A temperature compensation-based smoke concentration detection method and system

Abstract

The present application relates to the technical field of smoke concentration detection, and a smoke concentration detection method and system based on temperature compensation, comprising: receiving a smoke concentration detection instruction, confirming a smoke concentration detection system and a smoke detection area based on the smoke concentration detection instruction, obtaining double sound path echo data by using an ultrasonic receiver, a short sound path, a long sound path and a detection pulse sequence, obtaining a path temperature node by using a temperature sensor, obtaining a clean air reference propagation speed based on the path temperature node, obtaining amplitude attenuation data based on the double sound path echo data, obtaining a frequency attenuation difference amount based on the amplitude attenuation data, obtaining a smoke characteristic identifier by using a temperature compensation propagation change amount, the frequency attenuation difference amount and the path temperature node, and realizing smoke concentration detection based on the smoke characteristic identifier and an alarm. The present application can improve the accuracy of smoke concentration detection.

Description

Technical Field

[0001] This invention relates to the field of smoke concentration detection technology, and in particular to a smoke concentration detection method and system based on temperature compensation. Background Technology

[0002] Smoke concentration detection is of paramount importance in fields such as fire safety, industrial production, and environmental monitoring. In fire safety, smoke is often generated in the early stages of a fire; rapid and accurate detection of changes in smoke concentration can buy valuable time for fire warnings, effectively reducing casualties and losses. In industrial production, smoke concentration monitoring can be used in scenarios such as emission control, dust explosion prevention, and cleanroom environmental maintenance.

[0003] Traditional smoke concentration detection methods mainly rely on photoelectric scattering principles or ion sensing technology. However, these methods typically lack temperature self-compensation capabilities, and changes in ambient temperature can interfere with measurement accuracy. Especially in scenarios with large temperature gradients, the false alarm and false negative rates are high, making it difficult to meet the detection needs under complex operating conditions. Therefore, developing a smoke concentration detection method that is fast-responding, accurate, reliable, and adaptable to complex environments has become a crucial technical problem urgently needing to be solved in this field. Summary of the Invention

[0004] This invention provides a temperature-compensated smoke concentration detection method and a computer-readable storage medium, the main purpose of which is to improve the accuracy of smoke concentration detection.

[0005] To achieve the above objectives, the present invention provides a smoke concentration detection method based on temperature compensation, comprising:

[0006] The system receives a smoke concentration detection command and, based on the command, identifies the smoke concentration detection system and the smoke detection area. The smoke concentration detection system includes an ultrasonic transmitter, an ultrasonic receiver, a temperature sensor, and an alarm.

[0007] Short-path and long-path sound paths were established in the smoke test area, and the detection pulse sequence was obtained using an ultrasonic transmitter;

[0008] Two-path echo data were acquired using an ultrasound receiver, short-path, long-path, and detection pulse sequences.

[0009] Propagation time data is obtained based on dual path echo data, the actual propagation speed is calculated using the propagation time data, the path temperature nodes are obtained using temperature sensors, and the clean air reference propagation speed is obtained based on the path temperature nodes.

[0010] The temperature-compensated propagation change is obtained based on the actual propagation speed and the clean air reference propagation speed.

[0011] Amplitude attenuation data is obtained based on double path echo data, and frequency attenuation difference is obtained based on amplitude attenuation data.

[0012] Smoke feature identifiers are obtained by utilizing temperature-compensated propagation changes, frequency attenuation differences, and path temperature nodes. Smoke concentration detection is achieved based on these smoke feature identifiers and an alarm.

[0013] Optionally, acquiring the detection pulse sequence using an ultrasonic transmitter includes:

[0014] The pulse configuration node is obtained using an ultrasonic transmitter. The pulse configuration node includes: a first frequency, a second frequency, a pulse transmission duration, a pulse drive amplitude, and a pulse interval.

[0015] Obtain the start time of the detection cycle and use the start time of the detection cycle as the first launch time;

[0016] A first frequency detection pulse is generated based on the first frequency, pulse transmission duration, and pulse drive amplitude, and the first frequency detection pulse and the first transmission time are associated to obtain the first pulse identifier;

[0017] A second frequency detection pulse is generated based on the second frequency, pulse transmission duration, and pulse drive amplitude. The second transmission time is obtained based on the first transmission time and pulse interval. The second pulse identifier is obtained by associating the second frequency detection pulse with the second transmission time.

[0018] A verification detection pulse is generated based on the first frequency, pulse transmission duration, and pulse drive amplitude. The verification transmission time is obtained based on the second transmission time and pulse interval. The verification detection pulse and the verification transmission time are correlated to obtain the verification pulse identifier.

[0019] The first pulse identifier, the second pulse identifier, and the verification pulse identifier are sorted in chronological order to obtain the detection pulse sequence.

[0020] Optionally, the acquisition of two-path echo data using an ultrasonic receiver, short-path, long-path, and detection pulse sequence includes:

[0021] Obtain the short path length, long path length, short echo time window, and long echo time window;

[0022] The short-range echo set is obtained by using an ultrasonic receiver to receive the echo signal formed after the detection pulse sequence has propagated through a short acoustic path within a short echo time window.

[0023] Based on the short-range echo set, the short-range echoes corresponding to the first pulse identifier, the second pulse identifier, and the verification pulse identifier are confirmed respectively, and the first short-range identifier echo, the second short-range identifier echo, and the short-range verification echo are obtained.

[0024] A long-range echo set is obtained by using an ultrasonic receiver to receive the echo signal formed after the detection pulse sequence has propagated over a long acoustic path within a long echo time window.

[0025] Based on the long-range echo set, the long-range echoes corresponding to the first pulse identifier, the second pulse identifier, and the verification pulse identifier are confirmed respectively, and the first long-range identifier echo, the second long-range identifier echo, and the long-range verification echo are obtained.

[0026] By associating the first short-range identifier echo, the first long-range identifier echo, the short path length, and the long path length, the first double-path echo node is obtained.

[0027] By associating the second short-path marker echo, the second long-path marker echo, the short path length, and the long path length, the second double-path echo node is obtained.

[0028] By correlating the short-range core echo, the long-range core echo, the short path length, and the long path length, the core double-path echo node is obtained;

[0029] The first two-path echo node, the second two-path echo node, and the verification two-path echo node are summarized to obtain the two-path echo data.

[0030] Optionally, the acquisition of propagation time data based on two-path echo data includes:

[0031] Envelope extraction is performed on the first short-range identifier echo to obtain the short-range envelope time series. The short-range envelope time series includes multiple short-range envelope points, and each short-range envelope point includes: short-range envelope amplitude and short-range sampling time.

[0032] Obtain the main short-range peak value, multiply it by the main short-range peak value and the preset arrival ratio to obtain the main short-range arrival peak value;

[0033] Within the short-range envelope time series, the short-range sampling time corresponding to the first short-range envelope amplitude that is greater than the peak value of the main short-range arrival is identified as the short-range time.

[0034] The long-range time is obtained based on the first long-range identifier echo and the arrival ratio;

[0035] By associating the first pulse identifier, short-range time, long-range time, short-range sound path length, and long-range sound path length, the first propagation time node is obtained;

[0036] The short-range verification time and the long-range verification time are obtained from the short-range verification echo and the long-range verification echo.

[0037] By associating the verification pulse identifier, verification short-range time, verification long-range time, short sound path length, and long sound path length, the verification propagation time node is obtained;

[0038] By summarizing the first propagation time point and the verification propagation time point, propagation time data is obtained.

[0039] Optionally, the calculation of the actual propagation speed using propagation time data includes:

[0040] Calculate the time interval between the short-range time and the long-range time to obtain the main measurement time interval;

[0041] The absolute difference between the long and short sound paths is calculated to obtain the sound path difference;

[0042] The ratio of the sound path difference to the main measurement time interval is calculated to obtain the main measurement propagation velocity;

[0043] The verification propagation speed is calculated based on the short-range verification time, the long-range verification time, and the sound path difference.

[0044] The absolute difference between the primary propagation velocity and the secondary propagation velocity is calculated to obtain the periodic velocity deviation;

[0045] When the periodic velocity deviation is less than or equal to the preset velocity deviation threshold, the average of the main propagation velocity and the verification propagation velocity is calculated to obtain the actual propagation velocity.

[0046] Optionally, the step of acquiring path temperature nodes using temperature sensors and obtaining clean air reference propagation velocity based on path temperature nodes includes:

[0047] Temperature sensors were used to measure the temperature of the ultrasonic transmitter, the ultrasonic receiver, and the temperature of the smoke test area to obtain the transmitter temperature, receiver temperature, and cavity wall temperature.

[0048] Calculate the average temperature at the transmitting end and the receiving end to obtain the path average temperature;

[0049] The absolute difference between the temperature at the transmitting end and the temperature at the receiving end is calculated to obtain the path gradient temperature.

[0050] Obtain the historical average temperature of the path, calculate the difference between the path average temperature and the historical average temperature of the path, and obtain the periodic temperature change, where the path average temperature is the minuend.

[0051] By associating the average temperature along the path, the gradient temperature along the path, the periodic temperature change, and the cavity wall temperature, the path temperature nodes are obtained.

[0052] The initial reference propagation velocity is retrieved from the pre-built clean air sound velocity table using the path average temperature, the gradient correction amount is retrieved from the pre-built temperature gradient correction table using the path gradient temperature, and the thermal hysteresis correction amount is retrieved from the pre-built thermal hysteresis correction table using the periodic temperature change and the cavity wall temperature.

