Vehicle thermal management system fault diagnosis method, device, equipment and storage medium

Abstract

The present invention belongs to the field of fault diagnosis technology, and discloses a vehicle thermal management system fault diagnosis method, device, equipment and storage medium. The present invention obtains the driving speed of the vehicle when the vehicle is started, determines the current driving state according to the driving speed, and controls the thermal management system to operate according to a preset duty cycle when the driving state meets the diagnostic conditions, and enters the diagnostic mode. When entering the diagnostic mode, the current working condition of the vehicle is obtained, and the current working condition is input into the thermal management agent model of the whole vehicle to obtain the water temperature simulation value of the vehicle, and the water temperature simulation value is compared with the actual value obtained by detecting the water temperature through the temperature sensor, and the fault type is judged according to the comparison result. Compared with the prior art, it can avoid the shortcomings caused by using the highest temperature as the evaluation standard, and at the same time, the simulation value of the thermal management agent model is used as the benchmark for evaluation, rather than the empirical value, so that the fault recognition rate of the cooling system is higher.

Description

Technical Field

[0001] The present invention relates to the field of fault diagnosis technology, and in particular to a vehicle thermal management system fault diagnosis method, device, equipment and storage medium. Background Art

[0002] The motors, water pumps and other components in the thermal management system of new energy vehicles usually have their own faults and health status identified by diagnostic programs, but the coolant flow channels (including cooling pipes, water-cooled plate pipes, etc.) and heat exchange cores (including radiators, chillers, etc.) in the thermal management system are difficult to diagnose. At present, the maximum temperature of the components to be cooled is usually used as the input value for fault diagnosis of the thermal management system of new energy vehicles. The maximum temperature at this time may be the local temperature or the result after algorithm processing, and it is extremely dependent on the experience summary of technicians and lacks versatility for vehicles and environments.

[0003] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0004] The main purpose of the present invention is to provide a vehicle thermal management system fault diagnosis method, device, equipment and storage medium, aiming to solve the technical problems that the fault diagnosis of the prior art uses the maximum temperature as the input value for detection and relies on the experience of technicians, resulting in inaccurate diagnostic results and lack of versatility.

[0005] To achieve the above object, the present invention provides a vehicle thermal management system fault diagnosis method, the method comprising the following steps:

[0006] When the vehicle is started, obtaining the driving speed of the vehicle, and determining the current driving state according to the driving speed;

[0007] When the driving state meets the diagnostic condition, the thermal management system is controlled to operate according to a preset duty cycle and enter a diagnostic mode;

[0008] When entering the diagnostic mode, obtaining the current operating condition of the vehicle, inputting the current operating condition into the vehicle thermal management agent model, and obtaining a water temperature simulation value of the vehicle;

[0009] The water temperature simulation value is compared with the actual value obtained by detecting the water temperature through the temperature sensor, and the fault type is determined according to the comparison result.

[0010] Optionally, before obtaining whether the driving state of the vehicle satisfies a diagnosis condition, the method further includes:

[0011] Acquire environmental parameters and vehicle operating parameters in the vehicle bus, wherein the environmental parameters include at least air temperature, passenger compartment temperature, light intensity, and rainfall, and the vehicle operating parameters include at least vehicle speed, active grille opening, fan voltage, fan current, blower voltage, blower current, water pump opening, water valve opening, SOC, power battery current, power battery voltage, electric drive current, electric drive voltage, electric drive torque, electric drive speed, air conditioning setting, and vehicle mode;

[0012] A whole vehicle thermal management agent model is generated according to the environmental parameters and the vehicle operating condition parameters based on a preset model building method.

[0013] Optionally, the water temperature simulation value includes a simulated value of the electric drive radiator water inlet temperature, a simulated value of the electric drive radiator water outlet temperature, a simulated value of the coolant inlet temperature, and a simulated value of the coolant outlet temperature, and the actual value includes an actual value of the electric drive radiator water inlet temperature after cooling, an actual value of the electric drive radiator water outlet temperature after cooling, an actual value of the coolant inlet temperature, and an actual value of the coolant outlet temperature, and comparing the water temperature simulation value with an actual value obtained by detecting the water temperature through a temperature sensor, and judging the fault type according to the comparison result, includes:

[0014] Obtaining a simulated temperature difference of the electric drive radiator according to a simulated value of an inlet water temperature of the electric drive radiator and a simulated value of an outlet water temperature of the electric drive radiator;

[0015] Obtaining a difference in the actual water inlet temperature of the electric drive radiator after cooling according to the actual value of the water inlet temperature of the electric drive radiator after cooling and the simulated value of the water inlet temperature of the electric drive radiator;

[0016] When the actual water inlet temperature difference of the electric drive radiator after cooling is greater than or equal to the maximum value of the preset ratio of the simulated temperature difference of the electric drive radiator and the first preset parameter, the actual inlet and outlet water temperature difference of the electric drive radiator is obtained according to the actual value of the water inlet temperature of the electric drive radiator after cooling and the actual value of the water outlet temperature of the electric drive radiator after cooling;

[0017] When the temperature difference between the actual inlet and outlet water temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator is greater than or equal to a second preset parameter, the actual temperature difference of the coolant is calculated according to the actual temperature value of the coolant inlet and the actual temperature value of the coolant outlet, and the simulated temperature difference of the coolant is calculated according to the simulated temperature value of the coolant inlet and the simulated temperature value of the coolant outlet;

[0018] The temperature difference between the actual temperature difference of the coolant and the simulated temperature difference of the coolant and the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator are compared. When the difference between the actual temperature difference of the coolant and the simulated temperature difference of the coolant is greater than or equal to the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator, the thermal state of the component is abnormal.

