A wiper motor fault diagnosis method, system and device, and a vehicle

Abstract

This invention provides a method, system, and device for diagnosing wiper motor faults, as well as a vehicle. The method includes: identifying and diagnosing wiper motor faults under various control states, ensuring the controller maintains wiper motor fault monitoring capabilities regardless of its operating state; adding current overload identification during stall identification to better ensure the wiper motor operates within a safe range and improve wiper performance; and combining wiper return switch status and wiper motor output current to determine stall status, improving the robustness and accuracy of stall identification and making the wiper function more reliable and closed-loop. Therefore, this invention, through wiper diagnosis and wiper control state transitions, performs different fault diagnoses under different state modes, solving the problem that current wiper motor stall fault identification is significantly affected by current fluctuations, failing to correctly identify stall and provide wiper motor protection.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, and in particular to a method, system and device for diagnosing windshield wiper motor faults, and a vehicle. Background Technology

[0002] There are four Automotive Safety Integration Levels (ASIL): ASILA, ASIL B, ASIL C, and ASIL D. ASILA represents the lowest safety integrity level, and ASIL D represents the highest. As a critical automotive component, windshield wipers must meet the functional safety level ASIL B. Even if the related controller module software fails, the wipers must remain actuated, a necessary function during limp driving (a driving mode where the vehicle experiences a malfunction). Therefore, correctly operating the wipers, real-time monitoring of their status, and fault diagnosis are crucial. Furthermore, the wiper module needs to execute different fault responses for different fault types.

[0003] Currently, most wiper fault diagnosis solutions cannot comprehensively identify wiper faults and lack an effective switching mechanism between wiper fault modes and control modes. This often leads to inaccurate diagnosis, resulting in wiper motor burnout, or misdiagnosis during wiper control, causing overprotection or functional failure, affecting the user's driving experience. Especially in the wiper stall detection process, existing wiper diagnostic solutions primarily rely on the wiper motor drive current feedback value for stall judgment. However, the current fluctuates during wiper operation, and the resulting surge current can easily cause misjudgment of stall, leading to the wiper function being shut down. Furthermore, existing wiper diagnostic solutions do not consider other electrical faults in the wiper drive during stall detection, such as overload and short-ground faults. Since stall detection generally takes a certain amount of time, if a short-ground fault occurs during stall detection, the drive output must be shut down immediately to prevent motor burnout. Simultaneously, overload fault diagnosis is also crucial during stall detection, as prolonged overload can cause wire burnout and safety malfunctions; therefore, overload faults also need to be recorded and addressed. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a method, system and device for diagnosing windshield wiper motor faults, and a vehicle, to solve the technical problems that occur in the current windshield wiper fault diagnosis.

[0005] To achieve the above and other related objectives, the present invention provides a method for diagnosing wiper motor faults, comprising the following steps:

[0006] When the controller receives a wiper activation command and the wiper motor voltage is within a preset voltage range, the controller enters the wiper activation state. The wiper motor is controlled by the controller to provide drive output to the wipers in the vehicle, so that the wipers can perform activation or deactivation based on the provided drive output. The drive output provided by the wiper motor in the wiper activation state is activation.

[0007] The controller performs a first drive output short-to-ground fault diagnosis and a first stall voltage comparison on the wiper motor when the wiper is in the on state. When the wiper motor does not have a first drive output short-to-ground fault and the first stall voltage of the wiper motor is greater than or equal to a preset stall voltage threshold, the controller enters the stall identification state.

[0008] The controller, in the stall detection state, performs second drive output short-to-ground fault diagnosis, current overload diagnosis, and second stall voltage comparison on the wiper motor, as well as wiper position identification, to diagnose whether the wiper motor has a stall fault. If the wiper motor has a current overload, the controller enters a default state, where the drive output provided by the wiper motor is off. If the wiper motor does not have a second drive output short-to-ground fault, and the second stall voltage of the wiper motor is greater than or equal to a preset stall voltage threshold, and the wiper's return position does not change within a preset time period, then the wiper motor is confirmed to have a stall fault.

[0009] In one embodiment of the present invention, after the controller in the stall identification state performs second drive output short-to-ground fault diagnosis, current overload diagnosis, and second stall voltage comparison on the wiper motor, and performs position identification on the wiper, the method further includes:

[0010] When the wiper motor experiences a short-to-ground fault in the second drive output, the controller returns to the wiper-on state; among which, when the controller in the stall identification state performs second drive output short-to-ground fault diagnosis, current overload diagnosis, and second stall voltage comparison on the wiper motor, the second drive output short-to-ground fault diagnosis has the highest priority.

[0011] Alternatively, the controller returns to the default state when the wiper's return position changes within a preset time period.

[0012] In one embodiment of the present invention, after the controller performs a first drive output short-to-ground fault diagnosis and a first stall voltage comparison on the wiper motor in the wiper-on state, the method further includes: when the wiper motor experiences a first drive output short-to-ground fault, the controller returns to the default state;

[0013] Among them, when the controller performs the first drive output short-ground fault diagnosis and the first stall voltage comparison on the wiper motor in the wiper-on state, the first drive output short-ground fault diagnosis has the highest priority.

[0014] In one embodiment of the present invention, before the controller enters the wiper-on state, the method further includes:

[0015] The wiper motor is diagnosed with open circuit fault and short power supply fault by the controller in the default state.

[0016] If the wiper motor has an open circuit fault in its drive output or a short power supply fault in its drive output, the controller will remain in its default state.

[0017] If the wiper motor does not have an open circuit fault in its drive output and does not have a short power supply fault in its drive output, the controller enters a drive detection state. In this state, the controller compares the voltage of the wiper motor with a preset voltage range and determines whether to enter a wiper-on state based on the voltage comparison result. In this drive detection state, the controller can respond to wiper drive requests.

