A control method for a vehicle radiator fan

Abstract

The present invention discloses a control method for a vehicle radiator fan, which belongs to the technical field of engine control. The present invention considers the following aspects: the reason for fan control based on water temperature is that the fan needs to be turned on when the water temperature is too high to avoid poor vehicle power, economy and emissions, and to avoid the occurrence of knock; the reason for fan control based on intake air temperature and vehicle speed is that when the intake air temperature is too high and the vehicle speed is too low, the risk of engine knock will increase; the purpose of dynamic control and intelligent control optimization based on the real-time performance of the cooling system is to perform dynamic control optimization in real time because the engine operating conditions are transient and complex, and to improve control optimization for cooling system aging to provide control accuracy.

Description

Technical Field

[0001] The present invention belongs to the technical field of engine control, and more particularly, relates to a control method for a vehicle radiator fan. Background Art

[0002] During normal vehicle operation, the engine coolant temperature must be maintained within an appropriate range to optimize power, economy, and emissions. When the engine coolant temperature is too high, active engine cooling is required. This is achieved by controlling the electronically controlled thermal management module and fan to cool the engine while it is operating.

[0003] Patent application CN114017174A discloses a method and device for controlling a fan in an engine cooling system. The method controls the fan based on a water temperature difference. However, this approach fails to consider dynamic control of the cooling system's real-time performance and fails to recognize potential changes in control parameters due to complex engine operating conditions and component aging, leading to decreasing cooling system control accuracy.

[0004] Referring to the patent application with publication number CN111350580A, an engine cooling system and an engine cooling control method directly compare the target temperature with the actual temperature. Based on the magnitude of the target temperature and the actual temperature, only two operating conditions are divided: when the actual temperature reaches a first target preset temperature and is greater than a second target preset temperature, the control module controls the electronic thermostat to open a first water path connected to the heat dissipation device until the actual temperature drops to the second target preset temperature; when the actual temperature is less than the second target preset temperature, the control module controls the electronic thermostat to close until the actual temperature reaches the first target preset temperature. However, the entire cooling control system is also equipped with a heater and an oil device, but does not collect and use vehicle speed signals, and does not consider dynamic control of the real-time performance of the cooling system. It does not recognize the problem of changes in control parameters caused by the complex operating conditions of the engine and the aging of components, which leads to the problem of increasingly poor control accuracy of the cooling system. Summary of the Invention

[0005] In response to the above defects or improvement needs of the prior art, the present invention proposes a control method for a vehicle radiator fan. Since the radiator fan speed is not steplessly controllable, the water temperature cannot be accurately controlled. The problem of fluctuating water temperature is solved by optimizing the control method.

[0006] To achieve the above object, the present invention provides a method for controlling a vehicle radiator fan, comprising:

[0007] Filter the actual water temperature and vehicle speed;

[0008] Controlling the fan based on the actual filtered water temperature, wherein the controlling the fan based on the actual filtered water temperature includes turning on a high-speed fan based on the actual filtered water temperature and turning on a low-speed fan based on the actual filtered water temperature;

[0009] Controlling the fan based on the intake air temperature and the filtered vehicle speed, wherein the control of the fan by the intake air temperature and the filtered vehicle speed includes turning on the high-speed fan based on the intake air temperature and the filtered vehicle speed and turning on the low-speed fan based on the intake air temperature and the filtered vehicle speed;

[0010] Based on the real-time performance of the cooling system, dynamic control and intelligent control optimization are performed on the fan control based on the filtered actual water temperature and the fan control based on the intake air temperature and filtered vehicle speed.

[0011] In some optional embodiments, T CoolantAct (N) = k1 × [T CoolantActRaw -T CoolantAct (N-1)]+T CoolantAct (N-1) Filter the actual water temperature, where N = 1, 2, 3..., T CoolantAct (N-1) is the actual water temperature after filtering at time N-1; T CoolantAct (N) is the actual water temperature after filtering at time N; the time difference between time N-1 and time N is the fixed update period ΔT; T CoolantActRaw is the original actual water temperature collected by the water temperature sensor at time N; k1 is the water temperature filter coefficient;

[0012] From v(N)=k2×[v Raw -v(N-1)]+v(N-1) is used to filter the vehicle speed, where N=1, 2, 3..., v(N-1) is the filtered vehicle speed at time N-1; v(N) is the filtered vehicle speed at time N; the time difference between time N-1 and time N is a fixed update period ΔT; v Raw is the original unprocessed vehicle speed signal at time N; k2 is the vehicle speed filter coefficient.

[0013] In some optional embodiments, the high-speed fan is turned on based on the filtered actual water temperature, comprising:

[0014] If the difference between the actual water temperature after filtering and the target water temperature is less than the preset value A1, where the preset value A1 is equal to the preset value B1 minus the margin C1, and the margin C1 depends on the atmospheric temperature, the high-speed fan on timer is reset to 0; if the difference between the actual water temperature after filtering and the target water temperature exceeds the preset value B1, where the preset value B1 depends on the target water temperature, the time when the difference between the actual water temperature after filtering and the target water temperature exceeds the preset value B1 is accumulated, and the accumulated time is used as the time recorded by the high-speed fan on timer; if the difference between the actual water temperature after filtering and the target water temperature does not exceed the preset value B1 and is not less than the preset value A1, the high-speed fan on timer remains unchanged; if the high-speed fan on timer exceeds the preset time T1, the high-speed fan on condition one is met, otherwise the high-speed fan on condition one is not met;

[0015] If the actual water temperature after filtering exceeds the preset value D1, where the preset value D1 depends on the target water temperature, then the second condition for turning on the high-speed fan is met. If the actual water temperature after filtering does not exceed the preset value E1, where the preset value E1 is equal to the preset value D1 minus the margin F1, then the second condition for turning on the high-speed fan is not met.

[0016] In some optional embodiments, the low-speed fan start-up based on the filtered actual water temperature includes:

[0017] If the difference between the actual water temperature after filtering and the target water temperature is less than the preset value A2, where the preset value A2 is equal to the preset value B2 minus the margin C2, and the margin C2 depends on the atmospheric temperature, the low-speed fan on timer is reset to 0; if the difference between the actual water temperature after filtering and the target water temperature exceeds the preset value B2, where the preset value B2 depends on the target water temperature, the time when the difference between the actual water temperature after filtering and the target water temperature exceeds the preset value B2 is accumulated, and the accumulated time is used as the time recorded by the low-speed fan on timer; if the difference between the actual water temperature after filtering and the target water temperature does not exceed the preset value B2 and is not less than the preset value A2, the low-speed fan on timer remains unchanged; if the low-speed fan on timer exceeds the preset time T2, the low-speed fan on condition one is met, otherwise the low-speed fan on condition one is not met;

[0018] If the actual water temperature after filtering exceeds the preset value D2, where the preset value D2 depends on the target water temperature, then the second condition for starting the low-speed fan is met; if the actual water temperature after filtering does not exceed the preset value E2, where the preset value E2 is equal to the preset value D2 minus the margin F2, then the second condition for starting the low-speed fan is not met.

[0019] In some optional implementations, the high-speed fan is turned on based on the intake air temperature and the filtered vehicle speed, including:

[0020] If the actual intake air temperature exceeds a preset value D3, where the preset value D3 depends on the filtered vehicle speed, then the high-speed fan activation condition three is met; if the actual intake air temperature does not exceed a preset value E3, where the preset value E3 is equal to the preset value D3 minus the margin F3, then the high-speed fan activation condition three is not met;

[0021] The low-speed fan start based on the intake air temperature and the filtered vehicle speed includes:

[0022] If the actual intake air temperature exceeds the preset value D4, where the preset value D4 depends on the filtered vehicle speed, the low-speed fan start-up condition three is met; if the actual intake air temperature does not exceed the preset value E4, where the preset value E4 is equal to the preset value D4 minus the margin F4, the low-speed fan start-up condition three is not met.

[0023] In some optional implementation schemes, if any one of the high-speed fan triggering conditions is met, that is, if one of the high-speed fan start-up condition 1, the high-speed fan start-up condition 2, or the high-speed fan start-up condition 3 is met, then the high-speed fan start-up condition is met. After the high-speed fan start-up condition is met, the high-speed fan is triggered to turn on, and the shortest turn-on time shall not be less than the preset time T3;

[0024] If any one of the conditions for triggering the low-speed fan is met, that is, one of the low-speed fan start-up condition one, the low-speed fan start-up condition two or the low-speed fan start-up condition three is met, then the low-speed fan start-up condition is met. After the low-speed fan start-up condition is met, the low-speed fan is triggered to turn on, and the shortest start-up time shall not be less than the preset time T4, among which, the water temperature filter coefficient k1 when the high-speed fan is turned on is less than the water temperature filter coefficient k1 when the low-speed fan is turned on, and the water temperature filter coefficient k1 when the low-speed fan is turned on is less than the water temperature filter coefficient k1 when the fan is not turned on; the vehicle speed filter coefficient k2 when the high-speed fan is turned on is less than the vehicle speed filter coefficient k2 when the low-speed fan is turned on, and the vehicle speed filter coefficient k2 when the low-speed fan is turned on is less than the vehicle speed filter coefficient k2 when the fan is not turned on.

