Monitoring device and overexposure adjusting method

Abstract

The invention relates to the technical field of intelligent monitoring, in particular to a monitoring device and an overexposure adjusting method.The monitoring device comprises a camera module and a main control panel, and the camera module is provided with a first light sensor; the camera module is arranged on the main control board; the main control board is provided with a plurality of infrared light-emitting modules and at least one second light sensor, the second light sensor is configured to detect the light intensity of reflected light and generate corresponding electric signals according to the light intensity of the light, and the main control board adjusts the light-emitting intensity of the corresponding infrared light-emitting modules according to the electric signals. The light intensity values of the light rays in all directions received by the first light sensor are converged to a preset dynamic range. The invention mainly aims to provide a monitoring device, and aims to solve the problem of overexposure near a camera module and avoid the problems of image blurring, detail loss and the like caused by light intensity attenuation when a target is far away.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent monitoring, and particularly relates to a monitoring device and an overexposure adjustment method. Background Art

[0002] Intelligent monitoring devices (such as intelligent doorbells, intelligent door locks, and intelligent cameras), as an important part of modern security systems, have realized functions such as real-time environmental monitoring, abnormal behavior warning, and remote interaction by integrating cameras, sensors, and communication modules. Their core value lies in using artificial intelligence algorithms and Internet of Things technologies to break through the passive response mode of traditional security devices, actively sense environmental changes, and provide visual data support. For example, intelligent doorbells can accurately distinguish visitors from strangers through technologies such as face recognition and motion detection, and link to cloud storage and mobile terminals to provide users with all-weather front-door security protection capabilities, becoming a key entry device in smart home scenarios.

[0003] Taking the intelligent doorbell as an example, in actual deployment, the imaging quality of its camera module often deteriorates due to limited physical installation positions (such as being close to the wall or having obstacles). Specifically, when the infrared LED light source irradiates the adjacent wall, the infrared light reflected by the wall will form a locally high-brightness area, causing the light intensity received by the camera sensor to exceed the dynamic range and resulting in image overexposure. Existing technologies usually adopt a scheme of globally reducing the infrared light intensity to suppress overexposure. However, the applicant's research has found that this scheme has significant drawbacks: although reducing the infrared light intensity can alleviate the near-field overexposure problem, it will cause insufficient supplementary lighting in the far-distance area, resulting in problems such as blurred images and lost details when the camera captures distant targets due to light intensity attenuation. Summary of the Invention

[0004] The main objective of the present invention is to provide a monitoring device, aiming to solve the overexposure problem near the camera module while avoiding problems such as blurred images and lost details when capturing distant targets due to light intensity attenuation.

[0005] To achieve the above objective, the monitoring device proposed by the present invention includes: A camera module having a first light sensor; and A main control board, with the camera module disposed on the main control board; the main control board is provided with a plurality of infrared light-emitting modules and at least one second light sensor, the second light sensor is configured to detect the light intensity of the reflected light and generate corresponding electrical signals according to each of the light intensities, and the main control board adjusts the light-emitting intensity of the corresponding infrared light-emitting module according to each of the electrical signals so that the light intensity values of the light received by the first light sensor from each direction converge to a preset dynamic range.

[0006] In an embodiment of the present invention, the mounting surface of the main control board is arranged as a flat surface. The main control board has N infrared light-emitting modules and N second light sensors. The camera module is arranged at an end close to the mounting surface of the main control board. The N infrared light-emitting modules are located along a first height on the mounting surface of the main control board, and the N second light sensors are located along a second height on the mounting surface of the main control board and below the infrared light-emitting modules; the N infrared light-emitting modules and the N second light sensors are arranged at intervals along a first direction, and each infrared light-emitting module is arranged opposite to one second light sensor.

[0007] In an embodiment of the present invention, the main control board is provided with a first mounting surface, a second mounting surface and a third mounting surface. The second mounting surface is located between the first mounting surface and the third mounting surface, and the second mounting surface is arranged at an angle with both the first mounting surface and the third mounting surface; each mounting surface is provided with an infrared light-emitting module and a second light sensor. The camera module is arranged at an end close to the mounting surface of the main control board. Each infrared light-emitting module is located along a first height on the corresponding mounting surface of the main control board, and each second light sensor is located along a second height on the mounting surface of the main control board and below the infrared light-emitting module; each infrared light-emitting module and each second light sensor are arranged at intervals along a first direction, and each infrared light-emitting module is arranged opposite to one second light sensor.

[0008] In an embodiment of the present invention, the main control board is further provided with a distance measuring sensor, which is configured to detect the shortest distance between the monitoring device and an obstacle and generate a distance electrical signal; the main control board is further configured to calculate an initial drive current value corresponding to the infrared light-emitting module according to the distance electrical signal, and perform closed-loop correction on the initial drive current value according to the electrical signal generated by the second light sensor, so that the light intensity value received by the first light sensor converges to the preset dynamic range.

[0009] In an embodiment of the present invention, the optical axis of the distance measuring sensor is arranged parallel to the light-emitting axis of the corresponding infrared light-emitting module, and the field of view angle of the distance measuring sensor covers the illumination area of the infrared light-emitting module.

[0010] In an embodiment of the present invention, the second light sensor is a multi-spectral sensor, and the multi-spectral sensor has at least one visible light detection channel and an infrared detection channel. The visible light detection channel has a color temperature detection module, and the infrared detection channel is configured to detect the light intensity of the reflected light and generate corresponding electrical signals according to the light intensities; the main control board is further configured to adjust the light-emitting intensity of the corresponding infrared light-emitting module according to the color temperature signal of the visible light detection channel and the light intensity signal of the infrared detection channel.

[0011] In an embodiment of the present invention, narrowband filters are configured in both the visible light detection channel and the infrared detection channel to separate reflected spectra of different wavelengths.

[0012] The present invention also provides an overexposure adjustment method, which includes the following steps: Input an initial driving current to each infrared light-emitting module; Obtain a plurality of electrical signals generated by the reflected light intensity detected by the second photosensor under the initial driving current, and determine whether the plurality of electrical signals are within a preset current range; When at least one of the electrical signals is not within the preset current range, drive an adjustment current to each of the infrared light-emitting modules so that the light intensity value received by the first photosensor is within a preset dynamic range.

[0013] In an embodiment of the present invention, before inputting the initial driving current to each infrared light-emitting module, it further includes: Receive a distance electrical signal from a ranging sensor, where the distance electrical signal is generated by the ranging sensor detecting the shortest distance between the monitoring device and the occluder; Generate an initial driving current according to the distance electrical signal; The step of driving an adjustment current to each of the infrared light-emitting modules when at least one of the electrical signals is not within the preset current range includes: When at least one of the electrical signals is not within the preset current range, obtain the deviation value between the reflected light intensity of the second photosensor and the preset dynamic range, and generate a current adjustment amount according to the deviation value; Generate an adjustment current based on the initial driving current and the current adjustment amount and drive the adjustment current to each of the infrared light-emitting modules.

