Engine start control method and device for hybrid vehicle

Abstract

The application relates to an engine starting control method and device for a hybrid vehicle, which comprises the following steps: after completing the current starting of the engine, if it is judged that the starting time data meets the predetermined condition, a first coefficient corresponding to the working temperature at the current starting of the engine is calculated according to the starting time data; if it is judged that the first coefficient determines that the clutch torque capacity adaptation needs to be adjusted, the clutch torque capacity adaptation corresponding to the working temperature is adjusted according to the first coefficient and a predetermined compensation amount, and the adjusted clutch torque capacity adaptation and the working temperature are stored correspondingly, wherein the adjusted clutch torque capacity adaptation is used for the next starting of the engine corresponding to the working temperature, so that the clutch torque capacity adaptation can be adjusted frequently, the clutch torque capacity adaptation can converge at different temperatures, and the driving performance is improved.

Description

Technical Field

[0001] This application relates to the field of hybrid vehicle technology, and in particular to an engine start control method and device for a hybrid vehicle. Background Technology

[0002] In related technologies, during the engine start-up process of a hybrid electric vehicle, the clutch torque capacity increases at a reasonable rate to a constant clutch torque capacity, and the clutch partially engages to transmit the constant clutch torque capacity to the engine, thereby adjusting the engine speed to a threshold speed lower than the drive motor speed. Summary of the Invention

[0003] In view of this, this application proposes an engine start control method and device for hybrid electric vehicles.

[0004] To address the aforementioned technical problems, according to one aspect of this application, an engine start-up control method for a hybrid electric vehicle is provided. The hybrid electric vehicle includes an engine, a drive motor, and a clutch disposed between the engine and the drive motor. The engine start-up control method includes: a first judgment step, used to determine whether the start-up time data of the engine in this start-up meets a predetermined condition after the engine has been started; a first calculation step, used to calculate a first coefficient corresponding to the operating temperature of the engine at the time of this start-up based on the start-up time data if the start-up time data meets the predetermined condition; a second judgment step, used to determine whether it is necessary to adjust the clutch torque capacity adaptation amount corresponding to the engine and the operating temperature based on the first coefficient; and an adjustment step, used to adjust the clutch torque capacity adaptation amount corresponding to the operating temperature based on the first coefficient and a predetermined compensation amount if it is determined that the clutch torque capacity adaptation amount needs to be adjusted, and to store the adjusted clutch torque capacity adaptation amount and the operating temperature accordingly, wherein the adjusted clutch torque capacity adaptation amount is used for the next start of the engine corresponding to the operating temperature.

[0005] According to another aspect of this application, an engine start control device for a hybrid electric vehicle is provided. The hybrid electric vehicle includes an engine, a drive motor, and a clutch disposed between the engine and the drive motor. The engine start control device includes: a first judgment module, configured to determine whether the start time data of the engine in the current start meets a predetermined condition after the engine is started; a first calculation module, configured to calculate a first coefficient corresponding to the operating temperature of the engine at the time of the current start based on the start time data if the start time data meets the predetermined condition; a second judgment module, configured to determine whether it is necessary to adjust the clutch torque capacity adaptation amount corresponding to the engine and the operating temperature based on the first coefficient; and an adjustment module, configured to adjust the clutch torque capacity adaptation amount corresponding to the operating temperature based on the first coefficient and a predetermined compensation amount if it is determined that the clutch torque capacity adaptation amount needs to be adjusted, and to store the adjusted clutch torque capacity adaptation amount and the operating temperature accordingly, wherein the adjusted clutch torque capacity adaptation amount is used for the next start of the engine corresponding to the operating temperature.

[0006] According to the hybrid electric vehicle engine start control method and apparatus of this application, after the engine starts, it is determined whether the start time data of the engine in this start meets a predetermined condition; if it is determined that the start time data meets the predetermined condition, a first coefficient corresponding to the operating temperature of the engine at the time of this start is calculated based on the start time data; it is determined based on the first coefficient whether it is necessary to adjust the clutch torque capacity adaptation amount corresponding to the engine and the operating temperature; and if it is determined that it is necessary to adjust the clutch torque capacity adaptation amount, the clutch torque capacity adaptation amount corresponding to the operating temperature is adjusted based on the first coefficient and a predetermined compensation amount, and the adjusted clutch torque capacity adaptation amount and the operating temperature are stored accordingly, wherein the adjusted clutch torque capacity adaptation amount is used for the next start of the engine corresponding to the operating temperature. This avoids frequent adjustments to the clutch torque capacity adaptation amount, effectively preventing unstable starting torque caused by frequent adjustments, and thus enhancing the robustness of the clutch torque capacity adaptation amount adjustment. Furthermore, since frequent adjustments to the clutch torque capacity can be avoided, frequent changes in the data in the storage device caused by frequent adjustments to the clutch torque capacity can be effectively avoided, thereby reducing the number of erase / write cycles of the storage device and extending its lifespan.

[0007] On the other hand, since the engine operating temperature is taken into account during the determination of the clutch torque capacity adaptation, the clutch torque capacity adaptation can converge under different operating temperatures, eliminating the influence of operating temperature on the clutch torque capacity adaptation, thereby improving the vehicle's driving performance.

[0008] Other features and aspects of the invention will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0009] The accompanying drawings, which are included in and form part of this specification, illustrate exemplary embodiments, features, and aspects of the invention together with the specification and serve to explain the principles of the invention.

[0010] Figure 1 This is a schematic diagram of the powertrain structure of a hybrid electric vehicle in related technologies.

[0011] Figure 2 This is a schematic diagram of the engine start-up process of a hybrid electric vehicle with a P2 module in related technologies.

[0012] Figure 3 This is a schematic diagram of the engine start-up process of a hybrid electric vehicle with a P2 module in related technologies.

