Search Results

Based on the results of “An Evaluation of the Mechanical Properties of Wheel Force Sensors and their Impact on to the Data Collected During Different Driving Manoeuvres” Herrmann et al. (SAE Paper 05M-254) a second, detailed investigation has been started to acquire additional information. In this previous investigation, it has been found out, that a difference in mass can be clearly identified in the signals. The current paper summarizes the results of a detailed investigation, which has been performed at DaimlerChrysler Stress Lab in Auburn Hills, with a fully equipped vehicle - a set of 2/4 Wheel Force Sensors plus several acceleration sensors as well. Through careful research and testing it is expected that the differences in the dynamic behavior can be specified with better accuracy than in the previous study.

To evaluate traction and velocity performance and other operational properties of a vehicle requires data on some tire parameters including the effective rolling radius in the driven mode (no torque on a wheel), the effective radii in the drive mode (torque applied to the wheel), and also the tire longitudinal elasticity. When one evaluates vehicle performance, these parameters are extremely important for linking kinematic parameters (linear velocity and tire slip coefficient) with dynamic parameters (torque and traction net force) of a tired wheel. This paper presents an experimental method to determine the above tire parameters in laboratory facilities. The facilities include Lawrence Technological University's 4x4 vehicle dynamometer with individual control of each of the four wheels, Kistler RoaDyn® wheel force sensors that can measure three forces and three moments on a wheel, and a modern data acquisition system. The experimental data are also presented in the paper.

In recent years wheel dynamometer measuring systems,using strain gauge and quartz technologies, have been optimised and are mature now. For specific fields of application the use of sensors based on either of the two measuring technologies would be the technically optimal choice. For technical, practical and economic reasons often two systems in parallel couldn't be used and thus limitations needed to be accepted. In order to overcome these limitations Kistler integrated sensors with both measurement technologies into one product family. Using results from practical applications and investigations the paper describes the new potential to get better test results faster. Kistler continously works towards a better integration of engineering processes (numerical simulation, testing on benches and in the vehicle).

Since decades KISTLER is contiuously innovating in the field of piezoelectric sensor technology. This paper describes major technological progresses in the field of rotating wheel dynamometers: the six-component Rotating Wheel Dynamometer RWD and the Rotating Wheel Torque Meter RWT. First the systems are explained in detail, then outstanding applications in vehicle development, tire power loss determination and tire deformation investigation are given. An outlook on upcoming innovations concludes the paper.

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/.