[0018] In one embodiment of the present invention, the process of comparing the voltage of the wiper motor with a preset voltage range by a controller in a drive detection state, and determining whether the controller enters the wiper-on state based on the voltage comparison result, includes:

[0019] The voltage of the wiper motor in the drive detection state is detected and recorded as the target voltage;

[0020] By comparing the controller target voltage under the drive detection state with the preset voltage range, it is determined whether the target voltage is within the preset voltage range;

[0021] If the target voltage is within the preset voltage range, the controller will enter the wiper-on state when it receives a wiper-on command.

[0022] If the target voltage is not within the preset voltage range, the controller returns to the default state.

[0023] In one embodiment of the present invention, if the controller is in the wiper-on state or the controller is in the stall detection state, it enters the drive detection state after receiving the wiper-off command.

[0024] The present invention also provides a wiper motor fault diagnosis system, the system comprising:

[0025] A stall status identification module is used to diagnose a first drive output short-to-ground fault and compare a first stall voltage of the wiper motor when the wiper is in the on state. When the wiper motor does not have a first drive output short-to-ground fault and the first stall voltage of the wiper motor is greater than or equal to a preset stall voltage threshold, the controller enters the stall identification state. When the controller receives a wiper activation command and the voltage of the wiper motor is within a preset voltage range, the controller enters the wiper activation state. The wiper motor is controlled by the controller to provide drive output to the wipers in the vehicle, so that the wipers perform on or off actions based on the provided drive output. The drive output provided by the wiper motor in the wiper activation state is "on".

[0026] The stall fault diagnosis module is used to diagnose whether the wiper motor has a stall fault by performing second drive output short-to-ground fault diagnosis, current overload diagnosis, and second stall voltage comparison on the wiper motor through the controller in the stall identification state, as well as to identify the position of the wiper. If the wiper motor has a current overload, the controller enters a default state, wherein the drive output provided by the wiper motor in the default state is turned off. If the wiper motor does not have a second drive output short-to-ground fault, and the second stall voltage of the wiper motor is greater than or equal to a preset stall voltage threshold, and the wiper's return position does not change within a preset time period, then the wiper motor is confirmed to have a stall fault.

[0027] In one embodiment of the present invention, the system further includes:

[0028] The default state fault diagnosis module is used to diagnose drive output open circuit faults and drive output short power supply faults of the wiper motor through the controller in the default state. If the wiper motor has a drive output open circuit fault or a drive output short power supply fault, the controller maintains the default state. If the wiper motor does not have a drive output open circuit fault or a drive output short power supply fault, the controller enters the drive detection state. In the drive detection state, the controller can respond to wiper drive requests.

[0029] The voltage fault diagnosis module is used to detect the voltage of the wiper motor in the drive detection state and record it as the target voltage; and to determine whether the target voltage is within the preset voltage range by comparing the controller target voltage in the drive detection state with the preset voltage range; if the target voltage is within the preset voltage range, the controller enters the wiper-on state when it receives the wiper-on command; if the target voltage is not within the preset voltage range, the controller returns to the default state.

[0030] The present invention also provides a wiper motor diagnostic device, the device comprising: a wiper motor and a controller; the wiper motor is controlled by the controller to provide drive output to the wipers in the vehicle, so that the wipers perform opening or closing actions based on the provided drive output;

[0031] The wiper motor and the controller are used in the wiper motor fault diagnosis method as described in any one of the above.

[0032] The present invention also provides a vehicle that includes a wiper motor diagnostic device as described above.

[0033] As described above, this invention provides a wiper motor fault diagnosis method, system, and device, as well as a vehicle, with the following beneficial effects: By performing fault diagnosis and identification of the wiper motor under various control states, this invention ensures that the controller has wiper motor fault monitoring capabilities regardless of its operating state. Simultaneously, by adding current overload identification during the stall identification process, this invention can better ensure that the wiper motor operates within a safe range, improving wiper performance. Furthermore, this invention can combine the wiper return switch status and the wiper motor output current to determine the wiper motor stall state, improving the robustness and accuracy of stall identification and making the wiper function more closed-loop and reliable. Therefore, this invention, through wiper diagnosis and wiper control state switching, performs different fault diagnoses under different state modes, effectively solving the problem that current wiper motor fault identification is greatly affected by current fluctuations, failing to correctly identify stall and protect the wiper motor. Attached Figure Description

[0034] Figure 1 This is a flowchart illustrating a wiper motor fault diagnosis method provided in one embodiment of the present invention;

[0035] Figure 2 This is a flowchart illustrating a wiper motor fault diagnosis method provided in another embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of the hardware structure of a wiper motor fault diagnosis system provided in an embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of a fault diagnosis process for a controller provided in one embodiment of the present invention. Detailed Implementation

[0038] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0039] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0040] Current wiper motor diagnostic solutions often involve directly shutting off the output after confirming the fault condition, lacking fault jump and retry mechanisms. This leads to missed and false diagnoses, and fails to create a closed-loop interaction between control and diagnosis. Furthermore, for the crucial stall fault identification in wiper diagnostics, existing solutions primarily rely on judging stall based on the wiper motor's output current. This method is highly susceptible to current fluctuations and cannot accurately identify stalls and implement wiper motor protection.

[0041] Therefore, based on the aforementioned defects, Figure 1 A schematic flowchart of a wiper motor fault diagnosis method is shown. Specifically, in an exemplary embodiment, as follows: Figure 1 As shown, this embodiment provides a method for diagnosing wiper motor faults, including the following steps:

[0042] S110, when the controller receives a wiper activation command and the wiper motor voltage is within a preset voltage range, the controller enters the wiper activation state; wherein, the wiper motor is controlled by the controller to provide drive output to the wipers in the vehicle, so that the wipers perform activation or deactivation actions based on the provided drive output, and the drive output provided by the wiper motor in the wiper activation state is activation. As an example, the preset voltage range in this embodiment can be set according to actual conditions, so this embodiment does not impose a specific numerical limitation.

