Camera-based vehicle interior light supplement control method and system

Abstract

The invention relates to a camera-based vehicle interior light supplement control method and system, and the method comprises the steps: determining the brightness of an environment in a vehicle through the exposure value of a camera, and carrying out the automatic adjustment of the brightness of a light supplement LED array and the brightness of a vehicle-mounted screen according to the brightness. The imaging quality and stability of the camera in the vehicle in a weak light and variable light environment are effectively improved; the method not only solves the problems that the traditional automatic exposure is insufficient in effect under low illumination and a simple light supplementing mode cannot intelligently adapt to the environment, but also considers the influence of an in-vehicle screen on imaging and brings the influence into unified control, and the camera self-exposure adjustment is assisted after the main light environment is adjusted. Therefore, a clearer and more reliable image input basis is provided for applications such as vehicle-mounted face recognition and state monitoring.

Description

Technical Field

[0001] The present application relates to the technical field of camera fill light, and particularly to a method and system for controlling interior fill light of a vehicle based on a camera. Background Art

[0002] With the acceleration of the process of vehicle intelligence and networking, cameras have become indispensable sensing components inside modern vehicles and are widely used in various scenarios such as driver monitoring system (DMS), passenger identification, interior environment monitoring, video communication, and even in-cabin interaction. The performance of these advanced functions is closely related to the quality of the images captured by the camera. Clear and stable images are the basis for ensuring their accuracy and reliability. However, the lighting environment inside the vehicle is extremely complex and dynamically variable. Especially under low-light conditions such as night driving, passing through tunnels, entering or exiting underground garages, or encountering rainy or cloudy weather, the ambient light intensity is significantly insufficient, which directly leads to low brightness, noisy, and loss of key details in the images captured by the camera, thus severely restricting the actual effectiveness of the above-mentioned in-vehicle applications that rely on visual information.

[0003] To adapt to changing lighting conditions and obtain an ideal image brightness as much as possible, existing in-vehicle cameras usually integrate an automatic exposure (AE) function. This function analyzes the image brightness in real time through the image signal processor (ISP) inside the camera and automatically adjusts parameters such as the exposure time, aperture size, and sensitivity of the camera accordingly, striving to compensate for the influence of ambient light and output an image with a visually moderate brightness. For a specific camera module, its automatic exposure provides a certain degree of environmental adaptability. However, when the ambient light is extremely low, its adjustment ability often reaches a bottleneck: to obtain sufficient brightness, AE may be forced to use an overly long exposure time, which is prone to motion blur; or significantly increase the sensitivity, resulting in a sharp increase in image noise and deterioration of image quality.

[0004] To make up for the deficiencies of automatic exposure in low-light environments, the industry generally adopts the technical means of installing auxiliary light sources inside the vehicle for active fill light. However, the constant fill light method cannot adapt to the dynamic changes of ambient light, and is prone to insufficient fill light or overexposure under certain conditions, and sometimes even causes discomforting glare to the driver and passengers. Another some solutions allow users to manually adjust the fill light brightness, but this increases the operation burden and cannot achieve convenient automatic adaptation. Summary of the Invention

[0005] To solve the above problems, the present application provides a method and system for controlling interior fill light of a vehicle based on a camera, which achieves stable and high-quality camera imaging effects inside the vehicle, especially under low-light conditions.

[0006] To achieve the above object, in a first aspect, an embodiment of the present application provides a method for controlling interior fill light of a vehicle based on a camera, including the following steps:

[0007] S101. Start the camera to make it in the working state, and obtain the current exposure value of the camera;

[0008] S102. Based on the preset sensitivity characteristics of the camera, determine the current environmental brightness level of the vehicle interior according to the current exposure value;

[0009] S103. Based on a preset first correspondence, determine the target fill light brightness level of a fill light LED array according to the current environmental brightness level, where the first correspondence is an inverse correspondence between the environmental brightness level and the target fill light brightness level;

[0010] S104. Based on a preset second correspondence, determine the target screen brightness level of at least one vehicle-mounted screen according to the current environmental brightness level, where the second correspondence is a direct correspondence between the environmental brightness level and the target screen brightness level;

[0011] S105. Control the fill light LED array to adjust to the target fill light brightness level;

[0012] S106. Control at least one of the vehicle-mounted screens to adjust to the target screen brightness level.

[0013] A further solution is that determining the current environmental brightness level includes: quantizing the current environmental brightness into one level among a preset X environmental brightness levels;

[0014] And in step S103, the target fill light brightness level is selected from a preset N fill light brightness levels; in step S104, the target screen brightness level is selected from a preset M screen brightness levels, where N and M are positive integers less than X, and N may or may not be equal to M.