[0013] Figure 4 This is a schematic diagram illustrating the start-up time of the engine start-up process in a hybrid electric vehicle with a P2 module in related technologies.

[0014] Figure 5 This is a schematic diagram illustrating the changes in clutch torque capacity adaptation involved in the self-learning process in related technologies.

[0015] Figure 6 This is a flowchart illustrating an engine start-up control method for a hybrid electric vehicle according to an exemplary embodiment.

[0016] Figure 7 This is a schematic diagram illustrating the convergence of clutch torque capacity adaptation at different temperatures during the self-learning process of the engine start control method after applying this embodiment and related technologies.

[0017] Figure 8 This is a schematic diagram illustrating the value of the current temperature Dx according to an exemplary embodiment.

[0018] Figure 9 This is a schematic diagram comparing the changes in clutch torque capacity adaptation during the self-learning process of the engine start control method after applying this embodiment and related technologies.

[0019] Figure 10This is a block diagram illustrating an engine start control device for a hybrid electric vehicle according to an exemplary embodiment. Detailed Implementation

[0020] Various exemplary embodiments, features, and aspects of the present invention will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0021] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0022] Furthermore, to better illustrate the present invention, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that the present invention can be practiced without certain specific details. In other instances, methods, means, elements, and circuits well known to those skilled in the art have not been described in detail in order to highlight the spirit of the invention.

[0023] As described in the background section, during the engine start-up process of a hybrid electric vehicle, the clutch torque capacity increases at a reasonable rate to a constant clutch torque capacity, and the clutch partially engages to transmit this constant clutch torque capacity to the engine, thereby adjusting the engine speed to a threshold speed below the drive motor speed.

[0024] In some cases, such as when the engine's frictional torque is higher than average due to low coolant temperature, or when the actual clutch torque is lower than required due to severe wear, the difference between the resultant force used to pull the engine speed—that is, the clutch torque and the engine's frictional torque—is less than normal. This results in a longer time required for the engine to reach the threshold speed, thus delaying the total engine start-up time.

[0025] To address the aforementioned issues, related technologies involve increasing the clutch torque capacity used for the current start if the engine start time exceeds an acceptable limit; conversely, decreasing the clutch torque capacity used for the current start if the engine start time falls short of the acceptable limit, and storing this clutch torque capacity in a storage device such as an EEPROM for use on the next start. In this way, upon the next start, the stored clutch torque capacity is retrieved, and the required clutch torque capacity is calculated based on this retrieved value, ensuring that the engine speed reaches the threshold speed promptly.

[0026] However, even when the starting time of the engine is slightly longer or shorter than acceptable due to some unforeseen factors (such as fluctuations in engine coolant temperature or clutch temperature), it is still necessary to reduce or increase the clutch torque capacity adaptation. This causes the clutch torque capacity adaptation to be used for the next engine start to change frequently, resulting in unstable starting torque and frequent changes in the data in the storage device, thereby increasing the number of times the storage device can be erased and rewritten, and thus shortening the life of the storage device.

[0027] To better understand the above issues, the following will combine... Figures 1 to 5 Let's elaborate on that.

[0028] Figure 1 This is a schematic diagram of the powertrain structure of a hybrid electric vehicle in related technologies. For example... Figure 1 As shown, the hybrid vehicle includes an engine, a P2 module, and a gearbox. The P2 module includes a K0 clutch and a drive motor. The P2 module is located between the engine and the gearbox, and the K0 clutch is located between the engine and the drive motor.

[0029] Figure 2 This is a schematic diagram of the engine start-up process in a hybrid electric vehicle with a P2 module, as described in related technologies. Figure 2 As shown, the engine start-up process goes through stages P1, P2 and P3 in sequence. During the entire engine start-up process, the engine state (i.e. the operating state issued by the engine controller) is successively the stop state, start state and run state.

[0030] like Figure 2 As shown, in stage P1, the clutch torque capacity increases at a reasonable rate to a constant clutch torque capacity M, and the k0 clutch partially engages to transmit this constant clutch torque capacity to the engine, thereby adjusting the engine speed to a threshold speed lower than the drive motor speed. During this period, since the engine has not yet started, the engine torque capacity is 0. When the engine speed is higher than this threshold speed, stage P2 is entered.

[0031] In stage P2, the engine starts (ignites), and the clutch torque capacity decreases at a reasonable rate until the clutch is fully disengaged, thus preventing vehicle jerking caused by subsequent direct clutch engagement. Since the engine is already running, the engine torque capacity is not zero, and the engine speed is adjusted based on this torque capacity.

[0032] In stage P3, the clutch torque capacity increases at a reasonable rate, the k0 clutch partially engages to transmit the clutch torque capacity to the engine, thereby adjusting the engine speed to be close to the drive motor speed. When the engine speed and the drive motor speed are basically the same, the k0 clutch is fully engaged, and the engine speed curve and the drive motor speed curve basically overlap, that is, engine speed synchronization processing is performed.

[0033] However, in certain situations, such as when the engine's frictional torque is higher than average due to low coolant temperature, or when the actual torque of the K0 clutch is less than required due to severe wear, the resultant force required to raise the engine speed (this resultant force = actual torque of the K0 clutch - engine frictional torque) becomes less than normal. This results in a longer time required for the engine to reach the threshold speed, thus delaying the total engine start-up time. Even worse, in some extreme cases, the engine's frictional torque may exceed the actual torque of the K0 clutch, making it impossible to raise the engine speed and thus preventing successful engine start-up.

