A control method and system for a cooling fan after engine shutdown of a vehicle

Abstract

The present application relates to the technical field of vehicle engine control, and particularly relates to a control method and system for a cooling fan after a vehicle engine is stopped. The present application controls the opening gear and opening time of the cooling fan based on the highest water temperature after the engine is stopped, and considers the reduction of electrical load energy consumption, carries out self-learning of fan control parameters, dynamically updates the fan control parameters, then controls the opening gear and opening time of the cooling fan based on the updated fan control parameters, and further reasonably allocates the electrical load, so that the engine coolant temperature can be effectively reduced, the service life of the engine is improved, and the overall energy consumption of the system is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle engine control, in particular to a control method and system for a cooling fan after a vehicle engine is stopped. BACKGROUND

[0002] After the engine of a vehicle is stopped, if the engine coolant temperature (engine water temperature) is too high, it will cause the wear and tear of each part of the engine to intensify, and in severe cases, it will cause permanent damage to the engine.

[0003] The existing engine cooling control scheme usually uses a cooling fan to continue to cool the engine, but the existing technology does not consider dynamic control according to the real-time performance of the cooling system, and does not balance the design from the perspective of protecting the service life of the engine and reducing the energy consumption of the electrical load, resulting in low efficiency and high energy consumption of the existing cooling system. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a control method and system for a cooling fan after a vehicle engine is stopped, which can effectively reduce the engine coolant temperature, improve the service life of the engine, and reduce the overall energy consumption of the system.

[0005] To solve the above technical problems, the technical solution adopted by the present application is:

[0006] I. A control method for a cooling fan after a vehicle engine is stopped

[0007] The present application provides a control method for a cooling fan after a vehicle engine is stopped, which includes a cooling fan step control method based on the highest water temperature after stopping and a cooling fan control parameter self-learning update method.

[0008] The cooling fan step control method based on the highest water temperature after stopping includes the following strategies:

[0009] S11, real-time record and update the highest water temperature of the coolant after the engine is stopped, and divide the highest water temperature into multiple intervals;

[0010] S12, real-time acquisition of the current atmospheric temperature and atmospheric pressure, and division of the atmospheric temperature and atmospheric pressure into multiple intervals;

[0011] S13, determining the initial running gear of the cooling fan according to the interval of the highest water temperature, and determining the initial running time of the cooling fan according to the interval of the atmospheric temperature and atmospheric pressure;

[0012] S14, step control of the cooling fan according to the initial running gear and initial running time.

[0013] Specifically as follows:

[0014] 1) Current highest water temperature is greater than the preset value A, then open the fan high speed gear, and the opening time is the preset time T1; The working condition under this condition is recorded as high speed opening working condition one;

[0015] 2) Current highest water temperature is not greater than the preset value A, and is greater than the preset value B, then open the fan high speed gear, and the opening time is the preset time T2; The working condition under this condition is recorded as high speed opening working condition two;

[0016] 3) Current highest water temperature is not greater than the preset value B, and is greater than the preset value C, then open the fan low speed gear, and the opening time is the preset time T3; The working condition under this condition is recorded as low speed opening working condition three;

[0017] 4) Current highest water temperature is not greater than the preset value C, and is greater than the preset value D, then open the fan low speed gear, and the opening time is the preset time T4; The working condition under this condition is recorded as low speed opening working condition four;

[0018] Among them, the preset value A > B > C > D, the preset time T1 > T2 > T3 > T4, and the values of the preset value and the preset time are dynamically updated according to the electrical load energy consumption.

[0019] The cooling fan control parameter self-learning updating method includes the following strategies:

[0020] S21, record the control parameter value of the cooling fan after each engine shutdown, judge whether the vehicle mileage under the condition of no control parameter updating exceeds the preset mileage, if yes, continue to execute the subsequent steps, if not, do not perform control parameter self-learning updating;

[0021] S22, record the engine cooling system working condition under the condition that only the cooling fan works after the engine stops and the system data under this working condition;

[0022] Among them, the system working condition includes: atmospheric temperature, atmospheric temperature, the highest water temperature of the cooling liquid, fan running gear; The system data includes: fan running time, cooling liquid temperature after the fan is turned off, the difference between the battery SOC when the engine stops and when the fan is turned off, the time difference between the cooling liquid temperature first reaching the preset water temperature and when the fan is turned off.

