Active Control Of Fluid Plusation With Inflow Method

With the development of high precision and low noise of hydraulic system,fluidpulsation has become a key factor restricting the development of hydraulic system.The traditional pulse control method is passive,and the vibration of the system is attenuated by changing the impedance of the system by adding a resistance vibration absorber or a resistive vibration damper.This kind of vibration absorber is often fixed or need to adjust the structure,does not have the ability to adapt.And it has good effect on the reduction of the middle and high frequency of the pressure pulsation,but for the low frequency pulse is often not so good.In recent years,more and more attention has been paid to the active control methods,because of the parameter self adjustment and adaption to different operating conditions.The basic principle of active vibration control is to use the active vibration eliminating valve as the secondary pulse source to produce secondary pulse wave.The secondary pulse wave and the original pulsation of the hydraulic system cancel each other to eliminate the pulsation in the hydraulic system.There are few researches on the active control method to inject small flow oil into the pipeline to make up the value of the pressure fluctuation trough.In this study,the theory and simulation of the active control method with inflow type are studied.Firstly,the feasibility of the active control of fluid pulsation is verified by the indirect experiment and simulation.Then,the paper puts forward a new type of active control system for the pump source pulsation caused by the plunger pump,which uses the combination of the oil pump and the high frequency control valve to inject the oil into the pipeline to generate secondary pulsation.Based on the piezoelectric ceramic material,the design of the vibration eliminating valve of the active vibration control system is presented,which has the characteristics of anti electromagnetic interference,high resolution and high working frequency.The mathematical model is established and it can be found that the response frequency of the valve is above 1000Hz,and the flow characteristics are also satisfied.In the controller algorithm,the Filter-XLMS algorithm with high maturity,good stability and good real-time performance is selected and the algorithm is deduced in detail.The Simulink simulation model of the adaptive feed forward inflow control system for fluid pulsation is established.The simulation results show that the active flow control method can achieve 66.7%ripple attenuation effect,even higher.The influence of.the parameters of the algorithm on the attenuation is analyzed.In addition,the influence of the hydraulic system parameters such as the pump speed and the working pressure of the oil pump on the attenuation effect is also studied.The increase of the pump speed will lead to the decrease of pulsation attenuation rate.and the increase of the working pressure of the oil pump can improve the attenuation rate.In addition,the active flow control method is applied to the high speed on-off valve control system,which attenuates the fluid pulsation caused by the high speed on-off valve.The simulation results show that it has a certain ability to attenuate the periodic pulsation not only the pump pulsation,which provides a basic reference for the active control of a wider range of periodic pulsations.