[0043] S120, the controller performs a first drive output short-to-ground fault diagnosis and a first stall voltage comparison on the wiper motor while the wipers are in the on state. When the wiper motor does not have a first drive output short-to-ground fault, and the first stall voltage of the wiper motor is greater than or equal to a preset stall voltage threshold, the controller enters the stall identification state. As an example, the preset stall voltage threshold in this embodiment can be set according to actual conditions, so this embodiment does not limit the specific value.

[0044] S130, the controller in the stall detection state performs second drive output short-to-ground fault diagnosis, current overload diagnosis, and second stall voltage comparison on the wiper motor, and identifies the position of the wiper to diagnose whether the wiper motor has a stall fault. If the wiper motor has a current overload, the controller enters a default state; wherein, the drive output provided by the wiper motor in the default state is off. If the wiper motor does not have a second drive output short-to-ground fault, and the second stall voltage of the wiper motor is greater than or equal to a preset stall voltage threshold, and the wiper's return position does not change within a preset time period, then it is confirmed that the wiper motor has a stall fault. As an example, the preset time period in this embodiment can be set according to actual conditions, for example, 10 seconds can be used as the preset time period. As an example, when identifying the position of the wiper in this embodiment, the wiper return switch position can be used as the standard to identify whether the wiper is always in the return switch position or not in the return switch position within the preset time period. As another example, in this embodiment, the wiper position can also be identified by installing a wiper position sensor.

[0045] Therefore, this embodiment, by performing fault diagnosis and identification of the wiper motor under various control states, ensures that the controller has the ability to monitor wiper motor faults regardless of its operating state. Furthermore, by adding current overload identification during the stall identification process, this embodiment can better ensure that the wiper motor operates within a safe range, improving wiper performance. Moreover, this embodiment can combine the wiper return switch status and the wiper motor output current to determine the wiper motor stall status, improving the robustness and accuracy of stall identification and making the wiper function more closed-loop and reliable. Therefore, this embodiment, through wiper diagnosis and wiper control state switching, performs different fault diagnoses under different state modes, effectively solving the problem that current wiper motor fault identification is greatly affected by current fluctuations, failing to correctly identify stall and provide wiper motor protection.

[0046] According to the above description, in an exemplary embodiment, after step S120 performs a first drive output short-ground fault diagnosis and a first stall voltage comparison on the wiper motor through the controller in the wiper-on state, the method further includes: when the wiper motor experiences a first drive output short-ground fault, the controller returns to a default state; wherein, when the wiper motor performs a first drive output short-ground fault diagnosis and a first stall voltage comparison on the wiper motor through the controller in the wiper-on state, the first drive output short-ground fault diagnosis has the highest priority.

[0047] According to the above description, in an exemplary embodiment, after step S130 performs second drive output short-ground fault diagnosis, current overload diagnosis, and second stall voltage comparison on the wiper motor through the controller in stall identification state, and performs position identification on the wiper, it may further include: when the wiper motor experiences a second drive output short-ground fault, the controller returns to the wiper-on state; wherein, when the controller in stall identification state performs second drive output short-ground fault diagnosis, current overload diagnosis, and second stall voltage comparison on the wiper motor, the second drive output short-ground fault diagnosis has the highest priority. Alternatively, when the wiper's return position changes within a preset time period, the controller returns to the default state. Therefore, in this embodiment, during the stall detection process, the wiper motor output current and the wiper return switch position are combined to diagnose stall faults. When the wiper motor output current reaches the stall threshold, the wiper current is periodically checked to see if it has reached the stall threshold. At the same time, the wiper return switch position is collected. If the wiper return switch position does not change within a certain period of time, it is considered that the wiper has stalled, and the wiper drive output is turned off to protect the wiper motor from damage.

[0048] According to the above description, in an exemplary embodiment, before the controller enters the wiper activation state, this embodiment may further include: performing drive output open circuit fault diagnosis and drive output short power supply fault diagnosis on the wiper motor through the controller in the default state; if the wiper motor has a drive output open circuit fault or a drive output short power supply fault, the controller maintains the default state; if the wiper motor does not have a drive output open circuit fault and the wiper motor does not have a drive output short power supply fault, the controller enters the drive detection state, and compares the voltage of the wiper motor with a preset voltage range through the controller in the drive detection state, and determines whether the controller enters the wiper activation state based on the voltage comparison result; wherein, the controller can respond to wiper drive requests in the drive detection state. Specifically, in this embodiment, the process of comparing the voltage of the wiper motor with a preset voltage range by the controller in the drive detection state, and determining whether the controller enters the wiper-on state based on the voltage comparison result, includes: detecting the voltage of the wiper motor in the drive detection state, denoted as the target voltage; determining whether the target voltage is within the preset voltage range by comparing the controller's target voltage in the drive detection state with the preset voltage range; if the target voltage is within the preset voltage range, the controller enters the wiper-on state when it receives a wiper-on command; if the target voltage is not within the preset voltage range, the controller returns to the default state. As an example, the preset voltage range in this embodiment can be set according to actual conditions, so this embodiment does not impose a specific numerical limitation.

[0049] According to the above description, in any of the above exemplary embodiments, if the controller is in the wiper-on state or the controller is in the stall detection state, it enters the drive detection state after receiving the wiper-off command.

[0050] In another exemplary embodiment of the present invention, such as Figure 2 As shown, this embodiment provides a method for diagnosing wiper motor faults, including the following steps:

[0051] The controller is initialized and powered on, entering State 0. In State 0, the wiper motor drive output is off. In State 0, the controller performs OL (Open Load) and SCB (Short Circuit to Battery) fault diagnosis on the wiper motor. If the diagnosis result is no fault, meaning the wiper motor has neither an OL nor an SCB fault, the controller jumps to State 1. If the wiper motor has either an OL or an SCB fault, the controller remains in State 0. In this embodiment or other embodiments, an SCB fault can also be referred to as a drive output short power supply fault, an OL fault as a drive output open circuit fault, and State 0 as the default state. Similarly, in other embodiments, a drive output short power supply fault can also be referred to as an SCB fault, a drive output open circuit fault as an OL fault, and the default state as State 0.