[0023] S23, when the same system working condition is encountered again, switch the current fan running working condition, and control the fan to stop running when the cooling liquid temperature reaches the cooling liquid temperature after the fan is turned off under the last same working condition; Record the current fan running time and the difference between the battery SOC when the engine stops and when the fan is turned off;

[0024] The switching fan operation condition is specifically: if the last time is the high-speed opening condition one trigger, then this time uses the low-speed opening condition three trigger; if the last time is the high-speed opening condition two trigger, then this time uses the low-speed opening condition four trigger; if the last time is the low-speed opening condition three trigger, then this time uses the high-speed opening condition one trigger; if the last time is the low-speed opening condition four trigger, then this time uses the high-speed opening condition two trigger.

[0025] S24, compare the difference between the product of the fan rated power corresponding to the fan operation gear and the fan running time this time and the product of the fan rated power corresponding to the fan operation gear and the fan running time under the same condition last time, and compare the difference in battery SOC when the fan is closed under the same condition twice;

[0026] S25, according to the fan operation condition, the difference between the product of the fan rated power corresponding to the fan operation gear and the fan running time, and the difference in battery SOC when the fan is closed under the same condition twice, execute the corresponding cooling fan control parameter update strategy.

[0027] Specifically as follows:

[0028] 1) When the fan operation condition under the same condition last time is the high-speed opening condition one, and the fan operation condition this time is the low-speed opening condition three:

[0029] 1.1) If the difference in battery SOC when the fan is closed is less than the preset difference V1, and the difference between the product of the fan rated power and the fan running time is greater than the preset difference W1, then increase the preset value A in the cooling fan step control method under the same condition next time by 10%, and reduce the preset value C by 5%, and store the updated preset value A and preset value C in the power-off state;

[0030] 1.2) If the time difference between the first time when the cooling liquid water temperature reaches the preset water temperature and the time when the fan is closed under the same condition twice is greater than the preset value M1, then reduce the preset time T1 in the cooling fan step control method under the same condition next time by 5%, and reduce the preset time T3 by 2%, and store the updated preset time T1 and preset time T3 in the power-off state;

[0031] 1.3) If the time difference between the first time when the cooling liquid water temperature reaches the preset water temperature and the time when the fan is closed under the same condition twice is not greater than the preset value M1, and the number of times when the cooling liquid water temperature is greater than the preset water temperature when the fan is closed exceeds the preset value CNT, then increase the preset time T1 in the cooling fan step control method under the same condition next time by 3%, and increase the preset time T3 by 2%, and store the updated preset time T1 and preset time T3 in the power-off state.

[0032] 2) When the last time the same working condition of the fan operating condition is high-speed open condition two, this time the fan operating condition is low-speed open condition four:

[0033] 2.1) If the battery SOC difference when the fan is closed is less than the preset difference V2, and the product difference of the fan rated power and the fan running time is greater than the preset difference W2 (W2 is less than W1), then the preset value B in the cooling fan step control method under the same working condition next time is increased by 5%, the preset value D is reduced by 2%, and the updated preset value B and the preset value D are stored;

[0034] 2.2) If the time difference between the first time when the cooling liquid water temperature reaches the preset water temperature and the time when the fan is closed under the same working condition twice is greater than the preset value M2 (M2 is less than M1), then the preset time T2 in the cooling fan step control method under the same working condition next time is reduced by 5%, the preset time T4 is reduced by 4%, and the updated preset time T2 and the preset time T4 are stored;

[0035] 2.3) If the time difference between the first time when the cooling liquid water temperature reaches the preset water temperature and the time when the fan is closed under the same working condition twice is not greater than the preset value M2, and the number of times when the cooling liquid water temperature is greater than the preset water temperature when the fan is closed exceeds the preset value CNT, then the preset time T2 in the cooling fan step control method under the same working condition next time is increased by 2%, the preset time T4 is increased by 1%, and the updated preset time T2 and the preset time T4 are stored.

[0036] 3) When the last time the same working condition of the fan operating condition is low-speed open condition three, this time the fan operating condition is high-speed open condition one:

[0037] 3.1) If the battery SOC difference when the fan is closed is less than the preset difference V1, and the product difference of the fan rated power and the fan running time is greater than the preset difference W1, then the preset value A in the cooling fan step control method under the same working condition next time is increased by 2%, the preset value C is reduced by 1%, and the updated preset value A and the preset value C are stored;

[0038] 3.2) If the time difference between the first time when the cooling liquid water temperature reaches the preset water temperature and the time when the fan is closed under the same working condition twice is greater than the preset value M1, then the preset time T1 in the cooling fan step control method under the same working condition next time is reduced by 4%, the preset time T3 is reduced by 2%, and the updated preset time T1 and the preset time T3 are stored;

[0039] 3.3) If the time difference between the first time when the coolant water temperature reaches the preset water temperature and the time when the fan is turned off is greater than the preset value M1, and the number of times when the coolant water temperature is greater than the preset water temperature when the fan is turned off exceeds the preset value CNT, then the preset time T1 in the next cooling fan step control method under the same working condition is increased by 2%, the preset time T3 is increased by 1%, and the updated preset time T1 and the preset time T3 are stored.

