Detection method and device for detecting power-on blank screen of vehicle-mounted instrument

Abstract

The invention provides a method and a device for detecting a power-on blank screen of a vehicle-mounted instrument. The method comprises the following steps: acquiring a standard blank screen image of the instrument; controlling the instrument to execute a power-on operation of a preset cycle number, and collecting a real-time instrument image after each power-on; the similarity between the real-time instrument image and the instrument blank screen image in each cycle is calculated, if the similarity exceeds a preset threshold value, the instrument in the current cycle is marked as a blank screen state, and if the similarity does not exceed the preset threshold value, marking is not carried out; counting the cycle index of the instrument marked as the blank screen state, and if the cycle index exceeds an allowable threshold, generating a blank screen fault report; and if the number of cycles does not exceed the allowable threshold, generating an instrument normal report. Through power-on operation with a preset cycle number, repeated cycle power-on rather than single detection covers accidental faults. Transient anomalies and persistent faults are distinguished through statistics, manual intervention is reduced, the detection period is shortened, and meanwhile unnecessary follow-up testing and correction cost after misjudgment is avoided.

Description

Technical Field

[0001] The present application relates to the field of image recognition and processing technology, and in particular to a method and device for detecting a black screen when a vehicle instrument is powered on. Background Art

[0002] In the field of vehicle instrument black screen detection, traditional methods typically use single power-on detection. This involves capturing an image once without processing it and directly comparing it with a reference image to determine the result. However, this method has the following drawbacks:

[0003] (1) Black screen problems are often caused by occasional factors such as power fluctuations and software crashes, and single detection is prone to misjudgment. If the fault only occurs briefly under specific conditions such as high-temperature startup, a single test may misjudge it. Subsequent unnecessary testing and corrections based on this judgment will waste time and increase costs.

[0004] (2) Traditional methods often ignore the precise matching of the image acquisition area and the display screen pixels, resulting in inaccurate similarity calculation results. Specifically, if the image pixels for detection and comparison are inconsistent, forced scaling is required during image processing, resulting in pixel value distortion. After scaling, the image edges are blurred and details are lost, and the normal display is mistakenly judged as a black screen, reducing the detection accuracy. Summary of the Invention

[0005] The embodiments of the present application provide a method and device for detecting a black screen when a vehicle instrument is powered on, so as to solve the problem in the related art that in the black screen detection of a vehicle instrument, a single power-on detection may encounter a normal short black screen caused by occasional factors such as power fluctuations, resulting in a high misjudgment rate.

[0006] In a first aspect, a method for detecting a black screen when a vehicle-mounted instrument is powered on is provided, comprising: controlling the instrument to perform power on and off operations according to a preset number of cycles, wherein the instrument completes the operation in a single power on and power off sequence, which is recorded as one cycle; collecting a real-time instrument image after each power-on of the instrument; calculating the similarity between the real-time instrument image and a standard black screen image in each cycle, if the similarity exceeds a preset threshold, the instrument in the current cycle is in a black screen state, and the current cycle is marked; otherwise, it is not marked; counting the number of marked cycles, if the number exceeds an allowable threshold, generating a black screen fault report; otherwise, the instrument is normal.

[0007] In some embodiments, the acquisition of a standard black screen image and the collection of a real-time instrument image include the following steps:

[0008] When the instrument is in sleep or unpowered state, use the camera to capture a picture that covers the entire instrument screen and has the same pixels as the instrument screen as the standard black screen image;

[0009] Each time the instrument is powered on, a camera captures a picture containing the entire instrument screen and having the same pixels as the instrument screen as the real-time instrument image.

[0010] In some embodiments, each time the instrument is powered on and before collecting the real-time instrument image, the following steps are further included:

[0011] The first interval time is set according to the self-check time required before the instrument screen is displayed after the instrument is powered on; after each power-on, after waiting for the first interval time, the real-time instrument image is obtained through the camera.

[0012] In some embodiments, before calculating the similarity between the real-time instrument image and the standard black screen image in each cycle, grayscale processing is further performed on the real-time instrument image and the standard black screen image.

