CN118522113A - Polarization-based smoke detection device and method - Google Patents

Abstract

The present invention discloses a smoke detection device and method based on polarization, and relates to the field of photoelectric detection technology. The device comprises: a detection system and a light blocking wall are arranged in a chamber; the detection system comprises a light emitting unit, a light receiving unit and a light blocking wall; the light blocking wall is arranged on the light emitting unit and the light receiving unit; the light blocking wall is used to prevent the light beam emitted by the light emitting unit from being directly received by the light receiving unit; the light emitting unit and the light receiving unit are both connected to a control unit; the control unit is used to control the light emitting unit to periodically emit polarized light beams of different wavelengths according to a preset rule, and control the light receiving unit to periodically receive scattered light after the light beam is scattered by smoke particles to be detected in the chamber according to the preset rule; a fire determination unit is connected to the light receiving unit; the fire determination unit is used to determine the detection result of the smoke particles to be detected according to the scattered light; the detection result is fire smoke or non-fire smoke. The present invention can improve the accuracy of fire alarm.

Description

A smoke detection device and method based on polarization

Technical Field

The present invention relates to the field of photoelectric detection technology, and in particular to a smoke detection device and method based on polarization.

Background Art

A general fire detector refers to a device that determines a fire by detecting the heat and smoke generated during a fire. The types of fire detectors are divided into heat-sensing fire detectors and smoke-sensing fire detectors. Heat-sensing fire detectors are divided into constant temperature fire detectors for determining a fire when the temperature around the fire detector rises to a predetermined temperature or higher, and differential fire detectors for determining a fire when the temperature rise rate exceeds a critical value. Smoke-sensing fire detectors are divided into ionization fire detectors for measuring changes in ion current values caused by smoke and photoelectric fire detectors for detecting light scattering caused by smoke particles. In recent years, photoelectric fire detectors have been increasingly used to quickly detect fires. The structure of a photoelectric fire detector is that when smoke enters the cavity of a photoelectric fire detector and light is scattered by the incoming smoke particles, the photoelectric fire detector detects the scattered light and issues a fire alarm, as shown in Figures 1 and 2. However, actual smoke is not only fire smoke, but also non-fire smoke in the form of fine particles such as cooking smoke, cigarette smoke, water vapor, and fine dust generated in daily life. In these cases, the photoelectric fire detector can also determine it as a fire and issue an alarm. Therefore, the problem of frequent non-fire alarms has arisen, and a polarization-based smoke detection device is urgently needed to improve the accuracy of fire alarms.

Summary of the invention

The object of the present invention is to provide a polarization-based smoke detection device and method, which can improve the accuracy of fire alarm.

To achieve the above object, the present invention provides the following solutions:

A polarization-based smoke detection device comprising a chamber, a detection system and a fire determination unit, the device also comprising a control unit;

The detection system is disposed in the chamber;

The detection system includes a light emitting unit, a light receiving unit and a light blocking wall;

The light blocking wall is arranged on the light emitting unit and the light receiving unit; the light blocking wall is used to prevent the light beam emitted by the light emitting unit from being directly received by the light receiving unit;

The light emitting unit and the light receiving unit are both connected to the control unit; the control unit is used to control the light emitting unit to periodically emit polarized light beams of different wavelengths according to a preset rule, and control the light receiving unit to periodically receive scattered light after the light beams are scattered by the smoke particles to be detected in the chamber according to the preset rule;

The fire determination unit is connected to the light receiving unit; the fire determination unit is used to determine the detection result of the smoke particles to be detected according to the scattered light; the detection result is fire smoke or non-fire smoke.

Optionally, the light emitting unit and the light receiving unit are arranged on the same plane.

Optionally, the light-emitting unit includes a plurality of light-emitting modules; the light-receiving unit includes a plurality of light-receiving modules; the wavelengths of the light beams emitted by the light-emitting modules are inconsistent; and the wavelengths of the scattered light received by the light-receiving modules are inconsistent.

Optionally, the light emitting module includes a first light emitting submodule and a second light emitting submodule; the first light emitting submodule emits a horizontally polarized light beam; and the second light emitting submodule emits a vertically polarized light beam.

Optionally, the wavelength band of the horizontally polarized light beam is 380nm~480nm.

