A method and system for improving the anti-fouling performance of a smoke fire detector

Abstract

The application discloses a method and system for improving the anti-dust performance of a smoke fire detector, relates to the technical field of fire alarm, and solves the technical problem that the dust in the optical darkroom of the detector leads to the decrease of the alarm reliability of the detector, and the fire risk cannot be timely warned; the initialization state of the detector is adjusted to a high-sensitivity state, the smoke concentration is detected in a time mode, and the background value is updated, then the working state of the detector is adaptively adjusted according to the detection result and the background value of the detector, and finally, the fire is alarmed according to the smoke concentration; the influence of the dust in the optical darkroom of the detector on the working state of the photoelectric smoke fire detector is reduced, so that the cleaning cycle of the detector is prolonged, and the consumption of manpower and material resources is reduced.

Description

Technical Field

[0001] This invention belongs to the field of fire protection facilities and relates to fire alarm technology, specifically a method and system for improving the anti-ash accumulation performance of smoke detectors. Background Technology

[0002] In automatic fire alarm systems, photoelectric smoke detectors are the most widely used fire triggering devices. The key components of a photoelectric smoke detector are the light signal emitting tube and the light signal receiving tube installed in the optical dark chamber. When the air is relatively clean and there are few particles in the optical dark chamber, only a small amount of light reaches the receiving tube due to reflection from the inner wall of the dark chamber, generating a weak electrical signal. After conversion by the detector's electrical signal processing module, a small detection value is obtained. When the air is polluted, such as due to smoke from a fire caused by combustion, and there are more particles in the optical dark chamber, the light reaching the receiving tube increases significantly due to the scattering effect of the particles, generating a stronger electrical signal. After conversion by the detector's signal processing module, a larger detection value is obtained. The detection value collected by the detector in clean air is called the detector's background value, and the detection value collected by the detector at regular intervals is called the detector's real-time value. When the difference between the real-time value and the background value exceeds the alarm threshold, the detector generates a fire warning signal.

[0003] In existing photoelectric smoke detectors, dust gradually accumulates in the optical dark chamber after deployment, causing the detector's background value to increase. When the sum of the background value and the alarm threshold exceeds the detector's detection range, the detector will malfunction. Therefore, existing technologies pose a risk of reduced alarm reliability due to dust accumulation in the detector's optical dark chamber, resulting in delayed fire warnings.

[0004] This invention provides a method and system for improving the anti-ash accumulation performance of smoke detectors to solve the above-mentioned technical problems. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art; to this end, the present invention proposes a method and system for improving the anti-ash accumulation performance of smoke fire detectors, which is used to solve the technical problem that the detector alarm reliability is reduced due to ash accumulation in the optical dark chamber of the detector in the prior art, and that there is a lack of timely early warning of fire risks.

[0006] To achieve the above objectives, a first aspect of the present invention provides a method for improving the anti-ash accumulation performance of smoke detectors, comprising:

[0007] S1. Set the detector sensitivity adjustment threshold and fire alarm threshold; adjust the detector's initialization state to high sensitivity state;

[0008] S2. Initialize the detector background value; periodically detect the smoke concentration to obtain the detection value, and periodically update the detector background value;

[0009] S3. Obtain the working status of the detector and adaptively adjust the working status of the detector based on the detected value and the background value;

[0010] S4. Alarm the fire based on the smoke concentration detection value and the detector's background value.

[0011] Preferably, the setting of the detector sensitivity adjustment threshold and the fire alarm threshold includes:

[0012] The increment of the detection value when the trigger detector is adjusted from high sensitivity to low sensitivity is marked as Thd; the increment of the detection value when the trigger detector is adjusted from low sensitivity to high sensitivity is marked as Thu; where Thd > Thu; the fire alarm threshold is marked as Thf.

[0013] This invention avoids the detector repeatedly adjusting its working state under a certain smoke concentration by setting differentiated detector sensitivity adjustment thresholds, which is beneficial for more accurate subsequent analysis results and improves the reliability of detector operation.

