacturable. During the second process step, the
4 5
1 Disassembly of the System 2
2 3
3 4
Reconditioning of Parts or Subsystems
5 Product Reassembly 6
Entrance Diagnosis of the System
Mechatronic
Systems
Remanufacturing
Process Steps
Test and Diagnosis of Subsystems
Quality Assurance
Final Test
Mechanic and
Electromechanic
Systems
1
Thorough Cleaning
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40
disassembly, the two fractions are disassembled into different levels. Concerning the non-
remanufacturable systems, only the remanufacturable subassemblies (e. g. the sensors) or
parts (e. g. the casings) are disassembled, depending on the entrance test and diagnosis.
The non-remanufacturable parts are passed on towards material recycling or removal. The
remanufacturable systems run through a complete disassembly, a thorough cleaning to the
fourth process step of remanufacturing: the test and diagnosis of subsystems and parts. The
next step is the reconditioning of parts or subsystems and last but not least the product
reassembly and the final test. Having run through the different process steps mentioned
above, the remanufactured mechatronic systems can be delivered to the customer with their
original quality, their original effectiveness, original life-time, guarantee and service.
2.2 Boundary Conditions for Testing and Diagnosis in
Remanufacturing
Some of the remanufacturing companies work in cooperation with one or several original
equipment (OE) manufacturers. In the following, they will be referred to as OE manufacturer-
related remanufacturing companies. The main part of the remanufacturing companies
however is independent from original manufacturers and therefore these companies do not
cooperate with any OE manufacturer. Since the choice of the best methods for the test and
diagnosis of failures strongly depends on the cooperation with the OE manufacturers, the
two types of remanufacturing companies take different ways. Concerning the choice of test
and diagnosis methods, several basic requirements are stipulated for the two types of
remanufacturing companies:
Boundary conditions for OE manufacturer-related remanufacturing companies:
Existence of drawings (control plans, port information, tolerances in geometry, form
and position).
Existence of parts-lists (element designation, suppliers and assemblage Methods)
Existence of specifications.
If necessary: existence of original testing tools and test benches.
Boundary conditions for independent remanufacturing companies:
No access to drawings.
No access to parts lists.
No information concerning specifications.
No access to original testing tools and test benches.
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41
2.3 Steps for the Test and Diagnosis in Remanufacturing
For the test and diagnosis of systems, subsystems and parts, the steps as presented in the
following figure are recommended.
Figure 3: Process steps for the test and diagnosis.
2.4 Methods for the Test and Diagnosis in Remanufacturing
There are a great number of different methods to test technical systems. Each method has
its special force and weakness. In account of technical or economical reasons, not every
known method can be applied in remanufacturing of mechatronic systems and their
subassemblies. The methods can either be divided into norm-based (deductive) and model-
based (inductive) methods or into signal based, signal model based and model based
methods.
Signal based methods are methods that use input, output and internal signals of the unit.
Signal model based methods are methods that use the stochastic coherences of signals or
the vibration behaviour of the signals. Model based methods use a mathematical model of
the system.
The symptoms are defined in such a way that deviations concerning the nominal or
reference state (specifications) indicate failures. In order to carry out an analysis of the
symptoms, every method has to be based on analytic and heuristic knowledge, concerning
the correlation of symptoms and failures. Only in this manner the failures, their nature,
reason, type, location and dimension can be safely diagnosed.
Choice of test and diagnosis methods
Generation of specification
Generation of test cases and input signals
Measurement under realistic conditions
Evaluation of the data
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42
3 Test and Diagnosis of Mechatronics in
Remanufacturing
3.1 Potential Methods for Remanufacturing
The following figure shows potential methods for the test and diagnosis of mechatronic
systems in Remanufacturing.
Figure 4: Potential methods for the test and diagnosis of mechatronic systems.
3.2 Selection of Methods for Remanufacturing
Target of that chapter is to find out the best method or the best combination of methods for
the test and diagnosis of mechatronic systems in remanufacturing companies.