[0052] Upon entering State 1, the controller is now capable of responding to wiper drive requests. Simultaneously, the controller will determine the output voltage of the wiper motor. Specifically, it will diagnose whether the wiper motor's drive output voltage is within the normal voltage range. If the wiper motor's drive output voltage is within the normal range, the controller will jump to State 2 and activate the wiper output upon receiving a valid wiper activation command. If the wiper motor's drive output voltage is outside the normal voltage range, the controller will jump back from State 1 to State 0. In this embodiment, the normal voltage range can be preset according to actual conditions; no specific numerical limit is specified here. In this embodiment or other embodiments, State 1 can also be referred to as the drive detection state, and State 2 can also be referred to as the wiper activation state. Similarly, in other embodiments, the drive detection state can also be referred to as State 1, and the wiper activation state can also be referred to as State 2. Figure 2 In this context, "normal voltage" refers to the normal voltage, "normal voltage range" refers to the normal voltage range, and "normal state" refers to the state when the wiper motor's drive output voltage is within the normal voltage range, i.e., State 1.

[0053] Upon entering State 2, the controller performs SCG (Short Circuit to Ground) fault diagnosis and stall voltage comparison on the wiper motor. If an SCG fault occurs in the wiper motor, the controller will directly jump back to State 0. If no SCG fault occurs, but the stall voltage is greater than or equal to the stall voltage threshold, the controller will jump from State 2 to State 3 and then perform stall identification on the wiper motor. If an SCG fault occurs in State 2, the controller will directly jump back to State 0; if no SCG fault occurs in State 2 and the stall voltage is less than the stall voltage threshold, the controller will remain in State 2. As an example, the stall voltage threshold in this embodiment can be set according to actual conditions, so no specific numerical limit is specified here. In this embodiment or other embodiments, the SCG fault in State 2 can also be referred to as the first drive output short-to-ground fault, the stall voltage comparison in State 2 can also be referred to as the first stall voltage comparison, and State 3 can also be referred to as the stall identification state. Similarly, the first drive output short-to-ground fault in other embodiments can also be referred to as the SCG fault in State 2, the first stall voltage comparison can also be referred to as the stall voltage comparison in State 2, and the stall identification state can also be referred to as State 3. After entering State 2, when performing SCG fault diagnosis and stall voltage comparison on the wiper motor, the SCG fault diagnosis has the highest priority.

[0054] Upon entering State 3, the controller performs overload diagnosis, SCG fault diagnosis, and stall voltage comparison on the wiper motor based on the drive current information, and identifies the wiper position. If an SCG fault occurs in the wiper motor in State 3, the controller jumps back to State 2 to re-confirm the SCG fault. If an SCG fault also occurs in State 2, the controller jumps from State 2 to State 0 and attempts to resume drive operation. If no SCG fault occurs in State 3, and the stall voltage of the wiper motor in State 3 is greater than or equal to a preset stall voltage threshold, and the wiper's return position remains unchanged within a preset time period, a stall fault is confirmed in the wiper motor. The controller then exits drive control and terminates output. The controller is then re-initialized and powered on. Figure 2 In this system, the wiper module is mainly composed of a controller.

[0055] Upon entering State 3, when performing SCG fault diagnosis, current overload diagnosis, and stall voltage comparison on the wiper motor, SCG fault diagnosis has the highest priority. As an example, the preset stall voltage threshold in this embodiment can be set according to actual conditions, so no specific numerical limit is specified here. As an example, the preset time period in this embodiment can be set according to actual conditions; for example, 10 seconds can be used as the preset time period. In this embodiment or other embodiments, the SCG fault in State 2 can also be referred to as the first drive output short-to-ground fault, and State 3 can also be referred to as the stall identification state. Similarly, the first drive output short-to-ground fault in other embodiments can also be referred to as the SCG fault in State 2, and the stall identification state can also be referred to as State 3. In this embodiment or other embodiments, the SCG fault in State 3 can also be referred to as the second drive output short-to-ground fault, and the stall voltage comparison in State 3 can also be referred to as the second stall voltage comparison. Similarly, the second drive output short-to-ground fault in other embodiments can also be referred to as the SCG fault in State 3, and the second stall voltage comparison can also be referred to as the stall voltage comparison in State 3. As an example, in this embodiment, when identifying the position of the windshield wiper, the position of the wiper return switch can be used as a standard to identify whether the wiper remains in the return switch position or does not remain in the return switch position within a preset time period. As another example, in this embodiment, the wiper position can also be identified by installing a wiper position sensor.

[0056] Therefore, given that wiper motor stall detection takes a certain amount of time, it's possible that the drive current might not reach the stall threshold during the detection process, failing to achieve stall protection. However, heat accumulation could lead to motor damage. This embodiment provides a solution that effectively coordinates fault protection and drive control switching by adding overload diagnosis during stall detection. If an overload occurs, a retry will be triggered to attempt recovery. Furthermore, in fault diagnosis, the SCG fault diagnosis level is the highest, exceeding stall fault diagnosis and current overload fault diagnosis. Therefore, in State 2, output protection is achieved by prioritizing SCG fault detection. On the other hand, most current wiper stall detection solutions rely solely on wiper drive current threshold judgment, which is prone to misdiagnosis and lacks robustness. Therefore, in this embodiment, during the stall detection process, the wiper motor output current and the wiper return switch position are combined to diagnose stall faults. When the wiper motor output current reaches the stall threshold, the wiper current is periodically checked to see if it reaches the stall threshold. At the same time, the wiper return switch position is collected. If the wiper return switch position does not change within a certain period of time, it is considered that the wiper has stalled, and the wiper drive output is turned off to protect the wiper motor from damage.

