RU66086U1 - DEVICE FOR DETECTING A CONNECTED ACCESS THROUGH A DOOR OPENING OF SEVERAL PERSONS - Google Patents

Abstract

The utility model relates to techniques for controlling access to rooms with limited access. The detection device includes a magnetic antenna, a measuring generator, amplitude and frequency paths, and a microcontroller.

A magnetic antenna covering a doorway through which people pass, together with a measuring generator, creates a magnetic field. The perturbations of the magnetic field caused by the bodies of passing people are converted into electrical signals, processed in the frequency and amplitude paths, and fed to the microcontroller. Due to the various ratios of the signals of the frequency and amplitude paths to the human body and metal objects, it becomes possible to compensate for the negative effect of metal objects on the signal on the human body. According to the magnitude of the signal of the frequency path in the program executed by the microcontroller, the compensation correction is calculated and subtracted from the signal of the amplitude path.

The magnetic antenna is made of a coaxial cable of the type RK-75, which allows you to bend and lay it along the door threshold. The manufacture of a magnetic antenna from a cable of the RK-75 brand leads to a decrease in the quality factor of the antenna, however, does not lead to an increase in output noise.

Effect: reducing the likelihood of a false alarm when one person walking along his access card, in the case when he has large metal objects; the emergence of the ability to flexibly lay the magnetic antenna along the door sill. 1 ill.

Description

Technical field

The utility model relates to techniques for controlling access to rooms with limited access.

State of the art

A device is known [Panin V.V., Kudryavtsev O.B. The concept of "magnetic weight" of the human body and anti-piggybacking devices for access control systems created on its basis // Devices and Systems. Management, control, diagnostics, No. 4, 2002], having a magnetic antenna built into the door frame or doorway, an electronic unit of the magnetic antenna and a microcontroller. When two people pass through the doorway after presenting an access card belonging to one of these people to the reader, the microcontroller generates an alarm signal by comparing the measured total “magnetic weight” of two people with the base “magnetic weight” of the cardholder.

The disadvantage of this device is the increased likelihood of a false alarm when one person is walking on his access card, in the case when he has large metal objects.

An additional disadvantage of this device is the manufacture of a magnetic antenna from a hard microwave cable with a continuous outer sheath, which makes it impossible to flexibly lay the antenna along the door sill.

Utility Model Essence

We propose a device for detecting a single passage of several people through a doorway with a lockable door. The device includes a magnetic antenna, a measuring generator, amplitude and frequency paths, and a microcontroller.

A magnetic antenna covering a doorway through which people pass, together with a measuring generator, creates a magnetic field. The perturbations of the magnetic field caused by the bodies of passing people are converted into electrical signals, processed in the frequency and amplitude paths, and fed to the microcontroller. Due to the various ratios of the signals of the frequency and amplitude paths to the human body and metal objects, it becomes possible to compensate for the negative effect of metal objects on the signal on the human body. According to the magnitude of the signal of the frequency path in the program executed by the microcontroller, the compensation correction is calculated and subtracted from the signal of the amplitude path.

The magnetic antenna is made of a coaxial cable of the type RK-75, which allows you to bend and lay it along the door threshold. The manufacture of a magnetic antenna from a cable of the RK-75 brand leads to a decrease in the quality factor of the antenna, however, does not lead to an increase in output noise.

Brief Description of the Drawings

The essence of the utility model is illustrated by the drawing in figure 1, which shows a block diagram of a detection device installed on the doorway.

Information confirming the feasibility of implementing a utility model

The detection device contains a magnetic antenna (1) made of a coaxial cable of the RK-75 brand and mounted on the doorway (2). The antenna outputs are connected to a measuring generator (3), the output of which is connected to the inputs of the frequency (4) and amplitude (5) paths, the output signals of which are fed to

microcontroller (6). The signal is calculated in the microcontroller (6): where U _met , f _met - output signals of the amplitude and frequency paths to a metal object; U _Σ , f _Σ - output signals of the amplitude and frequency paths to the human body with a metal object. This signal U * is compared in the microcontroller (6) with a threshold value of U * _pores . If U * exceeds U * _{then an} alarm is generated.

Testing of the detection device was carried out by the passage of people through the doorway, carrying a case reinforced with a metal frame around the perimeter. The probability of a false alarm during the passage of one person walking on his access card was less than 0.01.

Claims (1)

A device for detecting a single passage through a doorway of several people, containing a magnetic antenna, a measuring generator, amplitude and frequency paths and a microcontroller, characterized in that the microcontroller implements an algorithm for compensating the negative effect of metal objects on the signal on the human body, while the magnetic antenna is flexibly laid along the door sill, made of coaxial cable of the RK-75 type.