Remanufacturing companies are divided into independent (OE data are not available) and
OE manufacturer-related (OE data are available) companies.
3.2.1 For Independent Remanufacturing Companies (OE data are not
available)
The following table shows the result of an evaluation of the potential methods for the test
and failure detection of mechatronic systems for remanufacturing companies.
Potential test and diagnosis methods for mechatronic systems
Signal Based Methods
Absolute Value
Control
Characteristic
Curves
Signal Model Based
Methods
Stochastic Signal
Model
Spectral Analyze
Model Based Methods
Parameter Estimation
State Condition
Parity Space
Artificial Neuronal Networks
Fuzzy Models
Neuro Fuzzy Models
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43
0 5 6 7 10
Table 2: Result of an evaluation for the test and diagnosis of mechatronic systems
(independent remanufacturing companies)
System knowledge
Efforts for model creation
Transferability
Possible ways of signalling
Failure test
Failure diagnosis
Invest
Duration of test and diagnosis
Efficiency share
Effort for model creation
Efficiency share
Technical effort
Efficiency share
Economical effort
Efficiency
Main Crit. Imp. in % 40 30 30
Single Crit. Imp. in % 37 23 40 35 45 20 55 45
Absolute Value
Control 8,3 8,5 9,2 1,9 5,2 2,0 7,7 5,2 8,7 3,4 6,6 6,5
Characteristic
Curves 8,3 7,9 8,1 8,2 8,9 5,7 6,3 6,6 8,1 8,0 6,4 7,6
Spectroscopic
Analysis 5,0 4,7 7,0 6,3 8,7 5,8 4,6 6,5 5,7 7,3 5,5 6,1
Stochastic Signal
Models 7,3 7,9 3,9 8,4 6,2 2,4 6,0 5,7 6,1 6,2 5,9 6,1
Fuzzy Models 5,0 4,1 6,3 8,8 8,7 4,7 6,0 5,5 5,3 7,9 5,8 6,2
Artificial Neuronal
Networks 8,5 4,7 4,1 10 8,8 6,0 3,2 6,6 5,9 8,7 4,7 6,4
Neuro Fuzzy Models 4,7 2,0 4,1 8,8 8,7 6,6 3,2 6,1 3,8 8,3 4,5 5,4
Parameter
Estimation 1,5 1,9 5,0 10 9,0 10 6,0 8,9 3,0 9,6 7,3 6,3
Parity Space 0,2 1,5 4,2 10 7,4 6,8 6,0 6,5 2,1 8,2 6,2 5,2
State Condition 1,9 2,1 5,0 10 7,4 5,2 6,0 6,5 3,2 7,9 6,2 5,5
The table above shows the summary of all calculated values, as well as the efficiency
shares and efficiencies of all potential methods for the test and diagnosis of mechatronic
systems in remanufacturing.
The following figure shows the recommended methods during the entrance and final test
and diagnosis in remanufacturing mechatronic systems.
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44
Figure 5: Entrance and final test and diagnosis of mechatronic systems for independent remanufacturing
companies.
With expert knowledge, failure trees, results of FMEA analyses, failure data bases and
characteristics of the system in relation to the reference characteristics most of the failures
can be safely detected, localized and diagnosed. It is to note, that the method characteristic
curves can only detect those failures that influence the output signal.
Some failures, as for example cracks and deformations cannot be detected with the method
of characteristic curves. Therefore, a direct visual diagnosis is carried out before the
characteristic curves test, which is able to detect visible structural failures.