Optionally, the wavelength band of the vertically polarized light beam is 850nm~950nm.

Optionally, the light emitting unit is an LED.

Optionally, the light receiving unit is a photodiode.

A polarization-based smoke detection method is applied to the above-mentioned polarization-based smoke detection device, and the method comprises:

A first light source with a first wavelength, a second light source with a first wavelength, a first light source with a second wavelength, and a second light source with a second wavelength are obtained to periodically irradiate a plurality of scattered lights received by a light receiving unit after the smoke particles to be detected are scattered according to a preset rule;

The detection result of the smoke particles to be detected is determined according to each of the scattered lights; the detection result is fire smoke or non-fire smoke.

Optionally, determining the detection result of the smoke particles to be detected according to each of the scattered lights specifically includes:

The detection result of the smoke particles to be detected is determined according to the values at the same position of the first scattering matrix and the second scattering matrix.

According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

The present invention utilizes the polarization characteristics of light to distinguish between fire smoke and non-fire-like smoke. From the perspective of wave optics, the polarization generated by light as an electromagnetic wave is analyzed. In this case, the light is analyzed as an electric field, so the light is generally in a state where only the electric field is considered, that is, light beams vibrating in various directions perpendicular to the propagation direction are mixed together. However, by using a specific filter, the light can be made to vibrate in a specific direction. Polarization can generally be divided into linear polarization, circular polarization, and elliptical polarization; the Stokes vector is used to describe the polarization characteristics, and the first scattering matrix and the second scattering matrix are obtained, thereby determining the detection result of the smoke particles to be detected, so that the present invention improves the accuracy of fire alarm.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG. 1 is a general photoelectric fire detector in the prior art.

FIG. 2 is a schematic diagram of a state in which a photoelectric fire detector operates when smoke particles are introduced into the photoelectric fire detector.

FIG. 3 is a schematic diagram of the structure of a polarization-based smoke detection device.

FIG. 4 is a schematic diagram showing the positional relationship between the light emitting unit and the light receiving unit.

Fig. 5 is a schematic diagram of the relationship between the light-emitting unit and the light-receiving unit of the present invention and the control unit; Fig. 5 (a) is a schematic diagram of the connection relationship between the light-emitting unit and the light-receiving unit of the present invention and the control unit; Fig. 5 (b) is a schematic diagram of the timing relationship of controlling the light-emitting unit and the light-receiving unit of the present invention.

FIG. 6 is a flow chart of a polarization-based smoke detection method.

Reference numerals:

Light emitting unit—10, light receiving unit—20, light blocking wall—30, chamber—110, detection system—120, control unit—130, fire measuring unit—140.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

The object of the present invention is to provide a polarization-based smoke detection device and method, aiming to improve the accuracy of fire alarm.

The purpose of the present disclosure is to provide a polarization-based smoke detection device and method, the function of which is to distinguish between fire smoke and non-fire smoke by utilizing the principle that smoke particles change the polarization scattering characteristics of light.

The apparatus includes: a cavity into which smoke is introduced, a detection system including a light emitting unit emitting a plurality of light beams of different wavelengths into the cavity and a light receiving unit receiving scattered light from a plurality of light sources, a control unit configured to control the operation of the detection system, and a fire determination unit configured to distinguish between fire smoke and non-fire-like smoke by detecting and analyzing light receiving signals received by the light receiving unit. In this case, horizontal polarization and vertical polarization are applied to the plurality of light sources of the light emitting unit and the light receiving unit.

The method includes: periodically controlling and turning on or off a light emitting unit configured to emit light beams having a plurality of different wavelengths into a cavity into which measurement target smoke is introduced, controlling a light receiving unit to receive light scattered by the measurement target smoke introduced into the cavity, and determining that the target smoke is any one of fire smoke and non-fire-like smoke by detecting and analyzing a light receiving signal received by the light receiving unit. In this case, horizontal polarization and vertical polarization are applied to a plurality of light sources of the light emitting unit and the light receiving unit. The above technical problem is solved by executing the method of detecting smoke based on polarization by combining a computer program with a computer as hardware, and the computer program is stored in a computer-readable recording medium.

