共查询到20条相似文献，搜索用时 93 毫秒
1.
《Ocean Engineering》2006,33(11-12):1413-1430
This paper presents the design of an adaptive input–output feedback linearizing dorsal fin control system for the yaw plane control of low-speed bio-robotic autonomous underwater vehicles (BAUVs). The control forces are generated by cambering two dorsal fins mounted in the vertical plane on either side of the vehicle. The BAUV model includes nonlinear hydrodynamics, and it is assumed that its hydrodynamic coefficients as well as the physical parameters are not known. For the purpose of design, a linear combination of the yaw angle tracking error and its derivative and integral is chosen as the controlled output variable. An adaptive input–output feedback linearizing control law is derived for the trajectory control of the yaw angle. Unlike indirect adaptive control, here the controller gains are directly tuned. The stability of the zero dynamics is examined. Simulation results are presented for tracking exponential and sinusoidal yaw angle trajectories and for turning maneuvers, and it is shown that the adaptive control system accomplishes precise yaw angle control of the BAUV using dorsal fins in spite of the nonlinearity and large uncertainties in the system parameters. 相似文献
2.
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
3.
Robust optimal output tracking control of a midwater trawl system based on T-S fuzzy nonlinear model
A robust optimal output tracking control method for a midwater trawl system is investigated based on T-S fuzzy nonlinear model.A simplified nonlinear mathematical model is first employed to represent a midwater trawl system,and then a T-S fuzzy model is adopted to approximate the nonlinear system.Since the strong nonlinearities and the external disturbance of the trawling system,a mixed H 2 /H ∞ fuzzy output tracking control strategy via T-S fuzzy system is proposed to regulate the trawl depth to follow a desired trajectory.The trawl depth can be regulated by adjusting the winch velocity automatically and the tracking error can be minimized according to the robust optimal criterion.In order to validate the proposed control method,a computer simulation is conducted.The simulation results indicate that the proposed fuzzy robust optimal controller make the trawl net rapidly follow the desired trajectory under the model uncertainties and the external disturbance caused by wave and current. 相似文献
4.
基于分布式控制力矩陀螺的水下航行器轨迹跟踪控制 总被引：2，自引：0，他引：2
基于控制力矩陀螺群(CMGs)的水下航行器具有低速或零速机动的能力。采用基于分布式CMGs的水下航行器方案,并研究其水平面的轨迹跟踪控制问题。通过全局微分同胚变换将非完全对称的动力学模型解耦成标准欠驱动控制模型,并根据简化的模型构建其轨迹跟踪的误差动力学模型,将轨迹跟踪控制问题转化为误差模型镇定问题。基于一种分流神经元模型和反步法设计了系统的轨迹跟踪控制律,该控制器不需要对任何虚拟控制输入进行求导计算,且能确保跟踪误差的最终一致有界性。仿真结果表明该控制器能够实现在不依赖动力学参数先验知识的情况下对光滑轨迹的有效跟踪。 相似文献
5.
研究在持续外界扰动作用下,具有控制时滞线性系统的动态输出反馈扰动抑制问题。首先利用模型转换将控制时滞系统转化为形式上无时滞的系统,通过求解Riccati方程和Sylvester方程,推导出前馈—反馈最优扰动抑制控制律。然后构造能同时预估状态和扰动的降维观测器,不仅解决前馈控制和状态反馈的物理不可实现问题,而且得到了近似于最优扰动抑制控制律的动态输出反馈扰动抑制控制器。仿真实例证明此控制律的有效性。 相似文献
6.
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
7.
一类非线性系统次优控制的灵敏度法 总被引：1，自引：0，他引：1
本文研究一类非线性定常系统的次优控制问题。通过在系统中引入 1个灵敏度参数并将系统变量关于灵敏度参数展开 Maclaurin级数 ,使求解最优控制的非线性两点边值问题化为一族线性两点边值问题。利用截取最优控制级数的有限项求得系统的次优控制律。仿真实例表明 ,该方法对非线性系统次优控制律的设计是有效的 相似文献
8.