Entrance and final test and diagnosis of mechatronic systems: for independent remanufacturing companies
Direct Visual
Diagnosis
Specific
information
resources
Knowledge of
the workers
Specification
(e. g. pictures
of good units,
main failures,
FMEA results)
Gained
information
Localized and
diagnosed
visual and
structural
failures, their
sources and
consequences
Information
concerning the
sorting of the
systems for
further steps
Specific
information
resources
Test and
diagnosis
hardware
Specification
(e. g. input
signals, test
cases, set
output
signals)
Gained
information
Localized and
diagnosed
failures
Information
concerning
the sorting of
the systems
for further
steps
Characteristic
Curves
Systems with not diagnosed failures
Material flow
Systems with non-repairable failures
Systems with diagnosed failures
All systems
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45
0 5 6 7 10
3.2.2 For OE Manufacturer-related Remanufacturing Companies (OE
data are available)
The following table shows the result of an evaluation of the potential methods for the test
and diagnosis of mechatronic systems for OE manufacturer-related remanufacturing
companies.
Table 3: Result of an evaluation for the test and diagnosis of mechatronic systems (OE
manufacturer-related remanufacturing companies)
Possible ways of
signalling
Failure test
Failure diagnosis
Invest
Duration of test
and diagnosis
Efficiency share
Technical effort
Efficiency share
Economical effort
Efficiency
Main Criteria Importance in % 50 50
Single Criteria Importance in % 35 45 20 55 45
Absolute Value Control 1,9 5,2 2,0 7,7 5,2 3,4 6,6 5,0
Characteristic Curves 9,0 8,9 5,7 6,3 6,6 8,3 6,4 7,4
Spectroscopic Analysis 6,3 8,7 5,8 4,6 6,5 7,3 5,5 6,4
Stochastic Signal Models 9,4 6,2 2,4 6,0 5,7 6,6 5,9 6,2
Fuzzy Models 8,8 8,7 4,7 6,0 5,5 7,9 5,8 6,9
Artificial Neuronal Networks 10 8,8 6,0 3,2 6,6 8,7 4,7 6,7
Neuro Fuzzy Models 8,8 8,7 6,6 3,2 6,1 8,3 4,5 6,4
Parameter Estimation 10 9,0 10 6,0 8,9 9,6 7,3 8,4
Parity Space 10 7,4 6,8 6,0 6,5 8,2 6,2 7,2
State Condition 10 7,4 5,2 6,0 6,5 7,9 6,2 7,0
The table above shows a summary of all calculated grades, as well as the efficiency shares
and efficiencies of all potential methods for the test and diagnosis of mechatronic systems.
The following figure shows the recommended methods during the entrance and final test
and diagnosis within the remanufacturing of mechatronic systems.
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46
Figure 6: Entrance and final test and diagnosis of mechatronic systems for OE manufacturer-related
remanufacturing companies.
With regard to OE manufacturer-related and independent remanufacturing companies, the
entrance test and diagnosis as well as the final test and diagnosis are similar. The main
difference is that the OE manufacturer-related remanufacturing companies use the method
characteristic curves, while the independent remanufacturing companies use the method
parameter estimation.
Entrance and final test and diagnosis of mechatronic systems: for OE manufacturer-related remanufacturing companies
Specific
information
resources
Knowledge of
the workers
Specification
(e. g. pictures
of good units,
main failures,
FMEA results)
Gained
information
Localized and
diagnosed
visual failures
and their
sources and
consequences
Information
concerning
the sorting of
the systems
for further
steps
Specific
information
resources
Test and
diagnosis
software
Specification
(e. g. input
signals, test
cases, set
output signals,
transmission
behavior)
Gained
information
Localized and
diagnosed
failures and
their sources
and
consequences
Information
concerning
the sorting of
the systems
for further
steps
Systems with not diagnosed failures
Direct Visual
Diagnosis Parameter
Estimation
Material flow
Systems with non- repairable failures
Systems with diagnosed failures
All systems
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47
4 Test and Diagnosis of Electronic Control Units in
Remanufacturing
4.1 Potential Methods for Remanufacturing
The following figure shows potential methods for the test and diagnosis of electronic control
units in remanufacturing.
Figure 7: Potential methods for the test and diagnosis of electronic control units.
