基于伪随机序列自相关的多传感器测距系统

摘要

针对单脉冲回拨方式的超声测距方法存在抗干扰能力差和不能全方位检测环境信息等缺陷,开发了一种多传感器测距系统.该多传感器超声测距系统基于伪随机序列自相关原理,通过对发射信号和回波信号进行相关运算精确的捕捉其相位差来计算渡越时间.以现场可编程门阵列(FPCA)为核心器件,结合超声回波的特点设计了能抑制和隔离电路中噪声的回波微弱信号接收电路、多路模数转换电路和相应的软件系统；提出了适用于该系统的误差校正方法.FPGA仿真结果表明,在误码存在的情况下,设计的基于自相关的回波信号识别系统可以很准确的消除超声串扰和计算出渡越时间.%Aimed at the poor capacity of resisting disturbance and cannot comprehensive testing environment information of signal echo ultrasonic distance measurement, a multi-sensor ranging system was developed, which based on the self-correlation of pseudo-random sequence. To capturing the phase difference precisely to calculate the time of flight by correlation operation sending wave and receive wave. Taking FPGA as the core of controller,combined with the characteristics of ultrasonic echo,weak signal receiving circuit for ultrasonic echo which can inhibit and isolating circuit,multi-channel digital converter circuit and the corresponding software system were designed. An error correction algorithm for this ultrasonic ranging system was proposed. The results of FPGA simulation demonstrate, in the presence of error, that the echo signal recognition system based on self-correlation can eliminate crosstalk and calculated the time of flight precisely.