RU2130201C1 - Security alarm device - Google Patents

Abstract

FIELD: security and fire protection equipment. SUBSTANCE: Goal of invention is achieved by introduced second signal continuity selector, relative pulse duration generator, electronic gate, second integrator and second threshold gate. Device provides possibility to separate fire detection function in order to generate Fire signal sent through separate communication line and to turn on built-in illumination indicator. EFFECT: increased reliability of operations. 3 cl, 3 dwg

Description

 The invention relates to techniques for security and fire alarms.

 A known ultrasonic device for alarm [1], containing a series-connected transceiver, integrator and shaper of the alarm. The transceiver consists of a radiating transducer connected to a generator, a receiving transducer connected to an ultrasonic frequency amplifier, the output of which is connected to a low-frequency amplifier through a Doppler signal detector, the output of which is the output of a transceiver.

The device [1] is a volumetric ultrasonic detector for detecting a moving intruder or fire. The principle of its operation is based on the Doppler effect, according to which the frequency of ultrasonic waves reflected from a moving object differs from the frequency of emitted waves by ± Δf _d , directly proportional to the radial velocity of the object (reflector) with respect to the emitter V _о , radiation frequency f _and and inversely proportional to the speed of propagation of ultrasound in a controlled environment C.

 The “+” sign corresponds to the movement of the reflector towards the device, the “-” sign - to the movement from it.

 The disadvantage of this device is the low noise immunity, reducing the reliability of its operation.

 This disadvantage is partially eliminated in the prototype device [2], the functional diagram of which is shown in FIG. 1.

 The device [2] contains a transceiver 1, a phase pulse selector 2, a continuity selector 3, a switch 4, an adder 5, an integrator 6, a threshold unit 7, an alarm driver 8, an OR element 9, an integrator 10, a threshold unit 11, an ultrasound receiver 12 , an ultrasound transmitter 13, a first detector 14, a phase shifter 15, a second detector 16, a first amplifier 17, a second amplifier 18.

 The outputs of the transceiver 1 are connected to the inputs of the phase pulse selector 2, the first and second outputs of which are connected to the first and second inputs of the switch 4 and to the inputs of the continuity selector signal 3, the output of which is connected to the third input of the switch 4, the outputs of which are connected to the inputs of the adder 5, the output which is connected through an integrator 6 and a threshold unit 7 to the input of the alarm generating unit 8.

In the prototype device [2], to increase noise immunity, quadrature signal processing is used. At the outputs of the phase pulse selector 2, rectangular pulse packets of a Doppler frequency signal are formed. Moreover, at the first output of the phase selector 2, these pulses appear when the reflector moves in the direction from the device, which corresponds to the negative sign of the Doppler frequency shift (-Δf _d ). At the second output of the phase selector 2, signal pulses appear corresponding to the positive sign of the Doppler frequency shift (+ Δf _d ). Such a shift occurs when the reflector moves towards the detector.

 Real reflectors form a Doppler signal having a wide energy spectrum (Fig. 2). However, for a moving person, he is mainly on one side of the semiaxis of the Doppler frequencies (positive or negative). Such a signal, accumulating in the integrator 6, leads to a change in the voltage for its output over a specified period of time, which goes beyond one of two thresholds (positive or negative) of the threshold block 7. For the Doppler signal arising from the reflection of ultrasonic waves from turbulent air flows (from radiators or drafts) moving under the action of curtains or leaves of indoor plants, a practically symmetrical form of the energy spectrum is characteristic. Adding up to the adder 5 with different signs (subtracting), the signal energy in this case is insufficient to change the voltage at the output of the integrator 6 to the voltage value of the threshold block 7.

 The spectrum of the signal from the fire source always has a pronounced positive shift along the axis of the Doppler frequencies (due to the relative position of the device and the direction of movement of the hot gas flows), as well as a significant width associated with flame pulsation and intense turbulence of heat flows. As a result, at the output of the integrator 6, the voltage "with difficulty" overcomes the upper (positive) threshold of block 7.

 In the prototype device [2] an alarm is generated regardless of the source of the Doppler signal - a moving intruder or a fire. This is a significant drawback not only of the device [2], but of all currently existing ultrasonic detectors [3], therefore, they cannot be used in fire alarm systems at objects at a time when people are present there. In this case, they will respond to a moving person and periodically generate alarms, which is unacceptable. At the same time, there is a mandatory requirement for fire alarm systems about round-the-clock monitoring of the fire situation at the facility [4].

 In addition, the practical operation of detectors with quadrature signal processing and, in particular, a detector manufactured using the invention [2], showed that they have significantly reduced sensitivity to detection of a fire source and guarantee detection of a fire source is possible only in case of special installation of the detector ( for example, on the ceiling) [5].

 These disadvantages reduce the reliability of the operation of the device [2].

