A method and device for diagnosing low-voltage faults during vehicle startup

Abstract

This application discloses a method and device for diagnosing low-voltage faults during vehicle startup. The method includes: in response to receiving engine ignition status information from an engine management system, sending a first ignition status setting message to the bottom layer of an automatic transmission control unit, thereby disabling the low-voltage fault diagnosis function of the bottom layer of the automatic transmission control unit; wherein the first ignition status setting message is 1; and if engine startup success information is received from the engine management system, in response to receiving a startup success flag from the engine management system, sending an ignition clearing message to the bottom layer of the automatic transmission control unit, thereby restoring the low-voltage fault diagnosis function of the bottom layer of the automatic transmission control unit. This application improves the robustness of vehicle fault diagnosis functions.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and more specifically, to a method and device for diagnosing low-voltage faults during vehicle startup. Background Art

[0002] During the vehicle starting process, the battery drives the starter to rotate. At the moment the starter starts, the armature does not rotate, resulting in a large starting current, causing the battery voltage to drop. This process is inevitable.

[0003] National standards stipulate that the entire vehicle's electrical appliances can operate normally between 9-16V, and modern automotive electrical appliances can basically do this; however, battery aging or low operating environment temperature will affect the battery's performance, which may cause the battery voltage to be lower than 9V or even lower than 6V during the startup process.

[0004] In the prior art, the automatic transmission control unit (TCU) has the function of detecting the power supply voltage. The TCU compares the detected voltage value of the vehicle's KL30 with a threshold value. If it is lower than the threshold value and remains lower than the threshold value for a period of time, it is determined that a low-voltage fault has occurred, the fault is recorded, and a signal is sent to light the fault warning light on the instrument panel and perform relevant fault handling measures. However, the startup process of the vehicle itself has the phenomenon of voltage being pulled down. If the low-voltage fault alarm is triggered during the startup process, the post-processing measures for the low-voltage fault after the vehicle starts normally will usually cut off the function of the actuator, resulting in a functional failure of the vehicle. Therefore, the low-voltage fault diagnosis function of the TCU is applicable to the vehicle after it is powered on or the startup is stable.

[0005] In the prior art, the TCU receives engine status information from the Engine Management System (EMS) via the CAN bus. If the TCU detects the engine is in the crank state, the TCU's power supply diagnostics are disabled. The TCU's power supply diagnostics are re-enabled when the TCU detects a change in engine status.

[0006] Currently, an increasing number of TCUs utilize suppliers to develop both hardware and underlying software, while OEMs independently develop the application layer. This often involves incorporating proprietary diagnostic strategies for low power supply voltage. This can result in the TCU application layer disabling power supply diagnostics when the engine is cranked, while also reporting other faults such as low power supply voltage for the solenoid valve or 5V sensor. This can cause functional failures throughout the vehicle, leading to unnecessary complications.

[0007] Therefore, the existing technical solution simply judges the low-voltage fault based on the engine status without considering the diagnostic matching between the bottom layer and application layer of the TCU, resulting in unnecessary vehicle functional failures during the vehicle startup process, making the robustness of the vehicle fault diagnosis function low. Summary of the Invention

[0008] The present application provides a method and device for diagnosing low-voltage faults during vehicle startup. The application layer of the TCU interacts with the bottom layer of the TCU according to the engine status during vehicle startup, ensuring that misdiagnosis of low-voltage faults does not occur during startup, thereby improving the robustness of the vehicle's fault diagnosis function.

[0009] This application provides a method for diagnosing low-voltage faults during vehicle startup, including:

[0010] In response to receiving information from the engine management system indicating that the engine is in an ignition state, first ignition state setting information is sent to a bottom layer of the automatic transmission control unit, so that the bottom layer of the automatic transmission control unit shields a low voltage fault diagnosis function; wherein the first ignition state setting information is 1;

[0011] If the engine start success information is received from the engine management system, the ignition clear information is sent to the bottom layer of the automatic transmission control unit in response to receiving the start success flag of the engine management system, so that the bottom layer of the automatic transmission control unit restores the low voltage fault diagnosis function.

