共查询到19条相似文献，搜索用时 93 毫秒
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无人船是海洋技术发展的产物,作为一种新型技术手段目前已在海洋调测和防务领域广泛应用.本文从无人船系统的组成、应用领域和发展现状出发,归纳总结无人船的关键技术,并研究其发展趋势.作为一种水面机动载体,无人船关键技术包括特型平台设计技术、运动控制技术和通信技术3个方面,其核心是围绕任务内容、载荷原理、使用环境特点,以应用设计、功能开发为主体的系统集成和应用.现阶段无人船主要作为传统海上工作方法的补充,在遵守、参照现有各种法规、技术标准要求的前提下,搭载已成型的船用任务载荷,按照载人船舶的作业模式、施工惯例投入各种应用.未来随着材料技术、人工智能、通信技术的发展,以及相关政策、法规的建立、健全,无人船将逐步成为一种独立的技术手段,形成一系列新的作业模式和技术方法. 相似文献
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为解决无人船适用海商法存在的问题,促进我国无人船海上运输产业的健康可持续发展,文章从法理的角度阐释国际海事委员会无人船调查问卷中无人船的法律地位、船长和船员的认定以及无人船的碰撞责任,提出无人船适用海商法存在不确定性风险;在海商法领域,无人船的法律地位认定、船长和船员的识别以及船舶碰撞责任的适用仍存在问题,解决上述问题的有效路径是明确无人船的法律地位、将岸基控制人员识别为船员、采用过错责任原则认定无人船的碰撞责任以及合理分配船东与生产者之间的碰撞责任,以合理规避无人船的风险。 相似文献
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针对含有模型参数不确定性、外界干扰与抖振现象的无人船编队问题，提出了一种基于扰动观测器的非奇异模糊终端滑模编队控制方法。首先，将领航者–跟随者与人工势场法相结合，获得无人船的编队构型并保证无碰撞现象；其次，基于 Lyapunov 能量函数设计出模糊控制规则，消除了控制器中的抖振问题； 进而，提出了一种扰动观测器来补偿未知动态和外界干扰，增强了系统的鲁棒性和稳定性。通过理论分析和仿真结果验证了所提控制方法的有效性。基于所设计的编队控制方法，无人船最终可形成期望的编队构型。 相似文献
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针对多礁石、渔船等障碍物的近海复杂环境下的一些应用,提出了一种基于有限状态机(finite-state machine,FSM)模型的无人船(unmanned surface vehicle,USV)局部转向避碰路径规划算法。首先,基于速度障碍法和障碍物区域分层方法,获取无人船固定航速条件下的航向角约束解析结果。然后,基于该约束条件及障碍物探测情况设计FSM的有限状态及执行动作和状态迁移条件,其中,通过转向控制实现向目标位点或缓冲位点进行导航的状态为FSM的2个重要状态。最终通过FSM的执行实现局部转向避碰路径规划。仿真结果表明提出的多障碍物避碰算法具有可行性和实用性。该方法易于改进和扩展,且容易与当前主流的无人船控制系统结合,有利于无人船避碰系统快速工程化的实现。 相似文献
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In this paper, a hierarchical control framework with relevant algorithms is proposed to achieve autonomous navigation for an underactuated unmanned surface vehicle (USV) swarm. In order to implement automatic target tracking, obstacle avoidance and avoid collisions between group members, the control framework is divided into three layers based on task assignments: flocking strategy design, motion planning and control input design. The flocking strategy design transmits some basic orders to swarm members. Motion planning applies the potential function method and then improves it; thus, the issue of autonomous control is transformed into one of designing the velocity vector. In the last layer, the control inputs (surge force and yaw moment) are designed using the sliding mode method, and the problem of underactuation is handled synchronously. The proposed closed-loop controller is shown to be semi-asymptotically stable by applying Lyapunov stability theory, and the effectiveness of the proposed methodology is demonstrated via numeric simulations of a homogeneous USV swarm. 相似文献
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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
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Unmanned surface vehicles (USVs) are able to accomplish difficult and challenging tasks both in civilian and defence sectors without endangering human lives. Their ability to work round the clock makes them well-suited for matters that demand immediate attention. These issues include but not limited to mines countermeasures, measuring the extent of an oil spill and locating the source of a chemical discharge. A number of USV programmes have emerged in the last decade for a variety of aforementioned purposes. Springer USV is one such research project highlighted in this paper. The intention herein is to report results emanating from data acquired from experiments on the Springer vessel whilst testing its advanced navigation, guidance and control (NGC) subsystems. The algorithms developed for these systems are based on soft-computing methodologies. A novel form of data fusion navigation algorithm has been developed and integrated with a modified optimal controller. Experimental results are presented and analysed for various scenarios including single and multiple waypoints tracking and fixed and time-varying reference bearings. It is demonstrated that the proposed NGC system provides promising results despite the presence of modelling uncertainty and external disturbances. 相似文献
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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