The direct visual diagnosis can be used as an additional method. It is however not regarded
as an individual method, since it is not able to substitute the other ones. The reason for the
elimination of the stochastic signal methods is the extremely high amount of output signals
that would have to be evaluated for the failure detection. With regard to the model based
methods, only the function test and the artificial neuronal networks will be considered
further. In reference to the basic requirements, the methods fuzzy and neuro fuzzy models
are not economically feasible for electronic control units.
Potential methods for the test and diagnose of electronic control units
Signal Based Methods
Automatical Optic Diagnosis
Bed of Nails Test
Clip Test
Flying Probe Test
Manual Microscopic Diagnosis
X- Ray Diagnosis
Thermal Imaging
Behavioural Test
Model Based Methods
Function Test
Artificial Neuronal Networks
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48
Because of the main reasons mentioned below, the model based methods parameter
estimation, state extent estimation and parity space models will not either be considered:
Not enough knowledge is known in the field of electronic control units in remanufacturing
companies.
The effort to create a model of the unit is huge.
These methods are only suitable for small electronic control units (controlling only up to
40 parts), which is not given in automotive electronics.
Instead of the model based methods parameter estimation, state estimation and parity
space, the functional test is potential for the test and diagnosis of electronic control units in
remanufacturing.
4.2 Selection of Methods for Remanufacturing
Target of that chapter is to find out the best method or the best combination of methods for
the test and diagnosis of electronic control units in remanufacturing companies.
Remanufacturing companies are divided into independent (OE data are not available) and
OE manufacturer-related (OE data are available) companies.
4.2.1 For Independent Remanufacturing Companies (OE data are not
available)
The following table shows the result of an evaluation for the test and diagnosis of electronic
control units.
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49
0 5 6 7 10
Table 4: Result of an evaluation for electronic control units (for independent
remanufacturing companies)
System knowledge
Efforts for model creation
Transferability
Failure test
Failure diagnosis
Efforts for automatisation
Invest
Duration of test and diagnosis
Efficiency share
Effort for model creation
Efficiency share
Technical effort
Efficiency share
Economical effort
Efficiency
Main Criteria
Importance in %
40 30 30
Single criteria
Importance in %
37 23 40 40 60 20 43 37
Automatical Optical
Diagnosis 8,0 4,7 6,0 3,3 4,9 10 7,2 8,1 6,4 4,3 8,1 6,3
Bed of Nails Test 1,5 3,6 3,9 8,9 10 10 6,8 8,2 2,9 9,6 8,0 6,4
Clip-Test 1,5 5,0 5,7 8,9 10 2,0 8,7 0,9 4,0 9,6 4,5 5,8
Flying Probe Test 1,5 1,7 3,5 8,9 10 10 1,4 5,5 2,3 9,6 4,6 5,2
Manual Micros-
copic Diagnosis 8,5 8,3 9,1 3,1 3,7 0,0 9,3 1,3 8,7 3,5 4,5 5,9
X Ray Diagnosis 8,0 8,3 9,1 5,0 4,9 2,7 0,6 1,5 8,5 4,9 1,4 5,3
Thermal Imaging 7,8 7,9 9,1 7,7 8,9 8,3 7,0 7,5 8,3 8,4 7,4 8,1
Behavioural Test
8,0 7,0 6,7 9,9 4,9 10 8,2 6,2 7,3 6,9 7,8 7,3
Functional Test 1,5 1,5 3,4 9,9 6,3 10 7,1 8,2 2,3 7,7 8,1 5,7
Artificial Neuronal
Networks 8,5 4,7 5,3 9,9 4,6 8,0 7,0 6,9 6,3 6,7 7,2 6,7
The table above shows a summary of all calculated grades, as well as the efficiency shares
and efficiencies of all methods for the test and diagnosis of electronic control units. The
following figure shows the recommended process steps for the test and diagnosis of
electronic control units.
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50
Figure 8: Entrance and final test and diagnosis of electronic control units for independent remanufacturing
companies.