[0015] A further solution is that steps S105 and S106 are executed simultaneously or sequentially.

[0016] A further solution is that after executing steps S105 and S106, it further includes the step of triggering the camera to perform an automatic exposure adjustment once.

[0017] A further solution is that steps S101 to S106 are repeatedly executed at a preset time period, and the length of the preset time period is 10 seconds to 30 seconds.

[0018] A further solution is that the vehicle-mounted screen includes at least one of a central control screen, an instrument screen, a station section screen, and a passenger information screen.

[0019] A further solution is that in the step S105, the duty cycle of the PWM signal is adjusted to control the supplementary light LED array to be adjusted to the target supplementary light brightness level.

[0020] A further solution is that when the camera is in a non - working state or an idle state, the supplementary light operation of the supplementary light LED array is stopped.

[0021] In a second aspect, an in - vehicle interior supplementary light control system based on a camera provided by an embodiment of the present application includes: a camera configured to capture an image and provide an exposure value of the current in - vehicle environment;

[0022] a supplementary light LED array whose brightness can be controlled;

[0023] at least one in - vehicle screen whose brightness can be controlled;

[0024] a controller communicatively connected to the camera, the supplementary light LED array, and at least one of the in - vehicle screens; wherein, the controller is configured to execute the in - vehicle interior supplementary light control method according to any embodiment of the first aspect.

[0025] A further solution is that the controller includes a processor and a memory, and instructions are stored in the memory, and when the instructions are executed by the processor, the controller executes the in - vehicle interior supplementary light control method according to any embodiment of the first aspect.

[0026] The in - vehicle interior supplementary light control method and system designed in the present application determine the brightness of the in - vehicle environment by using the exposure value of the camera itself, and accordingly automatically adjust the brightness of the supplementary light LED array and the in - vehicle screen, effectively improving the imaging quality and stability of the in - vehicle camera in low - light and variable - light environments; this method not only solves the problem of insufficient effect of traditional automatic exposure under low illuminance and the inability of simple supplementary light methods to intelligently adapt to the environment, but also considers the impact of the in - vehicle screen on imaging and incorporates it into unified control, and supplements the exposure adjustment of the camera itself after the main light environment is adjusted, thereby providing a clearer and more reliable image input basis for applications such as in - vehicle face recognition and status monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a flowchart of an in - vehicle interior supplementary light control method provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following describes the preferred embodiments of the present application with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only for the purpose of illustration and explanation of the present application, and are not used to limit the present application.

[0029] In a first aspect, an embodiment of the present application provides a method for controlling internal vehicle supplementary lighting based on a camera, which can be applied to a monitoring system inside a vehicle. This method can be executed by a vehicle-mounted controller, such as an intelligent cockpit domain controller.

[0030] As Figure 1 shown, the method includes the following steps:

[0031] S101. Start the camera to make it in a working state, and obtain the current exposure value of the camera. Specifically, when an application that depends on the in-vehicle camera needs to be enabled, the vehicle-mounted controller sends a command to the target camera to make it enter the working state. The image signal processor (ISP) built into the camera determines a set of exposure parameters, such as shutter time, aperture value, gain / ISO, etc., according to the current shooting environment and its own automatic exposure (AE) algorithm, and calculates the current exposure value (EV) based on these parameters or scene brightness analysis.

[0032] S102. Based on the preset sensitivity characteristic of the camera, determine the current environmental brightness level of the vehicle interior according to the current exposure value. Specifically, after the controller receives the current exposure value EV reported by the camera, it needs to combine the sensitivity (SV) characteristic of this camera to determine the current environmental brightness (BV). In a specific implementation, the sensitivity of each camera is fixed. The reference sensitivity value SV of this model of camera is pre-stored in the memory of the controller, and calculations are performed according to the definite functional relationship EV = F(BV, SV) among the exposure value (EV), environmental brightness (BV), and sensitivity (SV).

[0033] Further, the determining the current environmental brightness level includes: quantifying the current environmental brightness into one of the preset X environmental brightness levels. For example, it can be preset that X = 16 brightness levels, and each level corresponds to a brightness value range. The controller determines the current specific environmental brightness level according to which range the calculated brightness value falls into.

[0034] S103. Based on a preset first correspondence, determine the target supplementary lighting brightness level of a supplementary lighting LED array according to the current environmental brightness level. The first correspondence is an inverse correspondence between the environmental brightness level and the target supplementary lighting brightness level. Specifically, a look-up table or a function is pre-stored inside the controller, and this look-up table or function defines the correspondence between the environmental brightness level determined in step S102 and the brightness level of the supplementary lighting LED array. This relationship is inverse, that is, the lower the environmental brightness level (the darker the environment), the higher the corresponding LED target supplementary lighting brightness level; conversely, the higher the environmental brightness level (the brighter the environment), the lower the corresponding LED target supplementary lighting brightness level, or even in a closed state (such as level 0).

