Monitoring device, its control method, and computer-readable storage medium

Abstract

The present application provides a monitoring device, a control method thereof, and a computer-readable storage medium, relating to the technical field of monitoring. The above monitoring device includes a first PIR sensor, a second PIR sensor, and a processor; there is an overlapping area between a first detection area corresponding to the first PIR sensor and a second detection area corresponding to the second PIR sensor; the processor is configured to: when determining that a moving target appears in the first detection area or the second detection area, based on first PIR data collected by the first PIR sensor and second PIR data collected by the second PIR sensor, detect whether the moving target enters the overlapping area within a preset time period; if so, determine whether the motion trajectory of the moving target meets an alarm trigger condition according to the above first PIR data and second PIR data; if it meets, output an alarm message. The technical solution provided by the present application can effectively avoid false alarms of the monitoring device and improve the detection accuracy of the monitoring device.

Description

Technical Field

[0001] This application relates to the field of monitoring technologies, and in particular, to a monitoring device, a control method thereof, and a computer-readable storage medium. Background Art

[0002] A pyroelectric infrared (PIR) sensor is a sensor commonly used in the security field. It can detect based on the infrared radiation emitted by an object, and is particularly suitable for detecting the movement of warm objects such as humans or animals.

[0003] However, since the PIR sensor is easily interfered by environmental temperature difference fluctuations, there are many false alarms in the actual application of the monitoring device, which affects the detection accuracy of the monitoring device. Summary of the Invention

[0004] This application provides a monitoring device, a control method thereof, and a computer-readable storage medium, which can effectively avoid false alarms of the monitoring device and improve the detection accuracy of the monitoring device.

[0005] In a first aspect, this application provides a monitoring device, which includes a first PIR sensor, a second PIR sensor, and a processor; there is an overlapping area between a first detection area corresponding to the first PIR sensor and a second detection area corresponding to the second PIR sensor; the processor is configured to:

[0006] Determine that a moving target appears in the first detection area or the second detection area;

[0007] Based on the first PIR data collected by the first PIR sensor and the second PIR data collected by the second PIR sensor, detect whether the moving target enters the overlapping area within a preset time period;

[0008] When it is detected that the moving target enters the overlapping area, determine whether the movement trajectory of the moving target meets the alarm trigger condition according to the first PIR data and the second PIR data;

[0009] If the movement trajectory meets the alarm trigger condition, output an alarm message.

[0010] In some embodiments, the processor is specifically configured to:

[0011] Obtain the first PIR data and the second PIR data;

[0012] Perform downsampling on the first PIR data to obtain a first PIR signal, and perform downsampling on the second PIR data to obtain a second PIR signal;

[0013] When the first signal change rate of the first PIR signal at two adjacent sampling time points is greater than a preset change threshold, it is determined that a moving target appears in the first detection area;

[0014] When the second signal change rate of the second PIR signal at two adjacent sampling time points is greater than the change threshold, it is determined that a moving target appears in the second detection area.

[0015] In some embodiments, the above-mentioned processor is specifically configured to:

[0016] Determine the differential signal corresponding to the first PIR signal and the second PIR signal within a preset duration;

[0017] Determine whether the amplitude of the above differential signal at the sampling time point t is less than a first threshold;

[0018] If the amplitude of the above differential signal at the sampling time point t is less than the first threshold, determine whether the third signal change rate of the above differential signal at the sampling time point t compared to the sampling time point t-1 is greater than a second threshold;

[0019] When the above third signal change rate is greater than the second threshold, it is determined that the above moving target enters the overlapping area.

[0020] In some embodiments, the above-mentioned processor is specifically configured to:

[0021] Determine whether the current detection environment is stable according to the change conditions of the first PIR signal and the second PIR signal;

[0022] If the current detection environment is stable, update the above first threshold and / or second threshold.

[0023] In some embodiments, the above-mentioned processor is specifically configured to:

[0024] According to a preset sampling time window, respectively obtain at least one of the following signal characteristics: the first PIR signal, the second PIR signal, the differential signal, the first signal change rate, the second signal change rate, the third signal change rate; the above signal characteristics include variance and peak-to-peak value;

[0025] Update the above first threshold and / or second threshold according to the signal characteristics obtained within multiple sampling time windows.

[0026] In some embodiments, the above-mentioned processor is specifically configured to:

[0027] According to a preset sliding time window, obtain the extreme points in the first PIR signal and the extreme points in the second PIR signal;

[0028] Determine whether the motion trajectory of the moving target satisfies the alarm trigger condition according to the extreme points in the first PIR signal and the extreme points in the second PIR signal.

[0029] In some embodiments, the above-mentioned processor is specifically configured to:

[0030] Determine whether the motion trajectory of the moving target satisfies the alarm trigger condition in the following manner:

[0031] ;

[0032] ;

[0033] ;

[0034] Wherein, and respectively represent the number of minimum points and maximum points in the first PIR signal, and respectively represent the number of minimum points and maximum points in the second PIR signal, represents the maximum value of each minimum point in the first PIR signal, represents the minimum value of each minimum point in the first PIR signal, represents the maximum value of each minimum point in the second PIR signal, represents the minimum value of each minimum point in the second PIR signal, represents the extreme point quantity difference threshold, represents the extreme value difference threshold of the extreme points, When = 1, it is determined that the motion trajectory of the moving target satisfies the alarm trigger condition, When = 0, it is determined that the motion trajectory of the moving target does not satisfy the alarm trigger condition.

[0035] In some embodiments, the phase between the above-mentioned first PIR sensor and the second PIR sensor is adjustable.

