Engine outlet water temperature correction method, device, storage medium and system

Abstract

The invention provides an engine outlet water temperature correction method and device, a storage medium and a system, and relates to the technical field of engine control, the method comprises the steps that the current water temperature value of an engine is obtained, and the current water temperature value is a measured value of a water temperature sensor in the engine; constructing a water temperature model according to the current water temperature value of the engine and the engine oil temperature; and under the condition that the hydraulic retarder is in the braking working condition or the hydraulic retarder quits the braking working condition and a preset duration passes after the hydraulic retarder quits the braking working condition, the current water temperature value of the engine is corrected according to the water temperature model, and the corrected water temperature value serves as the actual water temperature value of the engine. The problem that in the prior art, when the hydraulic retarder is in the braking working condition or just quits the braking working condition, the reading of the water temperature sensor is virtually high, and consequently wrong cooling control is triggered is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engine control, in particular to an engine outlet water temperature correction method, an engine outlet water temperature correction device, a computer readable storage medium and an engine outlet water temperature correction system. BACKGROUND

[0002] The water temperature parameter of the engine cooling system is an important basis for the engine control unit to adjust and protect the operation of the engine. The water temperature is not only related to the calculation of friction torque, power output and overheat protection, but also directly affects the speed control of the water pump and fan and the diagnosis and efficiency of the exhaust aftertreatment system. Therefore, the accuracy of the cooling liquid temperature collected by the water temperature sensor is of great significance to the stability and reliability of the engine.

[0003] In the prior art, the engine water temperature sensor is usually arranged after the EGR (Exhaust Gas Recirculation) cooler to reflect the outlet water temperature of the engine. However, in some vehicle models, due to the space arrangement limitation of the host factory, the hydraulic retarder is designed before the EGR cooler, and at this time the water temperature sensor is located after the hydraulic retarder. When the hydraulic retarder brake is turned on, abnormal heat accumulation will occur in the local cooling circuit, causing the water temperature sensor detection value to be "falsely high", resulting in the engine control system making an error control decision based on the false signal, thereby affecting the stability of the engine and the vehicle operation. SUMMARY

[0004] The main purpose of the present application is to provide an engine outlet water temperature correction method, an engine outlet water temperature correction device, a computer readable storage medium and an engine outlet water temperature correction system to at least solve the problem of false high reading of the water temperature sensor when the hydraulic retarder is in the braking condition or just exits the braking condition, which leads to triggering of an error cooling control in the prior art.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present application, an engine outlet water temperature correction method is provided, comprising: acquiring a current water temperature value of an engine, the current water temperature value being a measurement value of a water temperature sensor in the engine; constructing a water temperature model according to the current water temperature value of the engine and an oil temperature; in the case that a hydraulic retarder is in a braking condition, or in the case that the hydraulic retarder exits the braking condition and a preset time period has elapsed after the hydraulic retarder exits the braking condition, correcting the current water temperature value of the engine according to the water temperature model, and taking the corrected water temperature value as an actual water temperature value of the engine.

[0006] Optionally, the correcting the current water temperature value of the engine according to the water temperature model, and taking the corrected water temperature value as an actual water temperature value of the engine comprises: obtaining the oil temperature, and determining a first change amount of the oil temperature in a preset time period when the oil temperature is less than or equal to a first preset temperature; determining a first correction coefficient according to the current water temperature value of the engine; and determining the actual water temperature value of the engine according to the first change amount, the first correction coefficient and the current water temperature value of the engine.

[0007] Optionally, the method further comprises: obtaining a coolant temperature passing through an EGR cooler when the oil temperature is greater than the first preset temperature; determining a second change amount of the coolant temperature passing through the EGR cooler in the preset time period when the coolant temperature passing through the EGR cooler is less than or equal to a second preset temperature; and determining the actual water temperature value of the engine according to the second change amount, the first correction coefficient and the current water temperature value of the engine.

[0008] Optionally, the determining a first correction coefficient according to the current water temperature value of the engine comprises: determining, according to the current water temperature value of the engine and a preset mapping relationship table of water temperature values and correction coefficients, that the correction coefficient corresponding to the current water temperature value of the engine is the first correction coefficient, the water temperature values and the correction coefficients being in one-to-one correspondence.

[0009] Optionally, the determining the actual water temperature value of the engine according to the first change amount, the first correction coefficient and the current water temperature value of the engine comprises: obtaining a product of the first change amount and the first correction coefficient; and determining, as the actual water temperature value of the engine, a difference between the current water temperature value of the engine and the product.

[0010] Optionally, the method further comprises: determining the actual water temperature value of the engine according to a preset change amount, the first correction coefficient and the current water temperature value of the engine when the coolant temperature passing through the EGR cooler is greater than the second preset temperature, wherein the preset change amount is determined based on historical data.

[0011] Optionally, the method further comprises: controlling the actual water temperature value of the engine to change to the current water temperature value of the engine at a preset rate when the hydraulic retarder exits the braking working condition and after the preset time period elapses after the hydraulic retarder exits the braking working condition.

[0012] According to another aspect of the present application, a correction device for engine outlet water temperature is provided, comprising: an acquisition unit configured to acquire a current water temperature value of an engine, the current water temperature value being a measured value of a water temperature sensor in the engine; a construction unit configured to construct a water temperature model according to the current water temperature value of the engine and an oil temperature; and a correction unit configured to correct the current water temperature value of the engine according to the water temperature model in a case where a hydraulic retarder is in a braking condition, or in a case where the hydraulic retarder exits the braking condition and a preset time period has elapsed after the hydraulic retarder exits the braking condition, and to take a corrected water temperature value as an actual water temperature value of the engine.

[0013] According to still another aspect of the present application, a computer readable storage medium is provided, the computer readable storage medium comprising a stored program, wherein the program, when executed, controls a device in which the computer readable storage medium is located to perform any of the methods.

[0014] According to yet another aspect of the present application, a correction system for engine outlet water temperature is provided, comprising: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs comprise instructions for performing any of the methods.