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

Example 1

As shown in FIG. 3 , the polarization-based smoke detection device in this embodiment includes: a chamber 110 , a detection system 120 , a fire determination unit 140 and a control unit 130 .

The detection system 120 is disposed in the chamber 110 .

The detection system 120 includes a light emitting unit 10 , a light receiving unit 20 , and a light blocking wall 30 .

The light blocking wall 30 is disposed on the light emitting unit 10 and the light receiving unit 20 ; the light blocking wall 30 is used to prevent the light beam emitted by the light emitting unit 10 from being directly received by the light receiving unit 20 .

The light-emitting unit 10 and the light-receiving unit 20 are both connected to the control unit 130; the control unit 130 is used to control the light-emitting unit 10 to periodically emit polarized light beams of different wavelengths according to a preset rule, and to control the light-receiving unit 20 to periodically receive scattered light after the light beam is scattered by the smoke particles to be detected in the chamber 110 according to the preset rule.

The fire determination unit 140 is connected to the light receiving unit 20 ; the fire determination unit 140 is used to determine the detection result of the smoke particles to be detected according to the scattered light; the detection result is fire smoke or non-fire smoke.

Specifically, the light emitting unit 10 and the light receiving unit 20 are arranged on the same plane.

Furthermore, the light emitting unit 10 includes a plurality of light emitting modules; the light receiving unit 20 includes a plurality of light receiving modules; the wavelengths of the light beams emitted by the light emitting modules are inconsistent; and the wavelengths of the scattered light received by the light receiving modules are inconsistent.

Preferably, the light emitting module comprises a first light emitting submodule 10 - 1 and a second light emitting submodule 10 - 2 ; the first light emitting submodule 10 - 1 emits a horizontally polarized light beam; the second light emitting submodule 10 - 2 emits a vertically polarized light beam.

As a specific implementation, the wavelength band of the horizontal polarized light beam is 380nm-480nm. The wavelength band of the vertical polarized light beam is 850nm-950nm. The light emitting unit is an LED. The light receiving unit 20 is a photodiode.

In practical applications, as shown in FIG3 , the polarization-based smoke detection device includes: a chamber 110; a detection system 120 including a light emitting unit 10 and a light receiving unit 20; a control unit 130 and a fire determination unit 140. The chamber 110 has a smoke detection space into which smoke is introduced. The light emitting unit 10 emits light to the smoke detection space. The scattered light generated by the light being scattered by smoke particles is received by the light receiving unit 20. The detection system 120 includes the light emitting unit 10 and the light receiving unit 20. The light emitting unit 10 emits light beams having a plurality of different wavelengths to the space in the chamber 110. The light receiving unit 20 detects the scattered light generated when the light beams of the corresponding wavelengths are scattered by smoke particles. In this case, as shown in FIG3 , a partition wall is provided between the light emitting unit 10 and the light receiving unit 20 to prevent light leakage, that is, to prevent the light emitted from the light emitting unit 10 from being directly detected by the receiving unit 20. The control unit 130 controls the operation of the detection system 120. The fire determination unit 140 detects and analyzes the light receiving signal from the light receiving unit 20, and distinguishes between fire smoke and non-fire smoke. The fire determination unit 140 detects and analyzes the light receiving signal from the light receiving unit 20, and distinguishes between fire smoke and non-fire smoke.

4, the light emitting unit 10 may include a plurality of light sources configured to emit light beams having a plurality of different wavelengths. The light receiving unit 20 may include at least one photodiode configured to receive light beams having a plurality of wavelengths while distinguishing the plurality of wavelengths.

