Views:0 Author:Site Editor Publish Time: 2020-10-09 Origin:Site
Accuracy of ultrasonic ranging sensor module: ±(1cm+0.5%×distance), which is relatively low. The principle of ultrasonic ranging is to use the known propagation speed of ultrasonic waves in the air to measure the time when the sound wave encounters obstacles and reflect back after transmission, and calculate the actual distance from the transmitting point to the obstacle based on the time difference between transmission and reception. It can be seen that the principle of ultrasonic ranging sensor is the same as that of radar.
The formula of ultrasonic distance sensor is expressed as: L=C×T. where L is the measured distance length; C is the propagation speed of ultrasonic waves in the air; T is the time difference of the measuring distance propagation (T is half the value of the time from transmission to reception).
Ultrasonic distance sensors module is mainly used for distance measurement in reversing reminders, construction sites, industrial sites, etc. Although the current distance measurement range can reach 100 meters, the accuracy of measurement can only reach the order of centimeters. Due to the advantages of easy directional emission, good directivity, easy control of intensity, and no direct contact with the object being measured, ultrasonic waves are an ideal method for liquid height measurement. It is necessary to achieve millimeter-level measurement accuracy in precise liquid level measurement, but the current domestic ultrasonic ranging special integrated circuits are only centimeter-level measurement accuracy. By analyzing the causes of the ultrasonic ranging error, improving the measurement time difference to the microsecond level, and using the LM92 temperature sensor to compensate the sound wave propagation velocity, the high-precision ultrasonic range finder we designed can achieve millimeter-level measurement accuracy.