Double-clutch temperature control method and system and hybrid vehicle

Abstract

The invention provides a double-clutch temperature control method and system and a hybrid power vehicle, the method is used for the hybrid power vehicle with double clutches, and the method comprises the following steps that a gear shifting instruction of a driver is collected, and whether a first gear needs to be switched to a second gear or not is judged according to the gear shifting instruction; the estimated temperature of the second-gear clutch friction plate is obtained from the temperature estimation model; whether the estimated temperature is larger than a preset first temperature threshold value or not is judged; if yes, the vehicle is forbidden to conduct gear shifting through the first gear clutch and the second gear clutch; if not, whether the estimated temperature is larger than a preset second temperature threshold value or not is judged; and if yes, within the preset first time threshold value, speed regulation is conducted through the power input shaft instead of gear shifting through the first gear clutch and the second gear clutch, the method can prevent a clutch friction plate from being over-heated due to sliding friction control gear shifting, and therefore the service life of the clutch is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle gear shifting, in particular to a dual clutch temperature control method, system and hybrid vehicle. BACKGROUND

[0002] Hybrid vehicles can be classified into three types according to the connection mode of hybrid driving, namely, series type, parallel type and series-parallel type. In a series-parallel hybrid vehicle, for example, two electric machines are provided, wherein the first electric machine is rigidly connected with the engine and can assist the engine in starting and speed regulation, and also can charge the battery as a generator, and the second electric machine is connected with the main reducer and can directly output power. In the setting of such a driving system, two gears, i.e., a first gear (low gear) and a second gear (high gear), are provided, and there are a first gear clutch for gear shifting of the first gear and a second gear clutch for gear shifting of the second gear, and the engine can provide energy for the battery through the first electric machine or output power through the two gears.

[0003] In the engine direct drive mode, in order to avoid power interruption during gear shifting (especially switching between the low gear and the high gear), the two clutches complete the speed ratio switching through slip control, so that a large amount of slip work is generated on the clutch friction plate. Especially in the working condition where the upshift and downshift of large throttle are alternately performed for many times, the speed difference and the transmission torque of the clutch are large, and a large amount of heat is generated on the friction plate of the clutch, which may cause clutch failure or reduce the service life of the clutch.

[0004] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present disclosure, and therefore can include information that does not constitute prior art known by those skilled in the art. SUMMARY

[0005] One aspect of the present application aims to solve the technical problem of how to alleviate or avoid the situation that the temperature of the clutch friction plate is too high due to the slip control gear shifting of the dual clutch in the engine direct drive case of the hybrid vehicle.

[0006] In addition, other aspects of the present application also aim to solve or alleviate other technical problems existing in the prior art.

[0007] The present application provides a dual clutch temperature control method, system and hybrid vehicle. Specifically, according to an aspect of the present application, there is provided:

[0008] A dual clutch temperature control method for a hybrid vehicle having a first gear clutch and a second gear clutch, the second gear being higher than the first gear, the dual clutch temperature control method comprising the following steps:

[0009] collecting a shift instruction of a driver, determining whether a shift from a first gear to a second gear or vice versa is needed according to the shift instruction;

[0010] obtaining an estimated temperature of a second gear clutch plate from a temperature estimation model;

[0011] determining whether the estimated temperature is greater than a preset first temperature threshold;

[0012] in response to the estimated temperature being greater than the preset first temperature threshold, prohibiting a shift of the vehicle through the first gear clutch and the second gear clutch;

[0013] in response to the estimated temperature being less than the preset first temperature threshold, determining whether the estimated temperature is greater than a preset second temperature threshold;

[0014] in response to the estimated temperature being greater than the preset second temperature threshold, shifting through the power input shaft speed regulation instead of the first gear clutch and the second gear clutch within a preset first time threshold.

[0015] Optionally, according to an embodiment of the present application, the shifting through the power input shaft speed regulation comprises the following steps:

[0016] obtaining a target gear of the driver according to the shift instruction of the driver;

[0017] determining a target speed of the power input shaft according to the target gear;

[0018] disconnecting a current gear, and regulating the speed of the power input shaft according to the target speed;

[0019] combining the target gear of the driver after the speed regulation is completed.

