Engine oil temperature estimation method and device, electronic equipment and storage medium

Abstract

The invention discloses an engine oil temperature estimation method and device, electronic equipment and a storage medium, and is applied to the field of automobiles. According to the engine oil temperature estimation method and device, the current running state of an engine is obtained firstly, the running state comprises the shutdown state, the engine warming state and the engine heating state, then the method for estimating the engine oil temperature is determined based on the running state, the method for estimating the engine oil temperature comprises target factors, and the target factors are determined according to the running state. And finally, estimating the engine oil temperature by using the method. The invention further discloses a device for estimating the engine oil temperature. The accuracy of estimating the engine oil temperature of the engine is improved.

Description

Technical Field

[0001] The present application relates to the field of automobile technology, and in particular to a method, device, electronic device and storage medium for estimating engine oil temperature. Background Art

[0002] In the engine electronic control module, the oil temperature is used as a signal input for the enable control of the variable valve timing system, the control of the cooling and heating machine switching, etc., which plays a role in reducing harmful pollutants. At the same time, the oil temperature has an important impact on the working performance of the engine. Accurate estimation of the oil temperature is important for maintaining the normal operation of the engine. However, the method for determining the oil temperature in the prior art cannot accurately estimate the oil temperature of the engine. Summary of the invention

[0003] In view of this, embodiments of the present application provide a method, device, electronic device and storage medium for estimating engine oil temperature, aiming to improve the accuracy of estimating the engine oil temperature.

[0004] In a first aspect, an embodiment of the present application provides a method for estimating engine oil temperature, the method comprising:

[0005] Obtaining the current operating state of the engine, wherein the operating state includes shutdown, warm-up and hot state;

[0006] a method for determining an estimated engine oil temperature based on the operating state, the method for estimating the engine oil temperature comprising a target factor, the target factor being determined based on the operating state;

[0007] The method is used to estimate the engine oil temperature.

[0008] Optionally, the method for determining the estimated oil temperature based on the operating state includes:

[0009] When the operating state is a shutdown state, determining the target factor to be the ambient temperature and the engine water temperature;

[0010] Acquiring the ambient temperature and the engine water temperature;

[0011] determining a decay rate of engine oil temperature based on the ambient temperature and the engine water temperature;

[0012] The method for determining the estimated oil temperature is calculated based on the ambient temperature, the engine water temperature and the decay rate.

[0013] Optionally, the method for determining the estimated oil temperature based on the operating state includes:

[0014] When the operating state is a warm-up state, the target factors are determined to be the engine speed, the number of engine revolutions and the oil temperature at the start time, and the oil temperature at the start time is related to the engine water temperature, the decay rate and the ambient temperature;

[0015] Calibrate the delay number of revolutions, which is the number of engine revolutions at the moment when the oil pan temperature rises when the temperature is lower than a preset temperature;

[0016] The method for determining the estimated oil temperature is to calculate it using the engine speed, the number of engine running circles, the oil temperature at the start time and the number of delay circles.

[0017] Optionally, the method for determining the estimated oil temperature based on the operating state includes:

[0018] When the operating state is a hot engine state, determining the target factors as vehicle speed, engine speed, intake pressure, engine water temperature and intake temperature;

[0019] Calibrate the coefficient of vehicle speed, the coefficient of engine water temperature and the coefficient of intake air temperature;

[0020] The method for determining the estimated oil temperature is to calculate it using the engine speed, the number of engine running circles, the oil temperature at the start time, the number of delay circles, the coefficient of the vehicle speed, the coefficient of the engine water temperature and the coefficient of the intake temperature.

[0021] Optionally, determining the decay rate of the oil temperature based on the ambient temperature and the engine water temperature includes:

[0022] Under different ambient temperatures, heating the engine oil until the engine oil reaches a target temperature value;

[0023] When the engine oil reaches a target engine oil temperature value, cooling the engine oil;

[0024] During the cooling operation, the decay rate of the engine oil is calibrated to obtain a decay rate variation table, wherein the decay rate variation table includes a corresponding relationship between the ambient temperature, the engine water temperature and the decay rate;

[0025] The decay rate of the engine oil temperature under the current ambient temperature and engine water temperature is determined based on the decay rate change table.

