Control And Simulation Of Electric Power Steering System Based On ADAMS

Electric Power Steering system (EPS) is a new type of automobile steering system, which has a good controllability. It can make a better way to solve the contradictions of the’light’and’flexible’for automobile. It also has the advantages of reducing overall weight, improving driving security and producing less pollution. EPS is a high-tech of the development of automobile which has a wide range of applications.Virtual prototype Technology (VP) is a new way to develop products. It allows designer, user and producer can make design optimization, performance testing and manufacturing simulation to the origin products in a virtual environment at the early stage of product development. ADAMS (Automatic Dynamic Analysis of Mechanical Systems) is a well-known analysis software of virtual prototype which is made by American Mechanical Dynamic Inc (A part of MSC Software Corporation now). This paper simulates and analyzes a multi-body dynamic model of automobiles equipped with EPS based on ADAMS.Firstly, the structures, working principle and characteristics as well as of the current development of EPS are interpreted. Then it introduces the development of virtual prototyping technology and basic theory. At the same time, it focus on the ADAMS software in detail.Secondly, a multi-body dynamic model of automobile equipped with EPS is established, which includes the front/rear suspension、steering system、front/rear wheel、power system and brake system. Describe the simplification and assumptions of the model detailed as well as the way of how to realize the assist force.Thirdly, the dynamics model and the control strategy of EPS system are studied as well as a type of linear assist curve is posed. A control strategy including PID control, damping compensation control and returnability compensation is adopted. The closed-loop PID control system is established in MATLAB/Simulink. At last, the co-simulation method of ADAMS/Controls is introduced. Co-simulation technology is used in this paper to link the control model established in MATLAB to the mechanical model established in ADAMS. Assist force is the input of mechanical model, and it is also used as the output of control model. The outputs of mechanical model, wheel input torque and signal of vehicle speed, are used as the inputs of control model. The feasibility of co-simulation is verified through several manipulate stability tests.