[0015] According to the technical solution of the present application, a measured value of a water temperature sensor in an engine is first acquired as a current water temperature value of the engine, then a water temperature model is constructed according to the current water temperature value of the engine and an oil temperature; in a case where a hydraulic retarder is in a braking condition, or in a case where the hydraulic retarder exits the braking condition and a preset time period has elapsed after the hydraulic retarder exits the braking condition, the current water temperature value of the engine is corrected according to the water temperature model, and a corrected water temperature value is taken as an actual water temperature value of the engine. The present application corrects the engine outlet water temperature collected by the water temperature sensor through the water temperature model in a case where the hydraulic retarder is in the braking condition or just exits the braking condition, thereby avoiding the measurement deviation of the sensor caused by the heat exchange of the hydraulic retarder, making the water temperature value closer to the real thermal state of the engine, and further improving the stability and reliability of the vehicle operation, and solving the problem of false high reading of the water temperature sensor in the prior art in a case where the hydraulic retarder is in the braking condition or just exits the braking condition, which leads to the triggering of an error cooling control. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application and are incorporated herein for a purpose of explanations of the present application and are not intended as improper limitations to the present application. In the drawings:

[0017] Figure 1A flowchart of a method for correcting an engine outlet water temperature according to an embodiment of the present application is shown;

[0018] Figure 2 A flowchart of a method for correcting an engine outlet water temperature according to an embodiment of the present application is shown;

[0019] Figure 3 A flowchart of a method for correcting an engine outlet water temperature according to an embodiment of the present application is shown;

[0020] Figure 4 A flowchart of a method for correcting an engine outlet water temperature according to an embodiment of the present application is shown;

[0021] Figure 5 A flowchart of a method for correcting an engine outlet water temperature according to an embodiment of the present application is shown;

[0022] Figure 6 A flowchart of a method for correcting an engine outlet water temperature according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0023] It should be noted that the embodiments and features of the embodiments in the present application can be combined if there is no conflict. The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0024] In order to enable persons skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings and in combination with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative labor should fall within the scope of protection of the present application.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily limit to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0026] As introduced in the background, the prior art has the problem that the water temperature sensor reading is too high when the hydraulic retarder is in the braking condition or just exits the braking condition, resulting in triggering of the false cooling control. To solve the above technical problem, the embodiments of the present application provide a correction method of engine outlet water temperature, a correction device of engine outlet water temperature, a computer readable storage medium and a correction system of engine outlet water temperature.

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings of the embodiments of the present application.

[0028] Figure 1 is a flowchart of the correction method of engine outlet water temperature according to the embodiments of the present application. As shown in Figure 1 , the method comprises the following steps:

[0029] Step S101, acquiring a current water temperature value of an engine, wherein the current water temperature value is a measurement value of a water temperature sensor in the engine;

[0030] Step S102, constructing a water temperature model according to the current water temperature value of the engine and an oil temperature;

[0031] Specifically, the water temperature model is established based on the current water temperature value of the engine and the oil temperature as core parameters, and the combination of the two can more accurately reflect the thermal state of the engine. However, it should be understood that the water temperature model is not limited to being based on the above parameters, such as the coolant temperature passing through the EGR cooler, the ambient temperature, the engine speed, etc.

[0032] Step S103, when the hydraulic retarder is in the braking condition, or when the hydraulic retarder exits the braking condition and a preset time period has elapsed after the hydraulic retarder exits the braking condition, correcting the current water temperature value of the engine according to the water temperature model, and taking the corrected water temperature value as the actual water temperature value of the engine.

[0033] Specifically, when the hydraulic retarder is in the braking condition, or when the hydraulic retarder exits the braking condition and a certain preset time period has elapsed after the exit, the actual temperature state of the engine is often affected by the heat conduction of the retarder, resulting in deviation of the temperature value measured by the water temperature sensor. For this situation, the water temperature model is used to correct the current water temperature value collected by the sensor, which can filter out the transient interference introduced by the operation of the retarder, so that the corrected water temperature value is closer to the true thermal state of the engine.

[0034] Through the above embodiment, firstly, the measured value of the water temperature sensor in the engine is obtained as the current water temperature value of the engine, and then the water temperature model is constructed according to the current water temperature value of the engine and the oil temperature; in the case that the hydraulic retarder is in the braking working condition, or in the case that the hydraulic retarder exits the braking working condition and a preset time period has elapsed after the hydraulic retarder exits the braking working condition, the current water temperature value of the engine is corrected according to the water temperature model, and the corrected water temperature value is taken as the actual water temperature value of the engine. Through the above scheme, in the case that the hydraulic retarder is in the braking working condition or just exits the braking working condition, the engine outlet water temperature collected by the water temperature sensor is corrected through the water temperature model, so that the measurement deviation of the sensor caused by the heat exchange effect of the hydraulic retarder is avoided, the water temperature value is closer to the real thermal state of the engine, and the stability and reliability of the vehicle operation are improved. The problem that the water temperature sensor reading is too high when the hydraulic retarder is in the braking working condition or just exits the braking working condition, and the cooling control is triggered incorrectly is solved.

[0035] In an optional scheme, as shown in Figure 2 the water temperature model is used to correct the current water temperature value of the engine, and the corrected water temperature value is taken as the actual water temperature value of the engine, which includes:

[0036] Step S201, the oil temperature is obtained, and in the case that the oil temperature is less than or equal to a first preset temperature, a first change amount of the oil temperature in a preset time period is determined;

[0037] Step S202, a first correction coefficient is determined according to the current water temperature value of the engine;

[0038] Step S203, the actual water temperature value of the engine is determined according to the first change amount, the first correction coefficient and the current water temperature value of the engine.

[0039] In the above embodiment, by correcting the engine water temperature value in combination with the correction coefficient determined by the current water temperature value when the oil temperature is less than or equal to the first preset temperature, the oil temperature change trend can reflect the heat accumulation caused by engine friction and load, and in the low temperature range, the correlation between the oil temperature and the water temperature is stronger, and the use of the oil temperature change amount to correct the water temperature value can more accurately reflect the real thermal state of the engine cooling system. If the measurement value of the water temperature sensor is simply relied on, deviation may occur in the hydraulic retarder braking and other working conditions, and the introduction of the oil temperature change trend as a comparison and correction basis helps to avoid misjudgment caused by sensor position or transient interference, and helps the ECU (Electronic Control Unit) to make more accurate control in the overheat protection, avoiding problems such as excessive torque limiting or abnormal speed fluctuation. Through the combination of the current water temperature value, the positive coefficient and the oil temperature change amount, the temperature information from different sources is integrated, the adaptability of the system in different working conditions is improved, and good reliability can still be maintained when the hydraulic retarder frequently intervenes or the environmental temperature fluctuates greatly.

[0040] Specifically, in the case where the oil temperature is less than or equal to the first preset temperature, it indicates that the engine is in a low temperature working condition, and at this time, the fluctuation of the oil temperature has a more direct reflection on the thermal state of the engine cooling system. Therefore, under this condition, the change amount of the oil temperature in the preset time period is further determined as an auxiliary variable for water temperature correction. According to the current water temperature value of the engine, a corresponding first correction coefficient is determined. The correction coefficient reflects the sensitivity of the oil temperature change to the water temperature correction at different water temperature levels. The above first preset temperature is a threshold value for determining whether the oil temperature is in a low temperature or normal temperature range, which is obtained based on the thermal characteristics of the engine in different operating states through test calibration and historical data analysis. In the specific implementation process, the corresponding relationship between the oil temperature and the engine water temperature change can be collected in the engine cooling system bench test or vehicle road test, and when the oil temperature is lower than a certain value, the change trend has the strongest correlation with the water temperature correction, and this value is used as a reference for the first preset temperature.