[0040] 4) When the fan operating condition in the last same working condition is high-speed opening condition two, and the fan operating condition in this time is low-speed opening condition four:

[0041] 4.1) If the difference in the battery SOC when the fan is turned off is less than the preset difference V2, and the product difference of the fan rated power and the fan operating time is greater than the preset difference W2, then the preset value B in the next cooling fan step control method under the same working condition is reduced by 2%, the preset value D is increased by 1%, and the updated preset value B and the preset value D are stored.

[0042] 4.2) If the time difference between the first time when the coolant water temperature reaches the preset water temperature and the time when the fan is turned off is greater than the preset value M2, then the preset time T2 and the preset time T4 in the next cooling fan step control method under the same working condition are increased by 0.5%, and the updated preset time T2 and the preset time T4 are stored.

[0043] II. An engine cooling fan control system

[0044] Based on the same inventive concept, the application also provides an engine cooling fan control system for implementing the control method as described above, mainly comprising: an engine outlet water temperature sensor, an atmospheric temperature sensor (or atmospheric temperature signal), a vehicle speed sensor (or vehicle speed signal), a water pump, a thermal management module (including an electronic thermostat), a cooling fan, and an engine cooling controller.

[0045] 1) An engine outlet water temperature sensor for detecting the temperature of the cooling water at the engine outlet, referred to as a water temperature sensor, for detecting the actual water temperature of the engine;

[0046] 2) An atmospheric temperature sensor or atmospheric temperature signal, the engine cooling controller is hard-wired to the atmospheric temperature sensor, or receives the atmospheric temperature signal through network CAN communication, etc.;

[0047] 3) A vehicle speed sensor or vehicle speed signal, the engine cooling controller is hard-wired to the vehicle speed sensor, or receives the vehicle speed signal through network CAN communication, etc.;

[0048] 4) A water pump for driving the circulation of cooling water;

[0049] 5) cooling fan, provided with two gears, i.e. two rotating speeds, low speed and high speed, two fixed powers for cooling the cooling water flowing through the radiator.

[0050] 6) engine cooling controller, used for receiving and processing the data sent by the engine outlet water temperature sensor, the atmospheric temperature sensor, the vehicle speed sensor and the battery SOC, and performing corresponding control on the engine cooling fan according to the control method as described above.

[0051] Three, a manual and automatic vehicle

[0052] Based on the same inventive concept, the application also provides a manual and automatic vehicle, which is provided with the engine cooling fan control system as described above.

[0053] Compared with the prior art, the application has the following main advantages:

[0054] 1. The application provides a control method and system for a cooling fan after engine shutdown of a vehicle, which controls the opening gear and opening time of the cooling fan based on the highest water temperature after shutdown, and dynamically and self-learns and updates the fan control parameters, and then controls the opening gear and opening time of the cooling fan based on the updated fan control parameters, so that the service life of the engine is improved while the overall energy consumption of the system is reduced.

[0055] 2. The application controls the high speed and low speed operation of the cooling fan by different shutdown water temperature grading, so that the electrical load can be reasonably distributed under the premise of fully considering the service life of the engine, and the energy consumption required for the operation of the cooling fan is effectively reduced.

[0056] 3. The application provides a self-learning method for fan control parameters, which can dynamically and intelligently control the cooling fan according to the real-time performance of the cooling system energy consumption after engine shutdown, and thus real-time control the optimal energy consumption of the engine in different life cycles. BRIEF DESCRIPTION OF DRAWINGS

[0057] Figure 1 It is a whole flow chart of the engine cooling fan control method in the embodiment of the application.

[0058] Figure 2 It is a flow chart of the cooling fan grading control method in the embodiment of the application.

[0059] Figure 3 It is a flow chart of the cooling fan control parameter self-learning and updating method in the embodiment of the application.

[0060] Figure 4 It is a schematic diagram of the engine cooling fan control system in the embodiment of the application. DETAILED DESCRIPTION

[0061] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0062] It should be noted that, according to the needs of implementation, each step / component described in the present application can be split into more steps / components, or two or more steps / components or part of the operation of the steps / components can be combined into a new step / component to achieve the purpose of the present application.

[0063] In one embodiment, a control method for a cooling fan after engine shutdown is provided, which ensures to improve the service life of the engine under the premise of reducing the overall electrical load energy consumption as much as possible.