[0014] In an embodiment of the present invention, the step of generating an adjustment current based on the initial driving current and the current adjustment amount and driving the adjustment current to each of the infrared light-emitting modules includes: Obtain an ambient color temperature signal through the visible light detection channel of a multispectral sensor; Detect the reflected infrared light intensity through the infrared detection channel of the multispectral sensor; Calculate a color temperature compensation coefficient according to the ambient color temperature signal, and correct the initial driving current based on the shortest distance and the color temperature compensation coefficient; Generate an adjustment current based on the corrected initial driving current and the current adjustment amount and drive the adjustment current to each of the infrared light-emitting modules.

[0015] In the technical solution of the present invention, the second optical sensor directly detects the reflected light intensity of each LED array to accurately locate the overexposed area (such as wall reflection), avoiding the delay problem of the traditional solution relying on camera imaging feedback; the first optical sensor calibrates the target light intensity range based on the overall light flux of the imaging surface to ensure the final imaging quality. By adjusting the driving current of each LED in real time, the dynamic balance of "reducing light in the near field and supplementing light in the far field" is achieved; through multiple independently light-controlled infrared LED arrays, the supplementary light intensity can be adjusted separately for different distance / direction regions (such as the near-field wall and the far-field target), rather than globally reducing the light uniformly. When the reflected light in the near field is detected to be too strong, only the power of the LEDs in the corresponding direction is reduced, while the high light intensity is maintained in the far-field direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0017] Figure 1 It is a schematic structural diagram of an embodiment of the monitoring device provided by the present invention; Figure 2 Corresponding to Figure 1 The schematic diagram of the light rays of the shown structure; Figure 3 It is a schematic structural diagram of another embodiment of the monitoring device provided by the present invention; Figure 4 Corresponding to Figure 3 The schematic diagram of the light rays of the shown structure; Figure 5 It is a schematic flowchart of the first embodiment of the overexposure adjustment method provided by the present invention; Figure 6 It is a schematic flowchart of the second embodiment of the overexposure adjustment method provided by the present invention; Figure 7 It is a schematic flowchart of the third embodiment of the overexposure adjustment method provided by the present invention; Figure 8 It is a schematic flowchart of the fourth embodiment of the overexposure adjustment method provided by the present invention.

[0018] Explanation of the reference numerals in the drawings: 10, camera module; 20, main control board; 21, infrared light-emitting module; 22, second optical sensor.

[0019] The realization of the object of the present invention, functional features and advantages will be further described in conjunction with the embodiments and with reference to the drawings. Detailed implementation manners

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0022] In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and / or" appearing throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes the solution of A, or the solution of B, or the solution where A and B are satisfied simultaneously. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0023] In the prior art, the intelligent monitoring device often has an unbalanced supplementary lighting effect due to limited installation positions. When the infrared light source irradiates the adjacent wall surface, the reflected light forms a locally high-brightness area, causing the problem of image overexposure. The traditional solution adopts the method of globally reducing the light intensity to suppress overexposure, but this leads to insufficient supplementary lighting in the far-distance area and the imaging of the target object is blurred. For example, for an intelligent doorbell installed on the wall surface, its infrared light source covers both the proximal wall surface and the far-distance pedestrian passage at the same time, and a single light intensity adjustment cannot meet the supplementary lighting requirements of different areas.

[0024] To solve the above problems, the inventors found that there are significant differences in the reflected light intensities of different areas. If only relying on a single light intensity adjustment, it is impossible to balance the supplementary lighting requirements of each area specifically. By analyzing the light reflection path, it is found that the reflection area corresponding to each light-emitting unit has an independent light intensity characteristic. Based on this, the idea of independently controlling each light-emitting unit is proposed. By setting a plurality of light detection units to respectively collect the reflected light signals of the corresponding areas, the light intensity adjustment of different areas is realized.

[0025] Therefore, the present application proposes that the monitoring device includes a camera module 10 and a main control board 20. The camera module 10 is provided with a first light sensor; the main control board 20 is provided with a plurality of infrared light-emitting modules 21 and at least one second light sensor 22. The second light sensor 22 detects the light intensity of the reflected light and generates an electrical signal. The main control board 20 adjusts the intensity of the corresponding infrared light-emitting module 21 according to the electrical signal, so that the light intensity received by the first light sensor is within a preset dynamic range.

[0026] Among them, the first light sensor refers to a photosensitive element arranged inside the camera module 10, which can be specifically implemented by the photosensitive unit of a CMOS or CCD image sensor, and is used to monitor the actual light intensity entering the camera module 10 in real time; the second light sensor 22 refers to a photosensitive device independent of the camera module 10, which can be specifically implemented by a photodiode array. Each photodiode corresponds to the irradiation area of an infrared light-emitting module 21 and is used to detect the intensity of the reflected light in this area. The infrared light-emitting module 21 refers to a light-emitting unit with an independent drive circuit, which can be specifically formed by arranging multiple groups of infrared LED lamp beads, and the drive current of each group of lamp beads can be adjusted independently. The dynamic range refers to the light intensity interval in which the photosensitive element of the camera module 10 can clearly image, avoiding overexposure (too high light intensity) or underexposure (too low light intensity), and can be specifically determined by the exposure parameter threshold preset by the image processing chip.

[0027] Specifically, when the infrared light emitted by the infrared light-emitting module 21 irradiates the monitoring area, there are differences in the light intensity reflected by objects at different distances. The second light sensor 22 array respectively detects the reflected light intensity of the corresponding area of each infrared light-emitting module 21, and generates an electrical signal corresponding to the light intensity of each area. In this process, the main control board 20 first inputs an initial drive current to each infrared light-emitting module 21 in a time-sharing manner. The light intensities generated by each infrared light-emitting module 21 under the same initial drive current are roughly the same, and the light intensities detected by the second light sensor 22 will also be the same. When there is an obstacle such as a wall on one side of a certain infrared light-emitting module 21 of the monitoring device, due to the reflection of the wall, the light intensity detected by the photosensitive element of the second light sensor 22 when detecting this infrared light-emitting module 21 will be greater than the light intensity obtained by detecting other infrared light-emitting modules 21 due to the reflected light intensity. The photosensitive element will generate a corresponding change in the electrical signal according to the received light intensity. The generated electrical signal will be transmitted from the second light sensor 22 to a specific signal receiving port or pin on the main control board 20 through a wire or the corresponding wiring on a printed circuit board (PCB). The signal receiving circuit (including signal conditioning circuits such as amplifiers and filters) on the main control board 20 first performs preliminary processing on the received electrical signal to remove noise, amplify the signal amplitude, etc. Then, the microcontroller or processor in the main control board 20 will read the processed electrical signal, perform analog-to-digital conversion (ADC), convert the analog electrical signal into a digital signal, and conclude that there is an obstacle on one side of a certain infrared light-emitting module 21 of the monitoring device. The main control board 20 reduces the current of the infrared light-emitting module 21 close to the obstacle side. At the same time, in order to ensure that the overall light intensity remains unchanged and avoid blurry imaging in the distance, the current of the infrared light-emitting module 21 far from the obstacle side is increased, so as to ensure that the light intensities detected by the second light sensor 22 are the same, so that the light intensities of the light incident on each direction of the first sensor are basically the same, so as to achieve the elimination of the infrared overexposure problem while avoiding blurry imaging in the distance. Among them, "roughly the same" is because of the slight differences brought by the material uniformity, chip size, packaging process, etc. between the lamp beads of each infrared light-emitting module 21, resulting in the fact that the light output intensities of each lamp bead cannot be exactly the same under the same initial drive current. Therefore, it is only necessary to ensure that the light output intensities of each infrared light-emitting module 21 are in the light intensity area with the reference fixed value as the midpoint.