Testing and diagnosing of electronic control units:
Gained
information
Localized
and
diagnosed
failures
and their
sources
and conse-
quences
Informa-
tion
concerning
the sorting
of the
systems
for further
steps
Specific
information
resources
Test and
diagnosis
hard- and
software
Specifica-
tion (e. g.
connecting
technique,
tempe-
ratures and
their
allowed
tolerances)
Gained
information
Localized
and
diagnosed
functional
and struc-
tural fai-
lures, their
reasons
and effects
Information
concerning
the sorting
of the
systems for
further
steps
Specific
information
resources
Test and
diagnosis
software
Specifica-
tion (e. g.
input
signals,
test
cases, set
output
signals,
trans-
mission)
for independent remanufacturing companies
Beha-
vioural
Test
Direct Visual
Diagnosis
Thermal
Imaging
Specific
information
resources
Knowlede
of the
workers
Specifica-
tion (e. g.
pictures
of good
units,
main
failures
and
FMEA
results)
Gained
information
Localized,
diagnosed
visual and
structural
failure, their
sources
and conse-
quences
Information
concerning
the sorting
of the
systems for
further
steps
Systems with not diagnosed failures
Material flow
Systems with non-repairable failures
Systems with diagnosed failures
All systems
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51
0 5 6 7 10
4.2.2 OE Manufacturer-related Remanufacturing Companies (OE data
are available)
The following table shows the result of an evaluation of the potential methods for the test
and diagnosis of electronic control units for OE manufacturer-related remanufacturing
companies.
Table 5: Result of an evaluation for electronic control units (OE manufacturer-related
remanufacturing companies)
Table above shows a summary of all the calculated grades, as well as the efficiency shares
and efficiencies of all methods for the test and diagnosis of electronic control units.
The following figure shows the recommended process steps for the test and diagnosing of
electronic control units.
Failure test
Failure diagnosis
Efforts for
automatisation
Invest
Duration of test
and diagnosis
Efficiency share
Technical effort
Efficiency share
Economical effort
Efficiency
Main Criteria Importance in % 50 50
Single Criteria Importance in %
40 60 20 43 37
Automatical Optical Diagnosis 3,3 4,9 10 7,2 8,1 4,3 8,1 6,2
Bed of Nails Test 8,9 10 10 6,8 8,2 9,6 8,0 8,8
Clip Test 8,9 10 2,0 8,7 0,9 9,6 4,5 7,0
Flying Probe Test 8,9 10 10 1,4 5,5 9,6 4,6 7,1
Manual Microscopic Diagnosis
3,1 3,7 0,0 9,3 1,3 3,5 4,5 4,0
X- Ray Diagnosis 5,0 4,9 2,7 0,6 1,5 4,9 1,4 3,1
Thermal Imaging 7,7 8,9 8,3 7,0 7,5 8,4 7,4 7,9
Behavioural Test 9,9 4,9 10 8,2 6,2 6,9 7,8 7,4
Functional Test 9,9 6,3 10 7,1 8,2 7,7 8,1 7,9
Artificial Neuronal Networks 9,9 4,6 8,0 7,0 6,9 6,7 7,2 6,9
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Figure 9: Entrance and final test and diagnosis of electronic control units for OE Manufacturer-related
remanufacturing companies.
This process combination can be applied for every electronic control unit that is not sealed
with resin material or silicone and that can be opened without destruction. For some parts of
the electronic control unit, the thermal imaging can be used instead of the bed of nails test.
