Stall control method and device of electronic water pump and electronic control unit

Abstract

The invention discloses a stall control method and device of an electronic water pump and an electronic control unit, and belongs to the field of automobile engine cooling systems. The invention provides an automatic and targeted control strategy which can quickly and effectively enable the electronic water pump to recover normal operation. Specifically, after it is determined that the electronic water pump stalls, firstly, under the condition that an engine operates normally, the electronic pump is controlled to stop running, faults are tried to be eliminated, and fault counting is conducted; then, whether the engine needs to be shut down or not is judged according to the current temperature of the engine and the accumulated fault frequency; and if the engine needs to be stopped, the engine is controlled to be stopped, and faults are reported synchronously. After the engine is stopped for a period of time, the engine is tried to be restarted to verify whether the fault is recovered after the engine is stopped. Due to the fact that fault elimination and fault report can be conducted in time after the electronic water pump is confirmed to stall, the engine cannot be seriously affected, and the safety of the whole vehicle is guaranteed.

Description

Technical Field

[0001] This application relates to the field of automotive engine cooling systems, and in particular to a stall control method, device, and electronic control unit for an electronic water pump. Background Technology

[0002] In the field of automotive engine cooling systems, electronic water pumps are now widely used due to their advantages such as precise control of coolant flow and rapid response.

[0003] However, under actual operating conditions, electric water pumps are susceptible to stalling due to various factors. For example, the presence of air bubbles in the cooling system can cause the pump impeller to spin idly, preventing the formation of an effective coolant delivery circuit. Alternatively, in low-temperature environments, the viscosity of the coolant increases significantly, leading to a sharp increase in the load on the pump motor and triggering stalling. Furthermore, malfunctions in the pump motor itself, such as short circuits in the motor windings or wear on the bearings, can also cause abnormal operation of the electric water pump, resulting in stalling.

[0004] Electric water pump stalling directly affects engine cooling. For example, it can lead to overheating, causing a series of problems such as decreased engine performance and component damage. In severe cases, it can even cause the head gasket to blow, seriously threatening driving safety. Therefore, how to quickly and effectively restore the electric water pump to normal operation when it stalls has become a pressing problem to be solved in this field. Summary of the Invention

[0005] This application provides a stall control method, device, and electronic control unit for an electronic water pump. The technical solution is as follows: On the one hand, a stall control method for an electronic water pump is provided, the method comprising: The actual operating current of the electronic water pump is obtained, and the current operating state of the electronic water pump is determined based on the actual operating current and a current threshold; wherein, the current threshold is the current value required for the electronic water pump to operate normally. If the electronic water pump is currently in a stall state, while the engine is running normally, a first speed value is sent to the electronic water pump to control the electronic water pump to stop operating; the first speed value is the target speed when the electronic water pump experiences a speed failure. After the electronic water pump stops operating for a first period of time, a second speed value is sent to the electronic water pump, and a fault count is performed; the second speed value is the target speed when the electronic water pump is operating normally. If, based on the engine's current coolant temperature and the cumulative number of faults, it is determined that the engine shutdown conditions have been met, a shutdown command is sent to the engine, and a fault report is submitted. After the engine has been idle for a second period of time, the accumulated number of faults is reset to zero, and a start command is sent to the engine to restart it.

[0006] In one possible implementation, determining the current operating state of the electronic water pump based on the actual operating current and the current threshold includes: Obtain the actual operating voltage and actual rotational speed of the electronic water pump; The current threshold is determined based on the actual operating voltage and the actual rotational speed; If the actual operating current is greater than the current threshold, and the abnormal current condition lasts for at least a preset duration, it is determined that the electronic water pump is currently in the stall state.

[0007] In another possible implementation, the method further includes: If the current water temperature of the engine is less than or equal to a preset water temperature threshold, and the cumulative number of faults is greater than or equal to a first threshold, it is determined that the engine shutdown condition has been met.

[0008] In another possible implementation, the method further includes: If the current water temperature of the engine is greater than a preset water temperature threshold, and the cumulative number of faults is greater than or equal to a second threshold, it is determined that the engine shutdown condition has been met; wherein, the second threshold is less than the first threshold.