[0013] In some embodiments, grayscale processing is performed on the real-time instrument image and the standard black screen image, which includes the following steps:

[0014] Extract the pixel values ​​of the RGB channels of the real-time instrument image and the standard black screen image respectively; calculate the grayscale value of each pixel according to the first formula based on the brightness weighted average method;

[0015] Replace the RGB value of each pixel with the calculated grayscale value to generate a grayscale image containing only grayscale values.

[0016] In some embodiments, the generated black screen fault report includes the following contents:

[0017] The number of cycles marked, as well as the time and environmental parameters corresponding to the marked cycles; the environmental parameters include ambient temperature, light intensity and power supply voltage fluctuation range.

[0018] In some embodiments, after marking the current cycle, the process further includes classifying the black screen state of the instrument, which includes the following steps:

[0019] After determining that the instrument of the current cycle is in a black screen state, keep the instrument powered on, and read the instrument's wake-up state and obtain the BATT power supply connection status through the communication bus CAN; if the instrument is only connected to the BATT power supply and is in a dormant state, the black screen state of the current cycle is determined to be a black screen without backlight; if the instrument is only connected to the BATT power supply and is in an awake state, the black screen state of the current cycle is determined to be a black screen with backlight.

[0020] In some embodiments, after classifying the black screen status of the instrument, the method further includes associating and recording the classified specific black screen status and its corresponding cycle number into the generated black screen fault report.

[0021] In some embodiments, the preset threshold is adjusted according to the ambient light intensity and the power supply voltage, which includes the following steps:

[0022] Real-time collection of light intensity and power supply voltage of the test environment;

[0023] Establish a mapping relationship table between light intensity, power supply voltage and preset threshold value based on historical test data;

[0024] Based on the light intensity and power supply voltage of the current test environment, a corresponding preset threshold is obtained from the mapping relationship table as the preset threshold of the current test environment.

[0025] In a second aspect, a device for detecting a black screen when a vehicle instrument is powered on is provided, comprising:

[0026] Image acquisition module, which is used to collect real-time instrument images every time the instrument is powered on;

[0027] An image processing module is used to control the instrument to power on and off according to a preset number of cycles, wherein the instrument completes the operation in a single power-on and power-off sequence, which is recorded as one cycle; and calculates the similarity between the real-time instrument image and the standard black screen image in each cycle. If the similarity exceeds a preset threshold, the instrument in the current cycle is in a black screen state and the current cycle is marked; otherwise, it is not marked;

[0028] The report generation module is used to count the number of marked cycles. If the number exceeds the allowed threshold, a black screen fault report is generated; otherwise, the instrument is normal.

[0029] The beneficial effects of the technical solutions provided in the embodiments of the present application include:

[0030] The embodiment of the present application provides a method and device for detecting a black screen when an on-board instrument is powered on, wherein, through a power-on operation with a preset number of cycles, multiple power-on cycles are performed instead of a single detection, covering occasional faults, such as power fluctuations, software instantaneous crashes, and short black screens that are normal phenomena; if the black screen only appears in a specific cycle, multiple detections can filter out accidental anomalies, avoid unnecessary subsequent processing due to a single misjudgment, and reduce the black screen misjudgment rate; the number of cycles of marking the black screen state is accumulated and compared with the allowed threshold to determine whether the instrument is black, and statistical rules are used to distinguish short-term anomalies from persistent faults. A black screen report is generated after the automatic cycle operation, reducing manual intervention, shortening the detection cycle, and avoiding unnecessary subsequent testing and correction costs; it solves the problem in the related art that in the black screen detection of on-board instruments, a single power-on detection may encounter a normal short-term black screen caused by occasional factors such as power fluctuations, resulting in a high misjudgment rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1A schematic diagram of a simplified process for detecting a black screen on a vehicle instrument panel provided in an embodiment of the present application;

[0032] Figure 2 This is a complete flowchart of the method for detecting a black screen on a vehicle instrument panel provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] In order to make the technical problem to be solved by this application clearer, the causes of the technical problem will be specifically analyzed below.

