Fan control method, system, program, device and motor vehicle

Abstract

The application relates to the technical field of fan control, in particular to a fan control method, system, program, device and motor vehicle. First, the target rotating speed, the estimated clutch input rotating speed of the fan after the influence of the rotating speed and the slip rate, and three control modes are intelligently selected according to the clutch input rotating speed: if the target rotating speed is not higher than the rotating speed, the energy-saving disconnection mode is entered; if the target rotating speed is higher than the rotating speed but not higher than the slip-influenced rotating speed, the intelligent closed-loop mode is entered; otherwise, the high-efficiency on-off mode is entered. In the core intelligent closed-loop mode, the method combines the steady-state feedforward control amount based on the target rotating speed, the transient feedforward control amount based on the real-time rotating speed and the change rate, and the feedback control amount generated by the parameter-adjustable adaptive regulator, and the three are combined into the final control instruction. The application realizes fast, accurate and energy-saving control of the fan rotating speed. The problems of slow response, easy oscillation and high energy consumption in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the field of fan control technology, specifically to fan control methods, systems, programs, equipment, and motor vehicles. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] In motor vehicles, the fan is driven by the engine crankshaft, and its speed can be actively adjusted. Adjusting the fan speed is typically achieved by changing the transmission ratio between the fan and the engine crankshaft using a clutch (such as an electronically controlled silicone oil clutch or an electromagnetic clutch), thus enabling precise control of the fan speed.

[0004] In existing technologies, fan response speed is limited by factors such as engine temperature and engine speed, exhibiting varying degrees of delay. Traditional closed-loop fan speed control methods further exacerbate the inherent delay caused by fan characteristics when dealing with transient conditions, and are prone to oscillations when approaching the target speed. They also rely excessively on calibration accuracy, making it difficult to achieve adaptive adjustment under different operating conditions. Summary of the Invention

[0005] This invention provides a fan control method, system, program, device, and vehicle. It constructs a control method that integrates feedforward prediction, adaptive adjustment, delay compensation, and multi-mode coordination to overcome the inherent large inertia and nonlinear characteristics of the fan system. This enables the fan speed to track the target command quickly, accurately, and smoothly, and minimizes the additional energy consumption of the fan operation while meeting the heat dissipation requirements.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of the present invention provides a fan control method, comprising the following steps: Obtain the target speed, the estimated fan speed, and the clutch input speed after the slip ratio is applied; When the target speed is not greater than the estimated speed, the fan is controlled to enter the energy-saving disconnect mode and outputs a control command to disengage the clutch. When the target speed is greater than the estimated speed, but not greater than the clutch input speed after the slip rate is affected, the fan is controlled to enter the intelligent closed-loop mode. When the target speed is greater than the estimated speed and also greater than the clutch input speed after the slip rate is affected, the fan is controlled to enter the high-efficiency on / off mode. In the intelligent closed-loop mode, the current actual speed of the fan and its rate of change are obtained; Based on the target speed, the preset steady-state feedforward mapping table is queried to obtain the steady-state feedforward control quantity r2; The transient feedforward control quantity r1 is determined based on the current actual rotational speed and its rate of change. Based on the current actual speed, its rate of change, and the target speed, the feedback control quantity r0 is calculated through an adaptive regulator with adjustable parameters; The steady-state feedforward control quantity r2, the transient feedforward control quantity r1, and the feedback control quantity r0 are synthesized to obtain the final control command and output it.

[0007] Furthermore, the estimated rotational speed is calculated using the following formula: Nd = N_engine × i_drag; Where Nd is the estimated rotational speed, N_engine is the engine speed, and i_drag is the rotational transmission ratio obtained through bench calibration.

[0008] Furthermore, in intelligent closed-loop mode, the transient feedforward control quantity r1 is determined based on the current actual rotational speed and its rate of change, specifically as follows: Based on the current actual rotational speed n and rotational acceleration dn, the transient feedforward mapping table is queried to obtain the transient feedforward control quantity r1.

[0009] Furthermore, in intelligent closed-loop mode, the feedback control quantity r0 is calculated through a parameter-adjustable adaptive regulator, including the following steps: Calculate the difference Cur between the rotational speed n_delay after the set delay time and the current actual rotational speed n. Query the correction factor mapping table based on the absolute value of the difference Cur to obtain the correction factor fac. The value of the correction factor fac is positively correlated with the absolute value of the difference Cur. By adjusting the proportional parameter Kp_base and the integral parameter Ki_base using the correction factor fac, the adaptive proportional parameter Kp and the adaptive integral parameter Ki are obtained. Based on the deviation between the predicted speed and the target speed, proportional-integral calculations are performed using the adaptive proportional parameter Kp and the adaptive integral parameter Ki to obtain the feedback control quantity r0. Wherein, the predicted rotational speed = n + dn × T_comp, dn is the rotational acceleration, and T_comp is the calibrated delay compensation time.

