“We need smart hydraulic systems.”

Marginal Column
Prof. Dr. Ludger Frerichs

Prof. Dr. Ludger Frerichs
has been Director of the Institute for Mobile Machinery and Commercial Vehicles at the Braunschweig University of Technology since January 2012. Professor Frerichs studied mechanical engineering in Osnabrück and Braunschweig and earned his Ph.D. in Stuttgart-Hohenheim. From 1990 onwards, he held managerial positions with renowned manufacturers and worked on the development of agricultural machinery and industrial trucks. For years, he has been involved with the VDI and VDMA, promoting research and cooperation between universities and the industry. He is the editor of the Agricultural Technology Yearbook.

Copyright Photo: Prof. Dr. Ludger Frerichs


November 2016


Mobile working machines have been accompanying Professor Ludger Frerichs for his entire professional life. The Institute Head of the Braunschweig University of Technology is expecting the next productivity surge to come from the intelligent networking of the overall process.

Aren't you tired of all the discussions about improving efficiency in mobile working machines, Mr Frerichs?

Not at all. That is and will continue to be an exciting task in all fields of research. Above all, when you ask the crucial question of what to do with the efficiency gained from the technical system. In the past, we placed great emphasis on increasing performance in terms of raising productivity for the customer. Now, as a sign of the times, I think the second aspect is becoming increasingly important, namely minimizing the outlay for the same performance. In other words, the conservation of resources not to mention the reduction of greenhouse gas emissions.

Why are you advocating the turnaround?

Because as a society we are starting to realize that climate change is actually taking place, and the pressure to take effective measures is clearly noticeable. For our product, mobile working machines, that means doing both: Depending on the situation, this means providing an adequate level of performance, for example, to increase productivity in agriculture, and reduce the quantity of resources with regard to the result of the work done. As a result, there is often a conflict of objectives, which can be solved only by looking at the entire production system. We need to think much more in terms of the customer's application. Among other things, the operator needs intelligent support in order to optimize the use of their machine and all its possibilities.

What role will hydraulics play here in future?

Hydraulics will prove its value in mobile working machines. But we will need to further develop them in the application system. The hydraulic power units and hydraulic valves need more intelligence and more precision. Intelligence in order to communicate the relevant information to all stakeholders in the system every second and hence optimize the system at lightning speed at the same time. We need precision in the components to minimize losses and ensure that the operator receives a "real-time" feeling for the undertaken operations. As a result, what we also get are intelligent hydraulic systems that generate highly relevant information for the application's entire system. Furthermore, hydraulic suppliers and OEMs need to think intensively about hybrid and inter-disciplinary solutions that will combine the best of all worlds.

That sounds like a coexistence of systems?

Indeed it does. Hydraulics, electrics and mechanics - any technology can find its place in the overall system and can demonstrate its specific potential in hybrid solutions.

How can you find the right balance between the systems?

Researchers and developers need to stop focusing just on the single components and, based on the application, start looking at the overall system. That will compel people to become extremely open and promote close cooperation between all involved. This calls for an equally non-ideological and realistic consideration of technologies. It is not about sticking to the status quo or jumping on the next hype. What we need much more is a culture of information and communication.

In this context, the electric drives of mobile working machines is an issue. Why has the discussion quieted down?

Because after the initial hype, reality has now returned and the painstaking everyday work of the engineers is in progress. They need to find answers to the question concerning electric drives and which applications they maybe more suitable for. This question is relevant to both the individual function as well as the entire machine in the application. I'm very confident. Because in all areas, whether electric machine and power electronics or storage and charging technology, intensive development work is being carried out at considerable expense. At present, this is mainly being driven by the car industry. According to our experience, this means there are only a few components we can actually use for mobile working machines, yet the technologies are being significantly advanced. Against this backdrop, interesting products could emerge for us. With regard to electrical drives in the machine concept, we can clearly see what is going to happen with industrial trucks. In the case of counterbalanced lift trucks, the market is shifting from combustion engine-powered lift trucks to battery-powered electric lift trucks. The change is particularly significant in areas where forklifts are partially used "indoors". The same is happening with agricultural and construction machinery. I assume that any machine that needs to operate in closed rooms will sooner or later be electrically powered.

When it comes to "intelligence in the system" are we actually talking about agricultural and construction machinery 4.0?

Basically yes, but not only. By the way, I prefer the term "cyber physical systems" because it emphasizes the necessary holistic view of the system. Thanks to the availability of modern communications technology, we are able to exchange real-time data. However, intelligence does not come through networking, but only by taking one step further and intelligently using the information in the system. The automation that I see happening in parallel is also spawning intelligent solutions and possibilities for use, depending on the stage of development. We should also not underestimate the mechanical or hydraulic developments. They are often no less "smart", as the English like to say with a tad more understatement.

Doesn't "smart" mean that the operator will become increasingly incapacitated?

No, that would be catastrophic. But it also depends on how far we push automation forward in the respective machine application. Basically, the person that's in charge on site needs to retain decision-making powers, and we should not patronize him. On the basis of the topic I just mentioned, it will quickly become clear as to what should happen with the resulting efficiency gains. If a severe thunderstorm approaches, the driver of the machine or the squad leader can turn off the eco mode and drive the harvest back at full speed before the first drops fall. And then there's the truck driver who doesn't want to unload the two last trucks on Friday afternoon just before the weekend in cruising gear, but instead wants to utilize the maximum performance of his machine. This is where the "smart" user friendliness supports the performance of the machine.

Mobile working machines are now going global. What does that mean?

This means a high degree of design discipline in a sophisticated engineering concept and a clear "no" to over-engineering. In the regions, we need solutions that meet expectations and demands. Maybe even a little "more than expected" to help the market, but not more. Modularity is a key factor in the design-to-region concept. It helps to keep costs in check.

With regards to "global": Agricultural machinery manufacturers are globally seen as trendsetters. Why is this the case?

There are at least three reasons for this. A look at the balance sheet shows that agricultural machinery manufacturers invest more in research and development than other industries do. They lie, for example, well above intralogistics or construction machinery. On the other hand, agricultural machinery manufacturers often have customers who both operators and users. The farmer or hired hand also sits on the machine, and has a rational approach and emotional attachment to it.

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