Digital passive infrared stationary human body detector and detection method thereof

Abstract

The invention discloses a digital passive infrared static human body detector which comprises an outer shell, a microcontroller and a PIR sensor and is characterized in that a Fresnel lens is arranged at the front end of the PIR sensor, a matched reflector is installed between the PIR sensor and the Fresnel lens, and the microcontroller is connected with a power source module, a drive motor and a detection switch. A detection method includes: a, background noise is learned, and a background noise sequence is formed; b, dynamic human body detection is carried out; c, delayed output is carried out; d, static detection is judged whether to be carried out or not; e, detection signals are acquired, and a detection signal sequence is formed; f, the digital mutual correlation calculation is carried out; and g, a static human body is judged whether to exist or not. According to the detector and the method, false assumption of a prior passive static human body detector and the defect that the human body under the static state can not be detected are abandoned and avoided, and the human body under the static state in a detection area can be effectively and accurately detected so that the static detection is achieved.

Description

technical field [0001] The present invention relates to a digital passive infrared static human body detector and its detection method, more specifically, to a digital passive infrared static human body detector and its detection method which adopts detection signal and background noise to carry out digital cross-correlation operation method. Background technique [0002] Human body detection plays a very important role in intrusion detection and energy-saving control of security monitoring. Common human body detection methods include active and active types such as ultrasonic detection and microwave detection, and passive and passive types such as passive infrared (PIR) pyroelectric detection. category. Ultrasonic and microwave human body detection is based on the Doppler effect, which can only detect moving human bodies. It is a dynamic human body detection technology and cannot detect static human bodies. At the same time, these two detection methods will produce a ce...

AI Technical Summary

Problems solved by technology

[0004] The main disadvantages of passive infrared human body detectors are: 1), the signal amplitude is small, and it is easily interfered by various heat sources and light sources; 2), it can only detect the moving human body, when the human body is still, the detector cannot detect the existence of the human body; 3 ), when the ambient temperature is close to the human body temperature, the detection sensitivity drops significantly, sometimes causing short-term failure; 4), the main detection movement direction of the passive infrared detector is the tangential movement direction, and the detection ability of objects moving in the radial direction is relatively poor

[0020] (1) Regardless of the movement mode, it is impossible to achieve true static human detection by using the same amplitude discrimination method as dynamic human detection;

[0021] (2) A variety of mechanical moving parts such as motors, reduction gears and crank connecting rods are required, and the failure rate is high;

[0022] (3) The power consumption is large, the moving parts are always in the working state during the detection, and the power consumption is high, especially when a high-power DC or AC motor is required;

[0023] (4), unable to overcome the dead zone problem between Fresnel lens partitions and partitions, commonly used Fresnel lenses can be divided into spherical lenses and cylindrical lenses

[0025] (5), the minimum rotation angle and the best rotation speed are not given;

[0026] (6) The signal processing of human body detection adopts analog technology, the circuit is complicated and the stability is poor

Images