Dynamic characteristics and tracking precision are studied in the photoelectric tracking system and a linear active disturbance rejection control( LADRC) scheme is proposed for position loop. A current and speed contr...Dynamic characteristics and tracking precision are studied in the photoelectric tracking system and a linear active disturbance rejection control( LADRC) scheme is proposed for position loop. A current and speed controller is designed by a transfer function model,which is obtained by adaptive differential evolution. Model error,friction and nonlinear factor existing in position loop are treated as ‘disturbance',which is estimated and compensated by generalized proportional integral( GPI)observer. Comparative results are provided to demonstrate the remarkable performance of the proposed method. It turns out that the proposed scheme is successful and has superior features,such as quick dynamic response,low overshoot and high tracking precision. Furthermore,with the proposed method,friction is suppressed effectively.展开更多
To realize the sustainable development of the economy of West China is not merely a great economic problem, butalso a great national problem and political issue. The economic activity is a practical activity for the e...To realize the sustainable development of the economy of West China is not merely a great economic problem, butalso a great national problem and political issue. The economic activity is a practical activity for the economic subject. Theeconomic development view, values, and the natural view of the economic subject determine the choice of the behavior of themain body in the economic activity. Only the behavior of the economic subject according with its demands could make theeconomy of west China have a sustainable development. Therefore, establishing the development view, the values and naturalview of the economic subject for sustainable development becomes a realistic problem that is worth of thinking.展开更多
Modal decomposition technology is an effective method to study the mode characteristics of laser beam in few-mode fibers.However,certain types of eigenmodes in the fiber can cause focal shift and affect the accuracy o...Modal decomposition technology is an effective method to study the mode characteristics of laser beam in few-mode fibers.However,certain types of eigenmodes in the fiber can cause focal shift and affect the accuracy of modal decomposition.This article focuses on the influence of the focal shift of Laguerre-Gaussian mode and Linear Polarization mode on modal decomposition,and the research is based on correlation filter and the optimization algorithm of focal shift.The two-step ABCD algorithm is used to simulate and analyze the focal shift phenomenon of the two kinds of eigenmodes and the error influence of focal shift on the mode decomposition;Meanwhile,an iterative algorithm based on Fresnel diffraction is proposed to numerically calculate the light field distribution in focal plane to avoid the influence of focal shift errors.The focal shift analysis and its optimization algorithm make the modal decomposition technology be applicable to engineering applications.展开更多
基金Supported by the National High Technology Research and Development Programme of China(No.2015AA8082065)the National Natural Science Foundation of China(No.61205143)
文摘Dynamic characteristics and tracking precision are studied in the photoelectric tracking system and a linear active disturbance rejection control( LADRC) scheme is proposed for position loop. A current and speed controller is designed by a transfer function model,which is obtained by adaptive differential evolution. Model error,friction and nonlinear factor existing in position loop are treated as ‘disturbance',which is estimated and compensated by generalized proportional integral( GPI)observer. Comparative results are provided to demonstrate the remarkable performance of the proposed method. It turns out that the proposed scheme is successful and has superior features,such as quick dynamic response,low overshoot and high tracking precision. Furthermore,with the proposed method,friction is suppressed effectively.
文摘To realize the sustainable development of the economy of West China is not merely a great economic problem, butalso a great national problem and political issue. The economic activity is a practical activity for the economic subject. Theeconomic development view, values, and the natural view of the economic subject determine the choice of the behavior of themain body in the economic activity. Only the behavior of the economic subject according with its demands could make theeconomy of west China have a sustainable development. Therefore, establishing the development view, the values and naturalview of the economic subject for sustainable development becomes a realistic problem that is worth of thinking.
基金supported by the Key Research Program of Frontier Sciences of Chinese Academy of Sciences(No.QYZDB-SSW-SLH014)the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2018248/Y80139C)+1 种基金the Xuguang Talen of Changchun Institute of Optics,Fine Mechanics and Physics of Chinese Academy of Sciences(No.201900X)the Foundation of State Key Laboratory of Laser Interaction with Matter(No.SKLLIM1704)。
文摘Modal decomposition technology is an effective method to study the mode characteristics of laser beam in few-mode fibers.However,certain types of eigenmodes in the fiber can cause focal shift and affect the accuracy of modal decomposition.This article focuses on the influence of the focal shift of Laguerre-Gaussian mode and Linear Polarization mode on modal decomposition,and the research is based on correlation filter and the optimization algorithm of focal shift.The two-step ABCD algorithm is used to simulate and analyze the focal shift phenomenon of the two kinds of eigenmodes and the error influence of focal shift on the mode decomposition;Meanwhile,an iterative algorithm based on Fresnel diffraction is proposed to numerically calculate the light field distribution in focal plane to avoid the influence of focal shift errors.The focal shift analysis and its optimization algorithm make the modal decomposition technology be applicable to engineering applications.
