Engine water temperature estimation method, control method, device, vehicle and medium

Abstract

The invention provides an engine water temperature estimation method, a control method, a device, a vehicle and a medium, and relates to the technical field of engine cooling. The engine water temperature estimation method comprises the steps that a main water temperature sensor failure signal of an engine is received; the initial water temperature of the engine is obtained according to the state of the engine; the initial estimated water temperature of the engine is obtained according to the initial water temperature and the standing water temperature variation of the engine; and the real-time estimated water temperature of the engine is obtained according to the initial estimated water temperature and the operating water temperature variation of the engine. The water temperature measured by the water temperature sensor is replaced by the real-time estimated water temperature, so that the engine can be controlled through the real-time estimated water temperature, the engine can be ensured to run stably, the vehicle can be controlled to run normally, and the driving requirement of a user is met; and the situation that a user needs to convey the vehicle to a maintenance area in a rescue mode due to the failure of the water temperature sensor is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of engine cooling, and in particular to an engine water temperature estimation method, a control method, a device, a vehicle and a medium. Background Art

[0002] The engine water temperature signal can directly reflect the working status of the engine cooling system. Under normal circumstances, the temperature of the engine coolant should be maintained within a certain range to ensure that the engine can run efficiently and stably. The engine water temperature signal can not only reflect the working status of the engine and prevent engine overheating damage, but also assist in fault diagnosis and elimination and optimize engine performance.

[0003] For traditional pure fuel vehicles, or hybrid vehicles, including extended-range electric vehicles, if the engine water temperature sensor fails or the water temperature signal sent by the EMS (Engine Management System) through the CAN bus received by the VCU (Vehicle Control Unit) is invalid, in order to prevent the engine from overheating and damage, the engine water temperature will be assumed to exceed the operating range, thereby controlling the engine to shut down.

[0004] After the shutdown, traditional fuel vehicles will not be able to drive, and hybrid vehicles, such as extended-range electric vehicles, will run on pure electricity. However, since the pure electric range is very short, driving a short distance will cause the vehicle to be abandoned, and even require a tow truck to tow the vehicle for repairs, causing user anxiety and wasting user time. Summary of the invention

[0005] In view of the above problems existing in the prior art, the present invention provides an engine water temperature estimation method, control method, device, vehicle and medium to improve the situation in which the engine of the existing vehicle is controlled to shut down after the engine water temperature sensor fails, causing the vehicle to break down.

[0006] To achieve the above-mentioned and other related purposes, the present invention provides, in a first aspect, an engine water temperature estimation method, comprising:

[0007] Receive failure signal of main water temperature sensor of engine;

[0008] Acquiring an initial water temperature of the engine according to a state of the engine;

[0009] Obtaining an initial estimated water temperature of the engine according to the initial water temperature and a change in the static water temperature of the engine;

[0010] The real-time estimated water temperature of the engine is obtained according to the initial estimated water temperature and the change in the operating water temperature of the engine.

[0011] In an exemplary embodiment of the present invention, obtaining the initial water temperature of the engine according to the state of the engine includes:

[0012] Acquiring the state of the engine, wherein the state of the engine includes the stationary time of the engine;

[0013] If the static time is zero, the initial water temperature is the water temperature when the main water temperature sensor fails;

[0014] If the resting time is greater than zero and not greater than the first time threshold, the initial water temperature is the water temperature before the engine is at rest;

[0015] If the static time is greater than the first time threshold, the initial temperature is the external circulation coolant temperature.

[0016] In an exemplary embodiment of the present invention, the method further includes: obtaining vehicle model information, wherein the vehicle model information includes whether the vehicle is equipped with a two-way water temperature sensor;

[0017] If the vehicle includes two-way water temperature sensors, the external circulation coolant temperature is the temperature of the two-way water temperature sensors;

[0018] If the vehicle is not equipped with a two-way water temperature sensor, the external circulation coolant temperature is the ambient temperature.

[0019] In an exemplary embodiment of the present invention, obtaining the initial estimated water temperature of the engine according to the initial water temperature and the change in the static water temperature of the engine includes:

[0020] Obtaining the static water temperature change according to the state of the engine combined with the temperature drop rate, wherein the state of the engine includes the static time of the engine;

[0021] If the static time is equal to zero or the static time is greater than the first time threshold, the static water temperature change is zero, and the initial estimated water temperature is the initial water temperature;

[0022] If the static time is greater than zero and not greater than the first time threshold, the static water temperature change is the product of the temperature drop rate and the static time, and the initial estimated water temperature is the difference between the initial water temperature and the static water temperature change.

[0023] In an exemplary embodiment of the present invention, obtaining the engine running water temperature variation includes:

[0024] Get the engine's running time, power and vehicle speed;

[0025] Acquire a basic estimated temperature increase rate of the engine according to the power and the vehicle speed;

[0026] The operating water temperature change is obtained according to the engine operating time and the basic estimated temperature increase rate.

[0027] In an exemplary embodiment of the present invention, the real-time estimated water temperature of the engine is obtained according to the initial estimated water temperature and the change in the operating water temperature of the engine, including: the real-time estimated water temperature is the sum of the initial estimated water temperature and the change in the operating water temperature.

[0028] In an exemplary embodiment of the present invention, before the step of obtaining the real-time estimated water temperature of the engine according to the initial estimated water temperature and the change in the running water temperature of the engine, the method includes:

[0029] Obtain vehicle model information, including whether the vehicle is equipped with a two-way water temperature sensor;

[0030] If the vehicle includes the two-way water temperature sensor, the circulation state of the engine cooling liquid is obtained according to the temperature of the two-way water temperature sensor and the ambient temperature, and the circulation state includes a large circulation and a small circulation;

[0031] If the circulation state is the small circulation, the real-time estimated water temperature is the sum of the initial estimated water temperature and the running water temperature change;

[0032] If the circulation state is the large circulation, the real-time estimated water temperature is the temperature of the two-way water temperature sensor.

