Linkage test method of security camera and alarm for cultural relics and ancient buildings

Abstract

The application provides a linkage test method for a security camera and an alarm of cultural relics and ancient buildings, relates to the technical field of linkage test of cultural relics and ancient buildings, and comprises the following steps: selecting a test area, collecting and recording initial state parameters of a communication link and initial state parameters of a camera field of view; simulating a fire environment; triggering a test event in a time sequence inversion mode; after an intrusion simulation signal is triggered, continuously collecting real-time error code rates of the communication link, linkage time delays between the alarm and the camera, and image definition data of a camera video stream; according to the collected real-time error code rates, linkage time delays and image definition data, calculating a linkage reliability index, comparing the linkage reliability index with a preset threshold, and determining whether the linkage test is qualified. The application solves the problems of single scene, ideal environment and subjective determination of the prior art by constructing an extreme test scene of fire and intrusion combination and quantitatively evaluating linkage performance.

Description

Technical Field

[0001] This invention relates to the field of linkage testing technology for cultural relics and ancient buildings, specifically to a linkage testing method for security cameras and alarms used in cultural relics and ancient buildings. Background Technology

[0002] Currently, existing technologies for testing the linkage between cameras and alarms in security systems for cultural relics and ancient buildings typically employ a single-scenario functional verification method. Testers simulate intrusion to trigger the alarm, then observe whether the camera can normally receive the alarm signal and start recording, thus determining if the linkage function is working properly. This type of testing is usually conducted under ideal environmental conditions with no interference and a healthy communication link. It focuses on verifying the electrical continuity and basic logic response of the security system. The testing process is simple and convenient, and it is widely used in the daily inspection and acceptance of various security systems.

[0003] However, existing testing methods have the following technical problems:

[0004] First, the test scenario is too simplistic, simulating only intrusion events and failing to consider the combined risks of fire and intrusion that may occur in real disasters affecting cultural relics and ancient buildings, especially the reversed sequence of "fire first, intrusion later." Second, the test environment is too idealistic, failing to simulate the physical degradation of communication links caused by high temperatures during fires (such as a surge in bit error rate due to increased cable impedance) and the visual obstruction of the camera's field of view by smoke, resulting in test results that cannot reflect the system's true linkage reliability under extreme conditions. Finally, existing test methods lack quantitative evaluation indicators for linkage performance, making it impossible to quantitatively determine the system reliability under the coupled effects of multiple factors such as communication link degradation, increased linkage latency, and image information loss, and also making it difficult to pinpoint the cause of failure and generate optimization suggestions. Summary of the Invention

[0005] To address the problems in related technologies, this invention provides a method for testing the linkage between security cameras and alarms used in cultural relics and ancient buildings.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] The method for testing the linkage between security cameras and alarms used in cultural relics and ancient buildings includes the following steps:

[0008] Step S1: Select the test area, collect and record the initial state parameters of the communication link and the initial state parameters of the camera's field of view;

[0009] Step S2: Simulate a fire environment, including applying controlled physical degradation to the communication link to simulate high temperature damage to the cable, and applying controlled visual obstruction to the camera's field of view to simulate smoke obstruction.

[0010] Step S3: Trigger the test event in reverse order, that is, first start the simulation of the fire environment, and then trigger the intrusion simulation signal after the fire environment simulation reaches the preset conditions;

[0011] Step S4: After the intrusion simulation signal is triggered, continuously collect the real-time bit error rate of the communication link, the linkage delay between the alarm and the camera, and the image clarity data of the camera video stream;

[0012] Step S5: Calculate the linkage reliability index based on the collected real-time bit error rate, linkage delay, and image clarity data, and compare the linkage reliability index with a preset threshold to determine whether the linkage test is qualified.

[0013] Optionally, in step S2, applying controllable physical degradation to the communication link specifically includes:

[0014] A controllable line impedance simulator is connected in series in the communication link between the alarm and the camera, and the link impedance Z is adjusted from its initial value. Increase to the target degradation value ;

[0015] The target degradation value Calculated using the following formula:

[0016]

[0017] In the formula, This represents the degraded link impedance. Indicates the initial link impedance. The coefficient of thermal degradation of the material is a dimensionless constant, and its value ranges from 1 to 2. ; To simulate fire temperature, The initial ambient temperature, The rated maximum withstand temperature for the cable insulation layer.

[0018] Optionally, in step S2, applying controllable visual occlusion to the camera's field of view specifically includes:

[0019] A controllable water mist curtain generator is deployed in front of the camera lens. By adjusting the water mist concentration, the smoke transmittance in the camera's field of view is adjusted. Reduce to the preset target value;

[0020] The smoke transmittance It is a dimensionless parameter, and its value range is: This indicates the percentage of effective image information that the camera can obtain through smoke.