[0036] In a second aspect, the present application provides a monitoring device control method, which is applied to a monitoring device. The monitoring device includes a first PIR sensor, a second PIR sensor, and a processor; there is an overlapping area between the first detection area corresponding to the first PIR sensor and the second detection area corresponding to the second PIR sensor; the above method includes:

[0037] Determine that a moving target appears in the first detection area or the second detection area;

[0038] Based on the first PIR data collected by the first PIR sensor and the second PIR data collected by the second PIR sensor, detect whether the above-mentioned moving target enters the above-mentioned overlapping area within a preset time period;

[0039] When it is detected that the above-mentioned moving target enters the above-mentioned overlapping area, determine whether the movement trajectory of the moving target meets the alarm trigger condition according to the first PIR data and the second PIR data;

[0040] If the movement trajectory meets the above-mentioned alarm trigger condition, an alarm message is output.

[0041] In a third aspect, the present application provides a computer-readable storage medium storing a computer program, which when executed by a processor, implements the monitoring device control method provided in the second aspect.

[0042] The monitoring device, its control method, and the computer-readable storage medium provided by the present application use the first PIR sensor and the first PIR sensor to jointly detect a moving target, which can significantly expand the detection field of view. At the same time, the edge monitoring area of a single PIR sensor is used as a warning area. When the moving target enters this warning area, the monitoring device can give an early warning, thereby accelerating the capture speed. In addition, when it is determined that the moving target enters the overlapping area, the authenticity of the moving target can be further verified based on the movement trajectory of the moving target, thereby effectively reducing false alarms and missed alarms and improving the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application and used together with the specification to explain the principles of the present application.

[0044] Figure 1 It is a schematic structural diagram of a monitoring device provided in an embodiment of the present application;

[0045] Figure 2 It is a schematic diagram of the monitoring area of a monitoring device provided in an embodiment of the present application;

[0046] Figure 3 It is a schematic diagram of the control flow of a monitoring device provided in an embodiment of the present application Figure 1 ;

[0047] Figure 4 It is a schematic diagram of the control flow of a monitoring device provided in an embodiment of the present application Figure 2 ;

[0048] Figure 5 It is a schematic diagram of the feature extraction process provided in an embodiment of the present application;

[0049] Figure 6 It is a schematic flowchart for periodically updating a judgment threshold provided in an embodiment of the present application;

[0050] Figure 7 It is a schematic diagram of the extreme point distribution under the misalignment of the PIR signal provided in an embodiment of the present application.

[0051] Through the above-mentioned drawings, specific embodiments of the present application have been shown, and there will be more detailed descriptions hereinafter. These drawings and written descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. Specific Embodiments

[0052] Here, the exemplary embodiments of the present application will be described in detail. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application.

[0053] For the convenience of clearly describing the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "exemplary" and "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly speaking, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0054] In the embodiments of the present application, words such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and effects. For example, the first PIR signal and the second PIR signal are only used to distinguish different signals, and their sequence is not limited. Those skilled in the art can understand that the words such as "first" and "second" do not limit the quantity and execution order, and the words such as "first" and "second" do not necessarily limit that they are different.

[0055] In the embodiments of the present application, "at least one" means one or more, and "a plurality" means two or more. "At least one (item)" or its similar expression refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, at least one (item) of a, b, or c can represent: a, b, c, a - b, a - c, b - c, or a - b - c. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the front and back associated objects.

[0056] The PIR sensor is a non-contact detection sensor based on the pyroelectric effect. Its working principle is that the internal pyroelectric element receives the infrared rays radiated by the human body or animals. When a person or an animal moves within its detection range, the temperature difference between the person or animal and the surrounding environment will cause a change in the infrared radiation field, and this change will cause the above-mentioned pyroelectric element to generate a weak electrical signal. After this signal is amplified and analyzed by the signal processor, once it exceeds the preset threshold, it can be determined that there is a person or an animal moving.

[0057] Currently, in the field of video surveillance, as a mainstream motion detection sensor with low power consumption and low cost, the PIR sensor has a high detection ability. However, since the PIR sensor is easily affected by the environmental temperature difference, it is mostly used indoors. For outdoor surveillance scenarios, there will be more false alarms. For example, when the environmental temperature changes, or is interfered by other heat sources (such as direct sunlight, heating equipment, hot air currents, etc.), the PIR sensor may wrongly trigger an alarm. In addition, the activities of small animals, light fluctuations, etc. may also cause false alarms, affecting the detection accuracy.

[0058] For outdoor surveillance scenarios, in some solutions, a light and dark partition lens can be designed on the PIR sensor, and at the same time, a delay mechanism is added to reduce false alarms. However, this solution will increase missed alarms and is not conducive to reducing power consumption. In other solutions, a temperature difference sensor can also be used to monitor the environmental temperature difference, and the sensitivity of the PIR sensor is adjusted according to the environmental temperature difference. Although this solution can reduce the probability of false alarms to a certain extent, it requires a high-precision environmental temperature detection ability. Otherwise, the environmental temperature error will still affect the detection effect.

[0059] In the face of the above technical problems, in the embodiments of the present application, a monitoring device is provided. It can use multiple PIR sensors to capture moving targets in indoor and outdoor scenarios, and by adjusting the phase between the PIR sensors, the monitorable range of the field of view can be expanded. Compared with the detection solution using a single PIR sensor, it can detect faster and verify the detection results, thereby improving the detection accuracy.

[0060] The following details the technical solutions provided by the present application through specific embodiments. It should be noted that the following several embodiments can exist independently or be combined with each other. For the same or similar content, it will not be repeated in different embodiments.

[0061] Refer to Figure 1 , Figure 1 which is a schematic structural diagram of a monitoring device provided in the embodiments of the present application.