[0034] To ensure that the engine speed can reach the threshold speed in a timely manner, it is advisable to appropriately increase the constant clutch torque capacity M. (Illustratively speaking...) Figure 3 This is a schematic diagram of the engine start-up process of a hybrid electric vehicle with a P2 module in related technologies, such as... Figure 3 As shown, clutch k0 uses a larger clutch torque capacity M1 to increase engine speed. Specifically, in stage P1, the constant clutch torque capacity M is increased by a clutch torque capacity adaptation amount ΔM calculated through a self-learning strategy to obtain a larger adjusted clutch torque capacity M1 (i.e., M1 = M + ΔM). It is evident that after using the self-learning strategy, as the clutch torque capacity increases from M to M1, the engine speed rises faster and can reach the threshold speed in a shorter time.

[0035] In related technologies, the self-learning strategy includes: if the engine starts for too long in this start-up, the clutch torque capacity adaptation for this start-up is increased, and the increased clutch torque capacity adaptation is used as the clutch torque capacity adaptation for the next start-up; if the engine starts for too short in this start-up, the clutch torque capacity adaptation for this start-up is decreased, and the decreased clutch torque capacity adaptation is used as the clutch torque capacity adaptation for the next start-up.

[0036] In one possible implementation, if the engine starts too long during the current start-up, the formulas ΔM'=ΔM+ΔML and ΔML=KL*(T3-(T2+△t2)) / t0 are used to calculate and store the clutch torque capacity adaptation amount ΔM' to be used for the next engine start-up. ΔM is the clutch torque capacity adaptation amount used for the current engine start-up, ΔML is the torque capacity to be increased, KL is the torque adjustment coefficient, T2 is the acceptable engine start-up time, T2+△t2 represents the upper limit of the start-up time, T3 is the start-up time of the current engine start-up, and t0 is the time unit.

[0037] In one possible implementation, if the engine start-up time in this start is too short, the formulas ΔM'=ΔM-ΔMs and ΔMs=Ks*(T2-△t1-T1) / t0 are used to calculate and store the clutch torque capacity adaptation amount ΔM' to be used for the next engine start. ΔM is the clutch torque capacity adaptation amount used for the current engine start, ΔMs is the torque capacity to be reduced, Ks is the torque adjustment coefficient, T2 is the acceptable engine start time, T2-△t1 represents the lower limit of the start time, T1 is the start time of the current engine start, and t0 is the time unit.

[0038] Figure 4 This is a schematic diagram illustrating the start-up time of the engine start-up process in a hybrid electric vehicle with a P2 module, as described in related technologies. Figure 4 As shown, the threshold torque capacity is T0 and the threshold speed is N0. Curves L1, L2, and L3 correspond to the three engine start-up curves, respectively. The start-up times T1, T2, and T3 for curves L1, L2, and L3 are the time intervals from when the clutch torque capacity reaches the threshold torque capacity T0 until the engine speed reaches the threshold speed N0. Start-up time T1 is less than start-up time T2, and start-up time T2 is less than start-up time T3. Start-up time T2 is the acceptable engine start-up time, with an upper limit of T2 + Δt2 and a lower limit of T2 - Δt1. Therefore, when the start-up time is greater than the lower limit T2 - Δt1 and less than the upper limit T2 + Δt2, there is no need to adjust the clutch torque capacity adaptation for this engine start.

[0039] Figure 5 This is a schematic diagram illustrating the changes in clutch torque capacity adaptation involved in the self-learning process in related technologies, such as... Figure 5 As shown, if the above self-learning strategy is adopted, the clutch torque capacity calculated by the self-learning will fluctuate, and its stability may be poor. Specifically, if the above self-learning strategy is adopted, then... Figure 5As shown, when the engine start time is close to the acceptable engine start time T2, due to some unforeseen factors such as fluctuations in engine operating temperature, the start time may be slightly longer or shorter than T2. ​​In this case, according to the self-learning strategy described above, it is still necessary to decrease or increase the clutch torque capacity adaptation amount. This causes the clutch torque capacity adaptation amount ΔM' to be used for the next engine start to change frequently, resulting in unstable start torque and poor robustness of the self-learning strategy. Furthermore, because the clutch torque capacity adaptation amount ΔM' to be used for the next engine start changes frequently, the data in the storage device used to store ΔM', such as EEPROM, changes frequently, increasing the number of write / erase cycles of the storage device and shortening its lifespan. Moreover, since the determination of the clutch torque capacity adaptation amount ΔM' to be used for the next engine start does not consider the unforeseen factor of engine operating temperature, the determined clutch torque capacity adaptation amount ΔM' may not be a suitable clutch torque capacity compensation value. An unsuitable ΔM' can lead to vehicle driving performance problems, such as short or excessively long engine start times.

[0040] To this end, this application proposes an engine start control method and apparatus for a hybrid electric vehicle. After the engine starts, it is determined whether the start time data of the engine in this start meets a predetermined condition. If the start time data meets the predetermined condition, a first coefficient corresponding to the operating temperature of the engine at the time of this start is calculated based on the start time data. Based on the first coefficient, it is determined whether the clutch torque capacity adaptation amount for the engine corresponding to the operating temperature needs to be adjusted. If it is determined that the clutch torque capacity adaptation amount needs to be adjusted, the clutch torque capacity adaptation amount corresponding to the operating temperature is adjusted based on the first coefficient and a predetermined compensation amount, and the adjusted clutch torque capacity adaptation amount and the operating temperature are stored accordingly. The adjusted clutch torque capacity adaptation amount is used for the next start of the engine corresponding to the operating temperature.

[0041] Therefore, on the one hand, frequent adjustments to the clutch torque capacity adaptation can be avoided, which not only effectively prevents unstable starting torque caused by frequent adjustments, but also effectively prevents frequent changes in the data stored in the storage device. This not only enhances the robustness of the clutch torque capacity adaptation adjustment, but also reduces the number of times the storage device needs to be erased and rewritten, thereby extending the life of the storage device. On the other hand, since the engine operating temperature is considered in the process of determining the clutch torque capacity adaptation, the clutch torque capacity adaptation can converge at different operating temperatures, eliminating the influence of engine operating temperature on the clutch torque capacity adaptation, thereby improving the vehicle's driving performance.

