摘要
针对常规超声波局部定位系统的缺陷,介绍了类GPS超声定位系统及其工作原理;为了识别系统中的各个基站,给每个基站分配一个单独的伪随机码;研究了自主导引小车与单基站的距离估计问题,建立了超声扩频测距时延估计模型,根据此模型提出并详细推导了基于FFT的单基站距离估计算法;实践表明,经过上述算法处理后,当接收信号与参考信号所用m序列相同时,它们的包络相关函数在时延处有一个尖锐的相关值;当所用m序列不同时,它们的包络相关函数没有突出的相关值,从而达到识别各个基站的目的。
In view of the deficiencies of the conventional ultrasonic location system, Quasi-GPS ultrasonic ranging system and its work principle are introduced. In order to identify each base-station in quasi-GPS ultrasonic location system, a unique pseudo-random code is assigned to each base-station. The distance estimation problem between Autonomous Guide Vehicle （AGV） and single base-station is studied, and then the ultrasonic spread- spectrum distance measurement Time Delay Estimation （TDE） model is established. Based on the above model, the single base-station distance estimation algorithm based on FFT is presented and analyzed. It shows by experiments that when the m sequence used in the received-echo is as same as the reference-echo, there will be a sharp correlation value in their envelope correlation function after they are processed by the above algorithm; otherwise, there will be no prominent correlation value. So, the AGV can identify each base-station easily.
出处
《计算机测量与控制》
CSCD
2007年第5期648-650,共3页
Computer Measurement &Control
关键词
类GPS
超声定位
时延估计
快速傅立叶变换
quasi-GPS
ultrasonic location
time delay estimation
fast fourier transform