[0062] In some embodiments, the monitoring device 100 includes a first PIR sensor 101, a second PIR sensor 102, and a processor 103.

[0063] The first PIR sensor 101 and the second PIR sensor 102 are used to detect the infrared radiation of people or animals within their detection areas. Taking the first PIR sensor 101 as an example, when there are organisms (such as people or animals) moving within its detection area, the first PIR sensor 101 can capture the changes in the infrared radiation released by these organisms and convert them into electrical signals. These electrical signals are then sent to the processor 103 for further processing and analysis.

[0064] In some embodiments, the detection area of the second PIR sensor 102 may partially overlap with the detection area of the first PIR sensor 101.

[0065] Exemplarily, referring to Figure 2 , Figure 2 is a schematic diagram of the monitoring area of a monitoring device provided in an embodiment of the present application.

[0066] In Figure 2 , the first detection area is the detection area corresponding to the first PIR sensor. When there is a moving target (such as a person or an animal) moving within the first detection area, the first PIR sensor can detect the changes in the infrared radiation released by the moving target.

[0067] The second detection area is the detection area corresponding to the second PIR sensor. When there is a moving target moving within the second detection area, the second PIR sensor can detect the changes in the infrared radiation released by the moving target.

[0068] There is an overlapping area between the first detection area and the second detection area. Within this area, both the first PIR sensor and the second PIR sensor can detect the changes in the infrared radiation released by the moving target.

[0069] In some embodiments, the phase between the first PIR sensor and the second PIR sensor is adjustable.

[0070] In some embodiments, according to the actual scenario requirements, the phase misalignment angle between the first PIR sensor and the second PIR sensor can be adjusted to improve the robustness and adaptability of the monitoring device.

[0071] Referring to Figure 3 , Figure 3 is a schematic diagram of the control flow of a monitoring device provided in an embodiment of the present application Figure 1 . In some embodiments, the above control flow includes:

[0072] S301. Determine whether a moving target enters.

[0073] In some embodiments, the above-mentioned processor can obtain in real time the first PIR data collected by the first PIR sensor and the second PIR data collected by the second PIR sensor, determine whether a moving target appears in the above-mentioned first detection area according to the first PIR data, and determine whether a moving target appears in the above-mentioned second detection area according to the second PIR data.

[0074] When it is determined that a moving target appears in the above-mentioned first detection area or the second detection area, step S302 can be continued. Otherwise, continue to monitor the above-mentioned first PIR data and the second PIR data.

[0075] S302. Obtain the first PIR data collected by the first PIR sensor and the second PIR data collected by the second PIR sensor.

[0076] In some embodiments, when it is determined that a moving target appears in any one of the above-mentioned first detection area or the second detection area, the latest PIR data of the first PIR sensor and the second PIR sensor can be continuously obtained to further verify the authenticity of the above-mentioned moving target.

[0077] S303. Based on the above-mentioned first PIR data and the second PIR data, detect whether the moving target enters the overlapping area.

[0078] In some embodiments, when it is determined that the moving target enters the overlapping area, S305 can be continued. Otherwise, S304 is executed.

[0079] S304. Determine whether the preset duration is exceeded.

[0080] In some embodiments, a preset duration can be set in advance for waiting for the moving target to possibly enter the overlapping area or leave the detection area. If the warning trigger condition is not satisfied after the preset duration is exceeded (such as the moving target does not enter the overlapping area, or has left the first detection area or the second detection area), return to execute S301 to start monitoring the above-mentioned first PIR data and the second PIR data again to determine whether a moving target enters. If the preset duration is not exceeded, return to execute S302 to continue obtaining and updating the PIR data to detect whether the moving target enters the above-mentioned overlapping area.

[0081] S305. According to the first PIR data and the second PIR data, determine whether the movement trajectory of the moving target satisfies the warning trigger condition.

[0082] In some embodiments, the motion trajectory of the moving target can be analyzed based on the first PIR data and the second PIR data. If the motion trajectory of the moving target meets the alarm trigger condition, then S306 is continued; otherwise, return to execute S304.

[0083] S306. Output an alarm message.

[0084] In some embodiments, when the motion trajectory of the moving target meets the alarm trigger condition, an alarm message is output. Optionally, the alarm message can be conveyed to the user or the monitoring system by means such as sound, light, and screen display.

[0085] In the embodiments of the present application, a monitoring device is provided, which can achieve the following beneficial effects:

[0086] (1) By combining the PIR data collected by the first PIR sensor and the second PIR sensor, the detection field of view of the monitoring device can be significantly expanded, which helps to cover a wider monitoring area and improve the coverage range of the monitoring device.

[0087] (2) Taking the edge monitoring area of a single PIR sensor as the early warning area, when a moving target enters this early warning area, the monitoring device can give an early warning, thereby accelerating the capture speed.

[0088] (3) The left and right viewing fields of the dual PIR sensors can be adjusted according to the actual scene requirements. By adjusting the phase misalignment angle between the first PIR sensor and the second PIR sensor, the detection range of the monitoring device can be optimized to better adapt to different monitoring environments.

[0089] (4) When it is determined that the moving target enters the overlapping area, the authenticity of the moving target can be further verified based on the motion trajectory of the moving target, thereby reducing false alarms and missed alarms and improving the detection accuracy.

[0090] Refer to Figure 4 , Figure 4 which is a schematic control flow of a monitoring device provided in the embodiments of the present application Figure 2 . In some embodiments, the above control flow includes:

[0091] S401. Determine whether a moving target enters.

[0092] In some embodiments, the above processor can obtain in real time the first PIR data collected by the first PIR sensor and the second PIR data collected by the second PIR sensor, determine whether a moving target appears in the above first detection area according to the first PIR data, and determine whether a moving target appears in the above second detection area according to the second PIR data.