[0019] Optionally, after obtaining the actual inlet and outlet water temperature difference of the electric drive radiator according to the actual value of the inlet water temperature of the cooled electric drive radiator and the actual value of the outlet water temperature of the cooled electric drive radiator, the method further includes:

[0020] When the temperature difference between the actual value of the inlet water temperature of the electric drive radiator after cooling and the simulated value of the inlet water temperature of the electric drive radiator is less than the larger value of the preset ratio of the simulated temperature difference of the electric drive radiator and the first preset parameter, the power of the cooling fan at the preset duty cycle and the actual power of the cooling fan are obtained;

[0021] The ratio of the actual power of the cooling fan to the power of the cooling fan at a preset duty cycle is compared with a third preset parameter. When the difference between the actual power of the cooling fan and the power of the cooling fan at the preset duty cycle is greater than or equal to the third preset parameter, the output front-end module heat dissipation core is abnormally blocked or the active grille position is abnormal.

[0022] Optionally, after comparing the ratio of the actual power of the cooling fan to the power of the cooling fan at a preset duty cycle with a third preset parameter, the method further includes:

[0023] When the difference between the actual power of the cooling fan and the power of the cooling fan at a preset duty cycle is less than a third preset parameter, the integrity of the flow guide and sealing structure of the output front-end module is abnormal.

[0024] Optionally, after comparing whether the temperature difference between the actual temperature difference of the coolant and the simulated temperature difference of the coolant is greater than or equal to the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator, the method further includes:

[0025] Comparing the actual value of the temperature of the coolant inlet with the simulated value of the temperature of the coolant inlet;

[0026] Comparing the actual value of the temperature of the coolant outlet with the simulated value of the temperature of the coolant outlet;

[0027] When the actual value of the temperature at the coolant inlet is greater than or equal to the simulated value of the temperature at the coolant inlet, and the actual value of the temperature at the coolant outlet is equal to the simulated value of the temperature at the coolant outlet, the output cooling circuit flow is abnormal;

[0028] Otherwise, the output cooling pipeline or the components without temperature sensors in the cooling circuit are abnormal.

[0029] Optionally, after comparing the water temperature simulation value with an actual value obtained by detecting the water temperature through a temperature sensor and determining the fault type according to the comparison result, the method further includes:

[0030] Select a corresponding prompt method according to the fault type;

[0031] The vehicle owner is prompted to understand the fault type of the vehicle according to the prompting method.

[0032] In addition, to achieve the above-mentioned purpose, the present invention also proposes a vehicle thermal management system fault diagnosis device, the vehicle thermal management system fault diagnosis device comprising:

[0033] A state detection module, used to obtain the driving speed of the vehicle when the vehicle is started, and determine the current driving state according to the driving speed;

[0034] A diagnosis entry module, used to control the thermal management system to operate according to a preset duty cycle and enter a diagnosis mode when the driving state meets the diagnosis condition;

[0035] A temperature simulation module, used for obtaining the current working condition of the vehicle when entering the diagnostic mode, inputting the current working condition into the vehicle thermal management agent model, and obtaining a water temperature simulation value of the vehicle;

[0036] The fault diagnosis module is used to compare the water temperature simulation value with the actual value obtained by detecting the water temperature through the temperature sensor, and determine the fault type according to the comparison result.

[0037] In addition, to achieve the above-mentioned objectives, the present invention also proposes a vehicle thermal management system fault diagnosis device, which includes: a memory, a processor, and a vehicle thermal management system fault diagnosis program stored in the memory and executable on the processor, and the vehicle thermal management system fault diagnosis program is configured to implement the steps of the vehicle thermal management system fault diagnosis method described above.

[0038] In addition, to achieve the above-mentioned purpose, the present invention also proposes a storage medium, on which a vehicle thermal management system fault diagnosis program is stored. When the vehicle thermal management system fault diagnosis program is executed by a processor, the steps of the vehicle thermal management system fault diagnosis method described above are implemented.

[0039] The present invention obtains the driving speed of the vehicle when the vehicle is started, determines the current driving state according to the driving speed, and when the driving state meets the diagnostic conditions, controls the thermal management system to operate according to a preset duty cycle to enter a diagnostic mode. When entering the diagnostic mode, the current operating condition of the vehicle is obtained, and the current operating condition is input into a thermal management agent model of the whole vehicle to obtain a water temperature simulation value of the vehicle, and the water temperature simulation value is compared with the actual value obtained by detecting the water temperature through a temperature sensor, and the fault type is judged according to the comparison result. Compared with the prior art, the shortcomings caused by using the highest temperature as the evaluation standard can be avoided, and at the same time, the simulation value of the thermal management agent model is used as a benchmark for evaluation, rather than an empirical value, so that the fault recognition rate of the cooling system is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a structural schematic diagram of a vehicle thermal management system fault diagnosis device in a hardware operating environment involved in an embodiment of the present invention;

[0041] Figure 2 A schematic flow chart of a first embodiment of a vehicle thermal management system fault diagnosis method according to the present invention;

[0042] Figure 3 A schematic flow chart of a second embodiment of a vehicle thermal management system fault diagnosis method according to the present invention;

[0043] Figure 4 A diagnostic logic diagram of an embodiment of a vehicle thermal management system fault diagnosis method of the present invention;

[0044] Figure 5 This is a structural block diagram of the first embodiment of the vehicle thermal management system fault diagnosis device of the present invention.

[0045] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0046] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0047] Reference Figure 1 , Figure 1 The present invention is a schematic diagram of the structure of a vehicle thermal management system fault diagnosis device in the hardware operating environment involved in the embodiment of the present invention.

