http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Coupled Model Simulation of Wind Stress Effect on Far Wakes of Ships in SAR Images
Fujimura, Atsushi,Soloviev, Alexander,Shin Hyung Rhee,Romeiser, Roland IEEE 2016 IEEE transactions on geoscience and remote sensing Vol.54 No.5
<P>A high-resolution 3-D hydrodynamic model capable of simulating far wakes of ships has been implemented using computational fluid dynamics software. We feed the surface velocity field produced by the hydrodynamic model into a numerical radar imaging model to simulate synthetic aperture radar (SAR) signatures of the wake. Potential capabilities of this modeling method are demonstrated for an example of wind stress effects on the centerline (turbulent) ship wake. The numerical simulations show that an interaction of the wind-induced surface current with circulations in the ship wake results in a convergence zone on the upwind side of the centerline wake and a divergence zone on the downwind side. In the simulated radar image, the convergence zone appears to be bright because of enhanced surface roughness and radar backscattering. The divergence zone looks dark due to an attenuation of short gravity capillary waves and a corresponding reduction of the backscattered power. This combined hydrodynamic and radar imaging model predicts an asymmetry of the centerline wake with respect to the wind direction, which is consistent with observed ship wake signatures in high-resolution satellite SAR images. The approach developed in this work could be also useful for simulations of other natural and artificial fine-scale features on the sea surface (sharp frontal interfaces, freshwater plumes, etc.) and their interpretation in high-resolution SAR imagery.</P>
Research of Graph-analytical Methods for a Vehicle Motion Planning
Igor Shapovalov,Victor Soloviev,Valeriy Finaev,Evgeny Kosenko,Jury Zargaryan 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10
In this paper we present the results of research on the efficiency of graph-analytical methods for vehicle motion trajectory planning under uncertainties. The three most common graph-analytical methods were considered: potential fields, algorithms based on Voronoi diagrams, and A*-algorithm combined with the method of dynamic window. We proved the applicability of the considered methods to the problems of trajectory planning for complex dynamical objects on the example of the quadrotor flight control. The testing of the considered graph-analytical methods efficiency was carried out by simulation of the quadrotor horizontal flight through four maps with different number and location of obstacles. Moreover, initially the control system of the vehicle does not have any information about obstacles. The trajectories are created during the motion on the basis of new information about the map. As a result, it was concluded that all methods can be used in uncertain environments for the control of complex dynamical objects of quadrotor type.
Group robot control in non-deterministic environments using the potential field method
D.A. Beloglazov,V.I. Finaev,A.E. Titov,I.O. Shapovalov,V.V. Soloviev 제어로봇시스템학회 2016 제어로봇시스템학회 국제학술대회 논문집 Vol.2016 No.10
The main purpose of this paper is to describe the method of group robot control in non-deterministic environments. Here the group structure is proposed for creation with the use of space lattice concept minimizing the computational cost for robot to determine its spatial position in the ranks of the structure. The stages of the solution of two interrelated tasks of robot group motion organization using the method of potential fields are considered: task of trajectory planning of the group considered as a uniform structure in the global coordinate space and the task of planning of the individual trajectory of each mobile robot in the considered structure. As main results, we propose the concept of structure formation for the robot groups using the space lattice and the algorithm of group robot control. To confirm the efficiency of our method we presented some simulation results with the groups including up to five autonomous mobile robots.