[0009] In another possible implementation, the fault reporting includes: The component-level fault signal indicating abnormal speed of the electronic water pump is output through the RS trigger; Specifically, after the RS trigger outputs the component-level fault signal, the fault switch signal is activated. The activated fault switch signal is sent to the fault management module of the engine management system to instruct the fault management module to upgrade the speed fault of the electronic water pump to the target level engine system-level fault according to the fault level determination rules.

[0010] In another possible implementation, the method further includes: After the engine restarts, if the electronic water pump has returned to normal operation, control the electronic water pump to operate according to the second speed value.

[0011] In another possible implementation, the method further includes: If the electronic water pump has not yet returned to normal operation, the fault clearance operation of sending the first speed value to the electronic water pump, sending the second speed value to the electronic water pump, and sending a shutdown command to the engine and restarting the engine when the engine shutdown condition has been met is executed again. If the electronic water pump fails to return to normal operation after multiple consecutive fault eliminations, the electronic water pump will automatically report a stall fault; the electronic water pump will report to the vehicle controller or engine management system.

[0012] On the other hand, a stall control device for an electronic water pump is provided, the device comprising: The acquisition module is configured to acquire the actual operating current of the electronic water pump; The determination module is configured to determine the current operating state of the electronic water pump based on the actual operating current and the current threshold; the current threshold is the current value required for the electronic water pump to operate normally. The control module is configured to send a first speed value to the electronic water pump when the engine is running normally, if the electronic water pump is currently in a stall state, in order to control the electronic water pump to stop operating; the first speed value is the target speed when the electronic water pump experiences a speed failure. The control module is also configured to send a second rotational speed value to the electronic water pump and perform fault counting after the electronic water pump stops operating for a first period of time; the second rotational speed value is the target rotational speed when the electronic water pump is operating normally. The control module is also configured to send a shutdown command to the engine and report the fault if it is determined that the engine shutdown conditions have been met based on the engine's current water temperature and the cumulative number of faults. The control module is also configured to reset the accumulated number of faults to zero and send a start command to the engine to restart the engine after the engine has been idle for a second period of time.

[0013] In one possible implementation, the determining module is configured as follows: Obtain the actual operating voltage and actual rotational speed of the electronic water pump; The current threshold is determined based on the actual operating voltage and the actual rotational speed; If the actual operating current is greater than the current threshold, and the abnormal current condition lasts for at least a preset duration, it is determined that the electronic water pump is currently in the stall state.

[0014] In another possible implementation, the control module is further configured as follows: If the current water temperature of the engine is less than or equal to a preset water temperature threshold, and the cumulative number of faults is greater than or equal to a first threshold, it is determined that the engine shutdown condition has been met.

[0015] In another possible implementation, the control module is further configured as follows: If the current water temperature of the engine is greater than a preset water temperature threshold, and the cumulative number of faults is greater than or equal to a second threshold, it is determined that the engine shutdown condition has been met; wherein, the second threshold is less than the first threshold.

[0016] In another possible implementation, the control module is further configured as follows: The component-level fault signal indicating abnormal speed of the electronic water pump is output through the RS trigger; Specifically, after the RS trigger outputs the component-level fault signal, the fault switch signal is activated. The activated fault switch signal is sent to the fault management module of the engine management system to instruct the fault management module to upgrade the speed fault of the electronic water pump to the target level engine system-level fault according to the fault level determination rules.

[0017] In another possible implementation, the control module is further configured as follows: After the engine restarts, if the electronic water pump has returned to normal operation, control the electronic water pump to operate according to the second speed value.

[0018] In another possible implementation, the control module is further configured as follows: If the electronic water pump has not yet returned to normal operation, the fault clearance operation of sending the first speed value to the electronic water pump, sending the second speed value to the electronic water pump, and sending a shutdown command to the engine and restarting the engine when the engine shutdown condition has been met is executed again. If the electronic water pump fails to return to normal operation after multiple consecutive fault eliminations, the electronic water pump will automatically report a stall fault; the electronic water pump will report to the vehicle controller or engine management system.

[0019] On the other hand, an electronic control unit is provided, the device including a microprocessor and a memory, the memory storing at least one piece of program code, the at least one piece of program code being loaded and executed by the microprocessor to implement the above-described stall control method for an electronic water pump.

