Modeling And Simulation Of Electro-Hydraulic Power Steering System

Along with the progress of the electronics industry, the automotive electronics industry have greatly increased in order to enhance the performance of the system, the systems have installed all kinds of electronic products. To make vehicle power steering lighter, more fuel-efficient and safer, the research for all electronic steering products to be studied.At present, the steering system technology has been mature and has more and more types of steering system: Mechanical steering systems, Hydraulic power steering system (HPS), Electro-hydraulic power steering system (EHPS), Electric power steering system (EPS), the Steer-By-Wire system.Because traditional hydraulic power steering system is still dominant, and there are some of its shortcomings, it's alteration and upgrade becomes more practical meaning. At present, considering the economic costs and operating results:Compared with the EPS system, EHPS makes the hydraulic system used to feel relatively smooth, feel good; the previous HPS system can be a relatively simple modification to be EHPS systems: EHPS systems also inherited the advantages of HPS systems to provide adequate assistance. therefore, Electro-hydraulic power steering system is the best choice, it can offer more secure handle and more saving energy effect. In the foreseeable future, electro-hydraulic power steering system will have been some living space.Automotive Electro-hydraulic power steering system is a new technology in on the basis of the traditional hydraulic steering system, EHPS systems can provide for people to feel more comfortable steering and more economical energy consumption, it′s research will be meaningful.This paper researches modeling and simulation of automotive electro-hydraulic power steering system as well as the relevant characteristics of power and control strategies ,it provides a theoretical basis for the electro-hydraulic power steering system design and development, the main contents of this paper are as follows:1. Introduces the structure of EHPS that it has composed of two parts of electrical installations and mechanical devices , principle of EHPS through speed and steering wheel angle velocity as input control signals to control the motor speed, the advantages and disadvantages compared to HPS , status quo and development trends of EHPS at home and abroad.2. The power of analysis of EHPS: Set principle of the power curve, give the driver's favorite steering Torque as an ideal steering Torque, and analyze the same points and different points of the HPS and EHPS power curve . design a reasonable EHPS power curve with the ideal power characteristics , computer power gain through the formula, Using Matlab Toolbox to curve fitting3. EHPS control strategy research: The analysis of EHPS on basis of performance, handling and stability, fuel. taking into account the steady steering and emergency steering , advance the control strategy plan based on speed, steering wheel angle velocity , the steering wheel torque. In order to achieve the above analysis, this paper brings forward rotate speed and current closed-loop control algorithm on basis of PID and the corresponding threshold logic diagram, Last concludes with a flow chart of the entire control strategy4. Based on the structural characteristics of EHPS , this paper proposed AMESIM and SIMULINK joint simulation of the entire EHPS systems and sets up vehicles and tires dynamics modeling, sets up the hydraulic model of AMESIM and the mechanical parts model, control parts model, the vehicles and tires of SIMULINK. EHPS systems simulation test includes simulation model of DC-PID control and simulation of power steering .it is feasible through the analysis of the simulation results to verify control strategy.5. Based on the above analysis of the full text, it designs the hardware of test-bed of EHPS, according to design requirements of bench test hardware system, it constructs and selects hardware of the bench test system. This paper confirms the scheme of the test bed of EHPS.In summary, this paper researches the assistance and the control strategy of EHPS, identifies the specific control strategy options and control algorithm, and establishes EHPS vehicle simulation model .this paper lays the foundation for the researches of EHPS, has a certain reference value about the development and design of EHPS...