共查询到20条相似文献，搜索用时 599 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.
Unmanned underwater vehicles (UUVs) typically operate in uncertain and changing environments. Globally convergent Lyapunov-based parameter-adaptive controllers for six-degree-of-freedom position and attitude trajectory-tracking control of astable UUVs have been successfully derived and applied. We propose an efficient adaptive-control scheme for UUVs based on existing parameter-adaptation schemes popular in the robotics literature. Specifically, we customize bounded-gain-forgetting composite adaptation, which utilizes information about both the tracking and model-prediction errors to yield faster parameter convergence than the traditional tracking-error-based (TEB) adaptation. Hence, better transient behavior of tracking errors is achieved by using fewer control efforts in most cases. We show the effectiveness of applying the suggested adaptation scheme on UUVs through simulation. 相似文献
3.
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
4.
In this paper, the control of autonomous underwater vehicles (AUVs) in six-degrees-of-freedom (6-DOFs) is analyzed in a comparison study among several controllers. At steady state, the vehicle needs to compensate for two dynamic effects, the ocean current and the restoring forces; the appropriateness of the adaptive/integral action designed with respect to the persistent effects is discussed. Moreover, for each controller, an adaptive/integral proportional derivative (PD) plus gravity compensation-like version is derived and eventually modified so as to achieve null steady-state error under modeling uncertainty and presence of ocean current. Numerical simulations are presented to better illustrate the controllers' behavior. 相似文献
5.
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
6.
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
7.
Mechanics and control of swimming: a review 总被引：2，自引：0，他引：2
The bodies and brains of fish have evolved to achieve control objectives beyond the capabilities of current underwater vehicles. One route toward designing underwater vehicles with similar capabilities is to better understand fish physiological design and control strategies. This paper has two objectives: 1) to review clues to artificial swimmer design taken from fish physiology and 2) to formalize and review the control problems that must be solved by a robot fish. The goal is to exploit fish locomotion principles to address the truly difficult control challenges of station keeping under large perturbations, rapid maneuvering, power-efficient endurance swimming, and trajectory planning and tracking. The design and control of biomimetic swimming machines meeting these challenges will require state-of-the-art engineering and biology. 相似文献
8.
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
9.
Multi-AUV Control and Adaptive Sampling in Monterey Bay 总被引：3，自引：0，他引：3
Edward Fiorelli Naomi Ehrich Leonard Pradeep Bhatta Derek A. Paley Ralf Bachmayer David M. Fratantoni 《Oceanic Engineering, IEEE Journal of》2006,31(4):935-948
Operations with multiple autonomous underwater vehicles (AUVs) have a variety of underwater applications. For example, a coordinated group of vehicles with environmental sensors can perform adaptive ocean sampling at the appropriate spatial and temporal scales. We describe a methodology for cooperative control of multiple vehicles based on virtual bodies and artificial potentials (VBAP). This methodology allows for adaptable formation control and can be used for missions such as gradient climbing and feature tracking in an uncertain environment. We discuss our implementation on a fleet of autonomous underwater gliders and present results from sea trials in Monterey Bay in August, 2003. These at-sea demonstrations were performed as part of the Autonomous Ocean Sampling Network (AOSN) II project 相似文献
10.
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
11.
This paper reports comparative experiments with two novel and one conventional thrust control algorithms for the unsteady (transient) control of thrust generated by conventional bladed-propeller marine thrusters. First, comparative experiments with three different thrust control algorithms over a wide range of unsteady operating conditions suggest that model-based control algorithms offer transient thrust-control performance superior to that of their nonmodel-based counterpart. Second, hybrid simulations combining actual real-time experimental thruster responses with simulated one-dimensional real-time vehicle dynamics suggest that model-based thrust control algorithms offer vehicle position control superior to that of its nonmodel-based counterpart 相似文献
12.
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
13.
This paper presents an improved active disturbances rejecter control (ADRC) for path following control of autonomous underwater vehicles under significant fast-varying disturbances caused by waves and sea currents. Two significant and efficient improvements are introduced to the traditional ADRC in order to accomplish this task. First, a generalized ESO (GESO) and Harmonic ESO (HESO) were designed to achieve a high disturbances estimation quality. Secondly, two AUV path following controllers based on ADRC-GESO and ADRC-HESO were designed to ensure a high performance tracking in presence of periodic-type disturbances. Finally, numerical simulations were performed and the obtained results showed very significant enhancements of robustness and tracking accuracy by the proposed methods compared to conventional ADRC. 相似文献
14.