[0010] Furthermore, the preset steady-state feedforward mapping table is obtained through bench calibration, specifically as follows: In the fan bench system, the fan duty cycle is adjusted by increasing and decreasing the preset step size, and the corresponding steady-state speed is recorded after the speed stabilizes at each duty cycle. A steady-state feedforward mapping table is generated based on the recorded duty cycle-steady-state speed data pairs.

[0011] Furthermore, in the high-efficiency on / off mode, the following controls are executed: Get the actual fan speed; When the actual speed is lower than Nt-Δ, the first duty cycle command is output, which controls the fan to enter on mode; When the actual speed is higher than Nt+Δ, the second duty cycle command is output, which controls the fan to enter off mode; Where Nt is the target speed, Δ is the preset speed hysteresis interval, and the first duty cycle command is greater than the second duty cycle command.

[0012] A second aspect of the present invention provides a fan control system, comprising: The data acquisition module is configured to acquire the target speed, the estimated fan speed, and the clutch input speed after the slip rate is affected. The mode discrimination module is configured to: when the target speed is not greater than the estimated speed, control the fan to enter the energy-saving disconnect mode and output a control command to disengage the clutch; The mode discrimination module is also configured to control the fan to enter the intelligent closed-loop mode when the target speed is greater than the estimated speed and not greater than the clutch input speed after the slip rate is affected. The mode discrimination module is also configured to control the fan to enter the high-efficiency on / off mode when the target speed is greater than the estimated speed and greater than the clutch input speed after the slip rate is affected. In the intelligent closed-loop mode, the current actual speed of the fan and its rate of change are obtained; Based on the target speed, the preset steady-state feedforward mapping table is queried to obtain the steady-state feedforward control quantity r2; The transient feedforward control quantity r1 is determined based on the current actual rotational speed and its rate of change. Based on the current actual speed, its rate of change, and the target speed, the feedback control quantity r0 is calculated through an adaptive regulator with adjustable parameters; The steady-state feedforward control quantity r2, the transient feedforward control quantity r1, and the feedback control quantity r0 are synthesized to obtain the final control command and output it.

[0013] A third aspect of the present invention provides a computer program product including computer-readable instructions that, when executed on an electronic device, cause the electronic device to implement the aforementioned fan control method.

[0014] A fourth aspect of the present invention provides an electronic device including at least one processor and a memory connected to the processor, the memory being used to store a computer program; the processor being used to execute the computer program, enabling the electronic device to implement the fan control method described above.

[0015] A fifth aspect of the present invention provides a motor vehicle, including a vehicle body and a controller, wherein the controller controls the operation of an engine and an electric motor according to the steps in the fan control method described above.

[0016] Compared with existing technologies, one or more of the above technical solutions have the following beneficial effects: 1. By comparing the target speed with two key physical boundaries of the fan system in real time—the estimated input speed affected by the slip rate and the estimated speed following the rotational speed—the control process is divided into three modes. This design enables the control system to deeply understand and proactively match the physical state and energy consumption characteristics of the fan under different operating conditions, achieving precise energy management from a top-level strategy perspective. When the required speed is lower than the "free cooling" capacity, the clutch is automatically disengaged to eliminate additional energy consumption; when the demand is in the high-efficiency drive range, high-precision closed-loop control is activated; when the demand is extremely high, it switches to the most direct full-efficiency drive mode, thus fundamentally solving the contradiction between fast response and low energy consumption that traditional single control modes cannot simultaneously achieve at the system level.

[0017] 2. In intelligent closed-loop mode, a composite control architecture of "steady-state feedforward + transient feedforward + adaptive feedback" is adopted. Steady-state feedforward, based on a precisely calibrated mapping table, provides accurate basic driving quantities, ensuring the system's response speed and steady-state accuracy. Transient feedforward dynamically compensates for the system's nonlinear inertia based on real-time speed and rate of change, significantly improving the tracking capability during transient processes. Adaptive feedback further eliminates residuals quickly and smoothly. The coordinated operation of these three components enables the control system to possess both the speed of feedforward and the robustness of feedback, fundamentally overcoming the inherent defects of traditional PID control in handling large inertia and nonlinear objects, such as slow response and overshoot oscillation.

[0018] 3. The parameters of the adaptive regulator can be dynamically adjusted according to the speed change trend. Specifically, by monitoring the dynamic trend of speed deviation (e.g., calculating the speed difference before and after the delay), the strength of the proportional and integral actions is adjusted online. In transient processes requiring large adjustments, the control action is enhanced to accelerate the response; in steady-state processes approaching the target speed, the control action is weakened to avoid overshoot and oscillation. Through this "variable parameter" strategy, a single regulator is equipped to handle different dynamic processes, reducing steady-state error and improving the system's adaptability under different operating conditions. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0020] Figure 1 This is a schematic diagram of the relationship between fan speed acceleration and friction coefficient provided in one or more embodiments of the present invention; Figure 2 This is a flowchart of fan adaptive optimization control provided by one or more embodiments of the present invention; Figure 3 This is a closed-loop control flowchart provided by one or more embodiments of the present invention. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] As described in the background section, existing technologies achieve precise control of fan speed by changing the transmission ratio between the fan and the engine crankshaft using a clutch. Taking an electronically controlled silicone oil clutch as an example, the working principle is explained as follows: by adjusting the electronic control signal (such as the PWM duty cycle) applied to the silicone oil clutch, the shear force of the silicone oil is changed, thereby controlling the transmission ratio between the fan and the engine crankshaft, and achieving precise control of the fan speed.

