Electro-hydraulic control system, method and device

Abstract

The invention provides an electro-hydraulic control system, method and device. The electro-hydraulic control system can comprise a hydraulic cylinder, an electro-hydraulic proportional valve and the control device, wherein the hydraulic cylinder controls moving of the load, the electro-hydraulic proportional valve controls the direction and the flow quantity of hydraulic oil inside an oil box flowing into the hydraulic cylinder according to control signals used for controlling a valve core of the electro-hydraulic proportional valve to move, and the control device calculates a deviation valuebetween a displacement target value and an actual displacement value of the hydraulic cylinder, corrects the deviation value according to the pressure relationship between a first pressure value of arodless cavity of the hydraulic cylinder and a second pressure value of an oil inlet of the electro-hydraulic proportional valve and generates the control signals based on the corrected deviation value. According to the electro-hydraulic control system, method and device, by means of real-time correction on deviation signals, the correction accuracy is improved, displacement deviation caused by load disturbance force is reduced, and the system stiffness is increased.

Description

technical field [0001] The following description relates to an electro-hydraulic control system, method and device. Background technique [0002] The electro-hydraulic proportional valve is a valve that continuously and proportionally controls the flow direction, flow and pressure of the hydraulic system according to the input electrical signal. [0003] figure 1 An electro-hydraulic control system is shown. The displacement sensor 7 installed on the hydraulic cylinder 6 detects the displacement of the piston rod of the hydraulic cylinder 6 in real time, and the displacement feedback signal detected and output by the displacement sensor 7 is converted into U by the analog-to-digital converter 8. f , set the displacement signal U i and the displacement feedback signal U of the hydraulic cylinder 6 f Comparator 1 performs difference calculation to obtain deviation signal E, and the deviation signal E obtains the drive signal U of the electro-hydraulic proportional valve af...

AI Technical Summary

Problems solved by technology

[0004] However, during the working process of the hydraulic cylinder 6, the external load will cause interference force on the piston rod, so that there is a deviation or error in the displacement detected by the displacement sensor 7, that is, there is a large fluctuation in the displacement response under the action of the external load interference force, resulting in the entire The electro-hydraulic control system is not rigid enough, and the external load cannot move accurately

[0005] For example, when the electro-hydraulic proportional valve is used to change the pitch of a wind turbine, since the external load is the blade, the wind changes randomly during the working process of the wind turbine, and the changing wind load will cause a large and variable change in the blade. The interference load force caused by the displacement sensor 7 has a large error in the displacement, and finally the pitch of the wind turbine cannot be accurately realized.

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