[0048] like Figure 1As shown, the vehicle thermal management system fault diagnosis device may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. Among them, the communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 may include a display screen (Display), an input unit such as a keyboard (Keyboard), and the optional user interface 1003 may also include a standard wired interface and a wireless interface. The network interface 1004 may optionally include a standard wired interface and a wireless interface (such as a wireless fidelity (Wireless-Fidelity, Wi-Fi) interface). The memory 1005 may be a high-speed random access memory (Random Access Memory, RAM), or a stable non-volatile memory (Non-Volatile Memory, NVM), such as a disk storage. The memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0049] Those skilled in the art will understand that Figure 1 The structure shown in the figure does not constitute a limitation on the vehicle thermal management system fault diagnosis device, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0050] like Figure 1 As shown, the memory 1005 as a storage medium may include an operating system, a network communication module, a user interface module, and a vehicle thermal management system fault diagnosis program.

[0051] exist Figure 1 In the vehicle thermal management system fault diagnosis device shown, the network interface 1004 is mainly used for data communication with the network server; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the vehicle thermal management system fault diagnosis device of the present invention can be set in the vehicle thermal management system fault diagnosis device, and the vehicle thermal management system fault diagnosis device calls the vehicle thermal management system fault diagnosis program stored in the memory 1005 through the processor 1001, and executes the vehicle thermal management system fault diagnosis method provided by the embodiment of the present invention.

[0052] The embodiment of the present invention provides a vehicle thermal management system fault diagnosis method, referring to Figure 2 , Figure 2 The figure is a flow chart of a first embodiment of a vehicle thermal management system fault diagnosis method according to the present invention.

[0053] In this embodiment, the vehicle thermal management system fault diagnosis method includes the following steps:

[0054] Step S10: When the vehicle is started, the driving speed of the vehicle is obtained, and the current driving state is determined according to the driving speed.

[0055] It should be noted that the executor of this embodiment is a vehicle thermal management system fault diagnosis device, wherein the vehicle thermal management system fault diagnosis device has functions such as data processing, data communication and program running. The vehicle thermal management system fault diagnosis device can be an integrated controller, a control computer and other devices, and of course it can also be other devices with similar functions, and this embodiment does not limit this.

[0056] It is understandable that when the vehicle is started, the vehicle's speed can be obtained through the sensor. By monitoring the vehicle's speed, the vehicle's state can be determined. For example, the acceleration of the current vehicle can be determined by determining the speed increment per unit time. If the absolute value of the acceleration is greater than a preset threshold, it can be determined that the vehicle is in a state of rapid acceleration and deceleration. Therefore, the current driving state of the vehicle can be determined based on the vehicle's speed, and the current working mode of the battery can be determined by the driving state. Only when the vehicle is in a relatively stable driving mode, the abnormal diagnosis result of the battery is of reference value.

[0057] In the specific implementation, each time the vehicle is started, the vehicle's driving speed is obtained through the sensor, and the timing is started at the same time when the speed is counted to determine whether the current vehicle meets the diagnostic conditions. For example, if the diagnostic condition of the vehicle is that the average speed is greater than or equal to 30km / h within 20s and is not in a state of sudden acceleration or deceleration, the diagnostic program is started. Therefore, when performing speed detection, if the average speed within 20s does not reach the set 30km / h, it means that the current vehicle is in low-speed mode, or if there is a sudden acceleration or deceleration state within 20s, it is necessary to restart the timing and detect the speed state. The diagnostic conditions are set to avoid the influence of the vehicle on the vehicle when the distance to the front vehicle is too low and the influence of strong transient conditions on the diagnostic program.

[0058] Step S20: When the driving state meets the diagnostic condition, the thermal management system is controlled to operate according to a preset duty cycle and enter a diagnostic mode.

[0059] It should be noted that controlling the thermal management system to operate according to a preset duty cycle refers to controlling the electronic water pump to operate according to the duty cycle η and the cooling fan to operate according to the duty cycle θ. Taking the electric drive circuit as an example, the duty cycle of the electric drive circuit water pump is specified to be 90%, and the duty cycle of the fan is specified to be 60%. If the electric drive circuit has a proportional valve, the position of the proportional valve is controlled so that all the coolant passes through the front radiator.

[0060] Step S30: when entering the diagnostic mode, the current operating condition of the vehicle is obtained, and the current operating condition is input into the vehicle thermal management agent model to obtain a water temperature simulation value of the vehicle.

[0061] In a specific implementation, when the vehicle enters the diagnostic mode, the current working condition of the vehicle can be obtained, specifically, environmental parameters and vehicle working condition parameters are obtained from the vehicle bus signal, wherein the environmental parameters include at least air temperature, passenger compartment temperature, light intensity, and rainfall, and the vehicle working condition parameters include at least vehicle speed, active grille opening, fan voltage, fan current, blower voltage, blower current, water pump opening, water valve opening, SOC, power battery current, power battery voltage, electric drive current, electric drive voltage, electric drive torque, electric drive speed, air conditioning setting, and vehicle mode. The current working condition of the vehicle is input into the vehicle thermal management agent model to obtain the water temperature simulation value of the current working condition of the vehicle, wherein the water temperature simulation value includes the simulation values ​​of the inlet and outlet water temperatures of the electric drive radiator, which are T respectively. in and T out The simulated values ​​of the coolant inlet and outlet temperatures are T a1 and T a2 .