[0033] In an exemplary embodiment of the present invention, the circulation state of the engine cooling liquid is obtained according to the temperature of the two-way water temperature sensor and the ambient temperature, and the circulation state includes a large circulation and a small circulation, including:

[0034] Obtaining the difference between the temperature of the two-way water temperature sensor and the ambient temperature;

[0035] If the difference is greater than a first temperature threshold, the cycle state is a large cycle;

[0036] If the difference is not greater than the first temperature threshold, the cycle state is a small cycle.

[0037] In an exemplary embodiment of the present invention, if the vehicle is not equipped with the two-way water temperature sensor, the real-time estimated water temperature is the sum of the initial estimated water temperature and the running water temperature change.

[0038] In an exemplary embodiment of the present invention, if the vehicle model is not equipped with the two-way water temperature sensor, after obtaining the real-time estimated water temperature, the real-time estimated water temperature is further verified, and the verification includes:

[0039] Get the large circulation water temperature when the engine large circulation is fully opened;

[0040] Comparing the real-time estimated water temperature with the large circulation water temperature;

[0041] If the real-time estimated water temperature is not greater than the large circulation water temperature, the real-time estimated water temperature is used as the actual real-time water temperature;

[0042] If the real-time estimated water temperature is greater than the large circulation water temperature, then calculating the temperature difference between the real-time estimated water temperature and the large circulation water temperature;

[0043] If the temperature difference is not greater than a second temperature threshold, turning on the radiator fan;

[0044] If the temperature difference is greater than a second temperature threshold, the engine circulation water circuit and the air conditioning heater water circuit are connected in series, and the real-time estimated water temperature is corrected with the water temperature of the air conditioning heater water circuit, and is output as the actual real-time water temperature.

[0045] In an exemplary embodiment of the present invention, if the temperature difference is greater than the second temperature threshold, the engine circulation water circuit and the air conditioning warm air water circuit are connected in series, and the water temperature of the air conditioning warm air water circuit is used as the real-time estimated water temperature and output as the actual real-time water temperature, and then further includes:

[0046] If the actual real-time water temperature is not higher than the large circulation water temperature, the engine circulation water circuit and the air conditioning heating circuit are disconnected, and the real-time estimated water temperature and the large circulation water temperature are continuously compared.

[0047] In an exemplary embodiment of the present invention, after the step of receiving the failure signal of the main water temperature sensor of the engine, the method includes:

[0048] Obtain vehicle model information, including whether the vehicle is equipped with a two-way water temperature sensor;

[0049] If the vehicle is equipped with two water temperature sensors, obtain the temperatures of the two water temperature sensors;

[0050] Determining the circulation state of the engine according to the temperature of the two-way water temperature sensor;

[0051] If the circulation state is large circulation, the temperature of the two-way water temperature sensor is used as the real-time estimated water temperature;

[0052] If the cycle state is a small cycle, the process enters a step of obtaining the initial water temperature of the engine according to the state of the engine until the real-time estimated water temperature of the engine is obtained.

[0053] A second aspect of the present invention is to provide an engine control method for continuing to control the engine after the engine main water temperature sensor fails, comprising obtaining an estimated engine water temperature through any of the engine water temperature estimation methods described above, replacing the engine main water temperature sensor with the estimated engine water temperature to control the engine operation, and reducing the power output of the entire vehicle to half.

[0054] The third aspect of the present invention is to provide an engine water temperature estimation device, the device comprising a receiving module, an initial water temperature acquisition module, an initial estimated water temperature acquisition module and a real-time estimated water temperature acquisition module. The receiving module is used to receive a failure signal of the main water temperature sensor of the engine; the initial water temperature acquisition module is used to acquire the initial water temperature of the engine according to the state of the engine; the initial estimated water temperature acquisition module is used to acquire the initial estimated water temperature of the engine according to the initial water temperature and the change in the static water temperature of the engine; the real-time estimated water temperature acquisition module is used to acquire the real-time estimated water temperature of the engine according to the initial estimated water temperature and the change in the running water temperature of the engine.

[0055] The fourth aspect of the present invention is to provide a vehicle, comprising one or more processors; a storage device for storing one or more programs, when the one or more programs are executed by the one or more processors, the vehicle implements any of the above-mentioned engine water temperature estimation methods.

[0056] A fifth aspect of the present invention is a computer-readable storage medium having computer-readable instructions stored thereon, which, when executed by a processor of a computer, causes the computer to execute any of the above-described engine water temperature estimation methods.

[0057] In combination with the prior art, the beneficial effects of the present invention are:

[0058] When the existing vehicle engine water temperature sensor signal fails, the vehicle will assume that the engine water temperature exceeds the normal operating range, and then control the engine to shut down, causing the vehicle to be unable to drive, affecting user use. The method of the present application, after receiving the failure signal of the engine's main water temperature sensor, first obtains the initial water temperature of the engine, then obtains the initial estimated water temperature based on the initial water temperature and the static water temperature change, and then obtains the real-time estimated water temperature of the engine based on the initial estimated water temperature and the engine's running water temperature change. The real-time estimated water temperature replaces the water temperature measured by the water temperature sensor, and then the engine can be controlled by the real-time estimated water temperature to ensure that the engine can operate stably, control the normal driving of the vehicle, meet the user's driving needs, and reduce the situation where the user needs to transport the vehicle to the maintenance area through rescue due to the failure of the water temperature sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in 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 in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0060] Figure 1 It is a schematic diagram of an embodiment of an engine water temperature estimation method of the present invention;

[0061] Figure 2 It is a schematic diagram of obtaining the initial water temperature in the first embodiment of the engine water temperature estimation method of the present invention;

[0062] Figure 3 It is a schematic diagram of obtaining the initial estimated water temperature in the first embodiment of the engine water temperature estimation method of the present invention;

[0063] Figure 4 It is a schematic diagram of obtaining the running water temperature variation in the first embodiment of the engine water temperature estimation method of the present invention;

[0064] Figure 5 It is a schematic diagram of obtaining the real-time estimated water temperature in the first embodiment of the engine water temperature estimation method of the present invention;

[0065] Figure 6 It is a schematic diagram of an embodiment of an engine water temperature estimation device of the present invention;

[0066] Figure 7 FIG. 1 is a schematic diagram of electronic components in a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0067] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the features in the following embodiments and embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific embodiments, rather than to limit the scope of protection of the present invention. The test methods for which specific conditions are not indicated in the following examples are usually carried out under conventional conditions or according to the conditions recommended by the manufacturers.