[0028] Through the above technical solution, the present application solves the problem of the contradiction between proximal overexposure and distal underexposure caused by single light intensity adjustment in the prior art, enables the monitoring device to automatically balance the supplementary light intensity of each area in a complex lighting environment, improves the imaging clarity of objects at different distances, and avoids the loss of image details caused by local overbrightness or overdarkness.

[0029] In some embodiments, the mounting surface of the main control board 20 is planar. The main control board 20 has N infrared light-emitting modules 21 and N second light sensors 22. The camera module 10 is arranged at an end close to the mounting surface of the main control board 20. The N infrared light-emitting modules 21 are located along a first height on the mounting surface of the main control board 20, and the N second light sensors 22 are located along a second height on the mounting surface of the main control board 20 and are below the infrared light-emitting modules 21. The N infrared light-emitting modules 21 and the N second light sensors 22 are arranged at intervals along a first direction, and each infrared light-emitting module 21 is arranged opposite to a second light sensor 22.

[0030] Among them, the mounting surface of the main control board 20 being planar means that the surface of the main control board 20 for carrying the infrared light-emitting modules 21 and the second light sensors 22 is a flat structure, which can be specifically implemented by using a rectangular or circular plate. This planar structure facilitates the installation of the infrared light-emitting modules 21 and the second light sensors 22 according to a preset layout. The first height and the second height refer to different positioning positions of the infrared light-emitting modules 21 and the second light sensors 22 in the vertical direction of the mounting surface, which can be specifically achieved by hierarchical arrangement or stepped layout. This height difference can avoid light interference caused by direct irradiation of the infrared light-emitting modules 21. The opposite arrangement means that there is a spatial correlation between the horizontal projection positions of a single infrared light-emitting module 21 and its corresponding second light sensor 22 on the mounting surface, which can be specifically implemented by a symmetric arrangement or a staggered arrangement. This structure can ensure that the reflected light detection area and the supplementary light area form a corresponding relationship.

[0031] Specifically, the planar mounting surface of the main control board 20 can realize the regular arrangement of multiple infrared light-emitting modules 21 and second light sensors 22. In one embodiment, please refer to Figure 1 and Figure 2, when the camera module 10 is close to the end of the mounting surface, three infrared light-emitting modules 21 form a horizontal array along the first height, and the emitted light thereof covers monitoring areas at different distances; the three infrared light-emitting modules 21 form a horizontal array along the first direction at the second height, so that each infrared light-emitting module 21 is arranged opposite to a second light sensor 22. The second light sensor 22 is located below the infrared light-emitting module 21 and can receive the reflected light after the corresponding infrared light-emitting module 21 irradiates the wall or an object. Each second light sensor 22 independently detects the reflected light intensity of the irradiation area of its corresponding infrared light-emitting module 21 and generates an independent electrical signal. The main control board 20 separately adjusts the current value of the corresponding infrared light-emitting module 21 according to each electrical signal. For example, when the reflected light intensity in a certain area is too high, the output power of the infrared light-emitting module 21 at this position is reduced, while for the area with insufficient reflected light intensity, the supplementary light intensity is increased, thereby realizing the independent dimming control of different monitoring areas. By arranging a plurality of independently controlled infrared light-emitting modules 21 and corresponding second light sensors 22 in layers according to height on the planar mounting surface, the detection and adjustment of the light intensity in sub-areas are realized. When the second light sensor 22 corresponding to a certain infrared light-emitting module 21 detects local overexposure, only the output of this infrared light-emitting module 21 needs to be adjusted, without reducing the overall supplementary light intensity, so as to maintain the supplementary light effect in the far-field area while suppressing near-field overexposure. In addition, the plurality of infrared light-emitting modules 21 are arranged at intervals along the first direction on one mounting surface, so that the monitoring device obtains a larger light-emitting area, so that the camera module 10 can obtain more monitoring information.

[0032] In some other embodiments, the main control board 20 is provided with a first mounting surface, a second mounting surface and a third mounting surface. The second mounting surface is located between the first mounting surface and the third mounting surface, and the second mounting surface forms an included angle with both the first mounting surface and the third mounting surface; each mounting surface is provided with an infrared light-emitting module 21 and a second light sensor 22. The camera module 10 is arranged close to the end of the mounting surface of the main control board 20. Each infrared light-emitting module 21 is located on the corresponding mounting surface of the main control board 20 along the first height, and each second light sensor 22 is located on the mounting surface of the main control board 20 along the second height and is located below the infrared light-emitting module 21; each infrared light-emitting module 21 and each second light sensor 22 are arranged at intervals along the first direction, and each infrared light-emitting module 21 is arranged opposite to a second light sensor 22. Among them, the mounting surface of the main control board 20 refers to the structural substrate carrying electronic devices, and specifically can be realized by using a rigid circuit board or a flexible substrate, and is used to fix the spatial positions of the infrared light-emitting module 21 and the second light sensor 22.

[0033] Among them, the included angle setting of the mounting surface means that a non-parallel spatial relationship is formed between adjacent surfaces, and specifically can be realized by a bending process or a split assembly, and is used to adjust the light coverage angle to avoid single-plane reflection interference.

[0034] In one embodiment, please refer toFigure 3 and Figure 4 , the three mounting surfaces of the main control board 20 form a stepped layout. Among them, the second mounting surface serves as an intermediate transition part, forming a non-coplanar structure with the first mounting surface and the third mounting surface on both sides. The angles formed by the second mounting surface with the first mounting surface and the third mounting surface on both sides are kept consistent. Each mounting surface is independently arranged with an infrared light-emitting module 21 and a second optical sensor 22. The infrared light-emitting module 21 is located at the upper part of the mounting surface, and the second optical sensor 22 is located at the lower part and is arranged at intervals with the corresponding infrared light-emitting module 21 in the horizontal direction. When the device works, each infrared light-emitting module 21 projects light at different angles, and the second optical sensor 22 detects the reflected light intensity in real time and feeds it back to the main control board 20. The main control board 20 independently adjusts the drive current of the corresponding infrared light-emitting module 21 based on the electrical signals of each sensor, so that the intensity of the reflected light received by the camera module 10 is always maintained within the dynamic range. The non-coplanar mounting surfaces can enable the infrared light-emitting module 21 to emit light outward from different angles, and the second optical sensor 22 can also receive the reflected light from different angles. The non-coplanar structure can cover a wider three-dimensional space, reduce lighting dead angles, improve the details and quality of the monitoring image, and is suitable for complex environments; at the same time, the non-coplanar mounting surfaces make each infrared light-emitting module 21 and the second optical sensor 22 correspond to specific areas and angles, and the main control board 20 can accurately adjust the light intensity of specific areas according to its electrical signals, realizing accurate and independent dimming of each area, and better meeting the supplementary light requirements of different areas; at the same time, the non-coplanar setting has more advantages in narrow or irregular spaces, which is convenient for the miniaturization design of the product.

