Analysis And Research On The Characteristic Of Electro-Hydraulic Speed Servo System Affected By Load With Large Inertia And Elasticity

As one of the most vitality offset of hydro-liquid drive and control field , Electro-hydraulic proportion controls technique fills up a blank between traditional on-off hydraulic pressure control technique and servo-control technique. Because of the superiority of cheapness, stabiles, anti-pollution, low energy-cost, it is probability that Electro-Hydraulic proportion controls technique will replace servo valves in application of the general industry. To apply the electro-hydraulic proportional valve to close-loop controlled system and improve the capability with advanced control strategy is significant for regeneration traditional industry controlled with on-off valve or open-loop proportional valve, it will develop and perfect this technique.In the billet grind machine, the flan which be grinded is drawn by the car driven by hydraulic motor. Steel wire rope draws the car moving on the rail, the load has large inertia and elasticity because of the existence of steel wire rope in the chain of transmission. In the realistic use, the pressure impact will beengendered at the time of changing the direction of the car, the higher impact will bring on the break of the steel wire rope. The paper emphasize on the modeling of the system with elasticity load and analyze the effect of the main elements on the steel wire rope by means of simulation.Based on the analysis of the characteristic of the load, the model of the motor speed system controlled by proportional valve with large inertia and elasticity is established. The effect of the load with elasticity on the motor speed system controlled by proportional valve is compared with which has pure inertial load and the ways are put forward to improve the characteristic of the system. At last, PID controller is used to rectify the speed controlling system of the car. As a result, the characteristic of the system is improved.