[0068] When numerical ranges are given in the embodiments, it should be understood that unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are familiar to those skilled in the art and the description of the present invention, and any method, device and material of the prior art similar or equivalent to the method, device and material in the embodiments of the present invention can also be used to implement the present invention.

[0069] The engine water temperature sensor is an important part of the automobile engine management system. When the engine is in a low temperature state, the water temperature sensor will send a signal to the electronic control unit to request an increase in the amount of fuel injection to ensure that the engine can start smoothly and heat up quickly. As the engine temperature rises, the water temperature sensor will send a signal to gradually reduce the amount of fuel injection to maintain the best operating efficiency of the engine. When the engine temperature is low, the electronic control unit will control the action of the idle control valve according to the signal of the water temperature sensor to increase the idle speed of the engine and ensure that the engine can operate normally in a low temperature environment. When the water temperature sensor detects that the engine coolant temperature is too high, it will send a signal to the electronic control unit to trigger the operation of the cooling system, such as turning on the fan or adjusting the water pump flow to prevent the engine from overheating and causing damage. The water temperature sensor can monitor the temperature changes of the coolant in real time, and convert this information into electrical signals and transmit it to the electronic control unit, so as to achieve accurate management of fuel injection, ignition timing, idle speed control and other aspects. At the same time, it also has thermal protection and fault monitoring functions to ensure that the engine operates in a safe and efficient state.

[0070] In traditional fuel vehicles or hybrid vehicles, if the engine water temperature sensor fails, the engine water temperature will be assumed to exceed the operating range, thereby controlling the engine to shut down, which may easily cause the vehicle to break down, seriously affecting user use.

[0071] In view of this, the first aspect of the present invention provides an engine water temperature estimation method, so that after the main water temperature sensor of the engine fails, the engine water temperature can be estimated in real time, thereby replacing the main water temperature sensor to measure the water temperature, maintaining the continuous and stable operation of the engine, and ensuring that users can independently send the vehicle for inspection and maintenance, etc.

[0072] See also Figure 1 , a method for estimating engine water temperature has the following specific steps:

[0073] Step S110: receiving a failure signal of a main water temperature sensor of the engine.

[0074] After receiving the failure signal of the main water temperature sensor of the engine, the controller enters the engine water temperature estimation method process, and then estimates the water temperature of the engine, thereby achieving stable control of the engine.

[0075] Step S120: acquiring an initial water temperature of the engine according to the state of the engine.

[0076] The state of the engine includes the engine's rest time, wherein if the engine is always in the running state, the engine's rest time is zero. If the engine is not running, the engine's rest time is calculated based on the actual value.

[0077] See also Figure 2 , Figure 2 An exemplary process of obtaining the initial water temperature of the engine according to the state of the engine is shown, and the specific steps are as follows:

[0078] Step S210: Acquire the state of the engine, where the state of the engine includes the stationary time of the engine.

[0079] When the main water temperature sensor fails, the engine is in a running state, and the engine's rest time is zero. When the engine is in a rest state, the duration of the engine's rest phase is obtained.

[0080] Step S220: Determine whether the static time is zero.

[0081] If the static time is zero, the process proceeds to step S230, where the initial water temperature is the water temperature when the main water temperature sensor fails.

[0082] If the rest time is zero, it indicates that when the main water temperature sensor fails, the engine is in a running state, and the initial water temperature at this time is the water temperature when the main water temperature sensor fails.

[0083] If the static time is not zero, the process proceeds to step S240 to determine whether the static time is greater than a first time threshold.

[0084] In one embodiment, the first time threshold is obtained according to experimental calibration, such as the time required for the engine water temperature to drop to the ambient temperature. The time required for the engine water temperature to drop to the ambient temperature is different for different ambient temperatures. The first time threshold is preferably a value that takes a longer time to drop to the ambient temperature, such as the engine water temperature drops from the water temperature when the engine large cycle is turned on to the value when the ambient temperature is minus 20 degrees Celsius. In the experimental calibration, when the ambient temperature is low, the heat transfer of the engine coolant is faster and the temperature drops faster; when the ambient temperature is high, the heat transfer rate of the engine coolant is slower and the temperature drops slower. The first time threshold is preferably a value that takes a longer time to drop to the ambient temperature.

[0085] In another embodiment, the first duration threshold can be selected according to living habits. For example, if the user group uses vehicles more often for commuting, and usually works for eight hours, and according to experimental calculations, most vehicles can reach the ambient temperature after eight hours, then the first duration threshold can be selected as eight hours. The first duration threshold can also be selected as any value between 6 and 12 hours, such as 6 hours, 8 hours, 10 hours, 12 hours, etc.

[0086] If the standing time is longer than the first time threshold, the process proceeds to step S250, where the initial water temperature is the external circulation coolant temperature.

[0087] The engine's external circulation coolant is the same as the coolant used in the engine's internal circulation. Therefore, the heat transfer efficiency of the external circulation coolant is basically the same as the heat transfer efficiency of the engine's internal coolant. Using the engine's external circulation coolant temperature as the engine's initial water temperature can improve the accuracy of the engine's initial water temperature, thereby improving the accuracy of the engine's water temperature estimation.

