7-Post test rig from thyssenkrupp Bilstein: Booster for suspension development
The driving dynamics of a vehicle are essentially defined by the properties of its suspension: in road vehicles, the suspension plays a key role in determining the driving experience – in motorsport, it is decisive for victory or defeat. The suspension tuning is therefore of utmost importance. The demands on suspension development are growing, particularly in times of increased cost pressure and ever shorter development cycles. With a new innovative vertical dynamics test rig, suspension specialist thyssenkrupp Bilstein is opening up new and urgently needed opportunities for suspension analysis and development for its partners – automotive manufacturers and racing teams.
With a new location directly at the Nürburgring circuit, the suspension experts from thyssenkrupp Bilstein have further expanded their service for customers from the automotive and motorsport sectors. With the brand-new, state-of-the-art test rig, automotive manufacturers and racing teams can analyze and tune their suspension systems even more effectively. The location of the BILSTEIN Competence Center in the immediate near of the legendary racing track in the Eifel region represents a logical choice – after all, it is not only numerous international racing teams that are based here. This is also where the beating heart of development work in the automotive industry can be found: all the well-known automotive manufacturers put their prototypes through their paces on the Nürburgring's Nordschleife track section.
Simulation of various road conditions, right up to complete racing tracks
The new 7-Post rig, a high-performance vertical dynamics test rig with seven hydraulic rams, can be used to simulate the driving behavior of a wide range of vehicles: from road vehicles to prototypes and racing cars. "Four hydraulic rams simulate excitations from the road surface in the vertical direction," explains test rig engineer Andreas Simon. Accelerometers and suspension travel transducers on each wheel and on the chassis measure the vehicle and wheel movements resulting from the excitations of the hydraulic rams. The spring/damper configuration can be optimized on this basis. "The three additional hydraulic rams simulate the vehicle's body behavior and make it possible to look even more closely at complex driving dynamics," says Andreas Simon.
A wide variety of route profiles and road conditions are simulated: from bad roads with undulations and manhole covers through to complete racing tracks. Another variant is particularly interesting for OEMs: "We can also run completely synthetic signals that would never appear on any road in such a form. They can be crucial in helping developers understand the vehicle and its response to certain frequencies," reveals Simon. Both manufacturers and racing teams can use the advanced test rig to gain a precise and complete understanding of the suspension system within the shortest possible time. Furthermore, together with BILSTEIN engineers, they can investigate and optimize the driving behavior in specific parameters, and develop the best possible settings. This is especially true for elite racing. Andreas Simon: "The higher up the racing series is in the hierarchy, the more complex things get."
Automotive manufacturers and racing teams are using the innovative test rig from thyssenkrupp Bilstein
Irrespective of whether OEM or racing team: the only thing that counts for them is the performance of the suspension. "With our new location at the Nürburgring paired with our state-of-the-art equipment and expertise when it comes to developing shock absorbers and suspension systems, we can now provide our customers with even more targeted support," says a delighted Martin Flick, Head of Motorsports at thyssenkrupp Bilstein. In these times of ever-shorter development cycles and increasing system complexity, they can save important development or tuning time by relying on our state-of-the-art test rig and the expertise of thyssenkrupp Bilstein's engineers.
Test times can be significantly reduced
For decades now in OE development, there has been no alternative to simulations owing to the increasingly complex suspension systems involved. Mechatronics function development with electronics and software is becoming increasingly important in addition to mechanical component development. The proportion of intelligent and networked suspension systems has been growing for years now. "Suspension development is becoming increasingly complex," confirms Martin Flick. "The amount of work an OEM has to do to get a prototype up and running is enormous. Against the backdrop of ever shorter development cycles in the automotive industry, we can offer our customers significant time savings with our 7-Post: we can support OEMs early on in the development stage with suspension tuning, for example by using a basic suspension to tune 80 to 95 percent of the vertical dynamics. Whereas OEMs used to have to drive their vehicles extensively on test tracks to work out the vertical dynamics, this can now actually be done on the test rig, even with vehicles that are not yet road-ready. In this way, we help to significantly reduce testing times."
