公用网应用于GPS车辆定位系统数据传输的分析研究

自动车辆定位系统AVL(automatic vehicle location)是整个ITS(智能交通系统)的基础,GPS(全球定位系统)非常适合于车辆定位.文章介绍了GPS车辆定位系统的原理、功能,指出了GPS车辆定位系统的数据传输问题,并针对这一问题,以GPRS(通用无线分组服务)为例,论述了公用网对这一问题的解决方法.     

The Modified Multiple Model Switching Tuning Control Application in AVC

In the complex mechanical vibration environment, the dominant frequency of the system varies remarkably and swiftly under various running conditions, which also characterizes uncertainty and time-variation. It is very impending and important to suppress or isolate the detrimental vibrations related to the above memtoned system with active vibration control (AVC) technology. This paper presented the improved linear quadratic gaussian (LQG) control scheme with a specified filter to realize broadband disturbance/noise attenuation and assure intensive suppression of vibration at the key vibration frequency, then applies and modifies the multiple model switching tuning (MMST) control method by disturbance observation to track the variation of dominant vibration component timely. The effectiveness and superiority of the presented control method were demonstrated by numerical simulation and AVC experiment on a flexible cantilever beam under sweeping excitation.