A multi-domain nonlinear dynamic model of a proportional solenoid valve was presented.The electro-magnetic,mechanical and fluid subsystems of the valve were investigated,including their interactions.Governing equation...A multi-domain nonlinear dynamic model of a proportional solenoid valve was presented.The electro-magnetic,mechanical and fluid subsystems of the valve were investigated,including their interactions.Governing equations of the valve were derived in the form of nonlinear state equations.By comparing the simulated and measured data,the simulation model is validated with a deviation less than 15%,which can be used for the structural design and control algorithm optimization of proportional solenoid valves.展开更多
Based on the Ricatti technique, the methodology for preventing the limit cycle accomplished by adding a control function to the original equation of wing rock motion is presented in this paper. To analyze the state va...Based on the Ricatti technique, the methodology for preventing the limit cycle accomplished by adding a control function to the original equation of wing rock motion is presented in this paper. To analyze the state variables of the system, the complete set of nonlinear equations of motion including an effective linear control function was solved for A-4D and Mig-21 Aircraft. The roll angle responding to the linear control function for both models was estimated when the systems were tested under different damping ratios. The numerical re- suits show that a linear control function including both the roll attitude and the roll rate is sufficient to suppress the wing rock motion with an acceptable error in desired time. A good agreement between the numerical results and the published work is obtained for the limit cycle oscillation existence at different damping ratios.展开更多
In this paper we develop a variational theory to study the dynamic properties of ultracold Bose gas ina funnel external potential.We obtain one-dimensional nonlinear equation which describes the dynamics of transverse...In this paper we develop a variational theory to study the dynamic properties of ultracold Bose gas ina funnel external potential.We obtain one-dimensional nonlinear equation which describes the dynamics of transversetight confined bosonic gas from three-dimension to one-dimension,and find one-dimensional s-wave scattering lengthwhich depends on the shape of transverse confining potential.If the funnel trapping potential is strong enough at zerotemperature,all transverse excitations are frozen.We find the dynamic equation which describes the Tonks-Girardeaugas and present a qualitative analysis of the experimental accessibility of the Tonks-Girardeau gas with funnel-trappedalkalic atoms.展开更多
We consider the nonlinear functional dynamic equation （p（t）[（r（t）x^△（t））^△]γ）^△＋q（t）f（x（τ（t））） =0, for t≥t0,on a time scale T, where γ〉 0 is the quotient of odd positive integers, p, r, τ- ...We consider the nonlinear functional dynamic equation （p（t）[（r（t）x^△（t））^△]γ）^△＋q（t）f（x（τ（t））） =0, for t≥t0,on a time scale T, where γ〉 0 is the quotient of odd positive integers, p, r, τ- and q are positive rd-continuous functions defined on the time scale 1F, and lirut→∞ τ（t） = ∞. The main aim of this paper is to establish some new sufficient conditions which guarantee that the equation has oscillatory solutions or the solutions tend to zero as →∞ τ. The main investigation depends on the Riccati substitution and the analysis of the associated Riccati dynamic inequality. Our results extend, complement and improve some previously obtained ones. In particular, the results provided substantial improvement for those obtained by Yu and Wang [J Comput Appl Math, 225 （2009）, 531-540]. Some examples illustrating the main results are given.展开更多
By considering the static voltage characteristic of the load, we propose a WAMS/SCADA mixed nonlinear method to estimate the voltage of unobservable buses caused by topology change or phasor measurement unit (PMU) mal...By considering the static voltage characteristic of the load, we propose a WAMS/SCADA mixed nonlinear method to estimate the voltage of unobservable buses caused by topology change or phasor measurement unit (PMU) malfunction in a power system. By modeling the load characteristic with data from SCADA, we employed the Gauss-Seidel method to solve the nonlinear equations and estimate the voltage of unobservable buses with the high precision voltages of neighboring buses measured by a PMU. Simulations were carried out on the IEEE 39-bus system, and the results show that this novel method can dynamically and accurately trace the variation of the voltage phasor of the unobservable buses.展开更多
基金Project(2008ZHZX1A0502) supported by the Independence Innovation Achievements Transformation Crucial Special Program of Shandong Province,China
文摘A multi-domain nonlinear dynamic model of a proportional solenoid valve was presented.The electro-magnetic,mechanical and fluid subsystems of the valve were investigated,including their interactions.Governing equations of the valve were derived in the form of nonlinear state equations.By comparing the simulated and measured data,the simulation model is validated with a deviation less than 15%,which can be used for the structural design and control algorithm optimization of proportional solenoid valves.