[0021] Optionally, triggering the test event in a time-reversed manner as described in step S3 specifically includes:

[0022] At the preset first time point, the physical degradation simulation of the communication link and the visual occlusion simulation of the camera's field of view are initiated;

[0023] After the first preset time interval following the activation of the physical degradation simulation and visual occlusion simulation, the simulated fire source heat radiation device is activated to raise the temperature of the test area to the preset simulated fire temperature.

[0024] After a second preset time interval following the activation of the simulated fire source heat radiation device, an intrusion simulation signal is triggered, activating the detection function of the alarm.

[0025] After the intrusion simulation signal is triggered, the linkage response is continuously monitored within a preset time period.

[0026] Optionally, in step S4, the collected data includes at least the alarm trigger time, the time when the camera receives the alarm signal, the time when the camera starts recording, the real-time bit error rate of the communication link, and the effective frame rate of the camera video stream.

[0027] Optionally, in step S5, the linkage reliability index is calculated using the following formula:

[0028]

[0029] In the formula, This represents the linkage reliability index, with a value range of [value range missing]. , This is the scene normalization coefficient, and its value range is... , This is the bit error rate sensitivity coefficient, with a value range of [value range missing]. , This represents the maximum bit error rate monitored during the test. The maximum allowable bit error rate threshold for the system design, For actual linkage delay, This represents the maximum allowable linkage delay threshold for the system. Image information loss rate, The threshold for the maximum allowable image information loss rate.

[0030] Optionally, the image information loss rate Calculated using the following formula:

[0031]

[0032] In the formula, Indicates the video number grayscale gradient energy of a frame Image sharpness threshold, This is an indicator function. It takes the value 1 when the condition in parentheses is true, and 0 otherwise. N is the total number of frames within the test duration.

[0033] Optionally, in step S5, the linkage reliability index is compared with a preset threshold to determine whether the linkage test is qualified, specifically including:

[0034] like If the test point passes the test under simulated fire conditions, its linkage reliability is deemed acceptable.

[0035] like If the result is not satisfactory, optimization suggestions will be generated.

[0036] in, The preset threshold for reliable linkage is defined, and its value range is [value range missing]. .

[0037] Optionally, the generated optimization suggestions specifically include:

[0038] when Greater than the first preset threshold, and When the value is less than the second preset threshold, a suggestion is generated to increase the physical redundancy of the communication link or replace the high-temperature resistant cable.

[0039] when When the value exceeds the third preset threshold, a suggestion is generated to optimize the handshake protocol between the alarm and the camera or to use a near-field communication hardwire direct connection.

[0040] when When the value exceeds the fourth preset threshold, a suggestion is generated to deploy an edge image enhancement module at the camera end or to add auxiliary lighting in the smoke area.

[0041] Beneficial effects:

[0042] 1. Compared with the prior art, the present invention achieves significant improvements in the following four aspects through the synergistic effect of five steps:

[0043] First, the realism of the scenarios is improved (from a single ideal environment to a complex extreme environment). Specifically, existing technologies only test under ideal conditions where the communication link is intact and the field of vision is clear, which cannot reflect the harsh conditions in real fire scenarios, such as high temperatures causing cable degradation and smoke obstructing the view. This invention, through controllable physical degradation (simulating cable insulation melting and signal attenuation) and controllable visual obstruction (simulating smoke obstruction), reproduces the extreme environment of "communication degradation + visual obstruction" in the test, making the test scenario closer to a real disaster.

[0044] Second, the testing timing has been improved (from "intrusion first, then linkage" to "fire first, then intrusion"). Specifically, existing tests use a linear timing sequence of "intrusion first, then linkage," which cannot cover the real-world risk scenario of malicious individuals creating chaos through arson before intruding. This invention reverses the timing to make the test event sequence consistent with the real disaster event sequence, thereby evaluating the reliability of the security system's linkage in response to subsequent intrusions under adverse conditions such as a fire environment already formed, link degradation, and obstructed visibility.

[0045] Third, the comprehensiveness of the evaluation dimensions is improved (from binary results to three-dimensional quantitative monitoring). Specifically, existing technologies only collect a binary result of "whether recording was performed," which cannot reveal the specific reasons for linkage failure. This invention simultaneously collects three types of key parameters: real-time bit error rate (reflecting signal transmission quality), linkage delay (reflecting response speed), and image clarity (reflecting acquisition effectiveness), realizing multi-dimensional quantitative monitoring of the linkage process and locating the failure link.

[0046] Fourth, the objectivity of the judgment is improved (upgrading from manual subjective review to automated quantitative judgment). Specifically, existing technologies rely on manual review of video recordings to determine whether an alarm has been triggered, resulting in subjective and unrepeatable results. This invention calculates a linkage reliability index, integrating three heterogeneous dimensions—bit error rate, latency, and resolution—into a unified quantitative indicator, and automatically compares it with a preset threshold to achieve automated judgment of test results, avoiding human subjectivity.

