Category: Interviews

Ger Schoeber gives one of the most popular training courses at the High Tech Institute, in system architecture. He does this in addition to his full-time job as group leader and domain expert system engineering at Lightyear. Schoeber about the role, usefulness and pitfalls for the system architect.

Ger Schoeber attended a meeting of Gerrit Muller’s System Architecture Study Group of in 2002. Muller had set up a new training course based on his experience at ASML and Philips: Sysarch, short for ‘System architecting’. This five-day course had been running for a few years and was now so popular that Muller had asked, during the meeting, who would be interested in joining him as a teacher.

The question intrigued Schoeber. He had extensive experience in system development at High Tech Automation and Ordina and had not been working as a self-employed person for so long. ‘I was not at home standing on a podium and this gave me a great opportunity in which to stretch my comfort zone. When I received my baptism of fire in September 2002, I had the absolute impression that those sixteen participants actually had a lot more experience in system architecting than myself, ‘ Schoeber laughs.

Gerrit Muller received his PhD in system architecture during those years, a subject that was not taken very seriously in the academic world. His findings were often immediately translated into subjects for the training. After Muller’s promotion in 2004, Schoeber took over his method CAFCR (Customer Objectives, Application, Functional, Conceptual, Realization, pronounced as: kafkar). This framework grew into the core of the system architecting training in the years that followed. ‘I myself applied the CAFCR method as a system architect for the first time in practice in 2005. That gave me a lot of insight, value and experience,’ says Schoeber.

Above all, practical experience is valuable and Schoeber shares this with the participants in his courses, of whom there have been over a thousand. He has been involved for almost three decades in small and larger multidisciplinary projects at OEMs. Since 2011 he has been employed by Hotraco, an agri company where he fulfills the role of innovation and technology manager. ‘In recent years I have been able to apply Sysarch theory in practice. It has given a lot of value to my own projects and provided direct experiences with the application of the material, something that I have been able to use once again as examples in the training courses.’

Putting yourself into the client’s shoes seems natural, but it is the most difficult thing of all, says Ger Schoeber.

Thinking business-like

The system architect is responsible for the technical realization of a product or subsystem. System architects always have many years of development experience. Both this background and technical baggage are indispensable. But system architects must have social skills in order to fulfill their role, because they are in contact with all stakeholders. Not only with the people in the development team and suppliers, but also with the management team, investors, customers and end users.

Schoeber sporadically sees non-motivated course participants. These are often technicians who have been sent on the course by their boss. Schoeber considers them unsuitable for a role as a system architect. ‘System architects are proactive and must take the lead in technical development. They are motivated by definition, want to be at the forefront. They also have a vision: that’s what it is all about. They must also radiate their faith and trust in it.’

This has consequences for the way that system architects work within an organization. They have to be strong and confident and dare to say no. ‘If they do not have enough confidence in the successful completion of a project, they should not accept the assignment. Actually they should immediately say: I’m not going to do this. Because if system architects don’t trust it, the people in their team pick up on that immediately. They radiate it, non-verbally.’

Assessing whether a project can succeed or not, whether something is technically feasible and can lead to commercial success or not, is part of the task of a system architect. Schoeber: ‘The challenge often lies in the latter. Technically, something can be a fun job, but does it also have value for the customer and for the business? We also emphasize the last two steps in the training course. System architects need to think beyond just the fantastic technical aspect. It must also be right for a customer. That means that they have to be able to think from a customer’s point of view.’

In addition to having empathy, system architects should not lose sight of the value of the project for the business. ‘You can make something fantastic and make the customer very happy by offering it for nothing, but then it has no business value. So thinking business-like is also important for the system architect. ‘

What are the biggest pitfalls for system architects?

‘That they do not stand up enough for their team and say: I’m confident that this will work out. Because if you do not have that feeling yourself, then it will not work. An even bigger challenge is thinking from the customer’s point of view. I often say that you do not just have to make what the customer asks for, but to make what the customer needs. I ask the question: try to stand on the other side. Change places. What end result would you like to have as a customer? What do you need help with? If you need to create a subsystem that will be integrated into a larger whole, then imagine yourself as the party that needs to integrate that piece. What is it then that you need help with? Is there something extra that makes integration or verification easier? If you start thinking from that position, you discover that you have to do more than simply perform what is in the requirements.’

Why is putting yourself in someone else’s shoes so difficult? It sounds so easy?

“That’s the hardest thing. Not everyone has sufficient empathic ability. Empathy is perhaps even more difficult for men. Women can experience emotion better and put themselves in someone else’s position. For that you also have to dare to be vulnerable. Men are more macho: look what I made. It would be nice if more women took on the role of system architect.

So it’s nothing for the diehard technician who wants to be technically excellent?

