The Research On The Matching And Control Technology Of EPS Applied On Mini-car

Electric power assisted steering which is the future of steering technology has advantages of smaller volume, lighter weight, simpler structure, easier installation and maintenance, lower consumption, better environmental protection,etc.Moreover, it provides different steering feel by adjusting assisted force according to vehicle speed.A lot of external famous viehcles have adopted this kind of steering system.Its technology is more mature than our nation, especially key parts/assembliy development.Therefore, it is necessary for minivan automobile industry of our country to master this kind of steering system as soon as possible. It is of great importance to research it.The thesis aims to research the modeling, dynamic analysis,control of EPS and the rules of vehicle handling dynamics,to make a theoretical basis for the design and development of EPS,to provide references for EPS design, development and matching with minivan.This thesis makes some advance on these following aspects:Steering wheel torque driver desired at different speed is obtained by analyzing the cause of "steering feel",composition of steering force and source, interacting factors and relationships of Electric power steering system.Then requirements for assisted torque of EPS are made. The Multi-body Dynamics Analysis model for Complete Vehicle is built for the minivan as an example. The veracity of this model is validated by real car test data, and foundation for the next analyzation is also laid.Take national standards and research as references, test and assessment methods about low-speed steering portability, high-speed handling and stability, vehicle dynamics detection are presented to provide performance test work with regulations.The basic requirements about EPS assisting performance are possessed to steering force performance under different operation conditions, so does three normal assist types and curves.Performance curve with beeline is achieved, and the ideal steering torque data and curve for dynamic simulation research are chosen.Performance curve with beeline is controlled by Dynamics Control System consisted of EPS modele and Multi-body Dynamics Analysis model for Complete Vehicle.Finaly the correctness of assist performance design is validated by vehicle steering assessment regulations discussed in the third chapter. The design could meet the driver subjective assessment reqirements about complete vehicle performance. By way of studing the types and control technology of EPS in this thesis,seeking the matching methods for EPS and minvan.By means of combineing simulation and test,the key matching technology between EPS and minvan for hadling performance is studied.And electron control simulation platform of chasis is built, providing theory and practice foundation for EPS design and development of minivan enterprise.