[0088] The circulation state of the engine cooling liquid includes large circulation and small circulation. The large circulation and small circulation of the engine are two important working modes of the engine cooling system. The difference lies in whether the cooling water flows through the radiator. The large circulation refers to the process in which the coolant flows out of the engine body, passes through the radiator for heat dissipation and cooling, and then enters the engine body to cool the engine; the small circulation refers to the process in which most of the coolant flows out of the engine body without passing through the radiator for heat dissipation and cooling, but directly enters the engine body to cool the engine.

[0089] The external circulation coolant temperature refers to the temperature of the coolant outside the engine body before flowing through the radiator. When the engine is in a large circulation, the external circulation coolant temperature is the same or basically the same as the coolant temperature inside the engine body; when the engine is in a small circulation, the external circulation coolant temperature and the coolant temperature inside the engine body are usually different; after the engine has been stationary for a first time threshold, the external circulation coolant temperature and the coolant temperature inside the engine body are generally considered to be the same or basically the same.

[0090] In one embodiment, obtaining the temperature of the external circulation coolant includes the following specific steps:

[0091] The vehicle model information is obtained, including whether the vehicle is equipped with a two-way water temperature sensor.

[0092] The two-way water temperature sensor is arranged at the radiator of the engine's large circulation or in front of the radiator, and is used to monitor the water temperature of the engine's large circulation. The two-way water temperature sensor can be a winding resistor water temperature sensor, a thermistor water temperature sensor, or other water temperature sensors. Preferably, the two-way water temperature sensor is a thermistor water temperature sensor.

[0093] The step of obtaining the vehicle model information can be performed before step S250, when the initial water temperature is the external circulation coolant temperature, for example, after step S110, when the failure signal of the main water temperature sensor of the engine is received, or before step S110; it can also be performed after step S250 to judge the vehicle model information according to actual needs.

[0094] The external circulation coolant temperature is obtained according to whether the vehicle is equipped with a two-way water temperature sensor. If the vehicle includes a two-way water temperature sensor, the external circulation coolant temperature is the temperature of the two-way water temperature sensor; if the vehicle is not equipped with a two-way water temperature sensor, the external circulation coolant temperature is the ambient temperature.

[0095] If the standing time is not greater than the first threshold, the process proceeds to step S260, where the initial water temperature is the water temperature before the engine is standing still.

[0096] If the engine main water temperature sensor is damaged when the engine is at rest, the water temperature value measured by the main water temperature sensor before the engine is at rest is used as the initial water temperature. If the engine is damaged before it is at rest, the real-time estimated water temperature before the engine is at rest is used as the initial water temperature.

[0097] Step S130: obtaining an initial estimated water temperature of the engine according to the initial water temperature and the change in the static water temperature of the engine.

[0098] See also Figure 3 , Figure 3 This is a schematic diagram of obtaining the initial estimated water temperature in an embodiment of the engine water temperature estimation method of the present invention. The specific steps are as follows:

[0099] Step S310: acquiring the static water temperature change according to the state of the engine and the temperature drop rate, wherein the state of the engine includes the static time of the engine.

[0100] Step S320: determine whether the static time is zero.

[0101] If the standing time is zero, the change in water temperature is zero.

[0102] If the stationary time is zero, it indicates that the engine is in continuous operation, and there is no change in the stationary water temperature. The stationary water temperature is zero, and the initial water temperature is the initial estimated water temperature.

[0103] If the static time is not zero, the process proceeds to step S330 to determine whether the static time is greater than a first time threshold.

[0104] If the static time is greater than the first time threshold, the initial temperature is the current external circulation coolant temperature, so it is determined that the static water temperature change is zero. The initial estimated water temperature is the difference between the initial water temperature and the static water temperature change. Since the static water temperature change is zero, the initial estimated water temperature is the initial water temperature.

[0105] If the standing time is not greater than the first time threshold, the process proceeds to step S340, where the standing water temperature change is the product of the temperature drop rate and the standing time.

[0106] The temperature drop rate is obtained by experimental calibration. In one embodiment, the temperature drop rate is a constant, and the unit is degrees Celsius per second or degrees Celsius per minute, etc. The temperature drop rate is lower than the average rate at which the engine large cycle temperature drops to the ambient temperature, so that in most cases the initial estimated water temperature is higher than the actual water temperature, avoiding the situation where the actual water temperature is too high but the initial estimated water temperature is too low, causing the engine overheating failure.

[0107] In one embodiment, the temperature drop rate is calibrated for different vehicle models. During the calibration, only the engine water temperature and the ambient temperature at the beginning of the experiment are considered, and then the average value of the water temperature drop per unit time is obtained, and the temperature drop rate is determined according to the average value. For example, the engine temperature drop rates of different vehicle models are 6°C / h, 8°C / h, 8.5°C / h, 10°C / h, etc., which are obtained through experimental calibration according to the vehicle model and the selected coolant. By determining the temperature drop rate as a constant, the data model parameters are relatively small and the practical applicability is strong, avoiding the introduction of too many parameters to make the data model complicated, resulting in the situation that it cannot be actually implemented. And according to experimental calculations, the introduction of too many parameters will not have much impact on the temperature drop rate. Therefore, while ensuring that the temperature drop rate is basically accurate, fewer parameters are used to improve the practicality of the data model. The initial estimated water temperature has a certain deviation from the actual water temperature. Usually, the initial estimated water temperature is higher than the actual water temperature, thereby avoiding the situation where the estimated water temperature is too low and causes engine overheating failure. In this embodiment, when the real-time estimated water temperature is too high, it can be verified, thereby improving the accuracy of the real-time estimated water temperature and avoiding the situation where the real-time estimated water temperature is too high and causes false alarm of engine failure.

[0108] After obtaining the static water temperature change, the process proceeds to step S350 to obtain the initial estimated water temperature through the difference between the initial water temperature and the static water temperature change.

[0109] The initial estimated water temperature is the difference between the initial water temperature and the change in the static water temperature. The initial estimated water temperature is obtained by calculation.

[0110] Step S140: obtaining the real-time estimated water temperature of the engine according to the initial estimated water temperature and the change in the operating water temperature of the engine.