[0035] Furthermore, the main control board 20 is also provided with a ranging sensor, and the ranging sensor is configured to detect the shortest distance between the monitoring device and the occluder and generate a distance electrical signal; the main control board 20 is also configured to calculate the initial drive current value of the corresponding infrared light-emitting module 21 according to the distance electrical signal, and adjust the initial drive current value according to the electrical signal generated by the second optical sensor 22, so that the light intensity value received by the first optical sensor is within the preset dynamic range.

[0036] First, it should be explained that a ranging sensor is a hardware module that can detect the distance between an object and a monitoring device. Common types include time-of-flight (ToF) sensors, ultrasonic sensors, or structured light sensors. Its core function is to emit signals (such as infrared light, ultrasonic waves) and receive the reflected signals, calculate the round-trip time or phase difference of the signals, and thus obtain the distance value; the shortest distance refers to the minimum value of the straight-line distance between the monitoring device and the occluder. For example, when a wall partially occludes the camera, the ranging sensor will preferentially detect the distance at the nearest point; the distance electrical signal is the quantized signal output by the ranging sensor, usually a digital value (such as centimeter-level distance data output through I²C / SPI interfaces) or an analog voltage signal (which needs to be converted to a digital value through an ADC); the initial drive current value is the preliminary drive current of the infrared light-emitting module 21 (IRLED) obtained based on the distance electrical signal through a pre-stored algorithm (such as a look-up table method, formula calculation), and is used to quickly respond to changes in the distance of the occluder.

[0037] Specifically, the ranging sensor is used to continuously detect the shortest distance between the occluder and the monitoring device in real time, generating a distance electrical signal; the main control board 20 first calculates the initial drive current of the infrared light-emitting module 21 according to the distance electrical signal (for example, the closer the distance, the lower the drive current to compensate for the too strong reflected light), and then combines the actual reflected light intensity detected by the second light sensor 22 (ALS) to correct the initial drive current (such as PID adjustment), and finally converges the light intensity received by the first light sensor of the camera to the preset dynamic range. This solution uses a composite mode of feed-forward control (distance prediction) combined with feedback control (light intensity correction), which can not only quickly respond to changes in the distance of the occluder but also ensure the compensation accuracy, solving the problems of large delay in single feedback control or susceptibility to environmental interference in single feed-forward control. In an embodiment, there is a wall occluder on the left side of the monitoring device. The ranging sensor detects that the shortest distance D from the wall is d and generates a corresponding distance electrical signal and transmits it to the main control board 20; the main control board 20 calls the pre-stored calibration formula I itial =K / D 2 (unit: mA, D is in meters, and K is the comprehensive calibration coefficient). First, according to the inverse square law of light, "the intensity of the action of an object or particle decreases linearly with the square of the distance, that is, the acting force is inversely proportional to the square of the distance", it can be known that: L∝1 / D 2 , further, assume that the drive current required at a reference shortest distance D0 is I0, and at this time the light intensity generated by an infrared light-emitting module 21 is L0. In actual application, when the distance becomes D, in order to maintain the same light intensity L0, the drive current needs to be adjusted to I, so that , and define as the comprehensive calibration coefficient K. In this way, the light intensity-current-distance relationship of the actual system is obtained through experimental calibration , considering the reflectivity of the white wall is , and thus ; Based on the obtained calibration formula, under the setting of the reflectivity ρ0 of the occluder and the distance d in an experimental test environment, determine the target light intensity L target When the target light intensity is L1, the target current value input to the infrared light-emitting module is I target , thus the comprehensive calibration coefficient can be obtained ; When the monitoring device is used in an actual scenario, at this time the reflectivity of the occluder is ρ1 and the distance is d1, it can be obtained that , based on the actual distance between the monitoring device and the occluder being d1, the actual current can be obtained ; When the reflected light intensity detected by the second light sensor 22 on the left is greater than the reflected light intensities detected by other second light sensors 22, the main control board 20 determines that there is overexposure of light intensity on that side, and defines the deviation light intensity as , and adjust it through the PID parameter tuning method. Specifically,[[]] , where K p is the proportional coefficient, K i is the integral coefficient, K d is the differential coefficient, reduce the initial drive current to , detect the reflected light intensity as L2 again, and the error is reduced to , after multiple iterative adjustments , thus determine that when the reflectivity of the occluder is and the distance is , the final current of the infrared light-emitting module 21 is , at this time the detection value of the second light sensor 22 on the left is , and it can fall into the preset dynamic range and be locked Operation; provide a procedural explanation for the above solution. Before the monitoring device leaves the factory, parameter debugging is carried out to determine the calibration coefficient K and the initial drive current. That is, under laboratory conditions, set an obstacle with a known distance D, and select a standard reflectivity material (such as a white wall) as the obstacle. Adjust the drive current of the infrared light-emitting module 21 until the light intensity received by the first light sensor of the camera module 10 reaches the optimal value within the preset dynamic range. At this time, the recorded drive current is the initial drive current. Using the calibration formula, combined with the experimental distance D and the initial drive current, calculate the comprehensive calibration coefficient K. This K value will be used as the basis for calculating the initial drive current in the subsequent actual scenario; when the monitoring device is installed in the actual scenario, the ranging sensor starts to work, measuring the actual shortest distance between the monitoring device and the obstacle. At the same time, the system needs to determine the reflectivity of the obstacle, which can be estimated through a preset default reflectivity (if the type of the obstacle is known) or by measuring the reflected light intensity in real time; according to the actual shortest distance measured by the ranging sensor, using the calibration coefficient K obtained during the calibration process, calculate a new initial drive current. This initial drive current takes into account the distance change in the actual application scenario. Since the reflectivity of the obstacle in the actual scenario is different from that in the experimental environment, the calibration coefficient K needs to be corrected. The correction process is based on the difference between the actual reflectivity and the experimental reflectivity. The corrected K value can more accurately reflect the light intensity-current-distance relationship in the actual scenario, thereby improving the accuracy of control. The main control board 20 sets the drive current of the infrared light-emitting module 21 according to the initial drive current calculated based on the corrected K value and the actual shortest distance. The second light sensor 22 detects the reflected light intensity at this time and generates an electrical signal to feedback to the main control board 20. The main control board 20 judges whether the current light intensity is within the preset dynamic range according to the feedback of the second light sensor 22. If the light intensity exceeds the range (too strong or too weak), the main control board 20 will adjust the drive current. After each adjustment, the new light intensity is detected by the second light sensor 22 until the light intensity stabilizes within the preset dynamic range. Once the reflected light intensity stabilizes within the preset dynamic range, the main control board 20 locks the current drive current value, and the monitoring device operates stably under this parameter. At the same time, the main control board 20 continues to monitor the change of the light intensity, ready to make new adjustments when the environmental conditions change. Through the above process, the monitoring device can automatically adjust the drive current of the infrared light-emitting module 21 under different environmental conditions, ensuring that the light intensity received by the camera module 10 is always within the optimal range, thereby improving the image quality and avoiding the loss of image details caused by local overbrightness or overdarkness.

