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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...
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...
A Complex Conjugate (CC) control is implemented with a Proportional-Derivative (PD) controller for WEC devices to improve and optimize power absorbed. Traditionally, CC control has not been realizable due to actual implementation that requires acceleration feedback or exact term cancellation. For the PD implementation, only the stiffness term is employed to modify the impedance and achieve resonance...
The underwater vehicles are always being disturbed by ocean current when they work under the sea. In this paper, the Magnus force of a new type autonomous underwater vehicle (AUV) named “autonomous underwater helicopter (AUH)”, a disk-shaped deep-sea underwater vehicle, was analyzed to help it move away from a deep-sea region with temporary ocean current. The simulation technique of the ANSYS-CFX...
To investigate the seismic behavior of prefabricated segmental bridge column with hybrid system (HSC), an elaborate model of was established based on OpenSees platform. The joint between the column and pile cap in the analytical model was constructed with zero-length elements considering the bond-slip effect. The analytical results of the numerical model were carefully compared with the previous test...
In this paper, a completely numerical simulation model of a tilt rotor helicopter is established. Based on the hierarchical and modular modeling principles, the whole simulation model is finally realized on the Simulink platform. Then a sliding mode variable structure controller based on expansion state observer (ESO) is designed in order to realize the attitude control of this nonlinear and strong...
This paper presents the derivation, in great detail, of the full nonlinear model for a quad-copter, using D'Alembert's principle. The final model is presented in a form suitable for simulation and control. Finally, the quad-copter model is implemented and a simple control law for the attitude and altitude are derived. Numerical results are presented at the end of the paper.
In this paper we propose an approach for the determination of static force characteristic of a plunger-type AC electromagnet using 2D numerical model developed in QuickField software. The attraction electromagnetic force is calculated using Maxwell stress tensor method. The numerical model is an AC magnetics problem coupled with the coil electric circuit. The numerical model has been experimentally...
The paper is dedicated to the study of hydrodynamic effects in the rotors of flow micro-hydropower plants. There was argued the geometry of hydrodynamic profiles of blades efficient in terms of energy conversion efficiency based on which original concepts of hydrodynamic rotors were developed. Using the CAD models of the proposed rotors: there were performed complex CFD simulations of the transient...
Side reservoir can improve electromigration (EM) lifetime of copper interconnects. In this work, finite element method (FEM) simulations for interconnect structures with cathode end-of-line reservoir and side reservoir respectively have been conducted to study the side reservoir effects on EM lifetime. It is demonstrated that side location is most likely to have void failure and side reservoir can...
This paper proposes a distributed hierarchical control strategy for cooperative braking control of connected vehicle platoon with a focus on the car-following interactions between vehicles. To this end, a hierarchical control framework including the leader layer and follower layer is first proposed to illustrate the cooperative mechanism. Then, a distributed hierarchical control strategy is designed...
This study aims to design a locomotion controller with detecting and inhibiting side-slipping and to verify the validity of the proposed method in experiments. This report is written the model occur side slip on each link derive and the approach propose based on this Model. We have expressed the motion in case of side-slip occurs on each link, have controlled side-slip in simulation.
This paper discusses numerical experiments by the fast computation method of hydraulic robot dynamics. This paper shows a new proposed model with a special nondmensional representation which is based on the proposed model. The four methods are compared with each other with respect to computation time.
This paper combines coverage control, random-walk and artificial potential method to deploy multi-copter type Unmanned Aerial Vehicles (UAVs). With the coverage control, it is able to deploy agents in the coverage area with arbitrary distribution based on the purpose of control. However, when initial position of agents concentrates on one location, it could be fallen into the local optimal solution...
Simulation of the planar magnetic actuation of ferromagnetic bodies is proposed and experimentally verified in the framework of the system for precise positioning of miniature passive robots with two degrees of freedom. Major goal of presented development is to balance computational effort of the simulation with complexity of computational problem. Proposed methodology is developed for efficient simulation...
An efficient control of nano-positioning stage remains a challenging task due to the effect of noise and disturbances and nonlinear friction phenomenon which is difficult for both modeling and control. In order to solve this problem, a novel model-free control method is applied to nano-positioning stage to provide the robustness and ability of disturbance rejection. Besides, a feedforward model which...
This paper proposes a method for generating an underactuated bipedal gait without including state jumps during motion. We introduce a model of a point-footed and non-straight-legged biped robot with a reaction wheel attached to the hip joint, and design two controllers; one is a strict output-following control for generating the leg motion during the single-limb support phase, and the other is a discrete-time...
In this paper, we aim to develop a precise bicycle model which captures characteristic bicycle behavior such as contact point motion on a surface, front fork effect and centrifugal force, which affects bicycle stability especially in the low-speed or high-speed case. From a historical viewpoint, some of them have been often neglected in the conventional modeling process, and they have caused instability...
This paper presents a computational framework to identify the effects of wind on the dynamics of a quadrotor unmanned aerial vehicle. Then, using the identified model, the strength and the direction of the wind are estimated with the inertial measurements. The proposed approach is based on a geometric numerical integrator on the special Euclidean group, referred to as a Lie group variational integrator...
The traditional metal plate bending process is difficult to meet the requirements of modern shipbuilding industry, and this paper adopts a new incremental bending process for manufacturing metal plate based on minimum energy principle and dieless forming. This process uses a set of punches and a series of highly adjustable and head rotatable supports to complete the punching process by changing the...
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