[0047] 2. Other beneficial effects or advantages of the present invention will be described in detail in the specific embodiments. Attached Figure Description

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

[0049] in:

[0050] Figure 1 This is a flowchart illustrating the steps of a linkage testing method for security cameras and alarms used in cultural relics and ancient buildings, provided by an exemplary embodiment of the present invention. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0052] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0053] In addition, the terms "comprising" and "having" and any variations thereof mentioned in the description of the present invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes other unlisted steps or units, or optionally further includes other steps or units inherent to these processes, methods, products or devices. Among them, it should also be noted that in the embodiments of the present invention, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present invention should not be construed as more preferred or more advantageous than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific manner.

[0054] To facilitate a clearer and more accurate understanding of the technical solutions of the present invention by relevant technical personnel, the following will first provide a more detailed description of the existing related technologies and the technical problems they have.

[0055] Currently, for the linkage test of cameras and alarms in the security and protection system of cultural relics ancient buildings, the existing technology usually adopts a functional verification method in a single scenario.

[0056] Taking the security system test of a certain temple hall as an example, the tester first installs an infrared microwave dual-technology detector in the hall and installs a high-definition network camera above the main entrance of the hall. During the test, the tester walks through the detection area of the detector to trigger an alarm signal, which is transmitted to the backend platform through a wired RS-485 bus. The platform then联动 the camera to start recording and generates an alarm record. The tester determines whether the linkage function is normal by checking whether the video file contains the picture at the alarm moment and whether the video duration meets the preset value (such as 30 seconds). If the video is complete and contains the pictures before and after the alarm trigger, the linkage test is determined to be qualified. Such tests are usually carried out during the day without interference, with the communication line intact and the camera's field of view clear. The test environment is ideal, focusing on verifying the electrical connection and basic logical response of the security system, and the operation process is standardized, which is widely applicable to the daily inspection and project acceptance links of various security systems.

[0057] However, the above testing methods have revealed a series of technical defects in practical applications, which will be explained in detail below in conjunction with real risk scenarios of cultural relics and ancient buildings.

[0058] Taking a certain ancient wooden temple as an example, security records show that the temple experienced an arson incident at night. Malicious individuals ignited miscellaneous items piled up in the southeast corner of the main hall and then sneaked in to steal. In such real-world incidents, the intrusion occurred after the fire had spread, a typical "fire first, intrusion later" reversed sequence scenario. However, existing testing methods only simulate a single intrusion event, with the testing sequence being "alarm triggered first, recording started later," never addressing the testing logic of triggering an intrusion after a fire has already occurred. When a fire breaks out, smoke has already filled the main hall, and the high temperature softens the insulation of the security circuitry. If an intrusion alarm is triggered at this point, whether the system can still reliably function is something existing testing methods cannot provide any evaluation basis for.

[0059] Meanwhile, existing tests are typically conducted under conditions where the communication link is intact and the camera has a clear field of view. Taking the aforementioned ancient temple as an example, let's assume its security system uses wired communication, with cables laid along the wooden beams. In a real fire scenario, the temperature around the cables can reach over 150°C, far exceeding the rated operating temperature of 70°C for ordinary PVC cables. This high temperature causes the cable insulation to melt, causing the cable impedance to rise sharply from the normal 50Ω to over 200Ω, resulting in severe signal attenuation and a bit error rate increasing from 10⁻⁻⁻⁶. 6 The signal intensity surged to the 10⁻² level, causing packet loss or severe delays in alarm signal transmission. Simultaneously, the hall was filled with dense smoke, reducing the camera's field of view to less than 20%, resulting in an almost entirely white video feed, making it impossible to identify any intruders. However, existing testing methods have never incorporated these physical degradation conditions; the "linkage qualified" conclusion in the test report only reflects the functional state under ideal conditions and cannot characterize the system's true reliability under high-temperature fire and smoke-covered conditions.

[0060] Furthermore, the current testing criteria only consider whether the recording includes footage from the moment the alarm was triggered, which is a binary qualitative judgment. When system linkage fails, testers cannot distinguish whether the failure is due to a high error rate in the communication link causing the alarm signal to fail to arrive, excessive linkage delay causing the recording to miss crucial footage, or smoke obscuring the video image information, rendering it unusable. For example, in a linkage test at a museum, although the recording file was generated, the image clarity was insufficient due to smog, making it impossible to confirm whether someone had intruded into the alarm area. The current testing method still judged this linkage as qualified, even though the location was actually ineffective for security monitoring due to image information loss. Because of the lack of multi-dimensional quantitative indicators such as error rate, linkage delay, and image information loss rate, the test results cannot provide targeted improvement directions for system optimization.

[0061] In summary, existing testing methods have significant shortcomings in terms of test scenario coverage, environmental condition simulation, and performance quantification, and cannot meet the reliability verification requirements of security linkage for cultural relics and ancient buildings under complex risk scenarios.