‘No, technicians should never want to become system architects. They should, above all, continue to do what they like doing: being active with their technique and being a specialist in that. Technicians can be very good at thinking of solutions, but in order to make a commercially successful product, you also have to ask what the problem is. That means you have to be able to inquire: why do you really want this? With this you penetrate deeper into the real need. Because a customer, also one of the stakeholders, often thinks of the solution, instead of trying to explain what their problem is. ‘

In collaboration with Incose-NL (International Council on Systems Engineering) and the high-tech magazines Bits & Chips and Mechatronica & Machinebouw, the High Tech Institute recently organized the Dutch System Architecting conference. Schoeber was Chairman.

Is that the customer’s pitfall?

‘The customer has often devised a solution direction himself. It is tempting for the system architect to follow their lead: Oh yes, we have to do that! Instead, you have to counteract that and say: Why do you want this and why do you want to solve it that way? This is precisely where the CAFCR model devised by Gerrit Muller helps.

What does CAFCR mean?

‘It’s all about moving into the customer’s shoes. In doing so, you look at system architecture from five viewpoints. Only two of them are about technology, about the solution. For example, the C of ‘conceptual view’ says: I want to communicate wirelessly. That is more general than the R of ‘realization view’, which is about the technology that is needed to reach the solution, for example bluetooth, wifi or zigbee. ‘

‘The other three are about the customer’s perspective. In my opinion, that is where the greatest value of the CAFCR framework lies. The F of the functional view is about the specification, the requirements: What does the customer expect from the product or what do the stakeholders expect in functionality, quality and performance? The A of ‘application view’ requires that you look at the broader context. In which environment does the subsystem or system come? How is it applied? If you have a good idea of ​​that, then you also understand what is useful or not. That enables you to improve the requirements. ‘

‘The first C of customer objectives’ is all about the customer: What exactly is their business? How do they earn their money? What is the living environment of the customer or the colleague who is going to install my subsystem? If you understand that better, you will see better what it is that they need in order to do better business. CAFCR forces me to look not only at the technology, but also at the specification and the rationale of the requirements. It allows me to come up with solutions that help customers even more.’

As an example, Schoeber refers to Gerrit Muller, who experienced the development of a new generation of radiological equipment at Philips Medical in the late nineties. At that time the medical world sat in the middle of the transition from analogue to digital. At Philips they had designed a beautiful system that radiologists and other specialists could use to assess everything on high-resolution screens. The Philips technicians only discovered at a late stage that this did not match the practice. Radiologists hung photographs in a light box and if they had some time in between, they grabbed their dictaphone and whilst walking they discussed the diagnosis and treatment.

Schoeber: ‘Muller showed that it is useful to walk with a radiologist to see how they spend their day. That print function was not in the original design, it was added later. The lesson is that you have to empathize with the customer’s experience at an early stage.’

Schoeber therefore advises system architects to spend a day with customers to discover what they really need. ‘Océ does that too. They parachute their technicians into a customer environment to experience how they work with copiers and printers. They take that knowledge back to the organization.’

‘I also force myself to be in a chicken or pig house regularly or work with the installer of our items. This gives me plenty of ideas about handy adjustments or better working methods. In the nineties, during a project for patient monitoring systems, I once put on a green jacket with a green cap and I sat in on four operations in a hospital. I saw what an anesthetist did with a patient monitor in an environment with blood and stress. Only then did I see what was really needed in an operation and the necessary functionality required. I could not have thought of that behind a desk. You understand the priorities only when you go with the customer and spend a day with them.’

Does the product manager also have to know that?

“Yes, they should know that. The system architect hears from the product manager what is needed and must translate that into a specification that a multidisciplinary engineering team can then carry out under their management. But if an architect only hears it and never experiences it, then they miss that emotion. Moreover, the product manager is often outside the company, not in-house. So the system architect has to go to the customer every now and then.’

Isn’t it a waste of time?

‘The time is immediately recovered. I once had the opportunity to supervise an architect at Vanderlande. He started looking at the commissioning of a baggage handling system. So-called commissioning engineers work there. He saw that those installers had come up with a workaround. They wriggled around corners, but did not recognize it as a problem anymore because they were used to it. “Oh, can it be different?” They reacted amazed when they heard from the architect that he could incorporate a function in the system that would save their work. You could send a survey to all those engineers, but you would probably get a lot more useful information by just spending a day with them.’

It is also a skill to transfer the knowledge to the team. When Schoeber worked at a high-end remote control at Philips, he commissioned a team member to learn all the infrared protocols. The technician proudly returned with the result: his prototype could, in addition to signals for the video recorder and TV, also imitate the infrared of fluorescent tubes and the sun. ‘So my colleague had taken me literally, because the remote control had to filter out the infrared signals in the ambient light.’