 The task of the claimed device is to increase the reliability of its operation, achieved by highlighting the detection function of the fire.

The problem is solved in that in the known device [2] containing a transceiver, the outputs of which are connected to the inputs of the phase pulse selector, the first and second outputs of which are connected to the first and second inputs of the switch and to the inputs of the first signal continuity selector, the output of which is connected to the third the input of the switch, the outputs of which are connected to the corresponding inputs of the adder, the output of which through the integrator and the first threshold block is connected to the first input of the notification unit, the second signal continuity selector, duty cycle driver, electronic key, second integrator and second threshold block. The second output of the phase pulse selector for outputting a signal with a positive shift of Doppler frequencies + Δf _d is connected to the input of the second signal continuity selector and the input of the duty cycle former, the output of which is connected to the first input of the electronic key. The output of the second signal continuity selector is connected to the second input of the electronic key, the output of which is connected through the second integrator and the second threshold block in series to the second input of the notification unit. The output of the first pulse selector is connected to the third input of the alarm notification generation unit.

 The second signal continuity selector comprises an integrator and a threshold block connected in series, wherein the integrator input is the input of the second signal continuity selector, and the output of the threshold block is the output of the second signal continuity selector.

 The notification generation unit comprises a first “Alarm” signal conditioner, a second light indication signal conditioner, a third “Fire” signal conditioner, and three light indicators.

 The first input of the notification unit is the input of the first “Alarm” signal conditioner, the first output of which is connected to the first input of the second light signal conditioner, and the second output is used to transmit an alarm notification to the communication line. The second input of the notification unit is the input of the third “Fire” signal shaper, the first output of which is connected to the second input of the second light indication signal shaper, and the second output is used to transmit the fire notification to the communication line. The third input of the notification generation unit is the third input of the second light driver, the outputs of which are connected to the corresponding light indicators.

 In the inventive device, all known blocks can be identical to the prototype device [2]. All introduced new blocks can be performed according to standard schemes given in [6, 7].

 In FIG. 2 shows a diagram of the inventive device for alarm.

 The device comprises a transceiver 1, a phase selector for pulses 2, a first signal continuity selector 3, a second signal continuity selector 4, a duty cycle shaper 5, a switch 6, an electronic key 7, an adder 8, a first integrator 9, a second integrator 10, a first threshold block 11, notification generation unit 12, second threshold unit 13, integrator 14, threshold unit 15, first “Alarm” signal conditioner 16, second light indication signal conditioner 17, third “Fire” signal conditioner 18, light indicators 19, 20, 21.

The outputs of the transceiver 1 are connected to the inputs of the phase pulse selector 2, the first and second outputs of which are connected to the first and second inputs of the switch 6 and to the inputs of the first continuity selector signal 3, the output of which is connected to the third input of the notification unit 12 and to the third input of the switch 6, the outputs of which are connected to the corresponding inputs of the adder 8, the output of which through the integrator 9 and the first threshold unit 11 is connected to the first input of the notification unit 12. The second output of the impu sov 2 for outputting a signal with a positive Doppler shift of + Δf _d connected to the input of the second selector continuity signal 4 and an input of the duty cycle 5, the output of which is connected to the first input of the electronic key. The output of the second signal continuity selector 4 is connected to the second input of the electronic key 7, the output of which is connected through the second integrator 10 and the second threshold unit 13 in series to the second input of the notification unit 12.

 The second continuity selector of signal 4 contains sequentially connected integrator 14 and threshold block 15, while the input of the integrator 14 is the input of the continuity selector of signal 4, and the output of the integrator 14 is the output of the continuity selector of signal 4.

 The notification generation unit 12 comprises a first “Alarm” signal conditioner 16, a second light indication signal conditioner 17, a third “Fire” signal conditioner 18 and three light indicators 19, 20, 21.

 The first input of the notification unit 12 is the input of the first alarm driver 16, the first output of which is connected to the first input of the second light driver 17, and the second output is used to transmit an alarm notification to the communication line. The second input of the notification unit 12 is the input of the third “Fire” signal conditioner 18, the first output of which is connected to the second input of the second light indication signal generator 17, and the second output is used to transmit the fire notification to the communication line. The third input of the notification unit 12 is the third input of the second signal shaper of the light indication 17, the outputs of which are connected to the corresponding light indicators 19-21.

 The device operates as follows.

 After turning on the power, the transceiver located in the device’s case starts to emit a continuous ultrasonic frequency signal into the surrounding space. Ultrasonic waves reflected from stationary objects return to the transceiver, where they are converted into electrical signals, amplified and detected. In the absence of moving reflectors, there is no signal at the outputs of the transceiver corresponding to the Doppler frequency shift, therefore, the notification generation unit 12 generates a Norm message, in which a notification about the normal state of the object is transmitted through the communication lines, the light indicators 19-21 do not light.