[0062] In view of this, the present invention provides a novel solution, namely, a method for testing the linkage between security cameras and alarms used in cultural relics and ancient buildings. The technical concept of this invention lies in breaking away from the linear thinking of traditional security testing—"single scene, ideal environment, binary judgment"—and shifting towards a systematic testing paradigm of "multi-factor coupling, time sequence reversal, and quantitative evaluation." Specifically, this invention first constructs a composite test environment that closely approximates real disaster conditions by simulating the physical degradation of communication links caused by high temperatures during a fire (such as increased impedance and a surge in bit error rate) and the visual obstruction of the camera's field of view caused by smoke (such as reduced transmittance). Then, it employs a "fire first, theft later" time-reversed triggering mechanism to reproduce the real risk scenario of malicious individuals using arson to create chaos and then intruding. Based on this, by collecting multi-dimensional characteristic parameters such as bit error rate, linkage latency, and image information loss rate, it constructs a linkage reliability quantitative index system that integrates exponential decay and linear degradation models, achieving a leap from qualitative judgment of "whether linkage occurs" to quantitative assessment of "how high the linkage reliability is." Finally, based on threshold comparisons of the quantitative indicators, it automatically locates the failure points and generates differentiated optimization suggestions, forming a closed loop of "test-evaluation-optimization."

[0063] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0064] like Figure 1 As shown in the figure, this embodiment provides a method for testing the linkage between security cameras and alarms used in cultural relics and ancient buildings, including the following steps:

[0065] Step S1: Select the test area, collect and record the initial state parameters of the communication link and the initial state parameters of the camera's field of view;

[0066] Step S2: Simulate a fire environment, including applying controlled physical degradation to the communication link to simulate high temperature damage to the cable, and applying controlled visual obstruction to the camera's field of view to simulate smoke obstruction.

[0067] Step S3: Trigger the test event in reverse order, that is, first start the simulation of the fire environment, and then trigger the intrusion simulation signal after the fire environment simulation reaches the preset conditions;

[0068] Step S4: After the intrusion simulation signal is triggered, continuously collect the real-time bit error rate of the communication link, the linkage delay between the alarm and the camera, and the image clarity data of the camera video stream;

[0069] Step S5: Calculate the linkage reliability index based on the collected real-time bit error rate, linkage delay, and image clarity data, and compare the linkage reliability index with a preset threshold to determine whether the linkage test is qualified.

[0070] Through the above technical solution, firstly, step S1 of the present invention, by collecting initial state parameters, can provide a comparative benchmark for the physical degradation and visual occlusion applied in subsequent steps, thereby making the quantitative evaluation of the test results comparable. Specifically, parameters such as the initial signal-to-noise ratio, initial bit error rate, and initial transmission delay of the communication link, as well as the initial image sharpness parameters of the camera's field of view, together constitute the performance baseline of the system under ideal operating conditions, providing the necessary normalized benchmark for calculating the linkage reliability index in subsequent steps.

[0071] Secondly, in existing related technologies, traditional tests are only conducted under conditions where the communication link is intact and the field of view is clear, which cannot reflect the harsh physical conditions faced by the security systems of cultural relics and ancient buildings in real fire scenarios. However, in step S2 of this invention, a close approximation of the real disaster environment can be achieved through two aspects of controllable simulation. Specifically, firstly, by applying controllable physical degradation, the physical process of cable insulation melting, impedance increase, and signal attenuation caused by the high temperature of a fire is simulated, enabling the test to evaluate the signal transmission reliability of the communication link under degradation conditions; secondly, by applying controllable visual occlusion, the occlusion effect of fire smoke on camera imaging is simulated, enabling the test to evaluate the effectiveness of image acquisition by the camera under limited field of view conditions.

[0072] Third, existing testing methods employ a linear time sequence of "intrusion first, then linkage," which cannot cover scenarios where malicious actors create chaos through arson before intruding. In contrast, step S3 of this invention reverses the time sequence, ensuring the test event sequence aligns with the real disaster event sequence. This allows for the evaluation of the security system's reliability in responding to subsequent intrusion events under adverse conditions: a fire has already occurred, communication links have degraded, and visibility is obstructed. This ensures the test results accurately reflect the system's actual performance in complex risk scenarios, rather than merely reflecting its functional state under ideal time sequences.

[0073] Fourth, in existing related technologies, traditional testing only collects a binary result of "whether recording is performed," which cannot reveal the specific reasons for linkage failure. However, step S4 of this invention simultaneously collects three types of key parameters: real-time bit error rate (reflecting the signal transmission quality of the communication link under physical degradation conditions, and is a core indicator for judging whether the alarm signal is reliably delivered), linkage delay (reflecting the time difference from alarm triggering to recording start, and is a key indicator for judging linkage response speed), and image clarity data (reflecting the image acquisition quality of the camera under visual obstruction conditions, and is an important indicator for judging whether video information is usable), thereby enabling multi-dimensional quantitative monitoring of the linkage process.

