Fan control method, device, equipment, product and vehicle

Abstract

The invention provides a fan control method, device, equipment and product and a vehicle, and relates to the technical field of vehicles. After the vehicle enters an off-road working condition, the change rate of the fan rotating speed, the actual rotating speed of an engine and the actual rotating speed of the fan are monitored; determining a target PID correction coefficient based on the actual rotating speed of the engine, the actual rotating speed of the fan and the target rotating speed of the fan determined based on the thermal management requirement of the vehicle, adjusting the change rate of the rotating speed of the fan based on the target PID correction coefficient, and when it is monitored that the change rate of the rotating speed of the fan is larger than a preset change rate of the rotating speed of the fan after adjustment. The actual rotation speed of the engine is controlled to be reduced, control over the rotation speed change rate of the fan is achieved, failure conditions such as fan breakage caused by sudden rotation speed change are avoided, in addition, the rotation speed change rate of the fan is controlled through PID adjustment, and power loss or mechanical loss caused by direct change of the actual rotation speed of the engine can be avoided.

Description

Technical Field

[0001] The present application relates to the technical field of vehicles, and particularly to a fan control method, device, equipment, product and vehicle. Background Art

[0002] An electronically controlled silicone oil fan is installed on the front end gear train of an engine and driven by the engine gear train. In an electronically controlled silicone oil fan, by adjusting the opening degree of the oil inlet valve, the oil filling or oil discharging process of the working area, i.e., the working chamber of the silicone oil clutch, can be controlled, and further, by changing the oil filling amount of the silicone oil in the working chamber, the rotation speed of the electronically controlled silicone oil fan can be adjusted.

[0003] When a vehicle travels in a desert environment, especially when traveling at a high speed to try to cross sand dunes or other complex terrains, the adhesion may be weakened or even lost. For example, when one or more driving wheels of the vehicle are lifted off the ground, or when the tire presses on unstable sand, the vehicle loses adhesion and cannot obtain sufficient traction.

[0004] At this time, the mechanical energy output by the vehicle engine cannot be consumed and will be converted into the rotational kinetic energy of the wheels, resulting in an instantaneous increase in the engine speed. The engine cooling system needs to respond to a higher water temperature request, and the electronically controlled silicone oil fan will be driven by the engine to a high speed or even a fully engaged state to enhance the heat dissipation effect. Among them, the fully engaged state refers to the state where the maximum torque transmission efficiency is achieved between the electronically controlled silicone oil fan and its drive shaft. This state usually occurs when the engine requires the maximum cooling effect, and in this state, the rotation speed of the fan reaches the maximum rotation speed of the fan. However, the excessive rotation speed may exceed the design limit of the fan and its connecting components, resulting in the fracture of the fan blades or the damage of the fan gear train bracket, causing the fan to fail, and even damaging the whole vehicle structure, resulting in greater losses. Summary of the Invention

[0005] Based on the defects and deficiencies of the above-mentioned prior art, the present application provides a fan control method, device, equipment, product and vehicle, which can control the reduction of the fan speed change rate by reducing the engine speed when the fan speed change rate cannot be effectively reduced by adjusting the proportional integral derivative (PID) correction coefficient, so as to avoid the problem that the fan speed suddenly changes, resulting in the damage of the fan blades or the gear train bracket and causing the fan to fail.

[0006] According to the first aspect of the embodiments of the present application, a fan control method is provided. The method includes: after the vehicle enters the off-road working condition, monitoring the fan speed change rate, the actual engine speed and the actual fan speed; determining a target PID correction coefficient based on the actual engine speed, the actual fan speed and the target fan speed, and adjusting the fan speed change rate based on the target PID correction coefficient; if the adjusted fan speed change rate is greater than the preset fan speed change rate, controlling the actual engine speed to decrease so as to reduce the fan speed change rate.

[0007] According to the second aspect of the embodiments of the present application, a fan control device is provided. The device includes:

[0008] A monitoring module, configured to monitor the fan speed change rate, the actual engine speed and the actual fan speed after the vehicle enters the off-road working condition;

[0009] A first control module, configured to determine a target PID correction coefficient based on the actual engine speed, the actual fan speed and the target fan speed, and adjust the fan speed change rate based on the target PID correction coefficient;

[0010] A second control module, configured to control the actual engine speed to decrease so as to reduce the fan speed change rate if the adjusted fan speed change rate is greater than the preset fan speed change rate.

[0011] According to the third aspect of the embodiments of the present application, an electronic device is provided, including a memory and a processor;

[0012] The memory is connected to the processor and is used for storing programs;

[0013] The processor is configured to implement the fan control method as described in the first aspect by running the programs in the memory.

[0014] According to the fourth aspect of the embodiments of the present application, a storage medium is provided. A computer program is stored on the storage medium, and when the computer program is run by a processor, the fan control method as described in the first aspect is implemented.

[0015] According to the fifth aspect of the embodiments of the present application, a computer program product is provided. The computer program product includes computer program instructions, and when the computer program instructions are run by a processor, the processor is caused to execute the fan control method as described in the first aspect.

[0016] According to the sixth aspect of the embodiments of the present application, a vehicle is provided. An electronic control unit and a fan are provided in the vehicle. The electronic control unit is connected to the fan through a fan control wire harness and is configured to control the fan according to the fan control method as described in the first aspect.

[0017] In the above-mentioned fan control method, device, equipment, product and vehicle, after the vehicle enters the off-road working condition, the change rate of the fan speed, the actual engine speed and the actual fan speed can be monitored. Based on the actual engine speed, the actual fan speed and the target fan speed, the target PID correction coefficient can be determined and the change rate of the fan speed can be adjusted based on the target PID correction coefficient. When the change rate of the fan speed is greater than the preset fan speed change rate after adjustment, the actual engine speed can be controlled to decrease, so as to reduce the change rate of the fan speed. In this way, when the change rate of the fan speed cannot be controlled by PID adjustment, that is, when the change rate of the fan speed is greater than the preset fan speed change rate after PID adjustment, the change rate of the fan speed can be reduced by downshifting, that is, controlling the engine speed to decrease, which can avoid the rapid increase of the fan speed or even reaching too high a speed exceeding the design limit of the fan and its connecting components, resulting in the fracture of the fan blade or the damage of the fan gear system bracket, causing the failure of the fan or even the damage of the whole vehicle structure and causing great losses. In addition, by first controlling the change rate of the fan speed through PID adjustment and then adjusting the change rate of the fan speed by controlling the engine speed when the change rate of the fan speed is greater than the preset fan speed change rate after PID adjustment, the power loss and mechanical loss caused by directly controlling the decrease of the actual engine speed can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0019] Figure 1 It is a schematic diagram of the architecture of an engine system given in the embodiment of the present application;