[0025] These types of fans have delay characteristics and non-linear drive characteristics, specifically: Delay characteristics: The large mass and high moment of inertia of the fan impeller result in significant mechanical inertial delays during acceleration and deceleration. Furthermore, from the issuance of control commands, the magnetization of the silicone oil clutch, torque transmission, to the change in speed, there are multiple stages of transmission delays, making the entire fan system a typical controlled object with large time delays and high inertia.

[0026] Nonlinear drive characteristics: The relationship between the driving force required by the fan and its rotational speed and acceleration is highly nonlinear. For example... Figure 1 The Stribek curve shown indicates that near the steady-state point where the rotational acceleration is zero, a large torque disturbance is required to overcome static friction and initiate fan acceleration or deceleration; however, once in acceleration or deceleration mode, a small torque change can alter the magnitude of acceleration. This nonlinearity makes it difficult for control systems using fixed parameters to maintain good performance across all operating conditions.

[0027] Existing control methods involve setting a target speed based on state parameters such as engine coolant temperature and vehicle speed, and then using a fixed-parameter PID (proportional-integral-derivative) closed-loop control algorithm to adjust the actual fan speed. This method has revealed several problems in practical applications.

[0028] For example, when a vehicle enters transient conditions such as rapid acceleration or coasting in gear, the engine's thermal load changes rapidly, and the fan speed cannot quickly track the changes in the target command, resulting in large fluctuations in engine temperature.

[0029] In the aforementioned problems, the existing technology uses fixed PID control, which is a pure feedback control. It only begins to operate after a speed deviation occurs. The fan's inherent large delay and inertia cause the deviation signal to be generated slowly, resulting in a significant lag in the controller's response.

[0030] At the same time, existing methods do not take into account the differences in driving force required at different target rotation speeds, and cannot provide effective initial driving force at the moment of target change, which exacerbates the slow start-up caused by inertia.

[0031] Secondly, when approaching the target speed, the fan speed often fluctuates around the set value (oscillation), or there is a long-term static error in steady state, which affects heat dissipation efficiency and NVH (noise, vibration and acoustic roughness).

[0032] In the aforementioned problem, as the fan approaches the target speed, its dynamic characteristics enter the sensitive region of the aforementioned nonlinear curve. A PID controller with fixed parameters cannot adapt to this change; parameters that are too large will cause overshoot and oscillation, while parameters that are too small will lead to slow adjustment and deviation.

[0033] Meanwhile, the control signal needs a delay before it can affect the speed, and the speed feedback also has a delay. The PID output may be based on "outdated" error information, which can easily cause phase lag in a delayed system, eventually leading to continuous oscillation.

[0034] In addition, under certain operating conditions (such as when the target speed is lower than the engine's reverse speed), the fan is still in a closed-loop drive state that consumes energy; or when extremely high speeds are required, the adjustment method is not direct or efficient enough.

[0035] Because existing methods typically employ a single closed-loop control mode, they fail to intelligently switch based on the actual physical working boundaries of the fan clutch (such as whether it has entered the overrunning clutch state or reached the maximum slip ratio), thus causing unnecessary energy loss.

[0036] It is evident that the problems with existing fan control methods are related to the inherent defects of the control methods themselves, as well as the physical characteristics of the fans themselves, which are coupled with and amplified by each other.

[0037] In summary, this solution provides fan control methods, systems, programs, equipment, and vehicles, constructing a four-in-one control architecture of "state perception, feedforward prediction, dynamic adjustment, and boundary protection" to counteract the inherent large inertia, large delay, and nonlinearity of the fan system, ultimately achieving the control objectives of fast transient response, high steady-state accuracy, and optimal energy consumption.

[0038] Referring to the Stribek curve, this scheme uses the magnitude of fan speed acceleration to simulate changes in driving force, such as... Figure 1 As shown, when the fan speed acceleration is 0, when the target speed changes, due to inertia, the fan needs a large driving force to generate acceleration. When the acceleration is large, only a small force is needed to change the fan's acceleration.

[0039] Because different engine models have different crankshaft and fan gear ratios, the corresponding clutch input speeds are inconsistent at the same fan speed. For a specific engine model, bench tests are conducted to pre-calibrate the relationship between the required speed and the required duty cycle under steady-state conditions for different demanding speeds. When different fan speed requirements are input, the feedforward known quantities are obtained to improve steady-state responsiveness and accuracy.

[0040] In this scheme, the relationship between the required speed and the required duty cycle under steady-state conditions is pre-calibrated by using bench tests to obtain the steady-state duty cycle of the fan. The specific process is as follows.

[0041] Experimental preparation: In the test bench system, which includes fans, drive motors, controllers, data acquisition equipment, speed sensors, etc., ensure that other external environmental factors of the test bench are stable.

