In this paper, a novel algorithm based on disturbed fluid and trajectory propagation is developed to solve the three-dimensional（3-D） path planning problem of unmanned aerial vehicle（UAV） in static environment.Fir...In this paper, a novel algorithm based on disturbed fluid and trajectory propagation is developed to solve the three-dimensional（3-D） path planning problem of unmanned aerial vehicle（UAV） in static environment.Firstly, inspired by the phenomenon of streamlines avoiding obstacles, the algorithm based on disturbed fluid is developed and broadened.The effect of obstacles on original fluid field is quantified by the perturbation matrix, where the tangential matrix is first introduced.By modifying the original flow field, the modified one is then obtained, where the streamlines can be regarded as planned paths.And the path proves to avoid all obstacles smoothly and swiftly, follow the shape of obstacles effectively and reach the destination eventually.Then, by considering the kinematics and dynamics equations of UAV, the method called trajectory propagation is adopted to judge the feasibility of the path.If the planned path is unfeasible, repulsive and tangential parameters in the perturbation matrix will be adjusted adaptively based on the resolved state variables of UAV.In most cases, a flyable path can be obtained eventually.Simulation results demonstrate the effectiveness of this method.展开更多
This paper is concerned with the generation of waves due to initial disturbances at the upper surface of a two-layer fluid, as the upper layer is covered by an inertial surface and the lower layer extends infinitely d...This paper is concerned with the generation of waves due to initial disturbances at the upper surface of a two-layer fluid, as the upper layer is covered by an inertial surface and the lower layer extends infinitely downwards. The inertial surface is composed of thin but uniform distribution of non-interacting material. In the mathematical analysis, the Fourier and Laplace transform techniques have been utilized to obtain the depressions of the inertial surface and the interface in the form of infinite integrals. For initial disturbances concentrated at a point, the inertial surface depression and the interface depression are evaluated asymptotically for large time and distance by using the method of stationary phase. They are also depicted graphically for two types of initial disturbances and appropriate conclusions are made.展开更多
基金supported by the National Natural Science Foundation of China (No.61175084)the Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China (No.IRT13004)
文摘In this paper, a novel algorithm based on disturbed fluid and trajectory propagation is developed to solve the three-dimensional（3-D） path planning problem of unmanned aerial vehicle（UAV） in static environment.Firstly, inspired by the phenomenon of streamlines avoiding obstacles, the algorithm based on disturbed fluid is developed and broadened.The effect of obstacles on original fluid field is quantified by the perturbation matrix, where the tangential matrix is first introduced.By modifying the original flow field, the modified one is then obtained, where the streamlines can be regarded as planned paths.And the path proves to avoid all obstacles smoothly and swiftly, follow the shape of obstacles effectively and reach the destination eventually.Then, by considering the kinematics and dynamics equations of UAV, the method called trajectory propagation is adopted to judge the feasibility of the path.If the planned path is unfeasible, repulsive and tangential parameters in the perturbation matrix will be adjusted adaptively based on the resolved state variables of UAV.In most cases, a flyable path can be obtained eventually.Simulation results demonstrate the effectiveness of this method.
基金Supported by the DST Research Project No.SR/SY/MS:521/08and CSIR,New Delhi
文摘This paper is concerned with the generation of waves due to initial disturbances at the upper surface of a two-layer fluid, as the upper layer is covered by an inertial surface and the lower layer extends infinitely downwards. The inertial surface is composed of thin but uniform distribution of non-interacting material. In the mathematical analysis, the Fourier and Laplace transform techniques have been utilized to obtain the depressions of the inertial surface and the interface in the form of infinite integrals. For initial disturbances concentrated at a point, the inertial surface depression and the interface depression are evaluated asymptotically for large time and distance by using the method of stationary phase. They are also depicted graphically for two types of initial disturbances and appropriate conclusions are made.
