Electronic rearview mirror control system based on functional safety and control method thereof

Abstract

The application belongs to the field of automobile control, and particularly relates to an electronic rearview mirror control system based on functional safety and a control method thereof. The electronic rearview mirror system comprises three parts: a sensor, a controller and an actuator; and different fault types obtained based on functional safety HAZOP analysis are used for corresponding fault processing. The application uses redundant cameras to ensure high reliability and high safety of the electronic rearview mirror, and can also ensure certain rearview function when the electronic rearview mirror camera fails. Based on functional safety analysis, the safety target and ASIL level of the electronic rearview mirror system are obtained, and safety requirements are derived. The application is based on functional safety design, effectively improves the safety performance of the system, and provides an auxiliary field of vision when the electronic rearview mirror system fails, which can avoid the situation of complete lack of vision when the system fails to a certain extent.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of automobile control, and particularly relates to an electronic rearview mirror control system based on functional safety and a control method thereof. BACKGROUND

[0002] With the development of vehicle intelligence, the disadvantages of traditional rearview mirrors, such as poor vision caused by foggy and rainy weather, insufficient light and frequent light and dark alternation, are solved through the popularization of electronic rearview mirrors. Electronic rearview mirrors capture images around the vehicle through cameras and transmit them to the display screen in real time for the driver to watch, thereby greatly expanding the field of vision and eliminating blind spots. However, the existing electronic rearview mirror vision display control system still has some deficiencies in module integration, data transmission and function perfection. However, as an important safety-related system, electronic rearview mirrors generate unacceptable risks due to system and random failures because of the inherent nature of the electrical system. For example, some systems cause image display delay or distortion due to poor communication between modules or insufficient data processing capacity; some systems have multiple functions, but the operation is complex and not user-friendly, which affects the driving experience of the driver. At present, the risk caused by system or random failure of electronic rearview mirrors is increasing day by day, and the electronic rearview mirror cannot continue to provide effective vision after failure. SUMMARY

[0003] To solve the above problems, the present application uses the cabin controller as the electronic rearview mirror controller on the basis of cabin-parking integrated design, and uses the parking auxiliary rear camera and the cabin central control screen, to provide an electronic rearview mirror control system and a control method thereof according to functional safety, which still retains part of the vision when the electronic rearview mirror system fails, and improves the safety of the system. The specific technical solutions are as follows:

[0004] An electronic rearview mirror control system based on functional safety, which includes three parts: sensors, controllers and actuators; the sensors include a left electronic rearview mirror camera, a right electronic rearview mirror camera and a rear camera; the controller is provided with a function control module and an image processing module; the actuator is provided with a central control screen, a left electronic rearview mirror screen and a right electronic rearview mirror screen; the sensors transmit the collected images to the controller, which outputs the images to the left and right electronic rearview mirror screens after image processing.

[0005] Further, the controller can also be provided with a watchdog module.

[0006] The control method of the foregoing control system includes determining functional safety requirements and fault analysis and processing.

[0007] The determination of functional safety requirements includes:

[0008] (1) Confirm the fault mode, including electronic rearview mirror imaging delay or jam, electronic rearview mirror imaging reversal, left and right electronic rearview mirror imaging inversion (left display right, right display left), electronic rearview mirror imaging incompleteness or loss;

[0009] (2) According to the requirements of ISO 26262 functional safety standard, from controllability C, severity S, exposure E three aspects combined with the main operation scene of function, HARA analysis is carried out to determine the safety target and ASIL level, and the safety target SG is obtained;

[0010] (3) According to the safety target SG analyzed by HARA, the functional safety requirement FSR is derived through fault tree FTA analysis;

[0011] The fault analysis and processing body steps are:

[0012] (1) Through the perception fusion technology, the imaging of the rear camera and the imaging of the left and right electronic rearview mirror cameras are mutually verified to determine whether the camera imaging of the electronic rearview mirror system is correct;

[0013] (2) If they are consistent, it is judged that the function is normal;

[0014] (3) If it is detected that the left / right electronic rearview mirror camera imaging is inconsistent with the rear camera imaging, but the right / left electronic rearview mirror camera imaging is consistent with the rear camera imaging, it is judged that the left / right electronic rearview mirror camera is faulty, then the imaging of the rear camera is covered after being deformed by cutting, providing temporary vision for the driver, and warning the driver through the vehicle alarm system to remind the driver to find a nearby repair point for repair in time;

[0015] (4) If they are all inconsistent, then the rearview mirror camera imaging is displayed on the whole vehicle central control screen after processing, and the driver is warned through the vehicle alarm system to remind the driver to find a nearby repair point for repair in time.

[0016] Further, if the electronic rearview mirror controller is provided with a watchdog module, the watchdog module is used to monitor the main control module and the image processing module, and if a fault occurs, the controller is restarted by controlling the power module.