[0053] The clean air reference propagation velocity is obtained by summing the initial reference propagation velocity, the gradient correction, and the thermal hysteresis correction.

[0054] Optionally, the step of obtaining amplitude attenuation data based on double path echo data and obtaining frequency attenuation difference based on amplitude attenuation data includes:

[0055] The first frequency short-range amplitude is obtained based on the first short-range identifier echo, and the first frequency long-range amplitude is obtained based on the first long-range identifier echo.

[0056] The second frequency short-range amplitude is obtained based on the second short-range identifier echo, and the second frequency long-range amplitude is obtained based on the second long-range identifier echo;

[0057] By correlating the short-range amplitude of the first frequency, the long-range amplitude of the first frequency, the short-range amplitude of the second frequency, and the long-range amplitude of the second frequency, amplitude attenuation data is obtained.

[0058] The difference between the short-range amplitude of the first frequency and the long-range amplitude of the first frequency is calculated to obtain the sound path attenuation of the first frequency, where the short-range amplitude of the first frequency is the minuend.

[0059] The difference between the short-range amplitude of the second frequency and the long-range amplitude of the second frequency is calculated to obtain the sound path attenuation of the second frequency, where the short-range amplitude of the second frequency is the minuend.

[0060] Obtain clean air reference nodes, wherein the clean air reference nodes include: a first frequency reference attenuation and a second frequency reference attenuation;

[0061] The frequency attenuation difference is calculated using the sound path attenuation at the first frequency, the sound path attenuation at the second frequency, the reference attenuation at the first frequency, and the reference attenuation at the second frequency. The calculation formula is as follows:

[0062] ;

[0063] in, This indicates the difference in frequency attenuation. This indicates the sound path attenuation at the second frequency. This represents the sound path attenuation at the first frequency. This indicates the attenuation of the second frequency reference. This indicates the attenuation of the first frequency reference.

[0064] Optionally, the step of obtaining smoke feature identifiers using temperature-compensated propagation changes, frequency attenuation differences, and path temperature nodes includes:

[0065] If the absolute value of the periodic temperature change is not greater than the preset temperature stability threshold, the absolute value of the temperature compensation propagation change is greater than the preset sound speed anomaly threshold, and the frequency attenuation difference is greater than the preset attenuation anomaly threshold, then the smoke feature is marked as valid.

[0066] Otherwise, the smoke feature identifier will be marked as invalid.

[0067] Optionally, the smoke concentration detection based on smoke feature identification and alarm includes:

[0068] When the smoke feature is identified as valid, the concentration lookup table node is obtained by associating the temperature compensation propagation change, frequency attenuation difference, and path temperature node.

[0069] Use the concentration lookup table node to find the smoke concentration value in the pre-built smoke concentration calibration table;

[0070] The smoke concentration value is compared with the preset alarm threshold to obtain the concentration alarm result, where the concentration alarm result is either the alarm threshold has been reached or the alarm threshold has not been reached.

[0071] Once the concentration alarm result is confirmed to have reached the alarm threshold, the alarm device will output an alarm message.

[0072] When the smoke feature identifier is invalid, a verification detection command is generated, and the process returns to the step of obtaining the detection pulse sequence using the ultrasonic transmitter based on the verification detection command.

[0073] To achieve the above objectives, the present invention also provides a temperature-compensated smoke concentration detection system, comprising:

[0074] The instruction response module is used to receive smoke concentration detection instructions and, based on the smoke concentration detection instructions, identify the smoke concentration detection system and the smoke detection area. The smoke concentration detection system includes an ultrasonic transmitter, an ultrasonic receiver, a temperature sensor, and an alarm.

[0075] The echo data acquisition module is used to establish short-path and long-path sound in the smoke test area and to acquire the detection pulse sequence using an ultrasonic transmitter;

[0076] Two-path echo data were acquired using an ultrasound receiver, short-path, long-path, and detection pulse sequences.

[0077] The temperature compensation module is used to acquire propagation time data based on dual path echo data, calculate the actual propagation speed using the propagation time data, acquire path temperature nodes using temperature sensors, and acquire clean air reference propagation speed based on the path temperature nodes.

[0078] The temperature-compensated propagation change is obtained based on the actual propagation speed and the clean air reference propagation speed.

[0079] The smoke feature fusion module is used to obtain amplitude attenuation data based on double path echo data, and to obtain frequency attenuation difference based on amplitude attenuation data.

[0080] Smoke feature identifiers are obtained by utilizing temperature-compensated propagation changes, frequency attenuation differences, and path temperature nodes. Smoke concentration detection is achieved based on these smoke feature identifiers and an alarm.

[0081] To address the above problems, the present invention also provides an electronic device, the electronic device comprising:

[0082] Memory, storing at least one instruction;

[0083] The processor executes the instructions stored in the memory to implement the temperature-compensated smoke concentration detection method described above.

[0084] To address the aforementioned problems, the present invention also provides a computer-readable storage medium storing at least one instruction, which is executed by a processor in an electronic device to implement the temperature-compensated smoke concentration detection method described above.

[0085] To address the problems described in the background art, this invention receives a smoke concentration detection command and, based on the command, identifies the smoke concentration detection system and the smoke detection area. The smoke concentration detection system includes an ultrasonic transmitter, an ultrasonic receiver, a temperature sensor, and an alarm. Short-path and long-path sound waves are established in the smoke detection area, and the ultrasonic transmitter acquires a detection pulse sequence. This invention, by transmitting two detection pulses of different frequencies and a verification detection pulse within the same detection cycle, utilizes the scattering differences of the ultrasonic pulses at different frequencies to obtain smoke characteristics. Furthermore, the verification detection pulse independently verifies the propagation results of the first frequency, improving the detection process's resistance to occasional interference. Dual-path echo data is acquired using the ultrasonic receiver, short-path, long-path, and detection pulse sequence. This invention unifies the calculation benchmarks for sound velocity and amplitude to the same transmission event by simultaneously acquiring short-path and long-path echoes from the same detection pulse, reducing environmental disturbance errors caused by two independent transmissions. Propagation time data is acquired based on the dual-path echo data, and the actual propagation speed is calculated using this data. The temperature sensor acquires path temperature nodes, and based on the path... The invention obtains the clean air reference propagation velocity through path temperature nodes. It is evident that by employing two independent velocity measurements (primary and secondary) and deviation verification, this invention reduces the single-measurement error caused by occasional interference, providing an accurate actual propagation velocity for subsequent calculation of temperature-compensated propagation changes. The temperature-compensated propagation change is obtained based on the actual propagation velocity and the clean air reference propagation velocity. Amplitude attenuation data is obtained based on dual-path echo data, and frequency attenuation difference is obtained based on the amplitude attenuation data. This invention compares the attenuation of two different frequency ultrasound pulses (second and first frequency detection pulses) over the path difference, and subtracts inherent differences under clean air conditions. This makes the frequency attenuation difference significantly more sensitive to smoke particles than a single frequency attenuation index, reducing interference from air attenuation itself. Smoke characteristic identifiers are obtained using the temperature-compensated propagation change, frequency attenuation difference, and path temperature nodes. Smoke concentration detection is achieved based on these identifiers and an alarm. This invention maps the temperature-compensated propagation change, frequency attenuation difference, and path temperature nodes to specific smoke concentration values ​​through a smoke concentration calibration table, and reduces false alarms caused by occasional factors through verification detection, balancing detection sensitivity and reliability. Therefore, this invention improves the accuracy of smoke concentration detection. Attached Figure Description

[0086] Figure 1 This is a schematic flowchart of a temperature-compensated smoke concentration detection method according to an embodiment of the present invention.

[0087] Figure 2 A functional block diagram of a temperature-compensated smoke concentration detection system provided in an embodiment of the present invention;

[0088] Figure 3 This is a schematic diagram of the structure of an electronic device for implementing the temperature-compensated smoke concentration detection method according to an embodiment of the present invention.

[0089] Explanation of reference numerals in the attached figures:

[0090] 10. Electronic device; 11. Processor; 12. Memory; 13. Bus.

[0091] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0092] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0093] This application provides a temperature-compensated smoke concentration detection method. The executing entity of the temperature-compensated smoke concentration detection method includes, but is not limited to, at least one of the following electronic devices that can be configured to execute the method provided in this application: a server, a terminal, etc. In other words, the temperature-compensated smoke concentration detection method can be executed by software or hardware installed on a terminal device or a server device, and the software can be a blockchain platform. The server includes, but is not limited to, a single server, a server cluster, a cloud server, or a cloud server cluster.

[0094] Reference Figure 1 The diagram shown is a schematic flowchart of a temperature-compensated smoke concentration detection method according to an embodiment of the present invention. In this embodiment, the temperature-compensated smoke concentration detection method includes:

[0095] S1. Receive a smoke concentration detection command, and confirm the smoke concentration detection system and the smoke detection area based on the smoke concentration detection command. The smoke concentration detection system includes an ultrasonic transmitter, an ultrasonic receiver, a temperature sensor, and an alarm.

[0096] It should be explained that the smoke concentration detection command is issued by the personnel who wish to conduct smoke monitoring. The smoke concentration detection system is a collection of devices used for smoke concentration detection. The smoke detection area is the area where smoke monitoring is required, such as an industrial cavity. The ultrasonic transmitter is a transducer capable of emitting ultrasonic pulses at a specified frequency. The ultrasonic receiver is a transducer capable of converting echo ultrasonic signals into electrical signals. The temperature sensor is a temperature-sensing element; optionally, a thermistor can be used for this purpose. The alarm is an alarm device that outputs audible and visual signals when the smoke concentration reaches an alarm threshold.