[0057] In summary, this invention provides a method for diagnosing wiper motor faults. When the controller receives a wiper activation command and the wiper motor voltage is within a preset voltage range, the controller enters a wiper activation state. The wiper motor is controlled by the controller to provide drive output to the wipers in the vehicle, enabling the wipers to perform activation or deactivation actions based on the provided drive output. The drive output provided by the wiper motor in the wiper activation state is "on". The controller in the wiper activation state performs a first drive output short-to-ground fault diagnosis and a first stall voltage comparison on the wiper motor. When the wiper motor does not exhibit a first drive output short-to-ground fault, and the first stall voltage of the wiper motor is greater than or equal to a preset stall voltage... When the threshold is reached, the controller enters a stall detection state. In this state, the controller performs second drive output short-to-ground fault diagnosis, current overload diagnosis, and second stall voltage comparison on the wiper motor, as well as position identification on the wiper, to diagnose whether the wiper motor has a stall fault. If the wiper motor experiences a current overload, the controller enters a default state, where the drive output provided by the wiper motor is off. If the wiper motor does not experience a second drive output short-to-ground fault, and the second stall voltage of the wiper motor is greater than or equal to a preset stall voltage threshold, and the wiper's return position does not change within a preset time period, then a stall fault in the wiper motor is confirmed. Therefore, this method, by performing fault diagnosis and identification of the wiper motor under various control states, ensures that the controller has the ability to monitor wiper motor faults regardless of its operating state. Furthermore, by adding current overload identification during the stall identification process, this method can better ensure that the wiper motor operates within a safe range, improving wiper performance. Moreover, this method can combine the wiper return switch status and the wiper motor output current to determine the wiper motor stall status, improving the robustness and accuracy of stall identification and making the wiper function more closed-loop and reliable. Thus, this method, through wiper diagnosis and wiper control state transitions, performs different fault diagnoses under different state modes, effectively solving the problem that current wiper motor diagnostics are greatly affected by current fluctuations, failing to correctly identify stall and provide wiper motor protection.

[0058] In another exemplary embodiment of the present invention, such as Figure 3 As shown, this embodiment provides a wiper motor fault diagnosis system, including:

[0059] The default state fault diagnosis module 310 is used to diagnose drive output open circuit faults and drive output short power supply faults of the wiper motor through the controller in the default state. If the wiper motor has a drive output open circuit fault or a drive output short power supply fault, the controller maintains the default state. If the wiper motor does not have a drive output open circuit fault or a drive output short power supply fault, the controller enters the drive detection state. In the drive detection state, the controller can respond to wiper drive requests. In the default state, the drive output provided by the wiper motor is off.

[0060] The voltage fault diagnosis module 320 is used to detect the voltage of the wiper motor in the drive detection state and record it as the target voltage; and to determine whether the target voltage is within the preset voltage range by comparing the controller target voltage in the drive detection state with a preset voltage range; if the target voltage is within the preset voltage range, the controller enters the wiper-on state when it receives a wiper-on command; if the target voltage is not within the preset voltage range, the controller returns to the default state; as an example, the preset voltage range in this embodiment can be set according to the actual situation, so this embodiment does not limit the specific value.

[0061] The stall state identification module 330 is used to perform a first drive output short-to-ground fault diagnosis and a first stall voltage comparison on the wiper motor via a controller in the wiper-on state. When the wiper motor does not have a first drive output short-to-ground fault, and the first stall voltage of the wiper motor is greater than or equal to a preset stall voltage threshold, the controller enters the stall identification state. When the controller receives a wiper-on command and the voltage of the wiper motor is within a preset voltage range, the controller enters the wiper-on state. The wiper motor is controlled by the controller to provide drive output to the wipers in the vehicle, enabling the wipers to perform on / off actions based on the provided drive output. The drive output provided by the wiper motor in the wiper-on state is "on". As an example, the preset voltage range in this embodiment can be set according to actual conditions, so no specific numerical limit is specified here. Similarly, the preset stall voltage threshold in this embodiment can be set according to actual conditions, so no specific numerical limit is specified here. Furthermore, when the wiper motor experiences a first drive output short-to-ground fault, the controller returns to the default state; among which, when the wiper motor is diagnosed for a first drive output short-to-ground fault and compared with a first stall voltage by the controller in the wiper-on state, the first drive output short-to-ground fault diagnosis has the highest priority.

[0062] The stall fault diagnosis module 340 is used to diagnose whether the wiper motor has a stall fault by performing second drive output short-to-ground fault diagnosis, current overload diagnosis, and second stall voltage comparison on the wiper motor through the controller in the stall identification state, as well as to identify the position of the wiper. If the wiper motor has a current overload, the controller enters a default state, wherein the drive output provided by the wiper motor in the default state is off. If the wiper motor does not have a second drive output short-to-ground fault, and the second stall voltage of the wiper motor is greater than or equal to a preset stall voltage threshold, and the wiper's return position does not change within a preset time period, then the wiper motor is confirmed to have a stall fault. As an example, the preset time period in this embodiment can be set according to actual conditions, for example, 10 seconds can be used as the preset time period. As an example, when identifying the position of the wiper, this embodiment can use the wiper return switch position as the standard to identify whether the wiper is always in the return switch position or not in the return switch position within the preset time period. As another example, this embodiment can also identify the wiper position by installing a wiper position sensor. When the wiper motor experiences a short-to-ground fault in its second drive output, the controller returns to the wiper-on state. Specifically, when the controller in stall detection state performs second drive output short-to-ground fault diagnosis, current overload diagnosis, and second stall voltage comparison on the wiper motor, the second drive output short-to-ground fault diagnosis has the highest priority. Alternatively, when the wiper's return position changes within a preset time period, the controller returns to the default state. Therefore, in the stall detection process, this embodiment can combine the wiper motor output current and the wiper return switch position for stall fault diagnosis. When the wiper motor output current reaches the stall threshold, it continues to periodically diagnose whether the wiper current has reached the stall threshold, while simultaneously collecting the wiper return switch position. If the wiper return switch position does not change within a certain time, it is considered that the wiper is stalled, and the wiper drive output is shut off to protect the wiper motor from damage.