[0042] Data acquisition and calibration: (1) After determining the fan duty cycle distribution range (10-100%), increase it to 100% in increments of 5%-10%, and run it for about 30 seconds after the duty cycle is adjusted and the speed is relatively stable. Record the actual fan speed under different duty cycles; (2) Perform reverse verification by decreasing the step size from 5% to 10% to ensure data consistency; (3) Save the speed-duty cycle mapping data table and automatically interpolate the intermediate value of the two elements.

[0043] By inputting different fan speeds, the corresponding duty cycle can be obtained from a table.

[0044] To address the issue that traditional closed-loop fan speed control methods are prone to oscillations near the target speed and cannot achieve adaptive adjustment under different operating conditions, this solution introduces a dual-mode adaptive PID method. This method identifies the fan's operating trend through fan speed acceleration. When a significant upward or downward trend in fan speed is detected, the Kp and Ki parameters are dynamically adjusted to accelerate the adjustment, avoiding steady-state fluctuations in fan speed and reducing steady-state error.

[0045] In this scheme, a "significant upward or downward trend" is defined as follows: Fan speed difference = Current speed - Speed ​​after a set delay time. A speed difference greater than a threshold indicates a significant upward trend in fan speed. Conversely, a difference less than the threshold indicates a significant downward trend in fan speed. The threshold and delay time must be calibrated together.

[0046] The mode switching in this solution is as follows: when the fan speed shows a significant upward trend, increase the PI control to reduce the upward speed surge. When the fan speed shows a significant downward trend, increase the PI control in the opposite direction to reduce the downward speed surge.

[0047] The parameter adaptation in this scheme is mainly achieved by adjusting the Kp and Ki parameters. The correction factor is obtained by looking up a table based on the fan speed difference; the larger the absolute value of the speed difference, the larger the correction factor. The smaller the absolute value of the speed difference, the smaller the correction factor, because the speed is relatively stable at this point.

[0048] Due to its physical characteristics and the multiple delay effects inherent in the control loop, fan control is typically considered a system with a large time delay. By using the fan speed acceleration and the current speed to predict the fan speed after a certain period, and incorporating the predicted speed into the fan closed-loop control for delay compensation, future multi-step control inputs are optimized to mitigate the effects of the delay.

[0049] In this scheme, the predicted fan speed = current fan speed + fan speed acceleration. Delay compensation time. The purpose is to calculate the expected fan speed after delay compensation.

[0050] Regarding the delay compensation in this scheme, a common PID controller uses the difference between the actual speed and the set speed as the closed-loop input. The delay-compensated PID controller uses the difference between the predicted speed and the set speed as the closed-loop input, effectively avoiding short-term over-adjustment caused by system response delay.

[0051] Closed-loop control process as follows Figure 3 As shown, it includes the following steps: The output parameters are fan speed n, fan speed acceleration dn (pre-filtered), and delayed fan speed ndelay; Adaptive PID: The difference Cur between the fan speed n and the delayed speed ndelay is obtained. The absolute value of the difference Cur is inversely proportional to the magnitude of the correction factor fac. Based on the correction factor fac and the basic P and I parameters, the final P and I parameters are obtained and input to the PI controller. Combined with delay compensation, the closed-loop duty cycle r0 is obtained. Delay compensation = Predicted speed - Set speed; Steady-state pre-control mode: The fan speed n is calibrated through a pre-conducted bench steady-state experiment to obtain the duty cycle r2 of steady-state pre-control; Transient pre-control mode: The duty cycle r1 of transient pre-control is obtained from the fan speed n and the fan speed acceleration dn; The final fan duty cycle r is obtained by using the closed-loop duty cycle r0, the steady-state pre-control duty cycle r2, and the transient pre-control duty cycle r1.

[0052] The duty cycle r1 of the transient pre-control is pre-calibrated through bench tests. The Stribek curve is used as a reference for calibrating the duty cycle under different speeds and accelerations. The calibration follows the rule that the larger the acceleration, the smaller the duty cycle, and the larger the speed, the larger the duty cycle. This can make the pre-control more accurate and reduce the difficulty of PID adjustment.

[0053] Control process such as Figure 2 As shown.

[0054] Mode 1 (Energy Saving Disconnect Mode): When the target speed (fan set speed) is not greater than the fan speed (i.e., the speed at which the engine drives the fan), the demand is lower than the "free cooling" capacity, so it should be completely disconnected. Therefore, the output duty cycle is 0%, achieving zero additional energy consumption.

[0055] Mode 2 (Intelligent Closed-Loop Mode): When the target speed (fan set speed) is greater than the fan speed, and the fan set speed is not greater than the input speed affected by the slip rate, the demand is higher than the free cooling, but does not exceed the clutch natural slip limit. High-precision intelligent closed-loop control is activated: a control method of transient pre-control + steady-state pre-control + adaptive PID is adopted.