In one embodiment, the light-emitting unit 10 may include: a first light source 10-1, the first band is 380nm~480nm, and horizontal polarization is adopted (such as LED1// and LED2// in Figure 4, LED1// and LED2// in Figure 4 represent horizontally polarized light sources); a second light source 10-2, the second band is 850nm~950nm, and vertical polarization is adopted (such as LED1⊥ and LED2⊥ in Figure 4, LED1⊥ and LED2⊥ in Figure 4 represent vertically polarized light sources), and LED1 and LED2 in Figure 4 respectively represent two groups of light-emitting diodes in the same light source. In this case, the present invention does not limit the number of light sources and the specific values of the first band and the second band, and can be set according to performance factors. The light receiving unit 20 can be configured as a photodiode capable of receiving the first band and the second band corresponding to the above configuration. That is, the light receiving unit 20 may include a first photodiode 20-1 using horizontal polarization corresponding to the first light source and the second light source (PD// in FIG. 4 represents a photodiode using horizontal polarization) and a second photodiode 20-2 using the vertical polarization (PD⊥ in FIG. 4 represents a photodiode using vertical polarization). In the structure of the light emitting unit 10 and the light receiving unit 20 of the detection system 120, in order to minimize the difference in detection signals caused by the arrangement distance between the light emitting unit 10 using horizontal polarization and vertical polarization and the light receiving unit 20 using horizontal polarization and vertical polarization, the light emitting unit 10 and the light receiving unit 20 are arranged in a dot matrix structure. The first light source 10-1 is arranged in the upper left end area of the detection system, the first photodiode 20-1 is arranged in the lower end area based on the first light source 10-1, and the second photodiode 20-2 is arranged in the right area. In addition, the second light source 10-2 is arranged in a diagonal direction relative to the first light source 10-1. In this case, a partition wall or shielding structure is provided between the first light source 10-1 and the second light source 10-2 and between the first photodiode 20-1 and the second photodiode 20-2, and the partition wall or shielding structure is the light blocking wall 30 in the present invention. Considering that the light emitting unit 10 and the light receiving unit 20 are in a short distance configuration in the embodiment of the present invention, a partition wall or shielding structure is applied between the dot matrix arrangement to reduce the influence of light leaked from the light emitting unit without blocking the reflection of smoke particles.

FIG5 is a schematic diagram of the relationship between the light-emitting unit and the light-receiving unit and the control unit. LED1//, LED2//, LED1⊥ and LED2⊥ in FIG5 are consistent with those in FIG4 and are not described in detail here. I in FIG5 represents a received light signal, 1 in I1 corresponds to the first photodiode, 2 in I2 corresponds to the second photodiode, ∥∥ represents a signal received from a light source with horizontal polarization in horizontal polarization, ∥⊥ represents a signal received from a light source with horizontal polarization in vertical polarization, ⊥∥ represents a signal received from a light source with vertical polarization in horizontal polarization, and ⊥⊥ represents a signal received from a light source with vertical polarization in vertical polarization. As shown in FIG5(a) and FIG5(b), the control unit 130 can perform on/off control on the first light source 10-1 and the second light source 10-2 of the light-emitting unit emitting light with two wavelength bands. The control unit 130 can perform on/off control on the LED of the light-emitting unit, which includes a total of four light sources, namely, a first light source 10-1 and a second light source 10-2 using horizontal polarization and vertical polarization, and emits light of two wavelengths. The control unit 130 can be controlled so that the light-emitting time of the multiple first light sources 10-1 and the second light source 10-2 of the light-emitting unit 10 is different within a cycle to prevent interference between multiple wavelengths. For example, the first light source 10-1 and the second light source 10-2 can be turned on and off alternately according to the number of light emission times. As another example, a light source with vertical polarization and a light source with horizontal polarization can be turned on and off alternately. At the first light emission time, the LED using horizontal polarization with the first wavelength band of the first light source 10-1 is controlled on/off. Then, at the second light emission time, the LED using vertical polarization with the first wavelength band of the second light source 10-2 is controlled on/off. Next, at the third light emission time, the LED using horizontal polarization with the second wavelength band of the first light source 10-1 is controlled on/off. Then, at the fourth light emission time, the LED using vertical polarization having the second wavelength band of the second light source 10 - 2 is on/off controlled.

Further, on/off 1, on/off 2, on/off 3 and on/off 4 are turned on/off in sequence and cycled, respectively controlling the emission of parallel polarized light of the first light source, vertical polarized light of the first light source, parallel polarized light of the second light source and vertical polarized light of the second light source. Take the first vertical row in Figure 5 (b) as an example: when the horizontal polarization of the first light source is turned on, measurement 1 and measurement 2 can simultaneously measure the light received by the first light receiving unit and the second light receiving unit, that is, the horizontal polarized light and vertical polarized light received by the parallel polarized light emitted by the first light source after being reflected by the smoke particles. Sequentially, the second vertical row indicates that when the vertical polarization of the first light source is turned on, measurement 1 and measurement 2 can simultaneously measure the light received by the first light receiving unit and the second light receiving unit, that is, the horizontal polarized light and vertical polarized light received by the vertical polarized light emitted by the first light source after being reflected by the smoke particles; and so on, no further description is given.

