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系泊船舶在不规则波中慢漂振荡的马尔可夫模型 总被引:1,自引:0,他引:1
一艘在非高斯慢漂波浪力激励下的系泊船舶的响应被用一个连续的马尔可夫过程来建模.提出了一个数值路径积分解法来计算该艘船舶的响应统计.该数值路径积分法是基于Gauss-Legendre插值方案,响应概率密度值是在子区间内的高斯分点上获得的.显示该数值路径积分解法有独特的能力在很低概率水平时生成精确解,这在系统可靠性分析时有重要意义. 相似文献
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针对动力定位船舶的循迹任务,提出了一种基于逆最优思想的自适应反步控制器,并对误差系统的稳定性进行了分析。首先对无干扰的动力定位船舶线性化模型设计最优跟踪控制器,利用时变Riccati方程进行反步状态变换得到误差系统,再基于 Lyapunov 函数对定常干扰设计自适应律和使系统渐近稳定的控制律,最后给出此控制律作用下的最优性能指标。该方法不用论证带有H∞范数的广义Riccati代数方程可解性,避免了传统非线性 H∞鲁棒控制需要求解 Hanmilton-Jacobi-Issacs(HJI)方程的问题。动力定位船舶的循迹控制仿真研究验证了算法的有效性。 相似文献
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Serret-Frenet框架下欠驱动船的输出反馈路径跟踪鲁棒控制 总被引:1,自引:1,他引:0
研究欠驱动船舶在规定速度条件下的路径跟踪控制问题,提出一种基于终端滑模与Backsteping方法相结合的复合输出反馈控制策略.该控制策略利用Backsteping能够获得控制算法显式解的优点,构造出控制器算法的结构形式,然后设计一个基于观测器设计的逆动态终端滑模面,使得系统的估计状态跟踪误差能够在有限时间到达滑模面上,最终达到系统可镇定.最后,通过Lyapunov稳定性理论证明该复合控制策略的稳定性.利用实船数据进行数字仿真,结果表明该控制策略具有良好的跟踪性能. 相似文献
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本文研究分析了基于领航者-跟随者的编队控制方法和基于路径跟随的编队控制方法等2种常用的AUV编队控制方法异同点。针对2种方法在路径点切换时航向变化较大的共性问题,提出采用B样条曲线对规划航路做在线的局部B样条拟合优化,对路径切换点处领航AUV的控制航向角作适度平滑处理。通过数值仿真验证了该方法可改善路径切换时,基于领航者-跟随者的编队控制中的跟随AUV目标跟踪位置变化速度和曲率,削弱了跟随AUV的点跟随难度;同时在路径跟随的编队控制中,利用B样条基函数自变量作为在切换点附近路径的同步控制参数的一部分,可提高切换点附近路径上编队的同步速度。 相似文献
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A path following control algorithm for an unmanned underwater vehicle(UUV) using temporary path generation guidance was proposed in this paper.Owing to different initial states of the vehicle,such as position and orientation,the path following control in the horizontal plane may yield a poor performance.To deal with the negative effect induced by initial states,a temporary path generation was presented based on the relationship between the original reference path and the vehicle’s initial states.With different relative positions between the vehicle and reference path,including out of straight lines,as well as inside and outside a circle,the related temporary paths guiding the vehicle to the reference path were able to be generated in real time.The vehicle was guided to steer along the temporary path until it reached the tangent point at the reference path,where the controller was designed using the input-output feedback linearization method.Simulation results demonstrated that the proposed algorithm is effective under the three different situations mentioned above. 相似文献
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A robust adaptive control strategy was developed to force an underactuated surface vessel to follow a reference path,despite the presence of uncertain parameters and unstructured uncertainties including exogenous disturbances and measurement noise.The reference path can be a curve or a straight line.The proposed controller was designed by using Lyapunov’s direct method and sliding mode control and backstepping techniques.Because the sway axis of the vessel was not directly actuated,two sliding surfaces were introduced,the first one in terms of the surge motion tracking errors and the second one for the yaw motion tracking errors.The adaptive control law guaranteed the uniform ultimate boundedness of the tracking errors.Numerical simulation results were provided to validate the effectiveness of the proposed controller for path following of underactuated surface vessels. 相似文献