[0020] Figure 2 It is a schematic diagram of the structure of a fan clutch given in the embodiment of the present application;

[0021] Figure 3 It is a schematic diagram of the speed regulation response of an electronically controlled silicone oil fan given in the embodiment of the present application;

[0022] Figure 4 It is a schematic diagram of the flow of a fan control method given in the embodiment of the present application;

[0023] Figure 5 It is a schematic diagram of the change trend of a PID correction coefficient proposed in the embodiment of the present application;

[0024] Figure 6 It is a schematic diagram of a fan control process proposed in the embodiment of the present application;

[0025] Figure 7 This is a schematic structural diagram of a fan control device proposed in an embodiment of the present application;

[0026] Figure 8 This is a schematic structural diagram of an electronic device proposed in an embodiment of the present application. Specific embodiments

[0027] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0028] Overview

[0029] As described in the background art, when a vehicle travels in a desert environment, especially when traveling at a high speed in an attempt to cross sand dunes or other complex terrains, the adhesion may weaken or even disappear. For example, when one or more driving wheels of the vehicle are lifted off the ground, or when the tires press on unstable sand, the vehicle loses adhesion and cannot obtain sufficient traction. At this time, the mechanical energy output by the vehicle's engine cannot be consumed and will be converted into the rotational kinetic energy of the wheels, resulting in an instantaneous increase in the engine speed. For example, it accelerates from 1500 rpm to over 6000 rpm within 1 s. The engine cooling system needs to respond to a high water temperature request, and the electronically controlled silicone oil fan will be activated to the fully engaged state and driven by the engine to a high speed to enhance the heat dissipation effect. However, too high a speed or too rapid a speed change may exceed the design limits of the fan and its connecting components, resulting in the fracture of the fan blades or damage to the fan gear train bracket, causing the fan to fail, and even damaging the entire vehicle structure and causing significant losses.

[0030] On this basis, the inventor further found through research that a relatively high engine speed may drive the fan speed to quickly change to a relatively high value. The change in the engine speed results in different vehicle thermal management requirements. For different thermal management requirements, it is necessary to control the fan to operate at different speeds for heat dissipation to meet the vehicle's thermal management needs. After the vehicle enters the off-road working condition, the fan speed change rate, the actual engine speed, and the actual fan speed are monitored. Based on the actual engine speed, the actual fan speed, and the target fan speed, the target PID correction coefficient is determined, and the fan speed change rate is adjusted based on the target PID correction coefficient. When the adjusted fan speed change rate is greater than the fan speed change rate, the engine is downshifted, that is, the engine speed is mechanically adjusted to effectively reduce the fan speed change rate, achieve effective control of the fan speed change rate, and avoid the fan speed from rising rapidly or even reaching an excessive speed beyond the fan limit, resulting in damage to the fan structure and losses. In addition, since reducing the engine speed involves mechanical adjustment, first, the PID adjustment is used to control the fan speed change rate. When the fan speed change rate is greater than the preset fan speed change rate after the PID adjustment, the engine speed is controlled to adjust the fan speed change rate, which can avoid power loss and mechanical wear caused by directly controlling the reduction of the actual engine speed.

[0031] Based on the above concept, an embodiment of this specification provides a fan control method, which will be described exemplarily below with reference to the accompanying drawings.

[0032] Exemplary scenario

[0033] Reference Figure 1 , Figure 1 is a schematic diagram of the architecture of the engine system, which is a feasible application scenario for the fan control method.

[0034] As Figure 1 shown, taking the electronically controlled silicone oil clutch fan as an example, the engine system includes an electronically controlled silicone oil clutch fan, a fan gear train, a fan control wire harness, an engine electronic control unit (ECU), an engine body, an engine crankshaft, a belt, etc. Among them, the electronically controlled silicone oil clutch fan is fixed to a dedicated gear train or shares the water pump gear train.

[0035] The electronically controlled silicone oil clutch fan is installed on the engine body through the fan gear train and rotates with the engine crankshaft pulley through the belt. That is to say, the electronically controlled silicone oil clutch fan is directly driven by the engine crankshaft pulley. The engine ECU is connected to the electronically controlled silicone oil clutch fan through the fan control wire harness and is used to control the fan speed.

[0036] Among them, the structure of the electronically controlled silicone oil clutch fan can be as Figure 2As shown in the figure, the electronically controlled silicone oil clutch fan includes a driving shaft, a coil assembly, a clutch rear cover, a clutch front cover, a valve plate, a driving plate, a valve rod assembly, a stop seat, a bearing, a working chamber and a storage chamber.

[0037] The electronically controlled silicone oil clutch fan is installed on a pulley through the driving shaft. The coil assembly is installed on the driving shaft through a built-in bearing. The clutch rear cover is connected to the driving shaft through a bearing. The clutch rear cover and the clutch front cover are fixed together by bolts. The driving plate is rigidly connected to the driving shaft through a spline. The clutch rear cover, the clutch front cover and the driving plate have a labyrinth groove structure intersecting with each other in the working chamber and have a certain gap. When the driving shaft rotates, the silicone oil in this gap will be cut. Since the silicone oil has a certain viscosity, torque can be generated when cutting the silicone oil, driving the front and rear covers of the clutch to rotate following the driving plate, and then driving the fan blades installed on the clutch front cover through bolts to rotate.

[0038] When the vehicle is powered on and the engine starts, according to the thermal management requirements of the vehicle, when it is required that the fan rotates at a high speed, the engine ECU sends a pulse width modulation (PWM) signal to the coil assembly through the fan control wire harness to adjust the fan speed. The coil assembly generates different Lorentz forces under different PWM signal voltages and acts on the valve rod assembly. The valve rod assembly moves back and forth axially under the constraint of the stop seat, driving the valve plate to act and adjust the opening of the valve plate, forming path A. Under the action of centrifugal force, the silicone oil in the storage chamber enters the working chamber through path A, that is, the labyrinth groove area formed by the driving plate, the clutch rear cover and the clutch front cover. The silicone oil in this area is cut to form a driving force, driving the clutch rear cover and the clutch front cover to rotate following the driving plate. After the silicone oil passes through the working chamber under the action of centrifugal force, it is introduced into path B by the oil return structure and returns to the storage chamber from path B, forming a cycle. Among them, the opening of the valve plate determines the amount of silicone oil in the working chamber and the driving torque of the clutch, and further determines the fan speed. When, according to the thermal management requirements of the vehicle, the fan speed is not required, that is, there is no requirement for the fan speed, the engine ECU sends a pulse width modulation signal to the coil assembly through the fan control wire harness. The valve plate does not act, forming a normally closed structure with the driving plate, and path A is blocked. Therefore, the silicone oil cannot enter the working chamber, and the silicone oil in the working chamber is introduced into path B and discharged from the working chamber under the action of the oil return structure. Since as much silicone oil as possible is taken out of the working chamber, the fan maintains the lowest idle speed.

