阅读说明：本技术 干式离合器的温度估计方法及装置 (Temperature estimation method and device for dry clutch ) 是由 王林 张霏霏 顾铮珉 刘帅 张永磊 于 2019-08-26 设计创作，主要内容包括：本发明提供的干式离合器的温度估计方法及装置,根据控制器断电休眠持续时间的长短不同,利用不同的方式确定干式离合器各个核心部件在控制器在上电时的初始工作温度；然后根据干式离合器运行时,各个核心部件的热传递,确定各个核心部件的实时工作温度。通过本方案对干式离合器的实时工作温度进行估计,提高了离合器控制的精准度,进而改善了车辆换挡品质和混合动力模式切换品质,以及提高了行车安全。(According to the temperature estimation method and device of the dry clutch, the initial working temperature of each core component of the dry clutch when the controller is powered on is determined in different modes according to different power-off dormancy duration times of the controller; a real-time operating temperature of each core component is then determined based on the heat transfer of each core component during operation of the dry clutch. By estimating the real-time working temperature of the dry clutch according to the scheme, the accuracy of clutch control is improved, the gear shifting quality of the vehicle and the switching quality of a hybrid power mode are improved, and the driving safety is improved.)

1. A method of estimating a temperature of a dry clutch, comprising:

acquiring the power-off dormancy duration of the controller;

judging the magnitude relation between the power-off sleep duration time and a first duration time and a second duration time, wherein the first duration time is shorter than the second duration time;

if the power-off dormancy duration time is longer than the second duration time, determining that the initial temperature of each core component of the dry clutch is equal to the current ambient air temperature, wherein the core components comprise a counter pressure plate, a clutch pull cover and a pressure plate;

if the power-off sleep duration is less than the first duration, determining that the initial temperature of each core component is equal to the temperature of the corresponding core component stored at the start of the power-off sleep;

if the power-off dormancy duration time is not less than the first duration time and not more than the second duration time, calculating the initial working temperature of each core component according to the temperature of each core component stored at the beginning of the power-off dormancy and the heat quantity thermally transferred by each core component in the power-off dormancy duration time;

determining real-time operating temperatures of the core components during operation of the dry clutch based on the initial operating temperatures of the core components and the heat transfer equations of the core components.

2. The method according to claim 1, wherein the step of calculating the initial operating temperature of each core component according to the temperature of each core component stored at the start of the power-off sleep and the heat quantity thermally transferred by each core component during the power-off sleep duration specifically comprises:

dividing the power-off sleep time according to a preset first step length to obtain a 1 st time period, a 2 nd time period, … … and an nth time period;

calculating the temperature of each core component after the 1 st time period according to the temperature of each core component stored at the beginning of the power-off dormancy and the heat quantity thermally transferred by each core component in the 1 st time period;

calculating the temperature of each core component after the M +1 time period according to the temperature of each core component after the M time period and the heat transferred by each core component in the M +1 time period, wherein M is more than or equal to 1 and is less than or equal to n-1;

and taking the temperature of each core component after the nth time period as the initial working temperature of the corresponding core component.

3. The method of claim 1, wherein the step of determining a real-time operating temperature of each core component during operation of the dry clutch based on the initial operating temperature of each core component and a heat transfer equation for each core component comprises:

and calculating heat generated by friction of the clutch, heat absorbed by each core component and heat emitted by each core component according to the initial working temperature of each core component and in each operation step, and calculating the real-time working temperature of each core component.

4. The method of claim 1, prior to the step of obtaining the power down sleep duration of the controller, comprising:

acquiring an ambient air temperature, a first temperature of an engine and a second temperature of the engine, wherein the first temperature is the temperature of the engine at the beginning of power-off dormancy, and the second temperature is the temperature of the engine at the end of the power-off dormancy;

and calculating the temperature decay time of the engine according to the ambient air temperature, the first temperature and the second temperature, and taking the temperature decay time as the power-off sleep duration time.

5. The method of claim 1, prior to the step of obtaining the power down sleep duration of the controller, comprising:

acquiring ambient air temperature, a third temperature and a fourth temperature of a gearbox, wherein the third temperature is the temperature of the gearbox at the beginning of power-off dormancy, and the fourth temperature is the temperature of the gearbox at the end of the power-off dormancy;

and calculating the temperature decay time of the gearbox according to the ambient air temperature, the third temperature and the fourth temperature, and taking the temperature instant time as the power-off dormancy duration time.