[0035] Optionally, as described in a further solution, in this step, the controller queries a preset first correspondence (lookup table or function) according to the determined environmental brightness level (e.g., "Level 5"), and the obtained target fill light brightness level is one selected from N preset fill light brightness levels. For example, if N = 16 preset fill light brightness levels (from level 0 to level 15) are set, the query result may indicate that the target fill light brightness level is "Level 10".

[0036] S104. Based on a preset second correspondence, determine the target screen brightness level of at least one vehicle-mounted screen according to the current environmental brightness level. The second correspondence is a positive correspondence between the environmental brightness level and the target screen brightness level. Similar to S103, the controller also pre-stores a second lookup table or function that defines the correspondence between the environmental brightness level and the vehicle-mounted screen brightness level inside. This relationship is positive, that is, the higher the environmental brightness level, the higher (or the higher value is maintained) the corresponding target screen brightness level can be; the lower the environmental brightness level, the lower the corresponding target screen brightness level should be (to reduce interference with imaging in a dark environment or avoid affecting driving).

[0037] Optionally, as described in a further solution, in this step, the controller queries the preset second correspondence according to the determined environmental brightness level (e.g., "Level 5"), and the obtained target screen brightness level is one selected from M preset screen brightness levels. For example, if M = 16 preset screen brightness levels (from level 0 to level 15) are set, the query result may indicate that the target screen brightness level is "Level 3". Here, N and M can be the same value (e.g., both are 16), or different values (e.g., N = 16, M = 8), and generally the magnitudes of N and M are less than or equal to the number X of environmental brightness levels.

[0038] S105. Control the fill light LED array to adjust to the target fill light brightness level. The controller sends the determined target fill light brightness level (e.g., "Level 10") to the drive module of the fill light LED array through a control instruction. In a specific embodiment, this control instruction can be sent through the LIN bus or the CAN bus, or directly controlled through the GPIO port.

[0039] S106. Control at least one of the vehicle-mounted screens to adjust to the target screen brightness level. The controller sends the determined target screen brightness level (e.g., "Level 3") to the ECU responsible for controlling the corresponding screen brightness through a control instruction. After receiving the instruction, the ECU adjusts the backlight drive circuit of the corresponding screen to make the screen brightness reach the target level. In this embodiment, the vehicle-mounted screen includes at least one or more of the central control screen, the instrument screen, the station section screen, and the passenger information screen.

[0040] In some embodiments, steps S105 and S106 are executed simultaneously or sequentially.

[0041] In some embodiments, after executing steps S105 and S106, the method further includes the step of triggering the camera to perform an automatic exposure adjustment once. After the fill light LED array and the in-vehicle screen brightness are adjusted stably, the controller can send a trigger signal to the camera, or rely on the camera's own AE loop mechanism to make the camera recalculate and adjust the internal automatic exposure parameters (shutter, aperture, gain, etc.) again in the new and optimized lighting environment to obtain the final best image exposure effect.

[0042] In some embodiments, steps S101 to S106 are repeatedly executed at a preset time period, and the length of the preset time period is 10 seconds to 30 seconds. In a specific embodiment, a timer is maintained inside the controller. For example, the complete process from obtaining the EV to controlling the light / screen brightness is re-executed every 15 seconds to continuously adapt to the change of ambient light during vehicle driving.

[0043] In some embodiments, in step S105, the fill light LED array is controlled to be adjusted to the target fill light brightness level by adjusting the duty cycle of the PWM signal. By adjusting the duty cycle of the PWM (pulse width modulation) signal driving the fill light LED array, the LED array emits a light intensity corresponding to the target brightness level. For example, "level 10" corresponds to a PWM signal with a duty cycle of 62.5%.

[0044] In some embodiments, when the camera is in a non-working state or an idle state, the fill light operation of the fill light LED array is stopped to save energy and avoid unnecessary light emission.

[0045] In a second aspect, an embodiment of the present application provides an in-vehicle interior fill light control system based on a camera, including: a camera configured to capture an image and provide an exposure value of the current in-vehicle environment;

[0046] a fill light LED array whose brightness can be controlled;

[0047] at least one in-vehicle screen whose brightness can be controlled;

[0048] A controller, communicatively connected to the camera, the fill light LED array, and at least one of the vehicle-mounted screens; wherein, the controller is configured to execute the camera-based vehicle interior fill light control method according to any embodiment of the first aspect. Specifically, the controller includes a processor and a memory, and instructions are stored in the memory. When the instructions are executed by the processor, the controller executes the vehicle interior fill light control method according to any embodiment of the first aspect.