[0063] In this embodiment, if the controller is in the wiper-on state or the controller is in the stall detection state, it will enter the drive detection state after receiving the wiper-off command.

[0064] In summary, this invention provides a wiper motor fault diagnosis system. By performing fault diagnosis and identification on the wiper motor under various control states, it ensures that the controller has the ability to monitor wiper motor faults regardless of its operating state. Furthermore, the system incorporates current overload identification during stall detection, further ensuring the wiper motor operates within a safe range and improving wiper performance. Moreover, the system can combine the wiper return switch status and wiper motor output current to determine the wiper motor stall status, improving the robustness and accuracy of stall detection and making the wiper function more closed-loop and reliable. Therefore, this system, through wiper diagnosis and wiper control state transitions, performs different fault diagnoses under different state modes, effectively solving the problem that current wiper motor fault identification is greatly affected by current fluctuations, failing to correctly identify stall and provide wiper motor protection.

[0065] It should be noted that the wiper motor fault diagnosis system provided in the above embodiments and the wiper motor fault diagnosis method provided in the above embodiments belong to the same concept. The specific operation methods of each module in the wiper motor fault diagnosis system have been described in detail in the above method embodiments, and will not be repeated here. In practical applications, the wiper motor fault diagnosis system provided in the above embodiments can be assigned to different functional modules as needed, that is, the internal structure of the system can be divided into different functional modules to complete all or part of the functions described in the above method embodiments, and this is not a limitation here.

[0066] In another exemplary embodiment of the present invention, this embodiment provides a wiper motor diagnostic device, including: a wiper motor and a controller; the wiper motor is controlled by the controller to provide drive output to the wipers in a vehicle, so that the wipers perform on or off actions based on the provided drive output; wherein, the wiper motor and the controller are applied to the wiper motor fault diagnosis method as described in any of the above embodiments. The fault diagnosis process of the controller in this embodiment is as follows: Figure 4 shown. Specifically,

[0067] After the controller completes initialization and power-on, it enters State 0. In State 0, the wiper motor drive output is off. In State 0, the controller performs OL (On-Line) and SCB (Side Circuit) fault diagnosis on the wiper motor. If the diagnosis result is no fault, meaning the wiper motor has neither an OL nor an SCB fault, the controller jumps to State 1. If the wiper motor has either an OL or an SCB fault, the controller remains in State 0. In this embodiment or other embodiments, an SCB fault can also be referred to as a drive output short-circuit fault, an OL fault as a drive output open-circuit fault, and State 0 as the default state. Similarly, in other embodiments, a drive output short-circuit fault can also be referred to as an SCB fault, an drive output open-circuit fault as an OL fault, and the default state as State 0.

[0068] Upon entering State 1, the controller is now capable of responding to wiper drive requests. Simultaneously, the controller will determine the output voltage of the wiper motor. Specifically, it will diagnose whether the wiper motor's drive output voltage is within the normal voltage range. If the wiper motor's drive output voltage is within the normal range, the controller will jump to State 2 and activate the wiper output upon receiving a valid wiper activation command. If the wiper motor's drive output voltage is outside the normal voltage range, the controller will jump back from State 1 to State 0. In this embodiment, the normal voltage range can be preset according to actual conditions; no specific numerical limit is specified here. In this embodiment or other embodiments, State 1 can also be referred to as the drive detection state, and State 2 can also be referred to as the wiper activation state. Similarly, in other embodiments, the drive detection state can also be referred to as State 1, and the wiper activation state can also be referred to as State 2. Figure 4 In this context, the "normal" state indicates the state when the drive output voltage of the wiper motor is within the normal voltage range, i.e., State 1.

[0069] Upon entering State 2, the controller performs SCG (Short Circuit to Ground) fault diagnosis and stall voltage comparison on the wiper motor. If an SCG fault occurs in the wiper motor, the controller will directly jump back to State 0. If no SCG fault occurs, but the stall voltage is greater than or equal to the stall voltage threshold, the controller will jump from State 2 to State 3 and then perform stall identification on the wiper motor. If an SCG fault occurs in State 2, the controller will directly jump back to State 0; if no SCG fault occurs in State 2 and the stall voltage is less than the stall voltage threshold, the controller will remain in State 2. As an example, the stall voltage threshold in this embodiment can be set according to actual conditions, so no specific numerical limit is specified here. In this embodiment or other embodiments, the SCG fault in State 2 can also be referred to as the first drive output short-to-ground fault, the stall voltage comparison in State 2 can also be referred to as the first stall voltage comparison, and State 3 can also be referred to as the stall identification state. Similarly, the first drive output short-to-ground fault in other embodiments can also be referred to as the SCG fault in State 2, the first stall voltage comparison can also be referred to as the stall voltage comparison in State 2, and the stall identification state can also be referred to as State 3. After entering State 2, when performing SCG fault diagnosis and stall voltage comparison on the wiper motor, the SCG fault diagnosis has the highest priority.