6. A temperature estimation device for a dry clutch, comprising:

an acquisition unit for acquiring a power-off sleep duration of the controller;

the judging unit is used for judging the magnitude relation among the power-off sleep duration time, a first duration time and a second duration time, wherein the first duration time is less than the second duration time;

a first initialization unit, configured to determine that an initial temperature of each core component of the dry clutch is equal to a current ambient air temperature if the power-off sleep duration is greater than the second duration, where the core component includes a counter pressure plate, a clutch cover, and a pressure plate;

a second initialization unit, configured to determine that the initial temperature of each core component is equal to a temperature of the corresponding core component stored at the start of the power-off sleep if the power-off sleep duration is less than the first duration;

a third initialization unit, configured to calculate an initial operating temperature of each core component according to a temperature of each core component stored at the start of the power-off sleep and a heat quantity thermally transferred by each core component within the power-off sleep duration, if the power-off sleep duration is not less than the first duration and not greater than the second duration;

and the operation temperature prediction unit is used for determining the real-time operation temperature of each core component in the operation process of the dry clutch according to the initial operation temperature of each core component and the heat transfer equation of each core component.

7. The apparatus according to claim 6, wherein the third initialization unit specifically includes:

the time dividing subunit is used for dividing the power-off sleep time according to a preset first step length to obtain a 1 st time period, a 2 nd time period, … … and an nth time period;

the first temperature prediction subunit is configured to calculate, according to the temperature of each core component stored at the start of the power-off sleep and the heat quantity thermally transferred by each core component in the 1 st time period, a temperature of each core component after the 1 st time period elapses;

the second temperature prediction subunit is used for calculating the temperature of each core component after the M +1 time period according to the temperature of each core component after the M time period and the heat transferred by each core component in the M +1 time period, wherein M is more than or equal to 1 and less than or equal to n-1;

and the temperature determining subunit is used for taking the temperature of each core component after the nth time period as the initial working temperature of the corresponding core component.

8. The apparatus according to claim 6, wherein the temperature prediction unit is specifically configured to:

and calculating heat generated by friction of the clutch, heat absorbed by each core component and heat emitted by each core component according to the initial working temperature of each core component and in each operation step, and calculating the real-time working temperature of each core component.

9. The apparatus of claim 6, further comprising:

the device comprises a first temperature acquisition unit, a second temperature acquisition unit and a control unit, wherein the first temperature acquisition unit is used for acquiring ambient air temperature, a first temperature of an engine and a second temperature of the engine, the first temperature is the temperature of the engine at the beginning of power-off dormancy, and the second temperature is the temperature of the engine at the end of the power-off dormancy;

and the first power-off sleep duration determining unit is used for calculating the temperature decay time of the engine according to the ambient air temperature, the first temperature and the second temperature, and taking the temperature decay time as the power-off sleep duration.

10. The apparatus of claim 6, further comprising:

the second temperature acquisition unit is used for acquiring ambient air temperature, a third temperature and a fourth temperature of the gearbox, wherein the third temperature is the temperature of the gearbox at the beginning of the power-off dormancy, and the fourth temperature is the temperature of the gearbox at the end of the power-off dormancy;

and the second power-off sleep duration determining unit is used for calculating the temperature decay time of the gearbox according to the ambient air temperature, the third temperature and the fourth temperature, and taking the temperature instant time as the power-off sleep duration.

11. A readable storage medium having a program stored thereon, wherein the program, when executed by a processor, performs the steps of the method for estimating the temperature of a dry clutch according to any one of claims 1 to 5.

12. A vehicle comprising a memory for storing a program and a processor for executing the program to carry out the steps of the method of estimating the temperature of a dry clutch according to any one of claims 1 to 5.

Technical Field

The present invention relates to the field of vehicle technologies, and in particular, to a method and an apparatus for estimating a temperature of a dry clutch.

Background

The clutch control of the vehicle is a key technology of the gear shifting control of the automatic gearbox and the hybrid mode switching control. In the clutch control, the temperature of the clutch is continuously changed in the use process because the clutch is continuously opened and closed to generate heat. If the temperature estimation error of the clutch is too large, it may result in inaccurate clutch control. Whether the clutch is controlled quickly and accurately directly influences the gear shifting quality and the hybrid power mode switching quality.

Since the dry clutch is a rotating member, it is difficult to install a temperature sensor to measure temperature. The driven plate of the dry clutch has the highest working temperature, and when the temperature is higher than the highest working temperature, the driven plate is damaged, the friction coefficient of a friction material of the driven plate is rapidly reduced, so that the torque capacity of the clutch is reduced, and the driving safety is influenced. Therefore, a dry clutch temperature calculation method is needed.

