Research On Nonlinear Modelling Of A Small High Speed On-off Digital Valve

Digital hydraulic technology has become a hot spot for scholars in the field of hydraulics for its advantages of energy saving,good fault tolerance,strong interchangeability,cost effective and strong resistance to pollution.General digital valve is characterized with small size,a single valve is difficult to meet the demand of system flow,usually multiple valves used in parallel,the miniaturization of the digita l valve to improve the system function weight ratio,reduce the volume of manifold blocks and reducing the installation space of the valve is of great significance,therefore,the miniaturization of the digital valve research become the important content in the study of digital hydraulic technology.The working process of the digital valve involves the coupling of electromagnetic field,flow field,temperature field,dynamics and other physical fields,which has strong nonlinearity,but not in the most of today’s research on the comprehensive consideration,therefore,in this paper,a high precision nonlinear modeling method of small high speed digital valve based on BP neural network is proposed,and the key parameters of electromagnetic field,flow field,temperature field and dynamic model are studied:(1)Modeling and analysis of key parameters of electromagnetic field.The electromagnetic field mechanism of small high-speed on-off digital valve is modeled,and the electromagnetic force test bench is built.The electromagnetic force and current variation law are analyzed by combining theory and experiment.Based on BP neural network,the accurate flow model and hydrodynamic model are established,which lays the foundation for the establishment of the nonlinear model of small high speed digital valve.(2)Modeling and analysis of key parameters of flow field.Choose appropriate flow field control,set up,including flow rate,fluid power and damping for ce,mechanism of flow field model,structures,multifunctional test-bed flow field parameters,the paper proposes a new method for measuring flow rate and fluid dynamics,and get a different valve core displacement and pressure difference of flow rate and fluid dynamic change rule,and the mechanism of flow field model of the obtained results were analyzed.Based on BP neural network,the accurate flow model and hydrodynamic model are re-established,which lays the foundation for establishing the nonlinear model of small high-speed on-off digital valve.(3)Modeling and analysis of key parameters of flow field.Choose appropriate flow field control,set up,including flow rate,fluid power and damping for ce,mechanism of flow field model,structures,multifunctional test-bed flow field parameters,the paper proposes a new method for measuring flow rate and fluid dynamics,and get a different valve core displacement and pressure difference of flow rate and fluid dynamic change rule,and the mechanism of flow field model of the obtained results were analyzed.Based on BP neural network,the accurate flow model and hydrodynamic model are re-established,which lays the foundation for establishing the nonlinear model of small high-speed on-off digital valve.(4)Research on nonlinear model of whole valve.With the help of Adams(automatic dynamic analysis of mechanical systems)dynamic analysis software,the dynamic model of small high-speed on-off digital valve is established to more truly simulate the motion state of the moving parts in the valve.Based on the physical models of electromagnetic field,flow field and temperature field,the nonlinear model of the whole valve is obtained.(5)The dynamic and static characteristics of the small high-speed digital valve were tested to verify the accuracy of the nonlinear model.The results show that the proposed nonlinear model can accurately simulate the dynamic and static characteristics of the valve.