A vehicle thermal protection control method and system

Abstract

This application relates to the field of thermal protection control technology, and discloses a vehicle thermal protection control method and system. The method includes: acquiring real-time vehicle speed and real-time engine speed, and calculating a first value; determining the power transmission state; when in a connected state, dynamically setting an overheat protection speed range, the upper limit threshold of which is dynamically adjusted according to the first value and the radiator water channel on / off state; when the real-time speed falls into this range and the duration exceeds a first time, executing a first control; acquiring the switching valve position and thermostat state, determining the radiator water channel state, and dynamically adjusting the opening temperature threshold when the thermostat is closed; when the radiator water channel is in a blocked state and the pre-opening trigger condition is met, executing a pre-opening operation. This invention can improve the adaptability and response accuracy of thermal protection.

Description

Technical Field

[0001] This application relates to the field of thermal protection control technology, and in particular to a vehicle thermal protection control method and system. Background Technology

[0002] Effective vehicle heat management is an important technical means to improve vehicle performance and self-protection. For example, when a vehicle is cold-started, the thermostat actively disconnects the engine from the external radiator, allowing the coolant to circulate only within the engine, thus helping the engine quickly and efficiently reach its ideal operating temperature and reducing engine wear and fuel consumption. When the vehicle overheats, the thermostat opens, ensuring that the coolant flows through the radiator in a large circulation to dissipate heat, preventing situations such as engine torque limiting and air conditioning shutdown when the engine is running at high speeds and high torque, which could affect driving safety.

[0003] Although thermostats can perform basic cycle switching based on temperature, existing thermal protection control strategies still have the following limitations: existing vehicle thermal protection control methods are mostly based on fixed speed or temperature thresholds for judgment, without fully considering the impact of engine load, changes in heat dissipation capacity, and the structural state of the cooling system on overheating risk. Especially in vehicles with manual transmissions, changes in the ratio of engine speed to vehicle speed can reflect the actual load of the engine, and the on / off state of the radiator water passages directly affects the heat dissipation capacity. Existing technologies are difficult to adaptively adjust based on these dynamic factors, which can easily lead to untimely response or false triggering of protection strategies, and cannot effectively balance engine safety and power performance.

[0004] Therefore, the present invention provides a vehicle thermal protection control method and system. Summary of the Invention

[0005] This application provides a vehicle thermal protection control method and system to improve the adaptability and response accuracy of thermal protection.

[0006] In a first aspect, this application provides a vehicle thermal protection control method, the method comprising: Step S1: Obtain the real-time vehicle speed and the real-time engine speed of the vehicle, and divide the real-time engine speed by the real-time vehicle speed to obtain the first real-time value. Step S2: Determine the power transmission status. When the power transmission status is connected, dynamically set the overheat protection speed range. The overheat protection speed range includes an upper threshold and a lower threshold. The lower threshold is a preset reference speed, and the upper threshold is dynamically adjusted according to the first value and the on / off status of the radiator water channel. Step S3: When the real-time speed falls within the overheat protection speed range and the duration exceeds the first duration, execute the first control. Step S4: Obtain the position of the switching valve and the status of the thermostat. Determine the status of the radiator water channel based on the position of the switching valve and the status of the thermostat. When the thermostat is in the closed state, dynamically adjust the opening temperature threshold. Step S5: When the radiator water channel is detected to be blocked and the preset pre-opening trigger condition is met, the pre-opening operation is performed.

[0007] In conjunction with the first aspect, in the first implementation of the first aspect of this application, dynamically adjusting the upper limit threshold based on the first value and the on / off state of the radiator water channels includes: Preset a basic upper limit value and a benchmark value, calculate the difference between the benchmark value and the first value, and calculate the first correction coefficient based on the difference; The second correction factor is determined based on the open / closed state of the radiator water passages. When the radiator water passages are in the open state, the second correction factor is set to 1. When the radiator water passages are in the closed state, the second correction factor is determined based on the degree of loss of engine cooling capacity caused by the radiator water passage closure. The upper limit value is obtained by multiplying the basic upper limit value by the first correction factor, and then by the second correction factor.

[0008] In conjunction with the first aspect, in the second implementation of the first aspect of this application, after step S5, the following steps are included: After the pre-start operation is executed, the real-time speed is continuously acquired. If the real-time speed is still within the overheat protection speed range and the first control is in the stopped state, the first control is executed. If the real-time speed is not within the overheat protection speed range and the first control is still being executed, the first control is stopped.

[0009] In conjunction with the first aspect, in the third implementation of the first aspect of this application, the first control includes: The engine calculates the rate of increase of the real-time engine speed. When the rate of increase is greater than a preset emergency rate threshold, the engine's ignition system is controlled to not perform ignition operation in at least one working cycle. When the rate of increase is less than or equal to the emergency rate threshold, the amount of fuel supplied to the combustion chamber is reduced.

[0010] In conjunction with the first aspect, in the fourth implementation of the first aspect of this application, adjusting the activation temperature threshold according to the first value includes: The system presets a base opening temperature value, a reference value, and a logarithmic adjustment coefficient. It then calculates the ratio of the current first value to the reference value, performs a logarithmic transformation on the ratio to obtain a deviation index, multiplies the deviation index by the logarithmic adjustment coefficient, and adds 1 to obtain a temperature correction coefficient. Finally, it multiplies the base opening temperature value by the temperature correction coefficient to obtain the adjusted opening temperature threshold.