[0074] Fifth, in existing related technologies, traditional testing relies solely on manual review of video recordings to determine if alarm footage is included, resulting in subjective and unquantifiable judgments. However, step S5 of this invention calculates a linkage reliability index, integrating parameters from three heterogeneous dimensions—bit error rate, latency, and image clarity—into a unified quantitative indicator, making the test results comparable and repeatable. By comparing with a preset threshold, automated judgment of the test results can be achieved, avoiding the subjectivity of manual judgment.

[0075] Overall, through the synergistic effect of the above five steps, this invention can not only effectively improve the realism of the scenario (expanding from a single intrusion scenario to a combined fire and intrusion scenario, and from an ideal environment to an extreme environment where communication degradation and visual obstruction coexist), but also effectively improve the rationality of the test sequence (adjusting the linear sequence of "intrusion first, then linkage" to the inverted sequence of "fire first, then theft," making the test event sequence consistent with the real risk event sequence), and effectively improve the completeness of the evaluation dimensions (expanding from a binary judgment of "whether recording is made" to three-dimensional quantitative monitoring of bit error rate, latency, and image clarity). In addition, it can also improve the objectivity of the judgment to a certain extent (from manual subjective review of recordings to automated judgment based on quantitative indicators and preset thresholds).

[0076] The technical solution of the present invention will be further described below with reference to an exemplary embodiment.

[0077] It should be noted that this embodiment uses the security system linkage test of the main hall of a certain wooden ancient temple as an example.

[0078] I. Test Subjects and Equipment Configuration

[0079] The test area was selected as the main hall of the ancient temple, where the following security equipment has been deployed:

[0080] Alarm device: Infrared microwave dual-technology detector, installed on the inside upper part of the main hall entrance, with a detection range of 12 meters, and connected to the back-end platform via RS-485 wired communication;

[0081] Camera: A 4-megapixel high-definition network camera, installed above the main entrance of the hall, sharing the same RS-485 bus with the alarm system for alarm signal transmission, while transmitting video streams via a separate network cable;

[0082] Communication link: RVVP 2×1.0 shielded twisted pair cable, approximately 80 meters in total length, laid along wooden beams, with PVC insulation and rated maximum withstand temperature. ;

[0083] Backend testing platform: An industrial control computer equipped with test management software, used to control test equipment, collect data, and perform linked reliability index calculations.

[0084] II. Test Procedures and Data Recording

[0085] Step S1: Initial state calibration.

[0086] Before the test begins, collect and record the following initial state parameters:

[0087] Initial link impedance (Use a multimeter to measure at the end of the cable);

[0088] Initial ambient temperature (Measurement is performed using a patch thermocouple attached to the surface of the cable).

[0089] Initial signal-to-noise ratio Initial bit error rate (This data was obtained by sending 10,000 test frames using a serial port debugging tool).

[0090] Initial image sharpness: Select a reference frame from the main entrance area of ​​the hall, and calculate the mean grayscale gradient energy as follows: Gray level / pixel (calculated using the Sobel operator).

[0091] Step S2: Simulate a fire environment.

[0092] S2.1: Simulation of physical degradation of communication links.

[0093] A controllable line impedance simulator is connected in series in the RS-485 communication link between the alarm and the camera. The simulated fire temperature is then set. (Simulating the temperature around the cable in the early stage of a fire), the material thermal degradation coefficient is taken as k=0.8 (the typical impedance growth coefficient of PVC cable at high temperature).

[0094] According to the formula Calculate the target degradation impedance:

[0095]

[0096] Adjust the output impedance of the impedance simulator to 128 Ω to simulate the impedance increase state of the cable in a high-temperature environment of 150 °C.

[0097] S2.2: Visual occlusion simulation of the camera's field of view.

[0098] Deploy a controllable water mist curtain generator 0.5 m in front of the camera lens. By adjusting the water mist concentration, set the smoke transmittance τ to 0.25, that is, only 25% of the image information can penetrate the smoke and reach the camera sensor. Use a transmissometer for on-site calibration and confirmation.

[0099] Step S3: Trigger test events with time sequence inversion.

[0100] Execute the test event sequence according to the time sequence setting:

[0101] The first time point Seconds, start the communication link impedance simulator (output impedance of 128 Ω) and the water mist curtain generator (transmittance of 0.25);

[0102] The first preset time interval Seconds later (i.e., t = 5 s), activate the simulated fire source heat radiation device, which consists of two groups of infrared heating plates and is placed 0.3 m below the cable laying path, so that the surface temperature of the cable rises from 22 °C to 150 °C within 30 s and remains stable;

[0103] The second preset time interval Seconds later (i.e., t = 10 s), trigger the intrusion simulation signal, activate the test mode of the alarm through the remote control, and simulate the intrusion of an intruder into the detection area;

[0104] The continuous monitoring duration Seconds, starting from the triggering of the intrusion signal, continuously monitor the linkage response within 30 s.

[0105] Step S4: Multi-dimensional data acquisition.

[0106] During the 30-s monitoring window after the triggering of the intrusion signal, the data synchronously collected through the back-end test platform can be referred to Table 1 below.