Testing and diagnosing of electronic control units: OE manufacturer-related remanufacturing companies
Specific
information
resources
Test software
Process model
of the unit
Detailed
specification
(e. g. exact set
parameters
and their
permitted
tolerances)
Gained information
Localized and
diagnosed
functional
failures and
their sources
and
consequences
Information
concerning the
sorting of the
systems for
further steps
Specific
information
resources
Test and
diagnosis
software and
hardware (bed
of nails tester)
Detailed
specification concerning
parts (e. g.
power input)
Gained
information
Localized and
diagnosed
structural and
functional
failures and
their sources a.
consequences
Information
concerning the
sorting of the
systems for
further steps
Systems with not diagnosed failures
Functional
Test Bed of Nails Test
Material flow
Systems with non-repairable failures
Systems with diagnosed failures
All systems
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5 Test and Diagnosis of Actuators and Sensors in
Remanufacturing
The actuators and sensors that are used within mechatronic systems and in vehicles are
nowadays either assembled as electro mechanic systems, as electric systems, electronic
systems or independent mechatronic systems. Lots of actuators and sensors are built in
todays vehicles. The failure rate in the following table refers to one operating year of the
sensor.
Table 6: Failure rates of vehicle sensors.
Sensor type Sensor application Failure rate
in %/year
Absolute Value Steering angle sensor 0,87
Induktive, Hall-Effect Wheel speed sensor 0,26
Incremental, Hall-Effect Steering wheel angle sensor 0,25
Hall-Effect Acceleration sensor 0,25
Piezoresistiv Break pressure sensor 0,043
Resistiv Throttle valve potentiometer 0,0036
Considering the table above as well as the fact that great amounts of sensors are used in
vehicles, sensors represent a significant failure source.
6 Remanufacturing of Electro Hydraulic Power Steering
Pumps
The reasons for the choice of this system are on the one hand to be found in the relatively
high failure rate and the elevated costs of brand new parts of the electro-hydraulic power
steering pumps (EHPS-pumps) and on the other hand in the feasibility of remanufacturing
the system. For the practical application an EHPS-pumps of the manufacturer TRW is being
used.
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6.1 Description of the System
Within the electro hydraulic power steering, the steering moment of the driver is decreased
with the help of an EHPS-pump and a rack steering. The following figure shows the
assembly of an electro hydraulic power steering unit of the manufacturer TRW.
Figure 10: Servo steering of the manufacturer TRW (source: TRW Automotive).
6.1.1 Functionality of the EHPS-pump
The following figure shows a sectional view of the electro hydraulic power steering pump of
the manufacturer TRW. In the following, this model will be referred to as TRW_2. The pump
uses steering oil from the tank (1) and, with the help of a cogwheel pump (2) it generates a
load dependent high pressure oil volume flow. The drive of the pump is affected by a
brushless dc motor (4) which is regulated by an electronic control unit (3). A torsion steered
valve (6) within the rack steering (5) lead the generated oil volume flow in such a way that it
supports the drivers steering decision via hydraulic barrels.
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Figure 11: Electro hydraulic power steering pump of the manufacturer TRW.
6.1.2 Functionality of the EHPS-Pump
The main components of the EHPS-pump are shown in the following figure.
Figure 12: Sectional view of an EHPS-pump of the manufacturer TRW.
(1) Tank
(2) Cogwheel pump
(3) Electronic control unit
(4) DC motor
(5) Rack steering
(6) Valve
(1) Oil tank with refill expansion tank cap
(2) Pressure control valve
(3) Electric connector
(4) Subassembly cogwheel pump
(5) Electronic control unit
(6) Hydraulic connectors
(7) Brushless dc motor
(8) Motorside aluminium case
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The dc motor (7) is coupled to the cogwheel pump (4). Once set into operation, the
cogwheel pump aspirates the servo steering oil of the oil tank (1) in order to pump it to the
hydraulic connectors (6). The pressure control valve (2) is in charge of the oil pressure
limitation. The inputs to the electronic control unit are the power supply from the battery and
the control voltage from the engine control unit. The three hall sensors that measure the
position and the engine speed of the rotor are integrated in the electronic control unit. With
the help of the external and internal data, the electronic control unit regulates the ramp up,
the operation and the shutdown of the pump.