[0017] Further, the fault analysis and processing body steps further include:

[0018] (5) The controller back sampling actuator left and right electronic rearview mirror screen image is compared with the image collected by the rear camera through the perception fusion technology;

[0019] (6) If the unilateral comparison result is inconsistent, the inconsistent side electronic rearview mirror screen is cut off, the rear camera imaging is displayed on the whole vehicle central control screen after processing, the driver is alarmed through the vehicle alarm system, and the driver is reminded to find a nearby repair point in time for repair;

[0020] (7) If the bilateral comparison result is inconsistent, the rearview mirror camera imaging is displayed on the whole vehicle central control screen after processing, the driver is alarmed through the vehicle alarm system, and the driver is reminded to find a nearby repair point in time for repair.

[0021] The present application uses redundant cameras to ensure high reliability and high safety of the electronic rearview mirror, and can still ensure certain rearview function when the electronic rearview mirror camera fails. Based on functional safety analysis, the safety target and ASIL level of the electronic rearview mirror system are obtained, and the safety requirements are derived. The present application is based on functional safety design, which effectively improves the safety performance of the system, and provides an auxiliary field of view when the electronic rearview mirror system fails, which can to some extent avoid the situation of complete lack of field of view when the system fails. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The present application is an electronic rearview mirror control system structure schematic diagram;

[0023] Figure 2 The present application is a flowchart of determining functional safety requirements in the method;

[0024] Figure 3 The present application is a fault analysis flowchart. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0026] An electronic rearview mirror control system based on functional safety as shown in Figure 1 The electronic rearview mirror system includes three parts: a sensor, a controller and an actuator; the sensor includes a left electronic rearview mirror camera, a right electronic rearview mirror camera and a rear camera; the controller is provided with a function control module and an image processing module; the actuator is provided with a central control screen, a left electronic rearview mirror screen and a right electronic rearview mirror screen; the sensor transmits the collected images to the controller, and outputs the images to the left electronic rearview mirror screen and the right electronic rearview mirror screen after image processing by the controller. The controller can also be provided with a watchdog module.

[0027] The control method using the foregoing control system comprises determining functional safety requirements and failure analysis processing,

[0028] Wherein the determining of the functional safety requirements comprises:Specific processes are shown in Figure 2

[0029] (1) Confirming failure modes, including electronic rearview mirror imaging delay or sticking, electronic rearview mirror imaging reversal, left and right electronic rearview mirror imaging inversion (left display right, right display left), and electronic rearview mirror imaging incompleteness or loss;

[0030] (2) According to the requirements of the ISO 26262 functional safety standard, HARA analysis is performed from the controllability C, severity S, and exposure E three aspects in combination with the main operation scene of the function to determine the safety target and ASIL level, and the safety target SG is obtained, as shown in the following table.

[0031] SG Description ASIL Level FTTI SG1 Avoid unintended electronic rearview mirror imaging stuck B 1000ms SG2 Avoid unintended electronic rearview mirror imaging reversal B 1000ms SG3 Avoid unintended electronic rearview mirror imaging inversion A 1000ms SG4 Avoid unintended electronic rearview mirror imaging incomplete or missing QM -

[0032] (3) According to the safety target SG analyzed by the HARA, the functional safety requirements FSR are derived through the fault tree FTA analysis, as shown in the following table.

[0033] NO. Description ASIL Level FSR01 Left electronic rearview mirror camera shall send correct imaging information B FSR02 Right electronic rearview mirror camera shall send correct imaging information B FSR03 Rearview mirror camera shall send correct imaging information QM FSR04 Electronic rearview mirror controller shall be able to correctly process left and right electronic rearview mirror imaging B FSR05 Electronic rearview mirror controller shall be able to diagnose and process left and right electronic rearview mirror camera imaging failure B FSR06 Electronic rearview mirror controller shall send warning information to the driver if it diagnoses and processes left and right electronic rearview mirror camera imaging failure B FSR07 Electronic rearview mirror controller shall correctly process rear camera image and overlay the failed electronic rearview mirror camera imaging if it diagnoses left / right electronic rearview mirror camera failure. QM FSR08 Electronic rearview mirror controller shall correctly process rear camera image and display it on the vehicle central control screen if it diagnoses left and right electronic rearview mirror camera failure at the same time QM FSR09 Vehicle central control screen shall correctly display camera imaging QM FSR10 Left and right electronic rearview mirror display screens shall correctly display camera imaging B FSR11 Vehicle central control screen shall correctly display warning information B

[0034] The failure analysis processing steps are shown in the flow analysis schematic diagram Figure 3

[0035] (1) Through the perception fusion technology, the imaging of the rear camera and the imaging of the left and right electronic rearview mirror cameras are mutually verified to determine whether the camera imaging of the electronic rearview mirror system is correct.

[0036] (2) If they are consistent, it is determined that the function is normal.