[0049] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working process of the above-described system can refer to the corresponding process in the foregoing method embodiments, and will not be elaborated herein.

[0050] The camera-based vehicle interior fill light control method and system provided in this embodiment determine the brightness of the vehicle interior environment by using the exposure value of the camera itself, and accordingly automatically adjust the brightness of the fill light LED array and the vehicle-mounted screen, effectively improving the imaging quality and stability of the vehicle interior camera in low-light and variable light environments; this method not only solves the problem of insufficient effect of traditional automatic exposure under low illuminance and the inability of simple fill light methods to intelligently adapt to the environment, but also considers the impact of the vehicle interior screen on imaging and incorporates it into unified control, supplemented by the camera's own exposure adjustment after the main light environment is adjusted, thus providing a clearer and more reliable image input basis for applications such as vehicle-mounted face recognition and status monitoring.

[0051] In the description of this application, it should be noted that the orientation or positional relationship indicated by the terms "vertical", "upper", "lower", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0052] In the description of this application, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0053] Finally, it should be noted that the above are only the preferred embodiments of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A camera-based interior vehicle light compensation control method, characterized in that, It includes the following steps: S101. Start the camera to make it in the working state, and obtain the current exposure value of the camera; S102. Based on the preset sensitivity characteristic of the camera, determine the current environmental brightness level of the vehicle interior according to the current exposure value; S103. Based on a preset first correspondence, determine the target supplementary light brightness level of a supplementary light LED array according to the current environmental brightness level, and the first correspondence is an inverse correspondence between the environmental brightness level and the target supplementary light brightness level; S104. Based on a preset second correspondence, determine the target screen brightness level of at least one in-vehicle screen according to the current environmental brightness level, and the second correspondence is a direct correspondence between the environmental brightness level and the target screen brightness level; S105. Control the supplementary light LED array to adjust to the target supplementary light brightness level; S106. Control at least one of the in-vehicle screens to adjust to the target screen brightness level.

2. The method for controlling interior light compensation of a vehicle based on a camera according to claim 1, wherein The determination of the current environmental brightness level includes: quantifying the current environmental brightness into one level among preset X environmental brightness levels; And in step S103, the target supplementary light brightness level is selected from preset N supplementary light brightness levels; in step S104, the target screen brightness level is selected from preset M screen brightness levels, where N and M are less than X and are positive integers, and N may or may not be equal to M.

3. The method for controlling interior light compensation of a vehicle based on a camera according to claim 1, characterized in that, Steps S105 and S106 are executed simultaneously or sequentially.

4. The method for controlling interior supplementary lighting of a vehicle based on a camera according to claim 1, characterized in that, After executing steps S105 and S106, it further includes the step: triggering the camera to perform an automatic exposure adjustment once.

5. The method for controlling interior light compensation of a vehicle based on a camera according to claim 1, characterized in that, Steps S101 to S106 are repeatedly executed at a preset time period, and the length of the preset time period is 10 seconds to 30 seconds.

6. The method for controlling interior light compensation of a vehicle based on a camera according to claim 1, characterized in that, The in-vehicle screen includes at least one of a center control screen, an instrument screen, a station section screen, and a passenger information screen.

7. The method for controlling interior light supplementation of a vehicle based on a camera according to claim 1, wherein In step S105, the supplementary light LED array is controlled to adjust to the target supplementary light brightness level by adjusting the duty cycle of the PWM signal.

8. The method for controlling interior supplementary lighting of a vehicle based on a camera according to claim 1, characterized in that, When the camera is in a non-working state or an idle state, stop the supplementary light operation of the supplementary light LED array.

9. A camera-based interior vehicle supplementary lighting control system, characterized in that, It includes: A camera configured to capture images and provide the exposure value of the current vehicle interior environment; A supplementary light LED array whose brightness can be controlled; At least one in-vehicle screen whose brightness can be controlled; A controller communicatively connected to the camera, the supplementary light LED array, and at least one of the in-vehicle screens; wherein, the controller is configured to execute the in-vehicle supplementary light control method based on the camera as described in any one of claims 1 to 8.

10. The camera-based vehicle interior supplementary lighting control method and system according to claim 9, characterized in that, The controller includes a processor and a memory, and instructions are stored in the memory. When the instructions are executed by the processor, the controller executes the in-vehicle supplementary light control method as described in any one of claims 1 to 8.

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