[0097] S2. Establish short-path and long-path sound in the smoke test area, and use an ultrasonic transmitter to obtain the detection pulse sequence.

[0098] For example, the process of establishing short-path and long-path sound effects in the smoke test area is as follows: In a 1.2-meter-long industrial cavity, an ultrasonic transmitter and receiver are placed at the left end (starting end) of the cavity. A perforated reflector is placed 0.15 meters from the left end, and the inner wall of the right end (ending end) is used as the far-end reflecting surface. The short-path sound effect is the round-trip distance from the starting end to the perforated reflector, and the long-path sound effect is the round-trip distance from the starting end to the ending end. The detection pulse sequence is an ordered collection of ultrasonic pulses, containing ultrasonic pulses of different frequencies and for different purposes.

[0099] Specifically, the acquisition of the detection pulse sequence using an ultrasonic transmitter includes:

[0100] The pulse configuration node is obtained using an ultrasonic transmitter. The pulse configuration node includes: a first frequency, a second frequency, a pulse transmission duration, a pulse drive amplitude, and a pulse interval.

[0101] Obtain the start time of the detection cycle and use the start time of the detection cycle as the first launch time;

[0102] A first frequency detection pulse is generated based on the first frequency, pulse transmission duration, and pulse drive amplitude, and the first frequency detection pulse and the first transmission time are associated to obtain the first pulse identifier;

[0103] A second frequency detection pulse is generated based on the second frequency, pulse transmission duration, and pulse drive amplitude. The second transmission time is obtained based on the first transmission time and pulse interval. The second pulse identifier is obtained by associating the second frequency detection pulse with the second transmission time.

[0104] A verification detection pulse is generated based on the first frequency, pulse transmission duration, and pulse drive amplitude. The verification transmission time is obtained based on the second transmission time and pulse interval. The verification detection pulse and the verification transmission time are correlated to obtain the verification pulse identifier.

[0105] The first pulse identifier, the second pulse identifier, and the verification pulse identifier are sorted in chronological order to obtain the detection pulse sequence.

[0106] Understandably, the pulse configuration node is a set of transmission parameter records used to constrain the frequency, duration, drive amplitude, and interval of each ultrasonic pulse transmission. The first frequency and the second frequency are two different ultrasonic center frequencies; for example, the first frequency is set to 40kHz and the second frequency to 100kHz. The pulse transmission duration is the duration of each ultrasonic pulse from start to finish, for example, 50µs. The pulse drive amplitude is the voltage amplitude required to drive the ultrasonic transmitter. The pulse interval is the waiting time between the transmission times of two adjacent ultrasonic pulses, used to avoid aliasing between the echoes of the subsequent ultrasonic pulse and the previous ultrasonic pulse. It should be noted that the pulse interval must be much longer than the propagation time of a single pulse along its corresponding sound path (short or long) to ensure that the echo of the previous pulse is fully received before the next pulse is transmitted, thus avoiding echo aliasing. The first transmission time is the moment when the first frequency detection pulse begins to be transmitted. The first frequency detection pulse is an ultrasonic pulse with the first frequency as its center frequency. The first pulse identifier is a pulse record obtained by associating the first frequency detection pulse with the first transmission time. The second emission time is obtained by superimposing a pulse interval on the first emission time. The second frequency detection pulse is an ultrasonic pulse with a second frequency as its center frequency. The second pulse identifier is a pulse record obtained by associating the second frequency detection pulse with the second emission time. The verification detection pulse is an ultrasonic pulse with the same frequency, pulse emission duration, and pulse drive amplitude as the first frequency detection pulse, used to verify the first frequency detection results within the same detection cycle. The verification emission time is obtained by superimposing another pulse interval on the second emission time. The verification pulse identifier is a pulse record obtained by associating the verification detection pulse with the verification emission time.

[0107] For example, the first frequency is set to 40kHz, the second frequency to 100kHz, the pulse transmission duration to 100µs, the pulse drive amplitude to 20V, and the pulse interval to 5ms. The detection cycle starts at T0, so the first transmission time is T0, the second transmission time is T0+5ms, and the verification transmission time is T0+10ms. The resulting first pulse identifier is (40kHz, 100µs, 20V, T0), the second pulse identifier is (100kHz, 100µs, 20V, T0+5ms), and the verification pulse identifier is (40kHz, 100µs, 20V, T0+10ms). These are then sorted chronologically to obtain the detection pulse sequence. This embodiment of the invention transmits two detection pulses of different frequencies and one verification detection pulse within the same detection cycle. On the one hand, it utilizes the scattering differences of ultrasonic pulses of different frequencies to obtain smoke characteristics; on the other hand, it uses the verification detection pulse to independently verify the propagation results of the first frequency, improving the detection process's resistance to occasional interference.

[0108] S3. Obtain double-path echo data using an ultrasonic receiver, short-path, long-path, and detection pulse sequence.

[0109] Specifically, the acquisition of dual-path echo data using an ultrasonic receiver, short-path, long-path, and detection pulse sequence includes:

[0110] Obtain the short path length, long path length, short echo time window, and long echo time window;

[0111] The short-range echo set is obtained by using an ultrasonic receiver to receive the echo signal formed after the detection pulse sequence has propagated through a short acoustic path within a short echo time window.

[0112] Based on the short-range echo set, the short-range echoes corresponding to the first pulse identifier, the second pulse identifier, and the verification pulse identifier are confirmed respectively, and the first short-range identifier echo, the second short-range identifier echo, and the short-range verification echo are obtained.

[0113] A long-range echo set is obtained by using an ultrasonic receiver to receive the echo signal formed after the detection pulse sequence has propagated over a long acoustic path within a long echo time window.

[0114] Based on the long-range echo set, the long-range echoes corresponding to the first pulse identifier, the second pulse identifier, and the verification pulse identifier are confirmed respectively, and the first long-range identifier echo, the second long-range identifier echo, and the long-range verification echo are obtained.

[0115] By associating the first short-range identifier echo, the first long-range identifier echo, the short path length, and the long path length, the first double-path echo node is obtained.

[0116] By associating the second short-path marker echo, the second long-path marker echo, the short path length, and the long path length, the second double-path echo node is obtained.

[0117] By correlating the short-range core echo, the long-range core echo, the short path length, and the long path length, the core double-path echo node is obtained;

[0118] The first two-path echo node, the second two-path echo node, and the verification two-path echo node are summarized to obtain the two-path echo data.

[0119] Understandably, as in the example above, the short path is the round trip distance from the starting end (0 meters) to the perforated reflector (0.15 meters), and the long path is the round trip distance from the starting end (0 meters) to the ending end (1.2 meters). Therefore, the short path length is the length of the round trip distance from the starting end to the perforated reflector: 0.3 meters (twice 0.15 meters), and the long path length is the length of the round trip distance from the starting end to the ending end: 2.4 meters (twice 1.2 meters).

[0120] It should be explained that the short-range echo time window is the time interval during which the ultrasonic receiver begins receiving short-range echoes. The start time of the short-range echo time window is the first transmission time T0, and the end time of the short-range echo time window is: T0 + L_short / v, where L_short is the short-range length and v is the nominal speed of sound in air (340 m / s). The long-range echo time window is the time interval during which the ultrasonic receiver begins receiving long-range echoes. The setting method for the long-range echo time window is the same as that for the short-range echo time window, and will not be repeated here. The short-range echo set is the collection of all short-range echoes received by the ultrasonic receiver within the short-range echo time window. Each short-range echo in the short-range echo set corresponds to one detection pulse.

[0121] For example, the process of confirming the short-range echoes corresponding to the first pulse identifier, the second pulse identifier, and the verification pulse identifier based on the short-range echo set to obtain the first short-range identifier echo, the second short-range identifier echo, and the short-range verification echo is as follows: Based on the emission time in each pulse identifier and the known short path length, combined with the nominal speed of sound in air, the theoretical arrival time of the short-range echo corresponding to each pulse is calculated. Then, the short-range echoes are matched in chronological order in the short-range echo set, and the short-range echoes whose actual arrival time deviates from the theoretical arrival time of the short-range echo within a preset tolerance range are confirmed as the short-range echoes of the corresponding pulse. For example, the theoretical short-range echo arrival time of the first pulse identifier (emission time T0) is T0+L_short / v, and the theoretical short path length of the second pulse identifier (emission time T0+5ms) is... The arrival time of the short-range echo is T0+5ms+L_short / v, and the theoretical arrival time of the short-range echo of the verification pulse marker (transmission time T0+10ms) is T0+10ms+L_short / v. Since the pulse interval (5ms) is much larger than the short-range propagation time (e.g., 0.882ms: 0.3m / 340m / s), the short-range echoes are arranged sequentially on the time axis and do not overlap. Therefore, the first arriving short-range echo in the short-range echo set is identified as the first short-range marker echo, the second arriving short-range echo is identified as the second short-range marker echo, and the third arriving short-range echo is identified as the short-range verification echo. The accuracy of the matching is confirmed by verifying whether the deviation between the actual arrival time and the theoretical short-range echo arrival time is within the tolerance range (e.g., ±50μs). For example, when the short path length L_short = 0.3m and the nominal speed of sound v = 340m / s, the propagation time is approximately 0.882ms. Therefore, the first short-range identifier echo arrives at approximately T0 + 0.882ms, the second short-range identifier echo arrives at approximately T0 + 5.882ms, and the short-range verification echo arrives at approximately T0 + 10.882ms. Matching can be completed in this order.