[0062] Furthermore, in order to obtain the vehicle thermal management agent model, it also includes:

[0063] Acquire environmental parameters and vehicle operating parameters in the vehicle bus, wherein the environmental parameters include at least air temperature, passenger compartment temperature, light intensity, and rainfall, and the vehicle operating parameters include at least vehicle speed, active grille opening, fan voltage, fan current, blower voltage, blower current, water pump opening, water valve opening, SOC, power battery current, power battery voltage, electric drive current, electric drive voltage, electric drive torque, electric drive speed, air conditioning setting, and vehicle mode;

[0064] A whole vehicle thermal management agent model is generated according to the environmental parameters and the vehicle operating condition parameters based on a preset model building method.

[0065] In the specific implementation, through certain mathematical methods, such as polynomial response surface model RSM, Kriging model, radial basis function model RBF, neural network model NN, etc., a proxy model of the whole vehicle thermal management performance simulation model or a proxy model of the local thermal management system can be generated. The proxy model has high calculation accuracy, low computing resource requirements, and fast calculation speed, and the vehicle-mounted processor can be used to complete the calculation.

[0066] Step S40: Compare the water temperature simulation value with the actual value obtained by detecting the water temperature through the temperature sensor, and determine the fault type according to the comparison result.

[0067] It should be noted that the actual value is the temperature value obtained by detecting the water temperature through a temperature sensor, and is a value that can truly reflect the temperature conditions of the water temperature.

[0068] In the specific implementation, the water temperature results output by the simulation calculation are compared with the results collected by the vehicle temperature sensor, and the fault and health status diagnosis is performed according to the strategy. This evaluation method is more direct and avoids the influence of the local temperature measurement points of the components on the evaluation accuracy. By comparing the simulation values ​​of the inlet and outlet water temperatures of the electric drive radiator, which are T in and T out The simulated values ​​of the coolant inlet and outlet temperatures are T a1 and T a2 The actual values ​​of the water inlet and outlet temperatures of the electric drive radiator are T in ′ and T o ' ut The actual values ​​of the coolant inlet and outlet temperatures are T a ' 1 and T a ' 2 The relationship between can be used to obtain the current battery fault type.

[0069] Furthermore, after comparing the water temperature simulation value with the actual value obtained by detecting the water temperature through the temperature sensor and determining the fault type according to the comparison result, the method further includes:

[0070] Select a corresponding prompt method according to the fault type;

[0071] The vehicle owner is prompted to understand the fault type of the vehicle according to the prompting method.

[0072] In the specific implementation, after determining the fault type, the fault prompt method can be determined according to the different fault types, such as the flashing changes of the indicator light and the corresponding text display, etc., to remind the owner of the fault in the thermal management system and the corresponding fault type at this time, thereby protecting the owner's driving safety.

[0073] This embodiment obtains the driving speed of the vehicle when the vehicle is started, determines the current driving state according to the driving speed, and controls the thermal management system to operate according to a preset duty cycle when the driving state meets the diagnostic conditions to enter the diagnostic mode. When entering the diagnostic mode, the current operating condition of the vehicle is obtained, and the current operating condition is input into the thermal management agent model of the whole vehicle to obtain a water temperature simulation value of the vehicle, and the water temperature simulation value is compared with the actual value obtained by detecting the water temperature through a temperature sensor, and the fault type is determined according to the comparison result. Compared with the prior art, this embodiment can avoid the shortcomings caused by using the highest temperature as the evaluation standard, and at the same time, the simulation value of the thermal management agent model is used as a benchmark for evaluation, rather than an empirical value, so the fault recognition rate of the cooling system is higher.

[0074] refer to Figure 3 , Figure 3 The figure is a flow chart of a second embodiment of a vehicle thermal management system fault diagnosis method according to the present invention.

[0075] Based on the above first embodiment, the vehicle thermal management system fault diagnosis method of this embodiment includes in step S40:

[0076] Step S401: obtaining a simulated temperature difference of the electric drive radiator according to a simulated value of the water inlet temperature of the electric drive radiator and a simulated value of the water outlet temperature of the electric drive radiator;

[0077] Step S402: obtaining a difference in the actual inlet water temperature of the electric drive radiator after cooling according to the actual value of the inlet water temperature of the electric drive radiator after cooling and the simulated value of the inlet water temperature of the electric drive radiator;

[0078] Step S403: when the actual inlet water temperature difference of the electric drive radiator after cooling is greater than or equal to the maximum value of the preset ratio of the simulated temperature difference of the electric drive radiator and the first preset parameter, the actual inlet and outlet water temperature difference of the electric drive radiator is obtained according to the actual value of the inlet water temperature of the electric drive radiator after cooling and the actual value of the outlet water temperature of the electric drive radiator after cooling;

[0079] Step S404: when the temperature difference between the actual inlet and outlet water temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator is greater than or equal to a second preset parameter, the actual temperature difference of the coolant is calculated according to the actual temperature value of the coolant inlet and the actual temperature value of the coolant outlet, and the simulated temperature difference of the coolant is calculated according to the simulated temperature value of the coolant inlet and the simulated temperature value of the coolant outlet;

[0080] Step S405: Compare the temperature difference between the actual temperature difference of the coolant and the simulated temperature difference of the coolant and the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator. When the difference between the actual temperature difference of the coolant and the simulated temperature difference of the coolant is greater than or equal to the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator, output that the thermal state of the component is abnormal.