[0038] Further, the optical axis of the ranging sensor is arranged parallel to the light-emitting axis of the corresponding infrared light-emitting module 21, and the field of view angle of the ranging sensor covers the illumination area of the infrared light-emitting module 21. It should be noted that the optical axis refers to the central axis direction of the ranging sensor for transmitting / receiving signals, which determines the spatial orientation of its detection area; the light-emitting axis refers to the central axis direction of the infrared light-emitting module 21 (IRLED) for emitting infrared light; the field of view angle refers to the angular range within which the ranging sensor can effectively detect objects. For example, a horizontal field of view angle of 60° means that objects within this angle can be detected; the illumination area refers to the spatial range covered by the infrared light emitted by the infrared light-emitting module 21, which is determined by the emission angle and installation position of the infrared light-emitting module 21.

[0039] Specifically, if a certain infrared light-emitting module 21 is responsible for illuminating the left area, the field of view angle of the corresponding ranging sensor needs to completely cover the left area. This design ensures that the distance detected by the ranging sensor strictly corresponds to the actual illumination area of the infrared light, avoiding distance detection errors caused by optical path deviation (such as the ranging sensor detecting the right distance but being used to adjust the left IRLED). At the same time, the requirement for the field of view angle coverage ensures that all potential occlusions within the infrared light illumination range can be captured by the ranging sensor, thereby improving the comprehensiveness of distance detection and the accuracy of the compensation strategy.

[0040] In one embodiment, the second optical sensor 22 is a multi-spectral sensor. The multi-spectral sensor has at least one visible light detection channel and one infrared detection channel. The visible light detection channel has a color temperature detection module, and the infrared detection channel is configured to detect the light intensity of the reflected light and generate corresponding electrical signals according to the respective light intensities; the main control board 20 is further configured to adjust the light emission intensity of the corresponding infrared light-emitting module 21 according to the color temperature signal of the visible light detection channel and the light intensity signal of the infrared detection channel. Among them, the multi-spectral sensor is a composite sensor integrating visible light and infrared light detection capabilities, including independent visible light channels and infrared channels, which can synchronously obtain ambient color temperature and infrared reflected light intensity data, such as RGB-IR sensors (such as Vishay VEML6040), spectroscopic multi-channel sensors (such as ams AS7265x). The visible light detection channel of the multi-spectral sensor is a module in the sensor for detecting the visible light band (380 - 780nm), usually including three sub-channels of red (R), green (G), and blue (B). The color temperature detection module calculates the color temperature of the ambient light source (unit: K) through the RGB response values, for example, based on the McCamy formula or the blackbody radiation curve interpolation algorithm; the color temperature signal refers to the quantified value of the ambient light source color temperature output by the visible light detection channel, which is used to characterize the "warm and cold" characteristics of the light source (such as 2700K is warm light, 6500K is cold light); the infrared detection channel is a module in the sensor for detecting the infrared band (such as 850 ± 10nm), configured with a narrow-band filter to isolate the ambient light in non-supplementary light bands, and it generates an electrical signal proportional to the light intensity by detecting the light intensity of the reflected light of the infrared light-emitting module; the light intensity signal is the quantified value of the reflected light intensity output by the infrared detection channel, which is used to feedback the actual supplementary light effect of the IRLED. Specifically, the visible light detection channel measures the ambient color temperature in real time, and the infrared detection channel measures the reflected light intensity of the IRLED in each direction. The reference current of the IRLED is dynamically adjusted according to the ambient color temperature. For example, in a low color temperature environment (such as 2700K warm light), the IR compensation is enhanced to offset the red light interference. First, the color temperature compensation coefficient is obtained: , where CCT is the color temperature of the current ambient light source; CCT ref is the reference color temperature value; K p is the proportional coefficient, which controls the adjustment intensity of the color temperature deviation on the compensation coefficient. Then, based on the feedback signal of the infrared detection channel, the current is adjusted through the PID algorithm to eliminate the light intensity deviation. The formula is as follows: ,

[0041] where, is the current adjustment amount, which is a correction value dynamically calculated according to the light intensity deviation; is the target light intensity (L 预设 ) and the actually detected light intensity (LIR ) light intensity deviation; According to the above, , output the final current to drive the infrared light-emitting module 21; In a scenario, the monitoring device is installed in a warm light porch (color temperature 2700K), close to a white wall (reflectivity 0.8) on the left, and there is no obstruction on the right. Based on the visible light channel of the multispectral sensor and a CCT of 2700K, it can be obtained that = 1.2. The light intensity detected by the multispectral sensor near the white wall obstruction is greater than that detected by the multispectral sensor far from the white wall obstruction. Through the above technical solution, the driving current of the infrared light-emitting module 21 near the white wall obstruction is adjusted from the initial driving current to , and the of the infrared light-emitting module 21 far from the white wall obstruction is 0. Therefore, the driving current remains the initial driving current unchanged. In this technical solution, by fusing the color temperature and infrared light intensity data of the multispectral sensor and combining the dynamic compensation algorithm, while solving overexposure and ensuring sufficient far-field fill light, it can identify different ambient light color temperatures to achieve ambient light adaptive infrared fill light control.