How do you learn to transfer the knowledge well?

‘It is not a matter of writing down specifications as good as possible and sending them to your engineering team. You must continue to explain it and repeat it over and over again. The human brain just doesn’t work like a computer memory. System architects cannot hide behind a statement like: “But didn’t I say that anyway?” You have to explain the same thing over and over again, keep on repeating it, otherwise it will not be registered.’

‘It is not just about technical details, but also about the strategy and vision of the project. What is the goal we want to achieve? What is the end point? That must be clear. The endpoint is something that works as specified and that is reliable, but there is also a deadline. If you want to introduce a product at a market event, then that is the strict deadline. Then you sometimes have to take a shortcut to get it done.”

In the end, balance is the great magic word for the architect, says Schoeber. ‘You can think of the best architecture, apply the best technology, but if the development takes too long, you have no business and salaries cannot be paid. The architect is in the middle of that game. Their own engineers want to make the best product, but it shouldn’t be gold plated. The customer ultimately has to get value for their money. They pay. The architect must also ensure that there is lasting business. Think of production, easy maintenance and future generations. Taking into account all those interests and stakeholders, something has to be created.’

This article is written by René Raaijmakers, tech editor of Bits&Chips.

Jasper Nuyens stepped somewhat eagerly through information technology. He was the first Aibo owner in Belgium and programmed his own Tesla. The biggest embedded Linux problems land on his lap.

Jasper Nuyens with an OpenSource BeagleBone board that participants use in his embedded Linux training and a hug from Tux, the Linux penguin.

Linux & Tesla

It is Elon Musks’ biggest nightmare that hackers worldwide take control of all Teslas remotely. ‘A doom scenario, but it is not impossible,’ says Jasper Nuyens, founder of Linux Belgium and embedded Linux trainer at the High Tech Institute. One key to gain access to one of the computer systems – the so-called ssh-key of the navigation cluster – is the same for the entire Tesla fleet.

Nuyens knows, because ‘through a friend’ he has secured such a ssh-key (‘ssh’ stands for ‘secure shell’, the standard for communicating with Linux systems). Not to harass Musk, but to reprogram his own Tesla. These cars have different embedded subsystems: Nvidia Tegra-based electronics around the wheel and the media console and ARM64 for the autopilot. It all runs on Linux. Nuyens, among others, adapted his control panel himself. ‘A little customised,’ he laughs. ‘With an X Window application, for example, I make the colours fade.’

Nuyens has a tip for Musk: if you want to sleep peacefully at night, it might be better to give all systems of all Teslas their own ssh-key and store them in a secure central database. This is already happening with a daily changing key for remote access to the central display. ‘An extra layer of safety, why not? It is still true that everyone has the same ssh-key on the navigation cluster and in principle you can obtain them online.’

However, it’s not easy to get into a Tesla. A physical connection with the internal network is required and the dashboard must be open for this. “It is very well shielded,” says Nuyens. Yet his skill with Linux is not the main reason that he has bought one. ‘The decisive argument came to me when I saw the retreated glaciers in Iceland.’

He does not touch the Linux-based system for autopilot. ‘I do not want to do anything wrong with regard to the control of my car. It is possible, people do it, but I, personally, find it a bit too dangerous. That is why I do not play much with the CAN-bus. However, I would like to make another variant of Tesla’s Christmas light show. I already have the Game of Thrones tune ready for it.’

Robot woof

Nuyens acquired a Macintosh computer at the age of nine and founded a computer club a few years later. Not many years later later, he started publishing articles about computers. And then also about Linux. He even authored, in 1996, the books ‘The Internet in Belgium’ and ‘Maximise your Mac’. For the first time, he wrote a review for every Belgian website. ‘There were only a few hundred.’

Nuyens tasted mathematics, physics and computer science at KU Leuven and Hasselt Universities, but did not complete his studies. ‘When I started at university at the age of sixteen, I saw many Internet Service Providers start up. Netvision/Ubizen (now owned by Verizon, RR) also started. I missed that first boat, but I really wanted to grab the internet boom.’ So he stopped studying in 1998 to start his own company at the age of 21.

Two years later, before the dotcom bubble burst, Nuyens sold his business to the NASDAQ listed VA Linux Systems, the company behind Sourceforge and the websites Linux.com, Slashdot and Freshmeat. That was fairly independent at the age of 23. He then set up Linux Belgium and bought the Aibo robotic dog from Sony. He was the first in his country and even in TV programs he was invited to talk about his robot woof. Newspapers wrote hilarious pieces at that time about ‘the young manager with a Saab Cabrio under his rear’ (Het Belang van Limburg).