Disclosure of Invention

In view of the above, the present invention provides a temperature estimation method and device for a dry clutch, which aim to achieve the purpose of improving the accuracy of clutch control, further improving the shift quality and the hybrid mode switching quality of a vehicle, and improving driving safety by accurately estimating the temperature of the dry clutch.

In order to achieve the above object, the following solutions are proposed:

a method of temperature estimation of a dry clutch, comprising:

acquiring the power-off dormancy duration of the controller;

judging the magnitude relation between the power-off sleep duration time and a first duration time and a second duration time, wherein the first duration time is shorter than the second duration time;

if the power-off dormancy duration time is longer than the second duration time, determining that the initial temperature of each core component of the dry clutch is equal to the current ambient air temperature, wherein the core components comprise a counter pressure plate, a clutch pull cover and a pressure plate;

if the power-off sleep duration is less than the first duration, determining that the initial temperature of each core component is equal to the temperature of the corresponding core component stored at the start of the power-off sleep;

if the power-off dormancy duration time is not less than the first duration time and not more than the second duration time, calculating the initial working temperature of each core component according to the temperature of each core component stored at the beginning of the power-off dormancy and the heat quantity thermally transferred by each core component in the power-off dormancy duration time;

determining real-time operating temperatures of the core components during operation of the dry clutch based on the initial operating temperatures of the core components and the heat transfer equations of the core components.

Optionally, the step of calculating an initial operating temperature of each core component according to the temperature of each core component stored at the start of the power-off sleep and the heat quantity thermally transferred by each core component within the power-off sleep duration includes:

dividing the power-off sleep time according to a preset first step length to obtain a 1 st time period, a 2 nd time period, … … and an nth time period;

calculating the temperature of each core component after the 1 st time period according to the temperature of each core component stored at the beginning of the power-off dormancy and the heat quantity thermally transferred by each core component in the 1 st time period;

calculating the temperature of each core component after the M +1 time period according to the temperature of each core component after the M time period and the heat transferred by each core component in the M +1 time period, wherein M is more than or equal to 1 and is less than or equal to n-1;

and taking the temperature of each core component after the nth time period as the initial working temperature of the corresponding core component.

Optionally, the step of determining the real-time operating temperature of each core component in the operating process of the dry clutch according to the initial operating temperature of each core component and the heat transfer equation of each core component specifically includes:

and calculating heat generated by friction of the clutch, heat absorbed by each core component and heat emitted by each core component according to the initial working temperature of each core component and in each operation step, and calculating the real-time working temperature of each core component.

Optionally, before the step of obtaining the power-off sleep duration of the controller, the method includes:

acquiring an ambient air temperature, a first temperature of an engine and a second temperature of the engine, wherein the first temperature is the temperature of the engine at the beginning of power-off dormancy, and the second temperature is the temperature of the engine at the end of the power-off dormancy;

and calculating the temperature decay time of the engine according to the ambient air temperature, the first temperature and the second temperature, and taking the temperature decay time as the power-off sleep duration time.

Optionally, before the step of obtaining the power-off sleep duration of the controller, the method includes:

acquiring ambient air temperature, a third temperature and a fourth temperature of a gearbox, wherein the third temperature is the temperature of the gearbox at the beginning of power-off dormancy, and the fourth temperature is the temperature of the gearbox at the end of the power-off dormancy;

and calculating the temperature decay time of the gearbox according to the ambient air temperature, the third temperature and the fourth temperature, and taking the temperature instant time as the power-off dormancy duration time.

A temperature estimation device of a dry clutch, comprising:

an acquisition unit for acquiring a power-off sleep duration of the controller;

the judging unit is used for judging the magnitude relation among the power-off sleep duration time, a first duration time and a second duration time, wherein the first duration time is less than the second duration time;

a first initialization unit, configured to determine that an initial temperature of each core component of the dry clutch is equal to a current ambient air temperature if the power-off sleep duration is greater than the second duration, where the core component includes a counter pressure plate, a clutch cover, and a pressure plate;

a second initialization unit, configured to determine that the initial temperature of each core component is equal to a temperature of the corresponding core component stored at the start of the power-off sleep if the power-off sleep duration is less than the first duration;

a third initialization unit, configured to calculate an initial operating temperature of each core component according to a temperature of each core component stored at the start of the power-off sleep and a heat quantity thermally transferred by each core component within the power-off sleep duration, if the power-off sleep duration is not less than the first duration and not greater than the second duration;

and the operation temperature prediction unit is used for determining the real-time operation temperature of each core component in the operation process of the dry clutch according to the initial operation temperature of each core component and the heat transfer equation of each core component.