[0093] When it is determined that a moving target appears in the above-mentioned first detection area or second detection area, step S402 can be continued. Otherwise, continue to monitor the above-mentioned first PIR data and second PIR data to determine whether a moving target enters.

[0094] S402. Perform downsampling and differential processing on the first PIR data collected by the first PIR sensor and the second PIR data collected by the second PIR sensor.

[0095] In some embodiments, the above-mentioned processor can obtain the above-mentioned first PIR data and second PIR data; perform downsampling on the first PIR data to obtain a first PIR signal, and perform downsampling on the second PIR data to obtain a second PIR signal; when the first signal change rate of the first PIR signal at two adjacent sampling time points is greater than a preset change threshold, it is determined that a moving target appears in the first detection area; when the second signal change rate of the second PIR signal at two adjacent sampling time points is greater than the change threshold, it is determined that a moving target appears in the second detection area.

[0096] S403. Determine a judgment threshold.

[0097] In some embodiments, it is possible to determine whether the current detection environment is stable according to the change conditions of the first PIR signal and the second PIR signal; if the current detection environment is stable, update the above-mentioned judgment threshold, otherwise do not update the above-mentioned judgment threshold.

[0098] In some embodiments, the above-mentioned judgment threshold can include a first threshold and a second threshold. The first threshold is a judgment threshold for detecting whether a moving target enters the overlapping area, and the second threshold is a judgment threshold for detecting whether the above-mentioned first PIR signal and second PIR signal are interference signals.

[0099] S404. Based on the above-mentioned judgment threshold, detect whether a moving target enters the overlapping area.

[0100] In some embodiments, when it is determined that a moving target enters the overlapping area, S406 can be continued, otherwise S405 is executed.

[0101] S405. Determine whether the preset duration is exceeded.

[0102] In some embodiments, if the alarm trigger condition (such as a moving target not entering the overlapping area) is still not met after exceeding the preset duration, return to execute S401 to restart monitoring whether a moving target enters. If the preset duration is not exceeded, return to execute S402 to continue obtaining and updating the above-mentioned first PIR data and second PIR data.

[0103] S406. Extreme point statistics.

[0104] In some embodiments, the extreme value changes of the first PIR signal and the second PIR signal within a fixed time window can be counted to determine the motion trajectory of the moving target passing through the overlapping region horizontally.

[0105] S407. Determine whether the motion trajectory of the moving target satisfies the alarm trigger condition.

[0106] It can be understood that if the phase of the first PIR sensor and the second PIR sensor is misaligned by 1 / 2 (or 1 / 4) cycle, when the moving target passes through the overlapping region, the phase difference between the extreme points of the first PIR signal and the second PIR signal is 1 / 2 (or 1 / 4) cycle. In some embodiments, the continuity of the motion trajectory of the moving target can be determined through the logic of the alternating appearance of the extreme points of the first PIR signal and the second PIR signal. If it is not continuous, it indicates that there is significant noise interference in the field of view, and the motion trajectory of the moving target does not satisfy the alarm trigger condition, and the false alarm information needs to be filtered.

[0107] In some embodiments, if the motion trajectory of the moving target satisfies the alarm trigger condition, then S408 is continued; otherwise, return to execute S405.

[0108] S408. Output an alarm message.

[0109] To better understand the embodiments of the present application, the above steps S402 to S407 are described in detail below.

[0110] In step S402, it can be understood that when the moving target enters the first detection region or the second detection region, there is a temperature difference ∆T between the moving target (heat source) and the ambient temperature. The radiation generated by the moving target will be absorbed by the first PIR sensor or the second PIR sensor, thereby causing the movement of a sufficient amount of charge, resulting in an obvious change in the detection value of the first PIR sensor or the second PIR sensor. When the moving target moves, in the time series, it can be observed that the detection value of the first PIR sensor or the second PIR sensor shows a trend of rapid increase or decrease.

[0111] In some embodiments, the first PIR sensor and the second PIR sensor can be equipped with a lens system, and the lens can be divided into multiple light and dark partitions. When the moving target passes through these lens light and dark partitions, the absorption and focusing effects of each partition on radiation will be different, resulting in obvious fluctuations in the detection values of the first PIR sensor and / or the second PIR sensor. This fluctuation pattern not only provides evidence of the presence of the moving target but can also be used to further analyze the motion trajectory and speed of the target.

[0112] In order to quickly and effectively identify the fluctuation of the above detection values, the single-channel PIR signal can be differentially processed to extract the fluctuation characteristics, so that the monitoring device can enter the early warning detection mode in advance and improve the real-time performance of the capture.

[0113] For example, assuming that the first PIR data corresponding to the first detection area is , the second PIR data corresponding to the second detection area is When the moving target enters the edge of the first detection area or the second detection area, the monitoring device will be awakened and the first PIR data With the second PIR data Perform down-sampling to obtain the first PIR signal arranged horizontally With the second PIR signal , the relationship is as follows:

[0114] ;

[0115] Among them, i represents the i-th PIR signal, is the observation frequency of the effective waveform, is the system timing sampling time, is the sampling function.

[0116] In some implementations, the speed and time at which the moving target enters the first detection area or the second detection area may be obtained by performing differential processing on the first PIR signal or the second PIR signal.

[0117] For example:

[0118] ;

[0119] in, It indicates the result of differential processing of PIR signal corresponding to channel i at time t. When the value is greater than the set change threshold, it means that the moving target crosses the detection area of ​​the i-th PIR sensor, and the monitoring device can enter the early warning detection stage at this time.