[0107] Table 1 Data table of the back-end test platform for synchronous acquisition

[0108]

[0109] Note: The method for calculating the bit error rate is to send 200 test frames per second within the monitoring window, count the proportion of error frames, and record the maximum value of 0.023.

[0110] Step S5: Calculation and determination of the linkage reliability index.

[0111] S5.1: Image information loss rate calculation.

[0112] Extract N=300 frames (30 seconds × 10fps nominal frame rate) from the video stream in the monitoring window, and calculate the grayscale gradient energy for each frame. Set image sharpness threshold Grayscale value per pixel (images with a grayscale value below this value cannot distinguish the outline of people).

[0113] According to statistics, among 300 frames, those that meet the requirements The frame rate is 57 frames per second.

[0114] According to the formula Calculate the image information loss rate: That is, 81% of the video frames could not provide effective image information due to smoke obscuring the images.

[0115] S5.2: Calculation of linkage reliability index.

[0116] Set the following system parameters:

[0117] Scene normalization coefficient (Given that this test point is located at the main entrance of the hall, it is given a higher weight), Bit Error Rate Sensitivity Coefficient (Reflecting the nonlinear impact of bit error rate on system reliability), the maximum allowable bit error rate threshold for the system. The system allows a maximum linkage delay threshold. Maximum allowable image information loss rate threshold (That is, at least 50% of the frames must remain identifiable).

[0118] Substitute the collected data into the formula: Calculations yielded ;

[0119] Because the domain of the linkage reliability index is And the calculation result is negative, so the actual value is taken as... .

[0120] S5.3: Conformity assessment and optimization suggestions.

[0121] Set the linkage reliability pass threshold ,because The test point was deemed to have failed the linkage test.

[0122] Failure location and optimization suggestions are generated based on the following judgment logic:

[0123] Communication link failure determination: (The first preset threshold is set to 1), and (The second preset threshold is set to 0.3). If the condition is met, the following suggestion is generated: increase the physical redundancy of the communication link or replace the high-temperature resistant cable (such as replacing the PVC cable with a fluoroplastic insulated cable with a temperature resistance of 150°C or higher).

[0124] Linkage delay determination (The third preset threshold is set to 0.8), and the latency item did not trigger the optimization suggestion;

[0125] Image loss determination: (The fourth preset threshold is set to 0.8). If the condition is met, the following suggestion is generated: Deploy an edge image enhancement module at the camera end or add auxiliary lighting in the smoke area (such as integrating a deep learning-based defogging algorithm at the front end of the camera or adding infrared fill lights around the detector).

[0126] III. Test Conclusions.

[0127] Test results show that, under simulated combined fire and intrusion risk scenarios, the linkage reliability index of this location is [missing information]. The error rate was far below the acceptable threshold of 0.75. Failure location analysis showed that excessive communication link bit error rate and excessive image information loss rate were the main causes of the failure. Based on the optimization recommendations, the cabling at this location will be upgraded and the camera will be enhanced. After the upgrades are completed, the site will be retested to verify the improvement effect.

[0128] In the above embodiments, it should be noted that,

[0129] First, regarding the target degradation value The calculation formula ( For this formula, it is based on the principle of the temperature resistance effect of conductor materials. For the overall link impedance composed of a metal conductor (cable core) and its insulation layer, the impedance value increases with increasing temperature. This phenomenon is due to the combined effect of the temperature coefficient of resistance of the metal conductor and the change of dielectric properties of the insulation material with temperature.

[0130] It can be decomposed into three levels: the first level is the reference impedance. The cable at the initial ambient temperature The inherent impedance, determined by the conductor resistivity, wire diameter, length, and dielectric properties of the insulation layer, serves as the benchmark for subsequent degradation calculations. The second level is the normalized temperature difference. The difference between the actual fire temperature and the initial temperature is normalized relative to the rated maximum withstand temperature of the cable insulation. This ratio reflects the degree of damage caused by thermal stress to the cable material. near When the ratio approaches 1, it indicates that the material is approaching its tolerance limit; when Exceed When the ratio is greater than 1, it indicates that the material enters the overload degradation region. The third level is the thermal degradation coefficient k: which characterizes the impedance growth amplitude of the cable material under unit thermal stress. The value range of k is 0 < k ≤ 1, and its specific value depends on the cable material: the k value of PVC insulated cables is relatively high (about 0.6 - 0.9), because its insulation layer softens significantly at high temperatures and the dielectric constant changes violently; the k value of fluoroplastic or silicone rubber insulated cables is relatively low (about 0.2 - 0.4), because of its excellent heat resistance and small impedance change with temperature.

[0131] It should be noted that in engineering practice, the change of cable impedance with temperature is not completely linear. However, within no more than twice the range, the linear approximation has sufficient engineering accuracy. This formula adopts a linear model, which is convenient for engineering implementation and parameter calibration, and can accurately reflect the core physical law that the impedance increases monotonically with temperature.