Optionally, the third initializing unit specifically includes:

the time dividing subunit is used for dividing the power-off sleep time according to a preset first step length to obtain a 1 st time period, a 2 nd time period, … … and an nth time period;

the first temperature prediction subunit is configured to calculate, according to the temperature of each core component stored at the start of the power-off sleep and the heat quantity thermally transferred by each core component in the 1 st time period, a temperature of each core component after the 1 st time period elapses;

the second temperature prediction subunit is used for calculating the temperature of each core component after the M +1 time period according to the temperature of each core component after the M time period and the heat transferred by each core component in the M +1 time period, wherein M is more than or equal to 1 and less than or equal to n-1;

and the temperature determining subunit is used for taking the temperature of each core component after the nth time period as the initial working temperature of the corresponding core component.

Optionally, the temperature prediction unit is specifically configured to:

and calculating heat generated by friction of the clutch, heat absorbed by each core component and heat emitted by each core component according to the initial working temperature of each core component and in each operation step, and calculating the real-time working temperature of each core component.

Optionally, the temperature estimation device for a dry clutch further includes:

the device comprises a first temperature acquisition unit, a second temperature acquisition unit and a control unit, wherein the first temperature acquisition unit is used for acquiring ambient air temperature, a first temperature of an engine and a second temperature of the engine, the first temperature is the temperature of the engine at the beginning of power-off dormancy, and the second temperature is the temperature of the engine at the end of the power-off dormancy;

and the first power-off sleep duration determining unit is used for calculating the temperature decay time of the engine according to the ambient air temperature, the first temperature and the second temperature, and taking the temperature decay time as the power-off sleep duration.

Optionally, the temperature estimation device for a dry clutch further includes:

the second temperature acquisition unit is used for acquiring ambient air temperature, a third temperature and a fourth temperature of the gearbox, wherein the third temperature is the temperature of the gearbox at the beginning of the power-off dormancy, and the fourth temperature is the temperature of the gearbox at the end of the power-off dormancy;

and the second power-off sleep duration determining unit is used for calculating the temperature decay time of the gearbox according to the ambient air temperature, the third temperature and the fourth temperature, and taking the temperature instant time as the power-off sleep duration.

A readable storage medium, having stored thereon a program which, when executed by a processor, carries out the steps of the above-described dry clutch temperature estimation method.

A vehicle comprising a memory for storing a program and a processor for executing the program to carry out the steps of the method of estimating the temperature of a dry clutch as described above.

Compared with the prior art, the technical scheme of the invention has the following advantages:

according to the temperature estimation method and device of the dry clutch, the initial working temperature of each core component of the dry clutch when the controller is powered on is determined in different modes according to different power-off dormancy duration times of the controller; a real-time operating temperature of each core component is then determined based on the heat transfer of each core component during operation of the dry clutch. By estimating the real-time working temperature of the dry clutch according to the scheme, the accuracy of clutch control is improved, the gear shifting quality of the vehicle and the switching quality of a hybrid power mode are improved, and the driving safety is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a dry clutch according to an embodiment of the present invention;

FIG. 2 is a flow chart of a method of estimating the temperature of a dry clutch according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a temperature estimation device of a dry clutch according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The structure of a dry clutch is shown in fig. 1, and comprises a clutch pull cover 1, a pressure plate 2, a driven plate 3, a counter pressure plate 4, a dual-mass flywheel 5 and a clutch housing 6. When the dry clutch works, when the rotating speed of an engine is different from the rotating speed of an input shaft of a gearbox, namely the rotating speed difference exists in the clutch, heat is generated on a friction interface and is transferred to the counter pressure plate 4 and the pressure plate 2; heat to the pressure plate 4 and the pressure plate 2 is transferred to the clutch housing 6 through air convection; meanwhile, the opposite pressure plate 4 transfers heat to the opposite clutch pull cover 1 through heat conduction; the clutch housing 6 transfers heat to the atmosphere by air convection, and thus to the engine and gearbox.

The invention divides the clutch thermal model into an engine, a clutch pull cover 1, a pressure plate 2, a counter pressure plate 4, a clutch shell 6 and a gearbox. The engine and the gearbox are provided with heat sources with temperature sensors, the temperature is known, and the rotating speed difference, the clutch torque, the engine water temperature, the gearbox oil temperature, the ambient air temperature and the vehicle speed are used as boundary condition signals of the whole clutch thermal model.

When the controller is powered off and dormant, temperature signals of the engine and the gearbox cannot be obtained; meanwhile, the temperature of each core component of the dry clutch cannot be calculated in real time. The core idea of the invention is that after the controller is powered on (namely, the power-off dormancy is finished), the initial working temperature of each core component of the dry clutch is determined, and then the temperature of each core component of the dry clutch during working is calculated according to a heat transfer equation. Referring to fig. 2, the method for estimating the temperature of the dry clutch according to the present embodiment will be described in detail below, and may include the steps of:

s21: the power-off sleep duration of the controller is obtained.