[0014] Preferably, adjusting the detector's initialization state to a high-sensitivity state includes:

[0015] Adjust the current driving the transmitting tube and the conversion coefficient of the electrical signal processing module to make the detector's initial state a high-sensitivity state.

[0016] The smoke concentration signal conversion coefficient of the detector in high sensitivity state is denoted as Rh, and the smoke concentration signal conversion coefficient of the detector in low sensitivity state is denoted as Rl.

[0017] Preferably, the initialization of the detector background value includes:

[0018] Collect the smoke concentration in clean air, mark the detected value as the detector background value, and record it as Vb.

[0019] This invention sets the detector initialization state to high sensitivity and uses the detection value collected by the detector in a clean air environment as the background value, which facilitates the smooth progress of subsequent calculation and judgment processes.

[0020] Preferably, the step of periodically detecting the smoke concentration to obtain a detection value includes:

[0021] Every so often, the detector drives the transmitting tube with a pulse voltage and starts the electrical signal processing module to complete a smoke concentration detection, and marks the collected detection value as Vr.

[0022] Preferably, the periodic updating of the detector's background value includes:

[0023] Retrieve the timed acquisition of the detection value Vr and the detector's background value Vb;

[0024] When the detector is in a high-sensitivity state, the updated background value is calculated using the formula (Vr+7×Vb) / 8, and the result is assigned to Vb.

[0025] When the detector is in a low-sensitivity state, the updated background value is calculated using the formula (Vr×Rh / Rl+7×Vb) / 8, and the result is assigned to Vb.

[0026] It should be noted that each update uses a weighted sum of the detected value and the baseline value as the new baseline value. The weighting coefficients are obtained based on empirical testing; for example, the detected value has a weight of 1 / 8, and the baseline value has a weight of 7 / 8. The update cycle for the baseline value is set based on experience; for example, it is set to 4 hours.

[0027] This invention updates the detector's background value periodically, using a weighted sum of the detected value and the background value as the new background value each time. Furthermore, it corrects the detected value based on the detector's sensitivity at the time of smoke concentration collection. This makes the background value update process more stable and improves the detector's self-recovery capability under abnormal conditions.

[0028] Preferably, the adaptive adjustment of the detector's operating state based on the detected value and the background value includes:

[0029] Retrieve the detector's detection value Vr and background value Vb;

[0030] When the detector is in a high-sensitivity state, if Vr-Vb>Thd, the detector is adjusted to a low-sensitivity state; otherwise, the smoke concentration is periodically detected and the background value is updated.

[0031] When the detector is in a low-sensitivity state, if Vr×Rh / Rl-Vb<Thu is satisfied, the detector is adjusted to a high-sensitivity state; otherwise, the smoke concentration is detected periodically and the background value is updated.

[0032] This invention expands the detection range of the detector by adaptively adjusting the detector sensitivity.

[0033] Preferably, the step of alarming a fire based on the smoke concentration detection value and the detector's background value includes:

[0034] When the detector is in a high-sensitivity state, if Vr-Vb>Thf, a fire alarm signal is issued; otherwise, proceed to step S2.

[0035] When the detector is in a low-sensitivity state, if Vr×Rh / Rl-Vb>Thf, a fire alarm signal is issued; otherwise, proceed to step S2.

[0036] This invention employs a sensitivity adaptive algorithm for fire smoke alarms, ensuring that the detector has high sensitivity to low-concentration smoke while also achieving a large response range to high-concentration smoke, thus enhancing the detector's reliability.

[0037] A second aspect of the present invention provides a system for improving the anti-ash accumulation performance of smoke detectors, comprising: an optical sensing module, an electrical signal processing module, a smoke concentration acquisition module, a sensitivity adaptive adjustment module, a background value update module, and an alarm module.