[0056] Mode 3 (High-efficiency on / off mode): When the fan set speed is greater than the fan follow speed and the fan set speed is greater than the input speed after the slip rate is affected, the demand is extremely high and the clutch needs to generate the maximum drive slip. Therefore, the fan switches to the most direct on / off control mode.

[0057] Input speed affected by slip rate = [output speed × (1 - slip rate)].

[0058] Slip rate = [(drive shaft speed - fan speed) / drive shaft speed] × 100%.

[0059] The fan speed following engine rotation refers to the steady-state speed reached by the fan, which is "passively driven" by the engine through the drive belt and residual clutch resistance (such as air shearing and trace amounts of silicone oil drag), when the electronically controlled silicone oil clutch is set to a "fully disengaged" state (i.e., duty cycle = 0%). Since the fan speed following engine rotation is difficult to measure precisely, it is estimated in engineering practice (including this solution). In summary, the fan control method proposed in this solution includes the following steps: Obtain the target speed, the estimated fan speed, and the clutch input speed after the slip ratio is applied; When the target speed is not greater than the estimated speed, the system enters the energy-saving disconnection mode and outputs a control command to disengage the clutch. When the target speed is greater than the estimated speed, but not greater than the clutch input speed after the slip rate is affected, the fan is controlled to enter the intelligent closed-loop mode. When the target speed is greater than the estimated speed and also greater than the clutch input speed after the slip rate is affected, the fan is controlled to enter the high-efficiency on / off mode. In the intelligent closed-loop mode, the current actual speed of the fan and its rate of change are obtained; Based on the target speed, the preset steady-state feedforward mapping table is queried to obtain the steady-state feedforward control quantity r2; The transient feedforward control quantity r1 is determined based on the current actual rotational speed and its rate of change. Based on the current actual speed, its rate of change, and the target speed, the feedback control quantity r0 is calculated through an adaptive regulator with adjustable parameters; The steady-state feedforward control quantity r2, the transient feedforward control quantity r1, and the feedback control quantity r0 are synthesized to obtain the final control command and output it.

[0060] As a further implementation method, the estimated rotational speed is calculated using the following formula: Nd = N_engine × i_drag; Where Nd is the estimated rotational speed, N_engine is the engine speed, and i_drag is the rotational transmission ratio obtained through bench calibration.

[0061] As a further implementation method, in intelligent closed-loop mode, the transient feedforward control quantity r1 is determined based on the current actual rotational speed and its rate of change, specifically as follows: Based on the current actual rotational speed n and rotational acceleration dn, the transient feedforward mapping table is queried to obtain the transient feedforward control quantity r1.

[0062] As a further implementation, in intelligent closed-loop mode, the feedback control quantity r0 is calculated through a parameter-adjustable adaptive regulator, including the following steps: Calculate the difference Cur between the rotational speed n_delay after the set delay time and the current actual rotational speed n. Query the correction factor mapping table based on the absolute value of the difference Cur to obtain the correction factor fac. The value of the correction factor fac is positively correlated with the absolute value of the difference Cur. By adjusting the proportional parameter Kp_base and the integral parameter Ki_base using the correction factor fac, the adaptive proportional parameter Kp and the adaptive integral parameter Ki are obtained. Based on the deviation between the predicted speed and the target speed, proportional-integral calculations are performed using the adaptive proportional parameter Kp and the adaptive integral parameter Ki to obtain the feedback control quantity r0. Wherein, the predicted rotational speed = n + dn × T_comp, dn is the rotational acceleration, and T_comp is the calibrated delay compensation time.

[0063] As a further implementation method, the preset steady-state feedforward mapping table is obtained through a bench calibration method, specifically as follows: In the fan bench system, the fan duty cycle is adjusted by increasing and decreasing the preset step size, and the corresponding steady-state speed is recorded after the speed stabilizes at each duty cycle. A steady-state feedforward mapping table is generated based on the recorded duty cycle-steady-state speed data pairs.

[0064] As a further implementation method, in the high-efficiency on / off mode, the following control is performed: Get the actual fan speed; When the actual rotational speed is lower than Nt-Δ, the first duty cycle command is output; When the actual rotational speed is higher than Nt+Δ, output the second duty cycle command; Where Nt is the target speed, Δ is the preset speed hysteresis interval, and the first duty cycle command is greater than the second duty cycle command.

[0065] This solution divides the control process into three modes by comparing the target speed with two key physical boundaries of the fan system in real time: the estimated input speed after the effect of the slip rate and the estimated speed following the rotational speed. This design enables the control system to deeply understand and proactively match the physical state and energy consumption characteristics of the fan under different operating conditions, achieving precise energy management from a top-level strategy perspective. When the required speed is lower than the "free cooling" capacity, the clutch is automatically disengaged to eliminate additional energy consumption; when the demand is in the high-efficiency drive range, high-precision closed-loop control is activated; when the demand is extremely high, it switches to the most direct full-efficiency drive mode, thus fundamentally solving the contradiction between fast response and low energy consumption that traditional single control modes cannot achieve at the system level.