[0064] As shown in Figures 1 to 3 , it mainly includes two parts, the first part is to control the opening gear (high speed and low speed) and the opening time of the cooling fan based on the highest water temperature after shutdown, and the second part is to consider the cooling fan control parameter self-learning based on the angle of reducing the electrical load energy consumption.

[0065] Step 1: Control the opening gear (high speed and low speed) and the opening time of the cooling fan based on the highest water temperature after shutdown.

[0066] Record and update the highest water temperature (referred to as the highest water temperature) after engine shutdown in real time, and divide the highest water temperature into multiple intervals:

[0067] 1) When the current highest water temperature is greater than the preset value A, the high-speed gear of the fan is started, and the opening time is the preset time T1; the working condition under this condition is recorded as high-speed fan opening condition one.

[0068] 2) When the current highest water temperature is not greater than A and is greater than the preset value B, the high-speed gear of the fan is started, and the opening time is the preset time T2; the working condition under this condition is recorded as high-speed fan opening condition two.

[0069] 3) When the current highest water temperature is not greater than B and is greater than the preset value C, the low-speed gear of the fan is started, and the opening time is the preset time T3; the working condition under this condition is recorded as low-speed fan opening condition three.

[0070] 4) When the current highest water temperature is not greater than C and is greater than the preset value D, the low-speed gear of the fan is started, and the opening time is the preset time T4; the working condition under this condition is recorded as low-speed fan opening condition four.

[0071] The preset values are A>B>C>D, the preset value A is 116℃, the preset value B is 114℃, the preset value C is 112℃, and the preset value D is 110℃, and the preset value is dynamically updated according to the electrical load energy consumption.

[0072] The preset times are T1>T2>T3>T4, T1, T2, T3 and T4 depend on the atmospheric temperature and atmospheric pressure, the higher the atmospheric temperature and the smaller the atmospheric pressure, the longer the water temperature heat dissipation capacity, and therefore the longer the fan opening time. The preset time calibration in the present example is shown in Tables 1-4 below, and the preset time value is dynamically updated according to the electrical load energy consumption.

[0073] Table 1

[0074]

[0075] Table 2

[0076]

[0077] Table 3

[0078]

[0079] Table 4

[0080]

[0081] The priority of the above four conditions is lower and lower, once the higher priority condition is met, the corresponding fan action under the condition that the fan opening gear and opening time are satisfied is restarted. That is, once condition 1 is not met, but condition 2 is met, regardless of the previous fan gear, the high-speed gear of the fan is started, and the opening time is restarted for the preset time T2.

[0082] As can be seen from the above table, before the engine fan is stopped (the fan stop means that the fan is not started), the water temperature will be less than the preset value D.

[0083] Secondly, the control parameter self-learning is performed based on the consideration of reducing the electrical load energy consumption.

[0084] Record the fan control condition after each shutdown, if the mileage of the parameter is not updated more than the preset value (2,000 km in this example, the mileage is recalculated after any parameter is updated, if the mileage does not exceed the preset mileage, the parameter self-learning update is not performed. The performance of engine parts is updated slowly when the mileage is low, and the parameter self-learning does not need to be performed too frequently), record the condition after each shutdown without other electrical load (only the cooling fan is turned on, the air conditioner and the headlight are not turned on, if there is other electrical load in addition to the cooling fan, the parameter self-learning update is not performed), the atmospheric temperature after shutdown, the atmospheric temperature after shutdown, the highest water temperature after shutdown, the fan speed after shutdown (high speed fan or low speed fan), the fan opening time after shutdown, the water temperature after the fan is turned off, the difference between the battery SOC at the time of engine shutdown and the battery SOC at the time of fan shutdown (referred to as the difference between the battery SOC at the time of shutdown and the time of fan shutdown), the time difference between the time when the water temperature first approaches the preset value E (the preset value E is equal to the atmospheric temperature plus an upward deviation F, F depends on the atmospheric temperature) and the time when the fan is turned off (if the water temperature does not first approach the preset value E at the time when the fan is turned off, the time difference is 0). When the atmospheric temperature after shutdown, the atmospheric pressure after shutdown, the highest water temperature after shutdown, and the fan speed after shutdown (high speed fan or low speed fan) are the same, it is considered to be the same working condition.

[0085] When the same working condition is encountered again next time, the fan speed is changed (i.e. if the last time is high speed fan opening working condition one, this time low speed fan opening working condition three is adopted; if the last time is high speed fan opening working condition two, this time low speed fan opening working condition four is adopted; if the last time is low speed fan opening working condition three, this time high speed fan opening working condition one is adopted; if the last time is low speed fan opening working condition four, this time high speed fan opening working condition two is adopted), the water temperature is controlled to decrease to the same water temperature after the fan is turned off in the last same working condition, then the fan is controlled to stop running, the fan opening time is recorded, and the difference between the battery SOC at the time of shutdown and the time of fan shutdown is recorded.