[0081] In the specific implementation, refer to Figure 4 , Figure 4 The water temperature simulation value includes the simulation values ​​of the water inlet and outlet temperatures of the electric drive radiator, which are T in and T out The simulated values ​​of the coolant inlet and outlet temperatures are T a1 and T a2 The actual values ​​include the actual values ​​of the inlet and outlet water temperatures of the electric drive radiator after cooling, respectively T in ′ and T o ' ut The actual values ​​of the coolant inlet and outlet temperatures are T a ' 1 and T a ' 2 Taking the electric drive cooling circuit as an example, the simulation values ​​of the inlet and outlet water temperatures of the electric drive radiator are known to be T in and T out , the simulated temperature difference ΔT of the electric drive radiator can be obtained according to the simulated value of the water inlet temperature of the electric drive radiator and the simulated value of the water outlet temperature of the electric drive radiator 0 , where ΔT 0 =T in -T out , ΔT a =T a2 -T a1 , ΔT 0 ′=T in ′-T o ' ut , ΔT a ′=T a ' 2 -T a ' 1 The actual value of the inlet water temperature of the electric drive radiator after cooling and the simulated value of the inlet water temperature of the electric drive radiator are compared with the preset ratio of the difference between the actual inlet water temperature of the electric drive radiator after cooling and the simulated temperature difference of the electric drive radiator and the maximum value in the first preset parameter. The comparison formula is T in ′-T in ≥MAX(20%ΔT 0,2), when the formula is not satisfied, the current abnormal diagnosis program is terminated, and the battery is in normal state at this time. If the formula is satisfied, it means that the current battery is abnormal and needs further diagnosis. And further, according to the actual value of the inlet water temperature of the electric drive radiator after cooling and the actual value of the outlet water temperature of the electric drive radiator after cooling, the actual inlet and outlet water temperature difference ΔT of the electric drive radiator is obtained. 0 ', and further determine the relationship between the temperature difference between the actual inlet and outlet water temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator and the second preset parameter, and when ΔT is satisfied 0 ′-ΔT 0 ≥1.5, further diagnosis is required, and the temperature difference between the actual temperature difference of the coolant and the simulated temperature difference of the coolant and the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator are compared. The comparison formula is ΔT a ' 1 -ΔT a1 ≥ΔT 0 ′-ΔT 0 When, that is, when the difference between the actual temperature difference of the coolant and the simulated temperature difference of the coolant is greater than or equal to the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator, the thermal state of the output component is abnormal.

[0082] Further, after obtaining the actual inlet and outlet water temperature difference of the electric drive radiator according to the actual value of the inlet water temperature of the cooled electric drive radiator and the actual value of the outlet water temperature of the cooled electric drive radiator, the method further includes:

[0083] When the temperature difference between the actual value of the inlet water temperature of the electric drive radiator after cooling and the simulated value of the inlet water temperature of the electric drive radiator is less than the larger value of the preset ratio of the simulated temperature difference of the electric drive radiator and the first preset parameter, the power of the cooling fan at the preset duty cycle and the actual power of the cooling fan are obtained;

[0084] The ratio of the actual power of the cooling fan to the power of the cooling fan at a preset duty cycle is compared with a third preset parameter. When the difference between the actual power of the cooling fan and the power of the cooling fan at the preset duty cycle is greater than or equal to the third preset parameter, the output front-end module heat dissipation core is abnormally blocked or the active grille position is abnormal.

[0085] In a specific implementation, the magnitude relationship between the temperature difference between the actual inlet and outlet water temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator and the second preset parameter does not satisfy ΔT 0 ′-ΔT 0≥1.5, the power of the cooling fan needs to be judged. The corresponding power of the cooling fan at a duty cycle of 60% is P fan The power at this time is the simulated power. In actual situations, the duty cycle of the cooling fan is the same as the simulated conditions. At this time, the current signal I of the cooling fan, the voltage signal U, and the actual power P of the cooling fan are f ' an =UI, at this time, the simulation value of the cooling fan is compared with the actual value and the third preset parameter, specifically P f ' an / P fan ≥1.2, when the difference between the actual power of the cooling fan and the power of the cooling fan at the preset duty cycle is greater than or equal to the third preset parameter, P is satisfied. f ' an / P fan ≥1.2, the output front-end module heat dissipation core is abnormally blocked or the active grille position is abnormal.

[0086] Further, after comparing the ratio of the actual power of the cooling fan to the power of the cooling fan at a preset duty cycle with a third preset parameter, the method further includes:

[0087] When the difference between the actual power of the cooling fan and the power of the cooling fan at a preset duty cycle is less than a third preset parameter, the integrity of the flow guide and sealing structure of the output front-end module is abnormal.

[0088] In a specific implementation, the simulation value of the cooling fan is compared with the actual value, and when compared with the third preset parameter, if P is not satisfied, f ' an / P fan When ≥1.2, the output front-end module flow guidance and sealing structure integrity are abnormal.

[0089] Further, after comparing whether the temperature difference between the actual temperature difference of the coolant and the simulated temperature difference of the coolant is greater than or equal to the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator, it also includes:

[0090] Comparing the actual value of the temperature of the coolant inlet with the simulated value of the temperature of the coolant inlet;

[0091] Comparing the actual value of the temperature of the coolant outlet with the simulated value of the temperature of the coolant outlet;

[0092] When the actual value of the temperature at the coolant inlet is greater than or equal to the simulated value of the temperature at the coolant inlet, and the actual value of the temperature at the coolant outlet is equal to the simulated value of the temperature at the coolant outlet, the output cooling circuit flow is abnormal;

[0093] Otherwise, the output cooling pipeline or the components without temperature sensors in the cooling circuit are abnormal.