[0111] The real-time estimated water temperature of the engine can be obtained based on the sum of the initial estimated water temperature and the change in the operating water temperature during engine operation.

[0112] See also Figure 5 , Figure 5This is a schematic diagram of obtaining the real-time estimated water temperature in an embodiment of the engine water temperature estimation method of the present invention. The specific steps are as follows:

[0113] Step S510: Obtain vehicle model information, which includes whether a two-way water temperature sensor is installed.

[0114] Step S520: Determine whether two-way water temperature sensors are installed.

[0115] It should be noted that step S510 and step S520 can be performed after step S130, that is, after obtaining the initial estimated water temperature, to obtain vehicle model information, and then determine whether the vehicle is equipped with a two-way water temperature sensor; step S510 and step S520 can also be performed before step S130, for example, after step S110, that is, after receiving the failure signal of the main water temperature sensor of the engine, to obtain vehicle model information, and then determine whether the vehicle is equipped with a two-way water temperature sensor. Of course, as some optional solutions, step S510 and step S520 can also be arranged in order according to actual needs.

[0116] Step S510 and step S520 can be continuous steps, that is, step S520 is directly after step S510; step S510 and step S520 can also be discontinuous steps, that is, there are other steps between step S510 and step S520, for example, step S510 first obtains vehicle model information after step S11, that is, after receiving the failure signal of the main water temperature sensor of the engine, and then determines whether the vehicle is equipped with a two-way water temperature sensor when it is necessary to obtain the real-time estimated water temperature. Of course, as some optional solutions, step S510 and step S520 can be arranged in a suitable order according to actual needs.

[0117] If two-way water temperature sensors are not installed, the process proceeds to step S530, where the real-time estimated water temperature is the sum of the initial estimated water temperature and the operating water temperature change.

[0118] If two water temperature sensors are included, the process proceeds to step S540 to obtain the circulation status of the engine cooling liquid according to the temperatures of the two water temperature sensors and the ambient temperature.

[0119] The circulation state of the engine cooling liquid includes large circulation and small circulation. The large circulation and small circulation of the engine are two important working modes of the engine cooling system. The difference lies in whether the cooling water flows through the radiator. The large circulation refers to the process in which the coolant flows out of the engine body, passes through the radiator for heat dissipation, and then enters the engine body to cool the engine; the small circulation refers to the process in which most of the coolant flows out of the engine body without passing through the radiator for heat dissipation, but directly enters the engine body to cool the engine.

[0120] Step S550: Determine whether the loop state is a large loop.

[0121] By comparing the large cycle and the small cycle, we can know that the difference between the large cycle and the small cycle lies in whether the coolant flows through the radiator to dissipate heat, that is, whether the engine coolant passes through the two-way water temperature sensor. If the engine's circulation state is a large cycle, the temperature of the two-way water temperature sensor is higher. If the engine's circulation state is a small cycle, the temperature of the two-way water temperature sensor is similar to the ambient temperature. The specific judgment process is as follows:

[0122] Obtain the difference between the temperature of the two-way water temperature sensor and the ambient temperature.

[0123] If the difference is greater than the first temperature threshold, the cycle state is a large cycle.

[0124] The first temperature threshold is used to determine the approximate value of the two-way water temperature sensor and the ambient temperature, and then determine whether the engine coolant enters the two-way circulation, that is, whether it enters the large circulation. The first temperature threshold can be obtained based on experimental calibration or experience. In one embodiment, the first temperature threshold can be 3 to 15°C, and the first temperature threshold can be any value between 3 and 15°C, such as 3°C, 8°C, 10°C, 15°C, etc.

[0125] If the difference is not greater than the first temperature threshold, it is considered that the temperature of the second-way coolant is similar to the ambient temperature, the second-way coolant does not participate in the engine cooling cycle, and the circulation state is a small cycle.

[0126] If the circulation state is a large circulation, the process proceeds to step S560, and the real-time estimated water temperature is the temperature of the two-way water temperature sensor.

[0127] If the circulation state is a small circulation, the process proceeds to step S530, where the real-time estimated water temperature is the sum of the initial estimated water temperature and the operating water temperature change.

[0128] See also Figure 4 , Figure 4 This is a schematic diagram of obtaining the running water temperature variation in the first embodiment of the engine water temperature estimation method of the present invention. The specific method of obtaining the running water temperature variation of the engine is as follows:

[0129] Step S410: Obtain the engine running time, power and vehicle speed.

[0130] Step S420: Obtain a basic estimated temperature increase rate of the engine according to the power and the vehicle speed.

[0131] The corresponding relationship between power, vehicle speed and basic estimated temperature increase rate of the engine is obtained in advance through experimental calibration, so that the basic estimated temperature increase rate of the engine can be determined according to power and vehicle speed.

[0132] In one embodiment, the basic estimated temperature increase rate only considers the influence of engine power and vehicle speed. Through experiments and analysis, it can be known that the basic estimated temperature increase rate has a certain relationship with the ambient temperature, but the influence of ambient temperature on the basic estimated temperature increase rate is limited. The method of the present invention only considers the engine power and vehicle speed, and a relatively accurate value can be obtained through fewer parameters, so that the calculation of the basic estimated temperature increase rate is practical, and the situation that the introduction of more parameters cannot be implemented is avoided. In addition, the method of the present invention verifies the real-time estimated water temperature through a two-way water temperature sensor or a water temperature sensor of the air conditioning and heating system, so that the real-time estimated water temperature is verified when the real-time estimated water temperature is higher than the actual water temperature, thereby reducing the error of the real-time estimated water temperature.

[0133] In one embodiment, the unit of the basic estimated temperature increase rate is degrees Celsius per second, which improves the accuracy of the basic estimated temperature increase rate.

[0134] Step S430: Obtain the operating water temperature change according to the engine operating time and the basic estimated temperature increase rate.