When the LEDs of the first photodiode 20-1 and the second photodiode 20-2 using horizontal polarization and vertical polarization are turned on, the control unit 130 controls to detect the light reception signal. In this case, the control unit sets different light emission times within one cycle and sequentially controls the first light source 10-1 and the second light source 10-2 on/off at predetermined time intervals so that the first light source 10-1 and the second light source 10-2 do not interfere with each other.

The light receiving unit 20 detects a light receiving signal corresponding to the light emission time within the same cycle. For example, the first photodiode 20-1 of the light receiving unit 20 continuously detects the first light signal and the second light signal emitted by the first light source 10-1 and the second light source 10-2 having the first wavelength band, and the third and fourth light signals emitted by the first light source 10-1 and the second light source 10-2 having the second wavelength band. In addition, the second photodiode 20-2 continuously detects the first light receiving signal and the second light receiving signal received by the first light source 10-1 and the second light source 10-2 having the first wavelength band, and the third and fourth light receiving signals received by the first light source 10-1 and the second light source 10-2 having the second wavelength band.

The control unit 130 repeatedly controls the light emitting unit 10 and the light receiving unit 20, so that the light emitting unit 10 and the light receiving unit 20 controlled in one cycle operate as a fire detector. At the same time, for the scattered light detected by the control unit 130, the fire determination unit 140 can calculate a scattering matrix in response to the light receiving signal of the light receiving unit 20, and distinguish between fire smoke and non-fire-like smoke.

Specifically, a first photodiode with horizontal polarization corresponding to the first light source and the second light source is configured to simultaneously receive the first wavelength band and the second wavelength band; a second photodiode with vertical polarization corresponding to the first light source and the second light source is configured to simultaneously receive the first wavelength band and the second wavelength band. The first light source and the second light source of the light emitting unit and the first photodiode and the second photodiode are arranged in a lattice shape. A partition wall or a shielding structure is provided between the lattice arrangements.

Furthermore, the light emission time of the multiple first light sources and the second light sources of the light emitting unit in one cycle is made different to prevent interference between the multiple light sources. The control unit controls the first photodiode and the second photodiode of the light receiving unit to detect the light receiving signal corresponding to the light emission time. The control unit continuously controls and turns on the first light source with the first wavelength band, the first light source with the second wavelength band, the second light source with the first wavelength band, and the second light source with the second wavelength band according to the light emission time in one cycle, and the control unit detects the light receiving signal by continuously controlling the first photodiode and the second photodiode corresponding to the light emission time.

The control unit continuously controls the first photodiode and the second photodiode, the first photodiode continuously detects the first light receiving signal and the second light receiving signal received by the first light source and the second light source having the first band, and the third light receiving signal and the fourth light receiving signal received by the first light source and the second light source having the second band; the second photodiode continuously detects the first light receiving signal and the second light receiving signal received by the first light source and the second light source having the first band, and the third light receiving signal and the fourth light receiving signal received by the second light source having the second band.

Among the first light receiving signals to the fourth light receiving signals of the first photodiode and the second photodiode, the fire determination unit calculates a first scattering matrix in response to the light receiving signals, and calculates a second scattering matrix in response to the light receiving signals, and a second scattering matrix relative to the second wavelength band. The fire determination unit distinguishes between fire smoke and non-fire-like smoke based on a combination of scattering matrix values of the first scattering matrix and the second scattering matrix. The fire determination unit distinguishes between fire smoke and non-fire-like smoke based on a result of comparing scattering matrix values at the same position in the first scattering matrix and the second scattering matrix.

Through the above design scheme, the present invention can bring the following beneficial effects:

According to the subject matter of the present disclosure described above, the device and method for detecting smoke having the function of distinguishing between fire and non-fire can reduce false alarms caused by non-fire alarms caused by smoke generated in daily life.