[0132] Second, for the calculation formula of the linkage reliability index ( ), it is based on the product model in reliability engineering. Its core assumption is that the overall reliability of the security linkage system is equal to the product of the reliabilities of each independent failure mode. When multiple factors jointly affect the system performance, the failure of any factor will lead to a decline in the overall function. Therefore, a multiplication structure is used to integrate the contributions of each factor.

[0133] For this formula, it includes:

[0134] The bit error rate factor ( ) adopts an exponential decay model, and its principle stems from the bit error rate threshold effect in communication systems. In digital communication, when the bit error rate is lower than a certain threshold, the channel coding and error correction mechanisms can effectively recover the original data, and the system performance is hardly affected; once the bit error rate exceeds the threshold, the error correction mechanism fails, and the data packet loss rate rises sharply, and the system performance deteriorates exponentially. The characteristic that the exponential function rapidly decays after x > 1 exactly describes this non-linear relationship. When , the factor value is . If is taken, the factor value is about 0.22, indicating that it has entered the severe failure region; when , the factor value is about 0.47, indicating partial degradation but still acceptable. The parameter is used to adjust the decay rate and can be calibrated according to the bit error tolerance characteristics of specific communication protocols (such as Modbus, CAN bus, RS-485).

[0135] The time delay factor ( The delay factor employs a linear attenuation model, based on the concept of time synchronization tolerance. Security linkage requires precise time alignment between alarm signals and video recordings; excessive delay can cause recordings to miss crucial moments. The delay factor is linear because the impact of delay on system reliability is continuous and gradual, without a sudden threshold. When the factor value is 1, it indicates ideal synchronization. When the factor value is 0, it means that the latency has reached the allowable limit, and the linkage is no longer meaningful.

[0136] Image loss factor ( The term also employs a linear decay model, based on the concept of video availability. Image information loss rate. It reflects the proportion of content in a video frame that can be recognized by humans or machines. When When all frames are identifiable, the factor value is 1; when When the factor value is 0, it indicates that the image loss has reached the allowable limit and the video can no longer provide valid evidence. A linear model is used because the impact of image sharpness degradation on recognition performance is continuous and gradual.

[0137] Scene normalization coefficient This is used to adjust the weights of different test points. Different areas of cultural relics and ancient buildings have different security importance (e.g., the main hall entrance has a higher weight than the side hall storage rooms). This allows the test results to reflect these differentiated reliability requirements, with a range of values. .

[0138] In reliability engineering, if a system consists of n independent modules connected in series, the system reliability is the product of the reliability of each module. In this invention, the bit error rate, latency, and image loss correspond to the performance degradation of the communication module, time synchronization module, and video acquisition module, respectively. These three are independent of each other (communication bit errors do not directly affect latency, and latency does not directly affect image quality). Therefore, the use of a multiplicative structure has a sound engineering theoretical basis.

[0139] Third, regarding image information loss rate The calculation formula ( In contrast, it is a gray-level gradient energy quantization method based on image sharpness. Its core principle is to use the sharpness of image edges to evaluate the quality of image information.

[0140] Image sharpness is essentially the visibility of details in an image, and details in digital images are represented by the spatial rate of change of grayscale values, i.e., the gradient. For each pixel in a video frame, its grayscale gradient is defined as the grayscale difference between that pixel and its neighboring pixels. The grayscale gradient energy of the entire frame... The formula is obtained by summing the gradient magnitudes of all pixels: ,in, For pixel grayscale values, and These represent the grayscale change rates in the horizontal and vertical directions, respectively. A sharp image has sharp edges, dramatic grayscale changes, and high gradient energy; a blurred image (such as one obscured by smoke or out of focus) has smooth edges, gradual grayscale changes, and low gradient energy. Therefore, grayscale gradient energy can be used as an effective quantitative indicator of image sharpness.

[0141] This formula uses a binarization method to classify video frames into two categories: "usable" and "unusable".

[0142] Set sharpness threshold This threshold can be calibrated experimentally: select a set of video frames under typical smoke concentrations, manually label whether the intruder's outline can be identified, and statistically determine the optimal gradient energy threshold for distinguishing between the two types of samples. Indicator function For each frame, if the gradient energy is not lower than a threshold, the frame is considered usable and recorded as 1; otherwise, it is recorded as 0. The results of all N frames are summed to obtain the number of usable frames. .

[0143] Meanwhile, the proportion of available frames to total frames This reflects the effective coverage of the video within the test duration. Subtracting this percentage from 1 yields the image information loss rate. This indicates the percentage of invalid video frames due to smoke obstruction.

[0144] This formula transforms the continuous video quality assessment problem into a discrete frame availability statistics problem, simplifying computational complexity while preserving the objectivity of the evaluation. Compared to subjective manual evaluation, this method is repeatable and quantifiable, making it suitable as a criterion for automated testing.