[0038] The optical sensing module includes a transmitter, a receiver, and an optical darkroom, used to convert smoke concentration into an electrical signal;

[0039] Electrical signal processing module: used to amplify electrical signals and perform analog-to-digital conversion;

[0040] Smoke Concentration Acquisition Module: Used to control the working status of the optical sensing module and the electrical signal processing module, and to collect smoke concentration information at regular intervals;

[0041] Sensitivity adaptive adjustment module: used to automatically adjust the sensitivity state of the detector;

[0042] Background value update module: used to update the background value periodically;

[0043] Alarm module: Used to identify fire smoke and output alarm signals.

[0044] Compared with the prior art, the beneficial effects of the present invention are:

[0045] 1. The invention sets differentiated detector sensitivity adjustment thresholds to avoid repeated adjustments of the detector's working state under a certain smoke concentration, which is beneficial for more accurate subsequent analysis results and improves the reliability of the detector's operation.

[0046] 2. This invention periodically updates the detector's background value. Each time it is updated, the detected value and the background value are weighted and summed to obtain the new background value. Furthermore, the detected value is corrected based on the detector's sensitivity status when the smoke concentration is collected. This makes the background value update process more stable and improves the detector's self-recovery capability under abnormal conditions.

[0047] 3. This invention employs a sensitivity adaptive algorithm for fire smoke alarms, which ensures that the detector has high sensitivity to low-concentration smoke while also achieving a large response range for high-concentration smoke, resulting in higher detector reliability. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a schematic diagram illustrating the working principle of the present invention;

[0050] Figure 2 This is a schematic diagram illustrating the specific steps of the method for implementing the present invention;

[0051] Figure 3 This is a schematic diagram of the system module for improving the anti-ash accumulation performance of smoke detectors according to the present invention. Detailed Implementation

[0052] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] Please see Figure 1 The first aspect of the present invention provides a method for improving the anti-ash accumulation performance of smoke detectors, comprising:

[0054] S1. Set the detector sensitivity adjustment threshold and fire alarm threshold; adjust the detector's initialization state to high sensitivity state;

[0055] S2. Initialize the detector background value; periodically detect the smoke concentration to obtain the detection value, and periodically update the detector background value;

[0056] S3. Obtain the working status of the detector and adaptively adjust the working status of the detector based on the detected value and the background value;

[0057] S4. Alarm the fire based on the smoke concentration detection value and the detector's background value.

[0058] Please see Figure 2A specific method for improving the anti-ash accumulation performance of smoke detectors includes the following steps: setting a detector sensitivity adjustment threshold; marking the increment of the detection value when the detector is adjusted from high sensitivity to low sensitivity as Thd; marking the increment of the detection value when the detector is adjusted from low sensitivity to high sensitivity as Thu; wherein Thd > Thu; marking the fire alarm threshold as Thf; initializing the detector to a high sensitivity state; adjusting the current and electrical signal conversion coefficient of the driving transmitter to make the detector's initial state a high sensitivity state; marking the smoke concentration signal conversion coefficient of the detector in the high sensitivity state as Rh, and marking the smoke concentration signal conversion coefficient of the detector in the low sensitivity state as Rl;

[0059] Initialize the detector background value and mark it as Vb. Generate a collection signal according to the set period. Detect the smoke concentration periodically based on the collection signal. Mark the collected detection value as Vr. Update the detector background value periodically. Use the weighted sum of the detection value and the background value after each update as the new background value.

[0060] When the detector is in a high-sensitivity state, the updated background value is calculated using the formula (Vr+7×Vb) / 8, and the result is assigned to Vb. If Vr-Vb>Thd is satisfied, the detector is adjusted to a low-sensitivity state. If Vr-Vb>Thf is satisfied, a fire alarm signal is issued. Otherwise, the detector's detection value Vr is updated again.

[0061] When the detector is in a low-sensitivity state, the updated background value is calculated using the formula (Vr×Rh / Rl+7×Vb) / 8, and the result is assigned to Vb. If Vr×Rh / Rl-Vb<Thu, the detector is adjusted to high sensitivity. If Vr×Rh / Rl-Vb>Thf, a fire alarm signal is issued. Otherwise, the detector's detection value Vr is updated again.