[0020] Optionally, according to an embodiment of the present application, the first time threshold is positively related to a heat capacity of the second gear clutch calculated according to the temperature estimation model, and is negatively related to a cooling oil flow at the second gear clutch calculated according to the temperature estimation model.

[0021] Optionally, according to an embodiment of the present application, the temperature estimation model calculates the temperature of the second gear clutch according to the following formula:

[0022]

[0023] Q i = μ * T * Δn * A * Δt, C s = (n s * m s * c s ) + (np *m p *c p )

[0024] Wherein, μ is the friction coefficient, T is the torque transmitted by the second gear clutch, Δn is the speed difference between the driving end and the driven end of the second gear clutch, A is the effective friction area of the second gear clutch, Δt is the duration of the slip, Q i is the slip work, is the mass flow of the cooling oil, T o is the oil sump temperature, h is the heat transfer coefficient, A s is the heat dissipation area, Q o is the heat dissipated through the cooling oil, θ k is the average temperature of the friction plate at the current time, C s is the total heat capacity of the system, n s is the number of steel plates, m s is the mass of the steel plate, c s is the specific heat capacity of the steel plate, n p is the number of friction plates, m p is the mass of the friction plate, c p is the specific heat capacity of the friction plate, θ k+1 is the average temperature of the friction plate at the next time.

[0025] Optionally, according to an embodiment of the present application, further comprising the following steps:

[0026] After a preset first time threshold, collecting the speed difference between the driving end and the driven end of the second gear clutch;

[0027] Judging whether the speed difference is within a preset speed difference interval;

[0028] In response to the speed difference being within the preset speed difference interval, switching to the double-clutch slip control shift mode.

[0029] Optionally, according to an embodiment of the present application, further comprising the following steps:

[0030] Collecting the transmitted torque and the speed difference between the driving end and the driven end of the first gear clutch and the second gear clutch during each shift process;

[0031] According to the transmitted torque and the speed difference, calculating the slip work of the first gear clutch and the second gear clutch during the shift process;

[0032] According to the slip work, estimating the service life of the first gear clutch and the second gear clutch.

[0033] Optionally, according to an embodiment of the present application, further comprising the following steps:

[0034] determining whether the slip work is greater than a preset slip work threshold value;

[0035] counting the number of gear shifts whose slip work is greater than the preset slip work threshold value;

[0036] optimizing the gear shift execution parameters in response to the number of gear shifts whose slip work is greater than the preset slip work threshold value being greater than a preset gear shift number threshold value;

[0037] The gear shift execution parameters include a power input shaft speed range, a power input shaft speed adjustment time, and a clutch compression time.

[0038] Optionally, according to an embodiment of the present application, optimizing the gear shift execution parameters includes narrowing the power input shaft speed range and / or reducing the power input shaft speed adjustment time and / or reducing the clutch compression time.

[0039] According to a second aspect of the present application, the present application provides a dual clutch temperature control system for a hybrid vehicle having a first gear clutch and a second gear clutch, the second gear being higher than the first gear, the dual clutch temperature control system comprising:

[0040] a collection module configured to collect a gear shift instruction of a driver;

[0041] a calculation module configured to determine whether a shift from the first gear to the second gear or vice versa is needed according to the gear shift instruction;

[0042] a temperature estimation model configured to calculate an estimated temperature of a second gear clutch friction plate;

[0043] a determination module configured to determine whether the estimated temperature is greater than a preset first temperature threshold value, and in response to the estimated temperature being less than the preset first temperature threshold value, determine whether the estimated temperature is greater than a preset second temperature threshold value;

[0044] a control module configured to, in response to the estimated temperature being greater than the preset first temperature threshold value, prohibit the vehicle from shifting through the first gear clutch and the second gear clutch; and in response to the estimated temperature being greater than the preset second temperature threshold value, shift through a power input shaft speed adjustment instead of the first gear clutch and the second gear clutch within a preset first time threshold value.

[0045] According to a third aspect of the present application, the present application provides a hybrid vehicle comprising a transmission assembly including a first gear clutch and a second gear clutch, the second gear being higher than the first gear, the hybrid vehicle further comprising the dual clutch temperature control system described above.