[0035] The primary problem that this application aims to solve is the problem of occasional misjudgment of black screens. Traditional single power-on detection methods are prone to misjudging short black screens as faults due to occasional factors such as power supply fluctuations, instantaneous software crashes, and high-temperature startup anomalies, resulting in unnecessary subsequent testing and corrections, increasing time and costs; and occasional problems may only occur once in a single detection, and it is impossible to accurately capture the fault pattern through a single test. A single power-on can only reflect the instrument status at a certain moment and cannot cover different working conditions, such as cold start and stability performance under high-temperature operation; instantaneous environmental changes, such as sudden changes in light and electromagnetic interference may cause single image acquisition anomalies, and the normal display may be mistakenly judged as a black screen. Secondly, there's the issue of misjudgment caused by image acquisition errors. Traditional methods directly compare a single captured image with a reference image. This can lead to deviations in the similarity calculation due to lighting variations, screen reflections, or resolution differences, potentially misinterpreting a normal display as a black screen. Specifically, changes in ambient light or screen reflections can cause abnormal brightness in the captured image, resulting in significant differences when compared with the reference image. If the resolution or captured area of ​​the standard black screen image differs from that of the image under test, pixel alignment errors can directly affect the similarity calculation results. The instrument undergoes a self-test after powering on. If images are acquired before the self-test is complete, abnormal images from the initialization phase may be captured. Furthermore, there are issues with the efficiency and consistency of automated testing. Traditional methods rely on manual power-on and power-off operations and image acquisition, which is inefficient and difficult to maintain consistent test conditions, impacting the repeatability of results. Specifically, manual power-on and power-off sequencing and image acquisition timing can introduce human errors, leading to fluctuations in test conditions. This makes it impossible to automatically perform multiple test cycles and fails to simulate long-term reliability scenarios. There is also a problem of insufficient fault diagnosis and classification. Traditional methods only determine whether the screen is black or not, without distinguishing the type of fault, such as power supply problems or display driver failures, resulting in low maintenance efficiency. Specifically, the root cause of the black screen cannot be located without combining parameters such as the instrument power supply mode and wake-up status; the environmental parameters when the fault occurs, such as temperature and voltage, are not recorded, making it difficult to analyze the causes of occasional faults.

[0036] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0037] In the first aspect, the embodiment of the present application provides a method for detecting a black screen on a vehicle instrument. Figure 1 , Figure 1 This is a brief flow chart of the method for detecting a black screen on a vehicle instrument provided in an embodiment of the present application. Figure 1 As shown, a method for detecting a black screen when a vehicle instrument is powered on includes:

[0038] S1. Control the instrument to power on and off according to the preset number of cycles. The instrument completes the operation in the order of powering on and off once, which is recorded as one cycle.

[0039] S2. After each power-on of the instrument, a real-time instrument image is collected; the similarity between the real-time instrument image and the standard black screen image in each cycle is calculated. If the similarity exceeds a preset threshold, the instrument in the current cycle is in a black screen state and the current cycle is marked; otherwise, no mark is made;

[0040] S3. Count the number of marked cycles. If the number exceeds an allowable threshold, generate a black screen fault report; otherwise, the instrument is normal.

[0041] This detection method is designed to cover occasional faults such as power fluctuations and software crashes, which result in brief black screens but are normal phenomena, by powering on for a preset number of cycles. If the black screen only appears in a specific cycle, multiple detections can filter out occasional anomalies, avoid unnecessary subsequent processing due to a single misjudgment, and reduce the black screen misjudgment rate. The cumulative number of cycles in which the black screen state is marked is compared with the allowed threshold to determine whether the instrument is black. Statistical rules are used to distinguish between brief anomalies and persistent faults, and a black screen report is generated after the automatic cycle operation, reducing manual intervention, shortening the detection cycle, and avoiding unnecessary subsequent testing and correction costs. This method solves the problem in the related technology of vehicle instrument black screen detection that a single power-on detection may encounter a normal brief black screen caused by sporadic factors such as power fluctuations, resulting in a high misjudgment rate.