[0011] In conjunction with the first aspect, in the fifth implementation of the first aspect of this application, the pre-activation triggering conditions include: The real-time rotational speed is greater than the preset pre-activation trigger speed threshold, and the rate of increase of the real-time rotational speed is greater than the preset increase threshold.

[0012] In conjunction with the first aspect, in the sixth implementation of the first aspect of this application, the step of setting the pre-activation trigger speed threshold includes: The system presets the base and start-up speed values ​​and reference values. Based on the comparison between the current first value and the reference value, it calculates the venting correction coefficient using the piecewise linear difference method. It then multiplies the base and start-up speed values ​​by the venting correction coefficient to obtain the initial pre-start-up trigger speed threshold. It checks whether the first control is being executed. If so, it multiplies the initial pre-start-up trigger speed threshold by the preset coefficient to obtain the final pre-start-up trigger speed threshold. Otherwise, it uses the initial pre-start-up trigger speed threshold as the final pre-start-up trigger speed threshold.

[0013] In conjunction with the first aspect, in the fifth implementation of the first aspect of this application, the pre-activation triggering condition also includes: The clutch is disengaged and the real-time rotational speed is greater than a preset threshold.

[0014] In conjunction with the first aspect, in the fifth implementation of the first aspect of this application, the pre-activation triggering condition also includes: The thermostat is closed, and the coolant temperature is higher than the adjusted opening temperature threshold.

[0015] Secondly, this application provides a vehicle thermal protection control system, the system comprising: The parameter calculation unit is used to obtain the real-time vehicle speed and the real-time engine speed of the vehicle, and divide the real-time engine speed by the real-time vehicle speed to obtain the first real-time value. The interval setting unit is used to determine the power transmission status. When the power transmission status is connected, the overheat protection speed range is dynamically set. The overheat protection speed range includes an upper limit threshold and a lower limit threshold. The lower limit threshold is a preset reference speed, and the upper limit threshold is dynamically adjusted according to the first value and the on / off status of the radiator water channel. The overheat control unit is used to monitor the real-time speed. When the real-time speed falls within the overheat protection speed range and the duration exceeds the first duration, the first control is executed. The threshold adjustment unit is used to obtain the position of the switching valve and the status of the thermostat, and to determine the status of the radiator water channel based on the position of the switching valve and the status of the thermostat. When the thermostat is in the closed state, the opening temperature threshold is dynamically adjusted. The activation control unit is used to perform a pre-activation operation when the radiator water channel is detected to be blocked and the preset pre-activation trigger conditions are met.

[0016] Compared with the prior art, the beneficial effects of the present invention are at least as follows: The technical solution provided in this application introduces the ratio of engine speed to vehicle speed as a load characterization parameter, and dynamically sets the overheat protection speed range by combining the power transmission state and the on / off state of the radiator water channels. This makes the overheat judgment more in line with the actual working conditions and improves the accuracy and adaptability of thermal protection. By dynamically adjusting the thermostat opening temperature threshold, an adaptive response to the heat dissipation demand under different loads can be achieved. By introducing a pre-opening mechanism, intervention can be carried out in advance before the cooling system pressure rises, avoiding damage to the cooling system caused by excessive pressure and improving safety and reliability. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of one embodiment of a vehicle thermal protection control method according to the present application. Figure 2 This is a schematic diagram of one embodiment of a vehicle thermal protection control system according to the present application. Detailed Implementation

[0019] This application provides a vehicle thermal protection control method and system. The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein. Furthermore, the terms "comprising" or "having" and any variations thereof are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0020] For ease of understanding, the specific process of the embodiments of this application is described below. Please refer to [link / reference]. Figure 1This application discloses a vehicle thermal protection control method applied to a vehicle. The vehicle includes an engine, a manual transmission, a cooling system, and a control unit. The manual transmission connects the engine to the wheels. The cooling system includes a cooling water circuit, which has a mechanical water pump, radiator water passages, a bypass water passage, a switching valve, and a thermostat. The mechanical water pump is driven by the engine. The switching valve is used to switch the on / off state of the radiator water passages. The thermostat is an electronic thermostat, located in the radiator water passages, used to open or close the radiator water passages according to the coolant temperature. One embodiment of the vehicle thermal protection control method includes: Step S1: Obtain the real-time vehicle speed and the real-time engine speed of the vehicle, and divide the real-time engine speed by the real-time vehicle speed to obtain the first real-time value. Specifically, simply looking at the engine speed cannot distinguish the engine's state. To determine whether the engine is under heavy load or no load, the vehicle's real-time speed and the engine's real-time speed are obtained. The ratio of engine speed to vehicle speed reflects the transmission relationship between the engine and the wheels, thus inferring the engine's actual load. Dividing the real-time engine speed by the real-time vehicle speed yields a primary real-time value. A large primary value indicates a high engine speed and low vehicle speed, possibly indicating the engine is in neutral, clutch disengaged, or in a low gear, with a relatively low engine load. A small primary value may indicate high-speed cruising with a relatively low load. A moderate ratio and low vehicle speed may correspond to heavy load climbing. By dividing the real-time engine speed by the real-time vehicle speed to obtain the primary real-time value, a basis is provided for subsequent dynamic adjustments to various thresholds.