[0042] It should be noted that the engine operating temperature in this application refers to the engine operating at that temperature, i.e., the engine's ambient operating temperature.

[0043] To better understand this application, the following is combined with Figure 6 The flowchart shown will be used to explain this in detail.

[0044] Figure 6 This is a flowchart illustrating an engine start-up control method for a hybrid electric vehicle according to an exemplary embodiment. The hybrid electric vehicle can be an HEV or a PHEV, and the powertrain structure of the hybrid electric vehicle can adopt... Figure 1 The structure shown specifically includes an engine, a drive motor, and a clutch disposed between the engine and the drive motor. This control method can be applied to the hybrid control unit (HCU) of the hybrid vehicle. In other words, the HCU can use the control method described in this embodiment to implement engine start control of the hybrid vehicle.

[0045] It should be understandable. Figure 6 This describes the process of self-learning the clutch torque capacity adaptation. This is executed each time the engine completes its current start at the current temperature. Figure 6 The method shown is used to determine the appropriate clutch torque capacity ΔM to be used during the next start-up of the engine at different operating temperatures. For example... Figure 6 As shown, the control method may include the following steps.

[0046] In step S610, after the engine starts, it is determined whether the engine start-up time data meets predetermined conditions. Step S610 corresponds to the first determination step.

[0047] In this embodiment, after the engine starts, startup time data that can characterize whether the clutch torque capacity adaptation used in the engine startup is appropriate can be obtained. The startup time data may include, but is not limited to, the engine startup time in this startup and time data related to the engine startup time in this startup.

[0048] The startup time data meeting the predetermined conditions may include, but is not limited to, the startup time data falling outside the acceptable startup time data range. That is, if the startup time data is greater than the upper limit of the startup time data range, or if the startup time data is less than the lower limit of the startup time data range, the startup time data meets the predetermined conditions. In step S610, it is determined to be "yes", and the following step S620 is executed.

[0049] Conversely, if the startup time data is not less than the lower limit of the startup time data range and not greater than the upper limit of the startup time data range, the startup time data does not meet the predetermined condition, and the determination in step S610 is "no", and the following step S650 is executed.

[0050] It should be understood that the clutch torque capacity adaptation amount ΔM used during the first start of the engine at different operating temperatures is 0, that is, the initial value of the clutch torque capacity adaptation amount is 0. The method of this embodiment can be used to determine the clutch torque capacity adaptation amount used for non-first start of the engine at different operating temperatures.

[0051] In step S620, a first coefficient corresponding to the operating temperature of the engine at the time of this start-up is calculated based on the start-up time data. Step S620 corresponds to the first calculation step.

[0052] In this embodiment, a first coefficient can be calculated using any suitable algorithm based on the above-mentioned start-up time data to characterize the urgency of self-learning for the clutch torque capacity adaptation of the engine to the operating temperature, so that in the following step S630, it can be determined whether self-learning for the clutch torque capacity adaptation of the engine to the operating temperature is required based on the calculated first coefficient.

[0053] In step S630, it is determined whether the clutch torque capacity adaptation amount corresponding to the engine and the operating temperature needs to be adjusted based on the first coefficient. Step S630 corresponds to the second determination step.

[0054] In this embodiment, if the first coefficient calculated in step S620 represents the urgency of self-learning of the clutch torque capacity adaptation amount corresponding to the engine and the operating temperature, for example, if the first coefficient falls outside the coefficient range, it indicates that self-learning of the clutch torque capacity adaptation amount corresponding to the engine and the operating temperature is required, that is, the clutch torque capacity adaptation amount needs to be adjusted. In other words, if the determination in step S630 is "yes", the following step S640 is executed.

[0055] If the first coefficient calculated in step S620 indicates a low urgency for self-learning of the clutch torque capacity adaptation amount corresponding to the engine and the operating temperature, for example, if the first coefficient falls within the coefficient range, then it means that there is no need to perform self-learning of the clutch torque capacity adaptation amount corresponding to the engine and the operating temperature, that is, there is no need to adjust the clutch torque capacity adaptation amount. In other words, if the determination in step S630 is "no", then the following step S650 is executed.

[0056] In step S640, the clutch torque capacity adaptation amount corresponding to the operating temperature is adjusted according to the first coefficient and the predetermined compensation amount, and the adjusted clutch torque capacity adaptation amount and the operating temperature are stored accordingly. The adjusted clutch torque capacity adaptation amount is used for the next engine start corresponding to the operating temperature. Step S640 corresponds to the adjustment step.

[0057] In this embodiment, after the engine starts, the clutch torque capacity adaptation amount corresponding to the engine's operating temperature at the time of the start can be adjusted according to a first coefficient calculated based on the start time data and a predetermined compensation amount. The operating temperature and the corresponding adjusted clutch torque capacity adaptation amount are stored, and the adjusted clutch torque capacity adaptation amount is used as the clutch torque capacity adaptation amount to be used in the next start of the engine corresponding to the operating temperature.

[0058] The predetermined compensation amount can be a preset value, such as a value pre-calibrated by an engineer. For example, the predetermined compensation amount can generally be 3-5 Nm. Of course, it should be understood that the predetermined compensation amount can also be a value calculated by combining engine historical start-up data and using a corresponding algorithm. This embodiment does not specifically limit the setting method and specific value of the predetermined compensation amount. Based on this embodiment, those skilled in the art can adopt any other suitable method and any suitable value as the predetermined compensation amount according to actual application needs.

[0059] In one possible implementation, the clutch torque capacity adaptation amount for the next start of the engine corresponding to the operating temperature can be adjusted according to a first coefficient and a predetermined compensation amount by: obtaining a correspondence table between the first coefficient and the adjustment direction (decrease / increase), finding the adjustment direction corresponding to the start time data in the correspondence table, and adjusting the clutch torque capacity adaptation amount for the engine corresponding to the operating temperature according to the found adjustment direction and the predetermined compensation amount.