[0120] In step S404, the differential signal corresponding to the first PIR signal and the second PIR signal within a preset time period can be determined. ; Determine the differential signal The amplitude at sampling time t Is it less than the first threshold L? is less than L, then the above differential signal is determined The third signal change rate at sampling time point t compared to sampling time point t-1 Is it greater than the second threshold? ;when Greater than When it is determined that the moving target enters the above overlapping area.

[0121] Specifically, when the following formula is satisfied, it is determined that the moving target enters the above overlapping area:

[0122] ;

[0123] It can be understood that since the field of view angle of the monitoring device is basically the same as the above overlapping area, when the moving target enters the overlapping area from the edge of the first detection area or the second detection area, its above differential signal will decrease sharply.

[0124] In step S403, the signal characteristics of at least one of the following items can be obtained respectively according to a preset sampling time window: the first PIR signal , the second PIR signal , the differential signal , the first signal change rate , the second signal change rate , the third signal change rate ; the above signal characteristics include variance and peak-to-peak value. Update the first threshold and / or the second threshold according to the signal characteristics obtained within multiple sampling time windows.

[0125] Exemplarily, when the moving target enters the first detection area or the second detection area and triggers an early warning, the signal characteristics in the current time domain can be obtained: the variance of the signal change rate and , the signal variance and , the peak-to-peak value of the signal change rate and and the peak-to-peak value of the signal and .

[0126] In order to extract the feature differences before and after triggering, a timed sampling method is adopted in the embodiments of the present application. The main purpose is to record the environmental characteristics after the monitoring device wakes up, and update and with this feature.

[0127] Referring to Figure 5 , Figure 5 is a schematic diagram of a feature extraction process provided in the embodiments of the present application.

[0128] In some embodiments, the source data and the variance and peak-to-peak value of the data change rate under different time series can be obtained by timed extraction and caching (collecting N data) in multiple time periods. According to the variance and peak-to-peak value of the M-segment queue, the optimal variance and peak-to-peak value of the interference-free environment are calculated, and the peak-to-peak value is used as the basis for updating the threshold.

[0129] Exemplarily, the above first threshold and the second threshold can satisfy the following formula:

[0130] ;

[0131] ;

[0132] ;

[0133] ;

[0134] Wherein, is the eigenvalue queue of the target-free environment statistically sampled at regular intervals (the elements are the variance and peak-to-peak value of the statistical time period), is for the result after ascending sorting of the variance elements in the first row of the queue, is the sorting algorithm,

[0135] In some embodiments, when the maximum variance in any of the above queues is much larger than the mean variance of the current queue, the maximum variance can be deleted, otherwise it is used as a reference for updating the threshold.

[0136] Referring to Figure 6 Figure 6 FIG. is a schematic flow chart of a method for periodically updating a judgment threshold provided in an embodiment of the present application.

[0137] In some embodiments, the process of periodically updating the judgment threshold includes:

[0138] S601. Determine a timer interrupt.

[0139] In some embodiments, a timer can be preset, and the timer can trigger an interrupt periodically. The timer can ensure that the process of periodically updating the judgment threshold can be executed regularly.

[0140] S602. Sample and cache the PIR signal.

[0141] In some embodiments, the above PIR signal sampling cache includes a first PIR signal and a second PIR signal sampling cache.

[0142] ​In some embodiments, after a timer interrupt is triggered, the first PIR signal and the second PIR signal can be collected and cached.

[0143] S603. Determine whether the number of sampling points is greater than or equal to a preset number threshold.

[0144] In some embodiments, it is possible to check whether the number of sampling points of the cached PIR signal has reached the preset number threshold. If the number of sampling points is sufficient, proceed to the next step S604; otherwise, return to execute S602 to continue collecting and caching more PIR signals.

[0145] S604. Determine whether a detection warning is triggered.

[0146] In some embodiments, after the number of sampling points reaches the preset number threshold, these sampling points can be analyzed to determine whether a detection warning is triggered. If a detection warning is triggered, proceed to the next step S605; otherwise, return to execute S602 to continue collecting and caching PIR signals.

[0147] S605. Determine the signal characteristics.

[0148] In some embodiments, after determining that a detection warning is triggered, the cached PIR signal sampling points can be further analyzed to determine their signal characteristics.

[0149] S606. Update the judgment threshold.

[0150] In some embodiments, based on the analyzed signal characteristics, the above judgment threshold can be updated to improve the adaptability and accuracy of the monitoring device, enabling it to better handle target detection tasks under different environments and conditions.

[0151] In some embodiments, in a non-interference environment, the above signal characteristics can be directly extracted as a reference for updating the judgment threshold; in an interference environment, the above queue in the alarm environment can be screened until the next time valid signal characteristics are updated, and then included in the statistical and update process.

[0152] In some embodiments, for step S406, the extreme points in the first PIR signal and the extreme points in the second PIR signal can be obtained according to a preset sliding time window; according to the extreme points in the first PIR signal and the extreme points in the second PIR signal, it is determined whether the motion trajectory of the moving target satisfies the alarm trigger condition.

[0153] Exemplarily, when it is determined that the moving target enters the overlapping area, sampling statistics can be performed on the current first PIR signal and the second PIR signal, and the sliding time window the minimum value points in the data within and the maximum point , cache the current extreme point data.

[0154] In some embodiments, when it is determined that the moving target enters the overlapping area, start recording the timestamp count and extreme value size of the above extreme points. The relevant formulas are as follows:

[0155] ;

[0156] ;

[0157] where, is the timestamp subscript of the minimum point, is the minimum value size within the sliding window, sequence is the source data cached within the sliding time window.

