With the continuous development of science and technology, laser ranging, microwave radar ranging, ultrasonic ranging and infrared ranging have appeared in the field of ranging. As a measurement method with wide application and high measurement accuracy, infrared ranging uses the characteristics of non-diffusion and small refractive index when transmitting infrared rays, and is used according to the time required for infrared rays to be emitted from the transmitting module to be reflected by the object and accepted by the receiving module. The corresponding ranging formula is used to measure the distance of the object.
Infrared ranging sensor has several features, long-distance measurement, can measure long distance without reflector and low reflectivity; synchronous input, multiple sensors can be measured synchronously; wide measurement range, response Short time; compact design, easy to install, easy to operate; so its application value is relatively high.
The basic principle of the reflected energy method is that the infrared light emitting diode of the infrared emitting circuit emits infrared light, and after being reflected by the obstacle, the photosensitive receiving tube of the infrared receiving circuit receives the reflected light of the front object, thereby judging whether there is an obstacle in front. According to the intensity of the emitted light, the distance of the object can be judged. Since the intensity of the light received by the receiving tube changes with the distance of the reflected object, the reflected light is strong when the distance is close, and the reflected light is weak when the distance is long.
Because infrared is an electromagnetic wave between visible light and microwave, it not only has the characteristics of visible light transmission, reflection, refraction, but also some characteristics of microwave, such as strong penetration ability and can penetrate some Opaque substances, etc. The infrared sensor includes an infrared emitting device and an infrared receiving device. All objects in nature emit infrared light as long as the temperature is above absolute zero. Therefore, infrared sensors must have stronger transmitting and receiving capabilities.