In an embodiment of the present invention, the power-off sleep duration of the Controller CAN be directly obtained from a CAN (Controller Area Network) bus. The power-off dormancy duration of the controller can be calculated according to the temperature decay rule of the engine or the gearbox.

The temperature decay equation for an engine is:

wherein, t_offRepresenting the temperature decay time, τ_engRepresents the time constant of engine heat dissipation, T_engIndicating the temperature at the onset of power-off sleep, T_engsavedTemperature, T, at the end of power-off sleep_airIs the ambient air temperature.

When the controller is powered on, the temperature of the engine at the beginning of the power-off dormancy, the temperature of the engine at the end of the power-off dormancy and the ambient air temperature are obtained, and the temperature decay time of the engine is calculated by utilizing a temperature decay formula of the engine. The calculated engine temperature decay time is the power-off dormancy duration of the controller.

And replacing the engine heat dissipation time constant in the temperature attenuation formula of the engine with the gearbox heat dissipation time constant to obtain the temperature attenuation formula of the gearbox. Similarly, when the controller is powered on, the temperature of the gearbox at the beginning of the power-off dormancy, the temperature of the gearbox at the end of the power-off dormancy and the ambient air temperature are obtained, and the temperature decay time of the gearbox is calculated by using a temperature decay formula of the gearbox. The calculated temperature decay time of the transmission is also the power-off sleep duration of the controller.

S22: and judging the magnitude relation between the power-off sleep duration and the first duration and the second duration.

The first duration and the second duration are obtained in advance by means of experimental calibration. The temperature of each core component of the dry clutch changes less during a period of time after the onset of the power down sleep than the corresponding core component temperature stored at the onset of the power down sleep, the period of time being determined to be a first duration of time. After a certain period of time has elapsed following the loss of power to sleep, the temperature of the various core components of the dry clutch have decayed to coincide with the ambient air temperature, which is determined to be a second duration of time. The first duration is less than the second duration.

S23: if the power-off sleep duration is greater than the second duration, an initial temperature of each core component of the dry clutch is determined to be equal to a current ambient air temperature.

In one embodiment of the invention, the core components are a counter pressure plate, a clutch pull cover and a pressure plate.

S24: if the power-off sleep duration is less than the first duration, an initial temperature of each core component of the dry clutch is determined to be equal to a temperature of the corresponding core component stored at the beginning of the power-off sleep.

Determining that the initial temperature of each core component of the dry clutch is equal to the temperature of the corresponding core component stored at the beginning of the power-off sleep, specifically: determining that the initial temperature of the counter pressure plate is equal to the temperature of the counter pressure plate stored at the beginning of the power-off dormancy; determining that the initial temperature of the platen is equal to the temperature of the platen stored at the beginning of the power-off sleep; it is determined that the initial temperature of the clutch pull cover is equal to the stored temperature of the clutch pull cover at the start of the power-off sleep. It should be noted that the temperature of the core component initially stored in the power-off sleep mode is the real-time operating temperature of the core component.

S25: and if the power-off dormancy duration time is not less than the first duration time and not more than the second duration time, calculating the initial working temperature of each core component according to the temperature of each core component stored at the beginning of the power-off dormancy and the heat quantity thermally transferred by each core component in the power-off dormancy duration time.

S26: and determining the real-time working temperature of each core component in the working process of the dry clutch according to the initial working temperature of each core component and the heat transfer equation of each core component.

Each mass thermal state equation isWhere m is the mass of an object, Cp is the specific heat capacity of the object, dT is the temperature change of the object, and Q is the heat of conduction and/or convection.

And calculating heat generated by friction of the clutch, heat absorbed by each core component and heat emitted by each core component according to the initial working temperature of each core component and in combination with each operation step length to obtain the real-time working temperature of each core component.

