The paper describes the feasibility and method of the application of virtual reality technology to grinding process, and introduces the modeling method of object entity in the environment of virtual reality. The simul...The paper describes the feasibility and method of the application of virtual reality technology to grinding process, and introduces the modeling method of object entity in the environment of virtual reality. The simulation process of grinding wheels and ground surface roughness is discussed, and the computation program system of numerical simulation is compiled with Visual C++ programming language. At the same time, the three-dimensional simulation models of grinding wheels and ground surface roughness are made with OpenGL tool. The choice of grinding wheels, the forecast of ground surface quality and some simulation results can be realized by interactively inputting grinding parameters. The paper applies virtual reality technology to grinding process,makes the model of virtual grinding wheel and simulates the grinding process. The roughness of ground surface is showed in three-dimensional images, and therefore the grinding technology is studied. Computer simulation can not only be used as a shortcut to analyze and research the grinding process, but also increase the research scope and content. The virtual reality technology used in the paper is an advanced visualized simulation with interaction. The surface roughness Ra on simulated ground workpiece can be calculated by the arithmetic average of contour warp absolute value in sampling length of simulated ground workpiece. The parameters of virtual wheel and simulated grinding process can be changed by interaction input, so the simulated results in the desired grinding condition are gained. The effect of each parameter to ground surface can be analyzed by comparing the grinding results in different condition.展开更多
Long-time driving and monotonous visual environment increase the safety risk of driving in an extra-long tunnel.Driving fatigue can be effectively relieved by setting the visual fatigue relief zone in the tunnel.Howev...Long-time driving and monotonous visual environment increase the safety risk of driving in an extra-long tunnel.Driving fatigue can be effectively relieved by setting the visual fatigue relief zone in the tunnel.However,the setting form of visual fatigue relief zone,such as its length and location,is difficult to be designed and quantified.By integrating virtual reality(VR)apparatus with wearable electroencephalogram(EEG)-based devices,a hybrid method was proposed in this study to assist analyzers to formulate the layout of visual fatigue relief zone in the extra-long tunnel.The virtual environment of this study was based on an 11.5 km extra-long tunnel located in Yunnan Province in China.The results indicated that the use of natural landscape decoration inside the tunnel could improve driving fatigue with the growth rate of attention of the driver increased by more than 20%.The accumulation of driving fatigue had a negative effect on the fatigue relief.The results demonstrated that the optimal location of the fatigue relief zone was at the place where driving fatigue had just occurred rather than at the place where a certain amount of driving fatigue had accumulated.展开更多
The pincipl of a 6 DOF (degress of freedom) input device using ultrasonic distance measurement is presented in this paper. The system employs the method of measuring the time of flight. In addition, some techniques, i...The pincipl of a 6 DOF (degress of freedom) input device using ultrasonic distance measurement is presented in this paper. The system employs the method of measuring the time of flight. In addition, some techniques, including automatic gain control, self-adaptive variable threshold and temperature compensation, are also used to improve precision. Then, the positions and orientation of the input device can be calculated by the method of spatial analytic geometry. Meanwhile, commands from the 3-D input device are detected and carried out. The validity and precision of the input device are verified by the experiment in a robot system. The proposed device not only can be used for end effector position and orientation measurement in telerobotics, but also can be an interactive device in virtual reality systems, such as helmet tracking, viewpoint navigation and object manipulation.展开更多
以北京市四惠枢纽为研究对象,探索以数据驱动为导向满足乘客需求的枢纽动态导向标识方案评估及优化设计方法。首先,搭建KANO乘客需求模型,通过桌面实验,形成动态导向标识在内容、样式及空间位置上的优化设计方案,与四惠枢纽现有方案形...以北京市四惠枢纽为研究对象,探索以数据驱动为导向满足乘客需求的枢纽动态导向标识方案评估及优化设计方法。首先,搭建KANO乘客需求模型,通过桌面实验,形成动态导向标识在内容、样式及空间位置上的优化设计方案,与四惠枢纽现有方案形成对比。其次,基于寻路理论通过建筑信息建模(building information modeling,BIM)+虚拟现实(virtual reality,VR)仿真技术,实现人与枢纽的信息交互,提取新旧导向标识方案作用下乘客寻路过程的特征参数。最后,通过对寻路实验中主客观指标分析可知,被试在新版动态导向标识方案中寻路时间、犯错误点数及迷茫点数显著降低,且新版动态导向标识方案在内容、样式及空间位置上满意度均优于旧版。结果表明:研究搭建BIM+VR的虚拟仿真平台,形成以数据驱动为导向的枢纽动态导向标识方案综合评估及优化设计方法,为枢纽动态导向标识方案设计及合理应用提供技术与理论支撑。展开更多