[0026] Optionally, the calibrating the delay turns includes:

[0027] Heating the engine oil, which circulates in the main oil gallery and the oil pan;

[0028] determining whether the oil pan generates heat exchange with the engine oil;

[0029] If yes, determining the time when the oil pan and the engine oil generate heat exchange to achieve temperature rise;

[0030] Obtaining the number of engine running revolutions at the moment when the temperature starts to rise;

[0031] The engine running number of revolutions is used as the delay number of revolutions to complete the calibration of the delay number of revolutions.

[0032] Optionally, the estimating the engine oil temperature by using the method includes:

[0033] Method for obtaining estimated engine oil temperature;

[0034] Obtaining target parameter values ​​included in the method;

[0035] The engine oil temperature is estimated based on the target parameter value.

[0036] In a second aspect, an embodiment of the present application provides a device for estimating engine oil temperature, the device comprising: an acquisition module, a determination module and an estimation module;

[0037] The acquisition module is used to acquire the current operating state of the engine, wherein the operating state includes shutdown, warm-up and hot state;

[0038] The determination module is used to determine a method for estimating the oil temperature based on the operating state, the method for estimating the oil temperature includes a target factor, and the target factor is determined according to the operating state;

[0039] The estimation module is used to estimate the engine oil temperature using the method.

[0040] In a third aspect, the present application provides an electronic device, the device comprising: a processor, a memory, and a system bus;

[0041] The processor and the memory are connected via the system bus;

[0042] The memory is used to store one or more programs, and the one or more programs include instructions, which, when executed by the processor, enable the processor to execute the method described in the first aspect.

[0043] In a fourth aspect, an embodiment of the present application provides a computer storage medium, in which a code is stored. When the code is executed, a device executing the code implements any method described in the first aspect.

[0044] The present application provides a method, device, electronic device and storage medium for estimating engine oil temperature. When executing the method, first obtain the current operating state of the engine, the operating state includes shutdown, warm-up and hot state, then determine the target factor corresponding to the operating state according to the operating state, and determine the method for estimating the engine oil temperature based on the target factor. Finally, use the method to estimate the engine oil temperature. In this way, by determining different target factors according to the different operating states of the engine, and setting the engine oil estimation method according to different target factors, it is possible to flexibly adjust the method for estimating the engine oil temperature according to the different operating states of the engine, so that the temperature estimation is more accurate, and the influence of different environments on the engine oil temperature is fully considered, so that the engine oil temperature estimation is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in this embodiment or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 A flow chart of a method for estimating engine oil temperature provided in an embodiment of the present application;

[0047] Figure 2 A schematic diagram of engine state change provided in an embodiment of the present application;

[0048] Figure 3 A schematic diagram of the structure of an oil temperature estimation device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] In this application, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0051] In the study of related technologies, it was found that the existing oil temperature calculation method assumes that the heating rate during the engine warm-up process is equal to the oil temperature decay rate when the engine is stopped. This method ignores the direct impact of the heat released by combustion in the engine cylinder on the oil temperature. In addition, the existing oil temperature calculation method ignores the oil temperature decay when the engine is stopped during the vehicle's driving process, and uses the engine water temperature as the base value of the oil temperature. This method easily leads to an abnormal increase in the estimated oil temperature during the engine stop process, which does not conform to physical logic.

[0052] Based on this, the present application proposes a method, device, electronic device and storage medium for estimating engine oil temperature, which can truly reflect the engine oil temperature that meets the engine operating state, so as to achieve the effect of estimating the engine oil temperature with lower cost and higher accuracy.