[0025] In some optional embodiments, the dynamic control and intelligent control optimization of the fan control based on the filtered actual water temperature and the fan control based on the intake air temperature and the filtered vehicle speed based on the real-time performance of the cooling system include:

[0026] Once high-intensity knock, continuous medium-intensity knock or continuous low-intensity knock is detected, the current engine speed, the density of the fresh air entering the cylinder, the actual water temperature after filtering, the target water temperature, the vehicle speed after filtering and the intake temperature are recorded. When the current engine speed, the density of the fresh air entering the cylinder, the actual water temperature after filtering, the target water temperature, the vehicle speed after filtering and the intake temperature are all the same and the stable time exceeds the preset time T5, it is considered that the operating condition 1 is the same; when the current engine speed, the density of the fresh air entering the cylinder, the actual water temperature after filtering, the target water temperature and the intake temperature are all the same and the stable time exceeds the preset time T5, it is considered that the operating condition 2 is the same; when the current engine speed, the density of the fresh air entering the cylinder and the vehicle speed after filtering are all the same and the stable time exceeds the preset time T5, it is considered that the operating condition 3 is the same;

[0027] If the number of high-intensity knocks exceeds the preset number and meets working condition 2 but does not meet working condition 1, the average value of the filtered vehicle speed during working condition 2, v, is read. Avg1 , and based on the average value v obtained under high intensity knock Avg1 Updating the preset value D3 and the preset value D4 based on high-intensity knock, wherein the number of high-intensity knock occurrences is reset to zero and then accumulated again after any update of the preset value D3 or the preset value D4;

[0028] If the number of consecutive medium-intensity knocks exceeds the preset number and meets working condition 2 but does not meet working condition 1, the average value of the filtered vehicle speed during working condition 2 is read v Avg1 , and based on the average value v obtained under continuous medium intensity knock Avg1 Update the preset value D3 and preset value D4 based on continuous moderate intensity knock, wherein the number of continuous moderate intensity knock occurrences is reset to zero and then accumulated again after any update of D3 or D4;

[0029] If the number of consecutive low-intensity knocks exceeds the preset number and meets working condition 2 but does not meet working condition 1, the average value of the filtered vehicle speed during working condition 2 is read v Avg1 , and based on the average value v under continuous low-intensity knock Avg1 Update the preset value D3 and the preset value D4 based on continuous low-intensity knock, wherein the number of continuous low-intensity knock occurrences is reset to zero and then accumulated again after any update of D3 or D4;

[0030] If the number of high-intensity knocks exceeds the preset number and meets working condition 3 but does not meet working condition 2, the target water temperature average value T under working condition 3 is read. CoolantDsrdAvg1 , and based on the average value T under high intensity detonation CoolantDsrdAvg1 Updating the preset value D1 and the preset value D2 based on high-intensity knock, wherein the number of high-intensity knock occurrences is reset to zero and then accumulated again after any update of D1 or D2;

[0031] If the number of consecutive medium-intensity knocks exceeds the preset number and meets working condition 3 but does not meet working condition 2, the target water temperature average value T under working condition 3 is read. CoolantDsrdAvg1 , and based on the target water temperature average value T under continuous medium intensity detonation CoolantDsrdAvg1 Update the preset value D1 and preset value D2 based on continuous moderate intensity knock, wherein the number of continuous moderate intensity knock occurrences is reset to zero and then accumulated again after any update of D1 or D2;

[0032] If the number of consecutive low-intensity knocks exceeds the preset number and meets working condition 3 but does not meet working condition 2, the target water temperature average value T under working condition 3 is read. CoolantDsrdAvg1 , and based on the target water temperature average value T under continuous low-intensity detonation CoolantDsrdAvg1 Update the preset value D1 and the preset value D2 based on continuous low-intensity knock, wherein the number of continuous low-intensity knock occurrences is reset to zero and then accumulated again after any update of D1 or D2;

[0033] If when the fan is on, if high-intensity knock, continuous medium-intensity knock and continuous low-intensity knock all occur, and the corresponding cumulative vehicle mileage during engine operation exceeds the preset mileage, the update coefficients of D1, D2, D3 and D4 will be adjusted. Among them, the cumulative vehicle mileage will be cleared immediately after the update coefficients of D1, D2, D3 and D4 increase.

[0034] In some optional embodiments, the average value v obtained under high intensity detonation is Avg1 Update the preset value D3 and preset value D4 based on high intensity knock, including: if the fan is in the high speed fan on state in working condition 2, then in the subsequent driving cycle, update the actual vehicle speed to be no greater than the average value v of the filtered vehicle speed Avg1 The preset values ​​D3 and D4 under the above conditions are respectively equal to the first multiples of D3 and D4 after the last update; if the fan is in the low-speed fan-on state in working condition 2, then in the subsequent driving cycle, the updated actual vehicle speed is not greater than the average value v of the filtered vehicle speed Avg1 The preset value D4 under the condition is D4, which is equal to the second multiple of D4 after the last update; if the fan is not turned on in working condition 2, the actual vehicle speed is updated in the subsequent driving cycle and is not greater than the average value v of the filtered vehicle speed. Avg1 The preset value D4 under the above condition is D4, where D4 is equal to the third multiple of D4 after the last update, wherein the values ​​of the first multiple, the second multiple and the third multiple decrease in sequence;

[0035] The average value v obtained under continuous medium intensity knock Avg1Update the preset value D3 and preset value D4 based on continuous medium intensity knock, including: if the fan is in the high-speed fan on state in working condition 2, then in the subsequent driving cycle, update the actual vehicle speed to be no greater than the average value v of the filtered vehicle speed Avg1 The preset values ​​D3 and D4 under the above conditions are respectively equal to the fourth multiple of D3 and D4 after the last update; if the fan is in the low speed fan on state in working condition 2, then in the subsequent driving cycle, the updated actual vehicle speed is not greater than the average value v of the filtered vehicle speed Avg1 The preset value D4 under the condition is D4, which is equal to the fifth multiple of D4 after the last update; if the fan is not turned on in working condition 2, the actual vehicle speed is updated in the subsequent driving cycle and is not greater than the average value v of the filtered vehicle speed. Avg1 The preset value D4 under the above condition is D4, where D4 is equal to the sixth multiple of D4 after the last update, wherein the values ​​of the fourth multiple, the fifth multiple and the sixth multiple decrease in sequence;

[0036] The average value v based on continuous low-intensity knock Avg1 Update the preset value D3 and preset value D4 based on continuous low-intensity knock, including: if the fan is in the high-speed fan on state in working condition 2, then in the subsequent driving cycle, the actual vehicle speed is updated to be no greater than the average vehicle speed v after filtering Avg1 The preset values ​​D3 and D4 under the above conditions are respectively equal to the seventh multiple of D3 and D4 after the last update; if the fan is in the low speed fan on state in working condition 2, then in the subsequent driving cycle, the updated actual vehicle speed is not greater than the average vehicle speed v after filtering. Avg1 The preset value D4 under the condition is D4, which is equal to the eighth multiple of D4 after the last update; if the fan is not turned on in working condition 2, the actual vehicle speed is updated in the subsequent driving cycle and is not greater than the average vehicle speed v after filtering. Avg1 The preset value D4 under the above condition is D4, which is equal to the ninth multiple of D4 after the last update, wherein the values ​​of the seventh multiple, the eighth multiple, and the ninth multiple decrease in sequence;

[0037] Among them, the values ​​of the first multiple, the fourth multiple and the seventh multiple decrease in sequence, the values ​​of the second multiple, the fifth multiple and the eighth multiple decrease in sequence, and the values ​​of the third multiple, the sixth multiple and the ninth multiple decrease in sequence.