When a moving person appears in the detection zone, the ultrasound waves reflected from it will have a Doppler frequency shift. At the same time, amplified low-frequency oscillations with a Doppler shift frequency of ± Δf _d having a phase shift angle of ± π / 2 relative to each other appear at the first and second outputs of the transceiver 1. The sign of the phase shift depends on the direction of movement of the person (reflector).

The signals from the outputs of the transceiver 1 enter the phase pulse selector 2, in which the signals are separated depending on the direction of movement of the reflector (the sign of the Doppler frequency Δf _l ) based on their relative phase shift and the selection of signals at the corresponding output of the selector 2. When the person moves from the detector (-Δf _d ) the signal appears at the first output of selector 2 and goes to the first input of switch 6 and the first input of the first selector of continuity of signal 3. When the reflector moves to the detector (+ Δf _d ) cash appears on the second output of the selector 2 and enters the second input of the switch 6, as well as the inputs of the second continuity selector signal 4 and the duty cycle 5.

 After the appearance of a signal at any of the inputs of the first continuity selector 3, a constant control voltage appears at its output and is supplied to the third input of the switch 6 and the third input of the shaper 12 of the notifications. In this case, with the help of the second driver 17 of the light indication signals, the “Noise” indicator light 20 is turned on, and the switch 6 is also opened for the passage of signals arriving at its first or second input. After passing the signals through the switch 6 and the adder 8, they accumulate in the integrator 9 with the polarity relative to the average value of the supply voltage corresponding to the sign of the Doppler frequency. When the voltage value at the output of the integrator 9 of one of the two symmetrically located (relative to the middle of the supply voltage) thresholds of the threshold block 11 is reached, it is triggered, and a signal arriving at the first input of the notification generator 12 appears on its output. Using the first shaper 16 signal "Alarm" in the communication line to the central monitoring station or control panel is transmitted alarm notification. At the same time, the control signal from the output of the first shaper 16 is fed to the input of the second shaper 17, which includes the "Alarm" indicator light.

 The Doppler signal from the second output of the phase selector 2 when a person moves in the detection zone also passes through the duty cycle driver 6 to the first input of the normally closed electronic key 7. At the same time, the Doppler signal from the second output of the selector 2 is fed to the input of the integrator 14 of the second signal continuity selector 4. The accumulator time of the integrator 14 before the triggering of the threshold block 15 is much longer than its discharge. The output of the threshold block 15 is connected to the second input of the electronic key 7. When the threshold block 15 is activated, the electronic key 7 is opened for the signal to pass to the integrator 10. The signal when a person moves in the detection zone is intermittent for a set time. With a decrease in the voltage at the output of the integrator 14, caused by a violation of the continuity of the signal, the control voltage at the output of the threshold block disappears, which leads to a fast (forced) discharge of the integrator 10. The set accumulation time of the integrator 10 before the threshold block 13 is activated is determined by the ratio of the maximum range of the device to the radial the speed of a person in the detection zone, that is, the possible time of the presence of a continuous signal from a person during his movement to the device. With a minimum detectable speed of 0.3 m / s, standardized by the standard [8], and real values of the maximum range for existing ultrasonic detectors of 6-8 m, it is 20-30 s. In addition, with real human movement, a violation of the signal continuity will be caused not only by its stops, but also by a change in direction of movement. The duty cycle driver 5 reduces the pulse duration of the Doppler signal while reducing its frequency. This leads to an increase in the duty cycle of the pulses entering the integrator 10 during a slow movement of a person, and, as a result, to an increase in the accumulation time of the integrator 10. This leads to an additional increase in the noise immunity of the fire detection channel.

 If the parameters of the integrator 10 and the second signal continuity selector are set in this way, a person’s movement in the detection zone cannot cause an increase in the voltage at the integrator’s output to the threshold of the threshold unit 13. Therefore, the “Fire” notification is not generated.

 When a fire selector appears in the detection zone of the fire at the second output of the phase selector 2, a continuous Doppler signal appears, caused by the reflection of ultrasonic waves from the ascending heat fluxes that arise in the immediate vicinity of the burning material. The signal intensity is not affected by the presence or absence of smoke due to the small size of its particles in comparison with the wavelength of the incident ultrasound.

 The Doppler signal is accumulated on the integrator 14, which causes the threshold block 15 to open the electronic key 7. The Doppler signal has a relatively high frequency, so it passes the duty cycle driver 5 with almost no distortion and enters the second integrator 10 through the electronic key 7.

 After the set delay time, the voltage at the integrator 10 reaches the threshold of the second threshold unit 13, the output of which is a signal fed to the second input of the notification unit 12 - the input of the third driver 18 of the "Fire" signal. As a result, a fire notification is transmitted from the output of the shaper 18 to the communication line, and with the help of the second shaper 17 of the light indication signals, the light indicator 21 is turned on.