[0053] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0054] Figure 1 A flowchart of a method for estimating engine oil temperature provided in an embodiment of the present application, see Figure 1 As shown, a method for estimating engine oil temperature provided by an embodiment of the present application includes:

[0055] S11: Acquire the current operating state of the engine, which includes shutdown, warm-up and hot state.

[0056] Engine warm-up can be understood as engine preheating, which means starting the engine first so that the engine can be better lubricated and enter the best working state.

[0057] The engine is hot and the engine reaches its normal operating temperature, at which point the engine reaches its optimal operating state.

[0058] The engine shutdown can be understood as a state where the engine is not started.

[0059] Figure 2 A schematic diagram of an engine state change provided in an embodiment of the present application, specifically as follows Figure 2 As shown, first, it can include a cycle from engine start to hot engine state, then from hot engine state to shutdown state, and finally from shutdown state back to engine start. It can also include a cycle from engine start to warm engine state, then from warm engine state to hot engine state, then from hot engine state to shutdown state, and finally from shutdown state back to engine start. It can also include a cycle from engine start to warm engine state, then from warm engine state directly to shutdown state, and finally from shutdown state back to engine start.

[0060] The current oil temperature calculation method includes an initial value calculation step, a final value calculation step, a filter time constant calculation step, and a filter function implementation step. The initial value calculation is to collect multiple sets of engine downtime and downtime oil temperature data according to the difference between the measured water temperature and the intake temperature when the engine is started, and calibrate the initial oil temperature. The final value calculation is to calculate the maximum value that the oil temperature can reach under fixed working conditions. The filter time constant calculation is to calculate the oil temperature change rate. The filter function is implemented by substituting the calculated values ​​of the first three steps into the real-time oil temperature formula obtained by mathematical modeling to calculate the real-time oil temperature value. From the above description, it can be seen that this method ignores the direct effect of combustion heat release in the engine cylinder on the oil temperature. In addition, the existing oil temperature calculation method ignores the decay of the oil temperature when the engine is stopped during the driving of the whole vehicle, so that the engine water temperature is used as the basic value of the oil temperature. This method easily leads to an abnormal increase in the estimated oil temperature during the engine shutdown process, which does not conform to physical logic.

[0061] S12: Determine a method for estimating the engine oil temperature based on the operating state, wherein the method for estimating the engine oil temperature includes a target factor, and the target factor is determined according to the operating state.

[0062] Step S12 mentions "determining the target factor corresponding to the operating state according to the operating state". It can be understood that the target factors corresponding to the three different operating states of the above-mentioned engine are not the same, so it is necessary to determine the target factors under different states, rather than applying the same standard to different operating states. In this way, flexible and adaptive measurement of engine temperature under different states can be achieved, thereby improving the accuracy and pertinence of the measurement results.

[0063] According to different target factors under different operating states, the corresponding methods for estimating the oil temperature are also different. For example, in this embodiment, the engine states include three states, namely shutdown, warm-up and hot state. The factors that affect the oil temperature corresponding to the above different operating states are different. Therefore, it is necessary to design the method for estimating the oil temperature according to the different influencing factors.

[0064] S13: using the method to estimate the engine oil temperature.

[0065] Step S13 may specifically include: first obtaining a method for estimating the engine oil temperature; then obtaining a target parameter value included in the method; and finally estimating the engine oil temperature based on the target parameter value.

[0066] In this embodiment, a method for estimating the oil temperature is proposed. The method first obtains the current operating state of the engine, which includes shutdown, warm-up and hot engine states, and then determines the target factor corresponding to the operating state according to the operating state, and determines the method for estimating the oil temperature based on the target factor. Finally, the method is used to estimate the oil temperature. In this way, by determining different target factors according to different operating states of the engine, and setting the oil estimation method according to different target factors, it is possible to flexibly adjust the oil temperature estimation method according to different operating states of the engine, so that the temperature estimation is more accurate, and the influence of different environments on the oil temperature is fully considered, so that the oil temperature estimation is more accurate.

