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Multiple equilibria of cross-equatorial Inertial jets

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Science China Earth Sciences 2007年第1期50卷 153-160页

作者： CHAO JiPing1,2 & LIU Fei3.4 1 National Marine Environmental Forecasting Center, Beijing 100081, China 2 The First Institute of oceanography ,SOA, qingdao 266060, China 3.Key Laboratory Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric physics, Chinese Academy of Sciences, Beijing 100029, China 4 Graduate {3. of Chinese Academy of Sciences, Beijing 10003., China National Marine Environmental Forecasting Center Beijing 100081 China The First Institute of oceanography SOA Qingdao 266060 China Key Laboratory Regional Climate-Environment for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Graduate university of Chinese Academy of Sciences Beijing 100039 China

Based on the developed Anderson and Moore's theory about cross-equatorial inertial jets and a nonlinear equivalence shallow water model, new universal functions are determined by the characters of the vortical large-scale air flow (atmosphere) or ocean current (ocean) related to the jet, then the potential vorticity and energy conservation equations along the streamline in the cross-equatorial in-ertial jets can be obtained. Because the governing equations are nonlinear, some limited multiple equi-libria of cross-equatorial inertial jets may exist. According to the character of large-scale air flow or ocean current outside the jets, the existent criterion for multiple eqnilibria in cross-equatorial inertial jets is discussed, and two examples for multiple equilibia of nonlinear governing equations are given.

关键词： multiple equilibria cross-equatorial inertial jets the potential vorticity energy conservation.

Chattering-free Finite-time Tracking Control Algorithms with Variable Structure for Mobile Robots

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Chattering-free Finite-time Tracking Control Algorithms with...

Virtual-Leader-follower Structure and Finite-time Controller based Cooperative Control of Multiple Autonomous Underwater Vehicles

第24届中国控制与决策会议

作者： ZHOU Zhong-Hai 1, 2, 3.YUAN Jian 2, 3. ZHANG Wen-Xia 4 ZHAO Jin-Ping 1 (1. College of Physical and Environmental oceanography, Ocean university of China, qingdao, 2661002. Shandong Provincial Key Laboratory of Ocean Environment Monitoring Technology, qingdao, 2660013. Institute of Oceanographic Instrumentation of Shandong Academy of Science, qingdao, 266001 4.Mechanical & Electrical Engineering department, Qindao College, qingdao Shandong, 266016)

The trajectory-tracking problem for mobile robot is considered. A compound finite-time tracking control linearization algorithm base on feedback linearization and variable structure is proposed, and the reaching-control law is used to drive the steering angle trajectory with large inertial error exponentially toward the given switching surface neighborhood. When the steering angle trajectory is inside the neighborhood, the chattering-free control law based on continuous state-feedback drives the trajectory to the switching surface precisely while converting the original nonlinear system into a reduced system;state-feedback control law for the reduced system is then designed to stabilize the position error in finite time. Numerical simulations show the desired trajectory is attained fully in finite-time without chattering.

关键词： Mobile robot trajectory tracking finite time variable structure chattering-free

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Virtual-Leader-follower Structure and Finite-time Controller...

Formation of the thermal-driven boundary jet in an f-plane mesoscale basin

第24届中国控制与决策会议

The formation control for large-scale multiple autonomous underwater vehicles is investigated. A formation control scheme to combinate leader-follower with virtual structure is introduced;AUVs with underwater communication rage constraints are divided into some clusters according to their relative postions in space, and leaders in all clusters can track their desired trajectories based on virtual structure;followers within all clusters follow the corresponding leader as their desired tracking trajectory. We realize the larege-scale formation control with the proposed formation scheme and the finite-time controller proposed in our previous work. Numerical simulation results show the effectiveness of the control strategy.

关键词： Autonomous Underwater Vehicle Large-scale Formation Control Virtual-leader-follower Hierarchical Structure Feedback Linearization, Finite time

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Science China Earth Sciences 2008年第1期51卷 152-160页

作者： FENG LiCheng1,2 & CHAO JiPing3.4 1 State Key Laboratory of Numerical Modeling for Atmospheric Science and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric physics, Chinese Academy of Sciences, Beijing 100029, China 2 Graduate university of the Chinese Academy of Sciences, Beijing 100049, China 3.National Marine Environment Forecast Center, Beijing 100081, China 4 First Institute of oceanography, State Oceanic Administration, {3. 266061, China State Key Laboratory of Numerical Modeling for Atmospheric Science and Geophysical Fluid Dynamics LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Graduate university of the Chinese Academy of Sciences Beijing 10 National Marine Environment Forecast Center Beijing 100081 China First Institute of oceanography State Oceanic Administration Qingdao 266061 China

The paper adopts an f-plane quasi-geostrophic inertial model without linearization to investigate the perturbation temperature, boundary jet and upwelling (downwelling) in an idealized rectangular basin, under the consideration of west side friction layer and heat conservation. There is net heat input on the upper surface and equal quality heat dissipation on the west boundary, and without heat exchange on other boundaries, then the heat is conservation in the whole basin. Results show that there is thermal front due to denseness of the perturbation temperature in the west side boundary, the perturbation pressure and flow field are reversal on the upper layer and bottom layer. On the bottom layer, the west coastal current is northward, and the maximum perturbation pressure center is on the west, however, on the upper layer, the east coastal current is southward, and the maximum perturbation pressure center is on the east. There is strong vertical flow in narrow western boundary layer, and also in the central zone. The effect of different upper thermal forcings is also studied, and it can be concluded that there is always temperature denseness and boundary jet near the west boundary, and the appearance of flow field reversal, but the distribution of vertical flow is rather different.