[0135] The running water temperature change is obtained by multiplying the engine running time by the basic estimated temperature increase rate. For example, when the engine power is 5 kW and the vehicle speed is 10 km / h, the basic estimated temperature increase rate is B. 1 , the engine running time under this parameter is A 1 ; When the engine power is 6kw and the vehicle speed is 15km / h, the basic estimated temperature increase rate is B 2 , the engine running time under this parameter is A 2 ; Then the running water temperature change Y = A 1 B 1 +A 2 B 2 .

[0136] After obtaining the real-time estimated water temperature of the engine, the real-time estimated water temperature is verified as needed. If the vehicle is equipped with a two-way water temperature sensor, when the engine water temperature is high, the main valve of the engine thermostat opens and the engine enters a large cycle. Using the temperature of the two-way water temperature sensor as the real-time estimated water temperature can ensure the accuracy of the real-time estimated water temperature, and no verification is required.

[0137] If the vehicle is not equipped with a two-way water temperature sensor, when the engine's circulation state is a large circulation, the real-time estimated water temperature cannot be calibrated by a suitable water temperature sensor, and the real-time estimated water temperature will be too high, causing the engine to falsely report a fault. Therefore, when the vehicle is not equipped with a two-way water temperature sensor, the real-time estimated water temperature needs to be verified. The specific verification steps are as follows:

[0138] The large circulation water temperature of the engine when all large circulations are opened is obtained.

[0139] Comparing the real-time estimated water temperature with the large circulation water temperature;

[0140] If the real-time estimated water temperature is not greater than the large circulation water temperature, the real-time estimated water temperature is used as the actual real-time water temperature.

[0141] In the method of the present invention, the real-time estimated water temperature is usually higher than the actual water temperature to ensure that the engine will not malfunction due to excessive actual water temperature. If the real-time estimated water temperature is not greater than the large circulation water temperature, it means that the actual water temperature is within the normal operating range of the engine, and the engine can be controlled according to the real-time estimated water temperature.

[0142] If the real-time estimated water temperature is greater than the large circulation water temperature, then calculating the temperature difference between the real-time estimated water temperature and the large circulation water temperature;

[0143] If the temperature difference is not greater than a second temperature threshold, turning on the radiator fan;

[0144] The second temperature threshold is obtained according to experimental calibration, and the second temperature threshold can be any value between 1 and 6°C, such as 1°C, 3°C, 6°C, etc. By turning on the radiator fan, the radiator is cooled to ensure timely and effective heat dissipation of the engine.

[0145] In one embodiment, the radiator fan duty cycle is output according to the minimum operation duty cycle to reduce energy loss.

[0146] If the temperature difference is greater than a second temperature threshold, the engine circulation water circuit and the air conditioning heater water circuit are connected in series, and the real-time estimated water temperature is corrected with the water temperature of the air conditioning heater water circuit, and is output as the actual real-time water temperature.

[0147] When the temperature difference is greater than the second temperature threshold, it indicates that the real-time estimated water temperature is high. In order to avoid excessive engine temperature and false alarm of faults, the real-time estimated water temperature is calibrated by the water temperature of the air-conditioning warm air water circuit. The water temperature of the air-conditioning warm air water circuit is used as the real-time estimated water temperature, that is, the real-time estimated water temperature is assigned a value using the water temperature value of the air-conditioning warm air water circuit and then output.

[0148] In one embodiment, a three-way valve is provided between the engine circulating water circuit and the air-conditioning warm air water circuit. When the real-time estimated water temperature is higher than the sum of the large circulating water temperature and the second temperature threshold, the three-way valve connects the engine circulating water circuit and the air-conditioning warm air water circuit, thereby utilizing the inlet temperature in the thermal management air-conditioning pipeline to detect the actual temperature of the engine circulating water circuit, and then calibrates the real-time estimated water temperature by the temperature of the water PTC (Positive Temperature Coefficient) inlet in the air-conditioning warm air water circuit, replaces the value in the real-time estimated water temperature with the temperature of the air-conditioning warm air water circuit, and outputs it as the actual real-time water temperature.

[0149] In one embodiment, if the actual real-time water temperature is not higher than the large circulation water temperature, the engine circulation water circuit and the air conditioning heating circuit are disconnected, and the real-time estimated water temperature and the large circulation water temperature are continuously compared.

[0150] After the real-time estimated water temperature is calibrated, the real-time estimated water temperature is recalculated using the real-time estimated water temperature as the initial estimated water temperature to improve the accuracy of the real-time estimated water temperature.

[0151] In one embodiment, after receiving the failure signal of the main water temperature sensor of the engine, the following steps are included:

[0152] Obtain vehicle model information, including whether the vehicle is equipped with a two-way water temperature sensor;

[0153] If the vehicle is equipped with two water temperature sensors, the temperatures of the two water temperature sensors are obtained.

[0154] The circulation state of the engine is judged according to the temperature of the two-way water temperature sensor, and the specific judging steps include:

[0155] The difference between the temperature of the two-way water temperature sensor and the ambient temperature is obtained; if the difference is greater than a first temperature threshold, the circulation state is a large circulation. If the difference is not greater than the first temperature threshold, it is considered that the temperature of the two-way coolant is similar to the ambient temperature, the two-way coolant does not participate in the engine cooling cycle, and the circulation state is a small circulation.

[0156] If the circulation state is a large circulation, the temperature of the two-way water temperature sensor is used as the real-time estimated water temperature; if the circulation state is a small circulation, enter step S120.

[0157] The method of the present invention can estimate the real-time water temperature of the engine and then control the engine. At the same time, the real-time estimated water temperature can be verified and calibrated using a two-way water temperature sensor or a water temperature sensor of an air conditioning heater pipe, thereby improving the accuracy of the real-time estimated water temperature and allowing the vehicle to be controlled and driven normally.

[0158] A second aspect of the present invention is to provide an engine control method for continuing to control the engine after the engine main water temperature sensor fails, including obtaining an estimated engine water temperature through any of the engine water temperature estimation methods described above, replacing the engine main water temperature sensor with the estimated engine water temperature to control the engine operation, and reducing the power output of the entire vehicle to half to avoid a situation where the estimated engine water temperature deviates too much due to aggressive driving by the user.