[0012] Preferably, if the engine start success information from the engine management system is not received and the CAN communication always exists, an ignition clear position information is sent to the bottom layer of the automatic transmission control unit in response to receiving the engine start failure information from the engine management system.

[0013] Preferably, if the engine start success information from the engine management system is not received and the CAN communication is interrupted, it is determined whether the main chip of the automatic transmission control unit is powered off;

[0014] If the main chip of the automatic transmission control unit is not powered off, when the time difference between the current moment and the moment when the engine is received in the ignition state is greater than the threshold, the ignition clear position information is sent to the bottom layer of the automatic transmission control unit.

[0015] Preferably, if the main chip of the automatic transmission control unit is powered off and the automatic transmission control unit completes initialization, the second ignition state setting information is sent to the bottom layer of the automatic transmission control unit, and the second ignition state setting information is 0.

[0016] Preferably, after sending the second ignition state setting information, if it is again received that the engine is in the ignition state, the first ignition state setting information is again sent to the bottom layer of the automatic transmission control unit.

[0017] The present application also provides a low-voltage fault diagnosis device during vehicle startup, comprising an information receiving module and an information sending module;

[0018] The information receiving module is used to receive information from the engine management system indicating that the engine is in the ignition state; the information sending module is used to send first ignition state setting information to the bottom layer of the automatic transmission control unit in response to receiving the information from the engine management system indicating that the engine is in the ignition state, so that the bottom layer of the automatic transmission control unit shields the low voltage fault diagnosis function; wherein the first ignition state setting information is 1;

[0019] The information receiving module is also used to receive the engine start success information and start success flag from the engine management system; the information sending module is also used to send ignition clear information to the bottom layer of the automatic transmission control unit in response to receiving the start success flag, so that the bottom layer of the automatic transmission control unit restores the low voltage fault diagnosis function.

[0020] Preferably, it also includes a judgment module;

[0021] The judgment module is used to determine whether CAN communication has always existed;

[0022] If CAN communication exists all the time, the information receiving module is also used to receive the engine start failure information from the engine management system; the information sending module is also used to send ignition clear information to the bottom layer of the automatic transmission control unit in response to receiving the engine start failure information from the engine management system.

[0023] Preferably, the judgment module is further used to judge whether the main chip of the automatic transmission control unit is powered off;

[0024] The low-voltage fault diagnosis device further includes a timing module, the timing module being used to accumulate a time difference between the current moment and the moment when the engine is received to be in the ignition state;

[0025] The information sending module is further used to send ignition clear position information to the bottom layer of the automatic transmission control unit when the main chip of the automatic transmission control unit is not powered off and the time difference is greater than a threshold.

[0026] Preferably, the judgment module is further used to judge whether the automatic transmission control unit has completed initialization;

[0027] The information sending module is further configured to send second ignition state setting information to the bottom layer of the automatic transmission control unit in response to the automatic transmission control unit completing initialization, where the second ignition state setting information is 0.

[0028] Preferably, the information receiving module is further configured to receive again that the engine is in the ignition state after sending the second ignition state setting information;

[0029] The information sending module is further configured to send the first ignition state setting information to the bottom layer of the automatic transmission control unit again in response to receiving again that the engine is in the ignition state.

[0030] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0032] Figure 1 A flow chart of the low-voltage fault diagnosis method during vehicle startup provided in this application;

[0033] Figure 2 The low-voltage fault diagnosis timing diagram provided by this application when the engine starts successfully;

[0034] Figure 3 This is a structural diagram of the low-voltage fault diagnosis device during vehicle startup provided in this application. DETAILED DESCRIPTION

[0035] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0036] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0037] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0038] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0039] This application provides a method and device for diagnosing low-voltage faults during vehicle startup. During the vehicle startup process, the TCU application layer interacts with the TCU bottom layer based on the engine status, taking into account both engine status determination and matching power supply diagnosis between the TCU bottom layer and the application layer. This method shields low-voltage fault diagnosis only during vehicle startup, improving the robustness of the vehicle fault diagnosis function. Furthermore, in the event of an unsuccessful engine startup, the different consequences of the unsuccessful startup are categorized, and clearing and recovery processing is performed based on the different vehicle startup results.