[0020] On the other hand, a computer-readable storage medium is provided, wherein at least one piece of program code is stored therein, the at least one piece of program code being loaded and executed by a microprocessor to implement the above-described stall control method for an electronic water pump.

[0021] On the other hand, a computer program product is provided, which includes computer program code stored in a computer-readable storage medium. The microprocessor of the electronic control unit reads the computer program code from the computer-readable storage medium and executes the computer program code, causing the electronic control unit to perform the above-described stall control method for the electronic water pump.

[0022] The stall control scheme for an electronic water pump provided in this application proposes an automatic and targeted control strategy that can quickly and effectively restore the electronic water pump from a stall state to normal operation. Specifically, when a stall phenomenon is determined based on the actual operating current of the electronic water pump and the current during normal operation, the scheme first attempts to eliminate the fault by controlling the electronic pump to stop operating while the engine is running normally, and counts the faults. Next, the scheme determines whether the engine needs to be shut down based on the current engine temperature and the accumulated number of faults. If the engine needs to be shut down, it will be shut down and a fault report will be submitted simultaneously. Furthermore, after the engine has been shut down for a period of time, the scheme will attempt to restart the engine to verify whether the speed fault of the electronic water pump has been resolved after shutdown. Because this scheme promptly eliminates the fault and reports it after confirming a stall phenomenon, it avoids the risk of the engine being in a state of poor heat dissipation for a long time, which not only extends the engine's service life and improves its operational reliability but also ensures the safety of the entire vehicle. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a flowchart of a stall control method for an electronic water pump provided in an embodiment of this application; Figure 2 This is a schematic diagram of the stall control device for an electronic water pump provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of an electronic control unit provided in an embodiment of this application. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0026] In this application, the terms "first," "second," etc., are used to distinguish identical or similar items that have essentially the same function. It should be understood that there is no logical or temporal dependency between "first," "second," and "nth," nor does it limit the quantity or execution order. It should also be understood that although the following description uses the terms "first," "second," etc., to describe various elements, these elements should not be limited by the terms.

[0027] These terms are simply used to distinguish one element from another. For example, without departing from the various examples, the first element can be referred to as the second element, and similarly, the second element can be referred to as the first element. Both the first and second elements can be elements, and in some cases, they can be separate and distinct elements.

[0028] "At least one" refers to one or more elements. For example, at least one element can be one element, two elements, three elements, or any integer number of elements greater than or equal to one. "Multiple" refers to two or more elements. For example, multiple elements can be two elements, three elements, or any integer number of elements greater than or equal to two.

[0029] In this article, "and / or" indicates that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0030] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, data stored, data displayed, etc.) and signals involved in this application are all authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant regions.

[0031] Besides being susceptible to stalling due to the factors described in the background section, electronic water pumps may also malfunction during engine cold starts due to specific hardware failures. Specifically, immediately after engine start, wear on the water pump motor's carbon brushes or a malfunctioning Hall sensor may cause the actual operating current of the electronic water pump to be significantly higher than the current required for normal operation. Because the electronic water pump cannot respond properly to the target speed and runs at a fixed speed for an extended period, it will severely affect the normal operation of the engine, leading to phenomena such as overheating of the vehicle's coolant and coolant spraying from the expansion tank's pressure relief port.

[0032] Therefore, in order to solve a series of problems that may be caused by the stall of an electronic water pump, this application provides a stall control scheme for an electronic water pump. This scheme can quickly and effectively restore the electronic water pump from the stall state to the normal operating state after the electronic water pump stalls.

[0033] The stall control scheme for the electronic water pump provided in this application embodiment is executed by the engine ECU (Electronic Control Unit).

[0034] The engine ECU is a hardware carrier, specifically referring to the electronic control module installed in the vehicle to run the control strategy of the EMS (Engine Management System). EMS and engine ECU are essentially the same system's functional definition and its corresponding hardware carrier; that is, EMS is a general term at the functional level, specifically referring to a complete system composed of hardware, software, and calibration parameters, used to coordinate engine control and fault protection under all operating conditions.