[0046] The present application has the following advantages at least one of which is:

[0047] 1. The double clutch temperature control method according to one embodiment of the present application can monitor the working state of the clutch friction plate in real time during the slip control shifting of the double clutch, accurately predict the temperature of the clutch friction plate, and adjust the shifting path when the temperature of the clutch friction plate is too high, so as to prevent the temperature of the clutch friction plate from being too high due to the slip control shifting and reduce the service life of the clutch.

[0048] 2. The double clutch temperature control method according to one embodiment of the present application can predict the service life of the clutch according to the slip friction work calculation of each shifting, and optimize the shifting execution parameters according to the prediction, so as to improve the shifting safety and prolong the service life of the clutch. BRIEF DESCRIPTION OF DRAWINGS

[0049] The above and other features of the present application will become apparent from the following description of the embodiments thereof, taken in conjunction with the accompanying drawings which are given by way of illustration and are not intended to be limiting of the present application. In the drawings, like reference numerals refer to like elements through the several views of the drawings, and in which:

[0050] Figure 1 Fig. 1 shows a flow diagram of the double clutch temperature control method according to one embodiment of the present application;

[0051] Figure 2 Fig. 2 shows a module diagram of the double clutch temperature control system according to one embodiment of the present application. DETAILED DESCRIPTION

[0052] It is to be understood that the technical solution according to the present application can be implemented in a variety of ways without departing from the spirit of the present application. Therefore, the following detailed description and drawings are merely illustrative of the technical solution according to the present application, and should not be regarded as limiting the technical solution according to the present application or as limiting the scope of the technical solution according to the present application.

[0053] In the present specification, the orientation terms such as up, down, left, right, front, back, front face, back face, top, bottom, etc. are defined with respect to the structure shown in the drawings, and are relative concepts, so they can change accordingly according to different positions and different use states. Therefore, these or other orientation terms should not be interpreted as limiting terms. In addition, the terms "first", "second", "third" or the like or similar expressions are only used for description and differentiation purposes, and should not be understood as indicating or implying the relative importance of the corresponding components or the sequence or assembly sequence of the components.

[0054] The first aspect of the present application provides a dual clutch temperature control method, which is particularly used to prevent the temperature of the friction plate of the clutch, especially the high speed gear clutch, from being too high when the dual clutch slip control is used to directly drive the low speed gear and the high speed gear in the case of engine direct drive, so as to prolong the service life of the clutch and improve the control accuracy of the clutch. Figure 1 Fig. 1 shows a flowchart of the dual clutch temperature control method according to one embodiment of the present application. The dual clutch temperature control method is used in a hybrid vehicle with a first gear clutch and a second gear clutch. The second gear is higher than the first gear, so the first gear clutch is the low speed gear clutch and the second gear clutch is the high speed gear clutch. The method comprises the following steps:

[0055] S100: Collect the gear shifting instruction of the driver and determine whether the first gear needs to be switched to the second gear or vice versa according to the gear shifting instruction;

[0056] S200: Obtain the estimated temperature of the friction plate of the second gear clutch from a temperature estimation model;

[0057] S300: Determine whether the estimated temperature is greater than a preset first temperature threshold;

[0058] S310: In response to the estimated temperature being greater than the preset first temperature threshold, prohibit the vehicle from shifting through the first gear clutch and the second gear clutch;

[0059] S320: In response to the estimated temperature being less than the preset first temperature threshold, determine whether the estimated temperature is greater than a preset second temperature threshold;

[0060] S400: In response to the estimated temperature being greater than the preset second temperature threshold, shift through the power input shaft speed regulation instead of the first gear clutch and the second gear clutch within a preset first time threshold.

[0061] When the vehicle needs to switch from the first gear to the second gear or vice versa, the vehicle is usually in the case of engine direct drive and the first gear clutch and the second gear clutch need to complete the speed ratio switching through slip control, which makes the friction plates of the two clutches generate a large amount of friction work, resulting in a high temperature of the clutches. In this case, due to the arrangement of the gears and the characteristics of the slip control, the slip work of the high speed gear clutch is generally higher, so its temperature is generally higher than that of the low speed gear clutch. Therefore, in this embodiment, only the estimated temperature of the friction plate of the second gear clutch is obtained to determine whether the temperature of the clutch is too high. The temperature of the friction plate of the first gear clutch is generally lower than the temperature, and the temperature control is performed when the second gear clutch is overheated, so the friction plate of the first gear clutch is generally not overheated.