[0041] In another optional solution, as shown in Figure 3 The above method further comprises:

[0042] Step S301, in the case where the above oil temperature is greater than the above first preset temperature, the cooling liquid temperature passing through the EGR (Exhaust Gas Recirculation) cooler is obtained;

[0043] Step S302, in the case where the above cooling liquid temperature passing through the above EGR cooler is less than or equal to the second preset temperature, a second change amount of the above cooling liquid temperature in the above preset time period is determined;

[0044] Step S303, determining the actual water temperature value of the engine according to the second change amount, the first correction coefficient, and the current water temperature value of the engine.

[0045] In the above embodiment, when the oil temperature exceeds the first preset temperature, the oil heat is close to saturation, and the change trend is no longer consistent with the coolant temperature. At this time, if the correction is continued to be made by relying on the oil temperature change amount, the water temperature correction value will be distorted. By introducing the EGR coolant temperature as an alternative reference, the distortion problem caused by the high oil temperature saturation can be avoided. The EGR cooler is in the exhaust gas heat exchange path, and the outlet coolant temperature is sensitive to the engine heat load and cooling efficiency. By extracting the change amount of the coolant temperature in a preset time period when the coolant temperature is less than or equal to the second preset temperature, a dynamic quantity highly related to the engine cooling state can be obtained as an input for correction calculation. The actual water temperature value obtained by comprehensively calculating the second change amount, the correction coefficient, and the current water temperature value avoids the error caused by the abnormality of a single sensor signal, so that the water temperature correction model is still reliable in high-temperature working conditions and when the retarder frequently intervenes. The corrected actual water temperature value can provide more real temperature information for the ECU, so as to realize more reasonable adjustment in friction torque calculation, overheat protection torque limiting, and the like, and avoid the overwork of the cooling system or the abnormal triggering of the protection strategy caused by the water temperature misjudgment.

[0046] Specifically, when the oil temperature has exceeded the first preset temperature, it indicates that the oil itself is in a high-temperature state, and the temperature change speed tends to slow down. At this time, the correlation between the temperature rise of the oil and the water temperature of the cooling system is weakened, and the oil temperature can no longer sensitively reflect the actual change of the coolant temperature, so the coolant temperature passing through the EGR cooler is introduced as a correction basis.

[0047] In some example embodiments, the first correction coefficient is determined according to the current water temperature value of the engine, including: determining the correction coefficient corresponding to the current water temperature value of the engine as the first correction coefficient according to the current water temperature value of the engine and a preset mapping relationship table of water temperature values and correction coefficients, wherein the water temperature values and the correction coefficients are in one-to-one correspondence.

[0048] In the above embodiment, by establishing the mapping relationship between the water temperature value and the correction coefficient, different correction amplitudes can be set for each temperature interval, so that the correction model can maintain reasonable sensitivity in the low temperature zone and the high temperature zone. Due to the position of the water temperature sensor and the working condition of the retarder, the water temperature measurement deviation is caused, and through the one-to-one mapping relationship, the randomness caused by manual selection or temporary calculation can be avoided. Each water temperature value corresponds to a unique correction coefficient, thereby ensuring the stability of the correction result. In actual operation, only the current water temperature value needs to be read, and the corresponding correction coefficient in the mapping table needs to be found, without the need for complex real-time calculation. This way greatly reduces the occupation of computing resources and improves the response speed of the control system.

[0049] The corresponding relationship between the water temperature value and the correction coefficient can be obtained through test calibration, and adjusted according to different engine models or application conditions. When the above current water temperature value is not in the mapping table, the correction coefficient can be determined by linear interpolation method according to the correction coefficients of the adjacent two water temperature values, and the correction coefficient between the two points is obtained by proportional calculation.

[0050] In some other example embodiments, as shown in Figure 4 The actual water temperature value of the engine is determined according to the first change amount, the first correction coefficient, and the current water temperature value of the engine, including:

[0051] Step S401, obtaining the product of the first change amount and the first correction coefficient;

[0052] Step S402, determining the difference between the current water temperature value of the engine and the product as the actual water temperature value of the engine.

[0053] In the above embodiment, the first change amount reflects the change trend of the oil temperature in a certain period of time, which can represent the dynamic process of engine heat input. By determining the difference between the current water temperature value of the engine and the product as the actual water temperature value of the engine, the instantaneous interference caused by the hydraulic retarder braking or local uneven heat dissipation can be effectively filtered out, the sensitivity of the model to small amplitude temperature changes is improved, the ECU can more timely and accurately identify the real change of the water temperature, and the amplification effect of single point data anomaly is avoided, thereby ensuring that the correction result is more stable, further providing data support for overheat protection strategy, and avoiding the problem of triggering false cooling control.

[0054] Specifically, the actual water temperature value of the engine is determined according to Q1=Q2-|△r|×k, wherein Q1 is the actual water temperature value of the engine, Q2 is the current water temperature value of the engine, k is the first correction coefficient, and △r is the first change amount.

[0055] In an alternative, the method further comprises: in the case that the coolant temperature at the outlet of the EGR cooler is greater than the second preset temperature, determining the actual water temperature value of the engine according to a preset variation, the first correction coefficient, and the current water temperature value of the engine, wherein the preset variation is determined based on historical data.

[0056] In the above embodiment, by introducing a preset variation determined based on historical data to correct the water temperature in the case that the coolant temperature at the outlet of the EGR cooler is greater than the second preset temperature, the preset variation established based on historical data is used as a replacement parameter in the case that the real-time data is distorted or unavailable, to provide a reliable reference. The historical data is derived from long-term collection of the engine under different operating conditions, and can better reflect the typical temperature variation trend. By introducing historical data under abnormal conditions, the correction deviation caused by instantaneous abnormalities can be effectively avoided, and the accuracy of the correction model is improved. Even if the sensor measurement value exceeds the normal range, the system can still complete the correction calculation based on the preset variation, avoiding interruption or unreasonable mutation in the correction process, and ensuring the rationality of the actual water temperature value.

[0057] Specifically, in the engine bench or vehicle road test, the water temperature, oil temperature, and EGR coolant temperature are recorded as a function of time under different speeds, loads, and ambient temperatures. Based on the historical data, the temperature variation under the same or similar conditions in the historical data is counted, and the average or median value is taken as the preset variation. For example, under the long-slope retarder condition, the average variation of the EGR coolant temperature is 0.5℃ / s, and this value is set as the replacement value, i.e., the above-mentioned preset variation.

[0058] In another alternative, the method further comprises: in the case that the hydraulic retarder exits the braking condition, and after the hydraulic retarder exits the braking condition for the preset time period, controlling the actual water temperature value of the engine to change to the current water temperature value of the engine at a preset rate.

[0059] In the above embodiments, if the measured value of the sensor is immediately used to replace the model correction value after the hydraulic retarder exits the braking condition, a significant jump in the water temperature signal can occur. This jump can cause the control strategy of the ECU to misjudge, resulting in unnecessary frequent actions of the fan, water pump, torque limiting protection, and the like. By setting a preset rate, the actual water temperature value after correction is smoothly transitioned to the sensor value, which can avoid the problem of sudden change, ensure the continuity of the water temperature signal change process, and avoid the abnormal triggering of the overheat protection strategy caused by unstable signals. Moreover, the smooth change in water temperature can make the engine output more stable, and the driver experience will not be interrupted due to the torque limitation caused by the virtual high or low water temperature. By controlling the corrected water temperature value to gradually return to the sensor measured value at a preset rate after the hydraulic retarder exits the braking condition, the smooth transition of the water temperature signal is achieved, the misjudgment of the control strategy and the frequent actions of the system are avoided, and thus the stability and driving comfort of the engine operation are improved.

