Research And Implementation Of Ultrasonic Distance Measurement System

Ultrasonic is applied widely into the non-contact measurements,including ultrasonic distance measurement,ultrasonic thickness measurement,ultrasonic positioning and so on,due to it being characterized by good directivity,strong capacity of anti-interference and reflection,directional transmission and less attenuation during the flight.Among them,ultrasonic liquid height measurement is highly applied in agriculture.Therefore,precise liquid height measurement is an important part of the agricultural process control.As to the measurement of big water pool,this paper researched and implemented a liquid height measurement system with the advantages of easy operation,precise measurement,intelligent management and lower costs.To raise the precision of ultrasonic distance measurement,this paper researched the basic method and theory using TOF(time of flight),analyses the main factors affecting the precision and proposed the general design project of ultrasonic distance measurement system.And it accomplished the hardware circuit,including SCM(Single-chip Microprocessor)minimum system,ultrasonic transmitting and receiving circuits,actuator direction control circuit,wireless communication circuit,liquid-crystal display circuit and sound and light alarm circuit.According to the logical relationship of the distance measurement system,the flow chart was drawn and the system software was implemented using C program language.Specifically,using the Kalman filter algorithm is to estimate the next measurement height to adjust the range automatically and using the standard baffle to measure and compute precisely the speed of spread with a single one ultrasonic sensor to get the liquid height.At last,the ultrasonic distance measurement system was done to analyze the results and error factors based on it.The actual measurement results show that the system meets the each specified technique target and is advantaged with simple hardware structure,low cost,high precision and so on,and implements the functions of real-time display of liquid height and alarm.