[0021] It should be noted that when the vehicle speed is less than 1, there is a situation where the vehicle speed limit is close to 0. In this case, the first value obtained by dividing the real-time speed by the real-time engine speed will be close to infinity. Therefore, when the real-time speed is lower than the preset speed threshold, the preset value is used as the first value, such as the real-time engine speed.

[0022] Step S2: Determine the power transmission status. When the power transmission status is connected, dynamically set the overheat protection speed range. The overheat protection speed range includes an upper threshold and a lower threshold. The lower threshold is a preset reference speed, and the upper threshold is dynamically adjusted according to the first value and the on / off status of the radiator water channel. Specifically, in traditional engine overheat protection, protection is typically triggered by setting a fixed upper limit on engine speed. Protection is activated when the speed exceeds this threshold. However, single-threshold logic fails to adequately consider the dynamic balance between engine thermal load and heat dissipation capacity, potentially leading to misjudgments or missed detections under certain operating conditions. Research has revealed that at lower speeds (such as below idle or clutch engagement), engine load is typically low, resulting in less heat generation and making overheating less likely even after prolonged operation. At higher speeds, windward cooling is enhanced, and coolant circulation flow increases, resulting in stronger overall heat dissipation capacity and a relatively lower risk of overheating. In the mid-speed range, the engine often experiences higher loads (e.g., during hill climbing or acceleration), but vehicle speed remains low, and heat dissipation capacity has not yet significantly improved, making heat accumulation more likely and thus increasing the risk of overheating. Therefore, the risk of engine overheating does not increase monotonically with engine speed but is more concentrated within a certain intermediate speed range. Based on this, this application identifies high-risk areas by setting an overheat protection speed range, thereby ensuring engine safety while avoiding unnecessary power limiting under low-risk operating conditions.

[0023] Specifically, overheating risk only needs to be considered when the engine and wheels are connected. If power is disconnected (neutral, clutch depressed), even at high speeds, the load is small and overheating will not occur. Failure to distinguish this state could lead to false triggering of protection at high speeds in neutral. To ensure that overheat protection only activates when the engine is actually driving the vehicle, avoiding misjudgments under no-load conditions, the power transmission status is assessed. When the power transmission status is connected, the overheat protection speed range is dynamically set. The overheat protection speed range is used to define the dangerous operating range with load but insufficient heat dissipation. To obtain a speed range that accurately reflects the engine overheating risk under current operating conditions and improve the accuracy of overheating judgment, the overheat protection speed range is dynamically set. The overheat protection speed range includes an upper threshold and a lower threshold. The lower threshold is a preset reference speed, such as a value based on engine idle speed. Adding an offset to the idle speed represents the speed level at which the engine begins to bear significant load. When the speed is below the lower threshold, there is no risk of overheating even after prolonged operation. An engine's heat dissipation capacity is closely related to its engine speed, vehicle speed, and radiator condition. At the same engine speed, the greater the load (the smaller the first value), the more heat is generated, and the higher the risk of overheating; therefore, the upper limit should be lowered. When the radiator water passages are blocked, the heat dissipation capacity decreases, and the upper limit should also be lowered. Therefore, the upper limit threshold is dynamically adjusted based on the first value and the radiator water passage opening / closing status. By dynamically adjusting the upper limit threshold, accurate identification of dangerous zones can be achieved.

[0024] Step S3: When the real-time speed falls within the overheat protection speed range and the duration exceeds the first duration, execute the first control. Specifically, after dynamically setting the overheat protection speed range, it is necessary to monitor in real time whether the speed enters the high-risk area. However, short-term speed fluctuations will not cause overheating. Only continuous operation in the danger range will accumulate heat. Therefore, in order to avoid frequent start-stop control, after confirming that the engine is continuously in a high-risk operating condition, that is, when the real-time speed falls into the overheat protection speed range and the duration exceeds the first duration, the first control is executed. The first control refers to combustion suppression control. Combustion suppression can be achieved by skipping ignition or reducing fuel injection. Through the first control, the engine output power can be reduced, the engine heat generation is reduced, the temperature rise trend is suppressed, and overheating is avoided.

[0025] Step S4: Obtain the position of the switching valve and the status of the thermostat. Determine the status of the radiator water channel based on the position of the switching valve and the status of the thermostat. When the thermostat is in the closed state, dynamically adjust the opening temperature threshold. Specifically, the opening and closing of the radiator water passages can affect the heat dissipation capacity of the cooling system. If the radiator water passages are blocked, the coolant can only flow through the bypass water passages, resulting in a significant decrease in heat dissipation capacity. The engine is more prone to overheating, and the pressure in the bypass water passages is easily too high. Therefore, in order to identify whether the heat dissipation capacity of the cooling system is limited and to provide a basis for overheat risk assessment and pre-opening operation triggering, the actual state of the radiator water passages can be determined by monitoring the position of the switching valve or the state of the thermostat. If the switching valve position sensor indicates that the valve body is in the area where the radiator water passages are closed, or the thermostat is in the closed state, or both are closed at the same time, it is determined that the radiator is in a blocked state.