[0042] In an embodiment, before the monitoring device leaves the factory, parameter debugging is carried out. Set an obstruction with a known distance D ref , select a standard reflectivity material as the obstruction, adjust the driving current of the infrared light-emitting module 21 until the light intensity received by the first light sensor of the camera module 10 is at the best value within the preset dynamic range, and record the driving current at this time as the base driving current I basis , and record the color temperature CCT ref at this time; When the monitoring device is installed in the actual scenario, the ranging sensor starts to work, measures the actual distance D between the monitoring device and the obstruction, the multispectral sensor measures the color temperature CCT and the reflected light intensity of the ambient light in real time, and the infrared detection channel generates an electrical signal proportional to the reflected light intensity; The main control board 20 calculates the color temperature compensation coefficient α ref , using the formula , based on the current ambient color temperature CCT and the reference color temperature CCT cct . At the same time, the main control board 20 calculates the distance adjustment coefficient α ref using the formula α distance = (D ref / D)² based on the actual distance D and the reference distance D distance . Then, according to the base driving current I basis , the color temperature compensation coefficient α cct , and the distance adjustment coefficient α distance , calculate the preliminary driving current: I initial = I basis × α cct × αdistance ; Based on the deviation between the actual reflected light intensity and the target light intensity feedback by the infrared detection channel of the multispectral sensor, the main control board 20 calculates the feedback adjustment current , through . Based on the preliminary drive current I initial and the feedback adjustment current , the main control board 20 calculates the final drive current and drives the infrared light-emitting module 21; Specifically, in an embodiment, the monitoring device is installed in an environment with warm light illumination, close to a white wall (reflectivity 0.8) on the left, and the right side is a passage area without obstacles. The camera module 10 is arranged at the end close to the mounting surface of the main control board 20. There are three infrared light-emitting modules 21 and three multispectral sensors on the main control board 20. Each infrared light-emitting module 21 is arranged opposite to a multispectral sensor. Parameter calibration is carried out before this, and the distance of the obstacle is set to D ref = 1m, the ambient color temperature is CCT ref = 6500K. The drive current of the infrared light-emitting module 21 is adjusted to make the light intensity received by the first light sensor of the camera module 10 in the best state, and the basic drive current I basis = 200mA is recorded; In the installation scenario of warm light illumination, the distance measuring sensor measures that the distance between the left infrared light-emitting module 21 and the white wall is D left = 0.5m, the distance between the right infrared light-emitting module 21 and the passage area is D right = 3m. The multispectral sensor detects that the current ambient color temperature CCT = 2700K, and = 0.01 is set. The main control board 20 calculates the color temperature compensation coefficient = 1 + 0.01×(6500 - 2700) = 1.38 of the left infrared light-emitting module 21 according to the formula, and the color temperature compensation coefficient = 1 + 0.01×(6500 - 2700) = 1.38 of the right infrared light-emitting module 21. The main control board 20 calculates the distance adjustment coefficient α distanceleft = (1 / 0.5)² = 4 of the left infrared light-emitting module 21 according to the formula, and the distance adjustment coefficient α distanceright = (1 / 3)² = 0.111 of the right infrared light-emitting module 21. The main control board 20 calculates the preliminary drive current I initialleft = 200mA×1.38×4 = 1099.2mA of the left infrared light-emitting module 21, and the preliminary drive current I initialright = 200mA×1.38×0.111 = 30.108mA of the right infrared light-emitting module 21. Assume that at this time, the multispectral sensor detects that the actual reflected light intensity on the left is higher than the target light intensity, and the deviation is = 50Lux, and the actual reflected light intensity on the right is lower than the target light intensity, and the deviation is =-30 Lux. Set K p =0.5, K i =0.1, K d =0.05, calculate the left feedback adjustment current through the PID algorithm (assuming that ∑50 is the sum of the previous cumulative errors and d50 / dt is the error change rate), the right feedback adjustment current , the final drive current of the left infrared light-emitting module 21 , the final drive current of the right infrared light-emitting module 21 , the main control board 20 drives the infrared light-emitting module 21 according to the calculation results. The main control board 20 continuously adjusts according to the reflected light intensity data continuously fed back by the multispectral sensor , until the reflected light intensity stabilizes within the preset dynamic range. Finally, the drive current of the left infrared light-emitting module 21 stabilizes at I finalleft =1050 mA, and the drive current of the right infrared light-emitting module 21 stabilizes at I finalright =40 mA. The monitoring device operates stably under these parameters. In the image obtained by the camera module 10, the left area is not overexposed and the right area is sufficiently filled with light. In this way, objects at different distances are clearly imaged, making the image details rich.

[0043] In some embodiments, narrowband filters are configured for both the visible light detection channel and the infrared detection channel to separate the reflection spectra of different wavelengths. Specifically, narrowband filters are configured for both the visible light and infrared detection channels of the multispectral sensor. By precisely separating the reflection spectra of different wavelengths, the signal purity and anti-interference ability are improved. In one embodiment, three groups of narrowband filters (red light at 650 nm ± 10 nm, green light at 550 nm ± 10 nm, and blue light at 450 nm ± 10 nm) are configured for the visible light channel of the multispectral sensor to separate the RGB spectra and calculate the ambient color temperature; an 850 nm ± 10 nm narrowband filter is configured for the infrared channel to transmit only the reflected light in the IRLED supplementary lighting band and filter out the near-infrared stray light in sunlight (such as 800 - 900 nm). In this design, the visible light channel optimizes the infrared compensation strategy through precise color temperature detection (such as distinguishing warm light of 2700K and cold light of 6500K), while the infrared channel suppresses ambient light interference during the day to ensure the consistency of reflected light intensity detection at night and during the day. For example, when the smart doorbell is installed in a direct sunlight area, the 850 nm filter blocks the 840 - 860 nm stray light in sunlight, preventing the ALS from misjudging it as a high-reflection signal and avoiding the problem of under-exposure in the far field caused by abnormal current reduction of the IRLED; In another embodiment, narrowband filters for cold white light (480 nm ± 5 nm) and amber light (600 nm ± 10 nm) are added to the visible light channel of the multispectral sensor to enhance the analysis ability for mixed light sources (such as natural light, incandescent lamps, and LED lights); a 940 nm ± 20 nm narrow and wideband filter is configured for the infrared channel to match the invisible infrared supplementary lighting LED and be compatible with the wavelength temperature drift (±15 nm). In this solution, the cold white light channel identifies high-color-temperature ambient light (such as shopping mall neon lights) and triggers dynamic adjustment of the IR compensation intensity, while the 940 nm narrow and wideband filter avoids supplementary lighting exposure in covert monitoring scenarios (such as bank vaults), and at the same time allows slight deviation of the LED wavelength (such as a 935 - 945 nm drift caused by temperature change) to still effectively transmit the signal. For example, when the security camera is deployed in a commercial area with severe light pollution, the 480 nm filter precisely separates the cold white light interference, combined with the 940 nm covert supplementary lighting, to ensure clear night imaging and no exposure of the device position. In this way, narrowband filters are configured for both the visible light and infrared channels to isolate interference from non-target bands, improve signal purity, detect the color temperature of visible light and the light intensity of infrared, drive dynamic compensation through data fusion, and at the same time improve the anti-interference ability and effectively suppress the contamination of detection signals by ambient stray light (such as sunlight and artificial light sources).

[0044] The present application also proposes an overexposure adjustment method applied to a monitoring device. Please refer to Figure 5 , and the overexposure adjustment method includes: Step S20: Input an initial driving current to each infrared light-emitting module 21; Step S30: Obtain multiple electrical signals generated by the reflected light intensity detected by the second light sensor 22 under the initial driving current, and determine whether the multiple electrical signals are within a preset current range; Step S40: When at least one electrical signal is not within the preset current range, input an adjustment current to each infrared light-emitting module 21 so that the light intensity value received by the first light sensor is within a preset dynamic range.

[0045] It can be understood that the overexposure adjustment method proposed in this application is applied to the above-mentioned monitoring device, and the monitoring device can be applied in multiple scenarios, such as being installed in environments such as household entrance doors, factories, municipal parks, parking lots, etc., which are not limited here.

[0046] In step S20, the initial driving current provides a starting working current for the infrared light-emitting module 21, enabling it to start emitting infrared light. The main control board 20 outputs a predetermined initial driving current to each infrared light-emitting module 21, and this current value is usually obtained based on past experience or experimental calibration, aiming to make the infrared light-emitting module 21 output an appropriate light intensity under ideal conditions such as without obstacles. For example, in the smart doorbell scenario, all infrared emission modules are started with the same current (such as 200 mA) to avoid instantaneous overexposure caused by a sudden increase on one side.

[0047] In step S30, the second light sensor 22 (such as a photodiode array) is used to detect the reflected light intensity of the corresponding area of each infrared light-emitting module 21 in real time, and convert it into an electrical signal (such as a voltage value). The main control board 20 compares the electrical signal with a preset current range (such as 0.5 to 2.0 V corresponding to 50 to 200 Lux) to identify abnormal areas. For example, when the left sensor detects 2.5 V (corresponding to 250 Lux), it is determined that the area is overexposed.