[0042] In some preferred embodiments, the acquisition of the standard black screen image and the collection of the real-time instrument image include the following steps:

[0043] When the instrument is in sleep or unpowered state, the camera captures a picture covering the entire instrument screen and having the same pixels as the instrument screen as the standard black screen image; each time the instrument is powered on, the camera captures a picture containing the entire instrument screen and having the same pixels as the instrument screen as the real-time instrument image.

[0044] In this embodiment, the pixel size of the real-time instrument image, the standard black screen image, and the instrument screen is kept uniform, eliminating deviations in the similarity calculation value during black screen determination due to pixel inconsistency and improving reliability. Traditional image acquisition methods have the following issues: Only a partial screen area is captured, resulting in an incomplete representation of the black screen state; the resolution of the standard image and the image to be measured is inconsistent, causing deviations in the similarity calculation. Therefore, the acquisition method of the standard black screen image and the real-time instrument image is restricted. By fully capturing the screen and enforcing pixel consistency, the physical range and technical parameters of the image comparison are fully aligned, eliminating misjudgments due to regional or resolution differences.

[0045] In some preferred embodiments, each time the instrument is powered on and before collecting the real-time instrument image, the following steps are further included:

[0046] The first interval time is set according to the self-check time required before the instrument screen is displayed after the instrument is powered on; after each power-on, the real-time instrument image is obtained through the camera after waiting for the first interval time.

[0047] In this embodiment, the instrument needs to go through a self-test process after being powered on. If an image is captured before the self-test is completed, the screen may be in an initialization state, such as a brief black screen or flickering, leading to misjudgment. The self-test time of different instrument models is different, and a fixed waiting time may not be adaptable to all scenarios. Therefore, after the instrument is powered on, a first interval time is set according to its self-test time, and the image to be tested is captured after waiting for this time after each power-on. The waiting interval is set according to the actual self-test time to ensure that the instrument has entered a stable display state when the image is captured; to avoid abnormal screen states during the self-test process, such as an initial black screen, being mistakenly marked as a fault; to adapt to the differences in self-test time lengths of different instrument models, and to enhance the versatility of the method.

[0048] In some preferred embodiments, before calculating the similarity between the real-time instrument image and the instrument black screen image in each cycle, the real-time instrument image and the instrument black screen image are further grayscaled.

[0049] In this embodiment, color images are susceptible to changes in ambient lighting, such as color temperature differences or screen reflections, which can lead to deviations in similarity calculations. Furthermore, color image processing requires the calculation of multi-channel data, increasing computing resource consumption. Therefore, the standard black screen image and the real-time instrument image are grayscaled before similarity calculations. After grayscale conversion, only the brightness information is retained, reducing the impact of color changes on the similarity calculation. Single-channel data processing reduces computational effort, making it suitable for scenarios with high real-time requirements and increasing algorithm robustness. This is reflected in the more stable structural similarity judgments made by the SSIM algorithm on grayscale images.

[0050] In some preferred embodiments, grayscale processing is performed on the real-time instrument image and the standard black screen image, which includes the following steps:

[0051] Extract the pixel values ​​of the RGB channels of the real-time instrument image and the standard black screen image respectively; calculate the grayscale value of each pixel according to the first formula based on the brightness weighted average method; replace the RGB value of each pixel with the calculated grayscale value to generate a grayscale image containing only grayscale values.

[0052] In this embodiment, the first formula is: Gray = 0.299 × R + 0.587 × G + 0.114 × B; where R, G, and B represent the pixel values ​​of the red, green, and blue channels, respectively, and Gray represents the converted grayscale value. Grayscale conversion is performed based on the human eye's sensitivity to different colors. The human eye is most sensitive to green (G), followed by red (R), and least sensitive to blue (B). This formula simulates this physiological characteristic through weighting coefficients. Compared to the simple average method (Gray = (R + G + B) / 3), this method generates a grayscale image that better matches the actual brightness distribution perceived by the human eye, avoiding brightness distortion caused by improper color weighting. This improves the accuracy of similarity calculations between real-time images and standard black screen images. Furthermore, by converting color images into single-channel grayscale images, interference from color information, color temperature differences, and screen reflections on similarity calculations is effectively eliminated. Grayscaling simplifies a three-channel RGB image into single-channel data, significantly reducing the computational complexity of image processing.