[0066] In the core intelligent closed-loop mode, a composite control architecture of "steady-state feedforward + transient feedforward + adaptive feedback" is adopted. Steady-state feedforward, based on a precisely calibrated mapping table, provides accurate basic driving quantities, ensuring both the speed and steady-state accuracy of the system response. Transient feedforward dynamically compensates for the nonlinear inertia of the system based on real-time rotational speed and rate of change, significantly improving the tracking capability during transient processes. Adaptive feedback further eliminates residuals quickly and smoothly. The coordinated operation of these three components enables the control system to possess both the speed of feedforward and the robustness of feedback, fundamentally overcoming the inherent defects of traditional PID control in handling large inertia and nonlinear systems, such as slow response and overshoot oscillations.

[0067] The parameters of the adaptive regulator can be dynamically adjusted according to the speed change trend. Specifically, by monitoring the dynamic trend of speed deviation (such as calculating the speed difference before and after the delay), the strength of the proportional and integral actions is adjusted online. In transient processes requiring large adjustments, the control action is enhanced to accelerate the response; in steady-state processes approaching the target speed, the control action is weakened to avoid overshoot and oscillation. Through this "variable parameter" strategy, a single regulator is equipped to cope with different dynamic processes, reducing steady-state error and improving the system's adaptability under different operating conditions.

[0068] Accordingly, a fan control system includes: The data acquisition module is configured to acquire the target speed, the estimated fan speed, and the clutch input speed after the slip rate is affected. The mode discrimination module is configured to: when the target speed is not greater than the estimated speed, enter the energy-saving disconnect mode and output a control command to disconnect the clutch; The mode discrimination module is also configured to control the fan to enter the intelligent closed-loop mode when the target speed is greater than the estimated speed and not greater than the clutch input speed after the slip rate is affected. The mode discrimination module is also configured to control the fan to enter the high-efficiency on / off mode when the target speed is greater than the estimated speed and greater than the clutch input speed after the slip rate is affected. In the intelligent closed-loop mode, the current actual speed of the fan and its rate of change are obtained; Based on the target speed, the preset steady-state feedforward mapping table is queried to obtain the steady-state feedforward control quantity r2; The transient feedforward control quantity r1 is determined based on the current actual rotational speed and its rate of change. Based on the current actual speed, its rate of change, and the target speed, the feedback control quantity r0 is calculated through an adaptive regulator with adjustable parameters; The steady-state feedforward control quantity r2, the transient feedforward control quantity r1, and the feedback control quantity r0 are synthesized to obtain the final control command and output it.

[0069] The control system divides the control process into three modes by comparing the target speed with two key physical boundaries of the fan system in real time: the estimated input speed affected by the slip rate and the speed following the target speed. This design enables the control system to deeply understand and proactively match the physical state and energy consumption characteristics of the fan under different operating conditions, achieving precise energy management from a top-level strategy perspective. When the required speed is lower than the "free cooling" capacity, the clutch is automatically disengaged to eliminate additional energy consumption; when the demand is in the high-efficiency drive range, high-precision closed-loop control is activated; and when the demand is extremely high, it switches to the most direct full-efficiency drive mode, thus fundamentally solving the contradiction between fast response and low energy consumption that traditional single control modes cannot achieve at the system level.

[0070] In intelligent closed-loop mode, a composite control architecture of "steady-state feedforward + transient feedforward + adaptive feedback" is adopted. Steady-state feedforward, based on a precisely calibrated mapping table, provides accurate basic driving quantities, ensuring both the speed and steady-state accuracy of the system response. Transient feedforward dynamically compensates for the nonlinear inertia of the system based on real-time rotational speed and rate of change, significantly improving the tracking capability during transient processes. Adaptive feedback further eliminates residuals quickly and smoothly. The coordinated operation of these three components enables the control system to possess both the speed of feedforward and the robustness of feedback, fundamentally overcoming the inherent defects of traditional PID control in handling large inertia and nonlinear systems, such as slow response and overshoot oscillations.

[0071] Accordingly, a computer program product includes computer-readable instructions that, when executed on an electronic device, cause the electronic device to perform the steps in the aforementioned fan control method, specifically including: Obtain the target speed, the estimated fan speed, and the clutch input speed after the slip ratio is applied; When the target speed is not greater than the estimated speed, the system enters the energy-saving disconnection mode and outputs a control command to disengage the clutch. When the target speed is greater than the estimated speed, but not greater than the clutch input speed after the slip rate is affected, the intelligent closed-loop mode is entered. When the target speed is greater than the estimated speed and also greater than the clutch input speed after the slip rate is affected, the high-efficiency on / off mode is entered. In the intelligent closed-loop mode, the current actual speed of the fan and its rate of change are obtained; Based on the target speed, the preset steady-state feedforward mapping table is queried to obtain the steady-state feedforward control quantity r2; The transient feedforward control quantity r1 is determined based on the current actual rotational speed and its rate of change. Based on the current actual speed, its rate of change, and the target speed, the feedback control quantity r0 is calculated through an adaptive regulator with adjustable parameters; The steady-state feedforward control quantity r2, the transient feedforward control quantity r1, and the feedback control quantity r0 are synthesized to obtain the final control command and output it.