[0159] When receiving the engine's main water temperature sensor failure signal, the vehicle sends a main water temperature sensor failure reminder to the user, such as through instrument display, broadcast, etc., to remind the user to check and repair in time.

[0160] See also Figure 6 , Figure 6 This is a schematic diagram of an embodiment of an engine water temperature estimation device of the present invention. The third aspect of the present invention is to provide an engine water temperature estimation device, the device comprising a receiving module, an initial water temperature acquisition module, an initial estimated water temperature acquisition module and a real-time estimated water temperature acquisition module. The receiving module is used to receive a failure signal of the main water temperature sensor of the engine; the initial water temperature acquisition module is used to obtain the initial water temperature of the engine according to the state of the engine and the vehicle type information; the initial estimated water temperature acquisition module is used to obtain the initial estimated water temperature of the engine according to the initial water temperature and the change in the static water temperature of the engine; the real-time estimated water temperature acquisition module is used to obtain the real-time estimated water temperature of the engine according to the vehicle type information, the initial estimated water temperature and the change in the running water temperature of the engine.

[0161] It should be noted that the engine water temperature estimation device provided in the above embodiment and the engine water temperature estimation method provided in the above embodiment belong to the same concept, wherein the specific manner in which each module and unit performs the operation has been described in detail in the method embodiment and will not be repeated here. In actual application, the engine water temperature estimation device provided in the above embodiment can allocate the above functions to different functional modules as needed, that is, divide the internal structure of the device into different functional modules to complete all or part of the functions described above, and this is not limited here.

[0162] The fourth aspect of the present invention is to provide a vehicle, comprising one or more processors; a storage device for storing one or more programs, when the one or more programs are executed by the one or more processors, the vehicle implements any of the above-mentioned engine water temperature estimation methods.

[0163] Figure 7 The structure diagram of the computer system of the vehicle suitable for implementing the embodiment of the present application is shown. It should be noted that: Figure 7The vehicle computer system 700 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0164] like Figure 7 As shown, the computer system 700 includes a central processing unit (CPU) 701, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 702 or the program loaded from the storage part 708 to the random access memory (RAM) 703, such as executing the method described in the above embodiment. In the RAM 703, various programs and data required for system operation are also stored. The CPU 701, ROM 702 and RAM 703 are connected to each other through a bus 704. An input / output (I / O) interface 705 is also connected to the bus 704.

[0165] The following components are connected to the I / O interface 705: an input section 706 including voice, keys, etc.; an output section 707 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker; a storage section 708 including a hard disk, etc.; and a communication section 709 including a network interface card such as a LAN (Local Area Network) card, a modem, etc. The communication section 709 performs communication processing via a network such as the Internet. A drive 710 is also connected to the I / O interface 705 as needed. A removable medium 711, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 710 as needed, so that a computer program read therefrom is installed into the storage section 708 as needed.

[0166] In particular, according to an embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a computer program for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication section 709, and / or installed from a removable medium 711. When the computer program is executed by a central processing unit (CPU) 701, various functions defined in the system of the present application are executed.

[0167] It should be noted that the computer-readable medium shown in the embodiment of the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media can include, but are not limited to: 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), a 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 application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, wherein a computer-readable computer program is carried. This propagated data signal can take a variety of forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the above. A computer-readable signal medium 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. A computer program contained on a computer-readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0168] A fifth aspect of the present invention is a computer-readable storage medium having computer-readable instructions stored thereon, which, when executed by a processor of a computer, causes the computer to execute any of the above-described engine water temperature estimation methods.

[0169] Another aspect of the present application also provides a computer program product or a computer program, which includes a computer instruction stored in a computer-readable storage medium. A processor of a computer device reads the computer instruction from the computer-readable storage medium, and the processor executes the computer instruction, so that the computer device executes the engine water temperature estimation method provided in each of the above embodiments.

[0170] The engine water temperature estimation method of the present invention estimates the water temperature of the engine after the main water temperature sensor of the engine fails, and then controls the engine by estimating the water temperature in real time, thereby achieving stable control of the engine, so that the user can still drive the vehicle after the main water temperature sensor of the engine fails. Therefore, the present invention effectively overcomes some practical problems in the prior art and has high utilization value and use significance.

[0171] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for estimating engine water temperature, characterized in that: include: Receive failure signal of main water temperature sensor of engine; Acquiring an initial water temperature of the engine according to a state of the engine; Obtaining an initial estimated water temperature of the engine according to the initial water temperature and a change in the static water temperature of the engine; The real-time estimated water temperature of the engine is obtained according to the initial estimated water temperature and the change in the operating water temperature of the engine.

2. The engine water temperature estimation method according to claim 1, characterized in that: Acquiring the initial water temperature of the engine according to the state of the engine, comprising: Acquiring the state of the engine, wherein the state of the engine includes the stationary time of the engine; If the static time is zero, the initial water temperature is the water temperature when the main water temperature sensor fails; If the resting time is greater than zero and not greater than the first time threshold, the initial water temperature is the water temperature before the engine is at rest; If the static time is greater than the first time threshold, the initial temperature is the external circulation coolant temperature.

3. The engine water temperature estimation method according to claim 2, characterized in that: Also includes: Obtain vehicle model information, including whether the vehicle is equipped with a two-way water temperature sensor; If the vehicle includes two-way water temperature sensors, the external circulation coolant temperature is the temperature of the two-way water temperature sensors; If the vehicle is not equipped with a two-way water temperature sensor, the external circulation coolant temperature is the ambient temperature.