文摘The paper describes the feasibility and method of the application of virtual reality technology to grinding process, and introduces the modeling method of object entity in the environment of virtual reality. The simulation process of grinding wheels and ground surface roughness is discussed, and the computation program system of numerical simulation is compiled with Visual C++ programming language. At the same time, the three-dimensional simulation models of grinding wheels and ground surface roughness are made with OpenGL tool. The choice of grinding wheels, the forecast of ground surface quality and some simulation results can be realized by interactively inputting grinding parameters. The paper applies virtual reality technology to grinding process,makes the model of virtual grinding wheel and simulates the grinding process. The roughness of ground surface is showed in three-dimensional images, and therefore the grinding technology is studied. Computer simulation can not only be used as a shortcut to analyze and research the grinding process, but also increase the research scope and content. The virtual reality technology used in the paper is an advanced visualized simulation with interaction. The surface roughness Ra on simulated ground workpiece can be calculated by the arithmetic average of contour warp absolute value in sampling length of simulated ground workpiece. The parameters of virtual wheel and simulated grinding process can be changed by interaction input, so the simulated results in the desired grinding condition are gained. The effect of each parameter to ground surface can be analyzed by comparing the grinding results in different condition.
基金Project(2018YFB2101000) supported by the National Key R&D Program of ChinaProject(20YF1451400) supported by Shanghai Sailing Program,ChinaProject(SLDRCE19-A-14) supported by the Research Fund of State Key Laboratory for Disaster Reduction in Civil Engineering,China。
文摘Long-time driving and monotonous visual environment increase the safety risk of driving in an extra-long tunnel.Driving fatigue can be effectively relieved by setting the visual fatigue relief zone in the tunnel.However,the setting form of visual fatigue relief zone,such as its length and location,is difficult to be designed and quantified.By integrating virtual reality(VR)apparatus with wearable electroencephalogram(EEG)-based devices,a hybrid method was proposed in this study to assist analyzers to formulate the layout of visual fatigue relief zone in the extra-long tunnel.The virtual environment of this study was based on an 11.5 km extra-long tunnel located in Yunnan Province in China.The results indicated that the use of natural landscape decoration inside the tunnel could improve driving fatigue with the growth rate of attention of the driver increased by more than 20%.The accumulation of driving fatigue had a negative effect on the fatigue relief.The results demonstrated that the optimal location of the fatigue relief zone was at the place where driving fatigue had just occurred rather than at the place where a certain amount of driving fatigue had accumulated.
文摘The pincipl of a 6 DOF (degress of freedom) input device using ultrasonic distance measurement is presented in this paper. The system employs the method of measuring the time of flight. In addition, some techniques, including automatic gain control, self-adaptive variable threshold and temperature compensation, are also used to improve precision. Then, the positions and orientation of the input device can be calculated by the method of spatial analytic geometry. Meanwhile, commands from the 3-D input device are detected and carried out. The validity and precision of the input device are verified by the experiment in a robot system. The proposed device not only can be used for end effector position and orientation measurement in telerobotics, but also can be an interactive device in virtual reality systems, such as helmet tracking, viewpoint navigation and object manipulation.
文摘以北京市四惠枢纽为研究对象,探索以数据驱动为导向满足乘客需求的枢纽动态导向标识方案评估及优化设计方法。首先,搭建KANO乘客需求模型,通过桌面实验,形成动态导向标识在内容、样式及空间位置上的优化设计方案,与四惠枢纽现有方案形成对比。其次,基于寻路理论通过建筑信息建模(building information modeling,BIM)+虚拟现实(virtual reality,VR)仿真技术,实现人与枢纽的信息交互,提取新旧导向标识方案作用下乘客寻路过程的特征参数。最后,通过对寻路实验中主客观指标分析可知,被试在新版动态导向标识方案中寻路时间、犯错误点数及迷茫点数显著降低,且新版动态导向标识方案在内容、样式及空间位置上满意度均优于旧版。结果表明:研究搭建BIM+VR的虚拟仿真平台,形成以数据驱动为导向的枢纽动态导向标识方案综合评估及优化设计方法,为枢纽动态导向标识方案设计及合理应用提供技术与理论支撑。