[0158] ;

[0159] ;

[0160] where, is the timestamp subscript of the maximum point, is the maximum value size within the sliding time window, sequence is the source data cached within the sliding time window.

[0161] Exemplarily, referring to Figure 7 , Figure 7 is a schematic diagram of the extreme point distribution under PIR signal misalignment provided in the embodiment of the present application.

[0162] Since the lateral field of view of the lens of the PIR sensor is adjustable, by adjusting the distance between the lens partitions of the first PIR sensor and the second PIR sensor, the misalignment of the light and dark partitions of the PIR field of view can be achieved, thereby generating more partitions. When the moving target passes through these partitions, it will cause the PIR signal to rise or fall, generating multiple peaks and valleys. By comparing the peaks and valleys through continuity (such as Figure 7 shown), it can be determined whether the motion trajectory of the current moving target meets the alarm trigger condition.

[0163] From Figure 7 it can be seen that after the phase misalignment of the first PIR signal and the second PIR signal, the moving target is in the dark area compared to the first PIR sensor and in the bright area compared to the second PIR sensor at the same position. The motion trajectory of a single moving target has an obvious lag in the first PIR signal and the second PIR signal. According to the extreme point information of the first PIR signal and the second PIR signal when the moving target crosses the light and dark areas, two curves can be fitted.

[0164] If the coincidence degree of the above two curves is relatively high, it indicates that the above moving target truly exists; if the coincidence degree is low and the number of extreme points of the first PIR signal and the second PIR signal differs significantly, it indicates that there are interference sources in multiple points in the environment and it can be regarded as a false alarm.

[0165] Through the above method, it is possible to effectively filter out the interference of environmental factors such as the swaying of leaves and eliminate the excitation signals generated by the repeated switching of the shaded surface and the illuminated surface of the leaves in a single partition.

[0166] In some embodiments, due to the uncertainty of the outdoor environment and the moving target, there will be no obvious distinction in numerical values between the maximum value sequence and the minimum value sequence, and due to the continuity of the trajectory, the number of extreme points should be close. Therefore, when and differ significantly in number, it can be considered that the continuous increase in amplitude is caused by the change in the current environmental temperature. At the same time, a certain number of extreme points should be satisfied to indicate that there is a moving target in the detection environment, thereby filtering out the excitation signals generated by factors such as environmental disturbances.

[0167] The following are the preconditions for judging the continuity of extreme values:

[0168] ;

[0169] In the above formula, represents a function for counting the number of elements in the * sequence, is the minimum value sequence, is the maximum value sequence, is the upper limit of the number of valid detected extreme points, is the lower limit of the difference in the number of extreme points for judging the symmetry of the motion trajectory.

[0170] In some embodiments of the present application, since the radiation amount of the same moving target to the above overlapping region is basically consistent, and the corresponding extreme point curves have the same trend and are phase staggered in the overlapping part, therefore, by comparing the number and magnitude of extreme points of the PIR sensors distributed on the left and right, the motion trajectory equation of the target can be obtained, thereby screening out the influence of PIR false alarm data on the result.

[0171] Exemplarily, the motion trajectory of the moving target can be determined whether it meets the alarm trigger condition in the following way:

[0172] ;

[0173] ;

[0174] ;

[0175] Among them, and respectively represent the number of minimum points and maximum points in the first PIR signal, and respectively represent the number of minimum points and maximum points in the second PIR signal, represents the maximum value of each minimum point in the first PIR signal, represents the minimum value of each minimum point in the first PIR signal, represents the maximum value of each minimum point in the second PIR signal, represents the minimum value of each minimum point in the second PIR signal, represents the threshold of the difference in the number of extreme points, represents the threshold of the difference in the extreme values of the extreme points.

[0176] R is the PIR alarm output result, is the judgment result of the number of extreme points, is the judgment result of the extreme value size.

[0177] In some embodiments, when = 1, it is determined that the movement trajectory of the moving target satisfies the alarm trigger condition, when = 0, it is determined that the movement trajectory of the moving target does not satisfy the alarm trigger condition.

[0178] In some embodiments, when the number of extreme points of the two PIR signals is close, it indicates that the target trajectories coincide and the detection of the moving target is effective; when the number of extreme points of the two PIR signals differs greatly, it indicates that the moving target only enters the warning boundary of a single PIR sensor, or there is environmental noise (such as the scene of wind blowing leaves) interference in the detection area, and direct filtering is performed.

[0179] In some embodiments, when it is determined that the movement trajectory of the moving target does not satisfy the alarm trigger condition, an alarm is triggered, otherwise, it enters the timeout mechanism to wait for judgment, continues to detect within the time range, and stops detecting outside the time range, waiting to re - perform early warning and review after the next detection of the moving target entering.

[0180] The monitoring device provided by this application uses a combined scheme of multiple PIR sensors. By adjusting the phase between the PIR sensors, the monitorable range of the field of view can be expanded. Compared with a single PIR sensor, it can detect faster and perform misjudgment review, improving the detection accuracy. In the usage scenario of low - power devices, through the optical structure, physical partition changes are realized, and through software algorithms, differential feature extraction and target trajectory tracking of the misaligned PIR signals are performed, which can not only ensure the real - time detection but also ensure the capture accuracy.

[0181] In addition, the monitoring device provided by the present application can capture fast-moving targets in real time by extracting the differential characteristics of the signal, and has a higher real-time detection and capture capability for fast-moving targets; by recording the maximum and minimum points before and after the moving target crosses multiple partitions, the position of the current moving target in the PIR field of view can be determined by the number and distribution of extreme points; through the staggered distribution of dual PIR sensors, the signal change characteristics in the short-term time series can be detected, and the lateral crossing trajectory of the moving target can be tracked according to the alternating change characteristics of the staggered signal, and the authenticity of the target can be re-judged through the trajectory continuity, thereby improving the detection accuracy of regional crossing.