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NTSM控制的AUV路径跟踪控制研究 总被引:3,自引:0,他引:3
针对非线性欠驱动自治水下机器人(Autonomous underwater vehicle,缩写为AUV),提出了一种基于非奇异终端滑模(Non—singular terminal sliding mode,缩写为NTSM)控制的鲁棒路径跟踪控制方法。在跟踪控制系统中,采用的参考变量为非时间量,摆脱了时间因素的影响,有利于提高AUV在不确定环境中的跟踪能力。应用指数趋近律进行NTSM控制器设计,能保证系统状态在有限时间内到达平衡点。数值仿真结果验证了该控制律的路径跟踪效能。 相似文献
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This paper mainly focuses on the heading control of a position-moored vessel operating under level ice regime. A dynamic ice simulator interconnecting the vessel motions with the ice dynamics is used for the design of the heading control system. The strategy is to ensure that the vessel is kept at an appropriate position within the safe limits. Using a heading controller based on a Kalman filter, the desired control force is computed to counteract the environmental disturbances. A thrust allocation method is developed to go with the heading controller. To keep the ice forces to a reasonable level, the moored vessel should be aligned with the ice drift direction and small angles up to 15° in changes on heading against the ice flow could be possible. Therefore, heading control of a moored vessel exposed to level ice with drift angle 0° and 15° is simulated since the dynamic positioning system needs to resist ice yaw moments and lateral ice forces on the hull. The simulation indicates that the proposed control strategy performs satisfactorily for a moored vessel in level ice. 相似文献
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针对仅使用槽道推进器提供横向推力的动力定位船舶路径跟踪控制问题,建立慢变环境干扰影响下的非线性船舶数学模型,设计带有自适应干扰补偿的反步控制算法来消除环境干扰的影响。引入平行目标接近(CB)导引算法为跟踪控制生成期望速度矢量信号,通过与所提出的自适应反步控制算法相结合,得到不受船舶驱动特性限制的全速度范围动力定位船舶导引跟踪控制算法,应用李雅普诺夫稳定性理论证明系统跟踪误差渐进收敛到零。仿真结果表明通过调整导引算法参数可以调节船舶跟踪过程表现,并可以得到较好的控制精度。 相似文献
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Station keeping control of remotely operated vehicles is crucial in the successful completion of underwater missions of work class robotic vehicles. The conventional method of station keeping using the vehicle pose/velocity measurement introduces delay in vehicle control and often leads to instability. In this paper, we present a novel method for measuring the underwater disturbances and controlling the robot for station keeping using a feed-forward control strategy. A strain-gauge based disturbance force measurement is proposed here with suitable algorithms to measure the forces acting on the vehicle due to external disturbances. Using the dynamic models, the vehicle response is predicted and a feed-forward control is implemented for station keeping. The controller activates corrective control action even before the vehicle responds to the disturbances. The performance of the controller is analyzed through simulation studies as well as hardware-in-loop tests. Results show that this approach is an effective alternative for conventional station keeping control of underwater vehicles. 相似文献
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本文针对无人船航向控制提出了基于模糊及遗传算法的控制策略。考虑无人船航向控制,以及无人船航向控制具有强非线性和不确定性,本文将智能策略和常规策略作为无人船航向的舵角控制作为主要控制框架。通过导引律计算期望的角度,并根据自主船的无人船航向控制动态模型进行分析。该模型考虑了舵和船舶推进系统的物理阈值,提出了一种适用于不同无人船航向控制的自适应控制算法,借助增益调度方法(GS),利用PID控制器和遗传算法(GA)对不同的操作点进行全流程的(GS-PID-GA)混合优化。通过真实数据比例缩小进行模型实验并与传统控制方法进行比较,验证了所提出的控制方法的有效性。 相似文献