无人机组网技术在海洋观测中的应用研究   总被引：1，自引：0，他引：1  

徐栋  杨敏  王新胜  孙昕雨 《海洋科学》2018,42(1):45-51

为了应对海洋多个观测平台间组网通信的迫切需求,作者从体系架构和通信链路等多个层面对无人机组网通信技术的研究进展进行总结,并关注了军用和搜救方面的特殊应用。最后结合实际项目中多机协同海洋观测的具体场景,分析了现有无人机组网通信技术的成果和不足,指出了未来的发展方向。  相似文献   

Information fusion model-free adaptive control algorithm and unmanned surface vehicle heading control     

《Applied Ocean Research》2019

Based on the model-free adaptive control (MFAC) theory, the heading control problem of unmanned surface vehicles (USVs) with uncertainties is explored. First, as a USV’s heading subsystem does not satisfy the quasilinear assumption of the MFAC theory, a new type of input and output information fusion MFAC, i.e., the IOIF–MFAC algorithm is proposed. The novel algorithm proposed herein renders the MFAC theory applicable to the heading control of USVs. Next, the input and output information of the heading subsystem, namely the rudder angle and heading angle, are combined, and the data model of the heading subsystem is subsequently deduced using a compact format dynamic linearization method. Based on which, the stability of the control system is proved. Finally, the effectiveness and practicability of the IOIF–MFAC algorithm are verified by simulation and field experiments through the “Dolphin IB” test platform developed by our group.  相似文献   

一种基于超短基线定位的便携式AUV回坞导航方法          下载免费PDF全文

裘天佑  李一平 《海洋技术学报》2019,38(2)

自主水下机器人(AUV)对接技术是目前水下机器人的研究热点,精确可靠的AUV的回坞导航是实现对接的关键技术。对于追求轻便的便携式AUV的对接系统,考虑到便携式AUV的搭载能力有限又需要足够的定位精度用于对接,提出了一种基于超短基线(USBL)定位的回坞导航方法,该方法让AUV只需装载电子罗盘和水声应答器就能完成精确的回坞定位。根据导航方法的特点,设计了一种改进的扩展卡尔曼滤波算法,其优点是能在处理滞后的USBL数据的同时动态估算海流、更新状态方程以消除海流造成的定位误差。通过湖试和大量仿真实验,验证了定位算法在海流影响下的定位性能。  相似文献   

Compression–shear coupling rheological constitutive model of the deep-sea sediment     

Feng Xu  Jie Zhang  Wenbo Ma 《Marine Georesources & Geotechnology》2018,36(3):288-296

In deep-sea mining engineering, the compression–shear coupling effect of the sediment on the moving tracked mining vehicle must be considered, since it is proved to be existing in compression–shear creep test of the sediment simulant. Based on the endochronic theory, the compression–shear coupling rheological model is established by the definition of intrinsic time and calculation of deviatoric tensor, where the coupling rheological parameters can be obtained by the compression–shear creep test. For simulating sinkage and traction force of the moving tracked mining vehicle, the compression–shear coupling rheological model as well as compressive rheological model and direct shear rheological model (regardless of coupling rheological effect) is programmed and introduced into RecurDyn software (with only traditional elastic–plastic constitutive model) for comparison. Research results show that the sinkage is the largest, and the traction force is the smallest under the compression–shear coupling rheological model, which could better reflect the worse working situation. The compression–shear coupling rheological model could provide theoretical basis for optimal design and safety assessment of the tracked mining vehicle.  相似文献   

Trajectory-cell based method for the unmanned surface vehicle motion planning     

《Applied Ocean Research》2019

A trajectory-cell based method was proposed for unmanned surface vehicle (USV) motion planning to combine the expression of the dynamic constraints and the discretization of the search space. The dynamic constraints were expressed by the USV trajectories produced by the mathematical model. The search space was performed by the discretization rules with the consideration of the path continuity, the search convenience and the maneuvering simplification. Therefore, the trajectory-cells were the discretized trajectories, which made the search space meet the USV dynamic constraints, and guaranteed the final spliced path continuous. After abstracting the characteristics of those cells, the available waypoints and headings were represented as the search indexes. Finally, a trajectory-cell based path searching strategy was proposed by determining the cost function of the A* algorithm. The results showed that the proposed algorithm can plan a practical motion path for the USV.  相似文献   

Layered berthing method and experiment of unmanned surface vehicle based on multiple constraints analysis     