With Linux Belgium, he focuses on consultancy and training. ‘I’m lucky that they ask me for advice when there are really difficult problems. This ensures that we always receive very special cases and that makes the job very interesting. It also ensures that our course stays up-to-date.’

Although he is no blind follower, Nuyens is very positive about Linux. ‘It is one of the most impressive technical achievements of our century,’ he writes on his Linux Belgium website. ‘More than a billion mobile phones run on Linux-based Android. All known servers work with it. In addition, billions of smart devices have the operating system on board and tens of millions of people use the OS on their PC. Google, Facebook and Twitter, they all run on Linux. ‘

1,4 MB floppy disk

In 2005, Nuyens developed the ‘Embedded Linux’ training course in collaboration with Mind (now Essensium). It turned out to be the very first embedded Linux course in the world. ‘We did it at the request of a customer. Developing a new course for embedded Linux was a lot of work, but we did it anyway.’ To the great surprise of Nuyens and Mind, the training became very popular. ‘In the field of Linux, it is one of the most popular courses in Belgium’, Nuyens estimates. High Tech Institute has been offering the training in the Netherlands for a number of years on an exclusive basis.

‘In the late nineties there was a lot of buzz around Linux for servers. The operating system is still popular for that, but to keep track with the growth of Linux servers, you need far fewer extra system administrators than in the embedded world, where the number of Linux applications explodes, and they all need developers’ explains Nuyens as its success.

The Linux pioneer already worked on a project in 1996, to run a complete Linux-based router from a 1.4 MB floppy disk. ‘This was done in order to use old PCs with a number of network cards as a server or router. It was a big challenge in which the Linux kernel compilation played a very important part. The tricks we had to pull out of our sleeves to make this work were a lot like the first steps of embedded Linux: a small system where you can add many applications.’ The project lives on in current router projects such as OpenWRT and DD-WRT.

Much later, the embedded build systems Buildroot and Openembedded/Yocto became available. ‘We also included that in our training. We always adjust the material to recent developments. We did about a hundred sessions, whilst we are on version 65 of the course.’

Beaglebone Black

In his Embedded Linux training, participants start working with a Beaglebone Black platform. This is a print with a Sitara SOC from Texas Instruments. This American chip manufacturer founded the non-profit organisation Beaglebone Foundation to provide Linux support for these platforms. ‘It is primarily a showcase for the Sitara platform,’ says Nuyens. ‘But it also gives developers a handy step forwards. Everyone can play around with the technology for free. ‘The entire Beaglebone design, the complete PCB layout with all its variants, can be completely reused by customers. By making minor changes to the copied reference design, you can speed up the roll-out of new products.’

If desired, Nuyens also has other variants of the course available. It is also possible to run the training on Freescale’s i.MX 6 platform (nowadays NXP). ‘This is also a popular platform in the Linux world. i.MX has single, double and quad core variants. The latter are more powerful for multimedia applications.’ Other variants on which the embedded Linux training can take place are the ZedBoards from Avnet and Atmel’s AVR32 platform. Training on these boards usually happens on specific request and often in-house at customers.

This article was published earlier in the magazine Bits&Chips: read it here.

This article is written by René Raaijmakers, tech editor of Bits&Chips.

Applying iterative learning control can improve the performance of motion systems tremendously. Often, by as much as ten-fold. However, the approach is fundamentally different to that of existing feedback and feedforward techniques. In order for it to be implemented correctly, a thorough understanding of the underlying learning mechanisms is required. The Advanced feedforward & learning control training provides the tools with which control technologists can understand and apply iterative learning control techniques.

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Photo: Tom Oomen, with the steering mechanism of a desktop printer that, despite numerous limitations, has reached an astonishing level of performance due to an iterative learning controller.

Control experts in the industry are also looking at this, says Tom Oomen, from the Control Systems Technology group (TU Eindhoven). He shows us the steering mechanism of a desktop printer that has been converted by a lab assistant into an experimental setup. ‘This is a simple arrangement costing roughly one hundred euros, with a lot of friction and cheap mechanics,’ says Oomen. ‘But despite these limitations, we can still achieve perfect performance with iterative learning control. The measuring accuracy of the printhead is 42 micrometres and with our learning management we stay within that limit.’ He can hardly suppress his enthusiasm: ‘That’s just amazing. Motion control experts also wonder how this can be achieved. Participants in the Advanced feedforward control course will also work with the same printer.’

The Control Systems Technology section, headed by Maarten Steinbuch, at the Technical University of Eindhoven has a long tradition of working with high tech companies. Researchers are working with ASML, CCM, NXP, Océ, Philips Innovation Services and Philips Healthcare on control through iterative learning control. The High Tech Systems Center (HTSC) also plays a role in this. The high tech companies implement and validate the developed algorithms directly on their systems.