[0053] In some preferred embodiments, the generated black screen fault report includes the following contents: the number of marked cycles, and the time and environmental parameters corresponding to the marked cycles; environmental parameters include ambient temperature, light intensity and power supply voltage fluctuation range.

[0054] In this embodiment, traditional reports only record the results and lack contextual data about the failure, such as environmental conditions. It is impossible to analyze whether the black screen is caused by specific environmental factors, such as high temperature or unstable voltage. Therefore, it is stipulated that the black screen failure report must include: the number of cycles to determine the black screen and the corresponding timestamp. This includes environmental parameters such as temperature, light intensity, and power supply voltage fluctuations. By correlating environmental parameters with the time of failure, it helps to locate the root cause of sporadic failures. For example, if the black screen often occurs in a high-temperature environment, the thermal design verification can be strengthened in a targeted manner, and a complete test log can be provided for the reliability certification of the vehicle instrument.

[0055] In some preferred embodiments, after marking the current cycle, the process further includes classifying the black screen state of the instrument, which includes the following steps:

[0056] After determining that the instrument of the current cycle is in a black screen state, keep the instrument powered on, and read the instrument's wake-up state and the connection status of the BATT power supply through the communication bus CAN;

[0057] If the instrument is only connected to the BATT power supply and is in sleep mode, the black screen state of the current cycle is determined to be a black screen without backlight;

[0058] If the instrument is only connected to the BATT power supply and is in the awake state, the black screen state of the current cycle is determined to be a black screen with backlight.

[0059] In this embodiment, traditional methods cannot distinguish the type of black screen, such as power failure or display module failure. Unclassified faults need to be manually checked one by one, increasing maintenance costs. Therefore, after determining that the screen is black, the power supply mode and wake-up status of the instrument are read through the CAN bus to distinguish between a black screen without backlight and a black screen with backlight. If the instrument is only connected to the BATT power supply and is in the dormant state, the black screen state of the current cycle is determined to be a black screen without backlight. If the instrument is only connected to the BATT power supply and is in the awake state, the black screen state of the current cycle is determined to be a black screen with backlight. After clarifying the fault type, the problem module can be quickly located, such as checking the power circuit or screen driver; and it provides a classification and statistical basis for subsequent reliability analysis.

[0060] In some preferred embodiments, after classifying the black screen status of the instrument, the method further includes associating and recording the classified specific black screen status and its corresponding cycle number into the generated black screen fault report.

[0061] In this embodiment, the traditional report only counts the number of black screen occurrences and does not record the specific fault type; it is unable to identify the occurrence pattern of specific fault types, such as frequent backlight failures under high temperatures; therefore, the classified black screen status, such as backlight and no backlight, and its association with the number of cycles are recorded in the fault report; through classification statistics, the distribution characteristics of different fault modes are identified; if a certain model of instrument frequently has a black screen with backlight, the display driver firmware can be optimized first, and the report format can be unified to facilitate data sharing and comparison across projects or teams.

[0062] In some preferred embodiments, the preset threshold is adjusted according to the ambient light intensity and the power supply voltage, which includes the following steps:

[0063] Real-time collection of light intensity and power supply voltage of the test environment;

[0064] Establish a mapping relationship table between light intensity, power supply voltage and preset threshold value based on historical test data;

[0065] Based on the light intensity and power supply voltage of the current test environment, a corresponding preset threshold is obtained from the mapping relationship table as the preset threshold of the current test environment.