Example 2

The present invention further provides a polarization-based smoke detection method, which is applied to the polarization-based smoke detection device in Example 1. The method comprises:

Step S1: obtain a first light source with a first wavelength, a second light source with a first wavelength, a first light source with a second wavelength and a second light source with a second wavelength, and periodically irradiate a plurality of scattered lights received by a light receiving unit after the smoke particles to be detected are scattered according to a preset rule.

Step S2: determining the detection result of the smoke particles to be detected according to each of the scattered lights; the detection result is fire smoke or non-fire smoke.

Furthermore, the detection result of the smoke particles to be detected is determined according to the values at the same position of the first scattering matrix and the second scattering matrix.

In practical applications, in order to solve the above problems, the present invention uses the polarization characteristics of light to distinguish between fire smoke and non-fire-like smoke. From the perspective of wave optics, the polarization generated by light as an electromagnetic wave refers to the phenomenon that the electric field or magnetic field constituting the electromagnetic wave vibrates in a specific direction when the electromagnetic wave propagates. In this case, since light can be analyzed as an electric field, the light is generally in a state where only the electric field is considered, that is, light beams vibrating in various directions perpendicular to the propagation direction are mixed together. However, by using a specific filter, the light can be made to vibrate in a specific direction. Polarization can generally be divided into linear polarization, circular polarization, and elliptical polarization. As shown in FIG3 , a polarization-based smoke detection device is used to measure the detection value of the scattering matrix in formula (4). Since light contains transverse waves, light propagating in the z-axis direction can be expressed as the x component and the y component . Where A and B represent the intensity of light in their respective directions, ω represents the oscillation frequency, t represents time, k represents frequency, and z represents position. Represents the phase difference between the two components. When A or B is 0, it is linear polarization (vertical or horizontal polarization). When A=B, φ=90° or φ=-90°, it is circular polarization (right-hand circular polarization or left-hand circular polarization). When A and B are not 0, A≠B, φ≠0, ±90°, it is elliptical polarization. The Stokes vector can be used to describe the polarization characteristics. The Stokes vector is expressed as formula (1). Where in represents the incident light and sc represents the scattered light.

(1)

I, Q, U and V represent the shape of polarization, represents the wavelength, Indicates the caliber, It represents the relationship between the polarization parameter of the i-th heat dissipation light and the polarization parameter of the j-th incident light. When i=1, 2, 3, 4, they correspond to I, Q, U and V respectively; when j=1, 2, 3, 4, they correspond to I, Q, U and V respectively. The polarization shapes are shown in Table 1.

Table 1 Polarization shape statistics

The present invention is characterized in that the horizontal polarization characteristic and the vertical polarization characteristic are used in the polarization characteristic of light. Therefore, since only I and Q exist in Table 1 and Formula 1, Formula (1) can be converted into the following Formula (2):

(2)

Equation (2) can be transformed into equation (3) again. Subscript 0 represents incident light, ∥ represents horizontal polarization, and ⊥ represents vertical polarization.

(3)

in, , ; , .

Therefore, assuming that the light source is constant, the scattering matrix elements of the Stokes vector shown in equation (4) can be obtained through the detection values of horizontal polarization and vertical polarization.

(4)

Equation (5) shows a scattering matrix calculated for scattered light detected by the control unit 130 in response to the light reception signal of the light receiving unit 20 .

(5)

In formula (5), I represents the received light signal, 1 in I1 and F1 corresponds to the first photodiode, 2 in I2 and F2 corresponds to the second photodiode, the signal is the measurement value of the light receiving unit 20, the subscript ∥ represents horizontal polarization, and ⊥ represents vertical polarization. In addition, in the continuous subscripts ∥∥, the first subscript ∥ represents the horizontal polarization emitted by the light source, and the second subscript ∥ represents the application of horizontal polarization to the light receiving unit 20. More specifically, ∥∥ represents a signal received from a light source with horizontal polarization in horizontal polarization, ∥⊥ represents a signal received from a light source with horizontal polarization in vertical polarization, ⊥∥ represents a signal received from a light source with vertical polarization in horizontal polarization, and ⊥⊥ represents a signal received from a light source with vertical polarization in vertical polarization.