[0122] It is understood that the first short-range identifier echo is the short-range echo corresponding to the first pulse identifier, the second short-range identifier echo is the short-range echo corresponding to the second pulse identifier, and the short-range verification echo is the short-range echo corresponding to the verification pulse identifier. The confirmation method for the long-range echo set and the first long-range identifier echo, the second long-range identifier echo, and the long-range verification echo is the same as that for the short-range echo, and will not be repeated here. The first dual-path echo node is an echo record obtained by associating the short-range echo and long-range echo of the first frequency detection pulse with the short-range path length and the long-range path length. The association method for the second dual-path echo node and the verification dual-path echo node is the same as that for the first dual-path echo node. This embodiment of the invention, by simultaneously acquiring short-range and long-range echoes for the same detection pulse, unifies the calculation benchmark of sound velocity and amplitude to the same transmission event, reducing the environmental disturbance error caused by two independent transmissions.

[0123] S4. Based on the double path echo data, obtain the propagation time data, calculate the actual propagation speed using the propagation time data, obtain the path temperature nodes using the temperature sensor, and obtain the clean air reference propagation speed based on the path temperature nodes.

[0124] It should be explained that the propagation time data is a set of time data consisting of the short-range and long-range times corresponding to the first frequency detection pulse and the verification detection pulse, respectively. The actual propagation speed is the propagation speed of the ultrasonic pulse over a path difference in the current smoke-filled test area, where the path difference is the difference between the long and short path lengths. The path temperature node is a temperature record describing the current temperature conditions of the transmitter, receiver, and cavity wall. The clean air reference propagation speed is the theoretical propagation speed of the ultrasonic pulse in the air under smoke-free conditions and the same temperature. Unlike the nominal speed of sound in air, the clean air reference propagation speed is not a fixed constant, but a theoretical speed of sound dynamically calculated based on the path temperature nodes measured by the temperature sensor.

[0125] It should be understood that, because the echo signal of an ultrasonic pulse has an onset and a tail, directly using the moment when the echo first reaches its peak value as the arrival time is easily subject to noise interference. Therefore, a certain percentage of the peak value needs to be used as an arrival threshold to confirm the arrival time. Thus, the acquisition of propagation time data based on two-path echo data includes:

[0126] Envelope extraction is performed on the first short-range identifier echo to obtain the short-range envelope time series. The short-range envelope time series includes multiple short-range envelope points, and each short-range envelope point includes: short-range envelope amplitude and short-range sampling time.

[0127] Obtain the main short-range peak value, multiply it by the main short-range peak value and the preset arrival ratio to obtain the main short-range arrival peak value;

[0128] Within the short-range envelope time series, the short-range sampling time corresponding to the first short-range envelope amplitude that is greater than the peak value of the main short-range arrival is identified as the short-range time.

[0129] The long-range time is obtained based on the first long-range identifier echo and the arrival ratio;

[0130] By associating the first pulse identifier, short-range time, long-range time, short-range sound path length, and long-range sound path length, the first propagation time node is obtained;

[0131] The short-range verification time and the long-range verification time are obtained from the short-range verification echo and the long-range verification echo.

[0132] By associating the verification pulse identifier, verification short-range time, verification long-range time, short sound path length, and long sound path length, the verification propagation time node is obtained;

[0133] By summarizing the first propagation time point and the verification propagation time point, propagation time data is obtained.

[0134] Understandably, the envelope extraction is the process of taking the absolute value of the pulse drive amplitude of the first short-range identifier echo, performing low-pass filtering, and removing high-frequency oscillation components to obtain a smooth waveform. Optionally, full-wave rectification plus low-pass filtering can achieve this purpose. The short-range envelope timing sequence is a set of short-range envelope points arranged according to the short-range sampling time after envelope extraction. The short-range envelope amplitude is the envelope voltage value at the short-range sampling time. The short-range sampling time is the position of the sampling point on the time axis. The main measured short-range peak value is the maximum value among all short-range envelope amplitudes in the short-range envelope timing sequence. The arrival ratio is a proportional coefficient for determining whether the first short-range identifier echo has arrived effectively. The arrival ratio is obtained by: collecting multiple short-range echoes under multiple clean air conditions, performing envelope extraction on each short-range echo to obtain a short-range echo waveform, finding the position where the amplitude reaches 20% of its own peak value in the short-range echo waveform, recording the proportion of the time point at this position to the total time of the entire rise phase as a candidate ratio, and taking the average of all candidate ratios as the arrival ratio. The primary short-range arrival peak value is used to determine the amplitude of the first short-range identifier echo arrival time. The short-range time is the short-range sampling time corresponding to the first short-range envelope point in the short-range envelope time sequence that is greater than the primary short-range arrival peak value. The long-range time is obtained in the same way as the short-range time. The first propagation time node is a propagation time record obtained by associating the first pulse identifier, short-range time, long-range time, short path length, and long path length. The verification short-range time and verification long-range time are obtained in the same way as the short-range time and long-range time. The verification propagation time node is a propagation time record obtained by associating the verification pulse identifier, verification short-range time, verification long-range time, short path length, and long path length. This embodiment of the invention determines the echo arrival time by introducing envelope extraction and arrival ratio thresholds, avoiding noise interference when using the maximum peak value or zero crossing point as the arrival time, and ensuring that the propagation time data remains stable under low signal-to-noise ratio conditions.

[0135] Furthermore, considering that the actual propagation speed directly determines the accuracy of subsequent temperature-compensated propagation changes, it is necessary to calculate the primary propagation speed and the secondary propagation speed based on propagation time data. Specifically, the calculation of the actual propagation speed using propagation time data includes:

[0136] Calculate the time interval between the short-range time and the long-range time to obtain the main measurement time interval;

[0137] The absolute difference between the long and short sound paths is calculated to obtain the sound path difference;

[0138] The ratio of the sound path difference to the main measurement time interval is calculated to obtain the main measurement propagation velocity;

[0139] The verification propagation speed is calculated based on the short-range verification time, the long-range verification time, and the sound path difference.

[0140] The absolute difference between the primary propagation velocity and the secondary propagation velocity is calculated to obtain the periodic velocity deviation;

[0141] When the periodic velocity deviation is less than or equal to the preset velocity deviation threshold, the average of the main propagation velocity and the verification propagation velocity is calculated to obtain the actual propagation velocity.

[0142] It should be understood that the main measurement time interval represents the actual propagation time difference between the first frequency detection pulse (the same transmission event) and the ultrasonic receiver, respectively, after traveling through short and long sound paths. Both the main measurement propagation velocity and the verification propagation velocity are measured values ​​of the ultrasonic wave propagation velocity in the current medium, calculated based on the sound path difference and the time interval. The difference lies in the time interval corresponding to the main measurement propagation velocity, which is the main measurement time interval, while the time interval corresponding to the verification propagation velocity is the actual propagation time difference between the verification detection pulse (another independent transmission event) and the ultrasonic receiver, respectively, after traveling through short and long sound paths. The calculation method for the verification propagation velocity is the same as that for the main measurement propagation velocity, and will not be elaborated further here. The periodic velocity deviation is used to measure the consistency between two velocity measurement results within the current period. The velocity deviation threshold is a threshold value for judging whether the main measurement propagation velocity and the verification propagation velocity are consistent. By collecting two sets of velocity measurement data under multiple clean air environments, the upper limit of the deviation distribution (3σ) is taken as the velocity deviation threshold. The purpose of this invention in calculating the actual propagation speed using a combination of primary measurement and verification is twofold: if a measurement deviates due to occasional interference, resulting in a significant discrepancy between the two results, a remeasurement is triggered. This avoids the transmission of single-shot abnormal data to subsequent smoke detection stages, reducing false alarm rates. If the two results are consistent, the arithmetic mean is taken as the actual propagation speed. The cancellation characteristic of independent random errors makes the measurement accuracy superior to a single measurement. This embodiment of the invention reduces single-shot velocity measurement errors caused by occasional interference through two independent velocity measurements (primary and verification) and deviation verification, providing an accurate actual propagation speed for subsequent calculations of temperature-compensated propagation changes.

[0143] Furthermore, considering that the speed of sound propagation in air is greatly affected by temperature, if temperature-induced changes in the speed of sound are not compensated for, the changes in the speed of sound caused by temperature will be misinterpreted as changes in the speed of sound caused by smoke. Therefore, it is necessary to construct path temperature nodes based on multiple temperature points measured by temperature sensors and obtain the clean air reference propagation speed accordingly. Specifically, the process of obtaining path temperature nodes using temperature sensors and obtaining the clean air reference propagation speed based on the path temperature nodes includes:

[0144] Temperature sensors were used to measure the temperature of the ultrasonic transmitter, the ultrasonic receiver, and the temperature of the smoke test area to obtain the transmitter temperature, receiver temperature, and cavity wall temperature.

[0145] Calculate the average temperature at the transmitting end and the receiving end to obtain the path average temperature;

[0146] The absolute difference between the temperature at the transmitting end and the temperature at the receiving end is calculated to obtain the path gradient temperature.

[0147] Obtain the historical average temperature of the path, calculate the difference between the path average temperature and the historical average temperature of the path, and obtain the periodic temperature change, where the path average temperature is the minuend.

[0148] By associating the average temperature along the path, the gradient temperature along the path, the periodic temperature change, and the cavity wall temperature, the path temperature nodes are obtained.

