RU64408U1 - DEVICE FOR DETECTING MOVING OBJECTS - Google Patents

Abstract

The utility model relates to electrical devices designed to detect penetration into a protected space of an enclosed space and generate an alert notification. The objective of this utility model is to achieve high noise immunity and reliability of detection devices in the protected area of moving objects. The problem is solved by a device for detecting moving objects, containing a pyroelectric radiation receiver with a digital output, an optoelectronic relay, the output circuit of which is connected to a loop relay, an LED indicator of device operability control and protection elements (filtering capacitors and varistors), characterized in that the device additionally contains a digital microcontroller as a logical device connected to a pyroelectric receiver for receiving data from it and controlling Abot indicator and loop relay.

Description

The utility model relates to electrical devices designed to detect penetration into a protected space of an enclosed space and generate an alert notification.

A known method of adaptive detection of objects and a device for its implementation (1), comprising an input unit, an optical unit, a spectral filtering unit, an operation unit, and an associated emitter located along the path of optical radiation, a radiation transmission unit, and a sensor unit characterized in that it was additionally introduced a second radiator oriented electrically connected to the operating unit, oriented to the optical unit, oriented to the central region of the input unit — the third emitter and mechanically with A drive unit connected to the optical unit electrically connected to the operation unit, to which the input unit is also electrically connected, and a spectral filtering unit located between the radiation transmission unit and the sensor unit is connected to the operation unit. In this case, the first emitter, radiation transmission unit, spectral filtering unit and sensor unit are combined into a single semiconductor structure. However, the described device is quite difficult to manufacture and does not have a high degree of noise immunity.

The objective of this utility model is to achieve high noise immunity and reliability of detection devices in the protected area of moving objects.

The problem is solved by a device for detecting moving objects, containing a pyroelectric radiation receiver with a digital output, an optoelectronic relay, the output circuit of which is connected to a loop relay, an LED indicator of device operability control and protection elements (filtering capacitors and varistors), characterized in that the device additionally contains a digital microcontroller as a logical device connected to a pyroelectric receiver for receiving data from it and controlling Abot indicator and loop relay.

The device issues the following types of notifications:

- “Norma” is formed by the device during the entire time of protection by closed relay contacts and off indicator when there is no human movement in the detection zone.

- “Alarm” is generated by the device by opening the relay contacts and turning on the indicator for a period of 5 s when a movement of a person (s) is detected in the detection zone.

The principle of operation of the device is based on recording changes in the flow of thermal radiation that occur when a person crosses sensitive areas. The sensitive areas of the device are formed by a Fresnel lens and a two-site digital pyroelectric radiation detector.

The electrical signal from the digital pyroelectric receiver is fed to the electronic circuit of the device.

In the electronic circuit, the received signal is processed and, based on the result, a decision is made on the formation of the “Normal” or “Alarm” modes.

The device operation diagram is shown in Fig. 1. The device operates as follows.

1. The RA2 line receives a 15-bit packet from the PYD-1998 digital pyroelectric receiver. In this case, the start bit is determined, and then the entire packet is received bit by bit with the required line timing. After receiving the packet, the microcontroller on the RA2 line sets a low level.

2. The received 15 bit packet is stored in a temporary variable.

3. Then, another packet is received from the pyroelectric receiver with the complete sequence of actions p1 and p2.

4. A mask is applied to the received packets (thus, the noise bits are removed).

5. We get the absolute value of the difference between the samples.

6. We measure the temperature at the RAO pin. Temperature is measured by measuring voltage from a divider formed by a constant resistor and a thermistor. This microcontroller input acts as an analog input. The voltage level is measured by the built-in analog-to-digital converter of the approximate type (ADC).

7. Based on the obtained value, we make a temperature correction of the sensitivity level of the device and store this value in a temporary variable.

8. We compare the obtained absolute value between two samples and the obtained sensitivity value.

9. If the absolute value obtained has exceeded the value of the sensitivity threshold, the "Alarm" mode is activated.

10. Otherwise, the “Normal” mode is confirmed.

Thus, the microcontroller DD1 acts as a master device - it receives data from the pyroelectric receiver DA2, processes the result, controls the operation of the indicator and the loop relay.

The devices are powered through a stabilized voltage source DA1.

The device is designed for continuous round-the-clock operation and has a temperature compensation function.

The applied solution allows to achieve high noise immunity, significantly reduce the number of components used on the printed circuit board, increase the reliability of the product, and make it easy to modify the finished device without changing the circuitry.

References:

1. Application for patent of the Russian Federation No. 96122141, 1999

Claims (1)

A moving object detection device comprising a pyroelectric radiation receiver with a digital output, an optoelectronic relay, the output circuit of which is connected to a loop relay, an LED device health monitoring indicator and protection elements (filtering capacitors and varistors), characterized in that it additionally contains a digital microcontroller as a logic devices connected to a pyroelectric receiver for receiving data from it and controlling the operation of the indicator and loop relay.