[0039] Among them, different from the linear stepless speed regulation of the electric fan according to the PWM signal, the speed regulation of the electronically controlled silicone oil fan is non-linear. The duty cycle of the PWM signal (which can be understood as the fan duty cycle) has little influence on the regulation of the fan speed. The value of the duty cycle of the PWM signal (i.e., the effective PWM signal duty cycle) that can effectively affect the regulation of the fan speed is usually about 30%-50%.

[0040] In addition, both the oil filling and oil draining of the working chamber of the electronically controlled silicone oil clutch fan require a certain amount of time. The specific duration required is related to the input speed of the fan. Both the speed increase and decrease adjustments of the fan require a response time. The input speed of the fan is the rotational speed of the driving member when the engine rotates to drive the motor of the fan to rotate and then drive the driving member of the fan to rotate. As the engine speed changes, the input speed of the fan will change accordingly. As the input speed of the fan changes, the fan speed, that is, the rotational speed of the fan blades, will also change accordingly.

[0041] Exemplarily, at a certain input speed, the speed regulation response of the electronically controlled silicone oil clutch fan can be as Figure 3 shown. The time required for the working chamber of the electronically controlled silicone oil clutch fan to fill and drain oil at a certain input speed is characterized by the response of the fan speed. It can be seen that the working chamber fills with oil relatively quickly and the oil filling time is relatively short. After the duty cycle is adjusted from 0% to 100%, the fan speed rises rapidly and is basically close to a linear rise; the working chamber drains oil relatively slowly and the oil draining time is relatively long. After the duty cycle is adjusted from 100% to 0%, the fan speed does not decrease significantly for a period of time. When it drops to a certain value, the fan speed approaches a linear rapid decrease, which is mainly due to the oil return structure and the relatively small slip of full engagement, resulting in a relatively small oil return pressure.

[0042] In addition, a Hall sensor is integrated in the coil assembly of the electronically controlled silicone oil clutch fan. The Hall sensor is used to detect the actual speed of the fan and send a pulse signal representing the actual speed of the fan to the engine ECU through the fan control wire harness.

[0043] In Figure 1 the engine system shown, the engine ECU further automatically adjusts the fan speed change rate by comparing the actual engine speed, the actual fan speed and the target fan speed. Among them, the adjustment method is the PID adjustment method based on feedback adjustment. After PID adjustment, when the fan speed change rate is greater than the preset fan speed change rate, a shift operation is performed to reduce the fan speed change rate, so as to avoid the situation of fan speed mutation leading to failure.

[0044] Exemplary method

[0045] Please refer to Figure 4 , in an exemplary embodiment, a fan control method is provided, which is applied to, for example, Figure 1 the engine system shown. The engine ECU in the engine system is used to execute this fan control method to control the fan speed change rate. As Figure 4 shown, the fan control method includes steps S401 - S403:

[0046] S401: After the vehicle enters the off-road working condition, monitor the fan speed change rate, the actual engine speed, and the actual fan speed.

[0047] Among them, the actual fan speed can be obtained by real-time detection through a Hall sensor set in the coil assembly of the fan.

[0048] In addition, the actual engine speed can be obtained by real-time detection through a sensor set on the engine.

[0049] The engine ECU obtains the actual fan speed and the actual engine speed, and calculates the fan speed change rate based on the actual fan speed obtained within a period of time.

[0050] Exemplarily, the engine ECU calculates based on the actual fan speed obtained in real time and the actual fan speed obtained at the previous moment to obtain the fan speed change rate.

[0051] Specifically, the engine ECU determines whether the vehicle enters the off-road working condition through a variety of sensors and input signals. For example, after the driver controls the vehicle to enter the off-road mode by rotating the mode switch handle or operating the mode selection button, the engine ECU receives the mode switch / selection signal and determines that the vehicle enters the off-road working condition; based on the sensor data, it judges the road condition of the vehicle and determines that the vehicle enters the off-road working condition based on the road condition; based on the driver's operations on the accelerator and brake pedals, it determines that the vehicle enters the off-road working condition.

[0052] Among them, the off-road mode is a driving mode of the vehicle, which can help the vehicle drive better under complex and rough road conditions, that is, the off-road working condition. The off-road mode mainly plays a role by adjusting vehicle performance parameters, such as increasing torque, optimizing the suspension, adjusting the differential, etc. The off-road mode may include a variety of driving modes, such as snow mode, sand mode, mud mode, rock mode, etc., to meet the needs of different off-road working conditions. Generally, the off-road mode also has functions such as anti-skid function and downhill assist function. That is to say, the off-road mode is suitable for the vehicle to drive on complex terrains such as grasslands, gravel roads, dirt roads, unpaved roads or snow-covered roads (under off-road working conditions). Under these road conditions, the off-road mode can significantly improve the vehicle's passability, stability and off-road ability.

[0053] It can be understood that not only in the off-road working condition, but also in other driving modes of the vehicle except the off-road working condition, this fan control method can be used to control the fan speed change rate.

[0054] S402: Based on the actual engine speed, the actual fan speed, and the fan target speed, determine the target PID correction coefficient, and adjust the fan speed change rate based on the target PID correction coefficient.

[0055] Specifically, the target fan speed is determined based on the thermal management requirements of the vehicle.

[0056] Since the speed regulation of the fan is mainly used to control the heat dissipation effect of the fan to control the engine temperature, the thermal management requirements of the vehicle here mainly refer to the thermal management requirements of the engine. Of course, based on different actual requirements, the thermal management requirements of components such as the transmission, turbocharger, and battery are also within the scope of consideration, that is, the target fan speed is determined based on the thermal management requirements of the engine and even components such as the transmission, turbocharger, and battery.

[0057] Since there is a correlation between the fan duty ratio and the fan speed, ideally, there is a linear correlation between the fan duty ratio and the fan speed. For example, when the fan duty ratio is 50%, the fan speed is half of the maximum fan speed. Therefore, the actual fan duty ratio can be determined based on the actual fan speed.

[0058] Specifically, when adjusting the fan speed change rate based on the target PID correction coefficient, the corresponding actual fan duty ratio is determined based on the actual fan speed, and the actual fan duty ratio is adjusted based on the target PID correction coefficient to adjust the fan speed change rate. It can be understood that since the change in the actual fan duty ratio will cause a change in the fan speed, the fan speed can be adjusted by controlling the actual fan duty ratio, thereby realizing the adjustment of the fan speed change rate.