[0149] The initial reference propagation velocity is retrieved from the pre-built clean air sound velocity table using the path average temperature, the gradient correction amount is retrieved from the pre-built temperature gradient correction table using the path gradient temperature, and the thermal hysteresis correction amount is retrieved from the pre-built thermal hysteresis correction table using the periodic temperature change and the cavity wall temperature.

[0150] The clean air reference propagation velocity is obtained by summing the initial reference propagation velocity, the gradient correction, and the thermal hysteresis correction.

[0151] Understandably, the transmitter temperature, receiver temperature, and cavity wall temperature are the temperature values ​​measured by temperature sensors at the ultrasonic transmitter, ultrasonic receiver, and cavity wall of the smoke test area, respectively. Since the ultrasonic transmitter and receiver are located on the same side of the smoke test area, the transmitter temperature and receiver temperature are numerically consistent. Their arithmetic mean is used to characterize the local temperature reference at the starting point, eliminating the influence of measurement errors from a single temperature sensor. The path gradient temperature characterizes the degree of temperature imbalance between the transmitter and receiver on the same side; typically, the path gradient temperature approaches zero. The cavity wall temperature characterizes the temperature conditions of the cavity environment along the sound path. The historical path average temperature is the path average temperature calculated in the previous detection cycle. The periodic temperature change reflects the trend of local temperature change at the starting point between two adjacent detections. The path temperature node is a temperature record obtained by associating the path average temperature, path gradient temperature, periodic temperature change, and cavity wall temperature.

[0152] It should be explained that the clean air velocity meter is a table that records the correspondence between the average path temperature and the ultrasonic propagation speed in a smoke-free clean air environment, measured point by point in temperature steps (e.g., from -10°C to 60°C, every 1°C). It is used to look up the theoretical sound velocity value under clean air by using the current average path temperature as an index. The clean air velocity meter is obtained by scanning the temperature from -10°C to 60°C in a smoke-free clean air environment, measuring point by point and saving the correspondence between the average path temperature and the ultrasonic propagation speed.

[0153] Furthermore, the initial reference propagation speed is the theoretical sound speed in clean air obtained by looking up a table in the clean air sound speed table, using the average temperature of the current path as an index. The temperature gradient correction table is a pre-constructed table of correspondence between path gradient temperature and sound speed correction amount, built by measuring sound speed deviations under different temperature gradients in clean air. It is used to correct sound speed errors introduced by temperature inhomogeneity within the sound path. The gradient correction amount is the sound speed correction value obtained by looking up a table in the temperature gradient correction table, using the path gradient temperature as an index. The thermal hysteresis correction table is a pre-constructed table of correspondence between the average path temperature and the actual air temperature within the area during temperature changes in the smoke test area. It is used to correct sound speed compensation errors introduced by temperature sensor response hysteresis. The index of the thermal hysteresis correction table is the periodic temperature change and the cavity wall temperature. The thermal hysteresis correction amount is the correction value obtained by looking up a table in the thermal hysteresis correction table, using the periodic temperature change and the cavity wall temperature as a combined index. This invention collects temperatures at multiple points, including the transmitter, receiver, and cavity wall, and uses a clean air sound velocity meter, temperature gradient correction table, and thermal hysteresis correction table for joint correction. This ensures that the clean air reference propagation velocity closely matches the current actual temperature conditions, providing an accurate comparison benchmark for subsequent temperature compensation propagation changes.

[0154] S5. Obtain the temperature-compensated propagation change based on the actual propagation speed and the clean air reference propagation speed.

[0155] It should be explained that the temperature-compensated propagation change is the difference in propagation speed obtained by subtracting the actual propagation speed from the clean air reference propagation speed. Since the clean air reference propagation speed completely eliminates the influence of temperature on the ultrasonic propagation speed, the difference between the actual propagation speed and the clean air reference propagation speed represents the influence of non-temperature factors such as smoke particles on the ultrasonic propagation speed. This embodiment of the invention obtains the temperature-compensated propagation change by subtracting the actual propagation speed from the clean air reference propagation speed, thus eliminating the temperature component from the sound velocity signal and allowing the remaining component to primarily reflect the influence of smoke particles on the ultrasonic propagation characteristics.

[0156] S6. Obtain amplitude attenuation data based on double path echo data, and obtain frequency attenuation difference based on amplitude attenuation data.

[0157] It should be explained that the amplitude attenuation data is a set of data composed of the amplitudes collected by the first frequency detection pulse and the second frequency detection pulse at short and long sound paths, respectively. The frequency attenuation difference is the difference between the attenuation difference of the first frequency detection pulse and the second frequency detection pulse at the same sound path difference in the smoke test area and the attenuation difference at the same sound path difference in clean air, used to highlight the differentiated attenuation effect of smoke particles on ultrasound of different frequencies.

[0158] It should be understood that, considering the different scattering and absorption characteristics of ultrasound at different frequencies in smoke particles, it is necessary to extract smoke features by comparing the amplitude attenuation of the first frequency detection pulse and the second frequency detection pulse under short and long sound paths. Therefore, the process of obtaining amplitude attenuation data based on double-path echo data and obtaining frequency attenuation difference based on amplitude attenuation data includes:

[0159] The first frequency short-range amplitude is obtained based on the first short-range identifier echo, and the first frequency long-range amplitude is obtained based on the first long-range identifier echo.

[0160] The second frequency short-range amplitude is obtained based on the second short-range identifier echo, and the second frequency long-range amplitude is obtained based on the second long-range identifier echo;

[0161] By correlating the short-range amplitude of the first frequency, the long-range amplitude of the first frequency, the short-range amplitude of the second frequency, and the long-range amplitude of the second frequency, amplitude attenuation data is obtained.

[0162] The difference between the short-range amplitude of the first frequency and the long-range amplitude of the first frequency is calculated to obtain the sound path attenuation of the first frequency, where the short-range amplitude of the first frequency is the minuend.

[0163] The difference between the short-range amplitude of the second frequency and the long-range amplitude of the second frequency is calculated to obtain the sound path attenuation of the second frequency, where the short-range amplitude of the second frequency is the minuend.

[0164] Obtain clean air reference nodes, wherein the clean air reference nodes include: a first frequency reference attenuation and a second frequency reference attenuation;

[0165] The frequency attenuation difference is calculated using the sound path attenuation at the first frequency, the sound path attenuation at the second frequency, the reference attenuation at the first frequency, and the reference attenuation at the second frequency. The calculation formula is as follows:

[0166] ;

[0167] in, This indicates the difference in frequency attenuation. This indicates the sound path attenuation at the second frequency. This represents the sound path attenuation at the first frequency. This indicates the attenuation of the second frequency reference. This indicates the attenuation of the first frequency reference.

[0168] Understandably, the first frequency short-range amplitude and the first frequency long-range amplitude are the maximum values ​​of the main measured amplitudes after envelope extraction of the first short-range and first long-range identifier echoes, respectively. The second frequency short-range amplitude and the second frequency long-range amplitude are the maximum values ​​of the main measured amplitudes after envelope extraction of the second short-range and second long-range identifier echoes, respectively. The amplitude attenuation data is an amplitude record obtained by associating the first frequency short-range amplitude, the first frequency long-range amplitude, the second frequency short-range amplitude, and the second frequency long-range amplitude together. The first frequency sound path attenuation is the difference between the first frequency short-range amplitude and the first frequency long-range amplitude, used to characterize the natural attenuation degree of the first frequency detection pulse over the sound path difference length. The second frequency sound path attenuation is the difference between the second frequency short-range amplitude and the second frequency long-range amplitude, used to characterize the natural attenuation degree of the second frequency detection pulse over the sound path difference length. The clean air reference node is a reference record obtained by placing the smoke test area in a clean air environment and recording the attenuation values ​​of the first frequency detection pulse and the second frequency detection pulse along the sound path difference length using the same emission parameters. It includes the first frequency reference attenuation and the second frequency reference attenuation. The first frequency reference attenuation and the second frequency reference attenuation are the amplitude attenuation reference values ​​of the first frequency detection pulse and the second frequency detection pulse after propagation along the sound path difference length in a clean air environment, respectively, and can be used as a reference zero point for measured attenuation at the same frequency in a smoke environment.

[0169] For example, assuming that the short-range amplitude of the first frequency detection pulse (e.g., 40kHz) is measured to be 1000mV and the long-range amplitude is 800mV under clean air calibration, then the first frequency reference attenuation is 200mV. If the short-range amplitude of the second frequency detection pulse (e.g., 100kHz) is 1000mV and the long-range amplitude is 600mV, then the second frequency reference attenuation is 400mV. If, in a smoke-filled testing area, the measured short-range amplitude of the first frequency is 1000mV and the long-range amplitude is 650mV, then the first frequency sound path attenuation is 350mV. If the short-range amplitude of the second frequency is 1000mV and the long-range amplitude is 100mV, then the second frequency sound path attenuation is 900mV. The calculated frequency attenuation difference is 350mV. The formula for calculating the frequency attenuation difference means first calculating the attenuation difference between the second and first frequency detection pulses in this test, then subtracting the attenuation difference between the second and first frequency detection pulses under clean air conditions. This eliminates the inherent differences caused by factors other than smoke particles, retaining only the differential attenuation effect between the second and first frequency detection pulses caused by smoke particles. It should be noted that the theoretical value of the frequency attenuation difference should be 0 in a smoke-free environment, while in this example, the calculated frequency attenuation difference is 350mV, indicating the presence of significant smoke particles in the current smoke-tested area. Specifically, due to the scattering and absorption of smoke particles, the attenuation of high frequencies (100kHz) is significantly increased compared to the clean air baseline, and the increase is much greater than that of low frequencies (40kHz), resulting in a dual-frequency attenuation difference from 200mV under clean air conditions. =400mV-200mV) expands to 550mV under the smoke test area ( =900mV-350mV), the 350mV difference is entirely attributed to the selective attenuation effect of smoke particles on ultrasonic frequencies. This embodiment of the invention compares the attenuation of two different ultrasonic frequencies (a second frequency detection pulse and a first frequency detection pulse) over the path difference, and subtracts the inherent differences under clean air conditions. This makes the sensitivity of the frequency attenuation difference to smoke particles significantly higher than that of a single frequency attenuation index, reducing interference from air attenuation itself.