4. The engine water temperature estimation method according to claim 1, characterized in that: Obtaining an initial estimated water temperature of the engine according to the initial water temperature and the change in the stationary water temperature of the engine includes: Obtaining the static water temperature change according to the state of the engine combined with the temperature drop rate, wherein the state of the engine includes the static time of the engine; If the static time is equal to zero or the static time is greater than the first time threshold, the static water temperature change is zero, and the initial estimated water temperature is the initial water temperature; If the static time is greater than zero and not greater than the first time threshold, the static water temperature change is the product of the temperature drop rate and the static time, and the initial estimated water temperature is the difference between the initial water temperature and the static water temperature change.

5. The engine water temperature estimation method according to claim 1, characterized in that: The acquisition of engine running water temperature change includes: Get the engine's running time, power and vehicle speed; Acquire a basic estimated temperature increase rate of the engine according to the power and the vehicle speed; The operating water temperature change is obtained according to the engine operating time and the basic estimated temperature increase rate.

6. The engine water temperature estimation method according to claim 5, characterized in that: Obtaining the real-time estimated water temperature of the engine according to the initial estimated water temperature and the change in the operating water temperature of the engine includes: The real-time estimated water temperature is the sum of the initial estimated water temperature and the change in the operating water temperature.

7. The engine water temperature estimation method according to claim 1, characterized in that: Before the step of obtaining the real-time estimated water temperature of the engine according to the initial estimated water temperature and the change in the running water temperature of the engine, the method includes: Obtain vehicle model information, including whether the vehicle is equipped with a two-way water temperature sensor; If the vehicle includes the two-way water temperature sensor, the circulation state of the engine cooling liquid is obtained according to the temperature of the two-way water temperature sensor and the ambient temperature, and the circulation state includes a large circulation and a small circulation; If the circulation state is the small circulation, the real-time estimated water temperature is the sum of the initial estimated water temperature and the running water temperature change; If the circulation state is the large circulation, the real-time estimated water temperature is the temperature of the two-way water temperature sensor.

8. The engine water temperature estimation method according to claim 7, characterized in that: According to the temperature of the two-way water temperature sensor and the ambient temperature, the circulation state of the engine cooling liquid is obtained, and the circulation state includes a large circulation and a small circulation, including: Obtaining the difference between the temperature of the two-way water temperature sensor and the ambient temperature; If the difference is greater than a first temperature threshold, the cycle state is a large cycle; If the difference is not greater than the first temperature threshold, the cycle state is a small cycle.

9. The engine water temperature estimation method according to claim 7, characterized in that: If the vehicle is not equipped with the two-way water temperature sensor, the real-time estimated water temperature is the sum of the initial estimated water temperature and the operating water temperature change.

10. The engine water temperature estimation method according to claim 9, characterized in that: If the vehicle model is not equipped with the two-way water temperature sensor, after obtaining the real-time estimated water temperature, the real-time estimated water temperature is also verified, and the verification includes: Get the large circulation water temperature when the engine large circulation is fully opened; Comparing the real-time estimated water temperature with the large circulation water temperature; If the real-time estimated water temperature is not greater than the large circulation water temperature, the real-time estimated water temperature is used as the actual real-time water temperature; If the real-time estimated water temperature is greater than the large circulation water temperature, then calculating the temperature difference between the real-time estimated water temperature and the large circulation water temperature; If the temperature difference is not greater than a second temperature threshold, turning on the radiator fan; If the temperature difference is greater than a second temperature threshold, the engine circulation water circuit and the air conditioning heater water circuit are connected in series, and the real-time estimated water temperature is corrected with the water temperature of the air conditioning heater water circuit, and is output as the actual real-time water temperature.

11. The engine water temperature estimation method according to claim 10, characterized in that: If the temperature difference is greater than the second temperature threshold, the engine circulation water path and the air conditioning heater water path are connected in series, and the water temperature of the air conditioning heater water path is used as the real-time estimated water temperature and output as the actual real-time water temperature, and further includes: If the actual real-time water temperature is not higher than the large circulation water temperature, the engine circulation water circuit and the air conditioning heating circuit are disconnected, and the real-time estimated water temperature and the large circulation water temperature are continuously compared.

12. The engine water temperature estimation method according to claim 1, characterized in that: After receiving the engine main water temperature sensor failure signal step, including: Obtain vehicle model information, including whether the vehicle is equipped with a two-way water temperature sensor; If the vehicle is equipped with two water temperature sensors, obtain the temperatures of the two water temperature sensors; Determining the circulation state of the engine according to the temperature of the two-way water temperature sensor; If the circulation state is large circulation, the temperature of the two-way water temperature sensor is used as the real-time estimated water temperature; If the cycle state is a small cycle, the process enters a step of obtaining the initial water temperature of the engine according to the state of the engine until the real-time estimated water temperature of the engine is obtained.

13. An engine control method for continuing to control the engine after the engine main water temperature sensor fails, characterized in that: include: The engine water temperature estimation method according to any one of claims 1 to 12 is used to obtain the engine water temperature estimation temperature, and the engine main water temperature sensor is replaced by the engine water temperature estimation temperature to control the engine operation and reduce the vehicle power output to half.

14. An engine water temperature estimation device, characterized in that: The device comprises: A receiving module, used for receiving a failure signal of a main water temperature sensor of an engine; An initial water temperature acquisition module, used to acquire the initial water temperature of the engine according to the state of the engine; An initial estimated water temperature acquisition module, used to obtain an initial estimated water temperature of the engine according to the initial water temperature and a change in the static water temperature of the engine; The real-time estimated water temperature acquisition module is used to obtain the real-time estimated water temperature of the engine according to the initial estimated water temperature and the change in the operating water temperature of the engine.

15. A vehicle, characterized in that: include: one or more processors; A storage device for storing one or more programs, which, when executed by the one or more processors, enables the vehicle to implement the engine water temperature estimation method as described in any one of claims 1 to 12.

16. A computer-readable storage medium, characterized in that: Computer-readable instructions are stored thereon, and when the computer-readable instructions are executed by a processor of a computer, the computer is caused to execute the engine water temperature estimation method according to any one of claims 1 to 12.

Images