[0059] Among them, the greater the gap between the adjusted fan duty ratio and the actual fan duty ratio, the higher the fan speed change rate, and the smaller the gap between the adjusted fan duty ratio and the actual fan duty ratio, the lower the fan speed change rate.

[0060] Exemplarily, taking the target PID correction coefficient K p as an example, according to u(t)=K p e(t)+u0(t). Wherein, e(t) is the deviation between the preset fan duty ratio and the actual fan duty ratio, and u0(t) is the actual fan duty ratio.

[0061] S403: If the fan speed change rate is greater than the preset fan speed change rate after adjustment, control the actual engine speed to decrease to reduce the fan speed change rate.

[0062] Among them, the preset fan speed change rate can be determined based on the vehicle boundary and the fan mechanical strength. The vehicle boundary refers to the performance limitations in vehicle design, including constraint conditions in aspects such as the power system, thermal management system, and mechanical structure. Within the vehicle boundary, all components including the fan need to work within a safe and reliable range. Specifically, the preset fan speed change rate is the maximum speed change rate that the fan can withstand, or the preset fan speed change rate is slightly less than the maximum speed change rate that the fan can withstand.

[0063] Exemplarily, the preset fan speed change rate threshold is 2000 rpm / s.

[0064] Since the engine is used to drive the fan, when the actual engine speed is controlled to decrease, the power directly driving the fan weakens, and the fan speed change rate decreases.

[0065] Specifically, after adjusting the fan speed change rate based on the target PID correction coefficient, it is determined whether the adjusted fan speed change rate is greater than the preset fan speed. If the fan speed change rate is greater than the preset fan speed change rate after adjustment, an engine downshift operation is performed to reduce the engine speed through mechanical operation, thereby reducing the fan speed change rate. Among them, the downshift operation is to reduce at least one speed gear.

[0066] Correspondingly, if the fan speed change rate is not greater than the preset fan speed change rate after adjustment, steps S401 and S402 are continued to be executed to prevent the fan speed change rate from increasing until the vehicle exits the off-road working condition, such as the whole vehicle shuts down and stops driving. Or, if the fan speed change rate is not greater than the preset fan speed change rate after adjustment, the process ends, that is, steps S401 - S403 are no longer executed, and the matching between the actual fan speed and the target fan speed is re-verified, and the duty ratio of the fan is dynamically adjusted according to the thermal management requirements.

[0067] Specifically, after the downshift operation, steps S401 - S403 are no longer executed. After that, the matching between the actual fan speed and the target fan speed is re-verified, that is, it is determined whether the target fan speed meets the current thermal management requirements. If it meets, the actual fan speed is adjusted to the target fan speed. If it does not meet, the target fan speed is re-determined according to the thermal management requirements to dynamically adjust the duty ratio of the fan.

[0068] Based on different actual requirements, before executing step S402, the fan speed change rate can be judged first. If the fan speed change rate is not greater than the preset fan speed change rate, step S402 is executed to adjust the fan speed change rate through PID adjustment; if the fan speed change rate is greater than the preset fan speed change rate, step S403 is executed to reduce the fan speed change rate by controlling the engine speed to downshift.

[0069] In addition, the downshift operation can be an automatic downshift realized under the control of the engine ECU, or a downshift prompt can be issued to remind the driver to manually operate to reduce the engine speed gear, that is, the downshift prompt is used to remind the driver to reduce the engine speed gear.

[0070] In addition, since reducing the engine speed involves mechanical adjustment, the rate of change of the fan speed is first controlled by PID adjustment. When the rate of change of the fan speed after PID adjustment is greater than the preset rate of change of the fan speed, the engine speed is then controlled to adjust the rate of change of the fan speed, which can avoid power loss and mechanical wear caused by directly controlling the reduction of the actual engine speed, ensure that the engine provides sufficient power for vehicle driving, and extend the service life of the relevant control components of the engine.

[0071] In this embodiment, after the vehicle enters the off-road working condition, based on the fan target speed, the actually monitored fan actual speed, the engine actual speed, and the fan target speed, the target PID correction coefficient is determined, and the rate of change of the fan speed is adjusted in advance based on the target PID correction coefficient to avoid sudden changes in the fan speed. When the rate of change of the fan speed after adjustment is greater than the preset rate of change of the fan speed, the engine speed is directly reduced, thereby reducing the gearbox gear to increase the moment of inertia, reducing the sudden change rate of the fan input speed, and further reducing the rate of change of the fan speed to avoid sudden changes in the fan speed, so as to avoid failure situations such as fan breakage caused by too fast or too high fan speed changes.

[0072] In order to quickly determine the target PID correction coefficient, in some embodiments, when determining the target PID correction parameter based on the engine actual speed, the fan actual speed, and the fan target speed, based on the differences between the engine actual speed, the fan actual speed, and the fan target speed, the associated PID correction coefficient is determined as the target PID correction coefficient.

[0073] Specifically, first, the difference between the engine actual speed and the fan actual speed is determined as the first difference, and the difference between the engine actual speed and the fan target speed is determined as the second difference. Then, the PID correction coefficient associated with the first difference and the second difference is determined as the target PID correction coefficient.

[0074] That is, there is an association relationship between the first difference, the second difference, and the PID correction coefficient.

[0075] Exemplarily, the first difference is determined according to X = enginespd - acfanspd. Wherein, X represents the first difference, enginespd represents the engine actual speed, and acfanspd represents the fan actual speed. The first difference is determined according to Y = enginespd - tgfanspd. Wherein, Y represents the second difference, enginespd represents the engine actual speed, and tgfanspd represents the fan target speed.

[0076] More specifically, the association relationship can be a one-to-one correspondence relationship. At this time, there is a corresponding relationship among the first difference, the second difference, and the PID correction coefficient. In this corresponding relationship, the first difference, the second difference, and the PID correction coefficient correspond to each other one by one. After determining the first difference and the second difference, based on the corresponding relationship among the first difference, the second difference, and the PID correction coefficient, the PID correction coefficient corresponding to the first difference and the second difference is determined as the target PID correction coefficient.

[0077] Exemplarily, taking the PID correction coefficient as K p as an example, the corresponding relationship among the first difference, the second difference, and the PID correction coefficient can be shown in Table 1 below. For example, when both the first difference and the second difference are 100, the corresponding PID correction coefficient K p = 15.

