Several different strategies of 3D modeling are a do pted for different kinds of manmade objects. Firstly, for those manmade objects with regular structure, if 2D information is available and elevation information can...Several different strategies of 3D modeling are a do pted for different kinds of manmade objects. Firstly, for those manmade objects with regular structure, if 2D information is available and elevation information can be obtained conveniently, then 3D modeling of them can be executed directly . Secondly, for those manmade objects with complicated structure comparatively a nd related stereo images pair can be acquired, in the light of topology-based 3 D model we finish 3D modeling of them by integrating automatic and semi-automat ic object extraction. Thirdly, for the most complicated objects whose geometrica l information cannot be got from stereo images pair completely, we turn to topol ogical 3D model based on CAD.展开更多
In order to develop the core chip supporting binocular stereo displays for head mounted display (HMD) and glasses-TV, a very large scale integrated (VISI) design scheme is proposed by using a pipeline architecture...In order to develop the core chip supporting binocular stereo displays for head mounted display (HMD) and glasses-TV, a very large scale integrated (VISI) design scheme is proposed by using a pipeline architecture for 3D display processing chip (HMD100). Some key techniques including stereo display processing and high precision video scaling based bicubic interpolation, and their hardware implementations which improve the image quality are presented. The proposed HMD100 chip is verified by the field-programmable gate array (FPGA). As one of innovative and high integration SoC chips, HMD100 is designed by a digital and analog mixed circuit. It can support binocular stereo display, has better scaling effect and integration. Hence it is applicable in virtual reality (VR), 3D games and other microdisplay domains.展开更多
As the running speed of high-speed trains increases, aerodynamic drag becomes the key factor which limits the further increase of the running speed and energy consumption. Aerodynamic lift of the trailing car also bec...As the running speed of high-speed trains increases, aerodynamic drag becomes the key factor which limits the further increase of the running speed and energy consumption. Aerodynamic lift of the trailing car also becomes the key force which affects the amenity and safety of the train. In the present paper, a simplified CRH380A high-speed train with three carriages is chosen as the model in order to optimize aerodynamic drag of the total train and aerodynamic lift of the trailing car. A constrained mul- ti-objective optimization design of the aerodynamic head shape of high-speed trains based on adaptive non-dominated sorting genetic algorithm is also developed combining local function three-dimensional parametric approach and central Latin hypercube sampling method with maximin criteria based on the iterative local search algorithm. The results show that local function parametric approach can be well applied to optimal design of complex three-dimensional aerodynamic shape, and the adaptive non-dominated sorting genetic algorithm can be more accurate and efficient to find the Pareto front. After optimization the aerodynamic drag of the simplified train with three carriages is reduced by 3.2%, and the lift coefficient of the trailing car by 8.24%, the volume of the streamlined head by 2.16%; the aerodynamic drag of the real prototype CRH380A is reduced by 2.26%, lift coefficient of the trailing car by 19.67%. The variation of aerodynamic performance between the simplified train and the true train is mainly concentrated in the deformation region of the nose cone and tail cone. The optimization approach proposed in the present paper is simple yet efficient, and sheds lights on the constrained multi-objective engineering optimization design of aerodynamic shape of high-speed trains.展开更多
文摘Several different strategies of 3D modeling are a do pted for different kinds of manmade objects. Firstly, for those manmade objects with regular structure, if 2D information is available and elevation information can be obtained conveniently, then 3D modeling of them can be executed directly . Secondly, for those manmade objects with complicated structure comparatively a nd related stereo images pair can be acquired, in the light of topology-based 3 D model we finish 3D modeling of them by integrating automatic and semi-automat ic object extraction. Thirdly, for the most complicated objects whose geometrica l information cannot be got from stereo images pair completely, we turn to topol ogical 3D model based on CAD.
文摘In order to develop the core chip supporting binocular stereo displays for head mounted display (HMD) and glasses-TV, a very large scale integrated (VISI) design scheme is proposed by using a pipeline architecture for 3D display processing chip (HMD100). Some key techniques including stereo display processing and high precision video scaling based bicubic interpolation, and their hardware implementations which improve the image quality are presented. The proposed HMD100 chip is verified by the field-programmable gate array (FPGA). As one of innovative and high integration SoC chips, HMD100 is designed by a digital and analog mixed circuit. It can support binocular stereo display, has better scaling effect and integration. Hence it is applicable in virtual reality (VR), 3D games and other microdisplay domains.
基金supported by the Major State Basic Research Development Program of China ("973" Program) (Grant No. 2011CB711100) National Key Technology R&D Program (Grant No. 2009BAQG12A03)
文摘As the running speed of high-speed trains increases, aerodynamic drag becomes the key factor which limits the further increase of the running speed and energy consumption. Aerodynamic lift of the trailing car also becomes the key force which affects the amenity and safety of the train. In the present paper, a simplified CRH380A high-speed train with three carriages is chosen as the model in order to optimize aerodynamic drag of the total train and aerodynamic lift of the trailing car. A constrained mul- ti-objective optimization design of the aerodynamic head shape of high-speed trains based on adaptive non-dominated sorting genetic algorithm is also developed combining local function three-dimensional parametric approach and central Latin hypercube sampling method with maximin criteria based on the iterative local search algorithm. The results show that local function parametric approach can be well applied to optimal design of complex three-dimensional aerodynamic shape, and the adaptive non-dominated sorting genetic algorithm can be more accurate and efficient to find the Pareto front. After optimization the aerodynamic drag of the simplified train with three carriages is reduced by 3.2%, and the lift coefficient of the trailing car by 8.24%, the volume of the streamlined head by 2.16%; the aerodynamic drag of the real prototype CRH380A is reduced by 2.26%, lift coefficient of the trailing car by 19.67%. The variation of aerodynamic performance between the simplified train and the true train is mainly concentrated in the deformation region of the nose cone and tail cone. The optimization approach proposed in the present paper is simple yet efficient, and sheds lights on the constrained multi-objective engineering optimization design of aerodynamic shape of high-speed trains.