Pradeep R. Nambisan 《Ocean Engineering》2009,36(2):158-167
A multi-variable adaptive autopilot for the dive-plane control of submarines is designed. The vehicle is equipped with bow and stern hydroplanes for maneuvering. It is assumed that the system parameters are not known, and the disturbance force is acting on the vehicle. Based on a back-stepping design approach, an adaptive control law is derived for the trajectory control of the depth and the pitch angle. To prevent singularity in the control law, the SDU decomposition of the high-frequency gain matrix is used for the design. In the closed-loop system, asymptotic tracking of the reference depth and pitch angle trajectories is accomplished. Simulation results are presented which show that the submarine performs dive-plane maneuvers in spite of the uncertainties in the system parameters and disturbance forces. 相似文献
9.
This paper is concerned with the formation control problem of multiple underactuated surface vessels moving in a leader-follower formation.The formation is achieved by the follower to track a virtual target defined relative to the leader.A robust adaptive target tracking law is proposed by using neural network and backstepping techniques.The advantage of the proposed control scheme is that the uncertain nonlinear dynamics caused by Coriolis/centripetal forces,nonlinear damping,unmodeled hydrodynamics and disturbances from the environment can be compensated by on line learning.Based on Lyapunov analysis,the proposed controller guarantees the tracking errors converge to a small neighborhood of the origin.Simulation results demonstrate the effectiveness of the control strategy. 相似文献
10.
具有小时滞的线性系统次优控制的无滞后转换法 总被引：1，自引：0，他引：1
该文研究线性时滞定常系统的次优控制问题。根据无滞后转换法的思想 ,先引入状态向量的增量 ,将其视为附加扰动输入 ,再利用微分方程的逐次逼近法 ,将既含有时滞项又含有超前项的两点边值问题化为既不含时滞项又不含超前项的两点边值问题族。然后 ,把第 N次逼近得到的控制律近似为系统的最优控制律 ,得到次优控制律。并用实例仿真验证了该算法的有效性。该方法可使小时滞系统的迭代次数大大减少 ,因此尤其适合于小时滞系统的次优控制。 相似文献
11.
An semi-analytical solution is derived for the optimal control of the power take-off of a single-degree of freedom heave point absorber with constraints on the displacement. At first the control force is derived during states, where the displacement constraint is active. This results in an open-loop control law dependent on the external wave load on the absorber. Next, the analytical solution for the optimal control in the unconstrained state is indicated, which turns out to be of the closed loop type with feedback from the present displacement and acceleration and from future velocities. The derived control law contains an undetermined constant, which is calibrated at the interface to the previous constrained state. The approach requires the estimation of the wave load during the constrained states, and the prediction of the future velocity response during unconstrained states. An algorithm has been devised in the paper for handling these problems. The theory has been validated against numerical solutions obtained by nonlinear programming. 相似文献
12.
Biologically inspired maneuvering of autonomous undersea vehicles (AUVs) in the dive plane using pectoral-like oscillating fins is considered. Computational fluid dynamics are used to parameterize the forces generated by a mechanical flapping foil, which attempts to mimic the pectoral fin of a fish. Since the oscillating fins produce periodic force and moment of a variety of wave shapes, the essential characteristics of these signals are captured in their Fourier expansions. Maneuvering of the biorobotic AUV in the dive plane is accomplished by periodically altering the bias angle of the oscillating fin. Based on a discrete-time AUV model, an inverse control system for the dive-plane control is derived. It is shown that, in the closed-loop system, the inverse control system accomplishes accurate tracking of the prescribed time-varying depth trajectories and the segments of the intersample depth trajectory remain close to the discrete-time reference trajectory. The results show that the fins located away from the center of mass toward the nose of the vehicle provide better maneuverability. 相似文献
13.
研究Lorenz混沌系统的同步控制问题,提出1种在多输入的情况下实现混沌同步的变结构控制算法.利用该算法设计的变结构同步控制律使得同步误差系统的运动在切换面上成为渐近稳定的滑动模态,从而较快的实现了混沌同步.通过对 Lorenz 混沌系统的理论分析和数值仿真,说明了该变结构同步控制策略的实用性和有效性. 相似文献
14.
