To improve the performance of autonomous underwater vehicle in trajectory tracking control, which is subject to system uncertainties and time-varying external disturbances, a nonlinear disturbance observer-based sliding mode controller proposed study. First, reaching law with special power function hyperbolic tangent presented. Then an improved based on new combined decrease time avoid chattering during control. Furthermore, reduce influence observer introduced identify them. The error...

Target following plays an important role in oceanic detection and target capturing for autonomous underwater vehicles. Due to the model nonlinearity external disturbance, dynamic of a portable vehicle was usually established with parameter uncertainties. In this article, petri-based recurrent type 2 fuzzy neural network has been built approximate unknown dynamics. The logic system applied improve approximation accuracy systematic nonlinearity, petri layer can estimation speed reduce energy...

Open-frame is one of the major types structures Remote Operated Vehicles (ROV) because it easy to place sensors and operations equipment onboard. Firstly, this paper designed a petri-based recurrent neural network (PRFNN) improve robustness with response nonlinear characteristics strong disturbance an open-frame underwater vehicle. A threshold has been set in third layer reduce amount calculations regulate training process. The whole convergence guaranteed selection learning rate parameters....

Underwater vehicles are being emphasized as highly integrated and intelligent devices for a significant number of oceanic operations. However, their precise operation is usually hindered by disturbances from tether or manipulator because propellers unable to realize stable suspension. A dynamic multi-body model-based adaptive controller was designed allow the vehicle observe compensate manipulator. Disturbances, including those manipulator, deduced observation controller. An analysis...

This study addresses the question of 3D path following for observation class underwater remotely operated vehicle. The dynamic model investigated remote vehicle is taken as a coupled multibody system composing flexible body and rigid body. For precise control, tether cable disturbance has been well via model. Each element tethered even an elastic body, waves current disturbances have into consideration. Based on model, adaptive backstepping sliding mode controller designed. To improve...

The forward and inverse dynamic models of the underactuated 2-DOF finger have been established in this article based on virtual spring approach. This approach not only avoids solution differential-algebraic equations but also leads to a completely decoupled model that is ideal for directly analysis, real-time simulation control. To verify approach, an 3-joint has brought forward. Simulation results from Matlab/Simulink are consistent with those obtained ADAMS grasp simulations. For hand...

Precise motion control of remotely operated vehicles plays an important role in a great number submarine missions. However, the high-performance operations are difficult to realize due uncertainty system modeling with self-disturbance. On basis multibody dynamics, self-disturbances from tether and manipulator have been systematically analyzed order transform them into observed forces. A novel S surface–based adaptive recurrent wavelet neural network has proposed on nonlinear underwater...

In underwater vehicles controlled by thrusters and fins, effect of the AUV depth control could be seriously affected because dead zone nonlinearity in steering gear transmission system. This paper takes a certain as an example. this paper, nonlinear pid controller is desired considering actuator being saturated; response speed improved through tracking differentiator; dynamic performance using combination. Also, PID with adaptive compensation given. The programmed consider system;...

Zero-valent iron (ZVI) has been extensively studied for its efficacy in removing heavy metals, nitrate, and chlorinated organic compounds from contaminated water. However, limited effectiveness due to rapid passivation poor selectivity is prompting alternative solutions, such as the use of aluminium alloys. In this study, five distinct alloys, namely Al–Mg, Al–Fe, Al–Cu, Al–Ni, each comprising 50 % Al by mass at a concentration 10 g/L, was assessed using copper, nitrate trichloromethane...

The purpose of this paper was to construct a velocity observer based on the dynamic model and realize accurate curve force control. Curve fitting with obtained precise signals. Compared PID factored moment methods, it decreased errors lot achieved ideal results. Compensated inverse equation, force-based impedance control could not only tracking, but achieve finger by combination tracking. Furthermore, static grasp established for appropriate distribution. slippery, fragile, comparatively...

Underwater autonomous manipulation is a challenging task which not only includes complicated multibody dynamic and hydro-dynamic process, but also involves the limited observation environment. This paper proposed to investigate current state of art about underwater technology. Although lot research aiming at under-water vehicle manipulator system (UVMS) large-scale AUV have been carried out by scientists in Italy, Spain etc. However, there has long lack studies on portable AUV. So this...

In consider of docking task AUV and underwater moving platform, an tracking controller is designed. this controller, target trajectory calculated to determine expected velocity heading angle, during which, Lyapunov stability law followed. An angle designed based on active disturbance rejection (ADRC) considered the perturbation system model establishment external disturb. The performed well, as proved in simulation experiment, that tracked effectively by controller.

In order to improve the Remote Operated Vehicle (ROV) into a reliable and maintainable one, this paper has presented fault tolerance control system structure. Its surface platform includes diagnosis modules. module, second sliding mode observer been built on basis of its dynamic model, so as diagnose thrusters’ conditions through residue command quantity. Coresponding with position, force allocation model established realize tolerable control. Based duality priciple, energy-like function...

Zerovalent iron (ZVI) has been extensively studied for removing heavy metals, nitrate, and chlorinated organic compounds from contaminated water, but its effectiveness is limited by rapid passivation poor selectivity. In this study, we investigated the potential of aluminum alloys, specifically Al-Mg, Al-Fe, Al-Cu, Al-Ni (with 50% Al mass), copper, trichloromethane (TCM) water. Our results showed that pollutants reacted immediately with while an induction period 24 hours was observed due to...

In this paper, considering the influence of mixed traffic and overtaking on flow, formula viscous resistance was put forth; a new Hydrodynamics model established. Discrete analysis carried out mechanical equation through difference method, which change in flows parameters time space can be analyzed. Finally, measured data simulation results show that flow is certain practical reference.