Oomen: ‘They all really want to apply iterative learning control, because that’s the way to significantly improve performance. One company wants to achieve nanometer accuracy, the other higher productivity or to employ cheap sensors, actuators or mechanics. Because qua implementation, learning control is very cheap. The solution shifts from expensive measuring instruments and drives to software and smart algorithms. Our starting point is that measurement data are very cheap and that we can full compensate for what is reproducible in the measurement data.’

Back to basics. Everyone in the control world of the PID-controllers knows about feedback. Feedback generates a correcting action based on a servo error. It is a correction made subsequent to the error. PID controllers are popular because the system is in a ‘closed loop’ and is thus insensitive to changes. Another plus is that developers can work very intuitively with the help of rules of thumb.

The performance of these traditional control systems can be improved considerably by adding feedforward technology. Feedback control is, after all, like shutting the stable door after the horse has bolted: the corrective action follows the error. With the feedforward method the system anticipates future disturbances. If the trajectory is known immediately beforehand, the controller can use this knowledge to significantly reduce the tracking errors. ‘That typically leads to a performance that is ten times better,’ says Tom Oomen. Therefore, it is not surprising that now almost everyone uses feedforward.

But we can top that. By using the repetitive character with which many mechatronic systems work, control systems are able to learn from previous tracking errors. The result is another step forward in performance. Oomen: ‘Compared to traditional combined feedback-feedforward designs, the tracking error can be improved by a factor of ten or more.’ This is the basic idea behind Iterative Learning Control (ILC), with repetitive movements.

Design techniques in the High Tech industry

Learning techniques are central to the three-day Advanced feedforward & learning control training, of which Tom Oomen is one of the trainers and course leaders. ‘On the first day we start with PID controllers and we teach participants why you can only achieve limited performance. Feedforward makes more of a difference, because you give the desired task to your controller and thus look into the future. The idea of ​​learning control is simple: every time you do the same task, you know what will happen in the future. With a good learning control implementation, you can achieve perfect performance. That is also what people in my field say: everything that is reproducible can be perfectly compensated for.’

Photo: Tom Oomen, trainer and course leader of the Advanced feedforward & learning control training course.

Iterative learning control ensures that performance improves step by step. With every experiment, every cycle, the system collects measurement data which is subsequently examined by the learning controller: have I done it better now? If it is perfect, the controller will retain the feedforward control signal. If there is still a fault, a small correction will follow, in order to achieve an even better feedforward control signal. With a good design you see an almost perfect performance after five iterations.’

The methods used in the Advanced feedforward & learning control training course fit in very well with the design techniques already known by the Dutch high tech industry. They make it possible to converge motion systems with learning very quickly. Oomen: ‘That is really different to the rest of the world. You see a lot of academic techniques that need hundreds or thousands of iterations in order to converge.’

The unique Eindhoven approach is based on very accurate models for mechatronic systems. Oomen: ‘The basis for this was laid out in the seventies, eighties and nineties at the Philips Natlab, for example in the development of the compact disc players.’ Things that result from this, such as frequency-response-function identification, loop-shaping of PID controllers, and notch-filters, are now to be found in the basic course Motion Control Tuning. Oomen: ‘In the follow-up training, Advanced feedforward control, we construct the learning control technique from the same philosophy from the very beginning, so that from day one, the participants themselves are able to design and implement a learning controller which gives an almost perfect performance after a few iterations.’

Theory
The second day of training contains a lot of theory. The aim is to give participants a complete picture of what is available in the world in the field of learning control. Oomen: ‘Surf the internet for learning control and you will find mountains of information. Many different types of mathematics, usually from a strong academic perspective. Curious technologists automatically ask themselves: Why don’t we apply this?’

There is a world of difference between the alternative mathematical descriptions and the techniques presented to students on the first day. Why then all that hard work? ‘We expressly want students to experience how alternative methods work together in a mathematical way,’ says Oomen. ‘That is indeed quite difficult for most students, because they often have to refresh their underlying mathematical knowledge. Nevertheless, we confront them with it and drag them through the methods consciously, so that they can understand these other approaches and are able to put them into practice.’

Worldwide publications about control techniques always speak of optimal design algorithms. ‘Almost everyone in our profession is working on this,’ says Oomen. ‘That is certainly in line with the criteria they set. We are also going to work on it. Participants in our course experience a lot of parameters that are relevant. Our experience is that understanding all these parameters and how they influence performance is complicated. By letting these participants experience it for themselves, they gain all the knowledge needed to assess what it is that specific algorithms can or cannot do together with their respective advantages and disadvantages. This gives participants the feeling that they can oversee the entire field of iterative learning control. Especially if they want to delve into it more deeply.’

