针对通用视频监控系统对网络要求高的现状,本文设计了一种基于低功耗物联网野外视频监控技术的视频监控系统。本系统以基于Linux操作系统的Raspberry Pi 3B+开发板作为嵌入式平台,通过网线搭载海康威视网络摄像头,在PC机上使用C#进行图...针对通用视频监控系统对网络要求高的现状,本文设计了一种基于低功耗物联网野外视频监控技术的视频监控系统。本系统以基于Linux操作系统的Raspberry Pi 3B+开发板作为嵌入式平台,通过网线搭载海康威视网络摄像头,在PC机上使用C#进行图形界面开发,接收和显示采集到的每一帧图像,实现了可视化监控的功能,根据需求可以将视频以MP4格式进行保存。展开更多
目前,中小学生的人身安全问题已经引起人们的高度重视.本文主要研究基于移动端的追踪定位系统,主要用于定位学生所在位置并引导教师和家长准确到达学生所在目的地。本系统采用Raspberry Pi 4B作为控制主板,利用其双频无线局域网和蓝牙...目前,中小学生的人身安全问题已经引起人们的高度重视.本文主要研究基于移动端的追踪定位系统,主要用于定位学生所在位置并引导教师和家长准确到达学生所在目的地。本系统采用Raspberry Pi 4B作为控制主板,利用其双频无线局域网和蓝牙接口进行数据接收,利用2.4G频带进行数据传输,并且在数据传输至云端服务器后进行及时处理和响应。展开更多
Setting engine emission targets to meet diesel car requirements is particularly important in engine performance development phase. Many researches are focused on associating vehicle performance with engine targets, bu...Setting engine emission targets to meet diesel car requirements is particularly important in engine performance development phase. Many researches are focused on associating vehicle performance with engine targets, but most work is done by testing, which is time and cost consuming, furthermore, the relationship of vehicle and engine will change when either engine or vehicle changes. A GT-Drive model to simulate New European Driving Cycle (NEDC) for passenger car is developed and calibrated by testing data, model precision is controlled within 5%. Time distribution of engine operating conditions when car running NEDC cycle has been analyzed, 10 critical major engine operating points are summarized according to running time proportion. Emission of NOx and smoke control regions containing these 10 points for target engine are set. Vehicle emissions are simulated and evaluated during engine development after engine performance test data are got, and engine combustion system layout and calibration are adjusted until vehicle targets are met. Vehicle is tested in chassis dynamometer finally, the testing results show a good agreement with the simulated results with an error of less than 5%, which proves that the emission value exchange of vehicle and engine is reliable. Performance target decomposition method for passenger car diesel presented can greatly shorten the development cycle and save costs.展开更多
文摘针对通用视频监控系统对网络要求高的现状,本文设计了一种基于低功耗物联网野外视频监控技术的视频监控系统。本系统以基于Linux操作系统的Raspberry Pi 3B+开发板作为嵌入式平台,通过网线搭载海康威视网络摄像头,在PC机上使用C#进行图形界面开发,接收和显示采集到的每一帧图像,实现了可视化监控的功能,根据需求可以将视频以MP4格式进行保存。
文摘目前,中小学生的人身安全问题已经引起人们的高度重视.本文主要研究基于移动端的追踪定位系统,主要用于定位学生所在位置并引导教师和家长准确到达学生所在目的地。本系统采用Raspberry Pi 4B作为控制主板,利用其双频无线局域网和蓝牙接口进行数据接收,利用2.4G频带进行数据传输,并且在数据传输至云端服务器后进行及时处理和响应。
基金supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2008AA11A115)
文摘Setting engine emission targets to meet diesel car requirements is particularly important in engine performance development phase. Many researches are focused on associating vehicle performance with engine targets, but most work is done by testing, which is time and cost consuming, furthermore, the relationship of vehicle and engine will change when either engine or vehicle changes. A GT-Drive model to simulate New European Driving Cycle (NEDC) for passenger car is developed and calibrated by testing data, model precision is controlled within 5%. Time distribution of engine operating conditions when car running NEDC cycle has been analyzed, 10 critical major engine operating points are summarized according to running time proportion. Emission of NOx and smoke control regions containing these 10 points for target engine are set. Vehicle emissions are simulated and evaluated during engine development after engine performance test data are got, and engine combustion system layout and calibration are adjusted until vehicle targets are met. Vehicle is tested in chassis dynamometer finally, the testing results show a good agreement with the simulated results with an error of less than 5%, which proves that the emission value exchange of vehicle and engine is reliable. Performance target decomposition method for passenger car diesel presented can greatly shorten the development cycle and save costs.
