This study explores the correlation between the modulated optical frequency and the detection distance

and aims to change the infrared modulation optical frequency by software to realize " one-click " intelligent adjustment of distance detection. Taking the continuous cycle rectangular pulse signal as an example

the second order narrowband band-pass amplifier circuit is used to amplify and filter the input signal

and the pulse signal of different frequency is automatically adjusted by the narrowband band-pass amplifier to affect the sensitivity of the sensor. Through the theoretical derivation

simulation design

experimental analysis

the results show that when the pulse am

plitude and duty cycle are set constant

changing frequency of pulse signal can realize adjustment of sensor sensitivity

so as to realize the adjustment of detecting distance. When f

<

f

0

the sensitivity of the sensor increases with the increase of f; when f = f

0

the sensitivity is the largest; when f > f

0

the sensitivity decreases with the increase of f. In the infrared photoelectric switch sensor

the application of this method achieves the purpose that using software to adjust the frequency so as to adjust measurement distance of sensor.