[0035] It should be noted that the control logic and calibration parameters of the EMS are pre-written into the engine ECU's memory. The ECU's MCU (Microcontroller Unit) then performs the calculations, and the sensor signals are acquired and actuator commands are output through the input / output interface. The relationship between the two can be simply described as follows: without the hardware support of the ECU, the EMS control strategy cannot be implemented; conversely, without the EMS software logic, the ECU cannot perform any engine control functions.

[0036] The control logic of the stall control scheme for the electronic water pump provided in the embodiments of this application is described below.

[0037] The control logic includes a physical quantity acquisition and conversion process to convert signals such as the current, voltage, and actual speed of the electric water pump into numerical values ​​that can participate in logical operations. In addition, it includes the calculation process of the current threshold WaPmp_CurThrd. The current threshold WaPmp_CurThrd is determined by the converted actual speed and voltage of the electric water pump.

[0038] In addition, the control logic also includes the determination of abnormal speed of the electronic water pump. The scheme determines whether the electronic water pump is abnormally rotating by comparing the actual operating current of the electronic water pump (also known as the water pump feedback current) with the current threshold. If the actual operating current WaPmp_Current > the current threshold WaPmp_CurThrd, the water pump speed fault flag WaPmp_bSpdErr_U8 is set from 0 to 1. In addition, in order to avoid misjudgment caused by short-term fluctuations in current, the delay module will start timing the instant when the current abnormality condition changes from not being met (0) to being met (1). If the current abnormality time lasts for a preset duration (e.g., 500ms), that is, the delay module will continue timing until 500ms before determining that the water pump is stalled (WaPmp_bSpdErr_U8=1).

[0039] In addition, the control logic also includes, while the engine is running normally, attempting to eliminate the fault by requesting the water pump to start and stop, and counting the faults; and determining whether to request an engine shutdown based on the current engine temperature and the accumulated number of faults (also known as the fault cycle count). Furthermore, it requests an engine shutdown by sending an engine shutdown command, while simultaneously reporting an engine system-level fault.

[0040] Figure 1 This is a flowchart illustrating a stall control method for an electronic water pump according to an embodiment of this application. The method is executed by the engine ECU. See also... Figure 1 The method includes the following steps.

[0041] 101. The engine ECU obtains the actual operating current of the electronic water pump and determines the current operating status of the electronic water pump based on the actual operating current and current threshold.

[0042] In this embodiment, the engine ECU acquires not only the actual operating current of the electric water pump, but also its actual operating voltage and actual speed. That is, the engine ECU receives various sensor signals from the electric water pump, including water pump current (WaPmp_Current), water pump voltage (WaPmp_Voltage), and actual water pump speed (WaPmp_Actual_speed). These raw signals are first converted from analog to digital signals by the signal conversion module within the engine ECU before being sent to the logic unit for logical operations.

[0043] As an example, this application embodiment confirms water pump stall based on the water pump feedback current being much greater than the current during normal operation. That is, the aforementioned current threshold refers to the current value required for the electronic water pump to operate normally.

[0044] Accordingly, determining the current operating state of the electronic water pump based on its actual operating current and current threshold means: determining the current threshold based on the actual operating voltage and actual speed of the electronic water pump; if the actual operating current of the electronic water pump is greater than the current threshold, and the abnormal current condition lasts for at least a preset time, it is determined that the electronic water pump is currently in a stall state (also known as a speed fault state).

[0045] For example, the preset duration is 500ms, but this application does not limit it.

[0046] As another example, the current threshold can be determined by MAP mapping based on the actual operating voltage and actual speed of the electric water pump. For example, the MAP table of the current threshold is a two-dimensional calibration matrix. The horizontal axis of the matrix is ​​the actual speed of the electric water pump, and the vertical axis is the actual operating voltage of the electric water pump. Each cell in the matrix is ​​the maximum allowable operating current (i.e., the current threshold) under the corresponding "speed and voltage" conditions.

[0047] Taking a preset duration of 500ms as an example, when the current abnormality condition changes from not being met (0) to being met (1), the delay module starts timing due to the rising edge trigger. If the current abnormality lasts for 500ms, that is, the delay module continues timing until 500ms, then the pump will be judged to be stalled, so as to avoid misjudgment caused by short-term fluctuations in current.