[0078] Alternatively, more specifically, the association relationship can be a functional relationship, and the functional relationship is used to describe the mapping relationship between variables. At this time, the association relationship among the first difference, the second difference, and the PID correction coefficient can be characterized by a functional relationship formula. After determining the first difference and the second difference, the first difference and the second difference are input into the functional relationship formula, and the output of the functional relationship formula is determined as the target PID correction coefficient.

[0079] Table 1

[0080]

[0081] Among them, the functional relationship formula can be obtained by performing smoothing processing, such as moving weighted average, interpolation, etc., on the corresponding target PID correction coefficients obtained by testing different first differences and second differences, and the different first differences and second differences, so as to ensure the smoothness when performing PID adjustment based on the PID correction coefficient, avoid the step jump of the target PID correction coefficient, and ensure the smoothness of PID adjustment.

[0082] Exemplarily, the functional relationship formula can be obtained by performing smoothing processing on the corresponding relationship among the first difference, the second difference, and the PID correction coefficient shown in Table 1. The PID correction coefficients corresponding to each first difference and second difference in the functional relationship formula can be as Figure 5 shown, where the X-axis represents the value of the first difference, the Y-axis represents the value of the second difference, and the Z-axis represents the value of the PID correction coefficient.

[0083] It should also be noted that the variation law of the PID correction coefficient in the above corresponding relationship or functional relationship formula can be determined based on Figure 3 the speed regulation response of the electronically controlled silicone oil clutch fan shown.

[0084] In this embodiment, based on the differences between the target fan speed and the monitored actual engine speed and actual fan speed, that is, the first difference and the second difference, the PID correction coefficients associated with the first difference and the second difference are used as the target PID correction coefficients. Based on the correlation between the first difference and the second difference, the target PID correction coefficients that meet the current working conditions can be quickly determined, realizing precise adjustment of the fan speed change rate, ensuring that the actual fan speed changes to the target fan speed at a reasonable change rate, and avoiding fan failure.

[0085] In order to determine reasonable target PID correction coefficients, in some embodiments, when determining the PID correction coefficients associated with the first difference and the second difference as the target PID correction coefficients, the four-quadrant control method is used to determine the target PID correction coefficients.

[0086] Specifically, first, based on whether the first difference and the second difference exceed the preset values, the first function, the second function, the third function, or the fourth function is determined as the target function. Then, the first difference and the second difference are input into the target function to obtain the target PID correction coefficients.

[0087] Among them, the first function represents the correlation between the first difference, the second difference, and the PID correction coefficient when both the first difference and the second difference exceed the preset values. The second function represents the correlation between the first difference, the second difference, and the PID correction coefficient when the first difference exceeds the preset value and the second difference does not exceed the preset value. The third function represents the correlation between the first difference, the second difference, and the PID correction coefficient when both the first difference and the second difference do not exceed the preset values. The fourth function represents the correlation between the first difference, the second difference, and the PID correction coefficient when the first difference does not exceed the preset value and the second difference exceeds the preset value.

[0088] That is to say, when both the first difference and the second difference exceed the preset values, the first function is determined as the target function, and then the first difference and the second difference are input into the first function to obtain the target PID correction coefficients. When the first difference exceeds the preset value and the second difference does not exceed the preset value, the second function is determined as the target function, and then the first difference and the second difference are input into the second function to obtain the target PID correction coefficients. When both the first difference and the second difference do not exceed the preset values, the third function is determined as the target function, and then the first difference and the second difference are input into the third function to obtain the target PID correction coefficients. When the first difference does not exceed the preset value and the second difference exceeds the preset value, the fourth function is determined as the target function, and then the first difference and the second difference are input into the fourth function to obtain the target PID correction coefficients.

[0089] Generally, when both the first difference and the second difference exceed a preset value, it is the first quadrant; when the first difference exceeds the preset value and the second difference does not exceed the preset value, it is the second quadrant; when both the first difference and the second difference do not exceed the preset value, it is the third quadrant; when the first difference does not exceed the preset value and the second difference exceeds the preset value, it is the fourth quadrant.

[0090] Exemplarily, the preset value is 0, that is, the first, second, third, and fourth quadrants are divided based on X = 0 and Y = 0. Here, X represents the first difference, and Y represents the second difference.

[0091] Based on different actual requirements, the preset value includes a first preset value and a second preset value, corresponding to the first difference and the second difference respectively. The first, second, third, and fourth quadrants are divided based on whether the first difference exceeds its corresponding first preset value and whether the second difference exceeds its corresponding second preset value.

[0092] More specifically, based on different actual requirements, the PID correction coefficient includes a proportional correction coefficient K p , an integral correction coefficient K i and / or a differential correction coefficient K d . Among them, K p is mainly used for adjustment according to the deviation to accelerate the dynamic response; K i is mainly used for accumulating the deviation to eliminate the steady-state error and improve the stability of the adjustment; K d is mainly used for adjustment according to the change rate of the error to suppress overshoot and oscillation and reduce the adjustment time.

[0093] Exemplarily, the PID correction coefficients corresponding to the first quadrant and the third quadrant are K p , the PID correction coefficient corresponding to the second quadrant is K i , and the PID correction coefficient corresponding to the fourth quadrant is K p . Or, the PID correction coefficients corresponding to the four quadrants are all K p . Of course, based on different actual requirements, the PID correction coefficient corresponding to any quadrant includes at least two of K p and K i and K d , or the PID correction coefficient corresponding to any quadrant includes the three items of K p and K i and K d .

[0094] Exemplarily, taking the preset value as 0 as an example, in the first quadrant, both the first difference and the second difference are greater than 0. The first quadrant represents that the actual engine speed > the actual fan speed, and the actual engine speed > the target fan speed. That is to say, both the actual fan speed and the target fan speed are less than the actual engine speed. At this time, the deviation between the two is small, and the system stability is high. Using K p to adjust the fan speed change rate, the actual fan speed can be quickly adjusted to the target fan speed. The fan speed change rate will not be too high and can accelerate the dynamic response, reducing the steady-state error.

[0095] In the second quadrant, the first difference is greater than 0 and the second difference is less than 0. The second quadrant represents that the target fan speed > the actual engine speed > the actual fan speed. The actual fan speed is insufficient, and the heat dissipation performance does not meet the standard. Using Ki to adjust the fan speed change rate can effectively improve the fan driving force, increase the fan speed change rate, and ensure that the actual fan speed can quickly approach the target fan speed.

[0096] In the third quadrant, both the first difference and the second difference are less than 0. The third quadrant represents that the actual engine speed < the actual fan speed, and the actual engine speed < the target fan speed. That is to say, both the actual fan speed and the target fan speed are greater than the actual engine speed. At this time, the deviation between the two is small, and the system stability is high. Using K p to adjust the fan speed change rate, the actual fan speed can be quickly adjusted to the target fan speed. The fan speed change rate will not be too high and can accelerate the dynamic response, reducing the steady-state error.

