Design And Study Of Tractor Electric Hydraulic Power-Assisted Steering System

Aiming at the disadvantages of traditional hydraulic power-assisted steering system,a improved design for electric hydraulic power-assisted steering system is made,changing from single piston rod actuation into double piston rods,and carrying out electronic control to steering system.The steering mechanism is analyzed and parametric designed.Under the condition of Pro/E,3D modeling is made for steering mechanism,moreover,hydraulic system and its main parts are designed and selected correspondingly.In terms of controlling,through the analysis of the three typical steering characteristic curves,and with tractor working environment,this paper is to select linear type steering characteristic curve as control strategy.PID algorithm is decided as control algorithm for this system,and TQ—660 series torque sensor is selected for this system.The hardware electric circuit of control system is designed.At last,assembly experiment table of CAT hydraulic system is used to do imitation test for steering system.The analysis of test result proves the liability of electric hydraulic power-assisted steering system in tractor operation.Imitation test shows that compared with traditional hydraulic power-assisted steering system,the obvious characteristic of electric hydraulic power-assisted steering system is following assist,which means that it can provide strong power-assist steering in farming area and weak power-assist steering on highway.It improves tractor's controllability on the basis of energy conservation and emission reduction with good power assist and achieves design purpose and requirements.