[0086] The product of the fan rated power corresponding to the fan speed of the last same working condition (provided by the fan supplier, in this example, the fan rated power under high speed operation is fixed, the fan rated power under low speed operation is fixed, and the two are not the same, the fan rated power under high speed operation is higher than the fan rated power under low speed operation) and the fan opening time is compared with the product of the fan rated power corresponding to the fan speed of this time and the fan opening time, and the difference between the battery SOC at the time of shutdown and the time of fan shutdown under the same working condition is compared.

[0087] 1) If the fan speed of the last same working condition is high speed opening working condition one, this time the same working condition is low speed fan opening working condition three:

[0088] 1.1) If the SOC difference under the same working condition is small (the judgment standard of the SOC difference is that the absolute value of the difference between the SOC difference under the same working condition twice is not more than 2% of the SOC difference under the same working condition last time), but the fan power and fan opening time product difference is reduced more (the difference between the fan power and fan opening time product under the same working condition last time and the fan power and fan opening time product under the same working condition this time is divided by the fan power and fan opening time product under the same working condition this time, and it is considered that the fan power and fan opening time product difference is reduced more if the result is larger), and the result exceeds the preset value W1 (5% in this example), then the preset value A under the same working condition after the engine stops again is increased (the preset value A in this example is increased to 1.1 times of the original preset value A. If the preset value A is updated before, the original preset value A is the preset value stored after the last update. If the preset value A is not updated before, the original preset value A refers to the value set before, which is 116°C in this example), and the preset value C is reduced (the preset value C in this example is reduced to 0.95 times of the original preset value C. If the preset value C is updated before, the original preset value C is the preset value stored after the last update. If the preset value C is not updated before, the original preset value C refers to the value set before, which is 112°C in this example), and the preset value A and the preset value C under the same working condition are updated and stored.

[0089] 1.2) If the time difference between the time when the water temperature approaches the preset value E for the first time and the time when the fan is turned off under the same working condition twice is greater than the preset value M1 (more than 10s in this example), then the preset time T1 and T3 under the same working condition after the engine stops again is reduced (the preset time T1 in this example is reduced to 0.95 times of the original preset time T1, and the preset time T3 is reduced to 0.98 times of the original preset time T3. Similarly, the original preset time T1 and the original preset time T3 are defined as the original preset value A), and the preset time T1 and T3 under the same working condition are updated and stored.

[0090] 1.3) If the water temperature at the fan-off time is greater than the preset value E, and the number of occurrences (the number of occurrences is calculated as follows: when condition 1 is met, and condition 1.2 is not met, and the water temperature at the fan-off time is greater than the preset value E, the number of occurrences is added once. When the next condition 1 is met, and condition 1.2 is not met, and the water temperature at the fan-off time is greater than the preset value E, the number of occurrences is added again. Otherwise, the number of occurrences remains unchanged. In particular, if condition 1 is met, and condition 1.2 is met, the number of occurrences is cleared) exceeds the preset value CNT (in this example, 30), then the preset times T1 and T3 under the same working condition are increased after the engine is stopped again (in this example, the preset time T1 is increased to 1.03 times the original preset time T1, and the preset time T3 is increased to 1.02 times the original preset time T3. Similarly, the original preset time T1 and the original preset time T3 are defined as the original preset value A), and the updated values of the preset times T1 and T3 under the same working condition are stored.

[0091] 2) If the fan speed in the same working condition last time is high-speed open working condition two, and this time is low-speed fan open working condition four:

[0092] 2.1) If the SOC difference under the same working condition is small, but the fan power and fan opening time product difference decreases more, which exceeds the preset value W2 (W2 does not exceed W1, and in this example, W2 is 3%), then the preset value B under the same working condition is increased (in this example, the preset value B is increased to 1.05 times the original preset value B. If the preset value B has been updated before, the original preset value B is the preset value stored after the last update. If the preset value B has not been updated before, the original preset value B refers to the value set before, which is 114°C in this example) and the preset value D is decreased (in this example, the preset value D is decreased to 0.98 times the original preset value D. Similarly, the original preset value D is defined as the original preset value A) after the engine is stopped again, and the updated values of the preset value B and the preset value D under the same working condition are stored.