[0062] For example: There are two detectors, A and B, where detector A is in a high-sensitivity state and detector B is in a low-sensitivity state;

[0063] At time T1, detector A calculates (Vr + 7 × Vb) / 8 and assigns the result to Vb. However, at this moment, Vr - Vb > Thd is not satisfied, so Vr is re-detected. At time T2, detector A calculates (Vr + 7 × Vb) / 8 and assigns the result to Vb. At this moment, Vr - Vb > Thd is satisfied, so the detector is adjusted to a low-sensitivity state. However, Vr - Vb > Thf is not satisfied, so Vr is re-detected. At time T3, the detector is in a low-sensitivity state, calculates (Vr × Rh / Rl + 7 × Vb) / 8 and assigns the result to Vb. Vr × Rh / Rl - Vb < Thu is satisfied, so the detector is adjusted to a high-sensitivity state. Furthermore, Vr × Rh / Rl - Vb > Thf is satisfied, so detector A issues a fire alarm signal.

[0064] At time T1, detector B calculates the formula (Vr×Rh / Rl+7×Vb) / 8 and assigns the result to Vb. However, at this moment, Vr×Rh / Rl-Vb<Thu is not satisfied, so Vr is re-detected. At time T2, detector B calculates the formula (Vr×Rh / Rl+7×Vb) / 8 and assigns the result to Vb. At this moment, Vr×Rh / Rl-Vb<Thu is satisfied, so the detector is adjusted to a high-sensitivity state. However, Vr×Rh / Rl-Vb>Thf is not satisfied, so Vr is re-detected. At time T3, the detector is in a high-sensitivity state, calculates the formula (Vr×Rh / Rl+7×Vb) / 8 and assigns the result to Vb. Vr-Vb>Thd is satisfied, so the detector is adjusted to a low-sensitivity state. At this moment, Vr-Vb>Thf is satisfied, so detector B issues a fire alarm signal.

[0065] Please see Figure 3 The second aspect of the present invention provides a system for improving the anti-ash accumulation performance of smoke detectors, including an optical sensing module, an electrical signal processing module, a smoke concentration acquisition module, a sensitivity adaptive adjustment module, a background value update module, and an alarm module.

[0066] The optical sensing module includes a transmitter, a receiver, and an optical darkroom, used to convert smoke concentration into an electrical signal;

[0067] Electrical signal processing module: used to amplify electrical signals and perform analog-to-digital conversion;

[0068] Smoke concentration acquisition module: used to control the working status of the optical sensing module and the electrical signal processing module;

[0069] Sensitivity adaptive adjustment module: used to automatically adjust the sensitivity state of the detector;

[0070] Background value update module: used to update the background value periodically;

[0071] Alarm module: Used to identify fire smoke and output alarm signals.

[0072] Some of the data in the above formula are calculated by removing dimensions and taking their numerical values. The formula is the closest to the real situation obtained by software simulation of a large amount of collected data. The preset parameters and preset thresholds in the formula are set by those skilled in the art according to the actual situation or obtained through simulation of a large amount of data.

[0073] The working principle of this invention is as follows: This invention adjusts the detector's initialization state to a high-sensitivity state and initializes the detector's background value by setting a detector sensitivity adjustment threshold and a fire alarm threshold. It also periodically detects the smoke concentration to obtain the detection value and then updates the detector's background value based on the detection value.

[0074] The system acquires the detector's operating status and adaptively adjusts it based on the detected value and background value. When the detector is in a high-sensitivity state, the updated background value is calculated using a formula to determine if a sensitivity switch is needed. If yes, the high-sensitivity state is adjusted to a low-sensitivity state; otherwise, the background value is updated periodically. When the detector is in a low-sensitivity state, the updated background value is calculated using a formula to determine if a sensitivity switch is needed. If yes, the low-sensitivity state is adjusted to a high-sensitivity state; otherwise, the background value is updated periodically. After updating the detector's background value, it is determined whether the conditions for issuing a fire alarm signal are met. If yes, an alarm is issued; otherwise, the smoke concentration is re-detected based on the detector's operating status. Finally, the re-detected value is used to determine whether a fire alarm needs to be triggered.