文摘Based on the Ricatti technique, the methodology for preventing the limit cycle accomplished by adding a control function to the original equation of wing rock motion is presented in this paper. To analyze the state variables of the system, the complete set of nonlinear equations of motion including an effective linear control function was solved for A-4D and Mig-21 Aircraft. The roll angle responding to the linear control function for both models was estimated when the systems were tested under different damping ratios. The numerical re- suits show that a linear control function including both the roll attitude and the roll rate is sufficient to suppress the wing rock motion with an acceptable error in desired time. A good agreement between the numerical results and the published work is obtained for the limit cycle oscillation existence at different damping ratios.
基金Supported by National Natural Science Foundation of China under Grant No.10647144Natural Science Foundation under Grant GK0513102Doctoral Special Fund of Yangzhou University
文摘In this paper we develop a variational theory to study the dynamic properties of ultracold Bose gas ina funnel external potential.We obtain one-dimensional nonlinear equation which describes the dynamics of transversetight confined bosonic gas from three-dimension to one-dimension,and find one-dimensional s-wave scattering lengthwhich depends on the shape of transverse confining potential.If the funnel trapping potential is strong enough at zerotemperature,all transverse excitations are frozen.We find the dynamic equation which describes the Tonks-Girardeaugas and present a qualitative analysis of the experimental accessibility of the Tonks-Girardeau gas with funnel-trappedalkalic atoms.
基金supported by King Saud University,Dean-ship of Scientific Research,College of Science Research Centre
文摘We consider the nonlinear functional dynamic equation （p（t）[（r（t）x^△（t））^△]γ）^△＋q（t）f（x（τ（t））） =0, for t≥t0,on a time scale T, where γ〉 0 is the quotient of odd positive integers, p, r, τ- and q are positive rd-continuous functions defined on the time scale 1F, and lirut→∞ τ（t） = ∞. The main aim of this paper is to establish some new sufficient conditions which guarantee that the equation has oscillatory solutions or the solutions tend to zero as →∞ τ. The main investigation depends on the Riccati substitution and the analysis of the associated Riccati dynamic inequality. Our results extend, complement and improve some previously obtained ones. In particular, the results provided substantial improvement for those obtained by Yu and Wang [J Comput Appl Math, 225 （2009）, 531-540]. Some examples illustrating the main results are given.
基金Project supported by the National Natural Science Foundation of China (Nos. 50507018, 50595414, 50677062, and 60421002)the National Basic Research Program (973) of China (No. 2004CB217902)+1 种基金the National Key Technologies Supporting Program of Chinaduring the 11th Five-Year Plan Period (No. 2006BAA02A01)theKey Grant Project of MOE of China (No. 305008)
文摘By considering the static voltage characteristic of the load, we propose a WAMS/SCADA mixed nonlinear method to estimate the voltage of unobservable buses caused by topology change or phasor measurement unit (PMU) malfunction in a power system. By modeling the load characteristic with data from SCADA, we employed the Gauss-Seidel method to solve the nonlinear equations and estimate the voltage of unobservable buses with the high precision voltages of neighboring buses measured by a PMU. Simulations were carried out on the IEEE 39-bus system, and the results show that this novel method can dynamically and accurately trace the variation of the voltage phasor of the unobservable buses.
