The popularization of smart homes and the use of human body sensing sensors in smart homes have enabled many families to use "high-tech" devices, making our lives more convenient and comfortable. In home life, various "smart devices" are always developed and changed around people. In order to achieve more intelligent effects, more and more sensors are being applied to smart life. Among them, the human body sensing sensor is a very important type.
There are three main ways for human induction: infrared pyroelectric induction, PCR radar sensor induction, and Doppler microwave induction.
1、 Infrared pyroelectric induction
A pyroelectric sensor is a type of sensor that can detect infrared radiation emitted by humans or animals. It utilizes the spontaneous polarization intensity of pyroelectric materials to generate charge movement with changes in external temperature. It detects changes in infrared energy emitted by the human body in a non-contact manner, converts it into electrical signals, and achieves sensing purposes.
Pyroelectric sensor is the most common human body sensing technology based on infrared detection. It exists in familiar products such as induction lamp, welcome device, intrusion alarm, and safety reminder at the entrance and exit of escalator.
2、 PCR radar sensor sensing
The Doppler radar sensing principle is adopted. By transmitting a 5.8GHz radar signal, once a moving object enters the sensing range, the radar signal waveform will be changed, thus triggering the action of the radar sensor.
Features: It can penetrate the plastic shell for concealed installation and is relatively beautiful. It can detect the human body in motion, as well as those who are still or asleep.
3、 Doppler microwave induction
The common frequency bands of Doppler microwave induction radar are 5.8GHz, 10GHz, and 24GHz; The principle is based on the Doppler principle. If a moving object enters the sensing range, it will change the waveform of the radar signal, thereby triggering the action of the radar sensor; Sensing people can penetrate plastic concealed installation, making it more aesthetically pleasing.
Advantages: It only senses people in motion and can penetrate the plastic hidden installation, making it more aesthetically pleasing. Disadvantage: Unable to sense people who are sitting still or sleeping.
The development of human body sensors has become very mature, but as smart home scenarios become more diverse, consumers have also put forward more diverse demands for high-precision human body sensors. This requires us to match different human body sensing technologies to meet consumer needs when designing smart home products, as there is no best product, only the best solution.