顾及城市规划、建设、管理等政府部门需求,结合城市空间基础数据实际情况,基于三维GIS(geographic information system)开发了地上地下一体化三维系统。研究了多模态时空数据集成管理、地下三维管线自动建模、工程地质建模分析、城市空...顾及城市规划、建设、管理等政府部门需求,结合城市空间基础数据实际情况,基于三维GIS(geographic information system)开发了地上地下一体化三维系统。研究了多模态时空数据集成管理、地下三维管线自动建模、工程地质建模分析、城市空间产权管理关键技术和功能,为城市实景三维场景组织调度、地下空间可视化应用以及城市立体空间精细化管理提供决策支持。以成都市数据为例,验证了系统的可行性和有效性。展开更多
为研究挖掘机斜盘式轴向柱塞泵的压力、流量特性以及工作过程中出现供油压力不足现象的原因,结合轴向柱塞泵的工作原理,建立泵体主要部件的数学模型.利用多学科领域工程系统仿真高级建模环境(Advanced Modeling Environment for Simulat...为研究挖掘机斜盘式轴向柱塞泵的压力、流量特性以及工作过程中出现供油压力不足现象的原因,结合轴向柱塞泵的工作原理,建立泵体主要部件的数学模型.利用多学科领域工程系统仿真高级建模环境(Advanced Modeling Environment for Simulation of engineering systems,AMESim)软件,建立泵体各部件及整体仿真模型;经过连续调试、运行,合理配置参数,进行系统仿真;以柱塞泵瞬时流量最优时发动机转速和斜盘倾角参数为基准进行优化,并得到接近恒压力特性的结果.该方法可为实际设计提供理论依据和参考,缩短研发周期,加快产品的市场投入.展开更多
Model reconstruction from points scanned on existing physical objects is much important in a variety of situations such as reverse engineering for mechanical products, computer vision and recovery of biological shapes...Model reconstruction from points scanned on existing physical objects is much important in a variety of situations such as reverse engineering for mechanical products, computer vision and recovery of biological shapes from two dimensional contours. With the development of measuring equipment, cloud points that contain more details of the object can be obtained conveniently. On the other hand, large quantity of sampled points brings difficulties to model reconstruction method. This paper first presents an algorithm to automatically reduce the number of cloud points under given tolerance. Triangle mesh surface from the simplified data set is reconstructed by the marching cubes algorithm. For various reasons, reconstructed mesh usually contains unwanted holes. An approach to create new triangles is proposed with optimized shape for covering the unexpected holes in triangle meshes. After hole filling, watertight triangle mesh can be directly output in STL format, which is widely used in rapid prototype manufacturing. Practical examples are included to demonstrate the method.展开更多
文摘顾及城市规划、建设、管理等政府部门需求,结合城市空间基础数据实际情况,基于三维GIS(geographic information system)开发了地上地下一体化三维系统。研究了多模态时空数据集成管理、地下三维管线自动建模、工程地质建模分析、城市空间产权管理关键技术和功能,为城市实景三维场景组织调度、地下空间可视化应用以及城市立体空间精细化管理提供决策支持。以成都市数据为例,验证了系统的可行性和有效性。
文摘为研究挖掘机斜盘式轴向柱塞泵的压力、流量特性以及工作过程中出现供油压力不足现象的原因,结合轴向柱塞泵的工作原理,建立泵体主要部件的数学模型.利用多学科领域工程系统仿真高级建模环境(Advanced Modeling Environment for Simulation of engineering systems,AMESim)软件,建立泵体各部件及整体仿真模型;经过连续调试、运行,合理配置参数,进行系统仿真;以柱塞泵瞬时流量最优时发动机转速和斜盘倾角参数为基准进行优化,并得到接近恒压力特性的结果.该方法可为实际设计提供理论依据和参考,缩短研发周期,加快产品的市场投入.
文摘Model reconstruction from points scanned on existing physical objects is much important in a variety of situations such as reverse engineering for mechanical products, computer vision and recovery of biological shapes from two dimensional contours. With the development of measuring equipment, cloud points that contain more details of the object can be obtained conveniently. On the other hand, large quantity of sampled points brings difficulties to model reconstruction method. This paper first presents an algorithm to automatically reduce the number of cloud points under given tolerance. Triangle mesh surface from the simplified data set is reconstructed by the marching cubes algorithm. For various reasons, reconstructed mesh usually contains unwanted holes. An approach to create new triangles is proposed with optimized shape for covering the unexpected holes in triangle meshes. After hole filling, watertight triangle mesh can be directly output in STL format, which is widely used in rapid prototype manufacturing. Practical examples are included to demonstrate the method.
