Swift inertial measuring
The company Resonic’s high-precision procedure determines the mass properties of engines, satellites and cars
Resonic, a young company from Adlershof, has developed a unique high-precision procedure to simply determine the mass properties of engines, satellites, cars and many other things. We visited their workshop.
A car that weighs 1,500 kilogramm sways softly back and forth. Force sensors record the movements of the snow-white Porsche Carrera with precision. They send important vibration signals to the laptop of one of the measuring engineers, which displays multi-coloured jagged graphs representing properties of the sports car including its mass and centre of gravity. “We measure five natural frequencies of the free vibration of the rigid body,” explains Oliver Kolakowski, who is responsible for measurement services at Resonic GmbH. Based on these measurements, algorithms calculate the centre of gravity and full inertial properties in just a few seconds. To be more precise: the researchers are particularly interested in the intertia tensor. This is the basis for, for example, car manufacturers to design low-vibration cars and to improve road behavior.
In the past, this could only be done using elaborate and error-prone procedures. What makes the patented Resonic solution so appealing, is that is anything but time-consuming or costly. Moreover: “Using our system, we can measure the dynamic behavior of virtually any freely moving object,” says Kolakowski. The company’s mobile solution has determined the inertial properties of objects as diverse as golf clubs, truck cabs and model ships.
Although this may be abstract in layperson’s terms, this offers great benefits: car manufacturers can optimise road behaviour and eliminate disturbing engine vibrations, which are transferred to the car’s interior as a humming noise. Moreover, the anti-skidding-mechanism ESP can be adjusted precisely to various vehicles types, making the elktest obsolete. The exact dynamic models produced by Resonic are increasingly sought after in astronautics: in order to steer a satellite in a precise and energy-saving way, one needs to know its centre of mass and inertial properties, otherwise it will spin or rotate. “These measurements are sometimes demanded at very short notice, but highly precise nevertheless,” says Kolakowski and tells us about a case when the Adlershof-based company had to measure the complete properties of a space probe module in a cleanroom only two days before that module went to space.
The ingeniously simple procedure was devised by Robert Klöpper, co-founder and managing director of Resonic GmbH. The mechanical engineer was a researcher and PhD student at the Tokyo Institute of Technology, where he was part of the research fields structural dynamics, system identification, and measuring technology. He studied at the University of Karlsruhe and the Grande École ENSAM in France, where he was the valedictorian of the class of 2006.
Nothing stood in the way of pursuing an academic career, but Klöpper wanted to put his own idea into action. And so, after many years in research, he founded his own company as a spin-off from the Tokyo Institute of Technology and the TU Berlin. It is his declared goal to become the market leader for mass properties measurements. He might succeed, seeing as car manufacturers, motorsports team and customers from aeronautics and astronautics are valuing the unique measurement systems. Many Japanese car manufacturers conduct challenging inertial measurements on a regular basis using the technology from Adlershof. Moreover, a famous South-German car manufacturer owns one of Resonic’s machines and it is in frequent use. Also, Volkswagen, who have bought two systems, gave praise to the swift measurement procedure, because “rare prototypes are quickly available for other tests” – saving them valuable time.
By Chris Löwer for Adlershof Journal