[0097] In the fourth quadrant, the first difference is less than 0 and the second difference is greater than 0. The second quadrant represents that the target fan speed < the actual engine speed < the actual fan speed. At this time, the fan speed overshoot may cause the silicone oil clutch to fail to disengage. When the engine speed suddenly changes, it drives the fan close to full coupling, leading to mechanical failure. Using K p to adjust the fan speed change rate, the actual fan speed can be quickly adjusted to the target fan speed, which can accelerate the dynamic response, effectively reduce the silicone oil clutch filling amount, shorten the separation response time, and suppress the fan speed increase.

[0098] In this embodiment, based on whether the first and second differences exceed the preset value, the function representing the correlation relationship between the first difference, the second difference, and the PID correction coefficient in different situations is determined as the target function, and the first difference and the second difference are input into the target function to obtain the target PID correction coefficient, achieving the effect of determining the target PID correction coefficient using different functions for different situations, thereby ensuring the rationality of the determined target PID correction coefficient.

[0099] In order to determine a reasonable target PID correction coefficient, in some embodiments, the value ranges of the PID correction coefficients corresponding to different functions are restricted, and for the first difference and the second difference in different quadrants, corresponding functions are used within their corresponding value ranges of the PID correction coefficients to determine a reasonable target PID correction coefficient to meet the control requirements for the fan speed.

[0100] The value range of the PID correction coefficient corresponding to the first function is the first value range, the value range of the PID correction coefficient corresponding to the second function is the second value range, the value range of the PID correction coefficient corresponding to the third function is the third value range, and the value range of the PID correction coefficient corresponding to the fourth function is the fourth value range.

[0101] Among them, the upper limits of the first value range and the third value range are less than the upper limits of the second value range and the fourth value range, and the lower limits of the first value range and the third value range are less than the lower limit of the second value range belonging to the fourth value range.

[0102] Among them, the first value range and the third value range can be the same or different, but when they are different, the difference between them is small. Similarly, the second value range and the fourth value range can be the same or different, but when they are different, the difference between them is small.

[0103] Exemplarily, the first value range and the third value range are [0, 25], and the second value range and the fourth value range are [10, 40].

[0104] Exemplarily, the first value range is [0, 25], the second value range is [15, 35], the third value range is [0, 20], and the fourth value range is [10, 40].

[0105] It can be understood that for the first quadrant and the third quadrant, that is, the case where both the first difference and the second difference are positive or both are negative, the difference between the actual fan speed and the target fan speed is small. At this time, adjusting the fan speed change rate with the PID correction coefficient within a smaller value range can obtain a better adjustment effect. For the second quadrant and the fourth quadrant, that is, the case where one of the first difference and the second difference is positive and the other is negative, the difference between the actual fan speed and the target fan speed is large. At this time, adjusting the fan speed change rate with the PID correction coefficient within a larger value range can better increase the fan speed to meet the heat dissipation requirements, or better suppress the increase in the fan speed to avoid fan fracture and failure.

[0106] Exemplarily, the change trends of the PID correction coefficients corresponding to different first differences and second differences in the four quadrants can be as described above Figure 5 as shown.

[0107] Exemplarily, the fan control process can be as follows Figure 6 shown. After the whole vehicle is awakened and powered on, when entering the off-road working condition, the four-quadrant control method is used, and the PID correction coefficient is used to adjust the fan duty ratio. After the adjustment, it is judged whether the fan speed change rate ≥ B holds, where B is the preset fan speed change rate threshold. If the fan speed change rate < B, the process ends. If the fan speed change rate ≥ B holds, a downshift operation is performed on the engine, and the fan duty ratio remains the current duty ratio and the process ends.

[0108] In this embodiment, the upper limit of the value range of the PID correction coefficient corresponding to the first function and the third function is set lower than the upper limit of the value range of the PID correction coefficient corresponding to the second function and the fourth function, and the lower limit of the value range of the PID correction coefficient corresponding to the PID function corresponding to the first function and the third function is higher than the lower limit of the value range of the PID correction coefficient corresponding to the second function and the fourth function. In this way, for the first difference and the second difference in different quadrants, corresponding functions can be used to determine a reasonable target PID correction coefficient within the value range of its corresponding PID correction coefficient to meet the control requirements of the fan speed.

[0109] In order to ensure that the power demand of the vehicle can be met while controlling the reduction of the fan speed change rate, in some embodiments, when controlling the actual engine speed to decrease, the actual engine speed is downshifted to the engine target speed.

[0110] Among them, the engine target speed is higher than the engine preset speed, and the engine preset speed is determined based on the power demand of the vehicle.

[0111] Exemplarily, the engine preset speed is 5000 rpm, 5500 rpm or 6000 rpm.

[0112] Specifically, the engine target speed is determined based on the engine preset speed, a control command is generated based on the engine target speed, and the actual engine speed is controlled to decrease to the engine target speed based on this control command. Among them, the control command includes the engine target speed and is used to control the actual engine speed to decrease to the engine target speed.

[0113] Exemplarily, after the engine target speed is determined, the engine target speed is the speed in the first gear of the engine, and the actual engine speed is the speed in the second gear of the engine. Based on the gear difference between the actual engine speed and the engine target speed, a control command is generated, and this control command is used to control the engine speed to decrease by one gear, that is, to control the actual engine speed to decrease from the second gear to the first gear.

[0114] In this embodiment, when the fan speed change rate exceeds the preset fan speed change rate, the actual engine speed is controlled to downshift to an engine target speed higher than the preset engine speed determined based on the power demand of the vehicle. Thus, while meeting the power demand of the vehicle, the engine speed is downshifted to adjust the fan speed change rate and effectively reduce the fan speed change rate.

[0115] To effectively reduce the fan speed change rate, in some embodiments, first determine the change rate difference between the fan speed change rate and the preset fan speed change rate, and then control the engine speed gear to downshift according to the target downshift quantity corresponding to the change rate difference.

[0116] Specifically, after determining the change rate difference, based on the corresponding relationship between the change rate difference and the downshift quantity, the downshift quantity corresponding to the change rate difference is determined as the target downshift quantity, and the engine speed gear is controlled to decrease according to the target downshift quantity.

[0117] Among them, the target downshift quantity is generally 1.

[0118] When controlling the engine speed gear to decrease according to the target downshift quantity, control the engine speed to directly decrease by the number of speed gears of the target downshift quantity, or control the engine speed gear to decrease multiple times until it decreases by the number of speed gears of the target downshift quantity.

