A Comparative Study On The Application Of UniTire And MF Tire Models Based On Adams

Tire dynamics is the cornerstone of vehicle dynamics research and vehicle control algorithm development.The mechanical properties of tires have a great impact on vehicle handling stability and driving safety.With the rapid development of social economy and technology,all major domestic vehicle companies have the strength to develop autonomous vehicles,but the research and application of tire mechanical properties are still insufficient.The accurate expression and application of tire mechanical properties by tire model is one of the key points to improve the efficiency of vehicle dynamics simulation and chassis development.At present,the most widely used steering stability tire model in the industry is the MF tire model proposed by Professor Pacejka of the Netherlands,namely the PAC model,and the Uni Tire model proposed by the domestic academician Guo Konghui.Both models have made outstanding contributions to the development of vehicle performance since their inception.In recent years,the Uni Tire model has been updated steadily with the support of the team led by Guo Konghui and Professor Lu Dang,while the MF model has basically stopped updating after 2012,and the model has become stable.In order to verify the expression effect of the new version of the Uni Tire model under various working conditions,this paper carried out a comparative study of the application of the characteristics of the two tire models,laying a foundation for further promoting the commercial application of the Uni Tire model.According to the above requirements,based on the research foundation of the tire model in the research group,the following parts of the work are carried out in this paper.1.Comparison of the modeling method and model characteristics of the new Uni Tire model with the MF modelIn the system of Uni Tire unified tire model established by Professor Guo Konghui,a new version of Uni Tire semi-empirical model is established.Theoretical analysis and comparison of the modeling ideas and characteristic parameters of the fully modeled Uni Tire model and the MF model,and the expression ability of the model under various tire experimental conditions,such as pure conditions,combined conditions,etc.,are carried out one by one.Comparison and analysis,and model simulation based on Adams Tire Testrig tool,provide guidance for the next development of Uni Tire model.2.Development of tire model STI interface based on Adams softwareBased on the new version of Uni Tire model established above and Adams software,the interface program which uses Uni Tire model and Adams software is developed.The overall workflow of the software model interface provided by the new version of Adams software and the functions of key subroutines are studied;the processing methods of the vehicle coordinate system and the land coordinate system in the interface program are also studied;the vertical force of the tire is analyzed in the software.Input and output problems and transient differential equation solving problems lay the foundation for the accurate establishment of the Uni Tire model interface.3.Analysis and comparison of vehicle-level operating condition simulation applicationCombined with the new version of Uni Tire model established above and its STI interface with Adams software,the working conditions are simulated based on Adams/Car,combined with the handling stability experimental data of the test rig and the corresponding established vehicle model,and then the typical handling stability conditions are established virtual experiments to verify the correctness of model linking.And in the vehicle dynamics simulation,a comprehensive comparison of the expressive capabilities of the Uni Tire model and the MF model,the use of the vehicle model to compare the simulation and experimental data under typical handling conditions,and the analysis of the responses of the two models to verify the practical application effect of the new version of Uni Tire model.In addition,for other special working conditions,such as dynamic characteristics under low speed conditions,vehicle crosswind stability,variable friction road surface,tire dynamic load,etc.,relevant simulation comparisons and verifications are also carried out.