[0060] In order for those skilled in the art to more clearly understand the technical solutions of the present application, the implementation process of the engine water outlet temperature correction method of the present application will be described in detail below in conjunction with specific embodiments.

[0061] The present embodiment relates to a specific engine water outlet temperature correction method, as shown in Figure 5 The method comprises the following steps:

[0062] Step S1: Determine whether the hydraulic retarder is in a braking condition. If the hydraulic retarder is in a braking condition, execute step S2. If the hydraulic retarder is not in a braking condition, exit the flow;

[0063] Step S2: Correct the current water temperature value of the engine according to the water temperature model;

[0064] Step S3: Continuously monitor the working condition of the hydraulic retarder and determine whether the hydraulic retarder exits the braking condition. If the hydraulic retarder exits the braking condition, execute step S4. If the hydraulic retarder does not exit the braking condition, execute step S2;

[0065] Step S4: Determine whether the hydraulic retarder exits the braking condition for a preset time length. If the hydraulic retarder exits the braking condition for a preset time length, execute step S5. If the hydraulic retarder exits the braking condition for a preset time length, execute step S2;

[0066] Step S5: Control the actual water temperature value of the engine to change to the current water temperature value of the engine at a preset rate.

[0067] The embodiments of the present application also provide a specific implementation scenario of the engine hydraulic retarder under high-temperature extreme working conditions. In this scenario, the engine oil temperature will rapidly rise and exceed the first preset temperature due to the continuous release of heat by the hydraulic retarder, so that the change in the engine oil temperature can no longer sensitively reflect the actual thermal state of the cooling system. At the same time, the coolant temperature after the EGR cooler is also continuously higher than the second preset temperature, and the real-time measurement value is distorted or delayed due to the thermal saturation effect. At this time, if the engine outlet water temperature is still directly corrected using the engine oil temperature or the EGR coolant temperature, the judgment of the engine outlet water temperature will be deviated, thereby affecting the control strategy of the engine. To solve this problem, a preset change determined based on historical data is used as an alternative parameter. Specifically, a large amount of time series data of the water temperature, the engine oil temperature and the coolant temperature under different working conditions are collected and stored in advance, and typical temperature change rules are obtained through statistical or fitting methods. When it is detected that the engine oil temperature and the EGR coolant temperature are both in abnormal states, the historical data rule matched with the current working condition is automatically called, the preset change corresponding to the historical data rule is used as an alternative value, and the actual water temperature value of the engine is calculated by combining the current water temperature value and the first correction coefficient. Thus, even in the case of abnormal or out-of-limit sensor output, the alternative value can be generated by relying on the historical rule, the correction process can be prevented from being interrupted, and the output of the actual water temperature value can be ensured to be continuous and smooth. In addition, the historical data can accurately reflect the temperature change trend under typical working conditions, and can prevent the distortion of the water temperature caused by instantaneous data abnormality. In the extreme scenarios such as long-time braking of the hydraulic retarder or high-temperature heavy load in summer, the actual water temperature value after correction can still be close to the real thermal state of the engine, and the unreasonable overheat protection triggered by the ECU due to the false high or false low water temperature data can be avoided. With the help of the alternative value mechanism, stable cooling strategies can be maintained under complex working conditions, and the occurrence of speed fluctuations, frequent start and stop of cooling components and unnecessary alarms can be prevented, thereby improving the reliability of the vehicle operation.

[0068] The embodiments of the present application also provide a specific implementation scenario of determining the first correction coefficient according to the current water temperature value of the engine. A heavy truck uses a hydraulic retarder for long-time braking on a downhill road section. At this time, due to the heat generated by braking, the water temperature of the engine will rise. However, due to the position factor, such as being close to the hydraulic retarder or the EGR cooler, the measured water temperature value of the traditional water temperature sensor is higher than the actual water temperature, thereby causing unnecessary intervention of the control system, such as increasing the load of the cooling system, limiting the engine torque, and the like. To solve this problem, first, real-time data from the water temperature sensor is obtained, and a mapping relationship table of water temperature values and correction coefficients is preset based on the actual operation data of the engine. The mapping relationship table summarizes the correction proportion, that is, the correction coefficient, of the engine water temperature when the engine water temperature is affected by the hydraulic retarder in different water temperature value intervals. For example, when the water temperature is low, the correction coefficient can be small, which means that the influence of the water temperature model is small, and the measured value of the water temperature sensor is relatively reliable. As the water temperature rises, the correction coefficient increases, and the correction effect of the model on the measured value also increases accordingly. According to the current water temperature value obtained in real time, the preset mapping relationship table is queried to obtain the correction coefficient corresponding to the current water temperature value as the first correction coefficient. Assuming that the truck is using the hydraulic retarder on a downhill road, the initial water temperature is 85 DEG C, and the correction coefficient corresponding to 85 DEG C is obtained by querying the table, that is, 0.15. The change of the oil temperature is continuously monitored, and assuming that the oil temperature rises by 5 DEG C during the braking of the hydraulic retarder, the corrected water temperature value is calculated to obtain the actual water temperature value, that is, 84.25 DEG C. Through the above method, the corrected water temperature value is closer to the actual water temperature state of the engine, the influence of the additional heat generated by the braking of the hydraulic retarder on the water temperature sensor is avoided, the perception accuracy of the control system to the engine state is improved, and the safety and comfort of driving are also improved.

[0069] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in an order different from that shown herein.

[0070] The embodiments of the present application also provide a correction device for engine outlet water temperature. It should be noted that the correction device for engine outlet water temperature of the embodiments of the present application can be used to execute the correction method for engine outlet water temperature provided by the embodiments of the present application. The device is used to realize the above-mentioned embodiments and preferred embodiments, and will not be described again. As used below, the term "module" can be a combination of software and / or hardware that realizes a predetermined function. Although the device described in the following embodiments is preferably realized in software, the realization of hardware, or a combination of software and hardware, is also possible and conceived.

[0071] The correction device for engine outlet water temperature provided by the embodiments of the present application is described below.

[0072] Figure 6 is a schematic diagram of a correction device for engine outlet water temperature according to an embodiment of the present application. As shown in the figure, the device comprises: Figure 6

[0073] a first acquisition unit 10, configured to acquire a current water temperature value of an engine, the current water temperature value being a measured value of a water temperature sensor in the engine;

[0074] a construction unit 20, configured to construct a water temperature model according to the current water temperature value of the engine and an oil temperature;

[0075] Specifically, the water temperature model is established based on the current water temperature value of the engine and the oil temperature, and the combination of the two can more accurately reflect the thermal state of the engine. However, it should be understood that the water temperature model is not limited to being based on the above parameters, such as the coolant temperature passing through the EGR cooler, the ambient temperature, the engine speed, etc.