[0075] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A method of improving the soot resistance of a smoke detector, characterized in that, The method comprises the following steps: S1, setting a detector sensitivity adjustment threshold and a fire alarm threshold; adjusting an initial state of the detector to a high sensitivity state; S2, initializing a background value of the detector; detecting the smoke concentration to obtain a detection value at a regular time, and updating the background value of the detector at a regular time; S3, obtaining a working state of the detector, and adaptively adjusting the working state of the detector according to the detection value and the background value; S4, alarming a fire according to the smoke concentration detection value and the background value of the detector; The setting of the detector sensitivity adjustment threshold and the fire alarm threshold comprises: marking a detection value increment when the detector is triggered from the high sensitivity to the low sensitivity as Thd, marking a detection value increment when the detector is triggered from the low sensitivity to the high sensitivity as Thu, wherein Thd>Thu, and marking a fire alarm threshold as Thf; The initializing of the background value of the detector comprises: collecting a detection value of the smoke concentration in clean air, marking the detection value as the background value of the detector and recording it as Vb; The detection of the smoke concentration to obtain a detection value at a regular time comprises: generating a collection signal according to a set period, detecting the smoke concentration at a regular time based on the collection signal, marking the collected detection value as Vr, and updating the background value of the detector at a regular time; The adjusting of the initial state of the detector to the high sensitivity state comprises: adjusting a current size and an electrical signal conversion coefficient of a driving emission tube, so that the initial state of the detector is the high sensitivity state; marking a smoke concentration signal conversion coefficient of the detector in the high sensitivity state as Rh, and marking a smoke concentration signal conversion coefficient of the detector in the low sensitivity state as Rl; The adaptive adjustment of the working state of the detector according to the detection value and the background value comprises: calling the detection value Vr and the background value Vb of the detector; when the detector is in the high sensitivity state, if Vr-Vb>Thd is met, the detector is adjusted to the low sensitivity state; otherwise, the smoke concentration is detected at a regular time, and the background value is updated; when the detector is in the low sensitivity state, if Vr×Rh / Rl-Vb<Thu is met, the detector is adjusted to the high sensitivity state; otherwise, the smoke concentration is detected at a regular time, and the background value is updated.

2. The method of claim 1, wherein the method comprises, The updating of the background value of the detector at a regular time comprises: calling the detection value Vr and the background value Vb of the detector; when the detector is in the high sensitivity state, the updated background value is calculated by the formula (Vr+7×Vb) / 8, and the result is assigned to Vb; when the detector is in the low sensitivity state, the updated background value is calculated by the formula (Vr×Rh / Rl+7×Vb) / 8, and the result is assigned to Vb.

3. The method of claim 1, wherein the method comprises: The alarming of a fire according to the smoke concentration detection value and the background value of the detector comprises: when the detector is in the high sensitivity state, if Vr-Vb>Thf is met, a fire alarm signal is sent, otherwise step S2 is entered; when the detector is in the low sensitivity state, if Vr×Rh / Rl-Vb>Thf is met, a fire alarm signal is sent, otherwise step S2 is entered.

4. A system for improving the anti-fouling performance of a smoke fire detector, applied to a method for improving the anti-fouling performance of a smoke fire detector according to any one of claims 1-3, characterized in that, The method comprises the following steps: Optical sensing module, electric signal processing module, smoke concentration collecting module, sensitivity self-adaptive adjusting module, background value updating module and alarm module; The optical sensing module comprises a transmitting tube, a receiving tube and an optical darkroom, which are used for converting smoke concentration information into electric signals; The electric signal processing module is used for amplifying electric signals and realizing analog-digital conversion; The smoke concentration collecting module is used for controlling the working states of the optical sensing module and the electric signal processing module, and collecting smoke concentration information at regular time intervals; The sensitivity self-adaptive adjusting module is used for automatically adjusting the sensitivity state of the detector; The background value updating module is used for regularly updating the background value; The alarm module is used for identifying fire smoke and outputting an alarm signal.

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