You say that you have to drag participants through the theory and mathematics. Does that always work?
That always works. And once you’ve seen that, you can pretty well see the range of techniques that are available. It is not about reproducing formulas, participants need to know what is behind them, what the basic ideas are and how they can use them. Once they have done this part of the course, the rest is really easy. It’s quite something that they are able to implement Matlab code in two lines. But the most important thing is that participants can substantiate the advantages and disadvantages of specific techniques. It is also nice to have useful knowledge to bring to day three, where we examine recent developments and use automated feedforward tuning.’

How much experience in control technology do participants need to be able to do the Advanced feedforward control training?
‘People with experience in designing controllers and motion systems automatically qualify for this training. This applies to most people who design feedback controllers in the Eindhoven region. They know how to design PID controllers and also what state-space, loop-shaping and filtering techniques are and how to think in the frequency domain. A little Matlab knowledge is also very useful.’

‘The basic knowledge needed is in fact the basic training to be found in the Motion Control Tuning course. The description gives a clear picture of the expected prior knowledge. People may therefore draw the conclusion that they should first follow the Motion Control Tuning training course.’

Can you give some examples of the type of participants in the Advanced feedforward control training sessions?
‘Participants vary from young people who have just left the lecture rooms, to motion control tuning experts who have been working in the industry for twenty years and who design controllers every day. For example, motion control experts from ASML, K&S, Nexperia Itec or Océ who are not yet familiar with iterative learning control. And also, technologists who have already experimented with this new technique in their work and who are interested in it. Among them are many small companies that want to apply iterative learning control. After three days they get a sense of what it can offer for their machine and also, right away, a basic implementation so that they can directly get started on their own machines.’

Before, with regard to the number of iterations, you mentioned five cycles. Does it matter if there are a few more or a few less?
‘The great thing about learning algorithms is that they adapt themselves when the situation changes. If temperature plays a role, for example because of a day-night rhythm, it is nice if the system adjusts within a few iterations. If, for example, 100 iterations, of one hour each, are required, this can lead to production failure.’

Oomen gives another extreme example. In collaboration with the researchers from the Eindhoven research institute Differ, the motion control group applied learning techniques to nuclear fusion experiments for the Tokamak reactor (TCV) in Lausanne. ‘Physicists have traditionally relied on complex physical models to simulate these fusion processes. There is a big gap between the use of data and control technology. My colleague Federico Felici has expertise in nuclear fusion, in addition to a background in iterative learning control technology. He is now dabbling in that world from his technical background.’

In Tokamak reactor experiments it comes down to plasma formation by means of the correct actuator signals. Such a shot takes a few seconds and is very expensive. ‘Because a complex computer simulator had already been developed, we were able to calculate how to adjust the signal to make it better. To do this, we linked the simulator to the measurement data from the experiments. It turned out that with our iterative learning control technology we had an almost perfect control signal within a number of iterations. That has had a lot of impact in the nuclear fusion world.’

 This article is written by René Raaijmakers, tech editor of Bits&Chips.

High temperatures lower not only the lifetime but also the performance of many electronics. A clever, cost-effective thermal design translates into a commercial advantage. ‘Your competitive edge increases  if you can deliver performance at lower costs or offer more performance at the same price through better cooling’, says Wendy Luiten, who delivers the Electronics cooling thermal design training.

High Temperature impacts the performance of everything that depends on computing power or memory. It is also an important factor for the performance of image sensors and energy converters, lamps and power supplies.
One of the difficulties in thermal design is that key decisions often go unnoticed. Says Luiten: ‘If you want to do it low cost, many critical cooling parts are not directly visible. They do not show up on your Bill of Materials. That makes it tricky. Passive fan-less air cooling is a preferred low-cost cooling solution, but air is not on your BOM. Neither are the open spaces that accommodate air flow. So, if a mechanical designer incorporates an open space as an air path in the design, it is not registered anywhere by default as a cooling component. That means that at a later time in the design process changes can be made that disable the original cooling concept. It is just not in the documentation, if you don’t put it in specifically.’

Don’t design tools to take this into account?
‘No, not really. Thermal behaviour is the combined result of electronical and mechanical design and the effect of a change on cooling performance will show up in CFD (Computational Fluid Dynamics) Thermal simulations that combine the inputs of both. But it will not show up in stand-alone Electrical and Mechanical design tools. You often see in product development that a thermal simulation is ran based on the finalized mechanical CAD and electronical layout EDA files, but essentially then what you have done is replacing the hardware prototype with a CFD simulation, after the detailed mechanical and electronical implementation has been finished. If the thermal simulation shows a problem with temperature, part of the mechanical or electronical design process has to be re-done. Obviously, that is a waste that you want to avoid.’