 When a fire occurs in the detection zone, the Doppler signal from the outputs of the phase selector 2 also arrives at the inputs of the switch 6 and the first signal continuity selector 3. This leads to the appearance of a control signal at the output of the first selector 3, which opens the switch 6 and calls it using the second driver 17 inclusion of the indicator light "Noise". The energy components of the signals with a positive and negative Doppler frequency shift come from the outputs of the switch 6 through the adder 8 to the integrator 9 and are subtracted in it. The resulting component of the energy causes a voltage change on the integrator 9, which goes beyond the set threshold of the threshold unit 11, which leads to the formation of an alarm notification by the first driver 16 in the communication line, as well as the inclusion of the indicator light 19.

 Consequently, the appearance of a fire source can lead to the formation of not only a “Fire” notification, but also an “Alarm” notification, which increases the reliability of a device detecting a fire at an object. However, since the integrator 9 accumulates an energetically attenuated signal as a result of subtracting its components, the sensitivity of the fire detection channel is higher than the alarm channel.

 Thus, in the inventive device, the detection of the source of the fire when it occurs and the formation of a separate notice "Fire" in the communication line, as well as the inclusion of a special indicator light. When using such a device, regardless of the operation mode of the facility and the presence of people, control of a fire hazard situation at the facility can be ensured. In addition, in the absence of people at the facility, the device can carry out security functions and signal the unauthorized penetration of the intruder into the detection zone via a separate communication line, as well as by turning on a special light indicator. When a Doppler signal of sufficient level appears, the "Noise" indicator light is turned on, which can be used when installing and setting up the device on the protected object.

 In the process of development, an experimental model of the Echo-2P detector was made, in which the inventive device for alarming was used. He successfully passed tests at a real facility. Currently, a set of technical documentation is being prepared for transfer to the manufacturer.

Sources of information
1. Pat. 3885234 (USA), 1975, NKI 340-258.

 2. A.S. 1254917 (USSR), 1984, MKI G 08 B 13/16.

 3. Tkachevskaya M. Ya., Chlenov AN Ultrasonic Fire Alarm Detectors: Overview. - M .: GIC, 1986, - 56 p.

 4. SNiP 2.04.09-84 Fire automation of buildings and structures.

 5. Members A.N. The use of ultrasonic volumetric detectors in fire alarm systems // Materials of the scientific-practical conference "Actual problems of the prevention and suppression of fires at objects and in settlements". Moscow. 1996, - p. 65-67.

 6. Stepanenko I.P. Fundamentals of the theory of transistors and transistor circuits. - M.: Energy, 1973.- 608 p.

 7. Shkritek P. Reference manual for sound circuitry, trans. with him. -M. - World, 1991 .-- 446 p.

 8. GOST R50658-94. Alarm systems. Part 2. Requirements for alarm systems. Section 4. Ultrasonic detectors for enclosed spaces.

Claims (3)

1. The device for alarm, containing a transceiver, the outputs of which are connected to the inputs of the phase pulse selector, the first and second outputs of which are connected to the first and second inputs of the switch and the inputs of the first selector signal continuity, the output of which is connected to the third input of the switch, the outputs of which are connected to the corresponding inputs of the adder, the output of which through the integrator and the first threshold unit is connected to the first input of the notification unit, characterized in that the input swarm signal continuity selector, duty cycle driver, electronic switch, second integrator and second threshold block, second output of a phase pulse selector for outputting a signal with a positive Doppler frequency shift + Δf _d connected to the input of the second signal continuity selector and the input of duty cycle driver, the output of which is connected to the first input of the electronic key, the output of the second signal continuity selector is connected to the second input of the electronic key, the output of which is through the second egrator and a second threshold unit connected to the second input unit for generating notification, first continuity selector output signal is connected to a third input unit for generating notification.  2. The device according to claim 1, characterized in that the second signal continuity selector comprises an integrator and a threshold block connected in series, wherein the integrator input is the input of the second signal continuity selector, and the output of the threshold block is the output of the second signal continuity selector.  3. The device according to claim 1, characterized in that the notification unit includes a first signal driver “Alarm”, a second driver of light indication signals, a third driver of a signal “Fire” and three light indicators, the first input of the notification unit being the input of the first signal generator "Alarm", the first output of which is connected to the first input of the second signal driver of the light indication, and the second output is designed to transmit an alarm notification to the communication line, the second input of the block of notifications is the input of the third “Fire” signal conditioner, the first output of which is connected to the second input of the second light-signal conditioner, and the second output is used to transmit the fire notification to the communication line, the third input of the notification unit is the third input of the second light-signal conditioner the outputs of which are connected to the corresponding light indicators.

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