7-Post test rig enables enormous cost savings
Racing calendars are full and tightly scheduled, and there are only limited testing opportunities available. Consequently, significant time savings also represent an important argument for racing teams to work with the 7-Post rig from thyssenkrupp Bilstein. Martin Flick mentions another decisive advantage of working with the vertical dynamics test rig: "In addition to the time factor, there is the attractive benefit of enormous cost savings." When parts of the development and tuning work are run on the test rig, this eliminates the need for expensive track rental, for example. As a rule, logistics costs can also be saved because the teams' racing cars and the OEM's prototypes are often located near the Nürburgring anyway.
Andreas Simon emphasizes, one of the key advantages is the reproducibility of the data. After all, when performing test drives on the test track, conditions can change with each run, Andreas Simon points out. "Test drivers might drive at a different speed at one point and with a different steering angle at another. On the test rig, meanwhile, the general conditions are always the same: the measurement results are therefore reproducible and thus offer fundamentally greater validity. Plus, the test teams aren't left at the whim of the weather or particular temperatures."
Andreas Simon does not believe that work on the test rig will one day replace real road tests, however. "A lot of tuning work, testing and analysis steps are now carried out on the simulator. This is mainly and additionally motivated by the need to cut down on the time and expense of testing at and on the track. But in the end, the test results have to be confirmed by real driving on the test track." At the same time, the subjective assessments of the test drivers remain an indispensable part of the test drive. "Because of this, even our advanced 7-Post will not completely replace testing on the track."
Expertise of test rig engineers is crucial
Nor will it entirely replace road testing at thyssenkrupp Bilstein, which also benefits from the in-house vertical dynamics test rig, as Martin Flick points out: "Colleagues from the performance and aftermarket department and OE driving test areas also make intensive use of the 7-Post and our testing expertise. Our performance and aftermarket colleagues specifically rely on it when developing high-performance products. The OE division is testing fresh ideas to gain new insights and further develop our technologies for series production.
For example, in terms of electric mobility: Because electrically driven vehicles are extremely quiet, disturbing noises are perceived much more strongly. Even the slightest suspension noise, which used to be masked by the noise of the internal combustion engine, is now suddenly a real issue. Martin Flick reveals: "We at thyssenkrupp Bilstein and our customers pay a lot of attention to the field of "noise vibration harshness", i.e. the study of audible or perceptible vibrations. Here too, the 7-Post helps us immensely."
The decisive factor in this is not only the advanced test rig technology and associated software, but particularly the expertise of the test rig engineers and all involved BILSTEIN Experts, as Martin Flick emphasizes: "What really counts is the person sitting in front of the test rig. Possessing the appropriate test expertise is the decisive factor. The 7-Post is an extremely powerful, complex tool that demands a lot of know-how and experience – especially in our field, where we are dealing with a wide range of applications and a very broad motorsports clientèle base ranging from amateur to professional teams."
State-of-the-art technology and blue-chip expertise in consulting
The heterogeneous customer structure provides a real boost in terms of systematically expanding the company's own expertise, as Martin Flick reveals. "We are able to massively expand our expertise precisely through the variety of different projects and areas of application, as well as intensive exchange with the OEMs' road test teams."
thyssenkrupp Bilstein offers its partners benefits through the combination of state-of-the-art technology, the highest level of consulting expertise and our central location at the Nürburgring. Nevertheless, the members of the test rig team have no intention of resting on their laurels. "The location is of course a great advantage for us," says Andreas Simon. "However, we also want to offer decisive advantages over our competitors from a technical perspective. In that respect, we're really working at full throttle just now."
And in this regard, things are indeed running very well for the suspension specialists in the BILSTEIN Competence Center at the Nürburgring: "Every week, we develop some new feature and ideas that we implement and put to the test." After all, they know all about speed at the Nürburgring.