[0037] (3) If it is detected that the left / right electronic rearview mirror camera imaging is inconsistent with the rear camera imaging, but the right / left electronic rearview mirror camera imaging is consistent with the rear camera imaging, it is determined that the left / right electronic rearview mirror camera is faulty, the imaging of the rear camera is then overlaid after being deformed by cutting, to provide a temporary field of view for the driver, and the vehicle alarm system is used to alarm the driver to remind the driver to find a nearby repair point for repair in time.

[0038] (4) If they are all inconsistent, the rearview mirror camera imaging is processed and displayed on the vehicle central control screen, and the vehicle alarm system is used to alarm the driver to remind the driver to find a nearby repair point for repair in time.

[0039] ​If the electronic rearview mirror controller is provided with a watchdog module, the main control module and the image processing module are monitored by the watchdog module, and if a fault occurs, the controller is restarted by controlling the power module.

[0040] The fault analysis and processing body step further includes:

[0041] (5) The controller back-drawing actuator left and right electronic rearview mirror screen images are compared with the images collected by the rear camera through perception fusion technology;

[0042] (6) If the unilateral comparison result is inconsistent, the inconsistent side electronic rearview mirror screen display is cut off, the rear camera imaging is displayed on the vehicle central control screen after processing, the driver is alarmed through the vehicle alarm system, and the driver is reminded to find a nearby repair point for repair in time;

[0043] (7) If the bilateral comparison result is inconsistent, the rearview mirror camera imaging is displayed on the vehicle central control screen after processing, the driver is alarmed through the vehicle alarm system, and the driver is reminded to find a nearby repair point for repair in time.

[0044] The preferred embodiments of the present patent are described in detail above, but the present patent is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the present patent.

Claims

1. A control method of an electronic rearview mirror control system, the electronic rearview mirror control system comprising three parts: a sensor, a controller and an actuator; the sensor comprising a left electronic rearview mirror camera, a right electronic rearview mirror camera and a rear camera; the controller being provided with a function control module and an image processing module; the actuator being provided with a central control screen, a left electronic rearview mirror screen and a right electronic rearview mirror screen; the sensor transmitting the collected images to the controller, which outputs the images to the left electronic rearview mirror screen and the right electronic rearview mirror screen after image processing; the controller being further provided with a watchdog module, characterized in that: The control method comprises determining functional safety requirements and fault analysis processing, The determining of the functional safety requirements comprises: (1) confirming fault modes, including electronic rearview mirror imaging delay or sticking, electronic rearview mirror imaging reversal, left and right electronic rearview mirror imaging inversion, and electronic rearview mirror imaging incompleteness or loss; (2) determining safety targets and ASIL levels according to the HARA analysis of the controllability C, severity S and exposure E in combination with the main operation scene of the function according to the ISO 26262 functional safety standard requirement, and obtaining a safety target SG; (3) deriving the functional safety requirements FSR through fault tree analysis FTA according to the safety target SG obtained through the HARA analysis; The fault analysis processing steps are: (1) judging whether the camera imaging of the electronic rearview mirror control system is correct through mutual verification of the imaging of the rear camera and the left and right electronic rearview mirror cameras by using the perception fusion technology; (2) if they are consistent, it is judged that the function is normal; (3) if the left / right electronic rearview mirror camera imaging is inconsistent with the rear camera imaging, but the right / left electronic rearview mirror camera imaging is consistent with the rear camera imaging, it is judged that the left / right electronic rearview mirror camera is faulty, the imaging of the rear camera is overlaid on the erroneous imaging after being deformed by cutting, a temporary field of view is provided for the driver, and the vehicle alarm system is used to alarm the driver to remind the driver to find a nearby repair point for repair in time; (4) if they are all inconsistent, the imaging of the rearview mirror camera is displayed on the vehicle central control screen after being processed, and the vehicle alarm system is used to alarm the driver to remind the driver to find a nearby repair point for repair in time.

2. The control method according to claim 1, characterized by: The watchdog module is used to monitor the function control module and the image processing module, and if a fault occurs, the controller is restarted through the control power module.

3. The control method according to claim 2, characterized in that: The fault analysis processing steps further comprise: (5) the controller is used to collect the images of the left and right electronic rearview mirror screens, and the images collected by the rear camera are compared through the perception fusion technology; (6) if the unilateral comparison result is inconsistent, the inconsistent side electronic rearview mirror screen display is cut off, the imaging of the rear camera is displayed on the vehicle central control screen after being processed, and the vehicle alarm system is used to alarm the driver to remind the driver to find a nearby repair point for repair in time; (7) if the bilateral comparison result is inconsistent, the imaging of the rearview mirror camera is displayed on the vehicle central control screen after being processed, and the vehicle alarm system is used to alarm the driver to remind the driver to find a nearby repair point for repair in time.

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