Digital Speed Control Valve Flow Fluctuation Based On Sliding Mode Control Research And Its Flow Field Analysis

Digital hydraulic technology directly acts on the hydraulic components to achieve accurate control of parameters such as flow,pressure and flow direction of the hydraulic system,thereby avoiding the use of digital-to-analog converters.The hydraulic system equipped with digital hydraulic components can effectively improve the anti-interference ability,response frequency and control accuracy of the hydraulic system to adapt to more complex working environments.Compared with proportional valves and servo valves,digital speed regulating valves have the characteristics of simple structure,reliable working performance,low cost and strong anti-pollution ability.This paper studies the overall structure design,flow fluctuation analysis,flow field distribution in the valve body and the control mode of the drive device to improve the overall performance of the digital speed control valve.According to the working principle of the digital valve,the structural design focuses on modeling and analyzing the opening form of the spool,and the derived mathematical model is imported into Matlab to obtain the corresponding curve of the valve port displacement and area,and the opening form of the valve port and the pressure compensator valve port are determined.In order to select the appropriate drive type,the driving force of the valve spool is calculated and the permanent magnet synchronous motor is modeled.Aiming at the short-term fluctuation phenomenon of the flow rate of the speed control valve under the step pressure difference,the mathematical modeling and analysis are carried out,and the corresponding influencing parameters are composed of differential pressure,spring rate,spring preload,initial opening degree of the pressure compensator and viscous damping coefficient,and the speed regulating valve model is constructed in AMEsim to further optimize the corresponding parameters to obtain the law of the influence of parameter changes on flow fluctuations.According to the selected throttle port form and the design of the flow channel in the valve,the 3D model is drawn,and the inlet channel extraction is imported into Fluent for simulation verification of pressure field and flow velocity field.The permanent magnet synchronous motor acts as a signal receiving device for the drive device of the digital speed control valve,and uses a sliding mode controller with improved approach rate to improve its dynamic performance.According to the above research content,the corresponding experimental bench is designed to verify the relevant parameters of the digital speed control valve,and the control effect of the improved sliding mode controller on the permanent magnet synchronous motor is verified.