[0038] In some optional embodiments, the average value T based on the occurrence of high intensity detonation CoolantDsrdAvg1 Update the preset value D1 and preset value D2 based on high intensity knock, including: if the fan is in the high speed fan on state in working condition 3, then in the subsequent driving cycle, the updated target water temperature is not greater than the target water temperature average value T CoolantDsrdAvg1The preset values ​​D1 and D2 under the above conditions are equal to the tenth multiple of D1 and D2 after the last update respectively; if the fan is in the low speed fan on state in working condition 3, then in the subsequent driving cycle, the updated target water temperature is not greater than the target water temperature average value T CoolantDsrdAvg1 The preset value D2 under the condition is D2, which is equal to the eleventh multiple of D2 after the last update; if the fan is not turned on in working condition 3, the updated target water temperature is not greater than the target water temperature average value T in the subsequent driving cycle. CoolantDsrdAvg1 The preset value D2 under the above condition is D2, which is equal to the twelfth multiple of D2 after the last update, wherein the values ​​of the tenth multiple, the eleventh multiple, and the twelfth multiple decrease in sequence;

[0039] The target water temperature average value T under continuous medium intensity detonation is CoolantDsrdAvg1 Update the preset value D1 and preset value D2 based on continuous medium intensity knock, including: if the fan is in the high-speed fan on state in working condition 3, then in the subsequent driving cycle, the updated target water temperature is not greater than the target water temperature average value T CoolantDsrdAvg1 The preset values ​​D1 and D2 under the above conditions are equal to the thirteenth multiple of D3 and D4 after the last update respectively; if the fan is in the low speed fan on state in working condition 3, then in the subsequent driving cycle, the updated target water temperature is not greater than the target water temperature average value T CoolantDsrdAvg1 The preset value D2 under the condition is D2, which is equal to the fourteenth multiple of D2 after the last update; if the fan is not turned on in working condition 3, the updated target water temperature is not greater than the target water temperature average value T in the subsequent driving cycle. CoolantDsrdAvg1 The preset value D2 under the above condition is D2, which is equal to the fifteenth multiple of D2 after the last update, wherein the values ​​of the thirteenth multiple, the fourteenth multiple, and the fifteenth multiple decrease in sequence;

[0040] The target water temperature average value T under continuous low-intensity detonation is CoolantDsrdAvg1 Update the preset value D1 and preset value D2 based on continuous low-intensity knock, including: if the fan is in the high-speed fan on state in working condition 3, then in the subsequent driving cycle, the updated target water temperature is not greater than the target water temperature average value T CoolantDsrdAvg1 The preset values ​​D1 and D2 under the above conditions are equal to the sixteenth multiple of D1 and D2 after the last update respectively; if the fan is in the low speed fan on state in working condition 3, then in the subsequent driving cycle, the updated target water temperature is not greater than the target water temperature average value T CoolantDsrdAvg1 The preset value D2 under the condition is D2, which is equal to the seventeenth multiple of D2 after the last update; if the fan is not turned on in working condition 3, the updated target water temperature is not greater than the target water temperature average value T in the subsequent driving cycle. CoolantDsrdAvg1 The preset value D2 under the above condition is D2, where D2 is equal to the eighteenth multiple of D2 after the last update, wherein the values ​​of the sixteenth multiple, the seventeenth multiple, and the eighteenth multiple decrease in sequence;

[0041] Among them, the values ​​of the tenth multiple, the thirteenth multiple and the sixteenth multiple decrease in sequence, the values ​​of the eleventh multiple, the fourteenth multiple and the seventeenth multiple decrease in sequence, and the values ​​of the twelfth multiple, the fifteenth multiple and the eighteenth multiple decrease in sequence.

[0042] In some optional implementation schemes, the update coefficients of D1, D2, D3 and D4 are saved after being updated. In the next vehicle driving cycle, the table values ​​determined by the fan control based on water temperature and the fan control based on intake temperature and vehicle speed will be used and multiplied by the previously saved update coefficients of D1, D2, D3 and D4 to obtain the final D1, D2, D3 and D4.

[0043] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0044] The present invention considers fan control based on water temperature by: 1) considering that the fan needs to be turned on when the water temperature is too high to avoid poor vehicle power, economy and emissions, and to avoid the occurrence of knock; 2) considering fan control based on intake air temperature and vehicle speed because a combination of a high intake air temperature and a low vehicle speed will increase the risk of engine knock; 3) the purpose of dynamic control and intelligent control optimization based on the real-time performance of the cooling system is that the engine operating conditions are transient and complex, and dynamic control optimization is performed in real time, while improving control optimization for cooling system aging to provide control accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The figure is a flow chart of a method for controlling a vehicle radiator fan provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0047] In the examples of the present invention, “first”, “second”, etc. are used to distinguish different objects rather than to describe a specific order or sequence.

[0048] A common engine cooling system includes an engine water outlet 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 (which may include an electronic thermostat), and a radiator fan.

[0049] The engine water outlet temperature sensor is used to detect the cooling water temperature at the engine water outlet, referred to as the water temperature sensor, and detects the actual water temperature of the engine;

[0050] Atmospheric temperature sensor or atmospheric temperature signal, the engine cooling system is hard-wired to the atmospheric temperature sensor, or receives the atmospheric temperature signal through a communication such as a CAN network;

[0051] Vehicle speed sensor or vehicle speed signal, the engine cooling system is hard-wired to the vehicle speed sensor, or receives the vehicle speed signal through network CAN communication;

[0052] The water pump controls the circulation of cooling water;

[0053] Thermal management module: When the thermal management module is turned on, it means that part of the cooling water is returned to the engine water inlet after being cooled by the radiator;

[0054] The radiator fan has only two levels, i.e. two speeds, low speed and high speed with two fixed powers, which are used to cool the cooling water flowing through the radiator.

[0055] like Figure 1 As shown, the present invention mainly performs dynamic control and intelligent control optimization based on water temperature-based fan control, intake air temperature and vehicle speed-based fan control, and real-time performance of the cooling system. 1) The reason for considering fan control based on water temperature is that the fan needs to be turned on when the water temperature is too high to avoid poor vehicle power economy and emissions, and to avoid the occurrence of knock; 2) The reason for fan control based on intake air temperature and vehicle speed is that when the intake air temperature is too high and the vehicle speed is too low, the risk of engine knock increases; 3) The purpose of dynamic control and intelligent control optimization based on the real-time performance of the cooling system is to perform dynamic control optimization in real time as the engine operating conditions are transient and complex, and to improve control optimization such as cooling system aging to provide control accuracy.

[0056] First, the actual water temperature and vehicle speed are filtered to improve the problem of low cooling system water temperature control accuracy caused by frequent changes in fan control due to transient and complex engine operating conditions.

[0057] 1) Filter the actual water temperature:

[0058] T CoolantAct (N) = k1 × [T CoolantActRaw -T CoolantAct (N-1)]+T CoolantAct (N-1), where N=1, 2, 3..., T CoolantAct (N-1) is the actual water temperature after filtering at time N-1; T CoolantAct (N) is the actual water temperature after filtering at time N; the time difference between time N-1 and time N is a fixed update period ΔT (10ms in this example); TCoolantActRaw is the original actual water temperature collected by the water temperature sensor at time N. In particular, when T CoolantAct The filtered actual water temperature at (0) is equal to the original actual water temperature collected by the water temperature sensor when the vehicle is just powered on. k1 is the filter coefficient. The smaller the filter coefficient k1, the smoother the actual water temperature after filtering. k1 is within the range of greater than 0 and less than 1.

[0059] 2) Filter the vehicle speed:

[0060] v(N)=k2×[v Raw -v(N-1)]+v(N-1), where N=1, 2, 3..., v(N-1) is the filtered vehicle speed at time N-1; v(N) is the filtered vehicle speed at time N; the time difference between time N-1 and time N is a fixed update period ΔT (10ms in this example); v Raw is the raw, unprocessed vehicle speed signal at time N. Specifically, the filtered vehicle speed at v(0) is equal to the raw, unprocessed vehicle speed signal immediately after the vehicle is powered on. k2 is the filter coefficient. The smaller the filter coefficient k2, the smoother the filtered vehicle speed. k2 is within the range of greater than 0 and less than 1. The settings of the water temperature filter coefficient k1 and the vehicle speed filter coefficient k2 will be discussed later.

[0061] The following will introduce in detail the fan control based on water temperature, fan control based on intake temperature and vehicle speed, as well as dynamic control and intelligent control optimization based on the real-time performance of the cooling system.