[0048] 102. If the electric water pump is currently in a stall state, under normal engine operation, the engine ECU sends a first speed value to the electric water pump to control the electric water pump to stop running; after the electric water pump stops running for a first period of time, a second speed value is sent to the electric water pump, and fault counting is performed.

[0049] It should be noted that the first speed value is the target speed when the electronic water pump experiences a speed malfunction, and the second speed value is the target speed when the electronic water pump is operating normally. The first speed value is zero.

[0050] This step is used to attempt to eliminate the fault by requesting the water pump to start and stop while the engine is running normally, and to count the faults.

[0051] In this embodiment, when it is determined that the electronic water pump is currently in a stall state (i.e., the water pump speed fault flag WaPmp_bSpdErr_U8=1), the engine ECU will send the target speed WaPmp_SpdErr_C when the electronic water pump has a speed fault to the electronic water pump to control the electronic water pump to stop running, so as to achieve fault reset.

[0052] At the instant WaPmp_bSpdErr_U8 jumps from 1 (stall) to 0 (reset), the delay module starts timing due to the falling edge trigger. Within the calibrated duration WaPmp_tSpdReqUFlt_C (i.e. the first duration), the electronic water pump maintains zero speed to allow buffer time for the electronic water pump to recover from the fault.

[0053] For example, the first duration is 3 seconds, but this application does not limit it.

[0054] After the 3-second delay, the engine ECU sends the target operating speed WaPmp_SpdDsrBfFD to the electric water pump to allow it to return to normal operation. During this cycle, the fault count increases once. This fault count is used to determine the frequency of fault occurrences; if the fault count is too high, a higher level of protection needs to be triggered.

[0055] 103. If the engine ECU determines that the engine shutdown conditions have been met based on the current engine coolant temperature and the cumulative number of faults, it will send a shutdown command to the engine and report the fault.

[0056] This step is used to determine whether the engine needs to be shut down based on the engine's current coolant temperature and the cumulative number of malfunctions.

[0057] If the water temperature SSTM_Tm ≤ the preset water temperature threshold WaPmp_TmThrd_C, and the cumulative number of faults WaPmp_NumSpdCaltFails_U8 ≥ the first threshold WaPmp_TrgLowThrd_C, then the engine shutdown condition has been met, and the fault needs to be eliminated by shutting down the engine. Alternatively, If the water temperature SSTM_Tm > the preset water temperature threshold WaPmp_TmThrd_C, and the cumulative number of faults WaPmp_NumSpdCaltFails_U8 ≥ the second threshold WaPmp_TrgHiThrd_C, then it is determined that the engine shutdown condition has been met, and the fault needs to be eliminated by shutting down the engine.

[0058] It should be noted that the first threshold is also referred to as the low-temperature fault threshold in this document, and the second threshold is also referred to as the high-temperature fault threshold. The low-temperature fault threshold is numerically greater than the high-temperature fault threshold. For example, the low-temperature fault threshold is 3, and the high-temperature fault threshold is 1; this application does not limit this. Furthermore, the preset water temperature threshold can be 80 degrees Celsius; this application also does not limit this.

[0059] In this embodiment of the application, after determining that the fault needs to be eliminated by requesting engine shutdown, the engine ECU will send an engine shutdown command WaPmp_bReqEngStop_U8 to control the engine to shut down.

[0060] In one possible implementation, fault reporting refers to outputting a component-level fault signal E_DEwpSpd indicating an abnormal pump speed via an RS flip-flop. The RS flip-flop has set and reset functions, enabling latching and holding of the fault signal. When the abnormal pump speed is determined (WaPmp_bSpdActFat=1), the set terminal of the RS flip-flop is triggered, causing it to output the component-level fault signal E_DEwpSpd.

[0061] Specifically, after the RS trigger outputs the component-level fault signal E_DEwpSpd, the fault switch signal FSW_EwpSpdErr is activated. That is, when the component-level fault signal E_DEwpSpd is latched by the RS trigger, the fault switch signal FSW_EwpSpdErr is activated (changing from 0 to 1). The activated fault switch signal FSW_EwpSpdErr is then sent to the EMS fault management module to instruct the module to upgrade the electric water pump speed fault to a target-level engine system-level fault according to the fault level determination rules.

[0062] 104. After the engine has been idle for two consecutive hours, the engine ECU will reset the accumulated number of faults to zero and send a start command to the engine to restart it.