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
15.
Path following of underactuated marine surface vessels using line-of-sight based model predictive control 总被引：1，自引：0，他引：1
This paper presents a model predictive control (MPC) for a way-point tracking of underactuated surface vessels with input constraints. A three-degree-of-freedom dynamic model of surface vessels has been used for the controller design. In order for the control action to render good helmsman behavior, a MPC scheme with line-of-sight (LOS) path generation capability is formulated. Quadratic programming (QP) is used to solve a linear MPC by successive linearization along the LOS model of the surface vessel. Furthermore, we show that an LOS decision variable can be incorporated into the MPC design to improve the path following performance. The effectiveness of the developed control law is demonstrated via computer simulations. 相似文献
16.
A global trajectory tracking controller is presented for underactuated AUVs with only surge force and yaw moment in the horizontal plane. A transformation is introduced to represent the tracking error system into a cascade form. The global and uniform asymptotic stabilization problem of the resulting cascade system is reduced to the stabilization problem of two subsystems by use of the cascade approach. For the stabilization of the subsystem involving the yaw moment, a control law is proposed based on the feedback linearization method. Another subsystem is stabilized by designing a fuzzy sliding mode controller which can offer a systematical means of constructing a set of shrinking-span and dilating-span membership functions. In order to demonstrate the practicability of the proposed controller, control constraints, parameter uncertainties, and external disturbances are considered according to practical situation of AUVs. Simulation results show very good tracking performance and robustness of the proposed control schemes. 相似文献
17.
An adaptive output feedback controller based on neural network feedback-feedforward compensator (NNFFC) which drives a surface ship at high speed to track a desired trajectory is designed. The tracking problem of the surface ship at low speed has been widely investigated. However, the coupling interactions among the forces from each degree of freedom (DOF) have not been considered in general. Furthermore, the influence of the hydrodynamic damping is also simplified into a linear form or neglected. On the contrary, coupling interactions and the nonlinear characteristics of the hydrodynamic damping can never be neglected in high speed maneuvering situation. For these reasons, the influence of the nonlinear hydrodynamic damping on the tracking precision is considered in this paper. Since the hydrodynamic coefficients of the surface ship at high speed are very difficult to be accurately estimated as a prior, it will be compensated by NNFFC as an unknown part of the tracking dynamics system. The stability analysis will be given by the Lyapunov theory. It indicates that the proposed control scheme can guarantee that all the signals in the closed-loop system are uniformly ultimately bounded (UUB), and numerical simulations can illustrate the excellent tracking performance of the surface ship at high speed under the proposed control scheme. 相似文献
18.
研究具有二次型性能指标的离散时滞双线性系统最优控制问题。对既带有时间超前项又带有时间滞后项的非线性两点边值(TPBV)问题,通过逐次逼近算法(SAA)构造不含超前滞后项的线性非齐次TPBV问题迭代序列。最优控制律由精确的线性反馈项和非线性时滞补偿序列的极限项组成。取补偿项序列的有限次迭代值,获得次优控制律。通过仿真,验证算法的有效性。 相似文献
19.
Depth-trim mapping control of underwater vehicle with fins 总被引：1，自引：1，他引：0
Underwater vehicle plays an important role in ocean engineering.Depth control by fin is one of the difficulties for underwater vehicle in motion control.Depth control is indirect due to the freedom coupling between trim and axial motion.It includes the method of dynamic analysis and lift-resistance-coefficient experiment and theory algorithm.By considering the current speed and depth deviation,comprehensive interpretation is used in object-planning instruction.Expected depth is transformed into expected trim.Dynamic output fluctuation can be avoided,which is caused by linear mapping of deviation.It is steady and accurate for the motion of controlled underwater vehicles.The feasibility and efficiency of the control method are testified in the pool and natural area for experiments. 相似文献
20.
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