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Because of its mobility, great flexibility, convenient to move, working efficiency, wheeled machinery are widely used for material digging, moved, hoisting etc. In recent years, more and more technicist begins to pay close attention to the study of wheeled machinery.Steering system’s main functions is to manipulate and change vehicle traveling direction, not only keep vehicle driving along a line, and guarantee the stability of the vehicle steering flexibility. Full hydraulic steering system is one current steering system widely used in hydraulic system design, especially developed recently in load sensing full hydraulic steering system. Because of its energy-saving effect, it becomes a hotspot. This type of system is equipped with priority valve, on the one hand, it is can according to the requirements of steering oil-way priority to assign flow, on the other hand, this system makes it necessary to maintain the normal work, the rest part can flow almost supply to work oil-way, so it improves the efficiency of the system.Based on the introduction of load sensor type hydraulic steering system structure and working principle, the components of the system such as hydraulic pump, priority valve, steering cylinders and related steering mechanism are respectively analyzed and correspondingly established its kinematics and dynamics equation. Ignoring some minor factors, the simple mathematic model of the system is built. On this basis, system model is analyzed by the transfer function method, and the factors to influence the static and dynamic characteristics of the system are theoretically analyzed. Meanwhile, the digital simulation model is built by MATLAB/SIMULINK tool box. Static and dynamic characteristics are simulated and obtain the structural parameters’ influence law. Finally steering mechanism is optimized and analyzed by using MATLAB optimization function (fmincon function). and by using the virtual prototype simulation software ADAMS (View module and Hydraulics module), Mechanical-hydraulic union simulation model of system is established, the analyzed experiment show that the built model of rationality.
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