[0067] In the above-mentioned S12 and S13, it is mentioned that "determine the target factor corresponding to the operating state according to the operating state; determine the method of estimating the oil temperature based on the target factor". Specifically, it can be understood as:

[0068] When the engine is determined to be in a shutdown state, that is, the vehicle is powered on and the engine is not started, the target factor can be determined as the current ambient temperature and the engine water temperature to calculate the oil temperature. Based on the above-determined target factors, the method for determining the estimated oil temperature can be determined as: determining according to the current ambient temperature, the engine water temperature and the decay rate of the above two temperatures.

[0069] The method for determining the decay rate may be: first, heating the engine oil at different ambient temperatures until the engine oil reaches a target temperature value; when the engine oil reaches the target engine oil temperature value, cooling the engine oil. Then, during the cooling operation, the decay rate of the engine oil is calibrated to obtain a decay rate variation table, wherein the decay rate variation table includes a corresponding relationship between the ambient temperature, the engine water temperature, and the decay rate. Finally, the decay rate of the engine oil temperature at the current ambient temperature and the engine water temperature is determined based on the decay rate variation table.

[0070] The determination of the ambient temperature and the engine temperature can be performed using a thermometer or a temperature sensor. The specific method for obtaining the ambient temperature and the engine water temperature can be determined by a technician in the field according to the actual situation and is not limited here. The method for obtaining the decay rate can be determined by a two-dimensional table of changes in the engine water temperature and the ambient temperature, and the table can be calibrated in winter and summer experiments. Under different ambient temperatures, the engine oil temperature is heated to the maximum value that can be reached, and then the engine is stopped for cooling to complete the decay rate calculation at each point.

[0071] The specific method for estimating the oil temperature when the engine is stopped can be done using the following formula:

[0072] Estimated shutdown oil temperature = engine water temperature + decay rate * (engine water temperature – ambient temperature).

[0073] When it is determined that the engine is in a warm-up state, that is, after the engine is started, if the oil temperature has not reached the hot engine temperature threshold. At this time, the target factors can be determined as the engine speed, the number of engine revolutions, and the oil temperature at the start time. The estimated temperature of the warm-up oil can be understood as the temperature range before the thermal equilibrium temperature is reached after the engine is started. The thermal equilibrium temperature can be calibrated by winter and summer experiments. When the engine water temperature reaches equilibrium, the oil temperature change gradually decreases and approaches equilibrium, and the current oil can be regarded as reaching thermal equilibrium.

[0074] The number of engine revolutions mentioned above can be calculated through a mathematical model. Specifically, the number of revolutions increases by one for each revolution of the crankshaft until the maximum number of revolutions is reached. The maximum number of revolutions can be set as a calibration constant. In winter and summer tests, the final number of revolutions is obtained by heating the oil temperature from the lowest temperature to the thermal equilibrium temperature, and the maximum value of multiple sets of test data is taken to obtain the maximum number of revolutions.

[0075] In the warm-up state, the delay number of revolutions can also be used as a factor affecting the engine oil temperature. The delay number of revolutions is a calibration constant. The principle is that when the engine is started after being soaked for a long time, the oil in the main oil gallery is heated first, and the oil circulates in the main oil gallery and the oil pan, causing the oil pan temperature to gradually rise. Therefore, relative to the main oil gallery temperature, the oil pan temperature rises later than the main oil gallery temperature. In a low temperature environment, observe the number of engine running revolutions when the oil pan temperature rises, and this number of revolutions is regarded as the delay number of revolutions.

[0076] The method for determining the number of delay revolutions may specifically be: firstly, heating the engine oil, and the engine oil circulates in the main oil channel and the oil pan. Then, determining whether the oil pan has heat exchange with the engine oil; if so, determining the time when the temperature of the engine oil starts to rise after the heat exchange between the oil pan and the engine oil. Finally, obtaining the number of engine revolutions at the time when the temperature starts to rise; using the number of engine revolutions as the number of delay revolutions, and completing the calibration of the number of delay revolutions.