[0026] The thermostat is a key component in the cooling system that automatically controls the opening and closing of the radiator water channels. Its status directly affects the heat dissipation capacity. Even if the switching valve is in the open position, if the thermostat closes due to a malfunction or low temperature, the radiator water channels will still be blocked. In order to provide a basis for subsequent adjustment of the opening temperature and fault diagnosis, the current status of the thermostat is obtained by combining the thermostat position sensor or coolant temperature sensor with the thermostat characteristics. For example, if the coolant temperature is 70°C, which is lower than the thermostat's opening temperature of 82°C, it is determined that the thermostat is in the closed state. If the temperature reaches 85°C, the thermostat should be expected to open, but the sensor feedback is still that it is closed, which is determined to be a fault state. Traditional thermostats have a fixed opening temperature, which cannot adapt to different operating conditions. The thermostat in this application is an electronic thermostat. Under heavy load conditions, the thermostat opens earlier to increase heat dissipation, and under light load conditions, the thermostat opens later to maintain a higher temperature to improve fuel economy. Therefore, in order to make the opening temperature of the thermostat change with the engine load, the temperature threshold of the thermostat is dynamically adjusted so that the thermostat opens earlier under heavy load to enhance heat dissipation, and opens later under light load to maintain the engine operating temperature and improve efficiency.

[0027] Step S5: When the radiator water channel is detected to be blocked and the preset pre-opening trigger condition is met, the pre-opening operation is performed.

[0028] Specifically, the risk of excessive cooling system pressure may stem from various causes: operational behavior, operating conditions, and hardware failures. A single trigger condition cannot cover all risk scenarios. To prevent excessive cooling system pressure, the switching valve is activated in advance before the risk occurs. Reasonable and comprehensive trigger conditions are set to ensure timely activation of protection under any risk scenario. Three trigger conditions are connected by OR logic. A pre-opening operation is executed when any trigger condition is met. The three conditions are: real-time dynamic parameter risk (when the real-time speed is greater than the preset pre-opening trigger speed threshold and the rate of increase of the real-time speed is greater than the preset increase threshold); operating condition prediction risk (when the manual transmission is switched to a preset low gear after determining that the radiator water passage is blocked); and hardware failure risk (when the thermostat is closed and the coolant temperature is greater than the adjusted opening temperature threshold). The pre-opening operation is executed at an appropriate time based on the trigger conditions. The pre-opening operation refers to controlling the switching valve to drive the valve body to move towards opening the radiator water passage, allowing the coolant to start flowing to the radiator, reducing the bypass water passage pressure, and releasing the cooling system pressure in advance.

[0029] In one specific embodiment, the upper limit threshold is dynamically adjusted based on the first value and the on / off state of the radiator water channels, specifically including the following steps: Preset a basic upper limit value and a benchmark value, calculate the difference between the benchmark value and the first value, and calculate the first correction coefficient based on the difference; The second correction factor is determined based on the open / closed state of the radiator water passages. When the radiator water passages are in the open state, the second correction factor is set to 1. When the radiator water passages are in the closed state, the second correction factor is determined based on the degree of loss of engine cooling capacity caused by the radiator water passage closure. The upper limit value is obtained by multiplying the basic upper limit value by the first correction factor, and then by the second correction factor.

[0030] Specifically, the basic upper limit value can be preset based on experimental data of engine thermal load characteristics. During the experiment, the engine is run continuously at different speeds, and the changing trends of key thermal parameters such as coolant temperature, fuel temperature, and cylinder head temperature are monitored. The turning point speed at which the temperature begins to rise sharply is recorded. The turning point represents the critical point at which the engine begins to enter the risk of overheating under standard operating conditions. Based on this, a safety factor (usually 0-9-0.95) is multiplied to obtain the basic upper limit value. The upper limit value is usually 75%-85% of the engine's maximum output speed. The typical speed-vehicle speed ratio under the condition of constant speed driving on a flat road can be used as the benchmark value. For example, the most common constant speed cruising condition in daily driving is selected as the standard load condition. Under this condition, the engine load is moderate, neither idling at high speed nor heavily loaded climbing. The typical speed-vehicle speed ratio under this condition is determined statistically as the benchmark value. The actual thermal load of an engine depends not only on its speed but also on the magnitude of the driving load. At the same speed, a higher load generates more heat and increases the risk of overheating. To quantify the impact of load, a linear interpolation method is used to establish the correspondence between the first value and the correction coefficient. The design principle is as follows: the smaller the load, the larger the first value, and the upper limit threshold should be adjusted higher to allow the engine to operate at higher speeds without triggering protection; the larger the load, the smaller the first value, and the upper limit threshold should be adjusted lower to allow protection to intervene at lower speeds. The specific calculation is as follows: when the first value equals the reference value, the correction coefficient is set to 1, indicating no correction. The maximum and minimum values ​​of the correction coefficient are determined based on the engine load characteristics, typically between 0.8 and 1.2. The correction coefficient changes linearly with the ratio, and the change slope is... The rate is determined by both the coefficient range and the ratio range. Assuming the base value is 30, the correction coefficient range is 0.8-1.2, and the corresponding first value range is 5-60. The slope coefficient = (1.2-0.8) / (60-5) = 0.00727, and the first correction coefficient = 1+0.00727×30 = 1.22. When the first value is 60, the first correction coefficient is 1+0.00727×(60-30) = 1.22. When the first value is 15, the first correction coefficient is 1+0.00727×(15-30) = 0.89. The calculation of the first correction coefficient enables adaptive adjustment of the load. Under no-load high-speed conditions, the overheating judgment is relaxed, and under heavy-load conditions, the overheating judgment is tightened, making the thermal protection more accurate.