[0060] In one possible implementation, the clutch torque capacity adaptation amount for the next start of the engine corresponding to the operating temperature can also be adjusted according to a first coefficient and a predetermined compensation amount by: obtaining a correspondence table between the first coefficient and the algorithm for adjusting the aforementioned clutch torque capacity adaptation amount; finding the algorithm corresponding to the first coefficient in the correspondence table; calculating the adjustment amount for adjusting the aforementioned clutch torque capacity adaptation amount according to the predetermined compensation amount and using the found algorithm; and using the adjustment amount to adjust the aforementioned clutch torque capacity adaptation amount.

[0061] In step S650, the clutch torque capacity adaptation amount for the engine and the operating temperature is stored.

[0062] Since the engine's operating temperature is not constant during each start-up, when the number of starts completed at different operating temperatures exceeds the preset number, the multiple operating temperatures of the engine can form an operating temperature array. Since each different operating temperature corresponds to a stored clutch torque capacity adaptation value, a clutch torque capacity array is set up corresponding to the operating temperature array, and the values ​​in the clutch torque capacity array correspond one-to-one with the values ​​in the operating temperature array.

[0063] In this embodiment, before starting the engine at the target temperature, the clutch torque capacity corresponding to the target temperature is determined from the clutch torque capacity array for starting the engine at that target temperature, and the above-mentioned... Figure 6 The engine start control method shown determines whether it is necessary to adjust the clutch torque capacity adaptation amount for the engine corresponding to the target temperature. If it is necessary to adjust the clutch torque capacity adaptation amount for the engine corresponding to the target temperature, the clutch torque capacity corresponding to the target temperature is adjusted to the updated clutch torque capacity. If it is not necessary to adjust the clutch torque capacity adaptation amount for the engine corresponding to the target temperature, the clutch torque capacity adaptation amount corresponding to the target temperature is kept unchanged.

[0064] In this embodiment, if the clutch torque capacity adaptation value used in this start-up at the current temperature does not need to be adjusted, the clutch torque capacity adaptation value used in this start-up can be directly stored as the clutch torque capacity adaptation value to be used in the next start-up corresponding to the operating temperature.

[0065] The hybrid vehicle engine start-up control method of this embodiment, after completing the engine start-up, determines whether the start-up time data of the engine in this start-up meets a predetermined condition. If the start-up time data meets the predetermined condition, a first coefficient corresponding to the operating temperature of the engine at the time of start-up is calculated based on the start-up time data. The method then determines whether the clutch torque capacity adaptation amount corresponding to the engine and the operating temperature needs adjustment based on the first coefficient. If the clutch torque capacity adaptation amount needs adjustment, the clutch torque capacity adaptation amount corresponding to the operating temperature is adjusted based on the first coefficient and a predetermined compensation amount, and the adjusted clutch torque capacity adaptation amount and the operating temperature are stored accordingly. This avoids frequent adjustments to the clutch torque capacity adaptation amount, effectively preventing unstable starting torque caused by frequent adjustments, and thus enhancing the robustness of the clutch torque capacity adaptation amount adjustment. Furthermore, since frequent adjustments to the clutch torque capacity adaptation amount are avoided, frequent changes to the data in the storage device caused by frequent adjustments are effectively prevented, thereby reducing the number of write cycles to the storage device and extending its lifespan.

[0066] On the other hand, since the engine operating temperature is taken into account during the determination of the clutch torque capacity adaptation, the clutch torque capacity adaptation can converge under different operating temperatures, eliminating the influence of operating temperature on the clutch torque capacity adaptation, thereby improving the vehicle's driving performance.

[0067] Figure 7 This is a schematic diagram illustrating the convergence of the clutch torque capacity adaptation amount under different temperatures during the self-learning process of the engine start-up control method after applying this embodiment and related technologies. Figure 7 As shown, when the engine is running at different operating temperatures, the clutch torque capacity adaptation involved in the engine start-up process is not constant. The engine's operating temperature directly affects the magnitude of the clutch torque capacity adaptation. For example, at... Figure 7In this embodiment, when the engine operates at a temperature of approximately D1, the corresponding clutch torque capacity adaptation is ΔM1; when the engine operates at a temperature of approximately D3, the corresponding clutch torque capacity adaptation is ΔM3. For some vehicles, the difference between ΔM1 and ΔM3 is too large to be ignored. Compared to using a self-learning strategy in the prior art to adjust the clutch torque capacity adaptation used in this engine start-up, the self-learning strategy of this embodiment allows the clutch torque capacity adaptation to converge at different operating temperatures. By considering the engine's operating temperature, a more reasonable and appropriate clutch torque capacity adaptation is determined, thereby improving driving performance.

[0068] In one possible implementation, the start-up time data may include: the start-up time during the current start-up of the engine, from when the torque capacity of the clutch reaches a threshold torque capacity to when the engine speed reaches a threshold speed, wherein if the start-up time is greater than the upper limit of the start-up time or if the start-up time is less than the lower limit of the start-up time, the first determination step determines that the start-up time data meets the predetermined condition.

[0069] In this embodiment, the engine start-up time data during the current start-up at the current temperature may include the engine start-up time during this start-up. This start-up time represents the time from when the clutch torque capacity reaches the threshold torque capacity to when the engine speed reaches the threshold speed during the current engine start-up period. Accordingly, if the start-up time is greater than the upper limit of the start-up time or less than the lower limit of the start-up time, it is determined as "yes" in step S610; conversely, if the start-up time is not less than the lower limit of the start-up time and not greater than the upper limit of the start-up time, it is determined as "no" in step S610.

