RoaDyn® Piezoelectric Measuring Wheels for Extremely Small Torques

Kistler Instrumente AG: Aerodynamic and drive train optimization is necessary not least to meet the increasingly stringent CO2 emissions regulations faced by today’s vehicles. In addition to cutting fossil fuel consumption, drivers include the high crude oil price of around 100 dollars a barrel and the very tough new vehicles’ emissions legislation anticipated.

The torque measuring wheels of the RoaDyn P1xy series yield important information from simulation, test stand measurement and over-the-road testing.

Minute changes in torque are investigated in the road tests. Due to the very high dynamic range of the piezoelectric sensors, an appropriately chosen charge amplifier range allows extremely accurate operation of the RoaDyn P106 Type 9294B… up to three factors of ten below the mechanical limit of its measuring range. Its sensors with piezoelectric crystals have the following features: Freedom from aging and fatigue, excellent stability, with no sensitivity drift, high linearity combined with very wide dynamic range, high spring constant for high measuring element natural frequency, inherently low crosstalk and low hysteresis, compact construction.

Braking tests involving very high torques through to coast down tests with extremely small torques may be performed with this measuring wheel. Moreover, the rotation angle information of the PremiumLine slip ring transmission module can be used to largely eliminate rotation-dependent effects of the tire, drive train and other disturbance variables.

As a result the high responsivity, impressive accuracy and good reproducibility of the RoaDyn P1xy can be fully exploited even during over-the-road testing.

Kistler Group

Kistler’s core competence is the development, production and use of sensors for measuring pressure, force, torque and acceleration. Kistler’s know-how and electronic systems can be used to prepare measuring signals for use in analyzing physical processes, controlling and optimizing industrial processes, improving product quality in manufacturing and improving performance in sports and rehabilitation.

Kistler offers a comprehensive range of sensors and systems for engine development, automotive engineering, plastics and metal processing, installation technology and biomechanics.

A worldwide sales presence in the form of 23 group companies and 30 distributors ensures customer proximity, application support on an individual level and short lead times.

With a staff of 820, the Kistler Group is one of the world’s leading providers of dynamic measuring instrumentation. The Kistler Group achieved turnover of 195 million Swiss Francs in the 2007 financial year.