超声波测距系统的研究及其硬件设计

Research and Hardware Design of Ultrasonic Ranging System

基于对现有超声波测距技术的分析比较,文中提出一种具有较高测距精度的测距方法和硬件实现。通过超声波信号包络线上2个阈值点拟合出的直线求得回波前沿时间。由于测距精度同时受限于硬件电路的稳定与处理效果,在此基础上设计了一种基于单电源的信号处理电路。该电路由INA826前级处理电路、Fliege滤波电路、PGA116程控放大电路、包络线检测电路以及双阈值电路构成。实验结果表明该电路的波形处理效果好,且相比双电源系统更加节能。

This paper proposed a ultrasonic ranging method and hardware implementation with relatively high precisionbased on the analysis and comparison of several existing ultrasonic ranging methods.This method uses two threshold points on theultrasonic signal envelope to fit a line to calculate the arrival time of the echo.Besides,a corresponding novel signal processingcircuit with single power was designed,since the ranging accuracy is restricted to the stability and processing effect of traditionalone. It consists of INA826 pre-processing circuit,Fliege filtering circuit,PGA116 programmable amplifying circuit,envelope detec-tion circuit and dual-threshold circuit.The experimental results show that waveform of this circuit treats well and is more energysaving than dual power system.