[0070] Since engines typically operate within a certain temperature range, their operating temperatures are discrete. With frequent engine starts, the corresponding operating temperature values ​​are also numerous. To conserve storage capacity, this application pre-defines an operating temperature array corresponding to the engine's operating temperature. This array contains pre-defined discrete temperature values, including n preset temperature values ​​(n being a positive integer greater than 2). The minimum and maximum values ​​in this array correspond to the critical operating temperature values ​​of the engine. The temperature values ​​in this array can be arranged in ascending or descending order, and any suitable algorithm can be used to determine the first temperature corresponding to the operating temperature from this array.

[0071] In a possible implementation, step S620 may include: calculating a first temperature corresponding to the working temperature in a pre-set working temperature array; calculating a coefficient corresponding to the first temperature based on the start time data and an acceptable engine start time as the first coefficient.

[0072] Since the first temperature is derived from a pre-set working temperature array and the first coefficient exists corresponding to the first temperature, a first coefficient array is set corresponding to the working temperature array, and the values in the first coefficient array correspond one by one to the values in the working temperature array.

[0073] In this embodiment, the first temperature corresponding to the working temperature in the working temperature array can be obtained by comparing the mean value of two adjacent temperature values in the working temperature array with the working temperature.

[0074] In a possible implementation, if the working temperature at the current start is the same as a pre-set temperature value in the working temperature array, then directly determine this pre-set temperature value (i.e., the working temperature) as the first temperature.

[0075] In a possible implementation, if the working temperature at the current start is less than the mean value of the two smallest temperature values in the working temperature array, then determine the first temperature corresponding to the working temperature as the smallest temperature value in the working temperature array; if the working temperature is greater than the mean value of the two largest temperature values in the working temperature array, then determine the first temperature corresponding to the working temperature as the largest temperature value in the working temperature array; if the working temperature is greater than the mean value of the i-th temperature value and the adjacent (i - 1)-th temperature value before it in the working temperature array and less than the mean value of the i-th temperature value and the adjacent (i + 1)-th temperature value after it, then determine the first temperature as the i-th temperature value.

[0076] For example, if the working temperature array is represented by D[D1, D2, …… Dn], and the temperature values in the working temperature array are arranged in ascending order, and the working temperature at the current start is represented by Dx: if Dx < (D1 + D2) / 2, then x = 1, indicating that the first temperature corresponding to the working temperature in the working temperature array is D1; if Dx > (Dn - 1 + Dn) / 2, then x = n, indicating that the first temperature corresponding to the working temperature in the working temperature array is Dn; if (Di - 1 + Di) / 2 < Dx <= (Di + D(i + 1)) / 2, then x = i, where i is an integer value greater than 1 and less than n, indicating that the first temperature corresponding to the working temperature in the working temperature array is Di.

[0077] In a possible implementation, if the working temperature at this startup is less than the average value of the minimum temperature value in the working temperature array, then the first temperature corresponding to the working temperature is determined as the minimum temperature value in the working temperature array; if the working temperature is greater than the maximum temperature value in the working temperature array, then the first temperature corresponding to the working temperature is determined as the maximum temperature value in the working temperature array; if the working temperature is greater than the i-th temperature value in the working temperature array and less than the adjacent (i + 1)-th temperature value after that, then the first temperature is determined as the i-th temperature value.

[0078] For example, the working temperature array is represented by D[D1, D2, …… Dn]. If the temperature values in the working temperature array are arranged in ascending order, and the working temperature at this startup is represented by Dx: If Dx < D1, then x = 1, indicating that the first temperature corresponding to the working temperature in the working temperature array is D1; if Dx > Dn, then x = n, indicating that the first temperature corresponding to the working temperature in the working temperature array is Dn; if Di < Dx <= D(i + 1), then x = i, where i is an integer greater than 1 and less than n, indicating that the first temperature corresponding to the working temperature in the working temperature array is Di.

[0079] In the above implementation, exemplarily, the temperature values in the working temperature array are arranged in ascending order. Of course, when the temperature values in the working temperature array are arranged in descending order, when determining the first temperature, just interchange the greater and less in the logical judgment directly.

[0080] It is worth mentioning that the above implementation of determining the first temperature corresponding to the working temperature at this startup in the working temperature array is only for exemplary illustration. The first temperature matching the working temperature can be determined by using relevant algorithms based on the working temperature and the temperature values in the working temperature array. For example, the temperature value with the smallest difference from the working temperature in the working temperature array is determined as the first temperature. The present application does not make specific limitations on this, as long as the first temperature matching the working temperature can be determined.

[0081] In this embodiment, the first coefficient corresponding to the first temperature can be calculated by using relevant algorithms based on the above startup time data and the acceptable engine startup time.

[0082] It should be noted that since each temperature value in the working temperature array corresponds to a first coefficient, in this embodiment, a first coefficient array is set corresponding to the working temperature array, and the values of the first coefficient array correspond one by one to the values in the working temperature array.

[0083] In one possible implementation, the first coefficient Kx corresponding to the first temperature can be calculated using the formula Kx = Kx' + Gu + Gd. If the engine starts for too long during this start-up (e.g., the start-up time is greater than the upper limit of the start-up time), Gu can be calculated using the formula Gu = Rond((T3-(T2+△t2)) / t0); if the engine starts for too short a time during this start-up (e.g., the start-up time is less than the lower limit of the start-up time), Gd can be calculated using the formula Gd = Rond((T1-(T2-△t1)) / t0).

[0084] Where Kx' is the x-th first coefficient Kx in the first coefficient array, which is the first coefficient corresponding to the first temperature determined in the previous start-up, T2 is the acceptable engine start-up time, T2+△t2 represents the upper limit of the start-up time, T3 is the start-up time of the engine in this start-up, t0 is the time unit, T2-△t1 represents the lower limit of the start-up time, T1 is the start-up time of the engine in this start-up, Rond() is the floor function, Gu is a positive integer, and Gd is a negative integer.