[0066] In this embodiment, the traditional method uses a fixed threshold, which cannot adapt to the impact of different environments on image acquisition, resulting in deviations in similarity calculations. In addition, instantaneous voltage drops or sudden changes in illumination may cause single image anomalies, and the fixed threshold cannot distinguish between occasional interference and real faults. Therefore, an optimization method for dynamically adjusting the preset threshold is proposed. During the test process, the sensor obtains the current environment's light intensity and power supply voltage data in real time. Based on historical test data, a mapping relationship table of light intensity-power supply voltage-threshold is constructed. According to the current environmental parameters, the optimal threshold is matched from the mapping table for similarity determination in the current test cycle. The optimal threshold is automatically selected based on the real-time environmental parameters. By analyzing historical test data, a quantitative relationship between environmental parameters and thresholds is established, maintaining high detection accuracy even in extreme or fluctuating environments.

[0067] In a second aspect, an embodiment of the present application further provides a device for detecting a black screen when a vehicle instrument is powered on, comprising:

[0068] An image acquisition module is used to collect real-time instrument images after each power-on of the instrument; an image processing module is used to control the power-on and power-off operations of the instrument according to a preset number of cycles, wherein the instrument completes the operation in the order of single power-on and power-off, which is recorded as one cycle; and calculates the similarity between the real-time instrument image and the standard black screen image in each cycle. If the similarity exceeds a preset threshold, the instrument in the current cycle is in a black screen state and the current cycle is marked; otherwise, it is not marked; a report generation module is used to count the number of marked cycles. If the number exceeds the allowable threshold, a black screen fault report is generated; otherwise, the instrument is normal.

[0069] In this device, the camera uses a USB-controlled, high-definition fixed camera with pixels no less than those of the LCD instrument. This has the advantage of simple and convenient communication, and can capture instrument pixels in real time in high definition without distortion. Non-fixed devices are not selected to reduce external environmental interference. If non-fixed cameras are used to capture images, they will be significantly affected by environmental interference, which is not conducive to subsequent similarity comparison. All relays are linked to the DBC database CANoe or vTESTstudio to indirectly control the relays. This has the advantage of CAN communication, which is consistent with the communication method between the instrument under test and the test tool, and is easy to control. Traditional methods rely on multiple independent tools such as cameras, control software, and data analysis tools. They have low integration and require manual tool switching and intermediate data processing, which is prone to errors and inefficient. Therefore, an image acquisition module is proposed to capture standard black screen images and the image under test; an image processing module to perform grayscale processing and similarity calculation; and a report generation module to compile statistics and generate reports. Image acquisition, processing, and result output functions are integrated to reduce external dependencies.

[0070] The beneficial effects brought about by the present invention include:

[0071] Provided are a method and device for detecting a black screen when an on-board instrument is powered on. In the method, a power-on operation with a preset number of cycles is performed, and multiple power-on cycles are performed instead of a single detection, thereby covering occasional faults, such as power fluctuations and software crashes, which are short black screens but normal phenomena. If the black screen only appears in a specific cycle, multiple detections can filter out occasional anomalies, avoid unnecessary subsequent processing due to a single misjudgment, and reduce the black screen misjudgment rate. The number of cycles in which the black screen state is marked is accumulated and compared with the allowed threshold to determine whether the instrument is black, distinguish short-term anomalies from persistent faults through statistical laws, and generate a black screen report after the automatic cycle operation, thereby reducing manual intervention, shortening the detection cycle, and avoiding unnecessary subsequent testing and correction costs. The method solves the problem in the related art that in the black screen detection of on-board instruments, a single power-on detection may encounter a normal short-term black screen caused by occasional factors such as power fluctuations, resulting in a high misjudgment rate.

[0072] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0073] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0074] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0075] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0076] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0077] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of the present application.

[0078] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for detecting a black screen when a vehicle instrument is powered on, characterized in that: It includes: Control the instrument to power on and off according to the preset number of cycles. The instrument completes the operation in the order of power on and off once, which is recorded as one cycle. The real-time instrument image is collected each time the instrument is powered on; the similarity between the real-time instrument image and the standard black screen image in each cycle is calculated. If the similarity exceeds the preset threshold, the instrument in the current cycle is in black screen state and the current cycle is marked; otherwise, no mark is made; The number of marked cycles is counted, and if the number exceeds an allowable threshold, a black screen fault report is generated; otherwise, the instrument is normal.