[0093] 2.2) If the time difference between the time when the water temperature first approaches the preset value E and the fan-off time under the same working condition both exceeds the preset value M2 (in this example, more than 8s), then the preset times T2 and T4 under the same working condition are decreased (in this example, the preset time T2 is decreased to 0.95 times the original preset time T2, and the preset time T4 is decreased to 0.96 times the original preset time T4. Similarly, the original preset time T2 and the original preset time T4 are defined as the original preset value A) after the engine is stopped again, and the updated values of the preset times T2 and T4 under the same working condition are stored.

[0094] 2.3) If the water temperature at the fan-off time is greater than the preset value E, and the number of occurrences (the number of occurrences is calculated as follows: when condition 2 is met, and condition 2.2 is not met, and the water temperature at the fan-off time is greater than the preset value E, the number of occurrences is added once. When the next time condition 2 is met, and condition 2.2 is not met, and the water temperature at the fan-off time is greater than the preset value E is met, the number of occurrences is added again. Otherwise, the number of occurrences remains unchanged. In particular, if condition 2 is met, and condition 2.2 is met, the number of occurrences is cleared) exceeds the preset value CNT, then the preset time T2 and T4 under the same working condition are increased after the engine is stopped again (in this example, the preset time T2 is increased to 1.02 times the original preset time T2, and the preset time T4 is increased to 1.01 times the original preset time T4. Similarly, the original preset time T2 and the preset time T4 are defined as the original preset value A), and the updated values of the preset time T2 and T4 under the same working condition are stored.

[0095] 3) If the fan speed in the same working condition last time is low-speed fan open working condition three, and this time is high-speed open working condition one:

[0096] 3.1) If the SOC difference between the two same working conditions is small, but the fan power and fan opening time product difference decreases more, exceeding the preset value W1, then the preset value A under the same working condition is reduced after the engine is stopped again (in this example, the preset value A is reduced to 0.98 times the original preset value A. If the preset value A has been updated before, the original preset value A is the preset value after the last update; if the preset value A has not been updated before, the original preset value A refers to the value set before, which is 116°C in this example), and the preset value C is increased (in this example, the preset value C is reduced to 0.99 times the original preset value A. If the preset value C has been updated before, the original preset value C is the preset value after the last update; if the preset value C has not been updated before, the original preset value C refers to the value set before, which is 112°C in this example), and the updated values of the preset values A and C under the same working condition are stored;

[0097] 3.2) If the time difference between the water temperature and the preset value E first close time and the fan-off time is greater than the preset value M1, then the preset time T1 and T3 under the same working condition are reduced after the engine is stopped again (in this example, the preset time T1 is reduced to 0.96 times the original preset time T1, and the preset time T3 is reduced to 0.98 times the original preset time T3. Similarly, the original preset time T1 and the preset time T3 are defined as the original preset value A), and the updated values of the preset time T1 and T3 under the same working condition are stored

[0098] 3.3) If the water temperature at the time of fan off is greater than the preset value E, and the number of times (the calculation method is as follows: when condition 3 is met, and condition 3.2 is not met, and the water temperature at the time of fan off is greater than the preset value E, the number of times is added by one. When the next time condition 3 is met, and condition 3.2 is not met, and the water temperature at the time of fan off is greater than the preset value E is met, the number of times is added again. Otherwise, the number of times remains unchanged. In particular, if condition 3 is met, and condition 3.2 is met, the number of times is cleared) exceeds the preset value CNT, then the preset time T1 and T3 under the same working condition are increased after the engine is stopped again (in this example, the preset time T1 is increased to 1.02 times the original preset time T1, and the preset time T3 is increased to 1.01 times the original preset time T3, and the original preset time T1 and the original preset time T3 are defined as the original preset value A), and the updated values of the preset time T1 and T3 under the same working condition are stored.

[0099] 4) If the last time the fan gear was low-speed fan opening working condition four, this time is high-speed opening working condition two:

[0100] 4.1) If the difference between the two SOCs is small, but the difference between the product of the fan power and the fan opening time is reduced more, which exceeds the preset value W2, then the preset value B under the same working condition is reduced (in this example, the preset value B is reduced to 0.98 times the original preset value B. If the preset value B has been updated before, the original preset value B is the preset value stored after the last update; if the preset value B has not been updated before, the original preset value B refers to the value set before, which is 114°C in this example) and the preset value D is increased (in this example, the preset value D is increased to 1.01 times the original preset value D, and the original preset value D is defined as the original preset value A) after the engine is stopped again, and the updated values of the preset value B and the preset value D under the same working condition are stored;

[0101] 4.2) If the time difference between the time when the water temperature is close to the preset value E for the first time and the time when the fan is off is greater than the preset value M2 both times, then the preset time T2 and T4 under the same working condition are reduced (in this example, the preset time T2 is increased to 1.005 times the original preset time T2, and the preset time T4 is increased to 1.005 times the original preset time T4, and the original preset time T2 and the original preset time T4 are defined as the original preset value A) after the engine is stopped again, and the updated values of the preset time T2 and T4 under the same working condition are stored.