[0040] It should be noted that the basic software layer (BSW) of the TCU consists of the following four parts:

[0041] Microcontroller Abstraction Layer (MCAL): is the driver software directly related to the hardware, such as operations on memory, communication registers, IO ports, etc.

[0042] ECU Abstraction Layer (ECUAL): unifies the basic functions and interfaces of the controller, such as parsing CAN message content, forwarding gateway messages, controlling memory read and write processes, etc.

[0043] Services Layer: Provides various background services for the application layer, such as network management, memory management, bus communication management services, and operating systems.

[0044] Complex Device Drivers (CDD): Provides users with the possibility to write their own special device driver software.

[0045] Application Software Layer (ASW) of TCU: It is the software that implements specific application functions and can contain multiple software components.

[0046] The low voltage fault diagnosis method provided by this application during vehicle startup is applied to the application layer of the TCU. Figure 1 As shown, the low voltage fault diagnosis method includes:

[0047] S110: In response to receiving the engine ignition status information from the engine management system (EMS), first ignition status setting information is sent to the bottom layer of the automatic transmission control unit (TCU), so that the bottom layer of the TCU blocks the low voltage fault diagnosis function. The first ignition status setting information is 1.

[0048] Specifically, the ASW of the TCU receives the ignition status information of the EMS through the vehicle CAN communication. The engine is in the ignition state corresponding to the CRANK mode. The ASW of the TCU receives the information that the engine is in the ignition state (such as Figure 2 After time 1 in the figure, the ignition status setting information is marked as 1, forming the first ignition status setting information. The TCU's ASW then forwards this first ignition status setting information to the TCU's BSW via an interface call. After receiving this first ignition status setting information forwarded by the ASW via the interface, the TCU's BSW disables the low-voltage fault diagnosis function, including KL30-related fault diagnosis and fault measures.

[0049] After EMS sends the information that the engine is in ignition state, the engine starts to start (such as Figure 2 At moment 2), the voltage of the power supply (battery) is pulled down. During the vehicle startup process, the voltage of the power supply gradually recovers. If the vehicle starts normally, after the vehicle startup is completed, the battery voltage returns to normal (such as Figure 2 At time 3), the EMS sends a start success flag to the ASW of the TCU, indicating that the engine start is successful.

[0050] S120: Receive the EMS status sent by the EMS via the vehicle CAN communication, and determine whether the engine start is successful based on the EMS status; if so, execute S130; otherwise, execute S140.

[0051] S130: In response to receiving the startup success flag of the EMS, the ignition clear information (such as Figure 2 At moment 4), the BSW of the TCU resumes the low-voltage fault diagnosis function.

[0052] After receiving information indicating that the engine is in the ignition state, the TCU's automatic switch (ASW) continuously sends the first ignition state set message to the TCU's back-switch (BSW). Receiving the startup success flag from the EMS triggers the ASW to send an ignition clear message to the BSW. Once the BSW receives the ignition clear message from the ASW, the low-voltage fault diagnosis function is restored.

[0053] Even if the engine starts successfully, if the ASW does not receive the start success flag, the ASW will not send the ignition clear position information to the BSW, and the BSW will continue to block the low voltage fault diagnosis function.

[0054] S140: Determine whether CAN communication is still in effect. If so, execute S150; otherwise, execute S160.

[0055] S150 : Sending ignition clear information to the BSW of the TCU in response to receiving the engine start failure information from the EMS.

[0056] After receiving information indicating that the engine is in the ignition state, the TCU's automatic switch (ASW) continuously sends the first ignition state set message to the TCU's back-switch (BSW). If CAN communication is active, the engine status signal sent by the EMS to the ASW via CAN communication changes from the ignition state to the unsuccessful start state if the engine fails to start. Receiving the unsuccessful engine start message from the EMS triggers the ASW to send the ignition clear message to the TCU's back-switch (BSW).

