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Design of a laboratory scale wave energy converter (WEC) system based on planar double-sided permanent magnet linear generator (PMLG) is considered in this paper. The detail procedure in designing the PMLG is reported including analytical work and experimental testing. The main objective is to create a simple and easy procedure in the design and optimize the detailed parameters to achieve the aimed...
Through and comprehensive tests are necessary to ensure complete stability and reliability of AUV, due to the high risk and consumption of in field testing, onshore testing technology for AUV is proposed. Rudder load simulator plays an important role in the onshore testing of AUV. In this paper, the design and development of a rudder load simulator was discussed. Rudder load calculation method during...
Based on the current widespread use of underwater vehicles, a special type of underwater glider equipped with energy-saving diamond-structured rotatable wings that can improve the underwater vehicle's lift-drag ratio optimize hydrodynamic performance, and enhance flight quality was studied. With the support of adaptive meshing technology and Fluent's epsilon standard turbulence model, lift and drag...
The expanding use of armed, unmanned systems is not only changing the face of modern warfare, but is also altering the process of decision-making in combat operations. These systems have been used extensively in the conflicts in Iraq and Afghanistan, and will continue to be equally relevant — if not more so — as the United States' strategic focus shifts towards the Asia-Pacific region and the high-end...
The capability of avoiding static obstacles independently is the premise for air cushion vehicle (ACV) operating safely. In this article, an ACV collision avoidance control based on improved artificial potential field method is designed as auxiliary operating system to ensure safe navigation of ACV. It builds mathematical model of the ACV and searches the data of static obstacles. Besides, the collision...
During the launching of the AUV especially in air-launching, the water entry problem is inevitable. The AUV will stir the flow field of surrounding fluid during the moving into water, while the fluid will act a strong force on the AUV in return, which may cause trajectory deflection problems or damage to their structure and inner components in severe cases. The water entry experiment of full-size...
This article presents a new water strider-like robot with buoyancy as the supporting force that is inspired by the water strider which can stand, glide and leap on the surface of water. The stroke mechanism of the robot has little disturbance to the water and is favorable for the stability of the water strider-like robot without extra action when it enters and leaves the water surface. Based on Interaction...
In this study, the hydrodynamic performance of a dish-shaped autonomous underwater helicopter (AUH) in waves near the sea surface is examined. The AUH is a novel type of autonomous underwater vehicle (AUV) that has excellent maneuverability and flexibility. The hydrodynamic performance of a dish-shaped autonomous underwater helicopter (AUH) in waves near the sea surface is estimated. An AUH is a novel...
A vectored thruster based on 3-RRRR parallel manipulator for small-size AUVs is designed to solve some drawbacks of conventional AUVs, which the control surfaces become ineffective at zero or slow forward speeds. Though this method, the thrust from duck propeller is controlled by the parallel manipulator. This approach has advantages of high stiffness, high mobile and large payload capacity. The parallel...
In this paper, we employ a dynamics modeling method for investigating a multi-body dynamics system consisting of an unmanned surface vehicle (USV), an umbilical cable (UC), and an autonomous underwater vehicle (ROV). The ROV, which is towed by a UC for the purposes of exploration or mine hunting, is modeled with a Six-Degree-of-Freedom (6-DOF) equation of motion that reflects its hydrodynamics characteristics...
In this study, virtual planar-motion-mechanism (PMM) tests in pure sway motion at constant forward speed are carried out to determine the sway added mass values of a 6:1 prolate spheroid. Added mass values are obtained by solving the Euler equations and the Reynolds Averaged Navier-Stokes (RANS) equations across a range of frequencies and depths. The effect that distance from the surface and radiation...
In this paper, the conceptual design with integrating motion control and considering the cross current was applied to establish a submarine motion simulator, where the path motion stability is evaluated. The methods used to construct the simulator include the standard navigation approach by applying the LOS algorithms and PD control Euler-Rodriguez quaternion for conversion between submarines motion...
Recently, coastal city and facilities had many damages by abnormally high waves with climate change. Especially, breakwater systems based on a caisson-type harm damages in Korea because they are located in the outside port. In order to reduce theses damages, new type breakwater systems using interlocking caisson are researched. Generally, caissons of breakwater system were constructed on crushed rock...
The development and the test of a palm size finless torpedo shaped micro autonomous underwater vehicle (AUV) named Lancelet are presented. The vehicle has a diameter of 60 mm and only weighs 570 g. It has no appendages such as rudders, elevators, external propellers or other unprotected moving surfaces, which might increase the drag of the vehicle and interfere with the underwater obstacles. A novel...
In order to solve the curved-path path following problem for underactuated autonomous underwater vehicle (AUV) in the presence of ocean currents, this paper proposes a modified Line-of-Sight (LOS) path following control strategy. The guidance law is derived based on a new path-following error kinematic model with relative velocities of the vehicle in the Serret-Frenet frame, which makes the AUV produce...
In order to improve the maneuverability and safety of the air cushion vehicle (ACV), considering the internal uncertainties, external disturbances, chattering in sliding mode control, the second order nonsingular terminal sliding mode (SONTSM) controller with extended state observer (ESO) is designed to achieve the course control of ACV. The course controller includes two parts: second order nonsingular...
This paper presents the motion simulation of an autonomous underwater helicopter (AUH), a new type of underwater vehicle proposed by Zhejiang University. In order to determine whether its controllability meets the design requirements, a singularity-free unit quaternion stable control method is used for simulating the AUH performance in MATLAB, including its force and trajectory under different types...
Utilization of Autonomous Surface Vessel (ASV) technology on hydrographic surveys in the Arctic result in significant time savings to field operations while simultaneously improving safety and providing more capability.
In order to analyze the dynamic performance of a Remotely Operated Vehicle (ROV) during mission like ship hull inspection, it is necessary to establish the 6 degree-of-freedom equations of motion considering well modeled hydrodynamic force acting on a ROV. Typically, the hydrodynamic force is the model by polynomial functions and those coefficients are obtained by captive model tests or empirical...
As part of the NEDO robot project, we are engaged in developing a surface/underwater robot system which investigates underwater infrastructure such as dams and river facilities. In this paper, we propose a sailing control method based on “extended kite flying principle” for a moored unmanned surface vehicle (USV) system in running water. We also develop the mooring system and the miniaturized USV...
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