[0031] The accessibility of radiator water channels directly determines the cooling system's heat dissipation capacity. When radiator water channels are blocked, coolant can only flow through bypass channels, significantly reducing the heat dissipation area and decreasing heat dissipation capacity, thus increasing the risk of overheating at the same engine speed. To enable dynamic adjustment of the upper limit threshold based on the current heat dissipation capacity, experiments were conducted to determine the degree of heat dissipation capacity loss caused by radiator water channel blockage. Under the same operating conditions, the engine temperature rise rate was tested with and without radiator water channels, and the ratio of the temperature rise rate with blockage to that with water flow was calculated. This ratio reflects the degree of heat dissipation capacity reduction. The second correction factor can be the reciprocal of this ratio, for example, in the case of heat dissipation... When the radiator is filled with water, the coolant temperature rises from 80℃ to 90℃ in 10 minutes, with a temperature rise rate of 1℃ / minute. When the radiator is closed, the coolant temperature rises from 80℃ to 90℃ in 7 minutes, with a temperature rise rate of 1.43℃ / minute. The ratio of the temperature rise rates is 1.43 / 1 = 1.43, indicating a decrease in heat dissipation capacity of approximately (1.43-1) / 1.43 = 30%. The corresponding second correction coefficient is the reciprocal of the temperature rise rate ratio, which is 1 / 1.43 = 0.7. This second correction coefficient lowers the upper limit threshold when heat dissipation capacity is limited, allowing overheat protection to intervene at a lower speed, thus compensating for the risk caused by insufficient heat dissipation capacity. Finally, the basic upper limit value is multiplied by the first correction coefficient, and then by the second correction coefficient to obtain the upper limit threshold. The upper limit threshold is obtained through the above calculation method, realizing multi-factor coordinated control. Under harsh working conditions with high load and poor heat dissipation, the thermal protection will intervene at a low speed to maximize engine safety. Under working conditions with low load and normal heat dissipation, the engine is allowed to run at a higher speed without triggering the protection, avoiding unnecessary power loss.

[0032] In one specific embodiment, after step S5, the following steps are also performed: After the pre-start operation is executed, the real-time speed is continuously acquired. If the real-time speed is still within the overheat protection speed range and the first control is in the stopped state, the first control is executed. If the real-time speed is not within the overheat protection speed range and the first control is still being executed, the first control is stopped.

[0033] Specifically, after the pre-opening operation is executed, the switching valve begins to move towards opening the radiator water passages, and the cooling system's heat dissipation capacity gradually recovers. Simultaneously, the first control may still be executing or may have stopped. To assess whether there is still an overheating risk after the pre-opening operation takes effect, the latest real-time engine speed is obtained. If the engine speed is still within the overheat protection speed range, the engine may still overheat. To ensure that the heat load does not exceed the upper limit of the current heat dissipation capacity, if the first control is stopped at this time, it is executed; if the first control is executed, no changes are made, and the first control continues to be executed. If the real-time speed is no longer within the overheat protection speed range—that is, the real-time speed is below the lower threshold or above the upper threshold—it indicates that the engine has exited the high-risk area, and the execution of the first control can be stopped. If the first control is still executing at this time, its execution is stopped. The above method confirms whether the pre-opening operation effectively eliminates the overheating risk.

[0034] In one specific embodiment, the first control includes the following steps: The engine calculates the rate of increase of the real-time engine speed. When the rate of increase is greater than a preset emergency rate threshold, the engine's ignition system is controlled to not perform ignition operation in at least one working cycle. When the rate of increase is less than or equal to the emergency rate threshold, the amount of fuel supplied to the combustion chamber is reduced.

[0035] Specifically, the rate of increase in engine speed reflects the drastic change in engine load. A high rate of increase indicates a rapidly escalating risk of overheating during rapid acceleration or sudden load changes, requiring a quick response. A low rate of increase indicates a more moderate risk, allowing for a more gradual adjustment. To determine the type of risk, an emergency rate threshold is preset. The urgency of the overheating risk is quantified by the rate of increase. This emergency rate threshold can be calibrated experimentally, typically taking the maximum rate of increase that the engine can safely respond to. Skipping ignition reduces torque output in a very short time (the next ignition cycle), offering a fast response and making it suitable for handling the instantaneous overheating risk caused by sudden high rates of increase. Therefore, when the rate of increase exceeds the emergency rate threshold, ignition is not performed in at least one working cycle. In other words, ignition is skipped in the following working cycles; for example, one cycle out of every two cycles can be skipped for no ignition. When the rate of increase is less than or equal to the emergency rate threshold, it indicates a gradual increase in engine speed and a slower risk development, requiring no immediate and drastic intervention. By reducing fuel injection, output can be smoothly reduced while maintaining combustion stability. The above method distinguishes between urgent risks based on the rate of increase in rotational speed and adopts different control methods accordingly, so as to achieve different responses to overheating risks of different urgency levels. It can quickly intervene in urgent risks and deal with non-urgent risks.