[0062] 1. Fan control based on water temperature

[0063] High-speed fan start conditions:

[0064] 1) The concept of a high-speed fan on-timer is proposed. Its logic is: if the difference between the actual filtered water temperature and the target water temperature is less than a preset value A1 (preset value A1 is equal to preset value B1 minus margin C1, which depends on the atmospheric temperature), the high-speed fan on-timer is reset to 0;

[0065] If the difference between the actual filtered water temperature and the target water temperature exceeds a preset value B1 (the preset value B1 depends on the target water temperature), the time when this condition (i.e., the difference between the actual filtered water temperature and the target water temperature exceeds the preset value B1) is accumulated and recorded as the time of the high-speed fan on timer; if the difference between the actual filtered water temperature and the target water temperature does not exceed the preset value B1 and is not less than the preset value A1, the high-speed fan on timer time remains unchanged. Once the high-speed fan on timer time exceeds the preset time T1, the high-speed fan on condition one is met; otherwise, the high-speed fan on condition one is not met.

[0066] The preset value B1 depends on the target water temperature, and the margin C1 depends on the atmospheric water temperature. The calibration data for B1 and C1 in this example are as follows. The calibration is based on the following: During vehicle development and testing, the high-speed fan should be kept as low as possible while ensuring that the difference between the actual and target water temperatures is within ±4°C. This reduces the increase in the fan's electrical load and improves fuel economy.

[0067] The preset value B1 is shown in Table 1 below:

[0068] Table 1

[0069]

[0070] The margin C1 is shown in Table 2 below:

[0071] Table 2

[0072]

[0073] 2) If the actual water temperature after filtering exceeds the preset value D1 (the preset value D1 depends on the target water temperature), the second condition for turning on the high-speed fan is met; if the actual water temperature after filtering does not exceed the preset value E1 (the preset value E1 is equal to the preset value D1 minus the margin F1), the second condition for turning on the high-speed fan is not met.

[0074] The preset value D1 depends on the target water temperature. The calibration data for D1 in this example is shown in Table 3 below. The calibration is also based on the following: During vehicle development and testing, the high-speed fan should be kept as low as possible while ensuring that the difference between the actual water temperature and the target water temperature is within the range of ±4°C. This reduces the increase in the fan electrical load and improves fuel economy.

[0075] Table 3

[0076]

[0077] When the temperature difference increases, the engine performance abnormality will be reflected earlier than the cooling system. In other words, the increase in temperature difference will be reflected later than the engine performance abnormality. That is, through the above two redundant design methods, the water temperature difference is strictly controlled within the range of ±2℃.

[0078] Low speed fan start conditions:

[0079] 1) The concept of a low-speed fan on timer is proposed. Its logic is: if the difference between the actual filtered water temperature and the target water temperature is less than a preset value A2 (preset value A2 is equal to preset value B2 minus margin C2, which depends on the atmospheric temperature), the low-speed fan on timer is reset to 0;

[0080] If the difference between the actual water temperature after filtering and the target water temperature exceeds a preset value B2 (the preset value B2 depends on the target water temperature), the time when this condition (i.e., the difference between the actual water temperature after filtering and the target water temperature exceeds the preset value B2) is accumulated and recorded as the time for the low-speed fan to start the timer;

[0081] If the difference between the actual water temperature after filtering and the target water temperature does not exceed the preset value B2 and is not less than the preset value A2, the low-speed fan on timer time remains unchanged. Once the low-speed fan on timer time exceeds the preset time T2, the low-speed fan on condition is met, otherwise the low-speed fan on condition is not met;

[0082] The preset value B2 depends on the target water temperature, and the margin C2 depends on the atmospheric water temperature. The calibration data for B2 and C2 in this example are as follows. The calibration is based on the following: During vehicle development and testing, the fan should be kept as close to the target water temperature as possible, ensuring that the difference between the actual water temperature and the target water temperature is within ±4°C. This reduces the increase in the fan's electrical load and improves fuel economy.

[0083] The preset value B2 is shown in Table 4 below:

[0084] Table 4

[0085]

[0086] The preset value C2 is shown in Table 5 below:

[0087] Table 5

[0088]

[0089] 2) If the actual water temperature after filtering exceeds the preset value D2 (the preset value D2 depends on the target water temperature), the second low-speed fan start-up condition is met; if the actual water temperature after filtering does not exceed the preset value E2 (the preset value E2 is equal to the preset value D2 minus the margin F2), the second low-speed fan start-up condition is not met.

[0090] The preset value D2 depends on the target water temperature. The D2 calibration data for this example is shown in Table 6 below. The calibration is also based on the following: During vehicle development and testing, the low-speed fan should be kept as low as possible while ensuring that the difference between the actual water temperature and the target water temperature is within the range of ±4°C. This will reduce the increase in the fan electrical load and improve fuel economy.

[0091] Table 6

[0092]

[0093] When the temperature difference increases, abnormal engine performance will be reflected earlier than the cooling system. In other words, the increase in temperature difference will be reflected later than the abnormal engine performance. Therefore, through the above two redundant design methods, the water temperature difference is strictly controlled within the range of ±4℃, while the fan electrical load is minimized as much as possible.

[0094] 2. Fan control based on intake air temperature and vehicle speed

[0095] High-speed fan start conditions:

[0096] If the actual intake air temperature exceeds the preset value D3 (the preset value D3 depends on the vehicle speed after filtering), the high-speed fan start-up condition three is met; if the actual intake air temperature does not exceed the preset value E3 (the preset value E3 is equal to the preset value D3 minus the margin F3), the high-speed fan start-up condition three is not met.

[0097] The preset value D3 depends on the filtered vehicle speed. The D3 calibration data for this example is shown in Table 7 below. This calibration is based on the following: During vehicle development and testing, testing and verification are primarily conducted under high-temperature conditions with high intake air temperatures. After knock control and ignition control performance calibration is complete, no high-intensity knock occurs, and no continuous moderate-intensity knock occurs. In this example, high-intensity knock is defined as a knock that causes an ignition angle delay exceeding 8°; continuous moderate-intensity knock is defined as a knock that causes an ignition angle delay of no more than 8° but greater than 4°, with continuous, uninterrupted combustion lasting for more than 2 seconds.

[0098] Table 7

[0099]

[0100] Low speed fan start conditions:

[0101] If the actual intake air temperature exceeds the preset value D4 (the preset value D4 depends on the vehicle speed after filtering), the low-speed fan start-up condition three is met; if the actual intake air temperature does not exceed the preset value E4 (the preset value E4 is equal to the preset value D4 minus the margin F4), the low-speed fan start-up condition three is not met.

[0102] The preset value D4 depends on the filtered vehicle speed. The D4 calibration data for this example is shown in Table 8 below. This calibration is based on the following: During vehicle development and testing, testing and verification are primarily conducted under high-temperature conditions with high intake air temperatures. After knock control and ignition control performance calibration is complete, no moderate-intensity knock occurs, and no continuous low-intensity knock occurs. In this example, moderate-intensity knock is defined as a knock that causes an ignition angle delay exceeding 4°; continuous low-intensity knock is defined as a knock that causes an ignition angle delay of no more than 4° but greater than 2°, with continuous, uninterrupted combustion lasting for more than 5 seconds.

[0103] Table 8

[0104]

[0105] In the above three cases, if any one of the high-speed fan triggering conditions is met (ie, one of the high-speed fan start-up condition 1, the high-speed fan start-up condition 2, or the high-speed fan start-up condition 3 is met), the high-speed fan start-up condition is met.

[0106] In the above three cases, if any one of the low-speed fan triggering conditions is met (ie, one of the low-speed fan start-up condition 1, the low-speed fan start-up condition 2, or the low-speed fan start-up condition 3 is met), the low-speed fan start-up condition is met.

[0107] When the high-speed fan start-up conditions are met, the high-speed fan will be triggered to turn on, and its minimum start-up time must not be less than the preset time T3 (the first setting of T3 time is 5s); when the low-speed fan start-up conditions are met, the low-speed fan will be triggered to turn on, and its minimum start-up time must not be less than the preset time T4 (the first setting of T4 time is 8s).

[0108] The water temperature filter coefficient k1 when the high-speed fan is on is smaller than the water temperature filter coefficient k1 when the low-speed fan is on, and the water temperature filter coefficient k1 when the low-speed fan is on is smaller than the water temperature filter coefficient k1 when the fan is not on. Similarly, the vehicle speed filter coefficient k2 when the high-speed fan is on is smaller than the vehicle speed filter coefficient k2 when the low-speed fan is on, and the vehicle speed filter coefficient k2 when the low-speed fan is on is smaller than the vehicle speed filter coefficient k2 when the fan is not on. That is, the values ​​of the filter coefficients k1 and k2 are updated under different fan states. The purpose of this approach is that the high-speed fan has a larger power and the filter coefficient is set relatively small, which can avoid frequent fluctuations in the fan turning on and off. Conversely, the low-speed fan has a smaller power but can have a cooling effect. Therefore, the filter coefficient is set smaller relative to when the fan is not on, which can also avoid frequent fluctuations in the fan turning on and off.