[0077] In addition, in the warm-up state, the heating coefficient can also be used as a factor affecting the oil temperature. The heating coefficient is a two-dimensional table with the input of the engine speed and the oil temperature at the previous moment. This coefficient represents the rate of change of the oil temperature at different speeds. In winter and summer experiments, the engine is heated with the maximum load and the minimum load at each speed to obtain the steady-state heating coefficient, and then the heating coefficient is adjusted through the endurance test simulation so that it can cover transient conditions.

[0078] The specific method for estimating the oil temperature when the engine is warm can be done using the following formula:

[0079] Estimated warm-up oil temperature = (engine running number of revolutions – delay number of revolutions) * heating coefficient + oil temperature at start-up.

[0080] When the engine is determined to be in a hot state, the oil temperature is in a state of thermal equilibrium, in which the temperature will not rise or fall significantly. At this time, the target factors can be determined as vehicle speed, engine speed, intake pressure, engine water temperature and intake temperature. When the temperature reaches the hot temperature threshold, it indicates that the oil temperature is in a state of thermal equilibrium. The calculation of the model estimate includes two parts: heating source and heat dissipation source. The main heating source factors are engine speed, engine water temperature and intake temperature; the main heat dissipation source factor is vehicle speed, and all factors are combined using a four-element quadratic fitting formula. Among them, engine water temperature, intake temperature and vehicle speed are regarded as univariate factors; engine speed is regarded as a univariate quadratic factor, and is calculated in combination with intake pressure.

[0081] The specific method for estimating the oil temperature when the engine is hot can be used using the following formula:

[0082] Estimated temperature of hot engine oil = vehicle speed * coefficient 1 + speed ^ 2 * coefficient 2 + speed * coefficient 3 + engine water temperature * coefficient 4 + intake temperature * coefficient 5.

[0083] Among them, coefficient 1, coefficient 4 and coefficient 5 are calibration constants. Coefficient 2 and coefficient 3 are one-dimensional tables, and the input is the intake pressure, covering the maximum intake pressure range that the engine can reach. First, through bench experiments, based on different intake temperatures and water temperatures, the engine speed and load are changed, and the speed coefficient 2 and speed coefficient 3 of different loads (intake pressure) are calculated using a nonlinear regression mathematical model. After that, through hub rotation, summer and winter tests, balance experiments are carried out under different vehicle speeds, engine water temperatures and intake temperatures. All data are fitted through a nonlinear regression mathematical model to calculate coefficient 1, coefficient 4 and coefficient 5. The fitting results should be consistent with physical logic. The heat dissipation source speed coefficient 1 is a negative value, and the heating source engine speed coefficients 1 and 2, engine water temperature coefficient 4, and intake temperature coefficient 5 are positive values.

[0084] The speed and oil temperature have a quadratic nonlinear relationship. The higher the speed, the faster the oil temperature rises, and the lower the speed, the slower the oil temperature rises. By determining the speed coefficient under different intake pressures, the speed and the combination of different speed coefficients can be used to estimate the oil temperature.

[0085] The above content can be used to obtain a method for estimating the corresponding oil temperature under different engine conditions.

[0086] Figure 3 A schematic diagram of a device for estimating engine oil temperature provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, a device for estimating engine oil temperature specifically includes: an acquisition module 100, a determination module 200 and an estimation module 300;

[0087] The acquisition module 100 is used to acquire the current operating state of the engine, wherein the operating state includes shutdown, warm-up and hot state;

[0088] The determination module 200 is used to determine a method for estimating the oil temperature based on the operating state, wherein the method for estimating the oil temperature includes a target factor, and the target factor is determined according to the operating state;

[0089] The estimation module 300 is used to estimate the engine oil temperature using the method.

