European law stipulates that from 2025 onwards, newly registered fleet vehicles including trucks, passenger cars and sports utility vehicles (SUVs) must have 37.5% lower CO2 emissions, compared to the emission limits valid in 2021.
Car manufacturers are therefore working to electrify their vehicles, increase active control of driving dynamics, and improve driving resistance measurements to achieve the necessary reductions. However, switching to electric powertrains leads to higher axle loads than their combustion counterparts, and thus the optimisation of driving dynamics and driving-resistance measurement requires even more precise measurement technologies.
In response, the Kistler Group is launching the RoaDyn P109 wheel torque transducer (WTT) for vehicles weighing up to 3.5 tons. The WTT has a measuring range of up to 9,000Nm (high range) or 900Nm (low range) and the company says it delivers precise measurement results, even with high axle loads.
The P109 replaces the rim star of the wheel and transmits the traction torques to the onboard electronics in the vehicle, all captured precisely with piezoelectric quartz sensors.
The wireless signal transmission is carried out by the telemetry module. The signals are electronically amplified directly in the wheel and can be transmitted digitally to the developer’s data acquisition system.
Kistler says that the process of mounting the wheel torque transducer is comparable to changing a standard wheel, and can be completed in less than 15 minutes. The P109 is available for wheel rim sizes from 13 to 20 inches, with other sizes available on request. Additional adapters are available if different vehicles need to be aligned.
The P109 transducer comes with a low moment of inertia and offers four temperature channels to integrate additional K-type temperature sensors. The operating temperature ranges from -25 to +80°C.
In addition to vehicle dynamic measurements in vehicle development, the RoaDyn P109 wheel-torque transducer is also suitable for powertrain analysis as well as evaluation and validation of control and ADAS systems. Gear development, brake tests and mandatory safety tests are further areas of application.