[0076] a correction unit 30, configured to correct the current water temperature value of the engine according to the water temperature model when the hydraulic retarder is in a braking condition, or when the hydraulic retarder exits the braking condition and a preset time period has elapsed after the hydraulic retarder exits the braking condition, and to take the corrected water temperature value as the actual water temperature value of the engine.

[0077] Specifically, when the hydraulic retarder is in the braking condition, or when the hydraulic retarder exits the braking condition and a certain preset time period has elapsed after the exit, the actual temperature state of the engine is often affected by the heat conduction of the retarder, resulting in a deviation in the temperature value measured by the water temperature sensor. In view of this situation, the water temperature model is used to correct the current water temperature value collected by the sensor, which can filter out the transient interference introduced by the operation of the retarder, so that the corrected water temperature value is closer to the true thermal state of the engine.

[0078] ​Through the above embodiment, first, the measured value of the water temperature sensor in the engine is obtained by the first acquisition unit as the current water temperature value of the engine, then the water temperature model is constructed by the construction unit according to the current water temperature value of the engine and the oil temperature; finally, the current water temperature value of the engine is corrected according to the water temperature model by the correction unit in the case that the hydraulic retarder is in the braking working condition, or after the hydraulic retarder exits the braking working condition and a preset time period has elapsed since the hydraulic retarder exits the braking working condition, and the corrected water temperature value is taken as the actual water temperature value of the engine. The scheme corrects the engine outlet water temperature collected by the water temperature sensor through the water temperature model in the case that the hydraulic retarder is in the braking working condition or just exits the braking working condition, thereby avoiding the measurement deviation of the sensor caused by the heat exchange effect of the hydraulic retarder, making the water temperature value closer to the real thermal state of the engine, and further improving the stability and reliability of the vehicle operation, and solving the problem that the water temperature sensor reading is too high in the prior art when the hydraulic retarder is in the braking working condition or just exits the braking working condition, thereby causing the error cooling control.

[0079] In an optional solution, the above correction unit comprises: an acquisition module, configured to acquire the above oil temperature, and determine a first change amount of the above oil temperature in a preset time period in the case that the above oil temperature is less than or equal to a first preset temperature; a first determination module, configured to determine a first correction coefficient according to the above current water temperature value of the above engine; and a second determination module, configured to determine the above actual water temperature value of the above engine according to the above first change amount, the above first correction coefficient and the above current water temperature value of the above engine.

[0080] In the above embodiment, the engine water temperature value is corrected by combining the correction coefficient determined by the current water temperature value when the oil temperature is less than or equal to the first preset temperature, the change trend of the oil temperature can reflect the heat accumulation caused by the engine friction and load, and the correlation between the oil temperature and the water temperature is stronger in the low temperature range. The change amount of the oil temperature is used to correct the water temperature value, which can more accurately reflect the real thermal state of the engine cooling system. If the measurement value of the water temperature sensor is simply relied on, deviation is prone to occur in the hydraulic retarder braking and other working conditions. Introducing the change trend of the oil temperature as a comparison and correction basis helps to avoid misjudgment caused by the sensor position or transient interference, and helps the ECU to make more accurate control in the overheat protection aspect, thereby avoiding problems such as excessive torque limiting or abnormal speed fluctuation. Through the combination of the current water temperature value, the positive coefficient and the change amount of the oil temperature, the temperature information of different sources is comprehensively utilized, the adaptability of the system in different working conditions is improved, and good reliability can be maintained when the hydraulic retarder frequently intervenes or the environmental temperature fluctuates greatly.

[0081] Specifically, in the case that the engine oil temperature is less than or equal to the first preset temperature, it indicates that the engine is in a low-temperature working condition, at this time, the fluctuation of the engine oil temperature has a more direct reflection on the thermal state of the engine cooling system. Thus, in this condition, the variation of the engine oil temperature in a preset time period is further determined as an auxiliary variable for water temperature correction. According to the current water temperature value of the engine, a corresponding first correction coefficient is determined. The correction coefficient reflects the sensitivity of the engine oil temperature variation to the water temperature correction at different water temperature levels. The above-mentioned first preset temperature is a threshold value for determining whether the engine oil temperature is in a low-temperature or normal temperature range, which is obtained based on the thermal characteristics of the engine under different operating conditions through experimental calibration and historical data analysis. In the specific implementation process, the corresponding relationship between the engine oil temperature and the engine water temperature variation can be collected in the engine cooling system bench test or vehicle road test, and when the engine oil temperature is lower than a certain value, the change trend has the strongest correlation with the water temperature correction, and this value is used as a reference for the first preset temperature.

[0082] In another optional solution, the above-mentioned device further comprises: a second acquisition unit, configured to acquire the cooling liquid temperature passing through the EGR cooler in the case that the engine oil temperature is greater than the first preset temperature; a first determination unit, configured to determine a second variation of the cooling liquid temperature passing through the EGR cooler in the preset time period in the case that the cooling liquid temperature passing through the EGR cooler is less than or equal to a second preset temperature; and a second determination unit, configured to determine the actual water temperature value of the engine according to the second variation, the first correction coefficient, and the current water temperature value of the engine.

[0083] In the above-mentioned embodiment, when the engine oil temperature exceeds the first preset temperature, the engine oil heat approaches saturation, and the change trend no longer remains consistent with the cooling liquid temperature. At this time, if the correction continues to rely on the variation of the engine oil temperature, the water temperature correction value will be distorted. By introducing the EGR cooling liquid temperature as an alternative reference, the distortion problem caused by the high-temperature saturation of the engine oil temperature can be avoided. The EGR cooler is in the exhaust gas heat exchange path, and the outlet cooling liquid temperature is sensitive to the engine thermal load and cooling efficiency. By extracting the variation of the cooling liquid temperature in the preset time period when the cooling liquid temperature is less than or equal to the second preset temperature, a dynamic quantity highly related to the engine cooling state can be obtained as an input for correction calculation. The actual water temperature value obtained by comprehensively calculating the second variation, the correction coefficient, and the current water temperature value avoids the error caused by the abnormality of a single sensor signal, so that the water temperature correction model is still reliable in the high-temperature working condition and the frequent intervention of the retarder. The corrected actual water temperature value can provide more real temperature information for the ECU, so as to realize more reasonable adjustment in the friction torque calculation, over-temperature protection torque limiting, and the like, and avoid the overwork of the cooling system or the abnormal triggering of the protection strategy caused by the water temperature misjudgment.

[0084] Specifically, when the oil temperature has exceeded the first preset temperature, it indicates that the oil itself is in a high temperature state, and the temperature change rate tends to be slow. At this time, the correlation between the temperature rise of the oil and the water temperature of the cooling system is weakened, and the oil temperature can no longer sensitively reflect the actual change of the cooling liquid temperature, and therefore the cooling liquid temperature passing through the EGR cooler is introduced as a correction basis.

