Dynamic Wheel Load Measurements on Real Road Surfaces - What Accuracy to Expect?

In recent years we have seen drastic improvements of the accuracy of wheel force transducer (WFT) systems /1, 2 and 3/. These systems in most cases are calibrated just statically. What is the dynamic behaviour of the sensor? What can we expect towards the accuracy of the measured loads on real road surfaces as they are influenced by a number of parameters?

In the present paper quantitative results are reported out of a broad investigation of the effects of the following parameters

• road surface,
• rim stiffness,
• tire air pressure,
• velocity and
• wet road conditions.

The unique Wheel and Tire Testing Vehicle (“Universal Skid Resistance Measurement Device”) of Stuttgart University was used for the measurements on two highways. The WFT-signals are referenced to the multiaxial force sensing of this vehicle. These findings are compared to results derived from a rolling road flatbelt test stand reported in /6/.

With the reported results dynamic wheel load measurements can be more precisely evaluated from an engineering standpoint. Thus innovation and optimization in the fields of WFT application will be further fostered.