共查询到19条相似文献，搜索用时 140 毫秒
1.
研究非完整移动机器人的轨迹跟踪控制问题。首先根据移动机器人侧向误差和角度误差的几何关系,提出了一种基于引导角的轨迹跟踪控制方法。然后利用Lyapunov直接法和积分Backstepping方法设计了基于引导角的轨迹跟踪控制器,并证明了移动机器人轨迹跟踪误差收敛性。最后通过仿真结果验证了本文方法的有效性。 相似文献
2.
水下拖曳系统在工作过程中拖体的俯仰角控制一直是水下拖体姿态控制的重要环节，设计了一种基于 RBF 神经网络的水下拖体直接自适应控制器，在闭环系统中利用 RBF 神经网络的局部无限逼近非线性函数的特性。将 RBF 神经网络的输出代替水下拖体动力学模型中的非线性不确定项，配合传统的 PD 控制器， 无需预先离线学习，在线学习更新神经网络权值，控制律和神经网络权值更新律经 Lyapunov 定理证明为稳定， 跟踪误差收敛到 0，通过计算机仿真比较该控制器与传统 PD 控制器的控制效果。 相似文献
3.
近年来,水下无人航行器(简称 UUV)在海洋资源勘测开发、海洋生态监测以及军事、经济、 社会等领域均有广泛应用,多 UUV 的编队控制成为国内外水下无人航行器研究的热点。首先给出了简化的三自由度 UUV 数学模型,然后通过平面直线的 Serret-Frenet 方程,建立 UUV 路径跟踪误差模型。通过运用领航者–跟随者方法构建 UUV 的编队控制模型,引入滑模控制的方法,对跟随者 UUV 的控制器进行设计,最终稳定地形成预设的编队。 相似文献
4.
水下机器人-机械臂系统的滑模自抗扰控制 总被引：1，自引：0，他引：1
针对水下机器人机械臂系统的强耦合、强非线性、复杂海洋多源干扰等因素影响，提出了滑模自抗扰控制器，将复杂系统模型转变为简单的积分串联系统，将内部参数不确定性、测量误差、建模误差和海洋多源干扰等扰动归结为总扰动，并采用线性扩张观测器对其进行估计并抵消。利用滑模控制器提高系统对参数摄动的不敏感性，增强控制系统的抗干扰性能，通过李雅普诺夫理论分析了控制系统的有界稳定性。仿真结果表明滑模自抗扰与传统滑模控制和自抗扰控制相比，能使水下机器人机械臂实现更好的轨迹跟踪，且系统具有更好的抗干扰能力。 相似文献
5.
针对水下无人航行器（UUV）受到海流海浪等外部扰动与内部模型不确定导致航向角控制品质下降的问题,提出一种基于自抗扰（ADRC）的双环路航向角控制方法。首先,建立了 UUV 的六自由度动力学、运动学模型与水平面动力学模型。然后,设计了一种非线性控制器,将自抗扰控制与双控制环路相结合, 针对系统航向控制所受内部与外部等非线性因素的影响,采用扩张状态观测器对“总和”扰动进行观测与补偿。 在采用自抗扰控制的航向角反馈控制回路的基础上,增加航向角速度内环,降低系统对扰动的灵敏度,改造被控对象的传递函数,为外环路提供良好的被控对象模型。最后,通过仿真实验验证了该控制方法的有效性。 相似文献
6.
GDROV是用于堤坝探测的水下机器人,设计上属于开架式机器人,其精确的数学模型很难获得.采用基于模糊逻辑的直接自适应控制方法,利用模糊基函数网络逼近理想控制输出,通过模糊逻辑动态调整控制器的参数自适应律,可有效解决水下机器人控制问题.建立GDROV的水动力模型,给出基于模糊逻辑的直接自适应控制算法,最后通过仿真试验和外场试验验证了该控制器对模型的不确定性具有较强的鲁棒性,且具有良好的跟踪性能. 相似文献
7.
合适的控制模型参数能够保证被控对象在较快的响应时间和较小的超调量下达到控制目标,无人水下航行器定深控制模型参数的优化设计对提升水下航行器使用性能具有重要意义。首先,建立了水下航行器空间运动学方程,基于 Modelica 建模语言构建了航行器虚拟样机及其定深控制模型。然后,以响应时间和超调量最小为优化目标,采用非支配排序差分进化算法建立了水下航行器定深控制模型参数多目标优化流程,基于 OPTIMUS 平台构建了水下航行器定深控制模型参数优化设计工作流。以某水下航行器为对象的实验结果表明：所提方法可快速获得较优的 PID 控制模型参数,优化后的水下航行器定深运动控制特性显著改善。 相似文献
8.