[0102] After all the above parameters (preset values and preset times) are updated, the updated values are used after the engine is stopped again, and finally ensure that in the fan control after the same engine stop:

[0103] The preset value A > B > C > D;

[0104] Pre-set time T1>T2>T3>T4;

[0105] If the updated B is greater than the updated A in the same engine shutdown working condition, the final control B is equal to A, and other parameters are similar.

[0106] Embodiment two, based on the same inventive concept, the embodiment also provides an engine cooling fan control system for realizing the control method as described above, such as Figure 4 As shown, mainly includes: engine outlet water temperature sensor, atmospheric temperature sensor (or atmospheric temperature signal), vehicle speed sensor (or vehicle speed signal), water pump, thermal management module (including electronic thermostat), cooling fan and engine cooling controller.

[0107] 1) Engine outlet water temperature sensor for detecting engine outlet cooling water temperature, referred to as water temperature sensor, detecting the actual engine water temperature;

[0108] 2) Atmospheric temperature sensor or atmospheric temperature signal, the engine cooling controller is hard-wired connected to the atmospheric temperature sensor, or receives the atmospheric temperature signal through the network CAN communication;

[0109] 3) Vehicle speed sensor or vehicle speed signal, the engine cooling controller is hard-wired connected to the vehicle speed sensor, or receives the vehicle speed signal through the network CAN communication;

[0110] 4) Water pump for driving cooling water circulation;

[0111] 5) Cooling fan, provided with two gears, that is, two speeds, low speed and high speed two fixed power, for cooling the cooling water flowing through the radiator.

[0112] 6) Engine cooling controller for receiving and processing the data sent by the engine outlet water temperature sensor, atmospheric temperature sensor, vehicle speed sensor and battery SOC, and performing corresponding control on the engine cooling fan according to the control method as described above.

[0113] Embodiment three, based on the same inventive concept, the embodiment also provides a manual-automatic vehicle, which is installed with the engine cooling fan control system as described above.

[0114] Further, the parts not described in detail in the present application are the same as or realized by the prior art.

[0115] In summary:

[0116] 1. The application provides a kind of control method and system of cooling fan after vehicle engine stops, based on the highest water temperature of shutdown, the opening gear and opening time of cooling fan are controlled in stages, and the fan control parameter is dynamically self-learned and updated, then the opening gear and opening time of cooling fan are controlled based on the updated fan control parameter, which can improve the service life of engine while reducing the overall energy consumption of system;

[0117] 2. The application controls the high-speed and low-speed operation of cooling fan by different shutdown water temperature in stages, which can reasonably allocate power load and effectively reduce the energy consumption required for cooling fan to work under the premise of fully considering the service life of engine;

[0118] 3. The application provides a self-learning method of fan control parameter, which can dynamically and intelligently control cooling fan according to the real-time performance of cooling system energy consumption after engine stops, and then real-time control the optimal energy consumption of engine in different life cycle.

[0119] Those skilled in the art will readily understand that the above description is only a preferred embodiment of the present application, and is not intended to limit the present application, and any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A control method of a cooling fan after engine stop of a vehicle, characterized by, The application relates to a cooling fan step control method based on the highest water temperature of shutdown and a cooling fan control parameter self-learning updating method. The cooling fan step control method based on the highest water temperature of shutdown comprises the following strategies: Real-time recording and updating of the highest water temperature of the cooling liquid after engine shutdown, and division of the highest water temperature into multiple intervals; Real-time acquisition of the current atmospheric temperature and atmospheric pressure, and division of the atmospheric temperature and atmospheric pressure into multiple intervals; Determination of the initial running gear of the cooling fan according to the interval of the highest water temperature, and determination of the initial running time of the cooling fan according to the interval of the atmospheric temperature and atmospheric pressure; Step control of the cooling fan based on the initial running gear and initial running time; The cooling fan control parameter self-learning updating method comprises the following strategies: Recording of the control parameter value of the cooling fan after each engine shutdown, judgment of whether the vehicle mileage under the condition that the control parameter is not updated exceeds a preset mileage, if yes, recording of the engine cooling system working condition under the condition that only the cooling fan works after engine shutdown and system data under the condition; When the same system working condition is encountered again, switching of the current fan running working condition, and control of the fan to stop running when the cooling liquid water temperature reaches the cooling liquid water temperature when the fan is turned off under the last same working condition, recording of the current fan running time and the difference between the battery SOC when the engine is shutdown and when the fan is turned off; Comparison of the difference between the product of the fan rated power corresponding to the current fan running gear and the fan running time and the product of the fan rated power corresponding to the fan running gear under the last same working condition and the difference between the battery SOC when the fan is turned off under the two same working conditions; According to the fan running working condition, the difference between the product of the fan rated power corresponding to the fan running gear and the fan running time and the difference between the battery SOC when the fan is turned off under the two same working conditions, corresponding cooling fan control parameter updating strategies are executed.

