ABSTRACT: Ranging technology is a very convenient way of non-contact measurement. This article is based on SCM system composed of ultrasonic range finder carried out a detailed introduction.
Single chip microcomputer AT89C51 is control core in the system ,and the voice circuit of the system is composed of voice chip ISD2590 ,which realizes that the measuring result s are calculated in real-time, and ultrasonic ranging analysis of the principles on the basis that the range finder design ideas and issues to be considered, given the realization of ultrasonic ranging hardware design and Software design. There is the propagation velocity of the ultrasonic varying with the environmental temperature. In order to accurately calculate the real-time propagation velocity of the ult rasonic ,the system measures the environmental temperature by the DS18B20 temperature sensor.The design of the system after correction, the measurement accuracy of 0.01 meters.
To increase the accuracy in measuring farther distance ,automatic gain cont rol circuit s have been designed. To reduce the accidental factors influencing the measuring result s ,the average value of every ten measurement s is taken as the accurate result The practice result shows that the range finder has high measuring precision and very high generalizing value.
Key words: ultrasound; ISD2590 ; AT89C51; DS18B20