[0062] In the case that the temperature exceeds the first temperature threshold, the clutch friction plate can have been ablated or have a seizure or sticking failure, at which time the vehicle should be immediately prohibited from shifting through the low gear clutch and the high gear clutch, i.e. the vehicle is maintained at the current gear and no shifting is performed, and the two clutches are completely avoided from continuing to work, to ensure safety. In the case that the temperature is lower than the first temperature threshold and higher than the second temperature threshold, the clutch friction plate has a high temperature, but is not yet significantly failed, at which time shifting is not performed through the slip control of the two clutches to prevent the clutch friction plate from continuing to generate excessive slip work, but is performed through the speed regulation of the power input shaft, and only the first gear clutch is used for a short time to combine and disconnect the power. This process lasts for a first time threshold, and in this time period, the temperature of the second gear clutch is reduced to a safe range below the second temperature threshold, and the next time the low speed gear and the high speed gear are switched, the two clutches can be used for slip control shifting.

[0063] In an embodiment of the present application, the shifting through the speed regulation of the power input shaft comprises the following steps:

[0064] obtaining a target gear of the driver according to a shifting instruction of the driver;

[0065] determining a target speed of the power input shaft according to the target gear;

[0066] disconnecting the current gear and regulating the speed of the power input shaft according to the target speed;

[0067] combining the target gear of the driver after the speed regulation is completed.

[0068] In this embodiment, after the target gear of the driver is determined, the current gear is first disconnected, instead of the slip control of the low speed gear clutch and the high speed gear clutch, to prevent the temperature of the clutch friction plate from continuing to rise. Then the input shaft is regulated to meet the shifting demand of the driver, and when the input shaft reaches the target speed, it is combined to the target gear of the driver, so as to achieve shifting without slip control. In this process, the temperature of the high speed gear clutch can be reduced, and the normal shifting of the driver can be ensured.

[0069] In an embodiment of the present application, the first time threshold is positively related to the heat capacity of the second gear clutch calculated according to the temperature estimation model, and is negatively related to the cooling oil flow at the second gear clutch calculated according to the temperature estimation model.

[0070] When the high-gear clutch has a high thermal capacity, the temperature thereof drops slowly, and a long time is required for the high-gear clutch friction plate to cool down, so the gear shifting should be performed by the power input shaft speed regulation over a long period of time. When the cooling oil flow rate at the high-gear clutch is high, the friction plate can be cooled down quickly, and the gear shifting can be performed by the power input shaft speed regulation over a short period of time. Matching the first time threshold value with the thermal capacity and the cooling oil flow rate of the clutch instead of using a completely fixed time threshold value can match the parameters and working conditions of the clutch to achieve temperature control of the clutch, and is more conducive to individualized temperature reduction for clutches of different models and parameters, and improves the accuracy of temperature control.

[0071] In an embodiment of the present application, the temperature estimation model calculates the temperature of the second-gear clutch according to the following formula:

[0072]

[0073] Q i = μ * T * Δn * A * Δt, C s = (n s *m s *c s ) + (n p *m p *c p )

[0074] Wherein, μ is the friction coefficient, T is the torque transmitted by the second-gear clutch, Δn is the speed difference between the driving end and the driven end of the second-gear clutch, A is the effective friction area of the second-gear clutch, Δt is the duration of the sliding friction, Q i is the sliding friction work, is the cooling oil mass flow rate, T o is the oil sump temperature, h is the heat transfer coefficient, A s is the heat dissipation area, Q o is the heat dissipated by the cooling oil, θ k is the average temperature of the friction plate at the current time, C s is the total heat capacity of the system, n s is the number of steel plates, m s is the mass of the steel plate, c s is the specific heat capacity of the steel plate, n p is the number of friction plates, m p is the mass of the friction plate, c p is the specific heat capacity of the friction plate, θ k+1 is the average temperature of the friction plate at the next time.