[0170] S7. Obtain smoke feature identifiers by utilizing temperature compensation propagation change, frequency attenuation difference, and path temperature nodes, and realize smoke concentration detection based on smoke feature identifiers and alarms.

[0171] It should be explained that the smoke feature identifier is a binary identifier determined by comprehensively considering the temperature-compensated propagation change, frequency attenuation difference, and path temperature nodes. This identifier indicates whether the smoke feature is valid in the current detection cycle. When the smoke feature identifier is valid, the alarm is activated; when the smoke feature identifier is invalid, a verification detection is initiated to avoid false alarms.

[0172] Furthermore, considering that a single indicator is easily affected by sudden temperature changes or environmental noise interference, both abnormal sound velocity and abnormal attenuation must be satisfied simultaneously under the premise of stable path temperature to confirm the existence of smoke characteristics. Therefore, the method of obtaining smoke characteristic identifiers using temperature-compensated propagation changes, frequency attenuation differences, and path temperature nodes includes:

[0173] If the absolute value of the periodic temperature change is not greater than the preset temperature stability threshold, the absolute value of the temperature compensation propagation change is greater than the preset sound speed anomaly threshold, and the frequency attenuation difference is greater than the preset attenuation anomaly threshold, then the smoke feature identifier is marked as valid.

[0174] Otherwise, the smoke feature identifier will be marked as invalid.

[0175] It should be understood that the temperature stability threshold is a threshold value for determining whether the path temperature is in a stable state. It is determined by statistically analyzing the average temperature difference between two adjacent detection cycles under multiple clean air conditions, and the upper limit of the distribution is taken as the temperature stability threshold. The sound velocity anomaly threshold is a threshold value for determining whether the deviation between the actual propagation velocity and the clean air reference propagation velocity exceeds the normal fluctuation range. It is determined by statistically analyzing the propagation velocity deviation under multiple clean air conditions, and the upper limit of 3σ is taken as the sound velocity anomaly threshold. The attenuation anomaly threshold is a threshold value for determining whether the attenuation difference between the first frequency detection pulse and the second frequency detection pulse exceeds the normal fluctuation range. It is determined by statistically analyzing the frequency attenuation difference under multiple clean air conditions, and the upper limit of 3σ is taken as the attenuation anomaly threshold. This embodiment of the invention uses a combined judgment of three conditions—temperature stability, sound velocity anomaly, and attenuation anomaly—to avoid misjudgments caused by environmental disturbances due to a single indicator, thus giving the determination of the smoke feature identifier a high degree of anti-interference capability.

[0176] Furthermore, considering that when a smoke feature identifier is valid, a specific smoke concentration value needs to be obtained by looking up a table to determine whether to trigger an alarm, and when a smoke feature identifier is invalid, a verification test is needed to reduce false alarms, therefore, the smoke concentration detection based on smoke feature identifiers and alarms includes:

[0177] When the smoke feature is identified as valid, the concentration lookup table node is obtained by associating the temperature compensation propagation change, frequency attenuation difference, and path temperature node.

[0178] Use the concentration lookup table node to find the smoke concentration value in the pre-built smoke concentration calibration table;

[0179] The smoke concentration value is compared with the preset alarm threshold to obtain the concentration alarm result, where the concentration alarm result is either the alarm threshold has been reached or the alarm threshold has not been reached.

[0180] Once the concentration alarm result is confirmed to have reached the alarm threshold, the alarm device will output an alarm message.

[0181] When the smoke feature identifier is invalid, a verification detection command is generated, and the process returns to the step of obtaining the detection pulse sequence using the ultrasonic transmitter based on the verification detection command.

[0182] Understandably, the concentration lookup node is a lookup input record obtained by associating the temperature-compensated propagation change, frequency attenuation difference, and path temperature node together. The smoke concentration calibration table is a concentration correspondence table obtained by spraying standard smoke of different known concentrations and collecting the temperature-compensated propagation change, frequency attenuation difference, and path temperature node at each point. The smoke concentration value is the concentration value obtained by looking up the smoke concentration in the smoke concentration calibration table based on the concentration lookup node. The alarm threshold is the threshold for determining whether the smoke concentration requires an alarm, and can be set according to the relevant requirements of the fire automatic alarm system design specifications. The concentration alarm result is the result of comparing the smoke concentration value with the alarm threshold. The alarm information consists of audible and visual signals; after receiving the alarm information, the alarm device simultaneously outputs a buzzer sound and a flashing light. The verification detection instruction is an instruction generated when the smoke feature identifier is not valid, used to return to the execution of the step in S2 where the detection pulse sequence is obtained using the ultrasonic transmitter, to achieve re-acquisition and judgment of the current detection. In this embodiment of the invention, the temperature-compensated propagation change, frequency attenuation difference, and path temperature node are mapped to specific smoke concentration values ​​through a smoke concentration calibration table. The verification detection method reduces false alarms caused by occasional factors, thus balancing detection sensitivity and reliability.

[0183] It should be understood that, in addition to issuing an alarm, this embodiment of the invention can also execute pre-set instructions to dispatch corresponding equipment or machinery to complete predetermined tasks. For example, if an alarm threshold is detected, an alarm is triggered and pre-confirmed fire mist sprinklers are activated.

[0184] To address the problems described in the background art, this invention receives a smoke concentration detection command and, based on the command, identifies the smoke concentration detection system and the smoke detection area. The smoke concentration detection system includes an ultrasonic transmitter, an ultrasonic receiver, a temperature sensor, and an alarm. Short-path and long-path sound waves are established in the smoke detection area, and the ultrasonic transmitter acquires a detection pulse sequence. This invention, by transmitting two detection pulses of different frequencies and a verification detection pulse within the same detection cycle, utilizes the scattering differences of the ultrasonic pulses at different frequencies to obtain smoke characteristics. Furthermore, the verification detection pulse independently verifies the propagation results of the first frequency, improving the detection process's resistance to occasional interference. Dual-path echo data is acquired using the ultrasonic receiver, short-path, long-path, and detection pulse sequence. This invention unifies the calculation benchmarks for sound velocity and amplitude to the same transmission event by simultaneously acquiring short-path and long-path echoes from the same detection pulse, reducing environmental disturbance errors caused by two independent transmissions. Propagation time data is acquired based on the dual-path echo data, and the actual propagation speed is calculated using this data. The temperature sensor acquires path temperature nodes, and based on the path... The invention obtains the clean air reference propagation velocity through path temperature nodes. It is evident that by employing two independent velocity measurements (primary and secondary) and deviation verification, this invention reduces the single-measurement error caused by occasional interference, providing an accurate actual propagation velocity for subsequent calculation of temperature-compensated propagation changes. The temperature-compensated propagation change is obtained based on the actual propagation velocity and the clean air reference propagation velocity. Amplitude attenuation data is obtained based on dual-path echo data, and frequency attenuation difference is obtained based on the amplitude attenuation data. This invention compares the attenuation of two different frequency ultrasound pulses (second and first frequency detection pulses) over the path difference, and subtracts inherent differences under clean air conditions. This makes the frequency attenuation difference significantly more sensitive to smoke particles than a single frequency attenuation index, reducing interference from air attenuation itself. Smoke characteristic identifiers are obtained using the temperature-compensated propagation change, frequency attenuation difference, and path temperature nodes. Smoke concentration detection is achieved based on these identifiers and an alarm. This invention maps the temperature-compensated propagation change, frequency attenuation difference, and path temperature nodes to specific smoke concentration values ​​through a smoke concentration calibration table, and reduces false alarms caused by occasional factors through verification detection, balancing detection sensitivity and reliability. Therefore, this invention improves the accuracy of smoke concentration detection.

[0185] like Figure 2 The diagram shown is a functional block diagram of a temperature-compensated smoke concentration detection system provided in an embodiment of the present invention.

[0186] The temperature-compensated smoke concentration detection system 100 of this invention can be installed in an electronic device. Depending on the functions implemented, the temperature-compensated smoke concentration detection system 100 may include an instruction response module 101, an echo data acquisition module 102, a temperature compensation module 103, and a smoke feature fusion module 104. The module described in this invention can also be called a unit, which refers to a series of computer program segments that can be executed by the processor of an electronic device and can perform a fixed function, and which are stored in the memory of the electronic device.

[0187] The instruction response module 101 is used to receive a smoke concentration detection instruction and, based on the smoke concentration detection instruction, identify the smoke concentration detection system and the smoke detection area. The smoke concentration detection system includes an ultrasonic transmitter, an ultrasonic receiver, a temperature sensor, and an alarm.