[0090] In a possible implementation, the determining module 200 is specifically configured to:

[0091] When the operating state is a shutdown state, determining the target factor to be the ambient temperature and the engine water temperature;

[0092] Acquiring the ambient temperature and the engine water temperature;

[0093] determining a decay rate of engine oil temperature based on the ambient temperature and the engine water temperature;

[0094] The method for determining the estimated oil temperature is calculated based on the ambient temperature, the engine water temperature and the decay rate.

[0095] In a possible implementation, the determining module 200 is specifically configured to:

[0096] When the operating state is a warm-up state, the target factors are determined to be the engine speed, the number of engine revolutions and the oil temperature at the start time, and the oil temperature at the start time is related to the engine water temperature, the decay rate and the ambient temperature;

[0097] Calibrate the delay number of revolutions, which is the number of engine revolutions at the moment when the oil pan temperature rises when the temperature is lower than a preset temperature;

[0098] The method for determining the estimated oil temperature is to calculate it using the engine speed, the number of engine running circles, the oil temperature at the start time and the number of delay circles.

[0099] In a possible implementation, the determining module 200 is specifically configured to:

[0100] When the operating state is a hot engine state, determining the target factors as vehicle speed, engine speed, intake pressure, engine water temperature and intake temperature;

[0101] Calibrate the coefficient of vehicle speed, the coefficient of engine water temperature and the coefficient of intake air temperature;

[0102] The method for determining the estimated oil temperature is to calculate it using the engine speed, the number of engine running circles, the oil temperature at the start time, the number of delay circles, the coefficient of the vehicle speed, the coefficient of the engine water temperature and the coefficient of the intake temperature.

[0103] In a possible implementation, the determining module 200 is specifically configured to:

[0104] Under different ambient temperatures, heating the engine oil until the engine oil reaches a target temperature value;

[0105] When the engine oil reaches a target engine oil temperature value, cooling the engine oil;

[0106] During the cooling operation, the decay rate of the engine oil is calibrated to obtain a decay rate variation table, wherein the decay rate variation table includes a corresponding relationship between the ambient temperature, the engine water temperature and the decay rate;

[0107] The decay rate of the engine oil temperature under the current ambient temperature and engine water temperature is determined based on the decay rate change table.

[0108] In a possible implementation, the determining module 200 is specifically configured to:

[0109] Heating the engine oil, which circulates in the main oil gallery and the oil pan;

[0110] determining whether the oil pan generates heat exchange with the engine oil;

[0111] If yes, determining the time when the oil pan and the engine oil generate heat exchange to achieve temperature rise;

[0112] Obtaining the number of engine running revolutions at the moment when the temperature starts to rise;

[0113] The engine running number of revolutions is used as the delay number of revolutions to complete the calibration of the delay number of revolutions.

[0114] In a possible implementation, the estimation module 300 is specifically used for:

[0115] Method for obtaining estimated engine oil temperature;

[0116] Obtaining target parameter values ​​included in the method;

[0117] The engine oil temperature is estimated based on the target parameter value.

[0118] In this embodiment, a device for estimating the oil temperature is proposed, and the device includes: an acquisition module, a determination module and an estimation module. The acquisition module is used to obtain the current operating state of the engine, and the operating state includes shutdown, warm-up and hot state; the determination module is used to determine a method for estimating the oil temperature based on the operating state, and the method for estimating the oil temperature includes a target factor, and the target factor is determined according to the operating state; the estimation module is used to estimate the oil temperature using the method. In this way, by determining the influencing factors under the corresponding operating state according to different operating states of the engine, the oil temperature can be estimated in a targeted manner, and the influencing factors under different operating states can be taken into consideration, so that all factors involved in obtaining the estimated temperature of the oil can be fully considered, and the result of the estimated temperature obtained in the end is more accurate.

[0119] The present application also proposes a method for estimating the oil temperature in an application scenario. Specifically:

[0120] According to the oil temperature variation characteristics, the calculation of the estimated value can be divided into three states: engine shutdown, engine warm-up and engine hot engine.