[0057] If ASW does not receive the engine start failure information, it will not send the ignition clear position information to BSW, and BSW will continue to block the low voltage fault diagnosis function.

[0058] S160: If CAN communication is interrupted during the startup process, determine whether the TCU main chip is powered off. If not, execute S170; if so, execute S190.

[0059] S170: Determine whether the time difference between the current time and the time when the engine is in the ignition state is received is greater than a threshold. If so, execute S180; otherwise, continue to execute S170.

[0060] S180: Send ignition clear information to the BSW of the TCU.

[0061] After receiving information that the engine is in the ignition state, the ASW continuously sends the first ignition state set information to the BSW. If CAN communication is interrupted during the startup process, the EMS cannot interact with the ASW. If the TCU main chip is not powered off, its timing module accumulates the time difference from the moment the engine is in the ignition state to the current moment. When the time difference is greater than a threshold (for example, the threshold is the maximum time the EMS can pull the starter), the BSW no longer needs to disable the low-voltage fault diagnosis function. Therefore, the ASW sends the ignition clear information to the BSW, allowing the BSW to restore the low-voltage fault diagnosis function.

[0062] S190: Determine whether the TCU has completed initialization. If so, execute S1100; otherwise, continue to execute S190.

[0063] If the main chip of the TCU loses power, it needs to be reinitialized. Only after the initialization is completed can the next round of control be carried out.

[0064] S1100: Send second ignition state setting information to the BSW of the TCU, where the second ignition state setting information is 0. Then execute S1110.

[0065] After the TCU main chip is initialized, the ignition status setting information sent by ASW to BSW changes from 1 to 0 again, so that BSW does not execute the low-voltage fault diagnosis strategy for vehicle startup.

[0066] S1110: If the engine is in the ignition state, the first ignition state setting information is sent to the BSW of the TCU again to start a new round of vehicle starting process.

[0067] Based on the above-mentioned low-voltage fault diagnosis method, the present application also provides a low-voltage fault diagnosis device during vehicle startup. Figure 3 As shown, the low-voltage fault diagnosis device includes an information receiving module 310 and an information sending module 320 .

[0068] The information receiving module 310 is used to receive the engine in ignition state information from the EMS; the information sending module 320 is used to send the first ignition state setting information to the BSW of the TCU in response to receiving the engine in ignition state information from the EMS, so that the BSW of the TCU shields the low voltage fault diagnosis function; wherein the first ignition state setting information is 1.

[0069] The information receiving module 310 is also used to receive the engine start success information and the start success flag from the EMS; the information sending module 320 is also used to send ignition clear information to the BSW of the TCU in response to receiving the start success flag, so that the BSW of the TCU restores the low voltage fault diagnosis function.

[0070] As an embodiment, the low-voltage fault diagnostic device further includes a determination module 330. Determination module 330 is configured to determine whether CAN communication is always present. If CAN communication is always present, information receiving module 310 is further configured to receive an engine start failure message from the EMS. Information sending module 320 is further configured to transmit an ignition clear message to the BSW of the TCU in response to receiving the engine start failure message from the EMS.

[0071] As an embodiment, the determination module 330 is further configured to determine whether the TCU main chip is powered off. The low-voltage fault diagnostic device also includes a timing module 340, which is configured to accumulate the time difference between the current moment and the moment when the engine ignition status is received. The information transmission module 320 is further configured to transmit an ignition clear position message to the TCU's backswitching switch (BSW) if the TCU main chip is powered on and the time difference is greater than a threshold.

[0072] As an embodiment, the judgment module 330 is further configured to judge whether the TCU has completed initialization; the information sending module 320 is further configured to send second ignition state setting information to the BSW of the TCU in response to the TCU completing initialization, where the second ignition state setting information is 0.

[0073] As an embodiment, the information receiving module 310 is further used to receive the engine being in the ignition state again after sending the second ignition state setting information; the information sending module 320 is further used to send the first ignition state setting information to the BSW of the TCU again in response to receiving the engine being in the ignition state again.