水下机器人避碰控制是自主作业的重要基础,但复杂的约束条件和模型的不精确性增加了避障路径跟踪的技术难度。在传统模型预测控制的基础上,结合作业场景多种约束条件,引入径向基函数神经网络,提出了一种水平面避碰控制方法。首先,采用径向基神经网络建立误差补偿函数,提高传统动力学预测模型精度;然后,结合避碰路径跟踪控制,在滚动优化环节选取性能指标函数,并显式引入障碍物、执行机构与控制稳定性等约束条件;最后,通过仿真试验证明该方法能够控制水下机器人跟踪避碰路径实现水平面内障碍物规避。 相似文献
9.
10.
研究自主水下航行器系统的软变结构控制策略问题。首先分析软变结构控制系统的结构特征,利用双曲正切函数,给出控制受限情形的软变结构控制策略。其次利用Lyapunov稳定性理论,讨论自主水下航行器软变结构控制系统的稳定性,然后构造了基于双曲正切函数的软变结构控制器,给出自主水下航行器软变结构控制的具体算法。基于双曲正切函数的自主水下航行器软变结构控制系统调节精度高,响应速度快,有效地削弱了系统抖振。最后通过一个仿真实验,比较了自主水下航行器垂直深度通道的4种控制策略对系统性能的影响,从而验证了研究方法的有效性。 相似文献
11.
This paper addresses the combined problem of trajectory planning and tracking control for underactuated autonomous underwater vehicles (AUVs) on the horizontal plane. Given a smooth, inertial, 2D reference trajectory, the planning algorithm uses vehicle dynamics to compute the reference orientation and body-fixed velocities. Using these, the error dynamics are obtained. These are stabilized using backstepping techniques, forcing the tracking error to an arbitrarily small neighborhood of zero. Simulation results for a constant velocity trajectory, i.e. a circle, and a time-varying velocity one, i.e. a sinusoidal path, are presented. The parametric robustness is considered and it is shown that tracking remains satisfactory. 相似文献
12.
State-dependent Riccati equation-based robust dive plane control of AUV with control constraints 总被引：1，自引：0，他引：1
The paper treats the question of suboptimal dive plane control of autonomous underwater vehicles (AUVs) using the state-dependent Riccati equation (SDRE) technique. The SDRE method provides an effective mean of designing nonlinear control systems for minimum as well as nonminimum phase AUV models. It is assumed that the hydrodynamic parameters of the nonlinear vehicle model are imprecisely known, and in order to obtain a practical design, a hard constraint on control fin deflection is imposed. The problem of depth control is treated as a robust nonlinear output (depth) regulation problem with constant disturbance and reference exogenous signals. As such an internal model of first-order fed by the tracking error is constructed. A quadratic performance index is chosen for optimization and the algebraic Riccati equation is solved to obtain a suboptimal control law for the model with unconstrained input. For the design of model with fin angle constraints, a slack variable is introduced to transform the constrained control input problem into an unconstrained problem, and a suboptimal control law is designed for the augmented system using a modified performance index. Using the center manifold theorem, it is shown that in the closed-loop system, the system trajectories are regulated to a manifold (called output zeroing manifold) on which the depth tracking error is zero and the equilibrium state is asymptotically stable. Simulation results are presented which show that effective depth control is accomplished in spite of the uncertainties in the system parameters and control fin deflection constraints. 相似文献
13.
14.
基于模糊神经网络理论对水下拖曳体进行深度轨迹控制 总被引：2，自引：0，他引：2
以华南理工大学开发的自主稳定可控制水下拖曳体为研究对象,首先通过水下拖曳体在拖曳水池样机中的试验取得试验数据后作为训练样本,采用LM BP算法,建立基于神经网络理论构建的可控制水下拖曳体轨迹与姿态水动力的数值模型。在此基础上设计了一个控制系统,它主要由两部分组成:基于遗传算法的神经网络辨识器和基于模拟退火改进的遗传算法的模糊神经网络控制器。以满足预先设定的拖曳体水下监测轨迹要求为控制依据,由控制系统确定为达到所要求的运动轨迹而应采用的迫沉水翼转角,以此作为输入参数,通过LM BP神经网络模型的模拟计算预报在这一操纵动作控制下的拖曳体所表现的轨迹与姿态特征。数值模拟计算结果表明:该系统的设计达到了所要求的目的;借助这一系统,可以有效地实现对拖曳体的深度轨迹控制。 相似文献
15.