[0121] When the engine is stopped, the current oil temperature decay rate is inferred based on the current ambient temperature and engine water temperature, and the current oil temperature is calculated. The decay rate can be regarded as a calibration constant that changes according to the engine water temperature and ambient temperature. In this state, the oil temperature should continue to decay.

[0122] During the engine warm-up process, considering that the combustion in the engine cylinder is the largest source of heating for the oil, the engine speed, engine running number of revolutions and oil temperature at the start time are the main considerations in this state, and the current state of the oil temperature is calculated in combination with the delay revolutions at the start time. The start delay revolutions are the heating delay revolutions determined based on the engine water temperature and ambient temperature at the start time, and the delay revolutions indicate the time required for the oil to warm up.

[0123] When the engine reaches the hot state, the oil temperature is in a state of thermal equilibrium, in which the temperature will not rise or fall significantly. The oil temperature calculation will include the following factors: vehicle speed, engine speed, intake pressure, engine water temperature and intake air temperature. Among them, the vehicle speed coefficient, water temperature coefficient and intake air temperature coefficient are calibration constants.

[0124] At the same time, the method for estimating the oil temperature in the above-mentioned application scenario was experimentally verified, specifically:

[0125] The above oil temperature estimation method was verified in steady state and transient state on the test bench and real vehicle, including:

[0126] Steady-state heating condition with stable engine speed, the actual vehicle engine speed verification range is 1000RPM to 5500RPM, and the ambient temperature verification range is -30 degrees Celsius to 25 degrees Celsius. The maximum error between the oil temperature model estimate and the actual temperature is 5 degrees Celsius.

[0127] For hot engine working condition verification, the engine water temperature verification range is 77 degrees Celsius to 101 degrees Celsius, the intake pressure verification range is 40kPa to 101kPa, the intake temperature verification range is -10 degrees Celsius to 28 degrees Celsius, and the ambient temperature verification range is -15 degrees to 32 degrees. The maximum error between the oil temperature model estimate and the actual temperature is 5 degrees Celsius.

[0128] In the shutdown decay condition, the oil temperature decays from 90 degrees Celsius to the ambient temperature at an ambient temperature of -20 degrees Celsius to 15 degrees Celsius. The maximum error between the oil temperature model estimate and the actual temperature is 3 degrees Celsius.

[0129] Comprehensive transient conditions, normal road tests were conducted at ambient temperatures between -30 degrees Celsius and 15 degrees Celsius, including engine start, stop, warm-up and hot engine state switching. The maximum error between the oil temperature model estimate and the actual temperature is 13 degrees Celsius.

[0130] The above experimental results show that the oil temperature estimation model can accurately calculate the engine oil temperature and can replace the actual sensor, effectively reducing the production cost of the whole vehicle.

[0131] The flow chart and block diagram in the accompanying drawings illustrate the possible implementation architecture, function and operation of the device and method according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, a program segment, or a part of a code, and the module, the program segment, or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some implementations as replacements, the functions marked in the box can also occur in a sequence different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0132] The embodiments of the present application also provide corresponding devices and computer-readable storage media for implementing the solutions provided by the embodiments of the present application.

[0133] The device includes a memory and a processor, the memory is used to store instructions or codes, and the processor is used to execute the instructions or codes so that the device executes a method for estimating oil temperature as described in any embodiment of the present application.

[0134] In practical applications, the computer-readable storage medium can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present embodiment, the computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it.

[0135] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0136] The program code embodied on the computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0137] Computer program code for performing the operations of the present invention may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0138] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0139] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for estimating engine oil temperature, characterized in that: The method comprises: Obtaining the current operating state of the engine, wherein the operating state includes shutdown, warm-up and hot state; a method for determining an estimated engine oil temperature based on the operating state, the method for estimating the engine oil temperature comprising a target factor, the target factor being determined based on the operating state; The method is used to estimate the engine oil temperature.