[0085] In one possible implementation, step S630 includes: determining whether the first coefficient is greater than the upper limit of the first coefficient or less than the lower limit of the first coefficient; if the first coefficient is greater than the upper limit of the first coefficient or less than the lower limit of the first coefficient, determining that it is necessary to adjust the clutch torque capacity adaptation amount for the engine corresponding to the operating temperature at the time of startup.

[0086] In this embodiment, if the first coefficient is greater than the upper limit or less than the lower limit, then the first coefficient indicates a high urgency for self-learning of the clutch torque capacity adaptation between the engine and the operating temperature, requiring self-learning of the clutch torque capacity adaptation between the engine and the operating temperature. Step S630 determines this as "Yes". Otherwise, if the first coefficient is not less than the lower limit and not greater than the upper limit, then the first coefficient indicates a low urgency for self-learning of the clutch torque capacity adaptation between the engine and the operating temperature, requiring no self-learning of the clutch torque capacity adaptation between the engine and the operating temperature. Step S630 determines this as "No".

[0087] In one possible implementation, step S640 may include: determining the torque adjustment direction based on the first coefficient; and adjusting the predetermined compensation amount by the clutch torque capacity adaptation amount corresponding to the operating temperature according to the torque adjustment direction.

[0088] In this embodiment, if the first coefficient Kx is greater than the upper limit value Ku of the first coefficient, it indicates that the start-up time is too long and the target clutch torque capacity transmitted by the clutch is too small. Therefore, it is necessary to increase the clutch torque capacity adaptation amount corresponding to the operating temperature during the current start-up of the engine. Thus, the torque adjustment direction is determined to be upward, and a predetermined compensation amount is added to the clutch torque capacity adaptation amount corresponding to the operating temperature of the engine, that is, ΔMx'=ΔMx+ΔM0, where ΔMx' represents the adjusted clutch torque capacity adaptation amount, ΔMx represents the clutch torque capacity adaptation amount corresponding to the operating temperature of the engine, ΔM0 represents the predetermined compensation amount, which can be calibrated by the engineer, and Ku represents the upper limit value of the first coefficient, which can be calibrated by the engineer.

[0089] If the first coefficient Kx is less than the lower limit of the first coefficient Kd, it indicates that the starting time is too short and the target clutch torque capacity transmitted by the clutch is too large. Therefore, it is necessary to reduce the clutch torque capacity adaptation amount corresponding to the first temperature during the engine's current start-up. Thus, the torque adjustment direction is determined to be downward, and the clutch torque capacity adaptation amount used for the engine corresponding to the operating temperature is reduced by a predetermined compensation amount, that is, ΔMx'=ΔMx-ΔM0, where ΔMx' represents the adjusted clutch torque capacity adaptation amount, ΔMx represents the clutch torque capacity adaptation amount used for the engine corresponding to the operating temperature, ΔM0 represents the predetermined compensation amount, which can be calibrated by the engineer, and Kd represents the lower limit of the first coefficient, which can be calibrated by the engineer.

[0090] It should be noted that after adjusting the clutch torque capacity adaptation, the first coefficient Kx needs to be initialized to 0. If it is determined that no adjustment of the clutch torque capacity adaptation is needed, the first coefficient Kx should be kept at its previously calculated value. That is, in each engine start, the first coefficient Kx is only calculated if it is determined in step S610 that it needs to be calculated (i.e., the start time data in this start meets predetermined conditions), and the initial value of the first coefficient Kx is always 0.

[0091] The following description serves as a specific example of the self-learning strategy in this embodiment.

[0092] The operating temperature array D[D1, D2, ..., Dn], the first coefficient array K[K1, K2, ..., Kn] involved in the self-learning strategy, and the clutch torque capacity adaptation array M[ΔM1, ΔM2, ..., ΔMn] involved in the self-learning strategy are all in one-to-one correspondence.

[0093] Calculate intermediate variables Gu and Gd. Specifically, if the startup time of the engine in the current startup at the operating temperature Dx is greater than the upper limit value of the startup time, use the formula Gu = Rond((T3 - (T2 + Δt2)) / t0) to calculate Gu; if the startup time of the engine in the current startup at the operating temperature Dx is less than the lower limit value of the startup time, use the formula Gd = Rond((T1 - (T2 - Δt1)) / t0) to calculate Gd.

[0094] If the self-learning process is activated, that is, if the startup time of the engine in the current startup at the operating temperature Dx is greater than the upper limit value of the startup time or less than the lower limit value of the startup time, determine the first temperature corresponding to the operating temperature Dx in the operating temperature array.

[0095] As Figure 8 shown, Figure 8 is an exemplary schematic diagram of the operating temperature DX, where the operating temperature DX satisfies: (D1 + D2) / 2 < Dx <= (D2 + D3) / 2, so the value of x is 2. Use the formula K2 = K2' + Gu + Gd to calculate the first coefficient K2 corresponding to the first temperature, where K2' is the first coefficient K2 corresponding to the D2 temperature after the previous startup.

[0096] If the first coefficient K2 > the upper limit value Ku of the first coefficient, use the formula ΔM2 = ΔM2' + ΔM0 to calculate the adjusted clutch torque capacity adaptation amount and store it. At the same time, clear the first coefficient K2; if the first coefficient K2 < the lower limit value Kd of the first coefficient, use the formula ΔM2 = ΔM2' - ΔM0 to calculate the adjusted clutch torque capacity adaptation amount and store it. At the same time, clear the first coefficient K2; if the lower limit value Kd of the first coefficient <= the first coefficient K2 <= the upper limit value Ku of the first coefficient, do not adjust the clutch torque capacity adaptation amount and keep the first coefficient K2 unchanged, which is the K2 value calculated after the current startup.

