Ultrasonic distance measurement system with high precision based on AT89C51 microprocessor

A high-precision ultrasonic distance measurement system is designed in this paper.The structure and functions of the system,the working principle of the circuit,the design of software and experiment results are given.The system uses cost-effective AT89C51 as controller.Some improvement solutions are supplied,such as a temperature compensation circuit,a receiving circuit with dual comparators and a system delay time correcting circuit,to overcome the shortcomings of low accuracy of some existing distance measuring systems.The test results show that the distance measuring error of system can be lower than 1% within 0.4m～5m range.So it can be applied to the occasions of high-precision requirements.