[0063] This step is used to request engine restart after a period of time following a complete engine shutdown.

[0064] When the engine receives a shutdown command and comes to a complete stop, the engine ECU starts timing. When the shutdown duration reaches the preset restart interval WaPmp_tFonDly_C (i.e., the second duration), the engine ECU will clear the accumulated number of faults WaPmp_NumSpdCaltFails_U8 and send an engine start command to attempt to restart the engine in order to verify whether the speed fault of the electronic water pump has been recovered after shutdown.

[0065] For example, the second duration is 0.3s, but this application does not limit it.

[0066] It should be noted that after the engine restarts, if the electric water pump has returned to normal operation, it will be controlled to operate at the second speed value, operating at the target speed during normal operation. If the electric water pump has not yet returned to normal operation, steps 102-104 above will be repeated to clear the fault. That is, the fault clearing operation of sending the first speed value to the electric water pump, sending the second speed value to the electric water pump, sending a stop command to the engine when the engine stop condition has been met, and restarting the engine will be performed again. If the electric water pump still has not returned to normal operation after multiple consecutive (e.g., three consecutive) fault clearing operations, the electric water pump will automatically report a stall fault. For example, the reporting target of the electric water pump is the vehicle controller or EMS, which is not limited in this application.

[0067] In summary, the stall control scheme for the electronic water pump provided in this application proposes an automatic and targeted control strategy that can quickly and effectively restore the electronic water pump from a stall state to normal operation. Specifically, when a stall phenomenon is determined based on the actual operating current of the electronic water pump and the current during normal operation, the scheme first attempts to eliminate the fault by controlling the electronic pump to stop operating while the engine is running normally, and counts the faults. Next, the scheme determines whether the engine needs to be shut down based on the current engine temperature and the accumulated number of faults. If an engine shutdown is required, the engine is shut down and a fault report is simultaneously submitted. Furthermore, after the engine has been shut down for a period of time, the scheme attempts to restart the engine to verify whether the speed fault of the electronic water pump has been resolved after shutdown. Because this scheme promptly eliminates and reports the fault after confirming a stall phenomenon, it avoids the risk of the engine being in a state of poor heat dissipation for a prolonged period, which not only extends the engine's service life and improves its operational reliability but also ensures the safety of the entire vehicle.

[0068] Figure 2 This is a schematic diagram of the stall control device for an electronic water pump provided in an embodiment of this application. See also... Figure 2 The device includes: The acquisition module 201 is configured to acquire the actual operating current of the electronic water pump; The determining module 202 is configured to determine the current operating state of the electronic water pump based on the actual operating current and the current threshold; the current threshold is the current value required for the electronic water pump to operate normally. Control module 203 is configured to send a first speed value to the electronic water pump when the engine is running normally, if the electronic water pump is currently in a stall state, in order to control the electronic water pump to stop operating; the first speed value is the target speed when the electronic water pump experiences a speed failure. The control module 203 is also configured to send a second speed value to the electronic water pump and perform fault counting after the electronic water pump stops operating for a first period of time; the second speed value is the target speed of the electronic water pump when it is operating normally. The control module 203 is also configured to send a shutdown command to the engine and report the fault if it is determined that the engine shutdown conditions have been met based on the engine's current water temperature and the cumulative number of faults. The control module 203 is also configured to reset the accumulated number of faults to zero and send a start command to the engine to restart the engine after the engine has been idle for a second duration.

[0069] The stall control scheme for an electronic water pump provided in this application proposes an automatic and targeted control strategy that can quickly and effectively restore the electronic water pump from a stall state to normal operation. Specifically, when a stall phenomenon is determined based on the actual operating current of the electronic water pump and the current during normal operation, the scheme first attempts to eliminate the fault by controlling the electronic pump to stop operating while the engine is running normally, and counts the faults. Next, the scheme determines whether the engine needs to be shut down based on the current engine temperature and the accumulated number of faults. If the engine needs to be shut down, it will be shut down and a fault report will be submitted simultaneously. Furthermore, after the engine has been shut down for a period of time, the scheme will attempt to restart the engine to verify whether the speed fault of the electronic water pump has been resolved after shutdown. Because this scheme promptly eliminates the fault and reports it after confirming a stall phenomenon, it avoids the risk of the engine being in a state of poor heat dissipation for a long time, which not only extends the engine's service life and improves its operational reliability but also ensures the safety of the entire vehicle.

