This paper presents a 3D simulator used for studying the motion control and autonomous navigation of robotic fish. The simulator’s system structure and computation flow are presented. Simplified kinematics and hydrod...This paper presents a 3D simulator used for studying the motion control and autonomous navigation of robotic fish. The simulator’s system structure and computation flow are presented. Simplified kinematics and hydrodynamics models for a virtual robotic fish are proposed. Many other object models are created for water, obstacles, sonar sensors and a swimming pool. Experimental results show that the simulator provides a realistic and convenient way to develop autonomous navigation algorithms for robotic fish.展开更多
A bionic experimental platform was designed for the purpose of investigating time accurate three-dimensional flow field, using digital particle image velocimetry （DSPIV）. The wake behind the flapping trail of a robo...A bionic experimental platform was designed for the purpose of investigating time accurate three-dimensional flow field, using digital particle image velocimetry （DSPIV）. The wake behind the flapping trail of a robotic fish model was studied at high spatial resolution. The study was performed in a water channel. A robot fish model was designed and built. The model was fixed onto a rigid support frame- work using a cable-supporting method, with twelve stretched wires. The entire tail of the model can perform prescribed motions in two degrees of freedom, mainly in carangiform mode, by driving its afterbody and lunate caudal fin respectively. The DSPIV system was set up to operate in a trans- lational manner, measuring velocity field in a series of parallel slices. Phase locked measurements were repeated for a number of runs, allowing reconstruction of phase average flow field. Vortex structures with phase history of the wake were obtained. The study reveals some new and complex three-dimensional flow structures in the wake of the fish, including ＂reverse hairpin vortex＂ and ＂reverse Karman S-H vortex rings＂, allowing insight into physics of this complex flow.展开更多
The stability and evolution of human genetics depend on chromosomes and chromosome-chromosome interactions.We wish to understand the spatial location of chromosomes in dividing cells in order to understand the relatio...The stability and evolution of human genetics depend on chromosomes and chromosome-chromosome interactions.We wish to understand the spatial location of chromosomes in dividing cells in order to understand the relationship between chromosome-chromosome interactions and to further investigate the role of chromosomes and their impact on cell biological behavior.In this study,we explored the relative spatial positional relationships of chromosomes[t(9;22)and t(15;17)]in B-ALL cells by using the three-dimensional DNA fluorescent in situ hybridization(3D-FISH)method.The results showed that chromosomes[t(9;22)and t(15;17)]showed relatively stable spatial relationships.The relative stability of the spatial location of chromosomes in dividing cells may be relevant to disease.展开更多
为提高鱼类行为学数据的提取效率,实验提出了一种基于单摄像机的鱼类三维观测方法,将防水镜面安装在实验用鱼缸上方,模拟一台由上向下拍摄的摄像机,实现了单摄像机三维成像。同时运用多目标跟踪的IMMJPDA(interacting multiple model jo...为提高鱼类行为学数据的提取效率,实验提出了一种基于单摄像机的鱼类三维观测方法,将防水镜面安装在实验用鱼缸上方,模拟一台由上向下拍摄的摄像机,实现了单摄像机三维成像。同时运用多目标跟踪的IMMJPDA(interacting multiple model joint probabilistic data association)算法,实现了鱼类运动的三维实时自动跟踪,并通过摄像机倾斜矫正和摄像机标定提高了测量精度。通过对6条红鼻剪刀鱼的跟踪,实验结果显示:本方法可正确区分、提取和跟踪鱼群个体以及它们的镜像,自动输出鱼的三维坐标、实时速度、方向等参数,并生成完整的鱼类行为三维轨迹图。展开更多
文摘This paper presents a 3D simulator used for studying the motion control and autonomous navigation of robotic fish. The simulator’s system structure and computation flow are presented. Simplified kinematics and hydrodynamics models for a virtual robotic fish are proposed. Many other object models are created for water, obstacles, sonar sensors and a swimming pool. Experimental results show that the simulator provides a realistic and convenient way to develop autonomous navigation algorithms for robotic fish.
基金supported by the National Natural Science Foundation of China (10772017 and 10472011)BUAA-985 Foundation
文摘A bionic experimental platform was designed for the purpose of investigating time accurate three-dimensional flow field, using digital particle image velocimetry （DSPIV）. The wake behind the flapping trail of a robotic fish model was studied at high spatial resolution. The study was performed in a water channel. A robot fish model was designed and built. The model was fixed onto a rigid support frame- work using a cable-supporting method, with twelve stretched wires. The entire tail of the model can perform prescribed motions in two degrees of freedom, mainly in carangiform mode, by driving its afterbody and lunate caudal fin respectively. The DSPIV system was set up to operate in a trans- lational manner, measuring velocity field in a series of parallel slices. Phase locked measurements were repeated for a number of runs, allowing reconstruction of phase average flow field. Vortex structures with phase history of the wake were obtained. The study reveals some new and complex three-dimensional flow structures in the wake of the fish, including ＂reverse hairpin vortex＂ and ＂reverse Karman S-H vortex rings＂, allowing insight into physics of this complex flow.
文摘The stability and evolution of human genetics depend on chromosomes and chromosome-chromosome interactions.We wish to understand the spatial location of chromosomes in dividing cells in order to understand the relationship between chromosome-chromosome interactions and to further investigate the role of chromosomes and their impact on cell biological behavior.In this study,we explored the relative spatial positional relationships of chromosomes[t(9;22)and t(15;17)]in B-ALL cells by using the three-dimensional DNA fluorescent in situ hybridization(3D-FISH)method.The results showed that chromosomes[t(9;22)and t(15;17)]showed relatively stable spatial relationships.The relative stability of the spatial location of chromosomes in dividing cells may be relevant to disease.
文摘为提高鱼类行为学数据的提取效率,实验提出了一种基于单摄像机的鱼类三维观测方法,将防水镜面安装在实验用鱼缸上方,模拟一台由上向下拍摄的摄像机,实现了单摄像机三维成像。同时运用多目标跟踪的IMMJPDA(interacting multiple model joint probabilistic data association)算法,实现了鱼类运动的三维实时自动跟踪,并通过摄像机倾斜矫正和摄像机标定提高了测量精度。通过对6条红鼻剪刀鱼的跟踪,实验结果显示:本方法可正确区分、提取和跟踪鱼群个体以及它们的镜像,自动输出鱼的三维坐标、实时速度、方向等参数,并生成完整的鱼类行为三维轨迹图。