[0075] In the temperature estimation model of this embodiment, personalized parameters of the clutch itself are used to estimate the clutch temperature, such as effective friction area of the clutch, number of friction plates, number of steel plates, etc., and the influence of cooling of the friction plates on the temperature of the friction plates is also considered. This temperature estimation model can be applied to clutches of different models, with different performance parameters and cooling methods, and can accurately estimate the temperature values of different clutches through calculation.

[0076] In an embodiment of the present application, the method further comprises the following steps:

[0077] After the first time threshold, the speed difference between the driving end and the driven end of the second gear clutch is collected;

[0078] It is judged whether the speed difference is within the preset speed difference interval;

[0079] In response to the speed difference being within the preset speed difference interval, switching to the double-clutch slip control shifting mode.

[0080] In this embodiment, after the first time threshold, the double-clutch slip control shifting mode is not switched immediately. Instead, it is first judged whether the speed difference (i.e. slip) between the driving end and the driven end of the high gear clutch is within the preset speed difference interval, which can be understood as a safety interval of the slip. Within this safety interval, the slip control of the clutch will not produce too high slip friction power to cause the temperature of the friction plate to rise too high to exceed the second temperature threshold. Therefore, if the slip is within the speed difference interval, the double-clutch slip control shifting can be directly adopted, and if the slip is outside the speed difference interval, the power input shaft speed regulation shifting mode can be considered for a period of time.

[0081] In an embodiment of the present application, the method further comprises the following steps:

[0082] The transmission torque and the speed difference between the driving end and the driven end of the first gear clutch and the second gear clutch during each shifting process are collected;

[0083] The slip friction power of the first gear clutch and the second gear clutch during the shifting process is calculated according to the transmission torque and the speed difference;

[0084] The service life of the first gear clutch and the second gear clutch is estimated according to the slip friction power.

[0085] In this embodiment, not only the temperature of the second gear clutch is controlled, but also the slip of the first gear clutch and the second gear clutch is collected, so that the slip friction work generated during each gear shift is calculated according to the slip. The slip friction work is directly related to the heat generated by the clutch, and also indirectly affects the service life of the clutch. By calculating the slip friction work of the first gear clutch and the second gear clutch during each gear shift, the service life of the clutch can be inferred to understand the state of the clutch in advance before the clutch fails.

[0086] In one embodiment of the present application, the method further comprises the steps of:

[0087] determining whether the slip friction work is greater than a preset slip friction work threshold value;

[0088] counting the number of gear shifts with the slip friction work greater than the preset slip friction work threshold value;

[0089] optimizing the gear shift execution parameters in response to the number of gear shifts with the slip friction work greater than the preset slip friction work threshold value being greater than a preset gear shift number threshold value;

[0090] The gear shift execution parameters include a power input shaft speed range, a power input shaft speed regulation time, and a clutch compression time.

[0091] In this embodiment, the number of gear shifts with the slip friction work greater than the slip friction work threshold value is counted. In the case where the slip friction work is greater than the preset slip friction work threshold value, the clutch will generate a larger amount of heat, thereby having a greater impact on the service life of the clutch. After multiple occurrences of such large slip friction work, the adverse effects on the clutch can be too great, directly leading to a significant reduction in the service life of the clutch. In order to extend the service life of the clutch as much as possible and improve the control accuracy of the clutch, the gear shift execution parameters of the clutch can be optimized after a certain number of such gear shifts. By reducing the power input shaft speed range and the power input shaft speed regulation time, the consumption of the clutch during power input shaft speed regulation can be reduced. By reducing the clutch compression time, the slip friction work of the clutch during gear shift can be reduced. Therefore, in one embodiment of the present application, optimizing the gear shift execution parameters includes narrowing the power input shaft speed range and / or reducing the power input shaft speed regulation time and / or reducing the clutch compression time.