[0036] In one specific embodiment, adjusting the activation temperature threshold based on a first value specifically includes the following steps: The system presets a base opening temperature value, a reference value, and a logarithmic adjustment coefficient. It then calculates the ratio of the current first value to the reference value, performs a logarithmic transformation on the ratio to obtain a deviation index, multiplies the deviation index by the logarithmic adjustment coefficient, and adds 1 to obtain a temperature correction coefficient. Finally, it multiplies the base opening temperature value by the temperature correction coefficient to obtain the adjusted opening temperature threshold.

[0037] Specifically, a fixed radiator opening temperature cannot be adjusted according to specific conditions, making on-demand heat dissipation impossible. To achieve earlier heat dissipation under heavy load and later heat dissipation under light load—for example, under heavy load, a lower temperature is desired, so the radiator needs to be turned on earlier to allow for additional heat generation—and under light load, a higher temperature is desired, so the radiator is turned on later to improve thermal efficiency. First, a baseline opening temperature value is preset. This baseline opening temperature value is determined during engine design based on thermal balance and fuel economy, representing the ideal opening temperature under standard operating conditions. It provides the basic data for subsequent dynamic corrections. The baseline value is the same as the baseline value used to calculate the upper limit threshold, representing the typical speed-to-vehicle ratio under constant speed driving conditions on a flat road. To control the extent to which the opening temperature deviates from the first value, a corresponding logarithmic adjustment coefficient is determined through experimental or simulation optimization. The logarithmic adjustment coefficient is a sensitivity coefficient for temperature correction to deviation, measuring the temperature correction magnitude caused by a unit logarithmic deviation. The deviation needs to reflect the degree of deviation of the current first value from the reference value, and it is desirable that the larger the deviation, the larger the adjustment range, but the adjustment range should be naturally saturated to avoid over-adjustment. In order to convert the deviation of the first value into a dimensionless deviation index with natural saturation characteristics, the current first value is first divided by the reference value to obtain the ratio of the first value to the reference value. Then, the natural logarithm of the ratio is taken to obtain the deviation index. The logarithmic function makes the deviation increase by a fixed value when the deviation multiple doubles. When the deviation multiple is very large, the deviation increases slowly, achieving natural saturation. In order to obtain the temperature correction coefficient, the deviation index is converted into a coefficient that can be directly multiplied by the base opening temperature. By adding 1, the temperature correction coefficient is 1 when the deviation is 0, indicating that no correction is made when the deviation is 0. Finally, the base opening temperature value is multiplied by the temperature correction coefficient to obtain the adjusted opening temperature threshold.

[0038] In one specific embodiment, the pre-activation trigger condition specifically includes: The real-time rotational speed is greater than the pre-activated trigger speed threshold, and the rate of increase of the real-time rotational speed is greater than the preset increase threshold.

[0039] Specifically, during vehicle operation, rapid acceleration causes the engine speed to rise rapidly. When the radiator water passages are blocked, the rapid increase in speed causes a sudden increase in the mechanical water pump flow rate, forcing a large amount of coolant into the narrow bypass water passages, resulting in a sharp increase in water pressure. If intervention is delayed until the pressure exceeds the limit, it may cause water pipes to detach or heater cores to rupture. Therefore, to initiate a pre-opening operation before the rapid increase in speed leads to excessive pressure, and to buy time for the radiator water passages to fully open, thus preventing damage to the cooling system due to excessive pressure, the engine speed and its rate of change are continuously monitored. When both the speed reaches the pre-opening trigger speed threshold (the current speed is at a level that may cause excessive pressure) and the rate of increase reaches the increase threshold (the speed is rising rapidly, and the pressure is increasing sharply), it indicates that there is a high risk, and the risk is accelerating, requiring immediate intervention. The above triggering conditions allow for intervention before the pressure exceeds the limit. When the speed reaches the point that may cause excessive pressure, the radiator water passages have already opened, effectively releasing the pressure.

[0040] In one specific embodiment, the step of setting the pre-activation trigger speed threshold specifically includes the following steps: The system presets the base and start-up speed values ​​and reference values. Based on the comparison between the current first value and the reference value, it calculates the venting correction coefficient using the piecewise linear difference method. It then multiplies the base and start-up speed values ​​by the venting correction coefficient to obtain the initial pre-start-up trigger speed threshold. It checks whether the first control is being executed. If so, it multiplies the initial pre-start-up trigger speed threshold by the preset coefficient to obtain the final pre-start-up trigger speed threshold. Otherwise, it uses the initial pre-start-up trigger speed threshold as the final pre-start-up trigger speed threshold.