2. A control method of a cooling fan after engine stop of a vehicle according to claim 1, characterized by, The step control of the cooling fan is specifically as follows: When the current highest water temperature is greater than a preset value A, the high-speed gear of the fan is started, and the starting time is a preset time T1; the working condition under the condition is recorded as high-speed starting condition one; When the current highest water temperature is not greater than the preset value A and is greater than a preset value B, the high-speed gear of the fan is started, and the starting time is a preset time T2; the working condition under the condition is recorded as high-speed starting condition two; When the current highest water temperature is not greater than the preset value B and is greater than a preset value C, the low-speed gear of the fan is started, and the starting time is a preset time T3; the working condition under the condition is recorded as low-speed starting condition three; When the current highest water temperature is not greater than the preset value C and is greater than a preset value D, the low-speed gear of the fan is started, and the starting time is a preset time T4; the working condition under the condition is recorded as low-speed starting condition four.

3. The control method of a cooling fan after engine stop of a vehicle according to claim 1, characterized by, The system working condition comprises the atmospheric temperature, the atmospheric temperature, the highest water temperature of the cooling liquid and the fan running gear; The system data comprises the fan running time, the cooling liquid water temperature after the fan is turned off, the difference between the battery SOC when the engine is shutdown and when the fan is turned off, and the time difference between the first time when the cooling liquid water temperature reaches a preset water temperature and when the fan is turned off.

4. The control method of a cooling fan after engine stop of a vehicle according to claim 2, characterized by, The switching this time fan operating condition is specifically as follows: If the last time is high-speed opening condition one trigger, this time uses low-speed opening condition three trigger; if the last time is high-speed opening condition two trigger, this time uses low-speed opening condition four trigger; if the last time is low-speed opening condition three trigger, this time uses high-speed opening condition one trigger; if the last time is low-speed opening condition four trigger, this time uses high-speed opening condition two trigger.

5. A control method of a cooling fan after engine stop of a vehicle according to claim 3, characterized by, The corresponding cooling fan control parameter updating strategy is executed, and is specifically as follows: If the battery SOC difference when the fan is closed is less than a preset difference V, and the product difference of the fan rated power and the fan running time is greater than a preset difference W, then the preset values A and B in the next time cooling fan step control method under the same condition are increased by a preset proportion, the preset values C and D are reduced by a preset proportion, and the updated preset values A, B, C and D are stored by power-off; If the time difference between the first time when the cooling liquid water temperature reaches the preset water temperature and the time when the fan is closed under the same condition twice is greater than a preset value M, then the preset times T1-T4 in the next time cooling fan step control method under the same condition are reduced by a preset proportion, and the updated preset times T1-T4 are stored by power-off.

6. A control method of a cooling fan after engine stop of a vehicle according to claim 5, characterized by, If the time difference between the first time when the cooling liquid water temperature reaches the preset water temperature and the time when the fan is closed under the same condition twice is not greater than a preset value M, and the number of times that the cooling liquid water temperature is greater than the preset water temperature when the fan is closed exceeds a preset value CNT, then the preset times T1-T4 in the next time cooling fan step control method under the same condition are increased by a preset proportion, and the updated preset times T1-T4 are stored by power-off.

7. An engine cooling fan control system for implementing the control method according to any one of claims 1 to 6, characterized by It comprises: An engine outlet water temperature sensor for detecting engine outlet cooling water temperature; An atmospheric temperature sensor for obtaining an atmospheric temperature signal; A vehicle speed sensor for obtaining a vehicle speed signal; A water pump for driving cooling water circulation; A cooling fan with low-speed and high-speed power modes for cooling cooling water flowing through the radiator; An engine cooling controller for receiving and processing data sent by the engine outlet water temperature sensor, the atmospheric temperature sensor, the vehicle speed sensor and the battery SOC, and performing corresponding control on the engine cooling fan according to the control method of any one of claims 1 to 6.

8. A non-transitory readable storage medium having stored thereon a program, the program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 7. The program is executed by the engine cooling fan control system to realize the control method of any one of claims 1 to 6.

9. A hybrid vehicle characterized by comprising: The engine cooling fan control system of claim 7. The engine cooling fan control system of claim 7.

Images