[0094] In a specific implementation, the temperature difference between the actual temperature difference of the coolant and the simulated temperature difference of the coolant is compared with the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator. If ΔT is not satisfied, a ' 1 -ΔT a1 ≥ΔT 0 ′-ΔT 0 When the actual value of the temperature at the coolant inlet is greater than or equal to the simulated value of the temperature at the coolant inlet, and the actual value of the temperature at the coolant outlet is greater than or equal to the simulated value of the temperature at the coolant inlet, and the actual value of the temperature at the coolant outlet is greater than or equal to the simulated value of the temperature at the coolant outlet, that is, (T a ' 1 ≥T a1 )∩(T a ' 2 ≥T a2 ), the output cooling circuit flow is abnormal; otherwise, the output cooling pipeline or the parts without temperature sensors in the cooling circuit are abnormal.

[0095] This embodiment compares and evaluates the water temperature value collected by the sensor and the temperature simulation value calculated by the thermal management agent model. The evaluation standard is more accurate, avoiding the shortcomings of using the temperature difference between the highest temperature of the component and the water temperature as the evaluation standard. The accuracy of identifying the fault and health of the cooling system is higher. At the same time, the simulation value of the thermal management agent model is used as a benchmark for evaluation rather than an empirical value, which has higher applicability. Moreover, the thermal management signal value can also be used to diagnose and identify a variety of common thermal management faults. In addition to diagnosing the status of components based on the inlet and outlet water temperatures of the components, faults without direct measurement signal feedback, such as front-end diversion, sealing, heat dissipation core obstruction, cooling pipeline abnormalities, and flow abnormalities, can also be diagnosed.

[0096] In addition, an embodiment of the present invention further proposes a storage medium, on which a vehicle thermal management system fault diagnosis program is stored. When the vehicle thermal management system fault diagnosis program is executed by a processor, the steps of the vehicle thermal management system fault diagnosis method described above are implemented.

[0097] Reference Figure 5 , Figure 5 This is a structural block diagram of the first embodiment of the vehicle thermal management system fault diagnosis device of the present invention.

[0098] like Figure 5As shown, the vehicle thermal management system fault diagnosis device proposed in the embodiment of the present invention includes:

[0099] The state detection module 10 is used to obtain the driving speed of the vehicle when the vehicle is started, and determine the current driving state according to the driving speed;

[0100] The diagnosis entry module 20 is used to control the thermal management system to operate according to a preset duty cycle and enter a diagnosis mode when the driving state meets the diagnosis condition;

[0101] The temperature simulation module 30 is used to obtain the current working condition of the vehicle when entering the diagnosis mode, input the current working condition into the vehicle thermal management agent model, and obtain the water temperature simulation value of the vehicle;

[0102] The fault diagnosis module 40 is used to compare the water temperature simulation value with the actual value obtained by detecting the water temperature through the temperature sensor, and determine the fault type according to the comparison result.

[0103] This embodiment obtains the driving speed of the vehicle when the vehicle is started, determines the current driving state according to the driving speed, and controls the thermal management system to operate according to a preset duty cycle when the driving state meets the diagnostic conditions to enter the diagnostic mode. When entering the diagnostic mode, the current operating condition of the vehicle is obtained, and the current operating condition is input into the thermal management agent model of the whole vehicle to obtain a water temperature simulation value of the vehicle, and the water temperature simulation value is compared with the actual value obtained by detecting the water temperature through a temperature sensor, and the fault type is determined according to the comparison result. Compared with the prior art, this embodiment can avoid the shortcomings caused by using the highest temperature as the evaluation standard, and at the same time, the simulation value of the thermal management agent model is used as a benchmark for evaluation, rather than an empirical value, so the fault recognition rate of the cooling system is higher.

[0104] In one embodiment, the diagnostic entry module 20 is also used to obtain environmental parameters and vehicle operating parameters in the vehicle bus, wherein the environmental parameters include at least air temperature, passenger compartment temperature, light intensity, and rainfall, and the vehicle operating parameters include at least vehicle speed, active grille opening, fan voltage, fan current, blower voltage, blower current, water pump opening, water valve opening, SOC, power battery current, power battery voltage, electric drive current, electric drive voltage, electric drive torque, electric drive speed, air conditioning settings, and vehicle mode; a whole vehicle thermal management agent model is generated according to the environmental parameters and the vehicle operating parameters based on a preset model construction method.

[0105] In one embodiment, the fault diagnosis module 40 is further used to obtain the simulated temperature difference of the electric drive radiator according to the simulated value of the electric drive radiator inlet water temperature and the simulated value of the electric drive radiator outlet water temperature; obtain the actual inlet water temperature difference of the cooled electric drive radiator according to the actual value of the cooled electric drive radiator inlet water temperature and the simulated value of the electric drive radiator inlet water temperature; when the actual inlet water temperature difference of the cooled electric drive radiator is greater than or equal to the maximum value of the preset ratio of the simulated temperature difference of the electric drive radiator and the first preset parameter, obtain the actual inlet and outlet water temperature difference of the electric drive radiator according to the actual value of the cooled electric drive radiator inlet water temperature and the actual value of the cooled electric drive radiator outlet water temperature; when the actual inlet and outlet water temperature difference of the electric drive radiator is greater than or equal to the preset ratio of the simulated temperature difference of the electric drive radiator and the maximum value of the first preset parameter, When the temperature difference of the simulated temperature difference of the electric drive radiator is greater than or equal to a second preset parameter, the actual temperature difference of the coolant is calculated according to the actual temperature value of the coolant inlet and the actual temperature value of the coolant outlet, and the simulated temperature difference of the coolant is obtained according to the simulation value of the temperature of the coolant inlet and the simulation value of the temperature of the coolant outlet; the temperature difference between the actual temperature difference of the coolant and the simulated temperature difference of the coolant and the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator are compared; when the difference between the actual temperature difference of the coolant and the simulated value difference of the coolant is greater than or equal to the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator, the thermal state of the output component is abnormal.

