Richard Simpson - MTS Global Sales Manager
Richard Simpson, MTS Global Sales Manager

MTS Systems - electric actuation
Developed to meet NASCAR damper testing needs, portable electric "crank-type" systems subject dampers to sine wave motions at the race track.

MTS Systems - EMA Damper
Linear electric EMA systems subject dampers to a full spectrum of waveforms at the race track and in the laboratory.

MTS Systems - ePost
Linear Electric e-Post systems are ideal for full-vehicle buzz, squeak and rattle (BSR) and noise, vibration and harshness (NVH) testing.

Innovative Electric Actuation Strengthens MTS Test Solution Portfolio

To better meet the evolving needs of the global automotive industry, MTS recently acquired Roehrig Engineering, Inc. (REI) - renowned innovator of electrically- actuated damper test technology. Richard Simpson, whose career at REI started in assembly, proceeded to development engineering and culminated in vice president of sales, discusses the origins and evolution of REI electric actuation, and its future as an integral component of the MTS technology portfolio.

Q.  What prompted the development of electric damper testing technology?

The REI story begins with meeting the needs of NASCAR teams to perform precise damper testing at the race track. There are many factors that contribute to a vehicle’s performance on race day. Teams approach a race with an understanding of how a vehicle will perform on a given track based on the previous year’s event, but ambient temperature, humidity, weather, track conditions and the vehicle’s chassis will be different from year to year. All of these factors will affect the vehicle’s ideal damping rate. What teams needed was a product that would enable them to test and tune vehicle dampers for optimal performance on a given track, under the specific conditions occurring that day.

Q.  What was the REI solution to NASCAR’s need for track-side damper testing and tuning?

To meet this need, REI developed a line of portable electric “crank-type” dynamometers, which employ a scotch-yoke and belt-drive system to subject dampers to sine wave motions. These dynamometers were easy to use and capable of delivering the fast, accurate test results that teams needed to re-valve and tune shock absorbers based on input gathered from the driver during practice sessions. Economically priced and simple to maintain, they quickly became popular among NASCAR racing teams.

Q.  How did this early success with NASCAR teams spur further development of electric damper test technology?

The rapid adoption of the first-generation electric actuation products led to broader opportunities in other motorsports applications, from dirt-track racing to Formula 1, and eventually engagement with Tier 1 OEMs and their networks of damper manufacturers/suppliers. While these new users appreciated the portability and price of the crank-style products, their testing requirements were considerably more complex than the track-side needs of race teams. In response, REI brought a new kind of damper testing technology to market, the linear Electro-Magnetic Actuator, or EMA. In addition to the sinusoidal waveforms, EMA systems are capable of generating a full spectrum of waveforms, including triangle, square, sine-on-sine, variable sine, random and frequency sweep. In addition, these electric systems are far more portable than conventional damper test systems because they require no hydraulic power and distribution infrastructure.

Q.  What differentiates EMA technology from other types of electric actuation?

What makes these linear electric actuators distinctive is their combination of fixed, high-force neodymium magnets and moving ironless core electric motors. The lack of ferrous metal makes the motor extremely lightweight, which is what enables the actuator’s high frequency response and high acceleration. The ironless motor also means there is no attractive force between the motor and the magnet and therefore no risk of cogging effects that can compromise the velocity waveform. In addition to performance, this lightweight design and minimal infrastructure requirements enhance the portability EMA systems, making them ideal for deployment in laboratory, factory or race track environments.

EMA technology has also been refined for four-post, full vehicle road simulation. For such applications, a patented hybrid EMA design employs linear electric actuators to deliver dynamic force and motion, and pneumatic cylinders to support high static loads. The performance and efficiency advantages of this design are numerous. The linear electric actuators deliver the performance and quiet operation needed for meaningful buzz, squeak and rattle (BSR) and noise, vibration and harshness (NVH) testing, while the pneumatic cylinders effectively reduce current demand and operating temperatures, eliminating the need for complex water cooling systems or chillers - air cooling will suffice.

Q.  Who benefits from the performance and efficiency of EMA technology?

Many segments of racing industry have standardized on EMA equipment; virtually every NASCAR trailer that comes to a track has a portable EMA 2K system on board. It is a critical tool for race engineers, enabling them to measure and evaluate changes in a damper’s force/velocity curve and perform any needed fine-tuning in a very small window of time.

Vehicle and damper manufacturers, too, are realizing the advantages of EMA test systems. EMA systems deliver exceptional operational efficiency because they only draw power when the test is running. These systems are also very quiet, which is important for BSR and NVH tests. The lack of hoses and accumulators means they can be installed in smaller spaces and moved around the test lab more easily, and maintenance costs are low. In other words, the benefits of linear electric actuation align well with current industry trends toward energy efficiency, environmentally friendly operation and lower total cost of ownership.

Q.  How does EMA technology fit into the broader MTS test solution offering?

EMA technology strengthens the MTS portfolio, enabling the company to better pursue solutions to the evolving spectrum of testing challenges facing the global damper and automotive industries. With the addition linear electric actuation technology, MTS now offers the industry’s broadest selection of damper test solutions for garage, track, proving ground and laboratory, and is well-positioned to address growing industry demands for greener and more efficient test solutions.

Contact MTS today, and learn how MTS linear electric actuation technology can help your organization perform damper and vehicle performance testing with greater efficiency, ease and confidence.




MTS Systems

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Eden Prairie, MN USA

Tel: 952.937.4000
Tel: 800.328.2255
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