[0109] In this example, the water temperature filter coefficient k1 is 0.135 when the high-speed fan is turned on, and the water temperature filter coefficient k1 is 0.241 when the low-speed fan is turned on; the water temperature filter coefficient k1 is 0.267 when the fan is not turned on.

[0110] In this example, the vehicle speed filter coefficient k2 is 0.235 when the high-speed fan is turned on, and the vehicle speed filter coefficient k2 is 0.35 when the low-speed fan is turned on; the vehicle speed filter coefficient k2 is 0.452 when the fan is not turned on.

[0111] 3. Dynamic control and intelligent control optimization based on the real-time performance of the cooling system.

[0112] 1) Once any of the three conditions of high-intensity knock, continuous medium-intensity knock, and continuous low-intensity knock is detected, the current engine speed, the density of fresh air entering the cylinder, the actual water temperature after filtering, the target water temperature, the vehicle speed after filtering, and the intake temperature parameter information are recorded. If the current engine speed, the density of fresh air entering the cylinder, the actual water temperature after filtering, the target water temperature, the vehicle speed after filtering, and the intake temperature are the same and stable (the method for judging the stability of each parameter is that the difference between the maximum and minimum values ​​of the parameter divided by its average value does not exceed ±2%) for a time period exceeding T5 (T5 in this example is 5s), then it is considered that the operating condition 1 is the same; When the current engine speed, the density of the fresh air intake entering the cylinder, the actual water temperature after filtering, the target water temperature, and the intake temperature are all the same and stable (the method for judging the stability of each parameter is that the difference between the maximum and minimum values ​​of the parameter divided by its average value does not exceed ±2%) for a time exceeding T5 (T5 in this example is 5s), then the operating condition 2 is considered to be the same; when the current engine speed, the density of the fresh air intake entering the cylinder, and the vehicle speed after filtering are all the same and stable (the method for judging the stability of each parameter is that the difference between the maximum and minimum values ​​of the parameter divided by its average value does not exceed ±2%) for a time exceeding T5 (T5 in this example is 5s), then the operating condition 3 is considered to be the same.

[0113] That is, consider these parameters: the current engine speed, the density of the fresh air intake into the cylinder, the actual water temperature after filtering, the target water temperature, the vehicle speed after filtering and the intake temperature parameter information, among which the current engine speed, the density of the fresh air intake into the cylinder, the actual water temperature after filtering, the target water temperature, the vehicle speed after filtering and the intake temperature are regarded as operating condition 1; the current engine speed, the density of the fresh air intake into the cylinder, the actual water temperature after filtering, the target water temperature, the vehicle speed after filtering and the intake temperature parameter information, among which the current engine speed, the density of the fresh air intake into the cylinder, the actual water temperature after filtering, the target water temperature, the vehicle speed after filtering and the intake temperature are the same and stable (the method for judging the stability of each parameter is that the difference between the maximum and minimum values ​​of the parameter divided by its average value does not exceed ±2%) and the time exceeds T5 (T5 in this example is 5s), then it is considered to be in operating condition 1, and the operating condition is stable, and it is considered that operating condition 1 is the same.

[0114] Among them, the following parameters are considered: current engine speed, fresh air intake density entering the cylinder, actual water temperature after filtering, target water temperature, and intake air temperature, which is regarded as working condition 2.

[0115] Among them, the following parameters are considered: current engine speed, fresh air intake density entering the cylinder, and filtered vehicle speed, which is regarded as working condition 3.

[0116] If the number of high-intensity knocks exceeds the preset number (the preset number is 15. The number of high-intensity knocks is reset to zero after any update of D3 or D4 and then accumulated again), and the working condition 2 is met, but the working condition 1 is not met (that is, the number of high-intensity knocks in working condition 2 exceeds the preset number), then read the filtered average vehicle speed v in working condition 2 Avg1 , then update the preset value D3 and preset value D4 based on high intensity knock, and can be saved after the vehicle is powered off. The specific update method is as follows: a) If the fan is in the high speed fan on state in working condition 2, then in the subsequent driving cycle, the updated actual vehicle speed is not greater than the filtered vehicle speed average v Avg1 The preset values ​​D3 and D4 under the above conditions are respectively equal to the first multiple of D3 and D4 after the last update; b) If the fan is in the low-speed fan-on state in working condition 2, then in the subsequent driving cycle, the updated actual vehicle speed is not greater than the average vehicle speed v after filtering. Avg1 The preset value D4 under the condition is D4, which is equal to the second multiple of D4 after the last update; c) If the fan is not turned on in working condition 2, the actual vehicle speed is updated in the subsequent driving cycle and is not greater than the average vehicle speed v after filtering. Avg1 The preset value D4 is equal to the third multiple of D4 after the last update. In case c, the D4 update coefficient is larger than that in case b. In case c, the fan is not turned on, indicating that the actual water temperature is not too high. There is no need to turn on the fan too quickly, thus minimizing the electrical load.

[0117] The values ​​of the first multiple, the second multiple and the third multiple decrease in sequence. In the embodiment of the present invention, as an exemplary example, the first multiple is 0.95, the second multiple is 0.92, and the third multiple is 0.9.

[0118] If the number of consecutive moderate knocks exceeds the preset number (the preset number is 15, and the number of consecutive moderate knocks is reset to zero after any update of D3 or D4 and then accumulated again), and the working condition 2 is met but the working condition 1 is not met, then the filtered average vehicle speed v under working condition 2 is read. Avg1 , then update the preset value D3 and preset value D4 based on continuous medium intensity knock, and can be saved after the vehicle is powered off. The specific update method is as follows: a) If the fan is in the high-speed fan on state in working condition 2, then in the subsequent driving cycle, the updated actual vehicle speed is not greater than the filtered vehicle speed average v Avg1 The preset values ​​D3 and D4 under the above conditions are respectively equal to the fourth multiple of D3 and D4 after the last update; b) If the fan is in the low speed fan on state in working condition 2, then in the subsequent driving cycle, the updated actual vehicle speed is not greater than the average vehicle speed v after filtering. Avg1The preset value D4 under the condition is D4, which is equal to the fifth multiple of D4 after the last update; c) If the fan is not turned on in working condition 2, the actual vehicle speed is updated in the subsequent driving cycle and is not greater than the average vehicle speed v after filtering. Avg1 The preset value D4 is equal to the sixth multiple of D4 after the last update. In case c, the D4 update coefficient is larger than that in case b. In case c, the fan is not turned on, indicating that the actual water temperature is not too high. There is no need to turn on the fan too quickly, thus minimizing the electrical load.

[0119] The values ​​of the fourth multiple, the fifth multiple, and the sixth multiple decrease in sequence. In the embodiment of the present invention, as an illustrative example, the fourth multiple is 0.97, the fifth multiple is 0.95, and the sixth multiple is 0.92.

[0120] If the number of consecutive low-intensity knocks exceeds the preset number (the preset number is 15, and the number of consecutive low-intensity knocks is reset to zero and then accumulated again after any update of D3 or D4), and the working condition 2 is met but the working condition 1 is not met, then the filtered average vehicle speed v under working condition 2 is read. Avg1 , then update the preset value D3 and preset value D4 based on continuous low-intensity knock, and can be saved after the vehicle is powered off. The specific update method is as follows: a) If the fan is in the high-speed fan on state in working condition 2, then in the subsequent driving cycle, the updated actual vehicle speed is not greater than the filtered vehicle speed average v Avg1 The preset values ​​D3 and D4 under the above conditions are respectively equal to the seventh multiple of D3 and D4 after the last update; b) If the fan is in the low speed fan on state in working condition 2, then in the subsequent driving cycle, the updated actual vehicle speed is not greater than the average vehicle speed v after filtering. Avg1 The preset value D4 under the condition is D4, which is equal to the eighth multiple of D4 after the last update; c) If the fan is not turned on in working condition 2, the actual vehicle speed is updated in the subsequent driving cycle and is not greater than the average vehicle speed v after filtering. Avg1 The preset value D4 is equal to the ninth multiple of D4 after the last update. In case c, the D4 update coefficient is larger than that in case b. Since the fan is not turned on in case c, the actual water temperature is not too high, so there is no need to turn on the fan too quickly, thus minimizing the electrical load.

[0121] The values ​​of the seventh multiple, the eighth multiple, and the ninth multiple decrease in sequence. In the embodiment of the present invention, as an illustrative example, the seventh multiple is 0.98, the eighth multiple is 0.97, and the ninth multiple is 0.95.