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For autonomous manipulation in water, an underwater vehicle-manipulator system (UVMS) should be able to generate trajectori9es for the vehicle and manipulators and track the planned trajectories accurately. In this paper, for trajectory generation, we suggest a performance index for redundancy resolution. This index is designed to minimize the restoring moments of the UVMS during manipulation, and it is optimized without impeding the performance of a given task. As a result, the restoring moments of the UVMS are decreased, and control efforts are also reduced. For tracking control of the UVMS, a nonlinear H∞ optimal control with disturbance observer is proposed. This control is robust against parameter uncertainties, external disturbances, and actuator nonlinearities. Numerical simulations are presented to demonstrate the performance of the proposed coordinated motion control of the UVMS. The results show that control inputs for tracking are reduced, and the UVMS can successfully track generated trajectories. 相似文献
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We present a new type of model-free adaptive control (MFAC) method based on an adaptive forgetting factor for unmanned surface vehicle (USV) heading control under uncertain influence. Firstly, we analyze the compact form dynamic linearization based MFAC (CFDL-MFAC) method and its main problems with regard to USV heading control. Secondly, in order to address the problems of overshoot, oscillation, and slow convergence of the heading control with the MFAC method and considering the dynamics of the USV heading control subsystem, we introduce an adaptive forgetting factor into the CFDL-MFAC to arrive at the CFDL-MFAC with variable forgetting factor (CFDL-MFAC-VFF) method. Our simulation studies show that the CFDL-MFAC-VFF method yields low overshoot and low oscillations and is insensitive to changes in the system parameters and output error. Finally, our field experiments with the small USV “Dolphin-I” demonstrate the effectiveness and engineering practicability of our proposed method. 相似文献
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刘来华 《数字海洋与水下攻防》2019,2(5):14-19
针对无人驾驶载具在路径跟踪过程中容易受到环境外力干扰的问题，介绍了一种路径跟踪方法。对该方法进行了系统仿真和试验测试，与传统的线性PID控制算法进行了效果对比。结果显示:非线性算法具有较好的动态性能，并且可以减小环境干扰下的路径跟踪偏差，有效克服环境干扰作用。 相似文献
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The problem of the unmanned surface vessel(USV) path planning in static and dynamic obstacle environments is addressed in this paper. Multi-behavior fusion based potential field method is proposed, which contains three behaviors: goal-seeking, boundary-memory following and dynamic-obstacle avoidance. Then, different activation conditions are designed to determine the current behavior. Meanwhile, information on the positions, velocities and the equation of motion for obstacles are detected and calculated by sensor data. Besides, memory information is introduced into the boundary following behavior to enhance cognition capability for the obstacles, and avoid local minima problem caused by the potential field method. Finally, the results of theoretical analysis and simulation show that the collision-free path can be generated for USV within different obstacle environments, and further validated the performance and effectiveness of the presented strategy. 相似文献
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An effective path planning or route planning algorithm is essential for guiding unmanned surface vehicles (USVs) between way points or along a trajectory. The A* algorithm is one of the most efficient algorithms for calculating a safe route with the shortest distance cost. However, the route generated by the conventional A* algorithm is constrained by the resolution of the map and it may not be compatible with the non-holonomic constraint of the USV. In this paper an improved A* algorithm has been proposed and applied to the Springer USV. A new path smoothing process with three path smoothers has been developed to improve the performance of the generated route, reducing unnecessary ‘jags’, having no redundant waypoints and offering a more continuous route. Both simulation and experimental results show that the smoothed A* algorithm outperforms the conventional algorithm in both sparse and cluttered environments that have been uniformly rasterised. It has been demonstrated that the proposed improved A* route planning algorithm can be applied to the Springer USV providing promising results when tracking trajectories. 相似文献