Comparative Study On The SWIFT Model And The FTire Model

Vehicle dynamics simulation technology has been widely used to study riding comfort, handling stability and durability. More and more people think that The biggest impact of the model cars is tire model. Intermediate and high Frequency Tire Mode become a focus in the research of vehicle ride comfort. Intermediate and high Frequency Tire Mode directly influences the precision of vehicle dynamics in the study of riding comfort. At present, there are SWIFT, FTire, RMOD-K, CDTire, Gim 2-dof tire model, etc. SWIFT and FTire tire model are widely used. This two kinds of tire models each have advantages and disadvantages, CAE engineer don’t know how to choose which kind of tire model. So that this paper studies the mechanism of two kinds of tire model, compared to two kinds of tire identification precision, speed of simulation, test needs, identify cost and, etc. the main research work carried out as follows:1, The modeling mechanism of SWIFT tyre model is studied, and it is made by magic formula, grounding block sliding model, serial elliptic equivalent road model and rigid ring model. First of all, the magic formula is introduced, including basic parameters, the specific formula, the modeling points and features. Secondly, ground mass sliding model is introduced by linear transient model, to establish grounding quality block sliding model based on Simulink, and verify its accuracy. Again, this paper introduces the equivalent pavement model, including tyres inclusive characteristics, equivalent pavement experience model and serial elliptic model. Finally, this paper introduces the three directions of rigid ring plane model modeling mechanism, built the modle of tire high-speed drum pasing convex block based on Simulink.2, FTire tire model modeling mechanism is introduced, including the structure model, tread model and thermal model and wear model. First, this paper introduces the freedom of beam unit, the connection between rim and beam, the connection between adjacent beam unit. Secondly, this paper introduces the number of the tread blocks, distribution characteristics, connection between tread blocks and beam unit, the calculation of between tire and road surfaces. Again, this paper introduces the thermal model, including the factors to generate heat in the process of rolling tires, thermal modeling mechanism and structure of FTire. Finally, this paper introduces the wear model of tread instantaneous wear rate and tread blocks of energy loss, tread temperature and force calculation formula of tread blocks. The instantaneous wear rate describe the depth of tread pattern over time, the wear rate indirectly affect tyre mechanical characteristics.3, introduces tire mechanics characteristic test and test bench, the need of test data establish SWIFT and FTire tire model and the parameter identification method. First of all, this paper introduces various kinds of tire mechanics characteristic test, including the steady state characteristic test, static characteristic test, transient characteristic test, dynamic characteristic test. Secondly, this paper introduces the test condition test method, test outline and parameter identification methods of SWIFT tyre model, including basic parameters, tire steady state characteristic test, basic characteristic test tire, tire enveloping characteristics test and tire dynamic characteristics test. Again, this paper introduces the test data need to build FTire tire model, test outline, basic parameters, including Basic parameters of the tire, tire static grounding mark shape characteristic test, tire steady state characteristic test, tire dynamic characteristic test. Finally, this paper introduces the using of COSIN FTire/fit for FTire parameter identification and the Identification process.4, Compare respectively from the identification precision, the simulation speed, complexity of obstacle negotiation simulation, identify cost of SWIFT and FTire tire models. But because my ability is limited, the comparing result is not absolute, for reference only, welcome to correct me if you have any questions. In short, SWIFT tyre model is suitable for vehicle handling stability and ride comfort simulation. FTire tire model is more suitable for vehicle ride comfort simulation.