以7 000 m载人潜水器的工程需求为背景,以水下单目摄像机为视觉传感器,进行了水下机器人动力定位方法研究。该动力定位方法利用视觉系统测量得到水下机器人与被观察目标之间的三维位姿关系,通过路径规划、位置控制和姿态控制分解,逐步使机器人由初始位姿逼近期望位姿并最终定位于期望位姿,从而实现了机器人的4自由度动力定位。通过水池实验验证了提出的动力定位方法,并且机器人能够抵抗恒定水流干扰和人工位置扰动。同时,该动力定位方法还可以实现机器人对被观察目标的自动跟踪。 相似文献
16.
Nonlinear path-following control of an AUV 总被引：3，自引：0，他引：3
A new type of control law is developed to steer an autonomous underwater vehicle (AUV) along a desired path. The methodology adopted for path-following deals explicitly with vehicle dynamics. Furthermore, it overcomes stringent initial condition constraints that are present in a number of path-following control strategies described in the literature. Controller design builds on Lyapunov theory and backstepping techniques. The resulting nonlinear feedback control law yields convergence of the path-following error trajectory to zero. Simulation results illustrate the performance of the control system proposed. 相似文献
17.
A new control scheme for robust trajectory control based on direct estimation of system dynamics is proposed for underwater vehicles. The proposed controller can work satisfactorily under heavy uncertainty that is commonly encountered in the case of underwater vehicle control. The dynamics of the plant are approximately canceled through the feedback of delayed accelerations and control inputs. Knowledge of the bounds on uncertain terms is not required. It is shown that only the rigid body inertia matrix is sufficient to design the controller. The control law is conceptually simple and computationally easy to implement. The effectiveness of the controller is demonstrated through simulations and implementation issues are discussed. 相似文献
18.
This paper addresses the problem of simultaneous depth tracking and attitude control of an underwater towed vehicle. The system proposed uses a two-stage towing arrangement that includes a long primary cable, a gravitic depressor, and a secondary cable. The towfish motion induced by wave driven disturbances in both the vertical and horizontal planes is described using an empirical model of the depressor motion and a spring-damper model of the secondary cable. A nonlinear, Lyapunov-based, adaptive output feedback control law is designed and shown to regulate pitch, yaw, and depth tracking errors to zero. The controller is designed to operate in the presence of plant parameter uncertainty. When subjected to bounded external disturbances, the tracking errors converge to a neighbourhood of the origin that can be made arbitrarily small. In the implementation proposed, a nonlinear observer is used to estimate the linear velocities used by the controller thus dispensing with the need for costly sensor suites. The results obtained with computer simulations show that the controlled system exhibits good performance about different operating conditions when subjected to sea-wave driven disturbances and in the presence of sensor noise. The system holds promise for application in oceanographic missions that require depth tracking or bottom-following combined with precise vehicle attitude control. 相似文献
19.
Antonelli G. Caccavale F. Chiaverini S. Villani L. 《Oceanic Engineering, IEEE Journal of》2000,25(3):399-413
In this paper, the problem of tracking a desired motion trajectory for an underwater vehicle-manipulator system without using direct velocity feedback is addressed. For this purpose, an observer is adopted to provide estimation of the system's velocity needed by a tracking control law. The combined controller-observer scheme is designed so as to achieve exponential convergence to zero of both motion tracking and estimation errors. In order to avoid representation singularities of the orientation, unit quaternions are used to express the vehicle attitude. Implementation issues are also considered and simplified control laws are suggested, aimed at suitably trading off tracking performance against reduced computational load. Simulation case studies are carried out to show the effectiveness of the proposed controller-observer algorithm. The obtained performance is compared to that achieved with a control scheme in which the velocity is reconstructed via numerical differentiation of position measurements. The results confirm that the chattering on the control commands is significantly reduced when the controller-observer strategy is adopted in lieu of raw numerical differentiation; this leads to lower energy consumption at the actuators and increases their lifetime 相似文献