The heat transfer equation to the platen is:

wherein Ccp_mIs the specific heat capacity to the platen material, m_cpIt is the quality of the pressing disc,is the platen temperature at time k +1,is time k versus platen temperature, Trq_cluIs the clutch torque, ω_slipIs the difference in the rotational speed of the clutch, h_cntrIs the heat transfer coefficient of the platen to the air,is the ambient air temperature at time k, C_cp2engIs the heat conduction coefficient of the pressure plate to the engine, is related to the rotating speed of the engine,is the water temperature of the engine at time k, C_cp2tmIs the heat transfer coefficient from the pressure plate to the gear box, is related to the rotating speed of the engine,is the oil temperature of the gearbox at the moment k, C_cp2ccIs the heat transfer coefficient of the pressure plate to the clutch pull cover,is the clutch pull cap temperature at time k, t_sampleIs the operating step size of the operating thermal model of the controller. The rotating speed of the engine and C are obtained in advance through an experimental mode_cp2eng、C_cp2tmThe corresponding relationship of (a); thus, during the temperature estimation of the dry clutch, the current starting is usedThe machine speed obtains corresponding C_cp2engAnd C_cp2tm。

The heat transfer equation for the clutch pull cover is:

wherein, cc_mIs the specific heat capacity, m, of the material of the clutch pull cover_ccIs the quality of the pull cover of the clutch,is the clutch pull cap temperature at time k +1, h_ccThe heat convection coefficient of the air in the clutch pull cover and the clutch shell is related to the average temperature of the air in the clutch shell and the counter pressure plate and the engine speed C_cc2ppIs the thermal resistance between the clutch pull cover and the pressure plate,is the platen temperature at time k, C_cp2ccIs the thermal resistance between the pressure plate and the clutch pull cover. The average temperature of air in the clutch housing and the average temperature of the pressure plate, the rotating speed of the engine and h are obtained in advance through an experimental mode_ccThe corresponding relation between the two; thus, when the temperature of the dry clutch is estimated, the corresponding h is obtained according to the current engine speed, the air in the clutch shell and the average temperature of the counter pressure plate_cc。

The heat transfer equation for the platen is:

wherein, Cpp_mIs the specific heat capacity of the material of the platen, m_ppIt is the mass of the platen that,is the platen temperature at time k +1, h_ppThe heat convection coefficient of the air in the pressure plate and the clutch shell, and the air and the pressure in the clutch shellAverage temperature of the disc and engine speed dependence, C_pp2ccIs the heat transfer coefficient of the pressure plate to the clutch pull cover. The average temperature of air in the clutch housing and the average temperature of the pressure plate, the rotating speed of the engine and h are obtained in advance through an experimental mode_ppThe corresponding relation between the two; thus, when the temperature of the dry clutch is estimated, the corresponding h is obtained according to the current engine speed, the air in the clutch shell and the average temperature of the counter pressure plate_pp。

Heat transfer equation of clutch housing:

wherein Cp is_AlIs the specific heat capacity of the clutch housing, m_RRIt is the mass of the clutch housing that,is the clutch housing temperature at time k +1,is the clutch housing temperature at time k, h_cntrIs the heat transfer coefficient of the platen to air, h_RIs the thermal convection coefficient of the clutch housing with ambient air, is related to the average temperature of the ambient air and the clutch housing, and the vehicle speed, C_R2engIs the heat transfer coefficient of the clutch housing to the engine, is related to the rotational speed of the engine,is the water temperature of the engine at time k, C_R2tmIs the heat transfer coefficient of the housing to the transmission, is related to the engine speed,is the transmission oil temperature. The rotating speed of the engine and C are obtained in advance through an experimental mode_R2eng、C_R2tmThe corresponding relationship of (a); thus, during the temperature estimation of the dry clutch, the corresponding C is obtained according to the current engine speed_R2engAnd C_R2tm. And obtaining the average temperature of the ambient air and the clutch housing, the vehicle speed, and h in advance through an experimental mode_RThe corresponding relation between the two; thus, when the temperature of the dry clutch is estimated, the corresponding h is obtained according to the average temperature of the current ambient air and the clutch shell and the vehicle speed_R。

The method comprises the following steps of calculating and obtaining initial working temperature of each core component according to the temperature of each core component stored when the power-off dormancy is started and the heat quantity thermally transferred by each core component in the power-off dormancy duration, and specifically comprises the following steps:

dividing the power-off sleep time according to a preset first step length to obtain a 1 st time period, a 2 nd time period, … … and an nth time period;

calculating the temperature of each core component after the 1 st time period according to the temperature of each core component stored at the beginning of the power-off dormancy and the heat quantity thermally transferred by each core component in the 1 st time period;

calculating the temperature of each core component after the M +1 time period according to the temperature of each core component after the M time period and the heat transferred by each core component in the M +1 time period, wherein M is more than or equal to 1 and less than or equal to n-1;

and taking the temperature of each core component after the nth time period as the initial working temperature of the corresponding core component.

