The project TIME (Tire Measurements) aims at the development of a common tyre measurement procedure for steady state cornering that will be reliable and consistent with realistic driving conditions.
State of progress:
The analysis of the differences confirmed the existing differences in tyre test results coming from different tyre test devices, whereas the second work package gave an extensive insight into the influences of different parameters on tyre testing results. Especially test surface curvature and test surface properties appear to have a large effect on the tyre F&M properties.
Vehicle steady state cornering testing showed that ISO testing often produces 'not-realistic' tyre testing conditions in terms of tyre temperature and tyre wear. A cruising type of test, with alternating left and right, creates more realistic conditions for a tyre and has therefore been used for defining the reference measurements.
The validation of the TIME tyre testing results of all benches showed, that some of the test benches - especially those who succeeded in implementing completely the TIME procedure - allow the prediction of the vehicle steady state cornering behaviour within a range of 10%, when a direct implementation of tyre TIME measurements into a vehicle&tyre model is applied, without any further adjustment. The approach used in the TIME project has resulted in a test procedure that aims at making people, involved in F&M tyre testing, more aware of the importance of both realistic tyre test conditions and vehicle test conditions.
Because steady state cornering is only one of the whole range of tyre properties relevant for Vehicle Dynamics applications, the TIME measurement procedure must be seen as the first step towards better correlations between vehicle and tyre testing on one hand and vehicle and tyre modelling on the other. It is expected that a common use of the TIME procedure will improve the efficiency of the co-operative (virtual) 'prototyping' work of tyre and vehicle manufacturers. The wide support within the project consortium by the automotive industry already indicates that the common test procedure for steady state tyre testing, can be seen as a basis for a next generation of tyre test procedures.
In order to develop vehicles, which have maximum active safety, car manufacturers need information about the so-called force and moment (F&M) properties of tyres. Vehicle manufacturers, tyre suppliers and automotive research organisations have advanced test equipment to measure the forces between a tyre and a road surface under a variety of loading conditions. However, because of the large differences in the test equipment and the measurement procedures used, the consistency of the tyre force and moment properties determined with the different test devices is a major problem.
First, the differences between results obtained with the main European tyre test devices have been investigated, followed by a parameter sensitivity study in order to explain the differences between the results obtained with the different devices. Force and moment properties of different types of tyres have been determined for three different passenger cars under realistic vehicle driving conditions in order to establish a set of reference measurements. These reference measurements have been used to establish a new tyre measurement procedure, which has been further developed and validated by making measurements with all the different tyre test devices used at the start of the project. Results obtained with the new test procedure have been used in vehicle dynamic simulation models in order to judge the procedure's validity and usefulness.
Funding SchemeCSC - Cost-sharing contracts
B24 9Q5 Birmingham
2628 CD Delft