[0070] Upon entering State 3, the controller performs overload diagnosis, SCG fault diagnosis, and stall voltage comparison on the wiper motor based on the drive current information, and identifies the wiper position. If an SCG fault occurs in the wiper motor in State 3, the controller jumps back to State 2 to re-confirm the SCG fault. If an SCG fault also occurs in State 2, the controller jumps from State 2 to State 0 and attempts to resume drive operation. If no SCG fault occurs in State 3, and the stall voltage of the wiper motor in State 3 is greater than or equal to a preset stall voltage threshold, and the wiper's return position remains unchanged within a preset time period, a stall fault is confirmed, the controller exits drive control, and terminates output. When entering State 3, SCG fault diagnosis has the highest priority when performing SCG fault diagnosis, overload diagnosis, and stall voltage comparison on the wiper motor. As an example, the preset stall voltage threshold in this embodiment can be set according to actual conditions, so no specific numerical limit is specified here. As an example, the preset time period in this embodiment can be set according to actual conditions, for example, 10 seconds can be used as the preset time period. In this embodiment or other embodiments, the SCG fault in State2 can also be called the first drive output short ground fault, and State3 can also be called the stall identification state. Similarly, the first drive output short ground fault in other embodiments can also be called the SCG fault in State2, and the stall identification state can also be called State3. In this embodiment or other embodiments, the SCG fault in State3 can also be called the second drive output short ground fault, and the stall voltage comparison in State3 can also be called the second stall voltage comparison. Similarly, the second drive output short ground fault in other embodiments can also be called the SCG fault in State3, and the second stall voltage comparison can also be called the stall voltage comparison in State3. As an example, when identifying the position of the wiper in this embodiment, the wiper return switch position can be used as the standard to identify whether the wiper is always in the return switch position or not in the return switch position within a preset time period. As another example, in this embodiment, the wiper position can also be identified by installing a wiper position sensor.

[0071] Therefore, given that wiper motor stall detection takes a certain amount of time, it's possible that the drive current might not reach the stall threshold during the detection process, failing to achieve stall protection. However, heat accumulation could lead to motor damage. This embodiment provides a solution that effectively coordinates fault protection and drive control switching by adding overload diagnosis during stall detection. If an overload occurs, a retry will be triggered to attempt recovery. Furthermore, in fault diagnosis, the SCG fault diagnosis level is the highest, exceeding stall fault diagnosis and current overload fault diagnosis. Therefore, in State 2, output protection is achieved by prioritizing SCG fault detection. On the other hand, most current wiper stall detection solutions rely solely on wiper drive current threshold judgment, which is prone to misdiagnosis and lacks robustness. Therefore, in this embodiment, during the stall detection process, the wiper motor output current and the wiper return switch position are combined to diagnose stall faults. When the wiper motor output current reaches the stall threshold, the wiper current is periodically checked to see if it reaches the stall threshold. At the same time, the wiper return switch position is collected. If the wiper return switch position does not change within a certain period of time, it is considered that the wiper has stalled, and the wiper drive output is turned off to protect the wiper motor from damage.

[0072] In summary, this invention provides a wiper motor fault diagnosis device. By performing fault diagnosis and identification on the wiper motor under various control states, it ensures that the controller has the ability to monitor wiper motor faults regardless of its operating state. Furthermore, by adding current overload identification during the stall identification process, this device can better ensure that the wiper motor operates within a safe range, improving wiper performance. Moreover, this device can combine the wiper return switch status and the wiper motor output current to determine the wiper motor stall state, improving the robustness and accuracy of stall identification and making the wiper function more closed-loop and reliable. Therefore, this device, through wiper diagnosis and wiper control state switching, performs different fault diagnoses in different state modes, effectively solving the problem that current wiper motor fault identification is greatly affected by current fluctuations, failing to correctly identify stall and provide wiper motor protection.

[0073] It should be noted that the wiper motor fault diagnosis device provided in the above embodiments and the wiper motor fault diagnosis method provided in the above embodiments belong to the same concept. The specific operation of the wiper motor fault diagnosis method has been described in detail in the above embodiments and will not be repeated here. In practical applications, the wiper motor fault diagnosis device provided in the above embodiments can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described in the above method embodiments. This is not a limitation here.

[0074] In another exemplary embodiment of the present invention, this embodiment provides a vehicle including a wiper motor diagnostic device as described in the above embodiments. It should be noted that the vehicle provided in this embodiment and the wiper motor fault diagnostic device provided in the above embodiments belong to the same concept. Therefore, the specific technical processes and effects of the vehicle in this embodiment are the same as those described in the wiper motor diagnostic device in the above embodiments, and will not be repeated here. As an example, the vehicle in this embodiment can be a fuel-powered vehicle or a new energy vehicle, etc.

[0075] It should be understood that although the terms first, second, third, etc., may be used in the embodiments of the present invention to describe drive output short-ground faults, these drive output short-ground faults should not be limited to these terms. These terms are only used to distinguish drive output short-ground faults from each other. For example, without departing from the scope of the embodiments of the present invention, a first drive output short-ground fault may also be referred to as a second drive output short-ground fault, and similarly, a second drive output short-ground fault may also be referred to as a first drive output short-ground fault.

[0076] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for diagnosing wiper motor faults, characterized in that, The method includes the following steps: When the controller receives a wiper activation command and the wiper motor voltage is within a preset voltage range, the controller enters the wiper activation state. The wiper motor is controlled by the controller to provide drive output to the wipers in the vehicle, so that the wipers can perform activation or deactivation based on the provided drive output. The drive output provided by the wiper motor in the wiper activation state is activation. The controller performs a first drive output short-to-ground fault diagnosis and a first stall voltage comparison on the wiper motor when the wiper is in the on state. When the wiper motor does not have a first drive output short-to-ground fault and the first stall voltage of the wiper motor is greater than or equal to a preset stall voltage threshold, the controller enters the stall identification state. The controller, in the stall detection state, performs second drive output short-to-ground fault diagnosis, current overload diagnosis, and second stall voltage comparison on the wiper motor, as well as wiper position identification, to diagnose whether the wiper motor has a stall fault. If the wiper motor has a current overload, the controller enters a default state, in which the drive output provided by the wiper motor is turned off. If the wiper motor does not have a second drive output short-to-ground fault, and the second stall voltage of the wiper motor is greater than or equal to a preset stall voltage threshold, and the wiper's return position does not change within a preset time period, then the wiper motor is confirmed to have a stall fault. After the controller in the stall detection state performs second drive output short-to-ground fault diagnosis, current overload diagnosis, and second stall voltage comparison on the wiper motor, and identifies the position of the wiper, the method further includes: When the wiper motor experiences a short-to-ground fault in the second drive output, the controller returns to the wiper-on state; among which, when the controller in the stall identification state performs second drive output short-to-ground fault diagnosis, current overload diagnosis, and second stall voltage comparison on the wiper motor, the second drive output short-to-ground fault diagnosis has the highest priority. Alternatively, the controller returns to the default state when the wiper's return position changes within a preset time period.