[0182] In some embodiments of the present application, a monitoring device control method is further provided, which can be applied to a monitoring device, wherein the monitoring device includes a first PIR sensor, a second PIR sensor, and a processor; a first detection area corresponding to the first PIR sensor and a second detection area corresponding to the second PIR sensor have an overlapping area; the above monitoring device control method includes:

[0183] Determining that a moving target appears in the first detection area or the second detection area;

[0184] Based on the first PIR data collected by the first PIR sensor and the second PIR data collected by the second PIR sensor, detecting whether the moving target enters the overlapping area within a preset time period;

[0185] When the moving target is detected to enter the overlapping area, determining whether the moving trajectory of the moving target meets the alarm triggering condition according to the first PIR data and the second PIR data;

[0186] If the motion trajectory meets the above alarm triggering conditions, the alarm information is output.

[0187] The monitoring device control method provided in the present application utilizes the first PIR sensor and the second PIR sensor to jointly detect the moving target, which can significantly expand the detection field of view. At the same time, the edge monitoring area of ​​the single PIR sensor is used as the early warning area. When the mobile target enters the early warning area, the monitoring device can issue an early warning, thereby speeding up the capture speed. In addition, when it is determined that the mobile target enters the overlapping area, the authenticity of the mobile target can be further verified based on the motion trajectory of the mobile target, thereby effectively reducing false alarms and missed alarms and improving the detection accuracy.

[0188] In some embodiments, the above method further comprises:

[0189] Acquire the first PIR data and the second PIR data;

[0190] Downsample the first PIR data to obtain a first PIR signal, and downsample the second PIR data to obtain a second PIR signal;

[0191] When the first signal change rate of the first PIR signal at two adjacent sampling time points is greater than a preset change threshold, it is determined that a moving target appears in the first detection area;

[0192] When the second signal change rate of the second PIR signal at two adjacent sampling time points is greater than the change threshold, it is determined that a moving target appears in the second detection area.

[0193] In some embodiments, the above method of detecting whether a moving target enters the overlapping area based on the first PIR data collected by the first PIR sensor and the second PIR data collected by the second PIR sensor within a preset duration includes:

[0194] Determine the differential signal corresponding to the first PIR signal and the second PIR signal within a preset duration;

[0195] Determine whether the amplitude of the differential signal at the sampling time point t is less than a first threshold;

[0196] If the amplitude of the differential signal at the sampling time point t is less than the first threshold, determine whether the third signal change rate of the differential signal at the sampling time point t compared to the sampling time point t - 1 is greater than a second threshold;

[0197] When the third signal change rate is greater than the second threshold, it is determined that the moving target enters the overlapping area.

[0198] In some embodiments, the above method further includes:

[0199] Determine whether the current detection environment is stable according to the change conditions of the first PIR signal and the second PIR signal;

[0200] If the current detection environment is stable, update the first threshold and / or the second threshold.

[0201] In some embodiments, the above update of the first threshold and / or the second threshold includes:

[0202] According to a preset sampling time window, respectively obtain the signal features of at least one of the following: the first PIR signal, the second PIR signal, the differential signal, the first signal change rate, the second signal change rate, the third signal change rate; the above signal features include variance and peak-to-peak value;

[0203] Update the first threshold and / or the second threshold according to the signal features obtained within multiple sampling time windows.

[0204] In some embodiments, determining whether the motion trajectory of the moving target satisfies the alarm trigger condition according to the first PIR data and the second PIR data includes:

[0205] Obtain the extreme points in the first PIR signal and the extreme points in the second PIR signal according to a preset sliding time window;

[0206] Determine whether the motion trajectory of the moving target satisfies the alarm trigger condition according to the extreme points in the first PIR signal and the extreme points in the second PIR signal.

[0207] In some embodiments, determining whether the motion trajectory of the moving target satisfies the alarm trigger condition according to the extreme points in the first PIR signal and the extreme points in the second PIR signal includes:

[0208] Determine whether the motion trajectory of the moving target satisfies the alarm trigger condition in the following manner:

[0209] ;

[0210] ;

[0211] ;

[0212] wherein, and respectively represent the number of minimum points and maximum points in the first PIR signal, and respectively represent the number of minimum points and maximum points in the second PIR signal, represents the maximum value of each minimum point in the first PIR signal, represents the minimum value of each minimum point in the first PIR signal, represents the maximum value of each minimum point in the second PIR signal, represents the minimum value of each minimum point in the second PIR signal, represents the extreme point quantity difference threshold, represents the extreme value difference threshold of the extreme points, When = 1, it is determined that the motion trajectory of the moving target satisfies the alarm trigger condition, When = 0, it is determined that the motion trajectory of the moving target does not satisfy the alarm trigger condition.

[0213] The present application also provides a computer-readable storage medium, which stores a computer program (which can also be called code or instruction). When the computer program is run, the monitoring device control method provided in the above embodiments can be implemented.

[0214] The present application also provides a computer program product, which includes: a computer program (which can also be referred to as code or instructions), and when the computer program is run, it can implement the monitoring device control method provided in the above-described embodiments.

[0215] It can be understood that the division of each unit or module in the above monitoring device is only a logical function division. Each function can correspond to a unit / function module, or two or more functions can be integrated into one unit / function module. In actual implementation, all or part of the units / modules can be integrated into a physical entity, or distributed among different physical entities. In addition, according to the actual situation, the above function modules may be implemented in the form of hardware, may also be implemented in the form of software, or may be implemented in a combination of hardware and software. Whether a certain function is executed in hardware or software depends on the specific application and design constraints of the technical solution. A person skilled in the art can use different methods to implement the described function for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0216] In the above embodiments, the processor can be a central processing unit (CPU), or can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method provided in combination with the present application can be directly implemented by the execution of the hardware processor, or can be implemented by the combination of the hardware and software modules in the processor.

