The variable structure control （VSC） theory is applied to the electro-hydraulic servo system here. The VSC control law is achieved using Lyapunov method and pole placement. To eliminate the chattering phenomena, a s...The variable structure control （VSC） theory is applied to the electro-hydraulic servo system here. The VSC control law is achieved using Lyapunov method and pole placement. To eliminate the chattering phenomena, a saturation function is adopted. The proposed VSC approach is fairly robust to load disturbance and system parameter variation. Since the distortion. including phase lag and amplitude attenuation occurs in the system sinusoid response, the amplitude and phase control （APC） algorithm, based on Adaline neural network and using LMS algorithm, is developed for distortion cancellation. The APC controller is simple and can on-line adjust, thus it gives accurate tracking.展开更多
In this paper, a vector regulating principle of the phase and amplitude control PAC method for three-phase grid-connected inverters is presented.To solve the problem of heavy inrush current and slow dynamic response w...In this paper, a vector regulating principle of the phase and amplitude control PAC method for three-phase grid-connected inverters is presented.To solve the problem of heavy inrush current and slow dynamic response when system starts up, the starting voltage prediction control and the current feed-forward control are proposed and used, which improve the dynamic performance of the system in the PAC.The experimental results carried out on a three-phase grid-connected inverter proved the validity of the proposed method.展开更多
We investigate the optical bistabiiity （OB） in a duplicated two-level system contained in a ring cavity. The atoms are driven by two orthogonally polarized fields with a relative phase. The OB behavior of such a sys...We investigate the optical bistabiiity （OB） in a duplicated two-level system contained in a ring cavity. The atoms are driven by two orthogonally polarized fields with a relative phase. The OB behavior of such a system can be controlled by the amplitude and the relative phase of the coupling field, and it is possible to switch between bistabilitv and multistability by adjusting the relative phase.展开更多
A new beam broadening synthesis technique for Synthetic Aperture Radar(SAR) antenna array, namely Projection Matrix Algorithm(PMA) is presented. The theory of PMA is introduced firstly, and then the iterative renewed ...A new beam broadening synthesis technique for Synthetic Aperture Radar(SAR) antenna array, namely Projection Matrix Algorithm(PMA) is presented. The theory of PMA is introduced firstly, and then the iterative renewed manner is improved to resolve the unbalance problem under amplitude and phase control. In order to validate the algorithm correct and effective, an actual engineering application example is investigated. The beam synthesis results of 1.0~4.5 times broadening under the phase only control and the amplitude and phase control using improved PMA are given. The results show that the beam directivity, the beam broadening, and the side-lobe level requirements were met. It is demonstrated that the improved PMA was effective and feasible for SAR application.展开更多
文摘The variable structure control （VSC） theory is applied to the electro-hydraulic servo system here. The VSC control law is achieved using Lyapunov method and pole placement. To eliminate the chattering phenomena, a saturation function is adopted. The proposed VSC approach is fairly robust to load disturbance and system parameter variation. Since the distortion. including phase lag and amplitude attenuation occurs in the system sinusoid response, the amplitude and phase control （APC） algorithm, based on Adaline neural network and using LMS algorithm, is developed for distortion cancellation. The APC controller is simple and can on-line adjust, thus it gives accurate tracking.
基金supported by the Shanghai Education Committee Scientific Research Subsidization (Grant No.05AZ30)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20060280018)
文摘In this paper, a vector regulating principle of the phase and amplitude control PAC method for three-phase grid-connected inverters is presented.To solve the problem of heavy inrush current and slow dynamic response when system starts up, the starting voltage prediction control and the current feed-forward control are proposed and used, which improve the dynamic performance of the system in the PAC.The experimental results carried out on a three-phase grid-connected inverter proved the validity of the proposed method.
基金supported by the National Natural Science Foundation of China(Nos.61108006 and 11104221)the Scientific Research Program Funded by Shaanxi Provincial Education Department(No.11JK0529)+2 种基金the Natural Science Basis Research Plan in Shaanxi Province of China(No.2010JQ1002)the Doctoral Program Foundation of Institutions of Higher Education of China(No.20106101120020)the support from the Science Foundation of Northwest University(No.10NW14)
文摘We investigate the optical bistabiiity （OB） in a duplicated two-level system contained in a ring cavity. The atoms are driven by two orthogonally polarized fields with a relative phase. The OB behavior of such a system can be controlled by the amplitude and the relative phase of the coupling field, and it is possible to switch between bistabilitv and multistability by adjusting the relative phase.
文摘A new beam broadening synthesis technique for Synthetic Aperture Radar(SAR) antenna array, namely Projection Matrix Algorithm(PMA) is presented. The theory of PMA is introduced firstly, and then the iterative renewed manner is improved to resolve the unbalance problem under amplitude and phase control. In order to validate the algorithm correct and effective, an actual engineering application example is investigated. The beam synthesis results of 1.0~4.5 times broadening under the phase only control and the amplitude and phase control using improved PMA are given. The results show that the beam directivity, the beam broadening, and the side-lobe level requirements were met. It is demonstrated that the improved PMA was effective and feasible for SAR application.
