| Electro-hydraulic proportional control technology, as one basic technology ofengineering equipment’s automation control, is widely used for its simple controlprinciple, high control precision, strong ability to resist pollution and moderate price，ithas become an indispensable means in industrial machinery, construction machineryand defense highly sophisticated products. In this paper, research object is bogieseparation device, its hydraulic system is analyzed and its hydraulic system schematicdiagram is designed. What’s more, electro-hydraulic proportional control technology isapplied to lifting loop, rotating loop and variable pump which are taken comprehensiveanalysis and research.According to the features and requirements of different moving parts, analysismovement process of each moving parts and complete hydraulic principle diagramdesign of lifting loop, rotating loop and position loop. Analysis forces of hydraulicsystem，calculate the main parameters of each loop and then obtain the requiredpressure and flow of each loop.Compare synchronization precision of "equivalent mode" and "master-slave mode",choose the right synchronization control strategy of lift loop. Build mathematical modelof electro-hydraulic proportional synchronous control system, and so the damping ratioof proportional valve and open-loop transfer function can be obtained. PID correction istaken for the system whose parameters of PID controller are determined by critical ratiomethod. Simulation analysis of system is made by Simulink software, step responsecurve and sine response curve of synchronization system are obtained, which verifiesthat the system can meet synchronization requirement.This paper introduced the working principle of bogie rotating mechanism, themathematical model of rotating mechanism hydraulic system is established, frequencycharacteristic analysis is made by Simulink software and open-loop Bode diagram andNichols chart are drawn in order to get phase margin and amplitude margin of thecontrol system, which can verify that the system can meet the requirements of stabilityand rapidity. Simplified slewing mechanism dynamics model is established in theADAMS, the ADAMS software and MATLAB software communication is connected,and then the joint simulation analysis of the rotating mechanism can be realized.Hydraulic pump is the power source of the whole hydraulic system, it directly affects the performance of each loop. Detailed analysis of working principle and controlcharacteristics is made for constant pressure variable pump and proportional pressurecontrol pump, variable mode is selected according to the pressure and flow required byeach loop of the hydraulic system. In addition, this paper puts forward a proposal thatmaking simple transformation for constant pressure variable pump, and as a result, theconstant pressure variable pump becomes an electro-hydraulic proportional pressurecontrol pump, which can meet the requirement of pressure and flow of each loop. |
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