[0145] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for testing the linkage between security cameras and alarms used in cultural relics and ancient buildings, characterized in that, Includes the following steps: Step S1: Select the test area, collect and record the initial state parameters of the communication link and the initial state parameters of the camera's field of view; Step S2: Simulate a fire environment, including applying controlled physical degradation to the communication link to simulate high temperature damage to the cable, and applying controlled visual obstruction to the camera's field of view to simulate smoke obstruction. Step S3: Trigger the test event in reverse order, that is, first start the simulation of the fire environment, and then trigger the intrusion simulation signal after the fire environment simulation reaches the preset conditions; Step S4: After the intrusion simulation signal is triggered, continuously collect the real-time bit error rate of the communication link, the linkage delay between the alarm and the camera, and the image clarity data of the camera video stream; Step S5: Calculate the linkage reliability index based on the collected real-time bit error rate, linkage delay, and image clarity data, and compare the linkage reliability index with a preset threshold to determine whether the linkage test is qualified. In step S5, the linkage reliability index is calculated using the following formula: In the formula, This represents the linkage reliability index, with a value range of [value range missing]. , The scene normalization coefficient has a range of values. , This is the bit error rate sensitivity coefficient, with a value range of [value range missing]. , This represents the maximum bit error rate monitored during the test. The maximum allowable bit error rate threshold for the system design, For actual linkage delay, This represents the maximum allowable linkage delay threshold for the system. Image information loss rate, The threshold for the maximum allowable image information loss rate.

2. The method for testing the linkage between security cameras and alarms used in cultural relics and ancient buildings according to claim 1, characterized in that, In step S2, applying controllable physical degradation to the communication link specifically includes: A controllable line impedance simulator is connected in series in the communication link between the alarm and the camera, and the link impedance Z is adjusted from its initial value. Increase to the target degradation value ; The target degradation value Calculated using the following formula: In the formula, This represents the degraded link impedance. Indicates the initial link impedance. The coefficient of thermal degradation of the material is a dimensionless constant, and its value ranges from 1 to 2. ; To simulate fire temperature, The initial ambient temperature, The rated maximum withstand temperature for the cable insulation layer.

3. The method for testing the linkage between security cameras and alarms used in cultural relics and ancient buildings according to claim 1, characterized in that, In step S2, the controllable visual occlusion applied to the camera's field of view specifically includes: A controllable water mist curtain generator is deployed in front of the camera lens. By adjusting the water mist concentration, the smoke transmittance in the camera's field of view is adjusted. Reduce to the preset target value; The smoke transmittance It is a dimensionless parameter, and its value range is: This indicates the percentage of effective image information that the camera can obtain through smoke.

4. The method for testing the linkage between security cameras and alarms used in cultural relics and ancient buildings according to claim 1, characterized in that, The step S3, which involves triggering the test event in a time-reversed manner, specifically includes: At the preset first time point, the physical degradation simulation of the communication link and the visual occlusion simulation of the camera's field of view are initiated; After the first preset time interval following the activation of the physical degradation simulation and visual occlusion simulation, the simulated fire source heat radiation device is activated to raise the temperature of the test area to the preset simulated fire temperature. After a second preset time interval following the activation of the simulated fire source heat radiation device, an intrusion simulation signal is triggered, activating the detection function of the alarm. After the intrusion simulation signal is triggered, the linkage response is continuously monitored within a preset time period.

5. The method for testing the linkage between security cameras and alarms used in cultural relics and ancient buildings according to claim 1, characterized in that, In step S4, the collected data includes at least the alarm trigger time, the time when the camera receives the alarm signal, the time when the camera starts recording, the real-time bit error rate of the communication link, and the effective frame rate of the camera video stream.

6. The method for testing the linkage between security cameras and alarms used in cultural relics and ancient buildings according to claim 1, characterized in that, The image information loss rate Calculated using the following formula: In the formula, Indicates the video number grayscale gradient energy of a frame Image sharpness threshold, This is an indicator function. It takes the value 1 when the condition in parentheses is true, and 0 otherwise. N is the total number of frames within the test duration.

7. The method for testing the linkage between security cameras and alarms used in cultural relics and ancient buildings according to claim 1, characterized in that, In step S5, the linkage reliability index is compared with a preset threshold to determine whether the linkage test is qualified. This specifically includes: like If the test point passes the test under simulated fire conditions, its linkage reliability is deemed acceptable. like If the result is not satisfactory, optimization suggestions will be generated. in, The preset threshold for reliable linkage is defined, and its value range is [value range missing]. .

8. The method for testing the linkage between security cameras and alarms used in cultural relics and ancient buildings according to claim 7, characterized in that, The generated optimization suggestions specifically include: when Greater than the first preset threshold, and When the value is less than the second preset threshold, a suggestion is generated to increase the physical redundancy of the communication link or replace the high-temperature resistant cable. when When the value exceeds the third preset threshold, a suggestion is generated to optimize the handshake protocol between the alarm and the camera or to use a near-field communication hardwire direct connection. when When the value exceeds the fourth preset threshold, a suggestion is generated to deploy an edge image enhancement module at the camera end or to add auxiliary lighting in the smoke area.

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