6.2 Process Steps in Remanufacturing
The remanufacturing of the EHPS-pump is effected according to the six steps of
remanufacturing of mechatronic systems, namely the entrance test and diagnosis, the
disassembly, the cleaning, the test and diagnosis of the subassemblies and parts, the
reconditioning and the reassembly. The entrance test and diagnosis provides important
information about the condition of the system and the subassemblies and in some cases
even about the condition of some parts. Dependent on the result of the entrance test and
diagnosis, the EHPS-system can be remanufactured or has to be material recycled.
All EHPS-pumps are disassembled without destruction. Mechanic subassemblies, as the
cogwheel pump or the overpressure valve are disassembled into their parts. The electronic
control units are not disassembled. All the wear parts like ball bearings, oil filters etc. are
sorted out and passed on to a material recycling. The cleaning of all subassemblies and
parts represents the third step in remanufacturing. The test and diagnosis is carried out for
the electronic control units and parts.
After the test and diagnosis of the subassembly and the parts, the directly reusable
components are placed in storage, while the non-directly reusable components are
reconditioned. The recondition is based on the fixing of the detected, localized and
diagnosed failures. After the reconditioning the mechatronic systems are completely
reassembled. During this method, the wear parts are always replaced by new ones.
All steps of remanufacturing are constantly supervised by a quality controller. Before the
systems were sold, all the EHPS-pumps go through a 100 % final test and diagnosis. The
steps of disassembling, cleaning, reconditioning and reassembling are comparable to the
remanufacturing of mechanical systems.
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6.3 Entrance and Final Test and Diagnosis in Remanufacturing
6.3.1 Choice of Methods
The remanufacturing process consists of the selected methods mentioned above. With
regard to independent remanufacturing companies, the combination of the two signal based
methods, the direct optical diagnosis, and the characteristic curves, has presented itself as
the best solution. With regard to manufacturer-related remanufacturing companies the
parameter estimation has been preferred to the characteristic curves test, since it provides a
greater range of failures. The EHPS-pump can be regarded as black box and characterised
on the basis of its input and output signals. The following figure shows the relevant input and
output signals of the EHPS-pump.
Figure 13: EHPS-pump as black box system.
Based on the measured input and output signals, the characteristic curves reflecting the
function of the system, can be measured.
6.3.2 Construction of the Test Bench
Accomplishing the characteristic curves test, requires an automated industrial test bench,
which has to be developed, produced and put into operation. The following main tasks are
assigned to the test bench:
Simulation and control of the environmental conditions in order to enable every
operation point of the EHPS-pump.
ECU Voltage Input
Pump Voltage Input
Pump Current Input
Measurement
Oil Volume Flow
Pressure ECU Current Input
EHPS-Pump
as Black Box
System
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Measurement of the input signals and output signals of the EHPS-pump and the
environmental conditions.
Evaluation of the results.
The construction of the test bench is done with the computer aided design (CAD) program
Pro/ Engineer Wildfire. The following figure shows the CAD-model of the test bench.
Figure 14: Construction of the test bench for EHPS-pumps.
The required main components, as for example the power supply, the volume flow sensor,
the pressure sensors, the proportional control valve, the oil filling pump, the control and
measuring software are provided by suppliers. In order to simulate the environmental
conditions at the test bench, the oil volume flow is restricted by a proportional control valve.
The following figure shows the real construction of the industrial test bench for EHPS-
pumps.
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Figure 15: Industrial test bench for EHPS-pumps.
6.3.3 Running the Tests
The core pump is electrically and hydraulically adapted to the test bench. This adds up to a
clamping time of about 10 seconds per EHPS-pump. On the PC, the operator is able to
access to already existing test cycles and specifications of the data base, or they can define
new ones. Now the system is automatically filled with servo steering oil. By regulating the
proportional control valve, the test cycle moves the EHPS-pump into the defined operating
conditions. The hydraulic environmental conditions of the test bench simulate the real
EHPS-pump conditions in the vehicle.
With the help of the input and output signals, the test bench calculates operating points.