2. The method for detecting a black screen when a vehicle instrument is powered on according to claim 1, wherein: The acquisition of the standard black screen image and the collection of the real-time instrument image include the following steps: When the instrument is in a dormant or unpowered state, a picture covering the entire instrument screen and having the same pixels as the instrument screen is captured by a camera as the standard black screen image; Each time the meter is powered on, a picture containing the complete meter screen and having the same pixels as the meter screen is captured by the camera as the real-time meter image.

3. The method for detecting a black screen when a vehicle instrument is powered on according to claim 2, wherein: Each time the instrument is powered on and before collecting the real-time instrument image, the following steps are also included: Set the first interval time according to the self-test time required before the instrument screen displays after the instrument is powered on; After each power-on, the real-time instrument image is acquired through the camera after waiting for the first interval time.

4. The method for detecting a black screen when a vehicle instrument is powered on according to claim 1, wherein: Before calculating the similarity between the real-time instrument image and the standard black screen image in each cycle, the real-time instrument image and the standard black screen image are also grayscaled.

5. The method for detecting a black screen when a vehicle instrument is powered on according to claim 1, wherein: Grayscale processing is performed on the real-time instrument image and the standard black screen image, which includes the following steps: Extract the pixel values ​​of the RGB three channels of the real-time instrument image and the standard black screen image respectively; Based on the brightness weighted average method, the grayscale value of each pixel is calculated according to the first formula; Replace the RGB value of each pixel with the calculated grayscale value to generate a grayscale image containing only grayscale values.

6. The method for detecting a black screen when a vehicle instrument is powered on according to claim 1, wherein: The generated black screen fault report includes the following contents: The number of cycles marked, as well as the time and environmental parameters corresponding to the marked cycles; the environmental parameters include ambient temperature, light intensity and power supply voltage fluctuation range.

7. The method for detecting a black screen when a vehicle instrument is powered on according to claim 1, wherein: After marking the current cycle, the instrument black screen state is also classified, which includes the following steps: After determining that the instrument of the current cycle is in a black screen state, keep the instrument powered on, and read the instrument's wake-up state and the connection status of the BATT power supply through the communication bus CAN; If the instrument is only connected to the BATT power supply and is in sleep mode, the black screen state of the current cycle is determined to be a black screen without backlight; If the instrument is only connected to the BATT power supply and is in the awake state, the black screen state of the current cycle is determined to be a black screen with backlight.

8. The method for detecting a black screen when a vehicle instrument is powered on according to claim 7, wherein: After classifying the black screen status of the instrument, the method also includes associating and recording the classified specific black screen status and its corresponding cycle number into the generated black screen fault report.

9. The method for detecting a black screen when a vehicle instrument is powered on according to claim 1, wherein: The preset threshold is adjusted according to the ambient light intensity and the power supply voltage, which includes the following steps: Real-time collection of light intensity and power supply voltage of the test environment; Establish a mapping relationship table between light intensity, power supply voltage and preset threshold value based on historical test data; Based on the light intensity and power supply voltage of the current test environment, a corresponding preset threshold is obtained from the mapping relationship table as the preset threshold of the current test environment.

10. A device for detecting a black screen when a vehicle instrument is powered on, characterized in that: It includes: Image acquisition module, which is used to collect real-time instrument images every time the instrument is powered on; An image processing module is used to control the instrument to power on and off according to a preset number of cycles, wherein the instrument completes the operation in a single power-on and power-off sequence, which is recorded as one cycle; and calculates the similarity between the real-time instrument image and the standard black screen image in each cycle. If the similarity exceeds a preset threshold, the instrument in the current cycle is in a black screen state and the current cycle is marked; otherwise, it is not marked; The report generation module is used to count the number of marked cycles. If the number exceeds the allowed threshold, a black screen fault report is generated; otherwise, the instrument is normal.

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