[0119] Exemplarily, if the target downshift quantity is 2, when controlling the engine speed gear to decrease, control the engine speed gear to directly decrease by 2 speed gears, or first control the engine speed to decrease by 1 speed gear and then control the engine speed to decrease by 1 speed gear after a certain time interval.

[0120] Generally, the target downshift quantity is usually 1, and the change of the engine speed gear is usually from the second gear to the first gear.

[0121] Specifically, the target downshift quantity can refer to the maximum downshift quantity or the minimum downshift quantity.

[0122] It can be understood that after downshifting, by increasing the rotational inertia of the transmission system (such as adjusting the flywheel or clutch), the impact on the fan caused by the sudden change of the engine speed can be effectively suppressed.

[0123] In this embodiment, based on the change rate difference between the fan speed change rate and the preset fan speed change rate, according to the corresponding target downshift quantity, the engine speed is controlled to decrease, so as to reduce a reasonable number of speed gears based on the degree to which the fan speed change rate is higher than the preset fan speed change rate, realize the dynamic stepped downshift of the fan speed change rate, balance the power demand and heat dissipation protection, effectively reduce the fan speed change rate, and avoid the fan failure caused by too high fan speed change rate.

[0124] In some embodiments, key parameters such as water temperature and oil temperature are continuously monitored to ensure that the PID coefficient correction and downshift operation do not affect the overall vehicle heat dissipation efficiency.

[0125] Specifically, sensors can be used to monitor the water temperature, oil temperature, etc. Among them, the water temperature refers to the temperature of the coolant in the system, and the oil temperature mainly refers to the temperature of the lubricating oil inside the engine. In addition, when monitoring the overall vehicle heat dissipation efficiency, the key parameters that need to be continuously monitored also include flow rate, pressure difference, ambient temperature, etc.

[0126] If all key parameters are normal, that is, all key parameters have been within their corresponding preset value ranges, it can be determined that neither the PID coefficient correction nor the downshift operation affects the overall vehicle heat dissipation efficiency. If there is a certain key parameter that is abnormal, that is, the value of a certain key parameter is not within its corresponding preset value range, it can be determined that the PID coefficient correction or the downshift operation affects the overall vehicle heat dissipation efficiency.

[0127] Specifically, if during the PID coefficient correction process, it is monitored that the value of a certain key parameter is not within its corresponding preset value range, it is determined that the PID coefficient correction affects the overall vehicle heat dissipation efficiency; if during the downshift operation process, it is monitored that the value of a certain key parameter is not within its corresponding preset value range, it is determined that the downshift operation affects the overall vehicle heat dissipation efficiency.

[0128] Correspondingly, after it is monitored that a certain key parameter is affected, a heat dissipation fault prompt is issued to prompt the vehicle to take corresponding measures to ensure the vehicle heat dissipation performance. For example, the engine system is controlled to timely adjust the fan speed or engine speed to ensure the heat dissipation performance.

[0129] In this way, when performing PID coefficient correction or downshift operation to ensure a low fan speed change rate and avoid fan breakage and failure, the heat dissipation performance is monitored, so as to timely detect whether the heat dissipation performance is affected and take corresponding measures in time after the heat dissipation performance is affected to avoid losses.

[0130] Exemplary device

[0131] As Figure 7 shown, an embodiment of the present application also provides a fan control device, including a monitoring module 701, a first control module 702, and a second control module 703.

[0132] Among them,

[0133] The monitoring module 701 is configured to monitor the fan speed change rate, the actual engine speed, and the actual fan speed after the vehicle enters the off-road working condition;

[0134] The first control module 702 is configured to determine a target PID correction coefficient based on the actual engine speed, the actual fan speed, and the target fan speed, and adjust the fan speed change rate based on the target PID correction coefficient;

[0135] The second control module 703 is configured to, if the adjusted fan speed change rate is greater than a preset fan speed change rate, control the actual engine speed to decrease so as to decrease the fan speed change rate.

[0136] The fan control device provided in this embodiment belongs to the same inventive concept as the fan control method provided in the above embodiments of the present application, and can execute the method provided in any of the above embodiments of the present application, and has corresponding functional modules and beneficial effects for executing the method. For technical details not described in detail in this embodiment, reference may be made to the specific processing content of the fan control method provided in the above embodiments of the present application, which will not be elaborated here.

[0137] The functions implemented by the above monitoring module 701, first control module 702, and second control module 703 can be respectively implemented in the form of software called by the same or different processors, which is not limited in the embodiments of the present application.

[0138] Exemplary electronic device

[0139] Another embodiment of the present application further proposes an electronic device, as shown in Figure 8 The electronic device includes: a memory 800 and a processor 810.

[0140] Wherein, the memory 800 is connected to the processor 810 and is used for storing programs;

[0141] The processor 810 is configured to implement the fan control method disclosed in any of the above embodiments by running the program stored in the memory 800.

[0142] Specifically, the electronic device may further include: a bus, a communication interface 820, an input device 830, and an output device 840.

[0143] The processor 810, the memory 800, the communication interface 820, the input device 830, and the output device 840 are interconnected through the bus. Among them:

[0144] The bus may include a path for transmitting information between various components of the computer system.

[0145] The processor 810 may be a general-purpose processor, such as a general-purpose central processing unit (CPU), a microprocessor, etc., or an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the solution of the present application. It may also be a digital signal processor (DSP), an ASIC, a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0146] The processor 810 may include a main processor, and may also include a baseband chip, a modem, etc.

[0147] The memory 800 stores the program for implementing the technical solution of the present application, and may also store an operating system and other key services. Specifically, the program may include program code, and the program code includes computer operation instructions. More specifically, the memory 800 may include a read-only memory (ROM), other types of static storage devices that can store static information and instructions, a random access memory (RAM), other types of dynamic storage devices that can store information and instructions, a disk memory, a flash memory, etc.

[0148] The input device 830 may include a device for receiving data and information input by a user, such as a keyboard, a mouse, a camera, a scanner, a light pen, a voice input device, a touch screen, a pedometer, or a gravity sensor, etc.

[0149] The output device 840 may include a device for allowing information to be output to a user, such as a display screen, a printer, a speaker, etc.

[0150] The communication interface 820 may include a device of any transceiver type for communicating with other devices or communication networks, such as Ethernet, a radio access network (RAN), a wireless local area network (WLAN), etc.

[0151] The processor 810 executes the program stored in the memory 800 and calls other devices, and can be used to implement each step of any one of the fan control methods provided in the above embodiments of the present application.

[0152] Those skilled in the art can understand, Figure 8The structure shown is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the electronic device to which the solution of this application is applied. The specific electronic device may include more or fewer components than those shown in the figure, or combine some components, or have a different component layout.