An adaptive control scheme for dynamic positioning (DP) of remotely operated underwater vehicles (ROV) is proposed based on a recently developed output feedback variable structure control (VSC) algorithm named VS-MRAC. Only position measurement is required. Precise modeling of the ROV is not needed and unmodeled perturbations can be effectively rejected. A simple method for discretizing the original continuous-time VS-MRAC is proposed based on dead-beat response. Other important practical implementation issues are considered. The performance is evaluated by simulation with a realistic ROV model and by full-scale experimental pool tests with an actual ROV 相似文献
15.
In this study, a dynamic modeling method for foil-like underwater vehicles is introduced and experimentally verified in different sea tests of the Hadal ARV. The dumping force of a foil-like underwater vehicle is sensitive to swing motion. Some foil-like underwater vehicles swing periodically when performing a free-fall dive task in experiments. Models using conventional modeling methods yield solutions with asymptotic stability, which cannot simulate the self-sustained swing motion. By improving the ridge regression optimization algorithm, a grey-box modeling method based on 378 viscous drag coefficients using the Taylor series expansion is proposed in this study. The method is optimized for over-fitting and convergence problems caused by large parameter matrices. Instead of the PMM test data, the unsteady computational fluid dynamics calculation results are used in modeling. The obtained model can better simulate the swing motion of the underwater vehicle. Simulation and experimental results show a good consistency in free-fall tests during sea trials, as well as a prediction of the dive speed in the swing state. 相似文献
16.
17.
Unmanned Underwater Vehicles (UUVs) are increasingly being used in advanced applications that require them to operate in tandem with human divers and around underwater infrastructure and other vehicles. These applications require precise control of the UUVs which is challenging due to the non-linear and time varying nature of the hydrodynamic forces, presence of external disturbances, uncertainties and unexpected changes that can occur within the UUV’s operating environment. Adaptive control has been identified as a promising solution to achieve desired control within such dynamic environments. Nevertheless, adaptive control in its basic form, such as Model Reference Adaptive Control (MRAC) has a trade-off between the adaptation rate and transient performance. Even though, higher adaptation rates produce better performance they can lead to instabilities and actuator fatigue due to high frequency oscillations in the control signal. Command Governor Adaptive Control (CGAC) is a possible solution to achieve better transient performance at low adaptation rates. In this study CGAC has been experimentally validated for depth control of a UUV, which is a unique challenge due to the unavailability of full state measurement and a greater thrust requirement. These in turn leads to additional noise from state estimation, time-delays from input noise filters, higher energy expenditure and susceptibility to saturation. Experimental results show that CGAC is more robust against noise and time-delays and has lower energy expenditure and thruster saturation. In addition, CGAC offers better tracking, disturbance rejection and tolerance to partial thruster failure compared to the MRAC. 相似文献
18.
A position and attitude tracking control law for autonomous underwater vehicles (AUV's) in 6 degrees of freedom (DOF) is derived. The 4-parameter unit quaternion (Euler parameters) is used in a singularity-free representation of attitude. Global convergence of the closed-loop system is proven. In addition, several 3-parameter representations in terms of the Euler parameters are discussed with application to the same control law. These schemes contain singularities, and only local convergence can therefore be proven. The proposed control scheme is simulated with Euler parameters and Euler angles 相似文献
19.
水声通信和测距能力是实现水下航行器准确定位的重要技术手段。当前基于水声定位的方法主要有利用测距和测向功能的水声定位技术以及水声测距辅助导航技术，二者的系统物理复杂度都比较高。本文提出了一种基于单水声信标距离量测的匹配定位方法，航行器在水声信标测距覆盖范围内，利用航行过程中多次测距信息构建测距圆序列形成位置约束，基于航位推算导航信息，将航行器在连续测距时间段内的相对航迹在圆序列上进行最优匹配，从而获得位置估计，通过对测距误差进行补偿可进一步提升定位精度。本方法所需物理系统结构复杂度低、可操作性强，仿真实验表明，该方法可以独立实现较高精度的定位。 相似文献
20.
This work develops a control system for the waypoint-tracking of a biomimetic autonomous underwater vehicle (BAUV). The BAUV swims forward by oscillating its body and caudal fin. It turns by bending its body and caudal fin toward the turning direction. The control algorithm uses the oscillating frequency to control the forward velocity, and applies a body-spline offset parameter to control the heading velocity. The motion of the BAUV is undulatory, so moving averages of swimming velocity and heading errors are used as feedback signals. The stability of the control system is discussed using a Lyapunov function. Finally, the effectiveness of the control algorithm is experimentally confirmed. 相似文献