The fire determination unit 140 calculates a first scattering matrix with respect to the light receiving signal of the first wavelength band among the first light receiving signal to the fourth light receiving signal in response to the first photodiode 20-1 and the second photodiode 20-2, and a second scattering matrix with respect to the light receiving signal of the second wavelength band. The fire determination unit 140 can distinguish between fire smoke and non-fire-like smoke based on a mathematical combination of scattering matrix values of the first scattering matrix and the second scattering matrix, for example:

or or Equal values.

The first scattering matrix and the second scattering matrix are shown in formula (5).

The fire determination unit 140 can distinguish fire smoke from non-fire smoke by comparing the values F1 ₁₁ and F2 ₁₁ at the same position of the first scattering matrix and the second scattering matrix. Meanwhile, the mathematical combination can be derived differently from the properties and sizes of smoke particles. The present invention is not limited to a specific mathematical combination.

More specifically, first, after a preset fire smoke experiment, according to the properties and sizes of the fire smoke particles, the first scattering matrix and the second scattering matrix are calculated according to the method formula in the invention. (or other selected mathematical combinations) values, periodically open or close the device, obtain multiple sets of data, establish a database, and smoke particles of different properties will calculate different ranges of values. The values that do not belong to the range of this set database are eliminated to exclude non-fire smoke.

As shown in FIG6 , first, the light emitting unit is periodically controlled and turned on or off to emit a plurality of light beams with different wavelengths (S110). Then, the light receiving unit is controlled to receive scattered light to measure the target smoke introduced into the chamber (S120). Then, the target smoke is determined to be fire smoke or non-fire smoke by detecting and analyzing the received light signal (S130). Meanwhile, in the above description, steps S110, S120, and S130 may be divided into additional steps or combined into fewer steps according to the embodiments of the present disclosure, some steps may be cancelled if necessary, and the order of the steps may be changed.

The application method of the polarization-based smoke detection device provided by the present invention is as follows:

S110, periodically controlling and turning on or off the light-emitting unit to emit a plurality of light beams with different wavelengths, specifically including periodically controlling and turning on or off a first light source with a first wavelength band of 380-480nm and horizontal polarization and a second light source with a second wavelength band of 850-950nm and vertical polarization.

Wherein, periodically controlling and turning on or off a light-emitting unit configured to emit light beams having a plurality of different wavelengths includes continuously controlling and turning on a first light source having a first wavelength band, a first light source having a second wavelength band, a second light source having a first wavelength band, and a second light source having a second wavelength band, and periodically emitting light according to the emission time within a cycle; and controlling a light-receiving unit to receive scattered light scattered by target smoke introduced into the chamber, includes controlling a first photodiode and a second photodiode of the light-receiving unit to detect a light-receiving signal corresponding to the number of emission times.

S120, controlling the light receiving unit to receive scattered light to measure the target smoke introduced into the chamber. Specifically, the light receiving unit acquires a received light signal, wherein the light receiving unit includes a first photodiode with horizontal polarization corresponding to the first light source and the second light source, and the photodiode is configured to simultaneously receive light of the first wavelength band and the second wavelength band; and a second photodiode with vertical polarization corresponding to the first light source and the second light source, and configured to simultaneously receive light of the first wavelength band and the second wavelength band. The first light source and the second light source of the light emitting unit and the first photodiode and the second photodiode are arranged in a dot matrix shape, and a partition wall or a shielding structure is provided between the dot matrix arrangement.

The light receiving unit is controlled to receive light scattered by smoke introduced into the measurement target, including a first photodiode continuously detecting a first light signal and a second light signal emitted by a first light source and a second light source having a first wavelength band, and a third light signal and a fourth light signal emitted by the first light source and the second light source having a second wavelength band. The first light signal and the second light signal emitted by the first light source and the second light source having a first wavelength band, and a third light signal and a fourth light signal emitted by the first light source and the second light source having a second wavelength band are continuously detected by a second photodiode.

S130, determining whether the target smoke is fire smoke or non-fire smoke by detecting and analyzing the received light signal. Specifically, the fire determination unit calculates a first scattering matrix of the light receiving signal of the first wavelength band in response to the first light receiving signal to the fourth light receiving signal of the first photodiode and the second photodiode, and a second scattering matrix of the light receiving signal of the second wavelength band. Fire smoke and non-fire smoke are distinguished according to the result of comparing the scattering matrix values at the same position in the first scattering matrix and the second scattering matrix.

