Testing total vehicle durability!

Ford Europe commits many man hours to acquiring data from prototype test vehicles at its test track at Lommel in Belgium and, during the past 13 years, much of the Road Load Data (RLD) has been derived using Kistler RoaDyn Wheel Force Sensors over a wide variety of road surfaces. Ford has now upgraded its test capability with the purchase of ten of the latest Kistler RoaDyn measuring wheels and a set for use on test lab based vehicle simulators to ensure correlation between road and lab, a total investment of approximately €1M. The modular design of the Kistler RoaDyn Wheel Force Sensors enables Ford to test an extensive range of vehicles with wheel sizes from 15” to 19”.

According to Ford Europe’s RLD Supervisor, Mark Linn, the RoaDyn system is used on prototype vehicles being subject to total vehicle durability testing on a wide variety of road surfaces, from handling tracks to cobblestones and large potholes.

The data from the Wheel Force Sensors are used to predict the durability performance of vehicle chassis and body using CAE tools and also in the laboratory to provide load data to be applied to single suspension components and complete subassemblies, the objective being to combine minimum component weight with maximum durability to reduce total unsprung weight for best suspension performance.

Each RoaDyn wheel uses a number of three component strain gauge sensors to provide data that are used to precisely calculate the forces and moments acting on the rotating wheel. The high measuring accuracy of the precision load cells is retained during transmission as digitization takes place on the wheel to eliminate transmission interference from brake heat, movement, vibration, etc. The measurement of individual values with separate load cells also leads to an improvement in the interchannel crosstalk. As the original load cell signals are known, rapid error diagnostics is made possible. To maintain long life of the system, individual load cells can be replaced without impairing the overall quality of the sensor.

The RoaDyn Wheel Force Sensors can be constructed using either aluminium or carbon fibre reinforced (CFR) wheel rims, depending on the wheel size and vehicle loads.
During test, the measuring wheel replaces the standard wheel and must be as strong without affecting the kinematics or the handling of the vehicle. The Kistler Wheel Force Sensors using CFR are much closer to the weight of the standard wheel than measuring wheels made from aluminium or steel and have minimal effect on the kinematics or the handling of the test vehicle.

Over the past 13 years, Kistler Instruments has expanded its range of vehicle test solutions to include Corrivit™ optical speed and slip sensors, wheel vector systems and laser ride height sensors, offering the automobile industry a complete vehicle dynamics and durability solution.