The clutch housing temperature calculation during the power-off sleep duration is formulated as:

T_RR(k+1)＝T_RstM(k)-dT_RR2Amb(k)-dT_RR2Eng(k)-dT_RR2TM(k)+dT_CP2RR(k)+dT_CC2RR(k)+dT_PP2RR(k)

wherein, dT_i2j(k)＝(T_i(k)-T_i(k))·τ_ij，τ_ijIs the temperature difference attenuation coefficient between the object i and the object j. T is_RR(k +1) is the clutch housing temperature at time k +1, T_RstM(k) Is the temperature of the clutch housing at time k, T_Eng(k) Is the water temperature of the engine at time k, T_TM(k) Is changed at the k momentFast case oil temperature, T_CP(k) Is time k versus platen temperature, T_cc(k) Clutch pull-cover temperature at time k, T_PP(k) Platen temperature at time k. After the time T elapses between the object i and the object j having the initial temperature difference Δ T, the heat transfer amount is Q, Q is T × Δ T × τ_ij(ii) a Calculating tau corresponding to different temperature differences between the object i and the object j within a step length time in advance through an experimental mode_ij(ii) a Thus, in the temperature estimation of the dry clutch, the corresponding tau is obtained according to the temperature difference between the object i and the object j at the moment k_ij。

The engine water temperature during the power-off sleep duration is calculated by the formula:

T_Eng(k+1)＝(T_Eng(k)-T_R(k))*τ_Eng2R+T_R(k)

wherein, T_R(k) Is the ambient air temperature at time k.

The formula for calculating the gearbox oil temperature in the power-off dormancy duration time is as follows:

T_TM(k+1)＝(T_Eng(k)-T_R(k))*τ_TM2R+T_R(k)

the platen temperature during the power-off sleep duration is calculated as:

T_CP(k+1)＝T_CP(k)-dT_CP2Eng(k)-dT_CP2R(k)-dT_CP2CC(k)

the clutch pull cover temperature calculation formula during the power-off sleep duration is as follows:

T_CC(k+1)＝T_CC(k)+dT_CP2CC(k)-dT_CC2R(k)+dT_PP2CC(k)

the platen temperature during the power-off sleep duration is calculated as:

T_PP(k+1)＝T_PP(k)-dT_PP2CC(k)-dT_PP2R(k)

while, for purposes of simplicity of explanation, the foregoing method embodiments have been described as a series of acts or combination of acts, it will be appreciated by those skilled in the art that the present invention is not limited by the illustrated ordering of acts, as some steps may occur in other orders or concurrently with other steps in accordance with the invention.

The following are embodiments of the apparatus of the present invention that may be used to perform embodiments of the method of the present invention. For details which are not disclosed in the embodiments of the apparatus of the present invention, reference is made to the embodiments of the method of the present invention.

The present embodiment provides a temperature estimation apparatus of a dry clutch, which may include, referring to fig. 3: an acquisition unit 31, a judgment unit 32, a first initialization unit 33, a second initialization unit 34, a third initialization unit 35, and an operating temperature prediction unit 36. Wherein the content of the first and second substances,

an acquisition unit 31 for acquiring a power-off sleep duration of the controller;

a determining unit 32, configured to determine a magnitude relationship between the power-off sleep duration and a first duration and a second duration, where the first duration is smaller than the second duration;

a first initialization unit 33, configured to determine that an initial temperature of each core component of the dry clutch is equal to a current ambient air temperature if the power-off sleep duration is greater than the second duration, where the core component includes a counter pressure plate, a clutch cover, and a pressure plate;

a second initialization unit 34, configured to determine that the initial temperature of each core component is equal to the temperature of the corresponding core component stored at the beginning of the power-off sleep if the power-off sleep duration is less than the first duration;

a third initialization unit 35, configured to calculate, if the power-off sleep duration is not less than the first duration and not greater than the second duration, an initial operating temperature of each core component according to the temperature of each core component stored at the start of the power-off sleep and the heat thermally transferred by each core component in the power-off sleep duration;

and the operation temperature prediction unit 36 is used for determining the real-time operation temperature of each core component in the operation process of the dry clutch according to the initial operation temperature of each core component and the heat transfer equation of each core component.

Optionally, the third initializing unit specifically includes: a time division subunit, a first temperature prediction subunit, a second temperature prediction subunit, and a temperature determination subunit.

The time dividing subunit is used for dividing the power-off sleep time according to a preset first step length to obtain a 1 st time period, a 2 nd time period, … … and an nth time period;

the first temperature prediction subunit is configured to calculate, according to the temperature of each core component stored at the start of the power-off sleep and the heat quantity thermally transferred by each core component in the 1 st time period, a temperature of each core component after the 1 st time period elapses;

the second temperature prediction subunit is used for calculating the temperature of each core component after the M +1 time period according to the temperature of each core component after the M time period and the heat transferred by each core component in the M +1 time period, wherein M is more than or equal to 1 and less than or equal to n-1;

and the temperature determining subunit is used for taking the temperature of each core component after the nth time period as the initial working temperature of the corresponding core component.