[0122] In the above three cases, after high-intensity knock occurs, the update coefficients of the preset values ​​D3 and D4 are smaller than the update coefficients of the adjustment parameters D3 and D4 after continuous medium-intensity knock occurs, that is, the adjustment amplitude is larger, which avoids further strengthening of the knock, thereby protecting the engine; after continuous medium-intensity knock occurs, the update coefficients of the preset values ​​D3 and D4 are smaller than the update coefficients of the adjustment parameters D3 and D4 after continuous low-intensity knock occurs, that is, the adjustment amplitude is larger, which avoids further strengthening of the knock, thereby protecting the engine.

[0123] If the number of high-intensity knocks exceeds the preset number (the preset number is 15, and the number of high-intensity knocks is reset to zero after any update of D1 or D2 and then accumulated again), and the working condition 3 is met, but the working condition 2 is not met (that is, the number of high-intensity knocks occurring under working condition 3 exceeds the preset number), then read the target water temperature average value T under working condition 3. CoolantDsrdAvg1 , then update the preset value D1 and preset value D2 based on high intensity knock, and can be saved after the vehicle is powered off. The specific update method is as follows: a) If the fan is in the high-speed fan on state in working condition 3, then in the subsequent driving cycle, the updated target water temperature is not greater than the target water temperature average value T CoolantDsrdAvg1 The preset values ​​D1 and D2 under the above conditions are equal to the tenth multiple of D1 and D2 after the last update respectively; b) If the fan is in the low speed fan on state in working condition 3, the updated target water temperature is not greater than the target water temperature average value T in the subsequent driving cycle. CoolantDsrdAvg1 The preset value D2 under the above conditions is D2, which is equal to the eleventh multiple of D2 after the last update; c) If the fan is not turned on in working condition 3, the updated target water temperature is not greater than the target water temperature average value T in subsequent driving cycles. CoolantDsrdAvg1 The preset value D2 is equal to the twelfth multiple of D2 after the last update. In case c, the D2 update coefficient is larger than that in case b. In case c, the fan is not turned on, indicating that the actual water temperature is not too high. There is no need to turn on the fan too quickly, thus minimizing the electrical load.

[0124] The values ​​of the tenth multiple, the eleventh multiple, and the twelfth multiple decrease in sequence. In the embodiment of the present invention, as an illustrative example, the tenth multiple is 0.92, the eleventh multiple is 0.9, and the twelfth multiple is 0.88.

[0125] If the number of consecutive moderate knocks exceeds the preset number (the preset number is 15, and the number of consecutive moderate knocks is reset to zero after any update of D1 or D2 and then accumulated again), and the working condition 3 is met but the working condition 2 is not met, then the target water temperature average value T under working condition 3 is read. CoolantDsrdAvg1, then update the preset value D1 and preset value D2 based on continuous medium intensity knock, and can be saved after the vehicle is powered off. The specific update method is as follows: a) If the fan is in the high-speed fan on state in working condition 3, then in the subsequent driving cycle, the updated target water temperature is not greater than the target water temperature average value T CoolantDsrdAvg1 The preset values ​​D1 and D2 under the above conditions are respectively equal to the thirteenth multiple of D1 and D2 after the last update; b) If the fan is in the low-speed fan-on state in working condition 3, the updated target water temperature is not greater than the target water temperature average value T in the subsequent driving cycle. CoolantDsrdAvg1 The preset value D2 under the above conditions is D2, which is equal to the fourteenth multiple of D2 after the last update; c) If the fan is not turned on in working condition 3, the updated target water temperature is not greater than the target water temperature average value T in subsequent driving cycles. CoolantDsrdAvg1 The preset value D2 is equal to the fifteenth multiple of D2 after the last update. In case c, the D2 update coefficient is larger than that in case b. In case c, the fan is not turned on, indicating that the actual water temperature is not too high. There is no need to turn on the fan too quickly, thus minimizing the electrical load.

[0126] The values ​​of the thirteenth multiple, the fourteenth multiple, and the fifteenth multiple decrease in sequence. In the embodiment of the present invention, as an illustrative example, the thirteenth multiple is 0.95, the fourteenth multiple is 0.92, and the fifteenth multiple is 0.9.

[0127] If the number of consecutive low-intensity knocks exceeds the preset number (the preset number is 15, and the number of consecutive low-intensity knocks is reset to zero after any update of D1 or D2 and then accumulated again), and the working condition 3 is met but the working condition 2 is not met, then the target water temperature average value T under working condition 3 is read. CoolantDsrdAvg1 , then update the preset value D1 and preset value D2 based on continuous low-intensity knock, and can be saved after the vehicle is powered off. The specific update method is as follows: a) If the fan is in the high-speed fan on state in working condition 3, then in the subsequent driving cycle, the updated target water temperature is not greater than the target water temperature average value T CoolantDsrdAvg1 The preset values ​​D1 and D2 under the above conditions are respectively equal to the sixteenth multiple of D1 and D2 after the last update; b) If the fan is in the low-speed fan-on state in working condition 3, the updated target water temperature is not greater than the target water temperature average value T in the subsequent driving cycle. CoolantDsrdAvg1 The preset value D2 under the above conditions is D2, which is equal to the seventeenth multiple of D2 after the last update; c) If the fan is not turned on in working condition 3, the updated target water temperature is not greater than the target water temperature average value T in subsequent driving cycles. CoolantDsrdAvg1The preset value D2 is equal to the eighteenth multiple of D2 after the last update. In case c, the D2 update coefficient is larger than that in case b. In case c, the fan is not turned on, indicating that the actual water temperature is not too high. There is no need to turn on the fan too quickly, thus minimizing the electrical load.

[0128] The values ​​of the sixteenth multiple, the seventeenth multiple, and the eighteenth multiple decrease in sequence. In the embodiment of the present invention, as an illustrative example, the sixteenth multiple is 0.96, the seventeenth multiple is 0.94, and the eighteenth multiple is 0.92.

[0129] In the above three cases, after high-intensity knock occurs, the update coefficients of the preset values ​​D1 and D2 are smaller than the update coefficients of the adjustment parameters D1 and D2 after continuous medium-intensity knock occurs, that is, the adjustment amplitude is larger, which avoids further strengthening of the knock, thereby protecting the engine; after continuous medium-intensity knock occurs, the update coefficients of the preset values ​​D1 and D2 are smaller than the update coefficients of the adjustment parameters D1 and D2 after continuous low-intensity knock occurs, that is, the adjustment amplitude is larger, which avoids further strengthening of the knock, thereby protecting the engine.

[0130] If the fan is on (regardless of whether the low-speed fan is on or the high-speed fan is on), if high-intensity knock, continuous medium-intensity knock, and continuous low-intensity knock all occur, and the corresponding cumulative vehicle mileage during engine operation (the cumulative vehicle mileage is immediately cleared after the D1, D2, D3, and D4 update coefficients increase) exceeds the preset mileage (the preset mileage in this example is 5 kilometers), then adjust the update coefficients of D1, D2, D3, and D4. In this example, D1, D2, D3, and D4 are equal to 1.005 times the D1, D2, D3, and D4 after the last update (that is, the update coefficients increase).

[0131] The priority of the above seven "if" judgments is getting lower and lower. Only one of them is executed in each calculation operation cycle (the operation cycle in this example is 10ms). That is, after the first "if" is satisfied, no other "if" is allowed to run in this operation cycle.

[0132] The update coefficients of D1, D2, D3, and D4 are saved after the power is turned off. In the next vehicle driving cycle, the table values ​​determined by the fan control based on water temperature and the fan control based on intake temperature and vehicle speed will be used. These values ​​will be multiplied by the previously saved update coefficients of D1, D2, D3, and D4 to obtain the final D1, D2, D3, and D4.