[0188] The echo data acquisition module 102 is used to establish short-path and long-path sound in the smoke test area and to acquire the detection pulse sequence using an ultrasonic transmitter.

[0189] Two-path echo data were acquired using an ultrasound receiver, short-path, long-path, and detection pulse sequences.

[0190] The temperature compensation module 103 is used to acquire propagation time data based on double path echo data, calculate the actual propagation speed using the propagation time data, acquire path temperature nodes using temperature sensors, and acquire clean air reference propagation speed based on the path temperature nodes.

[0191] The temperature-compensated propagation change is obtained based on the actual propagation speed and the clean air reference propagation speed.

[0192] The smoke feature fusion module 104 is used to obtain amplitude attenuation data based on double path echo data and to obtain frequency attenuation difference based on amplitude attenuation data.

[0193] Smoke feature identifiers are obtained by utilizing temperature-compensated propagation changes, frequency attenuation differences, and path temperature nodes. Smoke concentration detection is achieved based on these smoke feature identifiers and an alarm.

[0194] In detail, the modules in the temperature-compensated smoke concentration detection system 100 described in this embodiment of the invention employ the same methods as described above during use. Figure 1 The method used is the same as the temperature-compensated smoke concentration detection method described in the previous article, and can produce the same technical effect, so it will not be repeated here.

[0195] like Figure 3 The diagram shown is a schematic representation of an electronic device for implementing a temperature-compensated smoke concentration detection method according to an embodiment of the present invention.

[0196] The electronic device 1 may include a processor 10, a memory 11 and a bus 12, and may also include a computer program stored in the memory 11 and executable on the processor 10, such as a smoke concentration detection method program based on temperature compensation.

[0197] The memory 11 includes at least one type of readable storage medium, such as flash memory, portable hard drive, multimedia card, card-type memory (e.g., SD or DX memory), magnetic memory, disk, optical disk, etc. In some embodiments, the memory 11 can be an internal storage unit of the electronic device 1, such as a portable hard drive. In other embodiments, the memory 11 can be an external storage device of the electronic device 1, such as a plug-in portable hard drive, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the electronic device 1. Furthermore, the memory 11 includes both internal storage units and external storage devices of the electronic device 1. The memory 11 can be used not only to store application software and various types of data installed on the electronic device 1, such as the code of a smoke concentration detection method program based on temperature compensation, but also to temporarily store data that has been output or will be output.

[0198] In some embodiments, the processor 10 may be composed of integrated circuits, such as a single packaged integrated circuit or multiple integrated circuits with the same or different functions, including combinations of one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and various control chips. The processor 10 is the control unit of the electronic device, connecting various components of the entire electronic device through various interfaces and lines. It executes programs or modules stored in the memory 11 (e.g., a smoke concentration detection method program based on temperature compensation) and calls data stored in the memory 11 to perform various functions of the electronic device 1 and process data.

[0199] The bus 12 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus 12 can be divided into an address bus, a data bus, a control bus, etc. The bus 12 is configured to realize the connection and communication between the memory 11 and at least one processor 10, etc.

[0200] Figure 3 Only electronic devices with components are shown; it will be understood by those skilled in the art that... Figure 3 The structure shown does not constitute a limitation on the electronic device 1, and may include fewer or more components than shown, or combine certain components, or have different component arrangements.

[0201] For example, although not shown, the electronic device 1 may also include a power supply (such as a battery) to power the various components. Preferably, the power supply can be logically connected to the at least one processor 10 through a power management device, thereby enabling functions such as charging management, discharging management, and power consumption management. The power supply may also include one or more DC or AC power supplies, recharging devices, power fault detection circuits, power converters or inverters, power status indicators, and other arbitrary components. The electronic device 1 may also include various sensors, Bluetooth modules, Wi-Fi modules, etc., which will not be described in detail here.

[0202] Furthermore, the electronic device 1 may also include a network interface. Optionally, the network interface may include a wired interface and / or a wireless interface (such as a Wi-Fi interface, a Bluetooth interface, etc.), which is typically used to establish communication connections between the electronic device 1 and other electronic devices.

[0203] Optionally, the electronic device 1 may further include a user interface, which may be a display, an input unit (such as a keyboard), and optionally, a standard wired interface or a wireless interface. Optionally, in some embodiments, the display may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen, etc. The display may also be appropriately referred to as a screen or display unit, used to display information processed in the electronic device 1 and to display a visual user interface.

[0204] The smoke concentration detection method program based on temperature compensation stored in the memory 11 of the electronic device 1 is a combination of multiple instructions. When run in the processor 10, it can achieve the following:

[0205] The system receives a smoke concentration detection command and, based on the command, identifies the smoke concentration detection system and the smoke detection area. The smoke concentration detection system includes an ultrasonic transmitter, an ultrasonic receiver, a temperature sensor, and an alarm.

[0206] Short-path and long-path sound paths were established in the smoke test area, and the detection pulse sequence was obtained using an ultrasonic transmitter;

[0207] Two-path echo data were acquired using an ultrasound receiver, short-path, long-path, and detection pulse sequences.

[0208] Propagation time data is obtained based on dual path echo data, the actual propagation speed is calculated using the propagation time data, the path temperature nodes are obtained using temperature sensors, and the clean air reference propagation speed is obtained based on the path temperature nodes.

[0209] The temperature-compensated propagation change is obtained based on the actual propagation speed and the clean air reference propagation speed.

[0210] Amplitude attenuation data is obtained based on double path echo data, and frequency attenuation difference is obtained based on amplitude attenuation data.

[0211] Smoke feature identifiers are obtained by utilizing temperature-compensated propagation changes, frequency attenuation differences, and path temperature nodes. Smoke concentration detection is achieved based on these smoke feature identifiers and an alarm.

[0212] Specifically, the processor 10's implementation method for the above instructions can be found in [reference needed]. Figures 1 to 3 The descriptions of the relevant steps in the corresponding embodiments are not repeated here.

[0213] Furthermore, if the modules / units integrated in the electronic device 1 are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. The computer-readable storage medium can be volatile or non-volatile. For example, the computer-readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, or a read-only memory (ROM).

[0214] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor of an electronic device, can perform the following:

[0215] The system receives a smoke concentration detection command and, based on the command, identifies the smoke concentration detection system and the smoke detection area. The smoke concentration detection system includes an ultrasonic transmitter, an ultrasonic receiver, a temperature sensor, and an alarm.

[0216] Short-path and long-path sound paths were established in the smoke test area, and the detection pulse sequence was obtained using an ultrasonic transmitter;

[0217] Two-path echo data were acquired using an ultrasound receiver, short-path, long-path, and detection pulse sequences.

[0218] Propagation time data is obtained based on dual path echo data, the actual propagation speed is calculated using the propagation time data, the path temperature nodes are obtained using temperature sensors, and the clean air reference propagation speed is obtained based on the path temperature nodes.

[0219] The temperature-compensated propagation change is obtained based on the actual propagation speed and the clean air reference propagation speed.

[0220] Amplitude attenuation data is obtained based on double path echo data, and frequency attenuation difference is obtained based on amplitude attenuation data.

[0221] Smoke feature identifiers are obtained by utilizing temperature-compensated propagation changes, frequency attenuation differences, and path temperature nodes. Smoke concentration detection is achieved based on these smoke feature identifiers and an alarm.

[0222] In the embodiments provided by this invention, it should be understood that the disclosed devices, systems, and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative, and actual implementations may have other classification methods.

[0223] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0224] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in the form of hardware plus software functional modules.

[0225] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0226] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions 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 solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for detecting smoke concentration based on temperature compensation, characterized in that, The method includes: The system receives a smoke concentration detection command and, based on the command, identifies the smoke concentration detection system and the smoke detection area. The smoke concentration detection system includes an ultrasonic transmitter, an ultrasonic receiver, a temperature sensor, and an alarm. Short-path and long-path sound paths were established in the smoke test area, and the detection pulse sequence was obtained using an ultrasonic transmitter; Two-path echo data were acquired using an ultrasound receiver, short-path, long-path, and detection pulse sequences. Propagation time data is obtained based on dual path echo data, the actual propagation speed is calculated using the propagation time data, the path temperature nodes are obtained using temperature sensors, and the clean air reference propagation speed is obtained based on the path temperature nodes. The temperature-compensated propagation change is obtained based on the actual propagation speed and the clean air reference propagation speed. Amplitude attenuation data is obtained based on double path echo data, and frequency attenuation difference is obtained based on amplitude attenuation data. Smoke feature identifiers are obtained by utilizing temperature-compensated propagation changes, frequency attenuation differences, and path temperature nodes. Smoke concentration detection is achieved based on these smoke feature identifiers and an alarm.

2. The smoke concentration detection method based on temperature compensation as described in claim 1, characterized in that, The method of acquiring the detection pulse sequence using an ultrasonic transmitter includes: The pulse configuration node is obtained using an ultrasonic transmitter. The pulse configuration node includes: a first frequency, a second frequency, a pulse transmission duration, a pulse drive amplitude, and a pulse interval. Obtain the start time of the detection cycle and use the start time of the detection cycle as the first launch time; A first frequency detection pulse is generated based on the first frequency, pulse transmission duration, and pulse drive amplitude, and the first frequency detection pulse and the first transmission time are associated to obtain the first pulse identifier; A second frequency detection pulse is generated based on the second frequency, pulse transmission duration, and pulse drive amplitude. The second transmission time is obtained based on the first transmission time and pulse interval. The second pulse identifier is obtained by associating the second frequency detection pulse with the second transmission time. A verification detection pulse is generated based on the first frequency, pulse transmission duration, and pulse drive amplitude. The verification transmission time is obtained based on the second transmission time and pulse interval. The verification detection pulse and the verification transmission time are correlated to obtain the verification pulse identifier. The first pulse identifier, the second pulse identifier, and the verification pulse identifier are sorted in chronological order to obtain the detection pulse sequence.