[0085] In some example embodiments, the first determining module includes a first determining sub-module configured to determine, according to the current water temperature value of the engine and a preset mapping relationship table of water temperature values and correction coefficients, that the correction coefficient corresponding to the current water temperature value of the engine is the first correction coefficient, and the water temperature values and the correction coefficients are in one-to-one correspondence.

[0086] In the above embodiments, by establishing the mapping relationship of the water temperature values and the correction coefficients, different correction amplitudes can be set for each temperature interval, so that the correction model can maintain reasonable sensitivity in the low temperature zone and the high temperature zone. Due to the position of the water temperature sensor and the working condition of the retarder, the water temperature measurement deviation is caused, and through the one-to-one mapping relationship, the randomness caused by manual selection or temporary calculation can be avoided. Each water temperature value corresponds to a unique correction coefficient, thereby ensuring the stability of the correction result. In actual operation, only the current water temperature value needs to be read, and the corresponding correction coefficient needs to be found in the mapping table, without the need for complex real-time operation. This way greatly reduces the occupation of computing resources and improves the response speed of the control system.

[0087] The corresponding relationship between the water temperature values and the correction coefficients can be obtained through test calibration and adjusted according to different engine models or application conditions. When the current water temperature value is not in the mapping table, the correction coefficient can be determined through linear interpolation according to the correction coefficients of the adjacent two water temperature values, and the correction coefficient between the two points can be obtained through proportional calculation.

[0088] In other example embodiments, the second determining module includes an obtaining sub-module configured to obtain the product of the first change amount and the first correction coefficient, and a second determining sub-module configured to determine the difference between the current water temperature value of the engine and the product as the actual water temperature value of the engine.

[0089] In the above embodiment, the first change amount reflects the change trend of the engine oil temperature in a certain time period, and can represent the dynamic process of engine heat input; by determining the difference between the current water temperature value of the engine and the product as the actual water temperature value of the engine, the instantaneous interference caused by the hydraulic retarder braking or local uneven heat dissipation can be effectively filtered out, the sensitivity of the model to small amplitude temperature changes is improved, the ECU can more timely and accurately identify the real change of the water temperature, and the amplification effect of single point data anomaly is avoided, thereby ensuring that the correction result is more stable, further providing data support for overheat protection and other strategies, and avoiding the problem of triggering false cooling control.

[0090] Specifically, the actual water temperature value of the engine is determined according to Q1=Q2-|△r|×k, wherein Q1 is the actual water temperature value of the engine, Q2 is the current water temperature value of the engine, k is the first correction coefficient, and△r is the first change amount.

[0091] In an optional solution, the correction unit further comprises a third determination module configured to, in a case where the coolant temperature passing through the EGR cooler is greater than the second preset temperature, determine the actual water temperature value of the engine according to a preset change amount, the first correction coefficient, and the current water temperature value of the engine, wherein the preset change amount is determined based on historical data.

[0092] In the above embodiment, by introducing the preset change amount determined based on historical data to correct the water temperature in the case where the coolant temperature at the outlet of the EGR cooler is greater than the second preset temperature, the preset change amount established based on the historical data is used as a replacement parameter when the EGR coolant temperature is too high, and a reliable reference is provided when real-time data is distorted or unavailable. The historical data is derived from long-term collection of the engine under different operating conditions, and can better reflect the typical temperature change trend. By introducing historical data under abnormal conditions, the correction deviation caused by instantaneous abnormalities can be effectively avoided, and the accuracy of the model correction is improved. Even if the sensor measurement value exceeds the normal range, the system can still complete the correction calculation based on the preset change amount, avoids interruption or unreasonable mutation in the correction process, and ensures the rationality of the actual water temperature value.

[0093] Specifically, in the engine bench or vehicle road test, the change trends of the water temperature, the engine oil temperature, and the EGR coolant temperature with time under different speeds, loads, and ambient temperatures are recorded, and the average value or the median value is taken as the preset change amount by statistically analyzing the temperature changes under the same or similar conditions based on the historical data. For example, under the long slope retarder working condition, the average change amount of the EGR coolant temperature is 0.5℃ / s, and the value is set as the replacement amount, i.e., the preset change amount.

[0094] In another alternative, the device further comprises a control unit configured to control the actual water temperature value of the engine to change to the current water temperature value of the engine at a preset rate if the hydraulic retarder exits the braking condition and a preset time period has elapsed after the hydraulic retarder exits the braking condition.

[0095] In the above embodiment, if the measured value of the sensor is used to replace the model correction value immediately after the hydraulic retarder exits the braking condition, a significant jump in the water temperature signal may occur. This jump may cause the ECU control strategy to be misjudged, resulting in unnecessary frequent actions of the fan, water pump, torque limiting protection, and the like. By setting a preset rate, the corrected actual water temperature value is smoothly transitioned to the sensor value, which can avoid the problem of sudden change, ensure the continuity of the water temperature signal change process, and avoid the abnormal triggering of the overheat protection strategy due to unstable signals. In addition, the smooth change in water temperature can make the engine output more stable, and the driver's experience will not be interrupted due to the torque limitation caused by the virtual high or low water temperature. By controlling the corrected water temperature value to gradually return to the measured value of the sensor at a preset rate after the hydraulic retarder exits the braking condition, the smooth transition of the water temperature signal is achieved, the misjudgment of the control strategy is avoided, and the system is not frequently activated, thereby improving the stability of the engine operation and the driving comfort.

[0096] The engine outlet water temperature correction device includes a processor and a memory, and the first acquisition unit, the construction unit, and the correction unit are all stored in the memory as program units. The corresponding functions are realized by the processor executing the program units stored in the memory. The modules are located in the same processor, or the modules are located in different processors in any combination.

[0097] The processor includes a core, and the core retrieves the corresponding program unit from the memory. The core can be set to one or more, and the core parameters are adjusted to at least solve the problem of false reading of the water temperature sensor and triggering of the error cooling control when the hydraulic retarder is in the braking condition or has just exited the braking condition in the prior art.

[0098] The memory can include a non-persistent memory in a computer readable medium, a random access memory (RAM), and / or a non-volatile memory such as a read-only memory (ROM) or a flash memory (flash RAM), and the memory includes at least one memory chip.

[0099] The embodiment of the present application provides a computer readable storage medium, and the computer readable storage medium includes a stored program. When the program runs, the computer readable storage medium controls the device where the computer readable storage medium is located to execute the engine outlet water temperature correction method.

[0100] Specifically, the correction method of the engine water outlet temperature comprises:

[0101] In step S101, a current water temperature value of the engine is obtained, the current water temperature value being a measured value of a water temperature sensor in the engine;

[0102] In step S102, a water temperature model is constructed according to the current water temperature value of the engine and an oil temperature;

[0103] Specifically, the water temperature model is constructed with the current water temperature value of the engine and the oil temperature as core parameters, and the combination of the two can more accurately reflect the thermal state of the engine. However, it should be understood that the water temperature model is not limited to being based on the above parameters, such as the coolant temperature passing through the EGR cooler, the ambient temperature, the engine speed, etc.