[0072] In the program execution method, the control process is divided into three modes by comparing the target speed with two key physical boundaries of the fan system in real time: the estimated follow-up speed and the input speed after the slip rate. This design enables the control system to deeply understand and actively match the physical state and energy consumption characteristics of the fan under different operating conditions, achieving precise energy consumption management from the top-level strategy.

[0073] When the required speed is lower than the "free cooling" capacity, the clutch is automatically disengaged to eliminate additional energy consumption; when the demand is in the high-efficiency drive range, high-precision closed-loop control is activated; when the demand is extremely high, it switches to the most direct full-effect drive mode, thereby resolving the contradiction between fast response and low energy consumption that the traditional single control mode cannot achieve.

[0074] Accordingly, an electronic device includes at least one processor and a memory connected to the processor, the memory storing a computer program; the processor executes the computer program, enabling the electronic device to implement the steps in the above-described fan control method, specifically including: Obtain the target speed, the estimated fan speed, and the clutch input speed after the slip ratio is applied; When the target speed is not greater than the estimated speed, the system enters the energy-saving disconnection mode and outputs a control command to disengage the clutch. When the target speed is greater than the estimated speed, but not greater than the clutch input speed after the slip rate is affected, the intelligent closed-loop mode is entered. When the target speed is greater than the estimated speed and also greater than the clutch input speed after the slip rate is affected, the high-efficiency on / off mode is entered. In the intelligent closed-loop mode, the current actual speed of the fan and its rate of change are obtained; Based on the target speed, the preset steady-state feedforward mapping table is queried to obtain the steady-state feedforward control quantity r2; The transient feedforward control quantity r1 is determined based on the current actual rotational speed and its rate of change. Based on the current actual speed, its rate of change, and the target speed, the feedback control quantity r0 is calculated through an adaptive regulator with adjustable parameters; The steady-state feedforward control quantity r2, the transient feedforward control quantity r1, and the feedback control quantity r0 are synthesized to obtain the final control command and output it.

[0075] In the method executed by the electronic device, the control process is divided into three modes by comparing the target speed with two key physical boundaries of the fan system in real time: the estimated follow-speed and the input speed affected by slip rate. This design enables the control system to deeply understand and proactively match the physical state and energy consumption characteristics of the fan under different operating conditions, achieving precise energy consumption management from a top-level strategy perspective.

[0076] When the required speed is lower than the "free cooling" capacity, the clutch is automatically disengaged to eliminate additional energy consumption; when the demand is in the high-efficiency drive range, high-precision closed-loop control is activated; when the demand is extremely high, it switches to the most direct full-effect drive mode, thereby resolving the contradiction between fast response and low energy consumption that the traditional single control mode cannot achieve.

[0077] Accordingly, a motor vehicle is provided, which is equipped with at least one controller and a memory connected to the controller. The memory is used to store a computer program; the controller is used to execute the computer program and is capable of implementing the steps in the above-described fan control method, specifically including: Obtain the target speed, the estimated fan speed, and the clutch input speed after the slip ratio is applied; When the target speed is not greater than the estimated speed, the system enters the energy-saving disconnection mode and outputs a control command to disengage the clutch. When the target speed is greater than the estimated speed, but not greater than the clutch input speed after the slip rate is affected, the intelligent closed-loop mode is entered. When the target speed is greater than the estimated speed and also greater than the clutch input speed after the slip rate is affected, the high-efficiency on / off mode is entered. In the intelligent closed-loop mode, the current actual speed of the fan and its rate of change are obtained; Based on the target speed, the preset steady-state feedforward mapping table is queried to obtain the steady-state feedforward control quantity r2; The transient feedforward control quantity r1 is determined based on the current actual rotational speed and its rate of change. Based on the current actual speed, its rate of change, and the target speed, the feedback control quantity r0 is calculated through an adaptive regulator with adjustable parameters; The steady-state feedforward control quantity r2, the transient feedforward control quantity r1, and the feedback control quantity r0 are synthesized to obtain the final control command and output it.

[0078] The controller's execution method divides the control process into three modes by comparing the target speed with two key physical boundaries of the fan system in real time: the estimated follow-speed and the input speed affected by slip rate. This design enables the control system to deeply understand and proactively match the physical state and energy consumption characteristics of the fan under different operating conditions, achieving precise energy management from a top-level strategy perspective.

[0079] When the required speed is lower than the "free cooling" capacity, the clutch is automatically disengaged to eliminate additional energy consumption; when the demand is in the high-efficiency drive range, high-precision closed-loop control is activated; when the demand is extremely high, it switches to the most direct full-effect drive mode, thereby resolving the contradiction between fast response and low energy consumption that the traditional single control mode cannot achieve.

