A sliding mode control method for electro-hydraulic servo system

Abstract

The invention discloses a sliding-mode control method for an electric-hydraulic servo system. The method comprises the steps that a mathematical model of the electric-hydraulic servo system is established, and then a control strategy of a sliding-mode controller is defined after a boundary layer and an approaching law are improved. According to the sliding-mode control method for the electric-hydraulic servo system, the boundary layer and the approaching law are improved, discontinuous terms are eliminated, the distance from a state point to the sliding-mode surface is decreased, the chattering phenomenon of the sliding-mode controller can be weakened, and the approaching speed is increased; the dynamic response characteristic of the system is improved, the tracking performance of the system is improved, the control accuracy of the system is improved, an input waveform can be better restored, and good control performance of the hydraulic servo system is guaranteed. The sliding-mode control method for the electric-hydraulic servo system has the advantages of being high in servo control accuracy, high in robustness, high in response speed, high in stability and the like.

Description

technical field [0001] The invention belongs to the technical field of electro-hydraulic servo control, and in particular relates to a sliding mode control method of an electro-hydraulic servo system. Background technique [0002] The electro-hydraulic servo system has the advantages of high control precision, fast response, large output power, flexible signal processing, and easy feedback of various parameters. It is most suitable for occasions with large load mass and fast response speed, so it has been widely used in many fields, such as the control of aircraft and ship steering gear, the control of radar and artillery, the position control of machine tool workbench, strip Plate thickness control of rolling mills, electrode position control of electric furnace smelting, control of simulation tables in various aircraft vehicles, control of generator speed, pressure control of material testing machines and other testing machines, etc. Electrohydraulic servo system is a typ...

AI Technical Summary

Problems solved by technology

The electro-hydraulic servo system is a high-rigidity system, which is very sensitive to high-frequency signals and high-gain signals, and is prone to instability under high-frequency signal and high-gain excitation. The traditional sliding mode control method is to increase The method of increasing the gain of the controller can increase the robustness of the controller, and can improve the tracking performance and dynamic response characteristics of the electro-hydraulic servo system, but the traditional sliding mode controller is prone to chattering, which will seriously affect the electro-hydraulic servo. The performance of the system will even seriously distort the system, causing the electro-hydraulic servo system to fail to work

These have severely limited the application of traditional sliding mode control methods in electro-hydraulic servo systems.

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