Research On The Effects Of Assist Characteristic Of EPS On Vehicle Handling And Stability Based On Virtual Prototyping Technology

The steering system is used to control the direction of the vehicle running, and it is also the main factor for the handling and stability of vehicles. Its performance will affect the safety and comfort of vehicles. So the research of the steering system is the important one of the handling and stability researches. Because the developing of the steering system, the Electric Power-Assisted Steering (EPS) is good for environment protection, economical fuel, safety and comfort. More and more EPS are used to install in the vehicles. The development of the computer technology and the application of the software ADAMS help us do more researches about the EPS better.The thesis is based on the most important project of Zhejiang province in 2004. Base on the analysis of EPS, using the ADAMS software, according to the national evaluation standard on the vehicle handling and stability, this thesis research the effect to the handling and stability when the EPS use three kinds of assisted characteristic lines, the straight line, the broken line and the curve line. The thesis also researches how to choose the assisted characteristic lines.The Principal contents studied in this thesis are as follows:1. Reading lots of literatures and data, researching the main types, the develop process and the current situation of EPS and its assist characteristic. Decide the research direction to solve some problems of EPS.2. Studied on the national evaluation standard of vehicle handling and stability and the foreign evaluation standard of the steering wheel force.3. Based on the multi-body dynamics, using the ADAMS software, built the vehicle model including the front and rear suspension system, the steering system, tires system and power train and brake system. Applied a new way to add the assist power on the steering system and compiled the files which are used in the simulation. According to the national standard, the virtual experiments (the steering efforts test and double land change test) were carried out. Compared with the real experiment results, the model is proved to be reasonable and applicable.4. According to the virtual experiments compiled the driver control files and driver control data files. Raised the assist-characteristic equation. of the curve line Used the Uniform Design method and the national evaluation method of vehicle handling and stability, simulated and analyzed the return ability and steering effort when the EPS use three different assist characteristics. Using...