[0080] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A fan control method, characterized in that, Includes the following steps: Obtain the target speed, the estimated fan speed, and the clutch input speed after the slip ratio is applied; When the target speed is not greater than the estimated speed, the fan is controlled to enter the energy-saving disconnect mode and outputs a control command to disengage the clutch. When the target speed is greater than the estimated speed, but not greater than the clutch input speed after the slip rate is affected, the fan is controlled to enter the intelligent closed-loop mode. When the target speed is greater than the estimated speed and also greater than the clutch input speed after the slip rate is affected, the fan is controlled to enter the high-efficiency on / off mode. In the intelligent closed-loop mode, the current actual speed of the fan and its rate of change are obtained; Based on the target speed, the preset steady-state feedforward mapping table is queried to obtain the steady-state feedforward control quantity r2; The transient feedforward control quantity r1 is determined based on the current actual rotational speed and its rate of change. Based on the current actual speed, its rate of change, and the target speed, the feedback control quantity r0 is calculated through an adaptive regulator with adjustable parameters; The steady-state feedforward control quantity r2, the transient feedforward control quantity r1, and the feedback control quantity r0 are synthesized to obtain the final control command and output it.

2. The fan control method as described in claim 1, characterized in that, The estimated rotational speed is calculated using the following formula: Nd = N_engine × i_drag; Where Nd is the estimated rotational speed, N_engine is the engine speed, and i_drag is the rotational transmission ratio obtained through bench calibration.

3. The fan control method as described in claim 1, characterized in that, In intelligent closed-loop mode, the transient feedforward control quantity r1 is determined based on the current actual speed and its rate of change, specifically as follows: Based on the current actual rotational speed n and rotational acceleration dn, the transient feedforward mapping table is queried to obtain the transient feedforward control quantity r1.

4. The fan control method as described in claim 1, characterized in that, In intelligent closed-loop mode, the feedback control quantity r0 is calculated through a parameter-adjustable adaptive regulator, including the following steps: Calculate the difference Cur between the rotational speed n_delay after the set delay time and the current actual rotational speed n. Query the correction factor mapping table based on the absolute value of the difference Cur to obtain the correction factor fac. The value of the correction factor fac is positively correlated with the absolute value of the difference Cur. By adjusting the proportional parameter Kp_base and the integral parameter Ki_base using the correction factor fac, the adaptive proportional parameter Kp and the adaptive integral parameter Ki are obtained. Based on the deviation between the predicted speed and the target speed, proportional-integral calculations are performed using the adaptive proportional parameter Kp and the adaptive integral parameter Ki to obtain the feedback control quantity r0. Wherein, the predicted rotational speed = n + dn × T_comp, dn is the rotational acceleration, and T_comp is the calibrated delay compensation time.

5. A fan control method as described in claim 1, characterized in that, The preset steady-state feedforward mapping table is obtained through bench calibration, specifically as follows: In the fan bench system, the fan duty cycle is adjusted by increasing and decreasing the preset step size, and the corresponding steady-state speed is recorded after the speed stabilizes at each duty cycle. A steady-state feedforward mapping table is generated based on the recorded duty cycle-steady-state speed data pairs.

6. The fan control method as described in claim 1, characterized in that, In high-efficiency on / off mode, the following control is executed: Get the actual fan speed; When the actual rotational speed is lower than Nt-Δ, the first duty cycle command is output; When the actual rotational speed is higher than Nt+Δ, output the second duty cycle command; Where Nt is the target speed, Δ is the preset speed hysteresis interval, and the first duty cycle command is greater than the second duty cycle command.

7. A fan control system, characterized in that, include: The data acquisition module is configured to acquire the target speed, the estimated fan speed, and the clutch input speed after the slip rate is affected. The mode discrimination module is configured to: when the target speed is not greater than the estimated speed, control the fan to enter the energy-saving disconnect mode and output a control command to disengage the clutch; The mode discrimination module is also configured to control the fan to enter the intelligent closed-loop mode when the target speed is greater than the estimated speed and not greater than the clutch input speed after the slip rate is affected. The mode discrimination module is also configured to control the fan to enter the high-efficiency on / off mode when the target speed is greater than the estimated speed and greater than the clutch input speed after the slip rate is affected. In the intelligent closed-loop mode, the current actual speed of the fan and its rate of change are obtained; Based on the target speed, the preset steady-state feedforward mapping table is queried to obtain the steady-state feedforward control quantity r2; The transient feedforward control quantity r1 is determined based on the current actual rotational speed and its rate of change. Based on the current actual speed, its rate of change, and the target speed, the feedback control quantity r0 is calculated through an adaptive regulator with adjustable parameters; The steady-state feedforward control quantity r2, the transient feedforward control quantity r1, and the feedback control quantity r0 are synthesized to obtain the final control command and output it.

8. A computer program product, characterized in that, Includes computer-readable instructions that, when executed on an electronic device, cause the electronic device to perform the steps in the fan control method of claim 1.

9. An electronic device, characterized in that, It includes at least one processor and a memory connected to the processor, the memory being used to store a computer program; the processor is used to execute the computer program, enabling the electronic device to perform the steps in the fan control method as described in claim 1.

10. A motor vehicle, characterized in that, It includes a vehicle body and a controller, the controller performing the steps of the fan control method of claim 1.

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