[0074] Although some specific embodiments of the present application have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A method for diagnosing low voltage faults during vehicle startup, characterized in that: include: In response to receiving information from the engine management system indicating that the engine is in an ignition state, first ignition state setting information is sent to a bottom layer of an automatic transmission control unit, so that the bottom layer of the automatic transmission control unit shields a low voltage fault diagnosis function; wherein the first ignition state setting information is 1; If an engine start success message is received from the engine management system, an ignition clear message is sent to the bottom layer of the automatic transmission control unit in response to receiving the start success flag of the engine management system, so that the bottom layer of the automatic transmission control unit resumes the low voltage fault diagnosis function; If the engine start success message from the engine management system is not received and the CAN communication is interrupted, it is determined whether the main chip of the automatic transmission control unit is powered off; If the main chip of the automatic transmission control unit is not powered off, when the time difference between the current moment and the moment when the engine is received in the ignition state is greater than a threshold, ignition clear information is sent to the bottom layer of the automatic transmission control unit.

2. The low voltage fault diagnosis method during vehicle startup according to claim 1, characterized in that: If the engine start success information from the engine management system is not received and the CAN communication still exists, an ignition clear position information is sent to the bottom layer of the automatic transmission control unit in response to receiving the engine start failure information from the engine management system.

3. The low voltage fault diagnosis method during vehicle startup according to claim 2, characterized in that: If the main chip of the automatic transmission control unit is powered off and the automatic transmission control unit completes initialization, second ignition state setting information is sent to the bottom layer of the automatic transmission control unit, and the second ignition state setting information is 0.

4. The low voltage fault diagnosis method during vehicle startup according to claim 3, characterized in that: After sending the second ignition state setting information, if it is received again that the engine is in the ignition state, the first ignition state setting information is sent again to the bottom layer of the automatic transmission control unit.

5. A low voltage fault diagnosis device during vehicle startup, characterized in that: It includes an information receiving module and an information sending module; The information receiving module is used to receive information from the engine management system indicating that the engine is in the ignition state; the information sending module is used to send first ignition state setting information to the bottom layer of the automatic transmission control unit in response to receiving the information from the engine management system indicating that the engine is in the ignition state, so that the bottom layer of the automatic transmission control unit shields the low voltage fault diagnosis function; wherein the first ignition state setting information is 1; The information receiving module is further configured to receive engine start success information and a start success flag from the engine management system; the information sending module is further configured to send ignition clear information to the bottom layer of the automatic transmission control unit in response to receiving the start success flag, so that the bottom layer of the automatic transmission control unit restores the low voltage fault diagnosis function; The judgment module is also used to judge whether the main chip of the automatic transmission control unit is powered off; The low-voltage fault diagnosis device further includes a timing module, the timing module being configured to accumulate a time difference between the current moment and the moment when the engine is received to be in the ignition state; The information sending module is further configured to send ignition clear information to the bottom layer of the automatic transmission control unit when the main chip of the automatic transmission control unit is not powered off and the time difference is greater than a threshold.

6. The low voltage fault diagnosis device during vehicle startup according to claim 5, characterized in that: Also includes a judgment module; The judgment module is used to judge whether CAN communication has always existed; If CAN communication always exists, the information receiving module is also used to receive the engine start failure information from the engine management system; the information sending module is also used to send ignition clear information to the bottom layer of the automatic transmission control unit in response to receiving the engine start failure information from the engine management system.

7. The low voltage fault diagnosis device during vehicle startup according to claim 6, characterized in that: The judgment module is further used to judge whether the automatic transmission control unit has completed initialization; The information sending module is further configured to send second ignition state setting information to a bottom layer of the automatic transmission control unit in response to the automatic transmission control unit completing initialization, where the second ignition state setting information is 0.

8. The low voltage fault diagnosis device during vehicle startup according to claim 7, characterized in that: The information receiving module is further configured to receive again that the engine is in the ignition state after sending the second ignition state setting information; The information sending module is further configured to send the first ignition state setting information to the bottom layer of the automatic transmission control unit again in response to receiving again that the engine is in the ignition state.

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