[0070] In one possible implementation, the determining module is configured as follows: Obtain the actual operating voltage and actual rotational speed of the electronic water pump; The current threshold is determined based on the actual operating voltage and the actual rotational speed; If the actual operating current is greater than the current threshold, and the abnormal current condition lasts for at least a preset duration, it is determined that the electronic water pump is currently in the stall state.

[0071] In another possible implementation, the control module 203 is also configured as follows: If the current water temperature of the engine is less than or equal to a preset water temperature threshold, and the cumulative number of faults is greater than or equal to a first threshold, it is determined that the engine shutdown condition has been met.

[0072] In another possible implementation, the control module 203 is also configured as follows: If the current water temperature of the engine is greater than a preset water temperature threshold, and the cumulative number of faults is greater than or equal to a second threshold, it is determined that the engine shutdown condition has been met; wherein, the second threshold is less than the first threshold.

[0073] In another possible implementation, the control module 203 is also configured as follows: The component-level fault signal indicating abnormal speed of the electronic water pump is output through the RS trigger; Specifically, after the RS trigger outputs the component-level fault signal, the fault switch signal is activated. The activated fault switch signal is sent to the fault management module of the engine management system to instruct the fault management module to upgrade the speed fault of the electronic water pump to the target level engine system-level fault according to the fault level determination rules.

[0074] In another possible implementation, the control module 203 is also configured as follows: After the engine restarts, if the electronic water pump has returned to normal operation, control the electronic water pump to operate according to the second speed value.

[0075] In another possible implementation, the control module 203 is also configured as follows: If the electronic water pump has not yet returned to normal operation, the fault clearance operation of sending the first speed value to the electronic water pump, sending the second speed value to the electronic water pump, and sending a shutdown command to the engine and restarting the engine when the engine shutdown condition has been met is executed again. If the electronic water pump fails to return to normal operation after multiple consecutive fault eliminations, the electronic water pump will automatically report a stall fault; the electronic water pump will report to the vehicle controller or engine management system.

[0076] All of the above-mentioned optional technical solutions can be combined in any way to form the optional embodiments of this application, and will not be described in detail here.

[0077] It should be noted that the stall control device for the electronic water pump provided in the above embodiments is only illustrated by the division of the above functional modules when generating videos. In practical applications, the above functions 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 above. In addition, the stall control device for the electronic water pump provided in the above embodiments and the stall control method embodiments for the electronic water pump belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0078] Figure 3This is a schematic diagram of the structure of an electronic control unit provided in an embodiment of this application.

[0079] In this embodiment, the electronic control unit 300 is an engine ECU. The electronic control unit 300 can vary considerably depending on its configuration or performance, and may include one or more microprocessors 301 and one or more memories 302.

[0080] The memory 302 stores at least one piece of program code, which is loaded and executed by the microprocessor 301 to implement the stall control method of the above-mentioned electronic water pump.

[0081] In addition, the electronic control unit 300 also has input / output interfaces for input and output, enabling sensor signal acquisition and actuator command output. Furthermore, the electronic control unit 300 includes other components for realizing the device's functions, such as a power supply module, which will not be elaborated upon here. These are the physical basis for the realization of EMS functions.

[0082] In some embodiments, this application also provides a computer-readable storage medium, such as a memory including program code, which can be executed by a microprocessor in an electronic control unit to complete the stall control method of the electronic water pump described above. For example, the computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc read-only memory (CD-ROM), magnetic tape, floppy disk, and optical data storage device, etc.

[0083] In some embodiments, this application also provides a computer program product, which includes computer program code stored in a computer-readable storage medium. The microprocessor of the electronic control unit reads the computer program code from the computer-readable storage medium and executes the computer program code, causing the electronic control unit to execute the above-described stall control method for the electronic water pump.