[0133] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, or two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0134] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for controlling a vehicle radiator fan, characterized in that: include: Filter the actual water temperature and vehicle speed; Controlling the fan based on the actual filtered water temperature, wherein the controlling the fan based on the actual filtered water temperature includes turning on a high-speed fan based on the actual filtered water temperature and turning on a low-speed fan based on the actual filtered water temperature; Controlling the fan based on the intake air temperature and the filtered vehicle speed, wherein the control of the fan by the intake air temperature and the filtered vehicle speed includes turning on the high-speed fan based on the intake air temperature and the filtered vehicle speed and turning on the low-speed fan based on the intake air temperature and the filtered vehicle speed; Dynamically control and intelligently optimize fan control based on filtered actual water temperature and fan control based on intake air temperature and filtered vehicle speed based on the real-time performance of the cooling system; By T CoolantAct (N) = k1 × [T CoolantActRaw -T CoolantAct (N-1)]+T CoolantAct (N-1) Filter the actual water temperature, where N = 1, 2, 3..., T CoolantAct (N-1) is the actual water temperature after filtering at time N-1; T CoolantAct (N) is the actual water temperature after filtering at time N; the time difference between time N-1 and time N is the fixed update period ΔT; T CoolantActRaw is the original actual water temperature collected by the water temperature sensor at time N; k1 is the water temperature filter coefficient; From v(N)=k2×[v Raw -v(N-1)]+v(N-1) is used to filter the vehicle speed, where N=1, 2, 3..., v(N-1) is the filtered vehicle speed at time N-1; v(N) is the filtered vehicle speed at time N; the time difference between time N-1 and time N is a fixed update period ΔT; v Raw is the original unprocessed vehicle speed signal at time N; k2 is the vehicle speed filter coefficient.

2. The method according to claim 1, characterized in that The high-speed fan is turned on based on the actual water temperature after filtering, including: If the difference between the actual water temperature after filtering and the target water temperature is less than the preset value A1, where the preset value A1 is equal to the preset value B1 minus the margin C1, and the margin C1 depends on the atmospheric temperature, the high-speed fan on timer is reset to 0; if the difference between the actual water temperature after filtering and the target water temperature exceeds the preset value B1, where the preset value B1 depends on the target water temperature, the time when the difference between the actual water temperature after filtering and the target water temperature exceeds the preset value B1 is accumulated, and the accumulated time is used as the time recorded by the high-speed fan on timer; if the difference between the actual water temperature after filtering and the target water temperature does not exceed the preset value B1 and is not less than the preset value A1, the high-speed fan on timer remains unchanged; if the high-speed fan on timer exceeds the preset time T1, the high-speed fan on condition one is met, otherwise the high-speed fan on condition one is not met; If the actual water temperature after filtering exceeds the preset value D1, where the preset value D1 depends on the target water temperature, then the second condition for turning on the high-speed fan is met. If the actual water temperature after filtering does not exceed the preset value E1, where the preset value E1 is equal to the preset value D1 minus the margin F1, then the second condition for turning on the high-speed fan is not met.

3. The method according to claim 2, characterized in that The low-speed fan start-up based on the filtered actual water temperature includes: If the difference between the actual water temperature after filtering and the target water temperature is less than the preset value A2, where the preset value A2 is equal to the preset value B2 minus the margin C2, and the margin C2 depends on the atmospheric temperature, the low-speed fan on timer is reset to 0; if the difference between the actual water temperature after filtering and the target water temperature exceeds the preset value B2, where the preset value B2 depends on the target water temperature, the time when the difference between the actual water temperature after filtering and the target water temperature exceeds the preset value B2 is accumulated, and the accumulated time is used as the time recorded by the low-speed fan on timer; if the difference between the actual water temperature after filtering and the target water temperature does not exceed the preset value B2 and is not less than the preset value A2, the low-speed fan on timer remains unchanged; if the low-speed fan on timer exceeds the preset time T2, the low-speed fan on condition one is met, otherwise the low-speed fan on condition one is not met; If the actual water temperature after filtering exceeds the preset value D2, where the preset value D2 depends on the target water temperature, then the second condition for starting the low-speed fan is met; if the actual water temperature after filtering does not exceed the preset value E2, where the preset value E2 is equal to the preset value D2 minus the margin F2, then the second condition for starting the low-speed fan is not met.

4. The method according to claim 3, characterized in that The high-speed fan activation based on the intake air temperature and the filtered vehicle speed includes: If the actual intake air temperature exceeds the preset value D3, where the preset value D3 depends on the filtered vehicle speed, then the high-speed fan start-up condition three is met; if the actual intake air temperature does not exceed the preset value E3, where the preset value E3 is equal to the preset value D3 minus the margin F3, then the high-speed fan start-up condition three is not met.

5. The method according to claim 4, characterized in that The low-speed fan start based on the intake air temperature and the filtered vehicle speed includes: If the actual intake air temperature exceeds the preset value D4, where the preset value D4 depends on the filtered vehicle speed, the low-speed fan start-up condition three is met; if the actual intake air temperature does not exceed the preset value E4, where the preset value E4 is equal to the preset value D4 minus the margin F4, the low-speed fan start-up condition three is not met.

6. The method according to claim 5, characterized in that If any of the high-speed fan triggering conditions is met, that is, high-speed fan start-up condition 1, high-speed fan start-up condition 2, or high-speed fan start-up condition 3 is met, then the high-speed fan start-up condition is met. After the high-speed fan start-up condition is met, the high-speed fan is triggered to turn on, and the minimum on-time must not be less than the preset time T3; If any one of the conditions for triggering the low-speed fan is met, that is, one of the low-speed fan start-up condition one, the low-speed fan start-up condition two or the low-speed fan start-up condition three is met, then the low-speed fan start-up condition is met. After the low-speed fan start-up condition is met, the low-speed fan is triggered to turn on, and the shortest start-up time shall not be less than the preset time T4, among which, the water temperature filter coefficient k1 when the high-speed fan is turned on is less than the water temperature filter coefficient k1 when the low-speed fan is turned on, and the water temperature filter coefficient k1 when the low-speed fan is turned on is less than the water temperature filter coefficient k1 when the fan is not turned on; the vehicle speed filter coefficient k2 when the high-speed fan is turned on is less than the vehicle speed filter coefficient k2 when the low-speed fan is turned on, and the vehicle speed filter coefficient k2 when the low-speed fan is turned on is less than the vehicle speed filter coefficient k2 when the fan is not turned on.

7. The method according to claim 6, characterized in that The method dynamically controls and intelligently optimizes fan control based on filtered actual water temperature and fan control based on intake air temperature and filtered vehicle speed based on the real-time performance of the cooling system, including: Once high-intensity knock, continuous medium-intensity knock or continuous low-intensity knock is detected, the current engine speed, the density of the fresh air entering the cylinder, the actual water temperature after filtering, the target water temperature, the vehicle speed after filtering and the intake temperature are recorded. When the current engine speed, the density of the fresh air entering the cylinder, the actual water temperature after filtering, the target water temperature, the vehicle speed after filtering and the intake temperature are all the same and the stable time exceeds the preset time T5, it is considered that the operating condition 1 is the same; when the current engine speed, the density of the fresh air entering the cylinder, the actual water temperature after filtering, the target water temperature and the intake temperature are all the same and the stable time exceeds the preset time T5, it is considered that the operating condition 2 is the same; when the current engine speed, the density of the fresh air entering the cylinder and the vehicle speed after filtering are all the same and the stable time exceeds the preset time T5, it is considered that the operating condition 3 is the same; If the number of high-intensity knocks exceeds the preset number and meets working condition 2 but does not meet working condition 1, the average value of the filtered vehicle speed during working condition 2, v, is read. Avg1 , and based on the average value v obtained under high intensity knock Avg1 Updating the preset value D3 and the preset value D4 based on high-intensity knock, wherein the number of high-intensity knock occurrences is reset to zero and then accumulated again after any update of the preset value D3 or the preset value D4; If the number of consecutive medium-intensity knocks exceeds the preset number and meets working condition 2 but does not meet working condition 1, the average value of the filtered vehicle speed during working condition 2 is read v Avg1 , and based on the average value v obtained under continuous medium intensity knock Avg1 Update the preset value D3 and preset value D4 based on continuous moderate intensity knock, wherein the number of continuous moderate intensity knock occurrences is reset to zero and then accumulated again after any update of D3 or D4; If the number of consecutive low-intensity knocks exceeds the preset number and meets working condition 2 but does not meet working condition 1, the average value of the filtered vehicle speed during working condition 2 is read v Avg1 , and based on the average value v under continuous low-intensity knock Avg1 Update the preset value D3 and the preset value D4 based on continuous low-intensity knock, wherein the number of continuous low-intensity knock occurrences is reset to zero and then accumulated again after any update of D3 or D4; If the number of high-intensity knocks exceeds the preset number and meets working condition 3 but does not meet working condition 2, the target water temperature average value T under working condition 3 is read. CoolantDsrdAvg1 , and based on the average value T under high intensity detonation CoolantDsrdAvg1 Updating the preset value D1 and the preset value D2 based on high-intensity knock, wherein the number of high-intensity knock occurrences is reset to zero and then accumulated again after any update of D1 or D2; If the number of consecutive medium-intensity knocks exceeds the preset number and meets working condition 3 but does not meet working condition 2, the target water temperature average value T under working condition 3 is read. CoolantDsrdAvg1 , and based on the target water temperature average value T under continuous medium intensity detonation CoolantDsrdAvg1 Update the preset value D1 and preset value D2 based on continuous moderate intensity knock, wherein the number of continuous moderate intensity knock occurrences is reset to zero and then accumulated again after any update of D1 or D2; If the number of consecutive low-intensity knocks exceeds the preset number and meets working condition 3 but does not meet working condition 2, the target water temperature average value T under working condition 3 is read. CoolantDsrdAvg1 , and based on the target water temperature average value T under continuous low-intensity detonation CoolantDsrdAvg1 Update the preset value D1 and the preset value D2 based on continuous low-intensity knock, wherein the number of continuous low-intensity knock occurrences is reset to zero and then accumulated again after any update of D1 or D2; If when the fan is on, if high-intensity knock, continuous medium-intensity knock and continuous low-intensity knock all occur, and the corresponding cumulative vehicle mileage during engine operation exceeds the preset mileage, the update coefficients of D1, D2, D3 and D4 will be adjusted. Among them, the cumulative vehicle mileage will be cleared immediately after the update coefficients of D1, D2, D3 and D4 increase.

