Design, Simulation And Build Of A Electro-hydraulic Power Steering System Principle Prototype For Commercial Vehicles And Its Bench Experiments

Electro-hydraulic power steering system(EHPS) is a kind of electric controlpower steering system, which meets the requirements of the new energy system andthe intelligent vehicle. Hydraulic Power Steering(HPS) system represents the maturedevelopment of commercial vehicles’ steering system. However, HPS cannot meet theneeds of intelligent vehicles and new energy system. As new energy systems need toadopt the steering systems that are driven by electric motors. There’s urgent need todevelop electrical power steering(EPS) systems and electro-hydraulic powersteering(EHPS) system. The EPS system on commercial vehicles demand motors ofhigh quality, it needs the power consumption of3~5kW, which results in the largesize and heavy weight of the motors. EHPS is the important development direction, italso demands motors of high quality and it has complex mechanism.A new design of electro-hydraulic power steering system with accumulators andlinear solenoid valves is proposed to meet the much power steering energyconsumption needs of commercial vehicles and buses. By the application of theaccumulator, the power requirement of the driving motor could be significantlyreduced. And the system’s reliability is significantly improved. The research dealswith a commercial vehicle and its newly design EHPS system. The feasibility of thesystem is verified, and it lays good foundation of further products development.The thesis calculates the static performances of the pump，motor，and valve. Theprototype is researched so that the main parameters of the components can be settled.Then the models are selected.Models of EHPS mechanical subsystem, hydraulic subsystem, resistancesubsystem and controller subsystem were established and were analyzed based onMATLAB/Simulink.The liquid pipe and fixed parts are designed and built，the experiment bench isalso built. The controller is designed and built, the controller mainly consists ofpower module, driving module and signal conditioning module etc.The main components’ performance test and the experiment bench’s performance test have been done. The experimental results indicated that the systemis feasible and the simulation model is accurate.