[0104] In step S103, when the hydraulic retarder is in a braking condition, or when the hydraulic retarder exits the braking condition and a preset time period has elapsed after the hydraulic retarder exits the braking condition, the current water temperature value of the engine is corrected according to the water temperature model, and the corrected water temperature value is taken as the actual water temperature value of the engine.

[0105] Specifically, when the hydraulic retarder is in a braking condition, or when the hydraulic retarder exits the braking condition and a certain preset time period has elapsed after the exit, the actual temperature state of the engine is often affected by the heat conduction of the retarder, resulting in a deviation in the temperature value measured by the water temperature sensor. In view of this situation, the current water temperature value collected by the sensor is corrected using the water temperature model, which can filter out the transient interference introduced by the operation of the retarder, so that the corrected water temperature value is closer to the true thermal state of the engine.

[0106] In an embodiment of the present application, the current water temperature value of the engine is corrected according to the water temperature model, and the corrected water temperature value is taken as the actual water temperature value of the engine, comprising: obtaining the oil temperature, determining a first change amount of the oil temperature in a preset time period when the oil temperature is less than or equal to a first preset temperature; determining a first correction coefficient according to the current water temperature value of the engine; determining the actual water temperature value of the engine according to the first change amount, the first correction coefficient and the current water temperature value of the engine.

[0107] In an embodiment of the present application, the method further comprises: in the case that the oil temperature is greater than the first preset temperature, obtaining a coolant temperature passing through the EGR cooler; in the case that the coolant temperature passing through the EGR cooler is less than or equal to a second preset temperature, determining a second variation of the coolant temperature in the preset time period; and determining the actual water temperature value of the engine according to the second variation, the first correction coefficient and the current water temperature value of the engine.

[0108] In an embodiment of the present application, the first correction coefficient is determined according to the current water temperature value of the engine, comprising: determining the correction coefficient corresponding to the current water temperature value of the engine as the first correction coefficient according to the current water temperature value of the engine and a preset mapping relationship table of water temperature values and correction coefficients, wherein the water temperature values and the correction coefficients are in one-to-one correspondence.

[0109] In an embodiment of the present application, the actual water temperature value of the engine is determined according to the first variation, the first correction coefficient and the current water temperature value of the engine, comprising: obtaining a product of the first variation and the first correction coefficient; and determining the difference between the current water temperature value of the engine and the product as the actual water temperature value of the engine.

[0110] In an embodiment of the present application, the method further comprises: in the case that the coolant temperature passing through the EGR cooler is greater than the second preset temperature, determining the actual water temperature value of the engine according to a preset variation, the first correction coefficient and the current water temperature value of the engine, wherein the preset variation is determined based on historical data.

[0111] In an embodiment of the present application, the method further comprises: in the case that the hydraulic retarder exits the braking working condition and a preset time period elapses after the hydraulic retarder exits the braking working condition, controlling the actual water temperature value of the engine to change to the current water temperature value of the engine at a preset rate.

[0112] An embodiment of the present application provides an engine water outlet temperature correction system, comprising a processor, a memory, and a program stored in the memory and executable on the processor, and at least the following steps are implemented when the processor executes the program:

[0113] Step S101: obtaining a current water temperature value of an engine, wherein the current water temperature value is a measurement value of a water temperature sensor in the engine;

[0114] Step S102: constructing a water temperature model according to the current water temperature value of the engine and an oil temperature;

[0115] Specifically, the water temperature model is established based on the current water temperature value of the engine and the oil temperature, and the combination of the two can accurately reflect the thermal state of the engine. However, it should be understood that the water temperature model is not limited to the above-mentioned parameters, such as the coolant temperature passing through the EGR cooler, the ambient temperature, the engine speed, etc.

[0116] In step S103, when the hydraulic retarder is in the braking working condition, or when the hydraulic retarder exits the braking working condition and a preset time period has elapsed after the hydraulic retarder exits the braking working condition, the current water temperature value of the engine is corrected according to the water temperature model, and the corrected water temperature value is taken as the actual water temperature value of the engine.

[0117] Specifically, when the hydraulic retarder is in the braking working condition, or when the hydraulic retarder exits the braking working condition and a certain preset time period has elapsed after the exit, the actual temperature state of the engine is often affected by the heat conduction of the retarder, resulting in deviation of the temperature value measured by the water temperature sensor. For this situation, the water temperature model is used to correct the current water temperature value collected by the sensor, which can filter out the transient interference introduced by the working of the retarder, so that the corrected water temperature value is closer to the true thermal state of the engine.

[0118] The device herein can be a server, a PC, a PAD, a mobile phone, etc.

[0119] In an embodiment of the present application, the current water temperature value of the engine is corrected according to the water temperature model, and the corrected water temperature value is taken as the actual water temperature value of the engine, including: obtaining the oil temperature, and determining a first change amount of the oil temperature in a preset time period when the oil temperature is less than or equal to a first preset temperature; determining a first correction coefficient according to the current water temperature value of the engine; and determining the actual water temperature value of the engine according to the first change amount, the first correction coefficient, and the current water temperature value of the engine.

[0120] In an embodiment of the present application, the method further includes: obtaining the coolant temperature passing through the EGR cooler when the oil temperature is greater than the first preset temperature; determining a second change amount of the coolant temperature passing through the EGR cooler in the preset time period when the coolant temperature passing through the EGR cooler is less than or equal to a second preset temperature; and determining the actual water temperature value of the engine according to the second change amount, the first correction coefficient, and the current water temperature value of the engine.

[0121] In an embodiment of the present application, the first correction coefficient is determined according to the current water temperature value of the engine, comprising: determining the correction coefficient corresponding to the current water temperature value of the engine as the first correction coefficient according to the current water temperature value of the engine and a preset mapping relationship table of water temperature values and correction coefficients, wherein the water temperature values and the correction coefficients are in one-to-one correspondence.

[0122] In an embodiment of the present application, the actual water temperature value of the engine is determined according to the first change amount, the first correction coefficient and the current water temperature value of the engine, comprising: obtaining a product of the first change amount and the first correction coefficient; and determining a difference between the current water temperature value of the engine and the product as the actual water temperature value of the engine.

[0123] In an embodiment of the present application, the method further comprises: in the case that the coolant temperature passing through the EGR cooler is greater than the second preset temperature, determining the actual water temperature value of the engine according to a preset change amount, the first correction coefficient and the current water temperature value of the engine, wherein the preset change amount is determined based on historical data.

[0124] In an embodiment of the present application, the method further comprises: in the case that the hydraulic retarder exits the braking working condition and after the hydraulic retarder exits the braking working condition for the preset time length, controlling the actual water temperature value of the engine to change to the current water temperature value of the engine at a preset rate.