[0106] In one embodiment, the fault diagnosis module 40 is also used to obtain the power of the cooling fan at a preset duty cycle and the actual power of the cooling fan when the temperature difference between the actual value of the electric drive radiator water inlet temperature after cooling and the simulated value of the electric drive radiator water inlet temperature is less than the larger value of the preset ratio of the simulated temperature difference of the electric drive radiator and the first preset parameter; compare the ratio of the actual power of the cooling fan to the power of the cooling fan at the preset duty cycle with a third preset parameter, and when the difference between the actual power of the cooling fan and the power of the cooling fan at the preset duty cycle is greater than or equal to the third preset parameter, output that the front-end module heat dissipation core is abnormally blocked or the active grille position is abnormal.

[0107] In one embodiment, the fault diagnosis module 40 is further used to output that the front-end module guide and sealing structure integrity is abnormal when the difference between the actual power of the cooling fan and the power of the cooling fan at a preset duty cycle is less than a third preset parameter.

[0108] In one embodiment, the fault diagnosis module 40 is further used to compare the actual temperature value of the coolant inlet with the temperature simulation value of the coolant inlet; compare the actual temperature value of the coolant outlet with the temperature simulation value of the coolant outlet; when the actual temperature value of the coolant inlet is greater than or equal to the temperature simulation value of the coolant inlet, and the actual temperature value of the coolant outlet is the same as the temperature simulation value of the coolant outlet, output that the cooling circuit flow is abnormal; otherwise, output that the cooling pipeline or the component without temperature sensor in the cooling circuit is abnormal.

[0109] In one embodiment, the fault diagnosis module 40 is further used to select a corresponding prompt method according to the fault type; and prompt the vehicle owner to understand the fault type of the vehicle according to the prompt method.

[0110] It should be understood that the above is only an example and does not constitute any limitation on the technical solution of the present invention. In specific applications, technicians in this field can make settings as needed, and the present invention does not limit this.

[0111] It should be understood that, although the various steps in the flowchart in the embodiment of the present application are displayed in sequence according to the indication of the arrows, these steps are not necessarily performed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and it can be performed in other orders. Moreover, at least a portion of the steps in the figure may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and their execution order is not necessarily performed in sequence, but can be performed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0112] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of the present invention. In practical applications, technicians in this field can select part or all of them according to actual needs to achieve the purpose of the present embodiment, and no limitation is made here.

[0113] In addition, it should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0114] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0115] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as a read-only memory (ROM) / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0116] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A vehicle thermal management system fault diagnosis method, characterized in that: The vehicle thermal management system fault diagnosis method comprises: When the vehicle is started, obtaining the driving speed of the vehicle, and determining the current driving state according to the driving speed; When the driving state meets the diagnostic condition, the thermal management system is controlled to operate according to a preset duty cycle and enter a diagnostic mode; When entering the diagnostic mode, obtaining the current operating condition of the vehicle, inputting the current operating condition into the vehicle thermal management agent model, and obtaining a water temperature simulation value of the vehicle; The water temperature simulation value is compared with the actual value obtained by detecting the water temperature through the temperature sensor, and the fault type is determined according to the comparison result. The water temperature simulation value includes the electric drive radiator water inlet temperature simulation value, the electric drive radiator water outlet temperature simulation value, the coolant inlet temperature simulation value and the coolant outlet temperature simulation value, the actual value includes the actual value of the electric drive radiator water inlet temperature after cooling and the actual value of the electric drive radiator water outlet temperature after cooling, the coolant inlet temperature actual value and the coolant outlet temperature actual value, and the water temperature simulation value is compared with the actual value obtained by detecting the water temperature through the temperature sensor, and the fault type is judged according to the comparison result, including: Obtaining a simulated temperature difference of the electric drive radiator according to a simulated value of an inlet water temperature of the electric drive radiator and a simulated value of an outlet water temperature of the electric drive radiator; Obtaining a difference in the actual water inlet temperature of the electric drive radiator after cooling according to the actual value of the water inlet temperature of the electric drive radiator after cooling and the simulated value of the water inlet temperature of the electric drive radiator; When the actual water inlet temperature difference of the electric drive radiator after cooling is greater than or equal to the maximum value of the preset ratio of the simulated temperature difference of the electric drive radiator and the first preset parameter, the actual inlet and outlet water temperature difference of the electric drive radiator is obtained according to the actual value of the water inlet temperature of the electric drive radiator after cooling and the actual value of the water outlet temperature of the electric drive radiator after cooling; When the temperature difference between the actual inlet and outlet water temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator is greater than or equal to a second preset parameter, the actual temperature difference of the coolant is calculated according to the actual temperature value of the coolant inlet and the actual temperature value of the coolant outlet, and the simulated temperature difference of the coolant is calculated according to the simulated temperature value of the coolant inlet and the simulated temperature value of the coolant outlet; The temperature difference between the actual temperature difference of the coolant and the simulated temperature difference of the coolant and the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator are compared. When the difference between the actual temperature difference of the coolant and the simulated temperature difference of the coolant is greater than or equal to the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator, the thermal state of the component is abnormal.

