Primary Research On The Objective Assessment System For The Tire Handling And Stability Performance

Tire is one of the most important connection between the vehicle and the road. All the vehicle forces from the road are transferred by the tires. That's the reason why tire plays an important role in vehicle dynamics. In order to satisfy the performance requirements from the vehicle manufactory, the tire company has to do a lot of tests to evaluate the tires. But tire tests are time-consuming, expansive and complicated. The life and performance of the tire production should achieve or exceed the requirements. That's the best result the tire company wish to see, in order to avoid the contradiction between the tire constructive design and the processed materials. Moreover, in order to cut the tire and vehicle development circle, the matching relationship between the tire and the vehicle must be understood, and the work should be finished before the tire and vehicle production. When challenge and competition are encountered doing these exploit works, a scientific work assessment is needed according to the actual instance so as to avoid some mistakes. The ability is confronted with all the challenges from the tire and vehicle mathematic simulation and the design works for the tire test equipments. Furthermore, for the sake of these equipments, economic assistance is inevitable.At present, there are two kinds of recognized tire assessment methods: indoor assessment and outdoor tests. Indoor assessment is a kind of method which can isolated predict the tire performance and be used in production guidance. FMVSS has raised a series of tire test criteria for the local saloon cars, including actual dimensional measurements, tire disengage resistance test, tire stress test et. These tests are all typical indoor test items. Tires should be installed on the vehicle when doing outdoor tests. It gives emphasis on consideration of the matching relationship between the tire and the vehicle, including tire wearing, traction performance, tire noise, ride performance, handling performance et. And handling performance is always the matter mostly concerned by the vehicle manufactories, so the assessment of the tire handling performance is undoubtedly the focus that the tire company pays attention to.Apparently, tire performance assessment cannot be limited in the isolated assessment for the dimension, wearing capability and life. A whole performance assessment based on matching should be used. This paper made reference to the vehicle handling performance assessment based on the total variance analysis and brought tire handling performance assessment from the matching point of view. So, it includes some works shown as below:First,A subjective assessment method of tire handling performance was brought forward. We finished the subjective assessment tests using appointed testing vehicle with four different type of testing tires. Two drivers participated in the tests. They should give the subjective scores for every performance tests according to the subjective assessment method mentioned above. At the same time, the objective vehicle response parameters were recorded using VBOX.Second,Making reference to Pro.K.H.Guo's assessment ideas based on total variance analysis, some primary objective indexes of tire handling performance assessment were proposed according to the contradistinctive analysis between the subjective assessment results and the objective test record, so as to constitute the objective tire handling performance assessment system. It could be treated as two layers. The first layer was the total performance that had three aspects including linearity, high-speed handling and high-speed steering to assessment tests. The second one was the assessment tests to objective indexes.Third,The virtual models of testing vehicle, tires and ground were constituted in CarSim, so we can do those simulated tests according to the national standards. After comparison between the simulation results and the real test data, we finished the model validation work. Then we did virtual assessment tests based on the correct model validation, analyzed the test results and further proposed some reasonable assessment indexes. Finally, the primary objective assessment system for the tire handling performance was ameliorated.Finally,It is those subjective assessment results and the objective assessment indexes which optimized the weight number in the objective assessment system. Using the weight number, we recalculated the indexes according to the objective tire handling performance assessment system. Contrast to the subjective assessment sort order, it is coincident between the subjective assessment results and the objective assessment results which were calculated from the optimized weight number.