[0048] In step S40, according to the feedback result of the second sensor, the main control board 20 dynamically adjusts the current of the infrared light-emitting module 21 corresponding to the abnormal area through the PID algorithm. For example, the current of the left infrared light-emitting module 21 is reduced from 200 mA to 150 mA, and the current of the right one is increased from 200 mA to 250 mA, so that the overall light intensity received by the first light sensor (CMOS photosensitive unit) of the camera module 10 is stabilized within a preset dynamic range (such as 100 ± 20 Lux).

[0049] Thus, by setting multiple individually driven infrared adjustment modules, the contradiction between proximal overexposure and distal underexposure caused by single light intensity adjustment in traditional monitoring devices is effectively solved. Specifically, the reflected light intensity in the corresponding areas of each infrared light-emitting module 21 is independently detected by the second light sensor 22 array, and combined with the global light intensity verification of the first light sensor, precise current reduction in local overexposed areas and targeted light compensation in underexposed areas are achieved. For example, in the scenario of an intelligent doorbell, the current of the infrared light-emitting module 21 close to the wall is reduced to suppress reflected overexposure, while the current of the module in the distal pedestrian passage is synchronously increased to ensure clear imaging of distant targets. This method not only avoids the degradation of image quality caused by traditional global dimming but also significantly improves the overall imaging uniformity in complex spaces through a two-stage feedback mechanism (local detection + global balance), especially suitable for installation environments with significant reflection differences (such as corridors, corners, etc.).

[0050] Please refer to Figure 6 , before step S20, it further includes: Step S10: Receive the distance electrical signal from the ranging sensor, where the distance electrical signal is generated by the ranging sensor detecting the shortest distance between the monitoring device and the occluder; Step S11: Generate an initial drive current according to the distance electrical signal; In step S10, the ranging sensor is electrically connected to the power supply module and the main control board 20 of the main control device. The ranging sensor (such as a ToF module) detects the shortest distance between the monitoring device and the occluder (such as the wall distance of 0.5 m) and generates a digital signal (such as the distance value output through the I²C interface). This step mainly provides a key input for feedforward control. For example, in the corridor monitoring scenario, the distance to the nearest obstacle (such as a pillar) is preferentially detected instead of the distal ground (3 m).

[0051] In step S11, the main control board 20 calls the pre-stored calibration formula I initial = K / D² (K is the calibration coefficient, D is the ranging value) to calculate the initial drive current. For example, when K = 200 mA·m² and D = 0.5 m, I_initial = 200 / (0.5²) = 800 mA. This step pre-compensates through the inverse square law to shorten the adjustment time and avoid overexposure delay caused by sudden distance changes in traditional schemes.

[0052] Please refer to Figure 7 , step S40, further includes: Step S41: When at least one electrical signal is not within the preset current range, obtain the deviation value between the reflected light intensity of the second light sensor 22 and the preset dynamic range, and generate a current adjustment amount according to the deviation value; Step S42: Generate an adjusted current based on the initial drive current and the current adjustment amount and drive the adjusted current to each infrared light-emitting module 21.

[0053] In step S41, the main control board 20 calculates the deviation between the detection value of the second optical sensor 22 and the target value , and through the PID formula , , dynamically generates an adjustment amount. For example, if the reflected light intensity on the left exceeds the target value, after PID calculation, . This step combines feedforward and feedback control to eliminate the influence of environmental reflectivity differences (such as white walls and dark walls) on dimming.

[0054] In step S42, the initial drive current and the adjustment amount are superimposed, I final =I initial + , and the corresponding infrared light-emitting modules 21 are driven in regions. In this step, through dynamic balance, proximal current reduction is achieved to suppress overexposure, and distal current increase is maintained to provide supplementary lighting, ensuring clear global imaging of the camera module 10.

[0055] In this way, the distance sensor is used to obtain the distance of the occluder in real time and generate the initial drive current (pre-compensated based on the inverse square law), quickly approaching the target light intensity range, and shortening the adjustment delay of traditional pure feedback control. At the same time, combined with the light intensity deviation value detected by the second optical sensor 22, PID fine correction is performed, effectively eliminating the adjustment error caused by sudden changes in the reflectivity of the occluder (such as changes in wall materials) or environmental interference (such as temporary obstacles). For example, in the scenario of a security camera, when a suddenly approaching obstacle (distance shortened from 3m to 1m) is detected, the system can immediately reduce the current of the corresponding area infrared light-emitting module 21 to avoid instantaneous overexposure, and at the same time maintain the stability of distal supplementary lighting through the PID algorithm, showing stronger robustness in complex dynamic scenarios (such as crowded areas), taking into account both the dimming speed and accuracy.

[0056] Please refer to Figure 8 , step S42, which also includes: Step S421: Obtain the environmental color temperature signal through the visible light detection channel of the multispectral sensor; Step S422: Detect the reflected infrared light intensity through the infrared detection channel of the multispectral sensor; Step S423: Calculate the color temperature compensation coefficient according to the environmental color temperature signal, and correct the initial drive current based on the shortest distance and the color temperature compensation coefficient; Step S424: Generate an adjusted current based on the corrected initial drive current and the current adjustment amount and drive the adjusted current to each infrared light-emitting module 21.

[0057] In steps S421 and S422, the color temperature signal of the current environment is obtained using the visible light detection channel of the multispectral sensor. At the same time, the intensity of the reflected infrared light is detected through the infrared detection channel of the multispectral sensor. This operation enables the monitoring device to obtain two key parameters, namely the color temperature of the ambient light and the infrared reflection light intensity, providing more abundant information for subsequent precise supplementary light control.

[0058] In step S423, based on the obtained ambient color temperature signal, the main control board 20 calculates the color temperature compensation coefficient using a preset formula (such as ). At the same time, in combination with the shortest distance detected by the ranging sensor, the main control board 20 corrects the initial drive current using the color temperature compensation coefficient. This correction process comprehensively considers the influence of ambient color temperature on infrared supplementary light and the light intensity requirement based on the distance of the obstacle, making the initial drive current more in line with the requirements of the actual scenario and further improving the adaptability and accuracy of the supplementary light control.

[0059] In step S423, after obtaining the corrected initial drive current and the current adjustment amount calculated based on the reflected light intensity deviation, the main control board 20 combines the two to generate the final adjustment current. This adjustment current is driven to each infrared light-emitting module 21 to precisely adjust its light-emitting intensity. In this way, the monitoring device can, under complex environments, achieve precise control of the infrared light-emitting module 21 according to multiple factors such as ambient color temperature, obstacle distance, and reflected light intensity, ensuring that the light intensity received by the camera module 10 always remains within the preset dynamic range, thereby obtaining high-quality and clear monitoring images.