[0041] Specifically, in order to establish a pre-opening trigger benchmark under standard operating conditions and provide basic values ​​for subsequent dynamic correction, a base and opening speed value is preset. The base and opening speed values ​​are calibrated based on the pressure characteristics of the engine cooling system under the radiator water channel blockage state. They are taken as 80%-90% of the speed corresponding to the allowable upper limit when the bypass water channel pressure reaches the upper limit when the radiator water channel is blocked. The benchmark value is the same as the benchmark value of the previously calculated upper limit threshold, which is the typical speed-vehicle speed ratio when the vehicle is driving at a constant speed on a flat road. Cooling system pressure risk depends not only on engine speed but also on vehicle operating conditions. Under different operating conditions, the same engine speed may correspond to different pressure risk levels. Therefore, it is necessary to quantify the impact of operating conditions on risk using a first value. In order to dynamically adjust the pre-opening trigger speed threshold according to operating conditions, a piecewise linear difference method is used to establish the correspondence between the ratio and the correction coefficient. When the first value is greater than or equal to the reference value, it indicates that the first value is large. At this time, the engine load may be low, the engine speed is high, the water pump flow is large, and the bypass water channel pressure risk is high. Therefore, the pre-opening trigger speed threshold should be lowered to make the pre-opening operation easier to trigger. When the first value is less than or equal to the reference value, it indicates that the engine speed is relatively low and the pressure risk is small. The pre-opening trigger speed threshold can be increased to avoid unnecessary pre-opening operations. Therefore, when the first value is greater than or equal to the reference value, the venting correction coefficient is linearly decreased from 1 as the first value increases until the minimum correction coefficient is reached. When the first value is less than the reference value, the correction coefficient is linearly increased from 1 until the maximum correction coefficient is reached. Assuming a base value of 30, a minimum ratio of 5, a maximum ratio of 100, a minimum correction coefficient of 0.5, and a maximum correction coefficient of 1.5, the slope k1 when the first value is greater than or equal to the base value is calculated as k1 = (1-0.5) / (100-30) = 0.5 / 70 = 0.00714, and the slope k2 when the first value is less than the base value is calculated as k2 = (1.5-1) / (30-5) = 0.5 / 25 = 0.02. When the first value is 80, the venting correction coefficient is calculated as 1-0.00714×(80-30) = 1-0.357 = 0.643. When the first value is 15, the venting correction coefficient is calculated as 1+0.02×(30-15) = 1.3. In order to combine the base value and the operating condition correction factor to form a comprehensive trigger threshold, the operating condition influence is incorporated into the pre-opening trigger judgment through multiplication. That is, the base and opening speed values ​​are multiplied by the venting correction coefficient to obtain the initial pre-opening trigger speed threshold. After the first control is executed, the engine output power decreases, the heat generation decreases, and the rate of increase in cooling system pressure also slows down accordingly. At this time, the urgency requirement for pre-opening operation is reduced, so the triggering conditions can be appropriately relaxed. Therefore, when the first control is being executed, the initial pre-opening trigger speed threshold is multiplied by a preset coefficient to obtain the final pre-opening trigger speed threshold. The preset coefficient is greater than 1, usually 1.1 or 1.2. Otherwise, the initial pre-opening trigger speed threshold is used as the final pre-opening trigger speed threshold.

[0042] In one specific embodiment, the pre-activation trigger condition further includes: The clutch is disengaged and the real-time rotational speed is greater than a preset threshold.

[0043] Specifically, when a manual transmission vehicle is decelerating, the driver will downshift to achieve engine braking. At the moment of downshifting, when the clutch engages, the engine is dragged by the wheels, and the speed may spike instantly. If the radiator water passage is blocked at this time, the increase in speed may cause the cooling system pressure to exceed the limit instantly. Since it is a transient event, conventional speed threshold judgment may not be able to respond in time. In order to identify driving operations such as deceleration and downshifting, when the clutch is disengaged and the real-time speed is greater than the preset deceleration and downshifting judgment threshold, a pre-opening operation is initiated in advance to deal with transient high-risk events.

[0044] In one specific embodiment, the pre-activation trigger condition further includes: The thermostat is closed, and the coolant temperature is higher than the adjusted opening temperature threshold.

[0045] Specifically, the thermostat is a mechanical component that may malfunction after prolonged use, preventing it from opening properly. If the thermostat remains closed at the temperature it should open, the radiator water passages will also be blocked, limiting the engine's cooling capacity. Prolonged operation will inevitably lead to overheating. This type of hardware failure cannot be identified through normal operating conditions. Therefore, if the thermostat is closed and the coolant temperature is higher than the adjusted opening temperature threshold, a thermostat failure is identified. Since the coolant temperature is higher than the adjusted opening temperature threshold, a pre-opening operation is triggered, driving the switching valve to forcibly open the radiator water passages, allowing coolant to flow to the radiator and curbing the temperature rise.

[0046] The above describes a vehicle thermal protection control method according to an embodiment of this application. The following describes a vehicle thermal protection control system according to an embodiment of this application. Please refer to [link / reference]. Figure 2 One embodiment of a vehicle thermal protection control system in this application includes: The parameter calculation unit is used to obtain the real-time vehicle speed and the real-time engine speed of the vehicle, and divide the real-time engine speed by the real-time vehicle speed to obtain the first real-time value. The interval setting unit is used to determine the power transmission status. When the power transmission status is connected, the overheat protection speed range is dynamically set. The overheat protection speed range includes an upper limit threshold and a lower limit threshold. The lower limit threshold is a preset reference speed, and the upper limit threshold is dynamically adjusted according to the first value and the on / off status of the radiator water channel. The overheat control unit is used to monitor the real-time speed. When the real-time speed falls within the overheat protection speed range and the duration exceeds the first duration, the first control is executed. The threshold adjustment unit is used to obtain the position of the switching valve and the status of the thermostat, and to determine the status of the radiator water channel based on the position of the switching valve and the status of the thermostat. When the thermostat is in the closed state, the opening temperature threshold is dynamically adjusted. The activation control unit is used to perform a pre-activation operation when the radiator water channel is detected to be blocked and the preset pre-activation trigger conditions are met.