Those are then compared to the allowed specifications. The collected measured data are
saved for the quality assurance on the personal computer. The measured data are printed
automatically. This data offers important information for the further remanufacturing steps.
After the test has been completed, the servo steering oil is automatically pumped off the
core, so that the EHPS-pump can be removed from the test bench, which may take up to
another 10 seconds of unclamping time. A test that includes clamping and unclamping,
filling, measurement, evaluation and cleanout requires about 60 seconds time, depending
on the number of examined points.
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6.3.4 Test Bench Results
The determined characteristic points of the EHPS-pumps are interconnected to a
characteristic curve which serves as test result. The following figure shows the characteristic
curves (volume flow, input power, output power and efficiency through pressure) of a new
EHPS-pump of the manufacturer TRW.
Figure 16: Characteristic curves of a new EHPS-pump of the manufacturer TRW.
By slowly closing the control valve, the pressure of 4 bar (which corresponds to the minimal
loss of pressure within the system) arises to a maximum of 88 bar, which corresponds to the
maximum pressure of an EHPS-pump which is controlled by a responding internal limitation
valve. The characteristic curves of the EHPS-pumps can be divided into the following four
sections:
4 to 17 bar: waiting range with a constant volume flow, increasing input and output
power and intensely increasing efficiency.
18 to 28 bar: activating range with rising volume flow, rising input and output power and
nearly constant efficiency.
28 to 80 bar: working range with decreasing volume flow, increasing input and output
power and nearly constant efficiency.
Pressure in bar
Pressure in bar
Pressure in bar
Pressure in bar
Volume flow in 1/min
Input power in W
Efficiency in %
Output power in W
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80 to 88 bar: over pressure range with decreasing volume flow, decreasing output
power and efficiency and increasing input power.
After the activation of the input signals, twelve out of the 106 cores have not shown any
reaction. The following figure shows the calculated characteristic curves volume flow
through pressure of the 94 working EHPS-pumps.
Figure 17: Characteristic curves of 94 working EHPS-pumps.
Only one EHPS-pump clearly shows a less volume flow and a maximum pressure lowered
by 50%.
6.3.5 Determining the Specifications for Remanufacturing
EHPS-pump manufacturer specifications concerning the test and diagnosis are generally
not available. In order to determine specifications for the EHPS pumps, in-situ
measurements are carried out during various driving experiments.
Therefore, a new EHPS pump is installed in a test vehicle. In order to characterize the
EHPS pump during the driving experiments, the inputs and outputs have to be measured in
the same way compared with the test bench. Voltage sensors, power input, volume flow and
pressure sensors as well as the measured value acquisition that is carried out with the help
of a laptop with PCMCIA-card are also installed in the vehicle. Since the TRW_2 EHPS-
Volume stream in l/min
Compression in bar
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pump is mainly installed in the Opel Astra G, this vehicle type is the one used for the real
road tests. The tests are carried out on a test territory that is not accessible for the public.
The following figure shows the passenger compartment with the driver and the measured
value acquisition (left) and the test vehicle on the test territory (right).
Figure 18: In-situ measurements during driving experiments in order to determine specifications.
A total of 10,000 operating points within the different ranges of the EHPS-pumps are
examined. The following figure shows the calculated specifications for six operating points
(P1 too P6).
Table 7: Specifications for the EHPS-Pumpe (Type TRW_2).
P 1
(5bar)
P 2
(30bar)
P 3
(50bar)
P 4
(65bar)
P 5
(80bar)
P 6
(85bar)
Volume flowmin in l/min 3,8 3,8 3,8 3,75 3,3 0
Volume flowmax in l/min 5 5 4,75 4,25 3,75 3,6
Power Inputmin in W 20 320 540 620 680 680
Power Inputmax in W 100 420 600 700 760 760
Power Outputmin in W 30 190 320 410 440 0
Power Outputmax in W 45 250 400 460 500 500
Efficiencymin in