How does your training offer a handle on this?
‘We teach a way of working as well as the physics. Thermal design needs to be taken into account starting in the architectural phase and thermal risks addressed pro-actively. If you think the IC might need a heatsink, address the issue and ask the layout to put in heatsink mounting holes.  Do not wait until the complete lay-out is finished and you can do a test.  If layout has just completed a complicated multi- layer board, and part of it has to be re-done in order to accommodate the mounting holes for the heatsink, people are not going to be happy’. ‘So, if you think there is a risk, ask for the holes.  Maybe they are not needed after all, but unused holes in the PCB are no big deal. The other way around carries a much larger project risk: if you do need the heatsink but the holes are not included, the layout will need to be party re-done, and that can cause a development time delay’. ‘With a good thermal design, a lot is possible, but you have to make sure that the thermal concept is sound from the beginning of development to avoid re-designs.’

High temperatures have a negative influence on the life expectancy and reliability of components. Therefore, some chip manufacturers integrate temperature control software in their IC’s. Intel started by incorporating a thermal sensor in its P6-processors that simply shut them down if they heated up too much. Intel’s Pentium 4, Xeon and Pentium M processors had an additional over-temperature protection that slowed down the IC’s clock speed if it got too hot.

But temperature safeguards don’t automatically have a positive influence on the thermal behavior, indicates Luiten. ‘Many people think that using an IC with temperature protection solves the thermal problem, but this is not the case. The safeguard does not cool the IC but typically lowers its energy consumption by lowering the performance.  If the products thermal design is weak at system level the component will get hot sooner and more often and the end performance at system level will be jeopardised.’

Luiten found this out first-hand in a recent consultancy job on an image processing device. As soon as the video processor became too hot, the display went black. ‘It turned out to be an intended feature, not a bug. The video processor had embedded memory that was susceptible to high temperatures so the component supplier had added a temperature protection. As soon as the internal temperature sensor experienced over-temperature, the thermal protection kicked in. Normally this would not have been a problem, but in this case the product was developed for use at higher temperatures so the black screen was an unpleasant surprise.’

Because of this components temperature protection, the thermal design of the product became more critical. ‘If the IC’s temperature went up too high, it switched off. So, the protection seemed like a clever thing to do at component level, but at the same time it made thermal design more critical at the system level. In the end a partial re-design was needed to make sure the product worked way as intended.’

What is the most important topic in the training?
‘Thermal problem solving and better cooling design. Heat is a major performance-limiter in many electronic systems, from computers to lighting. The moment you can cool your product better at the same price point, this translates to better performance at the same price and this is a commercial advantage.’

Where do attendees work?
‘We have people attending from all levels in the system design, from component to module to complete system. Many former attendees worked on components, small electronic products and LED applications, but we have also had people working on large systems, like radar systems or heat sinks in large power supplies and we have had people from cooling component suppliers. With the increase in automotive electronics we also see more people coming in from that field.’

What makes people sign up?
‘Part of them come by word of mouth. Clemens Lasance and myself are both known in the international electronics cooling community and so is this thermal training.  The training is in English and draws an international public. We have had people coming in from as far as the United States that had heard they had to go to Eindhoven in order to get a really good thermal training.’

What makes the training special?
‘Clemens and I really teach electronics cooling in an application-oriented way. The training covers all aspects and is very hands on: we go from high level system architecture to implementation level details such as layout and locations and dimensions of air vents. And this is backed up with physics and best practices.

You don’t learn how to swim by just looking at other swimmers. Our goal is to send participants home with applicable skills, and that includes the hands-on ability to do basic calculations.’

‘I want people to get a sense of sizing, to get a gut feeling for thermal estimations.  If you have this ability, you will be able to take much better design decisions and you will also be much more confident in doing thermal simulations because you better know what is happening.’

Can you bring your own case study?
‘We always ask participants beforehand if they have a case of their own to share. If applicable, we will discuss it during the training. This is fun, because it leads to lively discussions. In addition, we have some standard cases.’

During the training: learn to thermally interpret specifications

Lasance and Luiten discuss the physics of electronics cooling, how to benefit from best practice thermal ways of working and how to implement them during the product development phases. This also explains why time management and project management are part of the course. ‘We discuss specifications and the way to interpret them thermally as well. We have people from system, sub-system and component level – this leads to interesting discussions on the interpretation of specifications.’ ‘The last learning activity of the course is a case study.  We split the group into two teams and spend two to three hours to crack a case. This is an eye opener to many people because it is the first time that they take the factors and specifications at all levels into account and see for the first time how mechanical and electronic considerations interact into the thermal behavior from component to system.’