2. The method according to claim 1, characterized in that The method for determining an estimated engine oil temperature based on the operating state comprises: When the operating state is a shutdown state, determining the target factor to be the ambient temperature and the engine water temperature; Acquiring the ambient temperature and the engine water temperature; Obtaining a decay rate of engine oil temperature based on the ambient temperature and the engine water temperature; The method for determining the estimated oil temperature is calculated based on the ambient temperature, the engine water temperature and the decay rate.

3. The method according to claim 1, characterized in that The method for determining an estimated engine oil temperature based on the operating state comprises: When the operating state is a warm-up state, the target factors are determined to be the engine speed, the number of engine revolutions and the oil temperature at the start time, and the oil temperature at the start time is related to the engine water temperature, the decay rate and the ambient temperature; Calibrate the delay number of revolutions, which is the number of engine revolutions at the moment when the oil pan temperature rises when the temperature is lower than a preset temperature; The method for determining the estimated oil temperature is to calculate it using the engine speed, the number of engine running circles, the oil temperature at the start time and the number of delay circles.

4. The method according to claim 1, characterized in that The method for determining an estimated engine oil temperature based on the operating state comprises: When the operating state is a hot engine state, determining the target factors as vehicle speed, engine speed, intake pressure, engine water temperature and intake temperature; Calibrate the coefficient of vehicle speed, the coefficient of engine water temperature and the coefficient of intake air temperature; The method for determining the estimated oil temperature is to calculate it using the engine speed, the number of engine running circles, the oil temperature at the start time, the number of delay circles, the coefficient of the vehicle speed, the coefficient of the engine water temperature and the coefficient of the intake temperature.

5. The method according to claim 2, characterized in that: The determining the decay rate of the oil temperature based on the ambient temperature and the engine water temperature comprises: Under different ambient temperatures, heating the engine oil until the engine oil reaches a target temperature value; When the engine oil reaches a target engine oil temperature value, cooling the engine oil; During the cooling operation, the decay rate of the engine oil is calibrated to obtain a decay rate variation table, wherein the decay rate variation table includes a corresponding relationship between the ambient temperature, the engine water temperature and the decay rate; The decay rate of the engine oil temperature under the current ambient temperature and engine water temperature is determined based on the decay rate change table.

6. The method according to claim 3, characterized in that: The step of calibrating the number of delay turns includes: Heating the engine oil, the engine oil flowing in the main oil gallery and the oil pan; determining whether the oil pan contacts the engine oil and generates heat exchange based on the flow of the engine oil; If yes, determining the time when the oil pan and the engine oil generate heat exchange to achieve temperature rise; Obtaining the number of engine running revolutions corresponding to the moment when the temperature starts to rise; The engine running number of revolutions is used as the delay number of revolutions to complete the calibration of the delay number of revolutions.

7. The method according to claim 1, characterized in that The method for estimating the engine oil temperature includes: Method for obtaining estimated engine oil temperature; Obtaining target parameter values ​​included in the method; The engine oil temperature is estimated based on the target parameter value.

8. A device for estimating engine oil temperature, characterized in that: The device comprises: an acquisition module, a determination module and an estimation module; The acquisition module is used to acquire the current operating state of the engine, wherein the operating state includes shutdown, warm-up and hot state; The determination module is used to determine a method for estimating the oil temperature based on the operating state, the method for estimating the oil temperature includes a target factor, and the target factor is determined according to the operating state; The estimation module is used to estimate the engine oil temperature using the method.

9. An electronic device, characterized in that: The device includes: a processor, a memory, and a system bus; The processor and the memory are connected via the system bus; The memory is used to store one or more programs, wherein the one or more programs include instructions, and when the instructions are executed by the processor, the processor executes the method for estimating the engine oil temperature according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores an implementation program for the method for estimating the engine oil temperature. When the implementation program for the method for estimating the engine oil temperature is executed by a processor, the steps of the method as claimed in any one of claims 1 to 7 are implemented.

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