[0092] A second aspect of the present application proposes a dual clutch temperature control system. Referring to Figure 2 which shows a block diagram of a dual clutch temperature control system 100 according to one embodiment of the present application. The dual clutch temperature control system 100 is used in a hybrid vehicle having a first gear clutch and a second gear clutch, the second gear being higher than the first gear, and the dual clutch temperature control system 100 comprises:

[0093] a collection module 1 configured to collect a shift instruction of a driver;

[0094] a calculation module 2 configured to determine whether a shift from a first gear to a second gear or vice versa is needed according to the shift instruction;

[0095] a temperature estimation model 3 configured to calculate an estimated temperature of a second gear clutch plate;

[0096] a determination module 4 configured to determine whether the estimated temperature is greater than a preset first temperature threshold, and in response to the estimated temperature being less than the preset first temperature threshold, determine whether the estimated temperature is greater than a preset second temperature threshold;

[0097] a control module 5 configured to, in response to the estimated temperature being greater than the preset first temperature threshold, prohibit a vehicle to shift through the first gear clutch and the second gear clutch; and in response to the estimated temperature being greater than the preset second temperature threshold, shift through the power input shaft speed regulation instead of the first gear clutch and the second gear clutch within a preset first time threshold.

[0098] In an embodiment of the present application, the calculation module 2 obtains a driver target gear according to the shift instruction of the driver; determines a target speed of the power input shaft according to the target gear; and the control module 5 controls the shift execution unit to disconnect the current gear, and regulates the speed of the power input shaft according to the target speed; and combines the driver target gear after the speed regulation is completed.

[0099] In an embodiment of the present application, the collection module 1 collects a speed difference between a driving end and a driven end of the second gear clutch after a preset first time threshold; the determination module 2 determines whether the speed difference is within a preset speed difference interval; and in response to the speed difference being within the preset speed difference interval, the control module 5 controls the shift execution unit to switch to a double clutch slip control shift mode.

[0100] In an embodiment of the present application, the collection module 1 collects a transmission torque and a speed difference between a driving end and a driven end of the first gear clutch and the second gear clutch in each shift process; the calculation module 2 calculates a slip friction work of the first gear clutch and the second gear clutch in the shift process according to the transmission torque and the speed difference; and calculates a service life of the first gear clutch and the second gear clutch according to the slip friction work.

[0101] In one embodiment of the present application, the determining module 4 determines whether the slip work is greater than a preset slip work threshold value; the calculating module 2 counts the number of gear shifts with the slip work greater than the preset slip work threshold value; and the control module 5 optimizes the gear shift execution parameters in response to the number of gear shifts with the slip work greater than the preset slip work threshold value being greater than a preset gear shift number threshold value; the gear shift execution parameters include the power input shaft speed range, the power input shaft speed adjusting time and the clutch pressing time.

[0102] In one embodiment of the present application, the control module 5 optimizing the gear shift execution parameters includes narrowing the power input shaft speed range and / or reducing the power input shaft speed adjusting time and / or reducing the clutch pressing time.

[0103] The third aspect of the present application provides a hybrid vehicle, which comprises a transmission assembly including a first gear clutch and a second gear clutch, the second gear being higher than the first gear, and further comprises the double clutch temperature control system as described above.

[0104] In summary, the double clutch temperature control method according to one embodiment of the present application can monitor the working state of the clutch friction plate in real time during the double clutch slip control gear shift, accurately predict the temperature of the clutch friction plate, and adjust the gear shift path when the temperature of the clutch friction plate is too high, thereby meeting the gear shift demand of the driver while preventing the temperature of the clutch friction plate from being too high due to the slip control gear shift and reducing the service life of the clutch.

[0105] It should be understood that all the above preferred embodiments are exemplary but not limiting, and various modifications or variations of the above described specific embodiments made by those skilled in the art under the concept of the present application shall fall within the legal protection scope of the present application.

Claims

1. A dual clutch temperature control method, characterized by, A dual clutch temperature control method for a hybrid vehicle having a first gear clutch and a second gear clutch, the second gear being higher than the first gear, the method comprising the steps of: acquiring a driver's shift instruction, and determining whether a shift from the first gear to the second gear or vice versa is needed according to the shift instruction; acquiring an estimated temperature of the second gear clutch from a temperature estimation model; determining whether the estimated temperature is greater than a preset first temperature threshold; in response to the estimated temperature being greater than the preset first temperature threshold, prohibiting the vehicle from shifting through the first gear clutch and the second gear clutch; in response to the estimated temperature being less than the preset first temperature threshold, determining whether the estimated temperature is greater than a preset second temperature threshold; in response to the estimated temperature being greater than the preset second temperature threshold, shifting through the power input shaft speed regulation instead of the first gear clutch and the second gear clutch within a preset first time threshold.