[0047] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0048] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0049] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A vehicle thermal protection control method, characterized in that, The method includes: Step S1: Obtain the real-time vehicle speed and the real-time engine speed of the vehicle, and divide the real-time engine speed by the real-time vehicle speed to obtain the first real-time value. Step S2: Determine the power transmission status. When the power transmission status is connected, dynamically set the overheat protection speed range. The overheat protection speed range includes an upper threshold and a lower threshold. The lower threshold is a preset reference speed, and the upper threshold is dynamically adjusted according to the first value and the on / off status of the radiator water channel. Step S3: When the real-time speed falls within the overheat protection speed range and the duration exceeds the first duration, execute the first control. Step S4: Obtain the position of the switching valve and the status of the thermostat. Determine the status of the radiator water channel based on the position of the switching valve and the status of the thermostat. When the thermostat is in the closed state, dynamically adjust the opening temperature threshold. Step S5: When the radiator water channel is detected to be blocked and the preset pre-opening trigger condition is met, the pre-opening operation is performed.

2. The method according to claim 1, characterized in that, The upper limit threshold is dynamically adjusted based on the first value and the on / off status of the radiator water channels, including: Preset a basic upper limit value and a benchmark value, calculate the difference between the benchmark value and the first value, and calculate the first correction coefficient based on the difference; The second correction factor is determined based on the open / closed state of the radiator water passages. When the radiator water passages are in the open state, the second correction factor is set to 1. When the radiator water passages are in the closed state, the second correction factor is determined based on the degree of loss of engine cooling capacity caused by the radiator water passage closure. The upper limit value is obtained by multiplying the basic upper limit value by the first correction factor, and then by the second correction factor.

3. The method according to claim 1, characterized in that, After step S5, the following also includes: After the pre-start operation is executed, the real-time speed is continuously acquired. If the real-time speed is still within the overheat protection speed range and the first control is in the stopped state, the first control is executed. If the real-time speed is not within the overheat protection speed range and the first control is still being executed, the first control is stopped.

4. The method according to claim 1, characterized in that, The first control includes: The engine calculates the rate of increase of the real-time engine speed. When the rate of increase is greater than a preset emergency rate threshold, the engine's ignition system is controlled to not perform ignition operation in at least one working cycle. When the rate of increase is less than or equal to the emergency rate threshold, the amount of fuel supplied to the combustion chamber is reduced.

5. The method according to claim 1, characterized in that, Adjust the activation temperature threshold based on the first value, including: The system presets a base opening temperature value, a reference value, and a logarithmic adjustment coefficient. It then calculates the ratio of the current first value to the reference value, performs a logarithmic transformation on the ratio to obtain a deviation index, multiplies the deviation index by the logarithmic adjustment coefficient, and adds 1 to obtain a temperature correction coefficient. Finally, it multiplies the base opening temperature value by the temperature correction coefficient to obtain the adjusted opening temperature threshold.

6. The method according to claim 1, characterized in that, Pre-activation trigger conditions include: The real-time rotational speed is greater than the preset pre-activation trigger speed threshold, and the rate of increase of the real-time rotational speed is greater than the preset increase threshold.

7. The method according to claim 1, characterized in that, The steps for setting the pre-activation trigger speed threshold include: The system presets the base and start-up speed values ​​and reference values. Based on the comparison between the current first value and the reference value, it calculates the venting correction coefficient using the piecewise linear difference method. It then multiplies the base and start-up speed values ​​by the venting correction coefficient to obtain the initial pre-start-up trigger speed threshold. It checks whether the first control is being executed. If so, it multiplies the initial pre-start-up trigger speed threshold by the preset coefficient to obtain the final pre-start-up trigger speed threshold. Otherwise, it uses the initial pre-start-up trigger speed threshold as the final pre-start-up trigger speed threshold.

8. The method according to claim 1, characterized in that, Pre-activation trigger conditions include: The clutch is disengaged and the real-time rotational speed is greater than a preset threshold.

9. The method according to claim 1, characterized in that, Pre-activation trigger conditions include: The thermostat is closed, and the coolant temperature is higher than the adjusted opening temperature threshold.

10. A vehicle thermal protection control system, used to implement the vehicle thermal protection control method as described in any one of claims 1-8, characterized in that, The system includes: The parameter calculation unit is used to obtain the real-time vehicle speed and the real-time engine speed of the vehicle, and divide the real-time engine speed by the real-time vehicle speed to obtain the first real-time value. The interval setting unit is used to determine the power transmission status. When the power transmission status is connected, the overheat protection speed range is dynamically set. The overheat protection speed range includes an upper limit threshold and a lower limit threshold. The lower limit threshold is a preset reference speed, and the upper limit threshold is dynamically adjusted according to the first value and the on / off status of the radiator water channel. The overheat control unit is used to monitor the real-time speed. When the real-time speed falls within the overheat protection speed range and the duration exceeds the first duration, the first control is executed. The threshold adjustment unit is used to obtain the position of the switching valve and the status of the thermostat, and to determine the status of the radiator water channel based on the position of the switching valve and the status of the thermostat. When the thermostat is in the closed state, the opening temperature threshold is dynamically adjusted. The activation control unit is used to perform a pre-activation operation when the radiator water channel is detected to be blocked and the preset pre-activation trigger conditions are met.

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