3. The smoke concentration detection method based on temperature compensation as described in claim 2, characterized in that, The method of acquiring dual-path echo data using an ultrasonic receiver, short-path, long-path, and detection pulse sequence includes: Obtain the short path length, long path length, short echo time window, and long echo time window; The short-range echo set is obtained by using an ultrasonic receiver to receive the echo signal formed after the detection pulse sequence has propagated through a short acoustic path within a short echo time window. Based on the short-range echo set, the short-range echoes corresponding to the first pulse identifier, the second pulse identifier, and the verification pulse identifier are confirmed respectively, and the first short-range identifier echo, the second short-range identifier echo, and the short-range verification echo are obtained. A long-range echo set is obtained by using an ultrasonic receiver to receive the echo signal formed after the detection pulse sequence has propagated over a long acoustic path within a long echo time window. Based on the long-range echo set, the long-range echoes corresponding to the first pulse identifier, the second pulse identifier, and the verification pulse identifier are confirmed respectively, and the first long-range identifier echo, the second long-range identifier echo, and the long-range verification echo are obtained. By associating the first short-range identifier echo, the first long-range identifier echo, the short path length, and the long path length, the first double-path echo node is obtained. By associating the second short-path marker echo, the second long-path marker echo, the short path length, and the long path length, the second double-path echo node is obtained. By correlating the short-range core echo, the long-range core echo, the short path length, and the long path length, the core double-path echo node is obtained; The first two-path echo node, the second two-path echo node, and the verification two-path echo node are summarized to obtain the two-path echo data.

4. The smoke concentration detection method based on temperature compensation as described in claim 3, characterized in that, The acquisition of propagation time data based on two-path echo data includes: Envelope extraction is performed on the first short-range identifier echo to obtain the short-range envelope time series. The short-range envelope time series includes multiple short-range envelope points, and each short-range envelope point includes: short-range envelope amplitude and short-range sampling time. Obtain the main short-range peak value, multiply it by the main short-range peak value and the preset arrival ratio to obtain the main short-range arrival peak value; Within the short-range envelope time series, the short-range sampling time corresponding to the first short-range envelope amplitude that is greater than the peak value of the main short-range arrival is identified as the short-range time. The long-range time is obtained based on the first long-range identifier echo and the arrival ratio; By associating the first pulse identifier, short-range time, long-range time, short-range sound path length, and long-range sound path length, the first propagation time node is obtained; The short-range verification time and the long-range verification time are obtained from the short-range verification echo and the long-range verification echo. By associating the verification pulse identifier, verification short-range time, verification long-range time, short sound path length, and long sound path length, the verification propagation time node is obtained; By summarizing the first propagation time point and the verification propagation time point, propagation time data is obtained.

5. The smoke concentration detection method based on temperature compensation as described in claim 4, characterized in that, The calculation of the actual propagation speed using propagation time data includes: Calculate the time interval between the short-range time and the long-range time to obtain the main measurement time interval; The absolute difference between the long and short sound paths is calculated to obtain the sound path difference; The ratio of the sound path difference to the main measurement time interval is calculated to obtain the main measurement propagation velocity; The verification propagation speed is calculated based on the short-range verification time, the long-range verification time, and the sound path difference. The absolute difference between the primary propagation velocity and the secondary propagation velocity is calculated to obtain the periodic velocity deviation; When the periodic velocity deviation is less than or equal to the preset velocity deviation threshold, the average of the main propagation velocity and the verification propagation velocity is calculated to obtain the actual propagation velocity.

6. The smoke concentration detection method based on temperature compensation as described in claim 5, characterized in that, The step of acquiring path temperature nodes using temperature sensors and obtaining clean air reference propagation velocity based on path temperature nodes includes: Temperature sensors were used to measure the temperature of the ultrasonic transmitter, the ultrasonic receiver, and the temperature of the smoke test area to obtain the transmitter temperature, receiver temperature, and cavity wall temperature. Calculate the average temperature at the transmitting end and the receiving end to obtain the path average temperature; The absolute difference between the temperature at the transmitting end and the temperature at the receiving end is calculated to obtain the path gradient temperature. Obtain the historical average temperature of the path, calculate the difference between the path average temperature and the historical average temperature of the path, and obtain the periodic temperature change, where the path average temperature is the minuend. By associating the average temperature along the path, the gradient temperature along the path, the periodic temperature change, and the cavity wall temperature, the path temperature nodes are obtained. The initial reference propagation velocity is retrieved from the pre-built clean air sound velocity table using the path average temperature, the gradient correction amount is retrieved from the pre-built temperature gradient correction table using the path gradient temperature, and the thermal hysteresis correction amount is retrieved from the pre-built thermal hysteresis correction table using the periodic temperature change and the cavity wall temperature. The clean air reference propagation velocity is obtained by summing the initial reference propagation velocity, the gradient correction, and the thermal hysteresis correction.

7. The smoke concentration detection method based on temperature compensation as described in claim 6, characterized in that, The process of obtaining amplitude attenuation data based on double path echo data and obtaining frequency attenuation difference based on amplitude attenuation data includes: The first frequency short-range amplitude is obtained based on the first short-range identifier echo, and the first frequency long-range amplitude is obtained based on the first long-range identifier echo. The second frequency short-range amplitude is obtained based on the second short-range identifier echo, and the second frequency long-range amplitude is obtained based on the second long-range identifier echo; By correlating the short-range amplitude of the first frequency, the long-range amplitude of the first frequency, the short-range amplitude of the second frequency, and the long-range amplitude of the second frequency, amplitude attenuation data is obtained. The difference between the short-range amplitude of the first frequency and the long-range amplitude of the first frequency is calculated to obtain the sound path attenuation of the first frequency, where the short-range amplitude of the first frequency is the minuend. The difference between the short-range amplitude of the second frequency and the long-range amplitude of the second frequency is calculated to obtain the sound path attenuation of the second frequency, where the short-range amplitude of the second frequency is the minuend. Obtain clean air reference nodes, wherein the clean air reference nodes include: a first frequency reference attenuation and a second frequency reference attenuation; The frequency attenuation difference is calculated using the sound path attenuation at the first frequency, the sound path attenuation at the second frequency, the reference attenuation at the first frequency, and the reference attenuation at the second frequency. The calculation formula is as follows: ； in, This indicates the difference in frequency attenuation. This indicates the sound path attenuation at the second frequency. This represents the sound path attenuation at the first frequency. This indicates the attenuation of the second frequency reference. This indicates the attenuation of the first frequency reference.

8. The smoke concentration detection method based on temperature compensation as described in claim 7, characterized in that, The method of obtaining smoke feature identifiers using temperature-compensated propagation changes, frequency attenuation differences, and path temperature nodes includes: If the absolute value of the periodic temperature change is not greater than the preset temperature stability threshold, the absolute value of the temperature compensation propagation change is greater than the preset sound speed anomaly threshold, and the frequency attenuation difference is greater than the preset attenuation anomaly threshold, then the smoke feature is marked as valid. Otherwise, the smoke feature identifier will be marked as invalid.

9. The smoke concentration detection method based on temperature compensation as described in claim 8, characterized in that, The method of detecting smoke concentration based on smoke feature identifiers and alarms includes: When the smoke feature is identified as valid, the concentration lookup table node is obtained by associating the temperature compensation propagation change, frequency attenuation difference, and path temperature node. Use the concentration lookup table node to find the smoke concentration value in the pre-built smoke concentration calibration table; The smoke concentration value is compared with the preset alarm threshold to obtain the concentration alarm result, where the concentration alarm result is either the alarm threshold has been reached or the alarm threshold has not been reached. Once the concentration alarm result is confirmed to have reached the alarm threshold, the alarm device will output an alarm message. When the smoke feature identifier is invalid, a verification detection command is generated, and the process returns to the step of obtaining the detection pulse sequence using the ultrasonic transmitter based on the verification detection command.

10. A smoke concentration detection system based on temperature compensation, characterized in that, The system includes: The instruction response module is used to receive smoke concentration detection instructions and, based on the smoke concentration detection instructions, identify the smoke concentration detection system and the smoke detection area. The smoke concentration detection system includes an ultrasonic transmitter, an ultrasonic receiver, a temperature sensor, and an alarm. The echo data acquisition module is used to establish short-path and long-path sound in the smoke test area and to acquire the detection pulse sequence using an ultrasonic transmitter; Two-path echo data were acquired using an ultrasound receiver, short-path, long-path, and detection pulse sequences. The temperature compensation module is used to acquire propagation time data based on dual path echo data, calculate the actual propagation speed using the propagation time data, acquire path temperature nodes using temperature sensors, and acquire clean air reference propagation speed based on the path temperature nodes. The temperature-compensated propagation change is obtained based on the actual propagation speed and the clean air reference propagation speed. The smoke feature fusion module is used to obtain amplitude attenuation data based on double path echo data, and to obtain frequency attenuation difference based on amplitude attenuation data. Smoke feature identifiers are obtained by utilizing temperature-compensated propagation changes, frequency attenuation differences, and path temperature nodes. Smoke concentration detection is achieved based on these smoke feature identifiers and an alarm.

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