2. The method according to claim 1, characterized in that Before obtaining that the driving state of the vehicle meets the diagnosis condition, the method further includes: Acquire environmental parameters and vehicle operating parameters in the vehicle bus, wherein the environmental parameters include at least air temperature, passenger compartment temperature, light intensity, and rainfall, and the vehicle operating parameters include at least vehicle speed, active grille opening, fan voltage, fan current, blower voltage, blower current, water pump opening, water valve opening, SOC, power battery current, power battery voltage, electric drive current, electric drive voltage, electric drive torque, electric drive speed, air conditioning setting, and vehicle mode; A whole vehicle thermal management agent model is generated according to the environmental parameters and the vehicle operating condition parameters based on a preset model building method.

3. The method according to claim 1, characterized in that After obtaining the actual inlet and outlet water temperature difference of the electric drive radiator according to the actual value of the inlet water temperature of the cooled electric drive radiator and the actual value of the outlet water temperature of the cooled electric drive radiator, the method further includes: When the temperature difference between the actual value of the inlet water temperature of the electric drive radiator after cooling and the simulated value of the inlet water temperature of the electric drive radiator is less than the larger value of the preset ratio of the simulated temperature difference of the electric drive radiator and the first preset parameter, the power of the cooling fan at the preset duty cycle and the actual power of the cooling fan are obtained; The ratio of the actual power of the cooling fan to the power of the cooling fan at a preset duty cycle is compared with a third preset parameter. When the difference between the actual power of the cooling fan and the power of the cooling fan at the preset duty cycle is greater than or equal to the third preset parameter, the output front-end module heat dissipation core is abnormally blocked or the active grille position is abnormal.

4. The method according to claim 3, characterized in that After comparing the ratio of the actual power of the cooling fan to the power of the cooling fan at the preset duty cycle with the third preset parameter, the method further includes: When the difference between the actual power of the cooling fan and the power of the cooling fan at a preset duty cycle is less than a third preset parameter, the integrity of the flow guide and sealing structure of the output front-end module is abnormal.

5. The method according to claim 1, characterized in that After comparing whether the temperature difference between the actual temperature difference of the coolant and the simulated temperature difference of the coolant is greater than or equal to the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator, the method further includes: Comparing the actual value of the temperature of the coolant inlet with the simulated value of the temperature of the coolant inlet; Comparing the actual value of the temperature of the coolant outlet with the simulated value of the temperature of the coolant outlet; When the actual value of the temperature at the coolant inlet is greater than or equal to the simulated value of the temperature at the coolant inlet, and the actual value of the temperature at the coolant outlet is equal to the simulated value of the temperature at the coolant outlet, the output cooling circuit flow is abnormal; Otherwise, the output cooling pipeline or the components without temperature sensors in the cooling circuit are abnormal.

6. The method according to any one of claims 1 to 5, characterized in that After comparing the water temperature simulation value with the actual value obtained by detecting the water temperature through the temperature sensor and determining the fault type according to the comparison result, the method further includes: Select a corresponding prompt method according to the fault type; The vehicle owner is prompted to understand the fault type of the vehicle according to the prompting method.

7. A vehicle thermal management system fault diagnosis device, characterized in that: The vehicle thermal management system fault diagnosis device comprises: A state detection module, used to obtain the driving speed of the vehicle when the vehicle is started, and determine the current driving state according to the driving speed; A diagnosis entry module, used to control the thermal management system to operate according to a preset duty cycle and enter a diagnosis mode when the driving state meets the diagnosis condition; A temperature simulation module, used for obtaining the current working condition of the vehicle when entering the diagnostic mode, inputting the current working condition into the vehicle thermal management agent model, and obtaining a water temperature simulation value of the vehicle; A fault diagnosis module is used to obtain a simulated temperature difference of the electric drive radiator according to a simulated value of the inlet water temperature of the electric drive radiator and a simulated value of the outlet water temperature of the electric drive radiator; to obtain an actual inlet water temperature difference of the cooled electric drive radiator according to an actual value of the inlet water temperature of the cooled electric drive radiator and a simulated value of the inlet water temperature of the electric drive radiator; when the actual inlet water temperature difference of the cooled electric drive radiator is greater than or equal to a maximum value of a preset ratio of the simulated temperature difference of the electric drive radiator and a first preset parameter, to obtain an actual inlet and outlet water temperature difference of the electric drive radiator according to an actual value of the inlet water temperature of the cooled electric drive radiator and an actual value of the outlet water temperature of the cooled electric drive radiator; and when the actual inlet and outlet water temperature difference of the electric drive radiator is greater than or equal to a preset ratio of a simulated temperature difference of the electric drive radiator and a maximum value of a first preset parameter, When the temperature difference of the true temperature difference is greater than or equal to the second preset parameter, the actual temperature difference of the coolant is calculated according to the actual temperature value of the coolant inlet and the actual temperature value of the coolant outlet, and the simulated temperature difference of the coolant is obtained according to the temperature simulation value of the coolant inlet and the temperature simulation value of the coolant outlet; the temperature difference between the actual temperature difference of the coolant and the simulated temperature difference of the coolant and the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator are compared, and when the difference between the actual temperature difference of the coolant and the simulated temperature difference of the coolant is greater than or equal to the temperature difference between the actual temperature difference of the electric drive radiator and the simulated temperature difference of the electric drive radiator, the thermal state of the output component is abnormal.

8. A vehicle thermal management system fault diagnosis device, characterized in that: The device includes: a memory, a processor, and a vehicle thermal management system fault diagnosis program stored in the memory and executable on the processor, wherein the vehicle thermal management system fault diagnosis program is configured to implement the steps of the vehicle thermal management system fault diagnosis method as described in any one of claims 1 to 6.

9. A storage medium, characterized in that: The storage medium stores a vehicle thermal management system fault diagnosis program, which, when executed by a processor, implements the steps of the vehicle thermal management system fault diagnosis method according to any one of claims 1 to 6.

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