《Applied Ocean Research》2019

Considering the dynamic changes of unmanned surface vehicle (USV) in berthing tasks, the planning and control modes are divided into two phases: the remote phase and the terminal phase. According to the main influencing factors of the two phases, an improved artificial potential field method is proposed to complete autonomous berthing trajectory planning based on the analysis of environment constraint, berth point constraint and USV’s dynamics constraint. Combining with the dynamic characteristics and control objectives at different phases of berthing and analyzing the fuzzy rule regulation strategy of USV’s heading and speed control, an improved adaptive fuzzy PID control method is proposed to solve the control problem of USV, which is influenced by weak maneuver, large disturbance, limited water area and strong shore effect. Finally, the comparative test of berthing simulation verifies the superiority of the proposed control method. The autonomous berthing field experiment is completed based on the "Dolphin-I" small USV. It verifies the validity and feasibility of the proposed autonomous berthing method.  相似文献   

Application of particle filter combined with extended Kalman filter in model identification of an autonomous underwater vehicle based on experimental data     

《Applied Ocean Research》2019

This study proposes a method for identification of the nonlinear dynamic model of an AUV while some states are unmeasured; hence, it concentrates on a nonlinear “state and parameter estimation” issue. In this method, a local linearization is used for solving the nonlinear dynamics based on the extended Kalman filter (EKF), and a particle filter (PF) is used to minimize errors and variances of the nonlinear system. In other words, the PF is combined with the EKF in the form of the extended Kalman particle filter (EKPF). The EKPF method is independent of the initial values and satisfies the limits of the parameters and also the assumption that the hydrodynamic coefficients are constant. Hence, it is shown when the ranges or signs of some parameters are known, the EKPF is a more accurate estimator than the EKF. Moreover, a new simulation is done using the model estimated by the EKPF and the results are compared and validated with the measured data of a new experimental test. It is shown that the obtained model can predict the trajectory path with the total normalized root-mean-square error (NRMSE) of 14% and the surge mean speed with the NRMSE of 5%; and it describes the 6DOF motion of the AUV more accurate than the EKF model.  相似文献   

Numerical prediction of the effective wake profiles of a high-speed underwater vehicle with contra-rotating propellers     

《Applied Ocean Research》2019

A numerical method is proposed to predict the effective wake profiles of high speed underwater vehicles propelled by contra-rotating propellers (CRPs), in which the hydrodynamic effects of the CRPs are simulated by distributed body forces. First, Reynolds-averaged Navier-Stokes (RANS) simulations are conducted for identical body-force distributions in open-water and self-propulsion conditions. The effective wake profiles at the CRP disks are then obtained by subtracting the velocities induced by the body forces in the open water from those induced by the body forces in the self-propulsion condition. The effective wake profiles were then predicted for a generic underwater vehicle with an established CRP design. Next, the hydrodynamic performance of the CRPs in the effective wake was computed using an in-house vortex-lattice code. The potential-flow results agree well with those provided by the RANS simulation under the self-propulsion condition, indicating that the proposed method can predict the effective wake profiles for CRPs with reasonable accuracy. The influences of different wake components on the blade forces were investigated, determining that for CRPs, and especially for the aft propeller, the circumferential wake cannot be neglected in the design.  相似文献   

面向对象的无人机遥感影像海岸线提取方法研究     

麻德明  刘焱雄  金永德  程宝权 《海洋科学》2020,44(10):46-51

针对海岸线区域地形复杂和卫星遥感影像分辨率的不足,精度难以满足大比例尺成图要求,以及常规解译方法的局限性,选取青岛小岛湾海岸线为研究区,以无人机（UAV）遥感影像为基础数据,提出一种面向对象的海岸线提取方法,结合现场实测验证,开展了人工海岸线和砂质海岸线识别的应用实验。结果表明：人工海岸线和砂质海岸线概率边缘指数（PRI）分别为0.97和0.88,边缘定位误差（BDE）分别为4.33和2.84,提取的人工海岸线和砂质海岸线与实测海岸线结果整体上匹配较好,仅在局部细微处存在微小差异。本文提出的方法可快速有效地获取海岸线信息,其精度能够满足海岸线动态变化监测的需求,可在海岸线资源管理中推广应用。  相似文献   

多旋翼单镜头无人机不同航线规划的三维建模方法评述     

王云川  段平  李佳  姚永祥  成李博 《测绘通报》2020,(3):105-108

选用多旋翼单镜头无人机作为航摄设备,对同一建筑物规划交叉航线、全航线及5架次模拟航线,构建该建筑物的实景三维模型,并从模型完整性和地面控制点点位精度两个方面对3种不同航线三维建模方法进行评述。结果表明：①交叉航线建模方法控制点点位精度高,但模型完整性差;②全航线建模方法控制点点位精度高,模型完整性较高;③5架次模拟航线建模方法控制点点位精度略低,模型完整性最好。  相似文献