Optionally, the temperature prediction unit is specifically configured to: and calculating heat generated by friction of the clutch, heat absorbed by each core component and heat emitted by each core component according to the initial working temperature of each core component and in each operation step, and calculating the real-time working temperature of each core component.

Optionally, the temperature estimation device of the dry clutch further includes: a first temperature acquisition unit and a first power-off sleep duration determination unit.

The device comprises a first temperature acquisition unit, a second temperature acquisition unit and a control unit, wherein the first temperature acquisition unit is used for acquiring ambient air temperature, a first temperature of an engine and a second temperature of the engine, the first temperature is the temperature of the engine at the beginning of power-off dormancy, and the second temperature is the temperature of the engine at the end of the power-off dormancy;

and the first power-off sleep duration determining unit is used for calculating the temperature decay time of the engine according to the ambient air temperature, the first temperature and the second temperature, and taking the temperature decay time as the power-off sleep duration.

Optionally, the temperature estimation device of the dry clutch further includes: a second temperature acquisition unit and a second power-off sleep duration determination unit.

The second temperature acquisition unit is used for acquiring ambient air temperature, a third temperature and a fourth temperature of the gearbox, wherein the third temperature is the temperature of the gearbox at the beginning of the power-off dormancy, and the fourth temperature is the temperature of the gearbox at the end of the power-off dormancy;

a second power-off sleep duration determination unit configured to calculate a temperature decay time of the transmission according to an ambient air temperature, the third temperature, and the fourth temperature, and use the temperature instant time as the power-off sleep duration

The temperature estimation device of the dry clutch provided by the embodiment of the invention can be applied to a controller on a vehicle, such as an ECU (electronic control unit).

An embodiment of the invention provides a vehicle, which comprises a memory and a processor.

The processor is a central processing unit CPU or an application Specific Integrated circuit asic or one or more Integrated circuits configured to implement embodiments of the present invention, etc.

The memory may comprise a high-speed RAM memory, and may further comprise a non-volatile memory (non-volatile memory) or the like, such as at least one disk memory.

Wherein the memory stores a program and the processor can call the program stored in the memory, the program for:

acquiring the power-off dormancy duration of the controller;

judging the magnitude relation between the power-off sleep duration time and a first duration time and a second duration time, wherein the first duration time is shorter than the second duration time;

if the power-off dormancy duration time is longer than the second duration time, determining that the initial temperature of each core component of the dry clutch is equal to the current ambient air temperature, wherein the core components comprise a counter pressure plate, a clutch pull cover and a pressure plate;

if the power-off sleep duration is less than the first duration, determining that the initial temperature of each core component is equal to the temperature of the corresponding core component stored at the start of the power-off sleep;

if the power-off dormancy duration time is not less than the first duration time and not more than the second duration time, calculating the initial working temperature of each core component according to the temperature of each core component stored at the beginning of the power-off dormancy and the heat quantity thermally transferred by each core component in the power-off dormancy duration time;

determining real-time operating temperatures of the core components during operation of the dry clutch based on the initial operating temperatures of the core components and the heat transfer equations of the core components.

The refinement function and the extension function of the program may be referred to as described above.

An embodiment of the present invention further provides a readable storage medium, where the readable storage medium may store a program adapted to be executed by a processor, where the program is configured to:

acquiring the power-off dormancy duration of the controller;

judging the magnitude relation between the power-off sleep duration time and a first duration time and a second duration time, wherein the first duration time is shorter than the second duration time;

if the power-off dormancy duration time is longer than the second duration time, determining that the initial temperature of each core component of the dry clutch is equal to the current ambient air temperature, wherein the core components comprise a counter pressure plate, a clutch pull cover and a pressure plate;

if the power-off sleep duration is less than the first duration, determining that the initial temperature of each core component is equal to the temperature of the corresponding core component stored at the start of the power-off sleep;

if the power-off dormancy duration time is not less than the first duration time and not more than the second duration time, calculating the initial working temperature of each core component according to the temperature of each core component stored at the beginning of the power-off dormancy and the heat quantity thermally transferred by each core component in the power-off dormancy duration time;

determining real-time operating temperatures of the core components during operation of the dry clutch based on the initial operating temperatures of the core components and the heat transfer equations of the core components.

The refinement function and the extension function of the program may be referred to as described above.

The above-described embodiments of the apparatus are merely illustrative, wherein the units described as separate parts may or may not be physically separate, and the parts shown as units may or may not be physical units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.