[0153] An embodiment of this application also provides a chip, which includes a processor and a data interface. The processor reads and runs a program stored on a memory through the data interface to execute the fan control method introduced in any of the above embodiments. The specific processing process and its beneficial effects can be seen in the embodiment introduction of the above fan control method.

[0154] An embodiment of this application also provides a vehicle, in which an electronic control unit and a fan are provided, and the electronic control unit is used to execute the steps in the above fan control method.

[0155] In addition to the above methods and devices, an embodiment of this application provides a computer program product, which includes computer program instructions. When the computer program instructions are run by a processor, the processor is caused to execute the steps in the fan control method according to various embodiments of this application described in the "Exemplary Method" section above in this specification.

[0156] The computer program product can be written in any combination of one or more programming languages to write program code for performing the operations of the embodiments of this application. The programming languages include object-oriented programming languages such as Java, C++, etc., and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code can be executed completely on the user computing device, partially on the user device, executed as an independent software package, partially on the user computing device and partially on a remote computing device, or completely executed on a remote computing device or server.

[0157] In addition, an embodiment of this application also provides a storage medium, on which a computer program is stored, and the computer program is executed by a processor to execute the steps in the fan control method according to various embodiments of this application described in the "Exemplary Method" section above in this specification.

[0158] The basic principles of the present invention have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, benefits, effects, etc. mentioned in the present invention are only examples and not limitations. It cannot be considered that these advantages, benefits, effects, etc. are essential for each embodiment of the present invention. In addition, the above disclosed specific details are only for the purposes of illustration and easy understanding, rather than limitations. The above details do not limit the present invention to necessarily adopt the above specific details to implement.

[0159] The block diagrams of the devices, apparatuses, equipment, and systems involved in the present invention are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "comprising," "including," "having," etc. are open-ended terms, meaning "including but not limited to," and can be used interchangeably with each other. The words "or" and "and" used herein refer to the phrase "and / or" and can be used interchangeably with it, unless the context clearly indicates otherwise. The phrase "such as" used herein refers to the phrase "such as but not limited to" and can be used interchangeably with it.

[0160] It should also be noted that in the devices, equipment, and methods of the present invention, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent solutions of the present invention.

[0161] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present invention. Therefore, the present invention is not intended to be limited to the aspects shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

[0162] It should be understood that the qualifiers "first," "second," "third," "fourth," "fifth," and "sixth" used in the description of the embodiments of the present invention are only for more clearly elaborating the technical solutions and cannot be used to limit the protection scope of the present invention.

[0163] The above description has been given for purposes of illustration and description. In addition, this description is not intended to limit the embodiments of the present invention to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions, and sub-combinations thereof.

Claims

1. A fan control method, characterized in that: The method comprises: After the vehicle enters off-road conditions, the fan speed change rate, actual engine speed and actual fan speed are monitored; Determining a target PID correction coefficient based on the actual engine speed, the actual fan speed and a target fan speed, and adjusting the fan speed change rate based on the target PID correction coefficient; If the fan speed change rate is greater than the preset fan speed change rate after adjustment, the actual engine speed is controlled to decrease so as to reduce the fan speed change rate.

2. The fan control method according to claim 1, characterized in that: The determining of the target PID correction coefficient based on the actual engine speed, the actual fan speed and the target fan speed includes: Determine the difference between the actual speed of the engine and the actual speed of the fan as a first difference, and determine the difference between the actual speed of the engine and the target speed of the fan as a second difference; A PID correction coefficient associated with the first difference and the second difference is determined as the target PID correction coefficient.

3. The fan control method according to claim 2, characterized in that: The step of determining the PID correction coefficient associated with the first difference and the second difference as the target PID correction coefficient includes: Determining the first function, the second function, the third function or the fourth function as the target function based on whether the first difference and the second difference exceed a preset value; Inputting the first difference and the second difference into the objective function to obtain the target PID correction coefficient; Among them, the first function represents the correlation between the first difference, the second difference and the PID correction coefficient when the first difference and the second difference both exceed the preset value; the second function represents the correlation between the first difference, the second difference and the PID correction coefficient when the first difference exceeds the preset value and the second difference does not exceed the preset value; the third function represents the correlation between the first difference, the second difference and the PID correction coefficient when the first difference and the second difference both do not exceed the preset value; the fourth function represents the correlation between the first difference, the second difference and the PID correction coefficient when the first difference does not exceed the preset value and the second difference exceeds the preset value.

4. The fan control method according to claim 3, characterized in that: The value range of the PID correction coefficient corresponding to the first function is the first value range; the value range of the PID correction coefficient corresponding to the second function is the second value range; the value range of the PID correction coefficient corresponding to the third function is the third value range; the value range of the PID correction coefficient corresponding to the fourth function is the fourth value range; Among them, the upper limits of the first value range and the third value range are smaller than the upper limits of the second value range and the fourth value range; the lower limits of the first value range and the third value range are smaller than the lower limits of the second value range and the fourth value range.

5. The fan control method according to claim 1, characterized in that: The controlling the actual engine speed to decrease includes: The actual engine speed is controlled to be downshifted to a target engine speed, where the target engine speed is higher than a preset engine speed, and the preset engine speed is determined based on a power demand of the vehicle.

6. The fan control method according to claim 1, characterized in that: The controlling the actual engine speed to decrease includes: Determining a change rate difference between the fan speed change rate and the preset fan speed change rate; The engine speed gear is controlled to downshift according to the target downshift amount corresponding to the change rate difference.

7. A fan control device, characterized in that: The device comprises: The monitoring module is used to monitor the fan speed change rate, the actual engine speed and the actual fan speed after the vehicle enters off-road conditions; a first control module, configured to determine a target PID correction coefficient based on the actual engine speed, the actual fan speed and a target fan speed, and adjust the fan speed change rate based on the target PID correction coefficient; The second control module is used to control the actual engine speed to decrease so as to decrease the fan speed change rate if the fan speed change rate is greater than a preset fan speed change rate after adjustment.

8. An electronic device, characterized in that: including memory and processor; The memory is connected to the processor and is used to store programs; The processor is used to implement the fan control method according to any one of claims 1 to 6 by running the program in the memory.

9. A computer program product, characterized in that The computer program product comprises computer program instructions, which, when executed by a processor, enable the processor to execute the fan control method according to any one of claims 1 to 6.

10. A vehicle, characterized in that: The vehicle is provided with an electronic control unit and a fan, and the electronic control unit is connected to the fan via a fan control harness, and is used to control the fan according to the fan control method according to any one of claims 1 to 6 above.

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