The above-mentioned method of detecting smoke based on polarization of the embodiment of the present disclosure can be implemented as a program stored in a computer so as to be executed by combining with computer hardware. In order for the computer to read the program and execute the method implemented by the program, the program may include code encoded in a computer language such as C, C++, Java, Ruby, etc., or a machine language code readable by the processor (CPU) of the computer through the device interface of the computer. Such code may include functional codes associated with functions and similar defined functions necessary to execute the method, and may include control codes associated with the execution process necessary for the computer processor to execute the function according to a predetermined process. In addition, such code may also include code related to memory references, which involves whether additional information or media necessary for the computer processor to execute the function is referenced at any location (address number) in the internal or external memory of the computer. In addition, if the processor of the computer needs to communicate with any computer or server located at a remote location to perform the function, the code may further include communication-related codes on how to perform communication with the server and the communication module of any computer or server located at a remote location, as well as whether any information or media is sent and received during communication. The storage medium is, for example, but not limited to, a read-only memory (ROM), a random access memory (RAM), a compact disk ROM (CD-ROM), a magnetic tape, a floppy disk, an optical data storage device, etc. The program can be stored in various storage media on various servers accessible by the computer or in various storage media on the user's computer. In addition, the medium can be distributed to computer systems connected via a network, and the computer readable code can be stored on a distributed basis.

The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims (10)

1. A polarization-based smoke detection device comprising a chamber, a detection system and a fire detection unit, characterized in that the device further comprises a control unit;

the detection system is arranged in the cavity;

the detection system comprises a light emitting unit, a light receiving unit and a light blocking wall;

the light blocking wall is disposed on the light emitting unit and the light receiving unit; the light blocking wall is used for preventing the light beam emitted by the light emitting unit from being directly received by the light receiving unit;

the light emitting unit and the light receiving unit are connected with the control unit; the control unit is used for controlling the light emitting unit to periodically emit polarized light beams with different wavelengths according to a preset rule and controlling the light receiving unit to periodically receive scattered light of the polarized light beams after being scattered by smoke particles to be detected in the cavity according to the preset rule;

the fire measuring unit is connected with the light receiving unit; the fire disaster measuring unit is used for determining the detection result of the smoke particles to be detected according to the scattered light; the detection result is fire smoke or non-fire smoke.

2. The polarization-based smoke detection device of claim 1, wherein the light emitting unit and the light receiving unit are disposed on the same plane.

3. The polarization-based smoke detection device of claim 2, wherein the lighting unit comprises a plurality of lighting modules; the light receiving unit includes a plurality of light receiving modules; the wavelength of the light beam emitted by each light emitting module is inconsistent; the scattered light received by each light receiving module has a non-uniform wavelength.

4. A polarization-based smoke detection device according to claim 3, wherein the light emitting module comprises a first light emitting sub-module and a second light emitting sub-module; the first light emitting sub-module emits a horizontally polarized light beam; the second light emitting sub-module emits a vertically polarized light beam.

5. The polarization-based smoke detection device of claim 4, wherein the band of the horizontally polarized light beam is 380nm to 480nm.

6. The polarization-based smoke detection device of claim 4, wherein the wavelength band of the vertically polarized light beam is 850nm to 950nm.

7. The polarization-based smoke detection device of claim 1, wherein the light emitting unit is an LED.

8. The polarization-based smoke detection device of claim 1, wherein the light receiving unit is a photodiode.

9. A polarization-based smoke detection method, applied to a polarization-based smoke detection device according to any one of claims 1 to 8, the method comprising:

Acquiring a first light source with a first wavelength, a second light source with the first wavelength, the first light source with the second wavelength and the second light source with the second wavelength, and periodically irradiating a plurality of scattered lights received by a light receiving unit after scattering smoke particles to be detected according to a preset rule;

determining detection results of the smoke particles to be detected according to the scattered light; the detection result is fire smoke or non-fire smoke.

10. The polarization-based smoke detection method according to claim 9, wherein determining the detection result of the smoke particles to be detected based on each of the scattered light, specifically comprises:

and determining the detection result of the smoke particles to be detected according to the values at the same positions of the first scattering matrix and the second scattering matrix.