[0084] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0085] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A stall control method of an electric water pump, characterized by, The method comprises: acquiring an actual working current of the electronic water pump, and determining a current working state of the electronic water pump according to the actual working current and a current threshold value; the current threshold value is a current value required by the electronic water pump when working normally; if the electronic water pump is currently in a stall state, sending a first rotating speed value to the electronic water pump to control the electronic water pump to stop running under the condition that the engine is running normally; the first rotating speed value is a target rotating speed when the electronic water pump has a rotating speed fault; after the electronic water pump stops running for a first time length, sending a second rotating speed value to the electronic water pump and counting faults; the second rotating speed value is a target rotating speed when the electronic water pump works normally; if it is determined that an engine shutdown condition has been reached according to a current water temperature of the engine and the cumulative number of faults, sending a shutdown instruction to the engine and reporting faults; after a shutdown time length of the engine reaches a second time length, clearing the cumulative number of faults and sending a start instruction to the engine to restart the engine.

2. The method of claim 1, wherein, The method further comprises: acquiring an actual working voltage and an actual rotating speed of the electronic water pump; determining the current threshold value according to the actual working voltage and the actual rotating speed; if the actual working current is greater than the current threshold value and a current abnormality lasts for at least a preset time length, it is determined that the electronic water pump is currently in the stall state.

3. The method of claim 1, wherein, The method further comprises: if the current water temperature of the engine is less than or equal to a preset water temperature threshold value and the cumulative number of faults is greater than or equal to a first threshold value, it is determined that the engine shutdown condition has been reached.

4. The method of claim 1, wherein, The method further comprises: if the current water temperature of the engine is greater than the preset water temperature threshold value and the cumulative number of faults is greater than or equal to a second threshold value, it is determined that the engine shutdown condition has been reached; the second threshold value is less than the first threshold value.

5. The method of claim 1, wherein, The method further comprises: outputting a component-level fault signal of the electronic water pump having a rotating speed abnormality through an RS flip-flop; wherein after the RS flip-flop outputs the component-level fault signal, a fault switch signal is activated, and the activated fault switch signal is sent to a fault management module of an engine management system to instruct the fault management module to upgrade the rotating speed fault of the electronic water pump to an engine system-level fault of a target level according to a fault level determination rule.

6. The method according to any one of claims 1 to 5, characterized in that, The method further comprises: after the engine is restarted, if the electronic water pump has returned to a normal running state, controlling the electronic water pump to run according to the second rotating speed value.

7. The method of claim 6, wherein, The method further comprises: if the electronic water pump has not returned to the normal running state, performing again the fault elimination operations of sending the first rotating speed value to the electronic water pump, sending the second rotating speed value to the electronic water pump, sending the shutdown instruction to the engine when the engine shutdown condition has been reached, and restarting the engine. If the electronic water pump has not returned to the normal operating state after continuous failure elimination, the electronic water pump will report a locked-rotor failure by itself; and the reporting object of the electronic water pump is a vehicle controller or an engine management system.

8. A stall control device for an electric water pump, characterized by The device comprises: An acquisition module configured to acquire an actual working current of the electronic water pump; A determination module configured to determine a current working state of the electronic water pump according to the actual working current and a current threshold value; the current threshold value is a current value required by the electronic water pump in normal working state; A control module configured to, if the electronic water pump is currently in a stall state, send a first rotating speed value to the electronic water pump to control the electronic water pump to stop running under the condition that the engine is in normal operation; the first rotating speed value is a target rotating speed when the electronic water pump has a rotating speed failure; The control module is further configured to, after the electronic water pump stops running for a first time length, send a second rotating speed value to the electronic water pump and perform failure counting; the second rotating speed value is a target rotating speed when the electronic water pump is in normal working state; The control module is further configured to, if it is determined that an engine shutdown condition has been reached according to a current water temperature of the engine and the accumulated failure number, send a shutdown instruction to the engine and perform failure reporting; The control module is further configured to, after a shutdown time length of the engine reaches a second time length, clear the accumulated failure number and send a start instruction to the engine to restart the engine.

9. An electronic control unit, characterized by The device comprises a microprocessor and a memory, and the memory stores at least one program code; the at least one program code is loaded and executed by the microprocessor to implement the stall control method of the electronic water pump according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The storage medium stores at least one program code; the at least one program code is loaded and executed by a microprocessor to implement the stall control method of the electronic water pump according to any one of claims 1 to 7.

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