Views: 10 Author: Site Editor Publish Time: 2018-05-17 Origin: Site
 50Khz arduino ultrasonic sensor |  ultrasonic distance sensor |  200Khz ultrasonic sensor |
From the working principle of long range ultrasonic distance transducer, it can be seen that the factors are influencing the measurement result that is mainly included,it is the ultrasonic wave speed, the time is from launching to receiving, it is the distance of the obstacle,which is the working mode of the ultrasonic probe,it is the blind signal interference signal. Ultrasonic propagation velocity compensation is the temperature compensation method, the speed of 50Khz arduino ultrasonic sensor in the air will be affected by temperature, it is to reduce the time error and improve the timing accuracy, reducing the time is quantization error, the count frequency is built-in timer of the microcontroller is only half of the crystal frequency.Therefore,the quantification error of ranging time is large. The introduction of a dedicated timing counter for timing can greatly reduce the distance measurement.quantization error improves the accuracy of the ranging system.
Accurately determining the echo time is the pulsed ultrasonic 75Khz ultrasonic distance transducer which can be approximately expressed as an attenuated sine curve. The mathematical model is that since m and u are constant, the maximum value of ultrasonic echo is envelope by ultrasonic echo packet. The time of difference at the beginning of the line is a fixed value. Due to the maximum signal-to-noise ratio at the peak of the echo envelope, the measurement of ultrasonic distance measuring transducer is more accurate. The echo time can be measured indirectly by measuring the time at which the echo maximum occurs.
The automatic gain adjustment link is serially connected in the receiving loop. Since the amplitude of the ultrasonic distance sensor decays exponentially with the increasing of the propagation distance, the automatic gain adjustment (AGV) link is serially inserted in the ultrasonic receiving circuit to enlarge the circuit. The multiple increases exponentially with the increasing of the measuring distance, so that the amplitude of the received echo 200Khz ultrasonic sensor does not change greatly with the changing of the measuring distance.