关键词： boundary jet vertical flow thermal front thermal-driven heat conservation

Application of nonlinear optimization method to sensitivity analysis of numerical model

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Progress in Natural Science:Materials International 2004年第6期 84-87页

作者： XU Hui 1,MU Mu 1 * and LUO Dehai 2(1. LASG,Institute of Atmospheric physics,Chinese Academy of Sciences,Beijing 100029,China 2. department of Atmosphere Sciences,Ocean university of China,{3. 266003.China) LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China department of Atmosphere Sciences Ocean University of China Qingdao 266003 China

A nonlinear optimization method is applied to sensitivity analysis of a numerical model. Theoretical analysis and numerical experiments indicate that this method can give not only a quantitative assessment whether the numerical model is able to simulate the observations or not,but also the initial field that yields the optimal simulation. In particular,when the simulation results are apparently satisfactory,and sometimes both model error and initial error are considerably large,the nonlinear optimization method,under some conditions,can identify the error that plays a dominant role.

关键词： sensitivity analysis nonlinear optimization adjoint method numerical model.

Inversion of acoustic mode coupling coefficient matrix

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Chinese Journal of Acoustics 2007年第2期26卷 118-126页

作者： LIU Jinzhong WANG Ning GAO Dazhi department of physics Weifang University Weifang 261061 department of physics Ocean University of China Qingdao 266071

It is found that the normal mode amplitude time series consist of multi-frequency component by analyzing the structure of acoustical signal when internal wave propagation ex- ists, and each frequency is the product of internal wave speed and the normal mode wave number difference between acoustical receivers and source. The amplitude of each component is proportional to the acoustic mode coupling coefficient. The structure of the normal mode coefficient time series is still complex even the internal waves do not reshape when they propagate from the acoustical receivers to the source. A method is presented to compute the AMCCM by the feature of IWs＇ motion and the relation between the AMCCM and the acoustical signal fluctuation amplitude. The lWs data measured in the 2001 Asia experiment （ASIAEX2001） is used to check the accuracy of this method by numerical simulation. It is show that the method is accurate to compute the AMCCM.

关键词： normal mode time series numerical simulation coupling coefficient wave propagation internal waves wave speed

A baroclinic typhoon model with a moving multi-nested grid and variational adjustment initialisationI. Numerical method

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Acta Oceanologica Sinica 1999年第4期18卷 191-201页

作者： Wu Huiding Yang Xuelian Bai Shan and Li Guoqing 1. National Marine Environmental Forecasting Centre, State Oceanic Administration, Beijing 100081, China 2. department of physics and Physical oceanography, Memorial {3. of Newfoundland, St. John’ s, National Marine Environmental Forecasting Centre Beijing 100081 China department of physics and Physical oceanography Memorial University of Newfoundland St. John's NF A1B 3X7 Canada

A baroclinic typhoon model with a moving multi--nested grid is applied in marine environmental forecasts. This paper describes the numerical methods of the model including governing equations, finite differencing, spl... 详细信息

关键词： Typhoon model 3.dimensional baroclinic numerical method moving nested grid

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光焦度的线性测量原理

物理实验 2001年第6期21卷 39-40页

作者：刘兵刘光兰青岛大学物理系山东青岛266071

介绍了将测光焦度参量化为测线性位移参量的方法

关键词：光焦度透镜线性测量自动化测量物理实验

A correction on two dimensional KdV equation with topography

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Progress in Natural Science:Materials International 2004年第7期 94-96页

作者： XU Zhaoting 1*, Efim PELINOVSKY 2, SHEN Guojin 1 and Tapiana TALIPOVA 2(1. Institute of Physical oceanography and Physical oceanography Laboratory, Ocean university of China, {3. 266003. China 2. Institute of Applied physics, Russian Academy of Sciences, Nizhny Novgorod 603.50, Russia) Institute of Physical oceanography and Physical oceanography Laboratory Ocean University of China Qingdao 266003 China Institute of Applied physics Russian Academy of Sciences Nizhny Novgorod 603950 Russia

The correction on the 2D KdV equation derived by Djordjevic and Redekopp is presented. A lapsus calami in the 2D KdV equation is removed by means of the conservation principle of the energy flux in a wave ray tube. The results show that the coefficient of the third term in the inhomogeneous term of 2D KdV equation in the paper of Djordjevic and Redekopp is 2, instead of 3.

关键词： D KdV equation soliton wave ray tube correction.