[0125] Obviously, those skilled in the art should understand that each module or each step of the present application described above can be realized by a general computing device, which can be centralized on a single computing device or distributed on a network composed of multiple computing devices, and can be realized by program codes executable by a computing device, so that each module or each step can be stored in a storage device and executed by a computing device, and in some cases, the steps shown or described can be executed in different orders, or each module or step can be manufactured as an individual integrated circuit module or multiple modules or steps can be manufactured as a single integrated circuit module. Therefore, the present application is not limited to any specific combination of hardware and software.

[0126] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can be in the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Moreover, the present application can be in the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0127] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.

[0128] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.

[0129] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.

[0130] In one typical configuration, the computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0131] The memory can include non-persistent memory and / or persistent memory, such as flash memory, read-only memory (ROM), and / or volatile or non-volatile random access memory (RAM), among others. The memory is an example of computer readable media.

[0132] Computer-readable media includes permanent and non-permanent, movable and non-movable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible by a computing device. According to the definition herein, computer-readable media does not include transitory media such as modulated data signals and carriers.

[0133] The technical features of the above-described embodiments can be combined in any manner. In order to make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not exist contradictions, it should be considered as the scope of the present disclosure.

[0134] It should also be noted that the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles or devices including a series of elements not only include those elements, but also include other elements not explicitly listed, or inherent to such processes, methods, articles or devices. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0135] From the above description, it can be seen that the above-described embodiments of the present application achieve the following technical effects:

[0136] 1) The engine outlet water temperature correction method of the application first obtains the measurement value of the water temperature sensor in the engine as the current water temperature value of the engine, then constructs a water temperature model according to the current water temperature value of the engine and the oil temperature; in the case that the hydraulic retarder is in the braking working condition, or in the case that the hydraulic retarder exits the braking working condition and a preset time period has elapsed after the hydraulic retarder exits the braking working condition, the current water temperature value of the engine is corrected according to the water temperature model, and the corrected water temperature value is taken as the actual water temperature value of the engine. The scheme corrects the engine outlet water temperature collected by the water temperature sensor through the water temperature model in the case that the hydraulic retarder is in the braking working condition or just exits the braking working condition, thereby avoiding the measurement deviation of the sensor caused by the heat exchange effect of the hydraulic retarder, making the water temperature value closer to the real thermal state of the engine, and further improving the stability and reliability of the vehicle operation, solving the problem of false high reading of the water temperature sensor in the prior art when the hydraulic retarder is in the braking working condition or just exits the braking working condition, which leads to the triggering of false cooling control.

[0137] 2) The engine outlet water temperature correction device of the application first obtains the measurement value of the water temperature sensor in the engine as the current water temperature value of the engine through the first obtaining unit, then constructs a water temperature model according to the current water temperature value of the engine and the oil temperature through the constructing unit; finally, the current water temperature value of the engine is corrected according to the water temperature model through the correcting unit in the case that the hydraulic retarder is in the braking working condition, or in the case that the hydraulic retarder exits the braking working condition and a preset time period has elapsed after the hydraulic retarder exits the braking working condition, and the corrected water temperature value is taken as the actual water temperature value of the engine. The scheme corrects the engine outlet water temperature collected by the water temperature sensor through the water temperature model in the case that the hydraulic retarder is in the braking working condition or just exits the braking working condition, thereby avoiding the measurement deviation of the sensor caused by the heat exchange effect of the hydraulic retarder, making the water temperature value closer to the real thermal state of the engine, and further improving the stability and reliability of the vehicle operation, solving the problem of false high reading of the water temperature sensor in the prior art when the hydraulic retarder is in the braking working condition or just exits the braking working condition, which leads to the triggering of false cooling control.

[0138] The above only describes the preferred embodiments of the application and is not intended to limit the application. Those skilled in the art can make various changes and modifications to the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. A method for correcting engine outlet water temperature, characterized in that, include: The current coolant temperature of the engine is obtained, wherein the current coolant temperature is the measurement value of the coolant temperature sensor in the engine; A water temperature model is constructed based on the current water temperature and oil temperature of the engine. When the hydraulic retarder is in braking condition, or when the hydraulic retarder has exited braking condition and a preset time has elapsed since then, the current water temperature value of the engine is corrected according to the water temperature model, and the corrected water temperature value is taken as the actual water temperature value of the engine.

2. The method according to claim 1, characterized in that, The engine's current water temperature value is corrected according to the water temperature model, and the corrected water temperature value is used as the engine's actual water temperature value, including: The engine oil temperature is obtained, and when the engine oil temperature is less than or equal to a first preset temperature, a first change in the engine oil temperature over a preset time period is determined. A first correction factor is determined based on the current coolant temperature of the engine; The actual water temperature of the engine is determined based on the first change, the first correction factor, and the current water temperature of the engine.

3. The method according to claim 2, characterized in that, The method further includes: When the engine oil temperature is greater than the first preset temperature, the coolant temperature after passing through the EGR cooler is obtained; If the temperature of the coolant passing through the EGR cooler is less than or equal to a second preset temperature, a second change in the coolant temperature within the preset time period is determined. The actual water temperature of the engine is determined based on the second change, the first correction coefficient, and the current water temperature of the engine.

4. The method according to claim 2, characterized in that, Based on the current coolant temperature of the engine, a first correction factor is determined, including: Based on the current water temperature value of the engine and the preset mapping table between water temperature value and correction coefficient, the correction coefficient corresponding to the current water temperature value of the engine is determined to be the first correction coefficient, and the water temperature value and the correction coefficient are in one-to-one correspondence.

5. The method according to claim 2, characterized in that, Determining the actual coolant temperature of the engine based on the first change, the first correction coefficient, and the current coolant temperature of the engine includes: Obtain the product of the first change and the first correction coefficient; The difference between the current water temperature value of the engine and the product is determined as the actual water temperature value of the engine.

6. The method according to claim 3, characterized in that, The method further includes: If the coolant temperature after passing through the EGR cooler is greater than the second preset temperature, the actual coolant temperature of the engine is determined based on the preset change amount, the first correction coefficient, and the current coolant temperature of the engine. The preset amount of change is determined based on historical data.

7. The method according to claim 1, characterized in that, The method further includes: When the hydraulic retarder exits the braking condition, and after the preset time elapses following the exit of the hydraulic retarder from the braking condition, the actual coolant temperature of the engine is controlled to change at a preset rate to the current coolant temperature of the engine.

8. A device for correcting engine outlet water temperature, characterized in that, include: An acquisition unit is used to acquire the current coolant temperature value of the engine, wherein the current coolant temperature value is the measurement value of the coolant temperature sensor in the engine; A construction unit is used to construct a water temperature model based on the current water temperature value and oil temperature of the engine. The correction unit is used to correct the current water temperature value of the engine according to the water temperature model when the hydraulic retarder is in braking condition, or when the hydraulic retarder is out of braking condition and a preset time has elapsed after the hydraulic retarder is out of braking condition, and to use the corrected water temperature value as the actual water temperature value of the engine.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the method according to any one of claims 1 to 7.

10. A correction system for engine outlet water temperature, characterized in that, include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs comprising methods for performing any one of claims 1 to 7.

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