2. The wiper motor fault diagnosis method according to claim 1, characterized in that, After the controller performs a first drive output short-to-ground fault diagnosis and a first stall voltage comparison on the wiper motor in the wiper-on state, the method further includes: when the wiper motor experiences a first drive output short-to-ground fault, the controller returns to the default state; Among them, when the controller performs the first drive output short-ground fault diagnosis and the first stall voltage comparison on the wiper motor in the wiper-on state, the first drive output short-ground fault diagnosis has the highest priority.

3. The wiper motor fault diagnosis method according to claim 1 or 2, characterized in that, Before the controller enters the wiper-on state, the method further includes: The wiper motor is diagnosed with open circuit fault and short power supply fault by the controller in the default state. If the wiper motor has an open circuit fault in its drive output or a short power supply fault in its drive output, the controller will remain in its default state. If the wiper motor does not have an open circuit fault in its drive output and does not have a short power supply fault in its drive output, the controller enters a drive detection state. In this state, the controller compares the voltage of the wiper motor with a preset voltage range and determines whether to enter a wiper-on state based on the voltage comparison result. In this drive detection state, the controller can respond to wiper drive requests.

4. The wiper motor fault diagnosis method according to claim 3, characterized in that, The process of comparing the voltage of the wiper motor with a preset voltage range by the controller in the drive detection state, and determining whether the controller enters the wiper on state based on the voltage comparison result, includes: The voltage of the wiper motor in the drive detection state is detected and recorded as the target voltage; By comparing the controller target voltage under the drive detection state with the preset voltage range, it is determined whether the target voltage is within the preset voltage range; If the target voltage is within the preset voltage range, the controller will enter the wiper-on state when it receives a wiper-on command. If the target voltage is not within the preset voltage range, the controller returns to the default state.

5. The wiper motor fault diagnosis method according to claim 4, characterized in that, If the controller is in the wiper-on state or in the stall detection state, it will enter the drive detection state after receiving the wiper-off command.

6. A wiper motor fault diagnosis system, characterized in that, The system includes: The stall status identification module is used to perform first drive output short-ground fault diagnosis and first stall voltage comparison of the wiper motor through the controller when the wiper is on. When the wiper motor does not experience a first drive output short-to-ground fault, and the first stall voltage of the wiper motor is greater than or equal to a preset stall voltage threshold, the controller enters the stall identification state. When the controller receives a wiper activation command and the voltage of the wiper motor is within a preset voltage range, the controller enters the wiper activation state; wherein, the wiper motor is controlled by the controller to provide drive output to the wipers in the vehicle, so that the wipers perform activation or deactivation actions based on the provided drive output, and the drive output provided by the wiper motor in the wiper activation state is activation; The stall fault diagnosis module is used to diagnose whether the wiper motor has a stall fault by performing second drive output short-to-ground fault diagnosis, current overload diagnosis, and second stall voltage comparison on the wiper motor through the controller in the stall identification state, as well as by identifying the position of the wiper. If the wiper motor has a current overload, the controller enters a default state, wherein the drive output provided by the wiper motor in the default state is off. If the wiper motor does not have a second drive output short-to-ground fault, and the second stall voltage of the wiper motor is greater than or equal to a preset stall voltage threshold, and the wiper's return position does not change within a preset time period, then the wiper motor is confirmed to have a stall fault. When the wiper motor has a second drive output short-to-ground fault, the controller returns to the wiper on state. Among the second drive output short-to-ground fault diagnosis, current overload diagnosis, and second stall voltage comparison performed by the controller in the stall identification state, the second drive output short-to-ground fault diagnosis has the highest priority. Alternatively, when the wiper's return position changes within a preset time period, the controller returns to the default state.

7. The wiper motor fault diagnosis system according to claim 6, characterized in that, The system also includes: The default state fault diagnosis module is used to diagnose drive output open circuit faults and drive output short power supply faults of the wiper motor through the controller in the default state; if the wiper motor has a drive output open circuit fault or a drive output short power supply fault, the controller remains in the default state. If the wiper motor does not have an open circuit fault in its drive output and the wiper motor does not have a short power supply fault in its drive output, then the controller enters the drive detection state; wherein, the controller is able to respond to wiper drive requests in the drive detection state. The voltage fault diagnosis module is used to detect the voltage of the wiper motor in the drive detection state and record it as the target voltage; and to determine whether the target voltage is within the preset voltage range by comparing the controller target voltage in the drive detection state with the preset voltage range; if the target voltage is within the preset voltage range, the controller enters the wiper-on state when it receives the wiper-on command; if the target voltage is not within the preset voltage range, the controller returns to the default state.

8. A wiper motor diagnostic device, characterized in that, The device includes a wiper motor and a controller; the wiper motor is controlled by the controller to provide drive output to the wipers in the vehicle, so that the wipers perform opening or closing actions based on the provided drive output; The wiper motor and the controller are used in the wiper motor fault diagnosis method as described in any one of claims 1 to 5.

9. A vehicle, characterized in that, The vehicle includes the wiper motor diagnostic device as described in claim 8.

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