超声测距中的伪随机码渡越时间的捕获  

Time of Flight Capture in Ultrasonic Pseudo Random Number Distance Measurement

作　　者：黄增荣[1] 秦会斌[1] 黄博志[1] 

机构地区：[1]杭州电子科技大学CAE研究所,杭州310018

出　　处：《传感技术学报》2006年第3期843-846,共4页Chinese Journal of Sensors and Actuators

摘　　要：采用数字相关的方法确定超声波测距中的渡越时间。借助于一个经过适当选择的伪随机序列信号作为超声波的发射信号,可以通过数字相关方法求出发射序列和接收序列的相位差,即渡越时间。本文在计算自相关函数时放弃了快速傅立叶变换(FFT)算法,省去了乘法运算,取而代之的是只用异或和加法的并行数字相关技术,它显著地减少了数据处理时间和FPGA资源。系统以Altera公司的quartusⅡ为开发平台,经逻辑综合、布局布线后,适配到FPGA芯片中,给出了仿真结果。Digital correlation approach is used to find the time of flight（tof） in ultrasonic distance measurement. With the help of an adequately chosen Pseudo random Number （PN） as transmitting signal of the ultrasonic sensor, the time of flight can be got by using digital correlation approach to fine the phase difference between transmitting sequence and receiving sequence. The correlation function is computed by using xor and add operation taking place of FFT algorithm using multiplication. This method shortens the processing time and FPGA resource. The system design is based on Aletra＇s quartus Ⅱ software, and described by VHDL language and be fitted to FPGA chip after logic synthesizing and placement routing. The timing simulation result in placement and routing is also presented.

关 键 词：超声测距 渡越时间 数字相关器 VHDL语言 

分 类 号：TP212.1[自动化与计算机技术—检测技术与自动化装置]