[0217] In each embodiment of the present application, the functional units can be integrated in one processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0218] If a function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of various embodiments of this application. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs.

[0219] Finally, it should be noted that this application is intended to cover any variations, uses, or adaptations of this application, which follow the general principles of this application and include common general knowledge or conventional technical means in the technical field not claimed in this application. It is not limited to the exact structures already described and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is only limited by the appended claims.

Claims

1. A monitoring device, characterized in that, The monitoring device includes a first pyroelectric infrared PIR sensor, a second PIR sensor, and a processor; there is an overlapping area between a first detection area corresponding to the first PIR sensor and a second detection area corresponding to the second PIR sensor; the processor is configured to: Determine that a moving target appears in the first detection area or the second detection area; Based on first PIR data collected by the first PIR sensor and second PIR data collected by the second PIR sensor, detect whether the moving target enters the overlapping area within a preset time period; When it is detected that the moving target enters the overlapping area, obtain extreme points in the first PIR signal and extreme points in the second PIR signal according to a preset sliding time window, and determine whether the movement trajectory of the moving target meets an alarm trigger condition according to the number and extreme value magnitudes of the extreme points in the first PIR signal and the extreme points in the second PIR signal; wherein, the first PIR signal is obtained by downsampling the first PIR data, and the second PIR signal is obtained by downsampling the second PIR data; If the movement trajectory meets the alarm trigger condition, output an alarm message.

2. The monitoring device according to claim 1, wherein, The processor is further configured to: Obtain the first PIR data and the second PIR data; Downsample the first PIR data to obtain a first PIR signal, and downsample the second PIR data to obtain a second PIR signal; When a first signal change rate of the first PIR signal between two adjacent sampling time points is greater than a preset change threshold, determine that a moving target appears in the first detection area; When a second signal change rate of the second PIR signal between two adjacent sampling time points is greater than the change threshold, determine that a moving target appears in the second detection area.

3. The monitoring device according to claim 2, characterized in that, Specifically, the processor is configured to: Determine a differential signal corresponding to the first PIR signal and the second PIR signal within the preset time period; Determine whether an amplitude of the differential signal at a sampling time point t is less than a first threshold; If the amplitude of the differential signal at the sampling time point t is less than the first threshold, determine whether a third signal change rate of the differential signal at the sampling time point t compared to the sampling time point t - 1 is greater than a second threshold; When the third signal change rate is greater than the second threshold, determine that the moving target enters the overlapping area.

4. The monitoring device according to claim 3, wherein, The processor is further configured to: Determine whether the current detection environment is stable according to the change conditions of the first PIR signal and the second PIR signal; If the current detection environment is stable, update the first threshold and / or the second threshold.

5. The monitoring device according to claim 4, wherein Specifically, the processor is configured to: Obtain at least one of the following signal features according to a preset sampling time window: the first PIR signal, the second PIR signal, the differential signal, the first signal change rate, the second signal change rate, the third signal change rate; the signal features include variance and peak-to-peak value; Update the first threshold and / or the second threshold according to the signal features obtained within multiple sampling time windows.

6. The monitoring device according to claim 1, characterized in that, Specifically, the processor is configured to: Determine whether the motion trajectory of the moving target satisfies the alarm trigger condition in the following manner: ； ； ； Wherein, and respectively represent the numbers of the minimum points and the maximum points in the first PIR signal, and respectively represent the numbers of the minimum points and the maximum points in the second PIR signal, represents the maximum value of each minimum point in the first PIR signal, represents the minimum value of each minimum point in the first PIR signal, represents the maximum value of each minimum point in the second PIR signal, represents the minimum value of each minimum point in the second PIR signal, represents the threshold of the difference in the number of extreme points, represents the threshold of the difference in the extreme values of the extreme points, When, it is determined that the motion trajectory of the moving target satisfies the alarm trigger condition, When, it is determined that the motion trajectory of the moving target does not satisfy the alarm trigger condition.

7. The monitoring device according to any one of claims 1 to 6, characterized in that, The phase between the first PIR sensor and the second PIR sensor is adjustable.

8. A method for controlling a monitoring device, characterized in that, Applied to a monitoring device, the monitoring device includes a first PIR sensor, a second PIR sensor, and a processor; there is an overlapping area between a first detection area corresponding to the first PIR sensor and a second detection area corresponding to the second PIR sensor; the method includes: Determine that a moving target appears in the first detection area or the second detection area; Based on the first PIR data collected by the first PIR sensor and the second PIR data collected by the second PIR sensor, detect whether the moving target enters the overlapping area within a preset time period; When it is detected that the moving target enters the overlapping area, determine whether the motion trajectory of the moving target satisfies the alarm trigger condition according to the first PIR data and the second PIR data; If the motion trajectory satisfies the alarm trigger condition, output an alarm message; The determining whether the motion trajectory of the moving target satisfies the alarm trigger condition according to the first PIR data and the second PIR data includes: Obtain the extreme points in the first PIR signal and the extreme points in the second PIR signal according to a preset sliding time window; the first PIR signal is obtained by downsampling the first PIR data, and the second PIR signal is obtained by downsampling the second PIR data; Determine whether the motion trajectory of the moving target satisfies the alarm trigger condition according to the number and extreme values of the extreme points in the first PIR signal and the extreme points in the second PIR signal.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the monitoring device control method as claimed in claim 8.

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