2. The dual clutch temperature control method of claim 1, wherein, The shifting through the power input shaft speed regulation comprises the steps of: acquiring a driver's target gear according to the driver's shift instruction; determining a target speed of the power input shaft according to the target gear; disconnecting the current gear, and regulating the speed of the power input shaft according to the target speed; combining the driver's target gear after the speed regulation is completed.

3. The dual clutch temperature control method of claim 1, wherein, The first time threshold is positively related to the heat capacity of the second gear clutch calculated according to the temperature estimation model, and is negatively related to the cooling oil flow at the second gear clutch calculated according to the temperature estimation model.

4. The dual clutch temperature control method of claim 1, wherein, The temperature estimation model calculates the temperature of the second gear clutch according to the following formula: Q i = μ * T * Δn * A * Δt, C s = (n s *m s *c s ) + (n p *m p *c p ) Wherein, μ is the friction coefficient, T is the torque transmitted by the second gear clutch, Δn is the speed difference between the driving end and the driven end of the second gear clutch, A is the effective friction area of the second gear clutch, Δt is the duration of the sliding friction, Q i is the sliding friction work, is the cooling oil mass flow, T o is the oil sump temperature, h is the heat transfer coefficient, A s is the heat dissipation area, Q o is the heat dissipated through the cooling oil, θ k is the average temperature of the friction plate at the current moment, C s is the total heat capacity of the system, n s is the number of steel plates, m s is the mass of the steel plate, c s is the specific heat capacity of the steel plate, n p is the number of friction plates, m p is the mass of the friction plate, c p is the specific heat capacity of the friction plate, θ k+1 is the average temperature of the friction plate at the next moment.

5. The dual clutch temperature control method of claim 1, wherein, The method further comprises the steps of: after the preset first time threshold, acquiring the speed difference between the driving end and the driven end of the second gear clutch; determining whether the speed difference is within a preset speed difference interval; in response to the speed difference being within the preset speed difference interval, switching to a dual clutch slip control shift mode.

6. The dual clutch temperature control method of claim 1, wherein, The method further comprises the steps of: acquiring the transmission torque and the speed difference between the driving end and the driven end of the first gear clutch and the second gear clutch during each shift; calculating the slip work of the first gear clutch and the second gear clutch during the shift according to the transmission torque and the speed difference; estimating the service life of the first gear clutch and the second gear clutch according to the slip work.

7. The dual clutch temperature control method of claim 6, wherein, The method further comprises the steps of: determining whether the slip work is greater than a preset slip work threshold; counting the shifts with the slip work greater than the preset slip work threshold; in response to the number of shifts with the slip work greater than the preset slip work threshold being greater than a preset shift number threshold, optimizing shift execution parameters; The shift execution parameters include the power input shaft speed range, the power input shaft speed regulation time and the clutch compression time.

8. The dual clutch temperature control method of claim 7, wherein, The optimization of the shift execution parameters includes narrowing the power input shaft speed range and / or reducing the power input shaft speed regulation time and / or reducing the clutch compression time.

9. A dual clutch temperature control system characterized by, A dual clutch temperature control system for a hybrid vehicle having a first gear clutch and a second gear clutch, the second gear being higher than the first gear, the system comprising: an acquisition module that acquires a driver's shift instruction; a computing module configured to determine whether a shift from the first gear to the second gear or vice versa is required based on the shift instruction; a temperature estimation model configured to calculate an estimated temperature of the second gear clutch plate; a determining module configured to determine whether the estimated temperature is greater than a first preset temperature threshold, and in response to the estimated temperature being less than the first preset temperature threshold, determine whether the estimated temperature is greater than a second preset temperature threshold; a control module configured to, in response to the estimated temperature being greater than the first preset temperature threshold, prohibit the vehicle from shifting through the first gear clutch and the second gear clutch; and in response to the estimated temperature being greater than the second preset temperature threshold, within a first preset time threshold, shift through the power input shaft speed regulation instead of the first gear clutch and the second gear clutch.

10. A hybrid vehicle characterized by comprising: The hybrid vehicle includes a transmission assembly including a first gear clutch and a second gear clutch, the second gear being higher than the first gear, and the hybrid vehicle further includes the dual clutch temperature control system according to claim 9.

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