When you have finished the training…
‘You have applicable skills on estimating thermal effects that you can use to estimate how to cool a product properly. Many participants indicate that this is the unique selling point of our training. Both people that are new to the field and experienced thermal architects and designers comment on how much they have learned during our course and recommend it to their colleagues. In addition, the know-how increases confidence in your results if you happen to do thermal simulations because you better know what you are doing.’

What people attend?
‘Attendees typically have higher education in a technical field such as electronic engineering, mechanical engineering, physics, optics, or industrial design. We often see product developers and architects with a couple of years development experience get into the thermal discipline. In Europe we have no higher professional education or academic education in this field. The United States do have universities that offer cooling of electronics courses, but they have a more academic approach.

Do you update the course regularly?
‘Absolutely. Recently we decided to split the training and you can choose either to go more in-depth with Clemens Lasance or do more hands-on exercises with me. That change was well received. At the moment, I am working on Design for 6-sigma and thermal design. In the thermal architectural phase, you already have to check how mechanics and electronics work together, identify the demands on the thermal behavior and design, optimize and verify how to make it work out. This combines well because of the system level approach in DfSS. And you can get great results in design and optimize phase with the combination of computer CFD simulations and Design of Experiments.’

Photo by: Bart van Overbeeke

Wendy Luiten started her career halfway the 80s as a thermal specialist at the Philips Centre for Fabrication techniques, at that time just split from the well-known Philips Research Laboratory (Natlab). In the late nineties, she contributed as a thermal architect in the development team to the first flat-screen televisions, made by Philips Consumer Electronics. ‘These early plasma screens had fans on board, and the fan noise was not liked so the challenge was to take them out.’ Luiten wrote a paper on the thermal design of the first plasma TV in the world without fans. This won her the best paper award on the Semi-Therm conference.

Cooling of electronics in consumer TV at first was seen as a temporary phenomenon. Managers assumed that existing heat problems would not be there forever. In reality, whenever a generation of televisions had outgrown its heat problems, product managers would pile on new demands on the development teams, going from plasma to LCD screens, the rise of HD TV, LED TV, 3D TV and smart-TV.

‘Every new generation would have its heat problems’, Luiten says. She ended up working sixteen years on a temporary problem. She is laughing about it. ‘I have done a temporary, non-structural activity for sixteen years straight.’

Since 2000, Luiten teaches courses Cooling of electronics. She has been all over the world for this, travelling to China, Singapore, Taiwan, Korea, the United States and several countries in Europe. Luiten also has been teaching in Saudi Arabia, at a summer school in Turkey and last year she presented the pre-conference short course Fundamentals of thermal system design at the European Therminic conference.

Together with Clemens Lasance, Luiten has been teaching the workshop Thermal design and cooling of electronics for fifteen years. This particular training has been split up into two modules and is being held online and Eindhoven, but the two of them were also presenting a pre-conference short course at the Semi-Therm conference in the United States. The combination of Luiten’s years of electronic product development experience and Lasance’s broad and deep knowledge of their discipline works particularly well. This marks their training as distinctly different from other available courses around the world.

Luiten is passionate about her subject, because she loves solving puzzles. ‘Designing the right cooling architecture for a range of TV’s forming a certain generation is similar to high-level puzzling. Together with the electrical and mechanical architect, you have to cover as many models as you can with the smallest set of different components. You need a flexible and scalable cooling strategy to cover the product diversity at acceptable cost.’

Nowadays Luiten is principal of her own firm: Wendy Luiten consultancy. ‘Not quite an original name, but highly practical.’

Getting the thermal design right for the Internet of Things

Thermal aspects are only part of the total problem, but Luiten expects the significance to continue. ‘Electronics cooling is important in the energy transition. Converting solar and wind energy to the grid requires power electronics, and this has thermal limitations. In addition, the materials that convert light to electricity and vice versa also are known to be temperature sensitive.’ ‘The transition to electrical and self-driving cars is also a hot item. Currently electronics make up 30 percent of the total costs for a car, and that is rising.’

Says Luiten: ‘Automotive electronics can be safety critical, failure for thermal or other reasons is not acceptable.’

Meanwhile in data communication, cooling is a well know cost issue ‘Data center cooling can cost as much as processing data, and in telecom 5G is expected to be a thermal challenge as well. For the Internet of Things also, getting the thermal design right is important. In future, there will be sensors everywhere.’

Partnership High Tech Institute

The training Cooling of Electronics is part of the T2Prof portfolio. T2Prof has continued the technical trainings on electronics and optics originally developed at the Philips Centre for Technical Training. T2Prof brings its courses on the market in exclusive cooperation with its partner High Tech Institute. High Tech Institute focuses on the marketing, sales and organization of these courses.

This article is written by René Raaijmakers, tech editor of Bits&Chips.