8. The method according to claim 7, characterized in that The average value v obtained under high intensity knock Avg1 Update the preset value D3 and preset value D4 based on high intensity knock, including: if the fan is in the high speed fan on state in working condition 2, then in the subsequent driving cycle, update the actual vehicle speed to be no greater than the average value v of the filtered vehicle speed Avg1 The preset values ​​D3 and D4 under the above conditions are respectively equal to the first multiples of D3 and D4 after the last update; if the fan is in the low-speed fan-on state in working condition 2, then in the subsequent driving cycle, the updated actual vehicle speed is not greater than the average value v of the filtered vehicle speed Avg1 The preset value D4 under the condition is D4, which is equal to the second multiple of D4 after the last update; if the fan is not turned on in working condition 2, the actual vehicle speed is updated in the subsequent driving cycle and is not greater than the average value v of the filtered vehicle speed. Avg1 The preset value D4 under the above condition is D4, where D4 is equal to the third multiple of D4 after the last update, wherein the values ​​of the first multiple, the second multiple and the third multiple decrease in sequence; The average value v obtained under continuous medium intensity knock Avg1 Update the preset value D3 and preset value D4 based on continuous medium intensity knock, including: if the fan is in the high-speed fan on state in working condition 2, then in the subsequent driving cycle, update the actual vehicle speed to be no greater than the average value v of the filtered vehicle speed Avg1 The preset values ​​D3 and D4 under the above conditions are respectively equal to the fourth multiple of D3 and D4 after the last update; if the fan is in the low speed fan on state in working condition 2, then in the subsequent driving cycle, the updated actual vehicle speed is not greater than the average value v of the filtered vehicle speed Avg1 The preset value D4 under the condition is D4, which is equal to the fifth multiple of D4 after the last update; if the fan is not turned on in working condition 2, the actual vehicle speed is updated in the subsequent driving cycle and is not greater than the average value v of the filtered vehicle speed. Avg1 The preset value D4 under the above condition is D4, where D4 is equal to the sixth multiple of D4 after the last update, wherein the values ​​of the fourth multiple, the fifth multiple and the sixth multiple decrease in sequence; The average value v based on continuous low-intensity knock Avg1 Update the preset value D3 and preset value D4 based on continuous low-intensity knock, including: if the fan is in the high-speed fan on state in working condition 2, then in the subsequent driving cycle, the actual vehicle speed is updated to be no greater than the average vehicle speed v after filtering Avg1 The preset values ​​D3 and D4 under the above conditions are respectively equal to the seventh multiple of D3 and D4 after the last update; if the fan is in the low speed fan on state in working condition 2, then in the subsequent driving cycle, the updated actual vehicle speed is not greater than the average vehicle speed v after filtering. Avg1 The preset value D4 under the condition is D4, which is equal to the eighth multiple of D4 after the last update; if the fan is not turned on in working condition 2, the actual vehicle speed is updated in the subsequent driving cycle and is not greater than the average vehicle speed v after filtering. Avg1 The preset value D4 under the above condition is D4, which is equal to the ninth multiple of D4 after the last update, wherein the values ​​of the seventh multiple, the eighth multiple, and the ninth multiple decrease in sequence; Among them, the values ​​of the first multiple, the fourth multiple and the seventh multiple decrease in sequence, the values ​​of the second multiple, the fifth multiple and the eighth multiple decrease in sequence, and the values ​​of the third multiple, the sixth multiple and the ninth multiple decrease in sequence.

9. The method according to claim 8, characterized in that The average value T based on the occurrence of high intensity knock CoolantDsrdAvg1 Update the preset value D1 and preset value D2 based on high intensity knock, including: if the fan is in the high speed fan on state in working condition 3, then in the subsequent driving cycle, the updated target water temperature is not greater than the target water temperature average value T CoolantDsrdAvg1 The preset values ​​D1 and D2 under the above conditions are equal to the tenth multiple of D1 and D2 after the last update respectively; if the fan is in the low speed fan on state in working condition 3, then in the subsequent driving cycle, the updated target water temperature is not greater than the target water temperature average value T CoolantDsrdAvg1 The preset value D2 under the condition is D2, which is equal to the eleventh multiple of D2 after the last update; if the fan is not turned on in working condition 3, the updated target water temperature is not greater than the target water temperature average value T in the subsequent driving cycle. CoolantDsrdAvg1 The preset value D2 under the above condition is D2, which is equal to the twelfth multiple of D2 after the last update, wherein the values ​​of the tenth multiple, the eleventh multiple, and the twelfth multiple decrease in sequence; The target water temperature average value T under continuous medium intensity detonation is CoolantDsrdAvg1 Update the preset value D1 and preset value D2 based on continuous medium intensity knock, including: if the fan is in the high-speed fan on state in working condition 3, then in the subsequent driving cycle, the updated target water temperature is not greater than the target water temperature average value T CoolantDsrdAvg1 The preset values ​​D1 and D2 under the above conditions are equal to the thirteenth multiple of D3 and D4 after the last update respectively; if the fan is in the low speed fan on state in working condition 3, then in the subsequent driving cycle, the updated target water temperature is not greater than the target water temperature average value T CoolantDsrdAvg1 The preset value D2 under the condition is D2, which is equal to the fourteenth multiple of D2 after the last update; if the fan is not turned on in working condition 3, the updated target water temperature is not greater than the target water temperature average value T in the subsequent driving cycle. CoolantDsrdAvg1 The preset value D2 under the above condition is D2, which is equal to the fifteenth multiple of D2 after the last update, wherein the values ​​of the thirteenth multiple, the fourteenth multiple, and the fifteenth multiple decrease in sequence; The target water temperature average value T under continuous low-intensity detonation is CoolantDsrdAvg1 Update the preset value D1 and preset value D2 based on continuous low-intensity knock, including: if the fan is in the high-speed fan on state in working condition 3, then in the subsequent driving cycle, the updated target water temperature is not greater than the target water temperature average value T CoolantDsrdAvg1 The preset values ​​D1 and D2 under the above conditions are equal to the sixteenth multiple of D1 and D2 after the last update respectively; if the fan is in the low speed fan on state in working condition 3, then in the subsequent driving cycle, the updated target water temperature is not greater than the target water temperature average value T CoolantDsrdAvg1 The preset value D2 under the condition is D2, which is equal to the seventeenth multiple of D2 after the last update; if the fan is not turned on in working condition 3, the updated target water temperature is not greater than the target water temperature average value T in the subsequent driving cycle. CoolantDsrdAvg1 The preset value D2 under the above condition is D2, where D2 is equal to the eighteenth multiple of D2 after the last update, wherein the values ​​of the sixteenth multiple, the seventeenth multiple, and the eighteenth multiple decrease in sequence; Among them, the values ​​of the tenth multiple, the thirteenth multiple and the sixteenth multiple decrease in sequence, the values ​​of the eleventh multiple, the fourteenth multiple and the seventeenth multiple decrease in sequence, and the values ​​of the twelfth multiple, the fifteenth multiple and the eighteenth multiple decrease in sequence.

10. The method according to claim 9, characterized in that After the update coefficients of D1, D2, D3, and D4 are updated, they are saved after power is turned off. In the next vehicle driving cycle, the table values ​​determined by the fan control based on water temperature and the fan control based on intake air temperature and vehicle speed will be used. These values ​​will be multiplied by the previously saved update coefficients of D1, D2, D3, and D4 to obtain the final D1, D2, D3, and D4.

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