[0060] Based on the above technical solutions, by comprehensively considering the distance factor and the color temperature factor, precise control of the infrared light-emitting module 21 is achieved. In actual application scenarios, the distance between the monitoring device and the occluder, as well as the color temperature of the ambient light, will have a significant impact on the supplementary lighting effect. This method uses a distance measurement sensor to obtain the shortest distance between the monitoring device and the occluder, and generates an initial drive current accordingly, ensuring the adaptability of the initial supplementary lighting intensity to the distance. At the same time, the ambient color temperature signal is obtained through the visible light detection channel of the multispectral sensor, and the color temperature compensation coefficient is calculated to adjust the drive current of the infrared light-emitting module 21, effectively offsetting the impact of ambient color temperature changes on the supplementary lighting effect. For example, infrared compensation is enhanced in a low-color-temperature environment to overcome red light interference. Secondly, this method further optimizes the supplementary lighting effect through a feedback control mechanism. On the basis of the preliminary adjustment according to the initial drive current and the color temperature compensation coefficient, a current adjustment amount is also generated according to the deviation value between the reflected light intensity detected by the second optical sensor 22 and the preset dynamic range, realizing fine adjustment of the drive current. This composite control mode combining feedforward control (distance prediction) and feedback control (light intensity correction) can not only quickly respond to changes in the occluder distance and ambient color temperature, but also ensure the accuracy of the supplementary lighting intensity, avoiding problems such as delay or error that may occur in a single control method. Finally, this method effectively solves the contradiction problem of overexposure at the proximal end and underexposure at the distal end caused by single light intensity adjustment in the prior art. The monitoring device can automatically balance the supplementary lighting intensity of each area in a complex lighting environment. By independently controlling the drive current of the infrared light-emitting module 21 in different areas and making targeted adjustments according to the reflected light intensity feedback in different areas, it is ensured that the light intensity received by the camera module 10 is always within the preset dynamic range, thereby improving the image quality and avoiding the loss of image details caused by local overbrightness or overdarkness. It has significant beneficial effects in improving the monitoring image quality, enhancing the system adaptability and reliability, etc.

[0061] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. All equivalent structural transformations made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A monitoring device, characterized in that, The monitoring device includes: a camera module (10) having a first light sensor; and a main control board (20) with the camera module (10) disposed thereon; the main control board (20) is provided with a plurality of infrared light-emitting modules (21) and at least one second light sensor (22), the second light sensor (22) is configured to detect the light intensity of the reflected light and generate corresponding electrical signals according to the light intensities, and the main control board (20) adjusts the light-emitting intensity of the corresponding infrared light-emitting module (21) according to the electrical signals, so that the light intensity values of the light received by the first light sensor in all directions are within a preset dynamic range.

2. The monitoring device according to claim 1, characterized in that, The mounting surface of the main control board (20) is flat, the main control board (20) has N infrared light-emitting modules (21) and N second light sensors (22), the camera module (10) is arranged near the end of the mounting surface of the main control board (20), the N infrared light-emitting modules (21) are located along a first height on the mounting surface of the main control board (20), the N second light sensors (22) are located along a second height on the mounting surface of the main control board (20) and below the infrared light-emitting modules (21); the N infrared light-emitting modules (21) and the N second light sensors (22) are arranged at intervals along a first direction, and each infrared light-emitting module (21) is arranged opposite to a second light sensor (22).

3. The monitoring device according to claim 1, characterized in that, The main control board (20) is provided with a first mounting surface, a second mounting surface and a third mounting surface, the second mounting surface is located between the first mounting surface and the third mounting surface, and the second mounting surface forms an angle with both the first mounting surface and the third mounting surface; each mounting surface is provided with an infrared light-emitting module (21) and a second light sensor (22), the camera module (10) is arranged near the end of the mounting surface of the main control board (20), the infrared light-emitting modules (21) are respectively located along a first height on the corresponding mounting surfaces of the main control board (20), the second light sensors (22) are located along a second height on the mounting surface of the main control board (20) and below the infrared light-emitting modules (21); the infrared light-emitting modules (21) and the second light sensors (22) are arranged at intervals along a first direction, and each infrared light-emitting module (21) is arranged opposite to a second light sensor (22).

4. The monitoring device according to any one of claims 1 to 3, characterized in that, The main control board (20) is further provided with a distance sensor configured to detect the shortest distance between the monitoring device and an obstacle and generate a distance electrical signal; the main control board (20) is further configured to calculate an initial drive current value corresponding to the infrared light-emitting module (21) according to the distance electrical signal, and adjust the initial drive current value according to the electrical signal generated by the second light sensor (22), so that the light intensity value received by the first light sensor is within the preset dynamic range.

5. The monitoring device according to claim 4, characterized in that, The optical axis of the ranging sensor is arranged parallel to the light-emitting axis of the corresponding infrared light-emitting module (21), and the field of view angle of the ranging sensor covers the illumination area of the infrared light-emitting module (21).

6. The monitoring device according to claim 4, wherein The second optical sensor (22) is a multi-spectral sensor. The multi-spectral sensor has at least one visible light detection channel and one infrared detection channel. The visible light detection channel has a color temperature detection module. The infrared detection channel is configured to detect the light intensity of the reflected light and generate corresponding electrical signals according to the light intensities of the respective lights. The main control board (20) is further configured to adjust the light-emitting intensity of the corresponding infrared light-emitting module (21) according to the color temperature signal of the visible light detection channel and the light intensity signal of the infrared detection channel.

7. The monitoring device according to claim 6, wherein, Both the visible light detection channel and the infrared detection channel are configured with narrow-band optical filters to separate the reflected spectra of different wavelengths.

8. A method for overexposure adjustment of a monitoring device, which is used for the monitoring device according to any one of claims 1 to 7, characterized in that, The method includes the following steps: Input an initial drive current to each infrared light-emitting module (21); Obtain a plurality of electrical signals generated by the reflected light intensity detected by the second optical sensor (22) under the initial drive current, and determine whether the plurality of electrical signals are within a preset current range; When at least one of the electrical signals is not within the preset current range, input an adjustment current to each of the infrared light-emitting modules (21) so that the light intensity value received by the first optical sensor is within a preset dynamic range.

9. The overexposure adjustment method according to claim 8, wherein Before inputting the initial drive current to each infrared light-emitting module (21), it further includes: Receiving a distance electrical signal from the ranging sensor, where the distance electrical signal is generated by the ranging sensor detecting the shortest distance between the monitoring device and the occluding object; Generating an initial drive current according to the distance electrical signal; The step of inputting an adjustment current to each of the infrared light-emitting modules (21) when at least one of the electrical signals is not within the preset current range includes: When at least one of the electrical signals is not within the preset current range, obtain the deviation value between the reflected light intensity of the second optical sensor (22) and the preset dynamic range, and generate a current adjustment amount according to the deviation value; Generate an adjustment current based on the initial drive current and the current adjustment amount and drive the adjustment current to each of the infrared light-emitting modules (21).

10. The overexposure adjustment method of the monitoring device according to claim 9, characterized in that, The generating an adjustment current based on the initial drive current and the current adjustment amount and driving the adjustment current to each of the infrared light-emitting modules (21) includes: Obtaining an ambient color temperature signal through the visible light detection channel of the multi-spectral sensor; Detecting the reflected infrared light intensity through the infrared detection channel of the multi-spectral sensor; Calculating a color temperature compensation coefficient according to the ambient color temperature signal, and correcting the initial drive current based on the shortest distance and the color temperature compensation coefficient; Generating an adjustment current based on the corrected initial drive current and the current adjustment amount and driving the adjustment current to each of the infrared light-emitting modules (21).

Images