[0097] Exemplarily, since the engine has been started at countless different operating temperatures, the clutch torque capacity adaptation amount array M has become an adjusted array, and the clutch torque capacity adaptation amount △M for the next startup of the engine can be determined according to the clutch torque capacity adaptation amount array △M.

[0098] In a possible implementation manner, the above engine startup control method further includes:

[0099] Before the next start-up period corresponding to the target temperature of the engine, calculate the target clutch torque capacity adaptation amount for the target temperature according to the corresponding relationship between the stored clutch torque capacity adaptation amount array and the working temperature array, and calculate the target clutch torque capacity when starting to supply fuel to the engine according to the clutch basic torque capacity and the target clutch torque capacity adaptation amount;

[0100] During the next start-up period of the engine corresponding to the target temperature, when the torque capacity of the clutch reaches the target clutch torque capacity and the rotational speed of the engine reaches a predetermined rotational speed, start to supply fuel to the engine.

[0101] Specifically, as Figure 9 shown, Figure 9 is a schematic diagram for calculating the clutch torque capacity adaptation amount △M. If the target temperature for the next start-up of the engine is Dy, the target clutch torque capacity adaptation amount △M for the engine at temperature Dy is determined by the following method: If Dy < D1 and y = 1, then △M = △M1; if Dy > Dn and y = n, then △M = △Mn; if Di < Dy <= D(i + 1) and y = i, where i is an integer value greater than 1 and less than n, then △M = (Dy - Di) / (D(i + 1) - Di) * △M(i + 1) + (D(i + 1) - Dy) / (D(i + 1) - Di) * △Mi.

[0102] Therefore, introduce intermediate variables Gu and Gd calculated based on the start-up time data in the current start-up of the engine and the acceptable start-up time data to calculate the urgency degree characterizing the need for self-learning in the current start-up of the engine. Only when the cumulative self-learning urgency degree K reaches above the upper limit value Ku or below the lower limit value Kd, adjust the clutch torque capacity adaptation amount corresponding to the working temperature of the engine in the current start-up. Specifically, as Figure 8 shown, compared with the curve of the clutch torque capacity adaptation amount ΔM in the prior art that fluctuates frequently, the curve of the clutch torque capacity adaptation amount ΔM in this embodiment does not fluctuate. More importantly, through the above self-learning strategy, the clutch torque capacity adaptation amount ΔM converges at different working temperatures, eliminating the influence of the engine's working temperature on the clutch torque capacity adaptation amount ΔM and improving the driving performance of the vehicle.

[0103] In this embodiment, the clutch basic torque capacity is introduced when calculating the target clutch torque capacity when supplying fuel to the engine. The target clutch torque capacity when starting to supply fuel to the engine in the next start-up of the engine can be calculated by using corresponding algorithms including but not limited to addition according to the clutch basic torque capacity and the target clutch torque capacity adaptation amount.

[0104] In one possible implementation, the basic torque capacity of the clutch can be determined based on the engine's resistance torque. Specifically, the basic torque capacity of the clutch can be determined by: obtaining relevant information affecting the engine's resistance torque, including the engine's coolant temperature; determining the engine's resistance torque based on this relevant information; and determining the basic torque capacity of the clutch based on the determined resistance torque.

[0105] Since information including, but not limited to, engine coolant temperature affects the engine's drag torque—for example, the lower the coolant temperature, the greater the engine's drag torque—the engine's drag torque can be determined based on this information, and then the basic clutch torque capacity can be determined based on the determined drag torque. In one possible implementation, a coolant temperature sensor can be used to detect the coolant temperature, and the coolant temperature detected by the sensor can be acquired.

[0106] During the next engine start-up, it is possible to monitor whether the clutch torque capacity has decreased to the calculated target clutch torque capacity and whether the engine speed has reached a threshold speed; when it is detected that the clutch torque capacity has decreased to the target clutch torque capacity and the engine speed has reached the threshold speed, for example, a command to start supplying fuel to the engine is sent to the fuel feeding device including the fuel tank and the injector; in response to receiving the command, the fuel feeding device begins to supply fuel to the engine.

[0107] The hybrid vehicle engine start-up control method of this embodiment, after each start-up of the engine at different operating temperatures, calculates a first coefficient corresponding to the operating temperature at the time of the start-up if the start-up time data of the engine in this start-up meets predetermined conditions. Based on the first coefficient, it determines whether the clutch torque capacity adaptation amount corresponding to the engine operating temperature needs adjustment. The clutch torque capacity adaptation amount is adjusted only if it is determined that adjustment is needed based on the first coefficient. The adjusted clutch torque capacity adaptation amount and its corresponding operating temperature are stored, forming a clutch torque capacity adaptation amount array and an operating temperature array. During the next start-up of the engine corresponding to the target temperature, the stored clutch torque capacity adaptation amount is used to... The target clutch torque capacity is calculated based on the array and the operating temperature array for the corresponding target temperature. When the clutch torque capacity reaches the calculated target clutch torque capacity and the engine speed reaches the threshold speed, fuel is supplied to the engine. Since the target clutch torque capacity used is calculated based on the adjusted clutch torque capacity adaptation, the target clutch torque capacity used in the next engine start at the target temperature is always reasonable. This ensures that the engine speed can reach the threshold speed in time during the next engine start at the target temperature, thus enabling timely engine start-up. Because the adjusted clutch torque capacity adaptation varies for different engine operating temperatures, the influence of engine operating temperature on the clutch torque capacity adaptation can be eliminated, improving vehicle driving performance.

[0108] Figure 10 This is a block diagram illustrating an engine start control device for a hybrid electric vehicle according to an exemplary embodiment. The hybrid electric vehicle can be an HEV or a PHEV, and the powertrain structure of the hybrid electric vehicle can adopt... Figure 1 The structure shown specifically includes an engine, a drive motor, and a clutch disposed between the engine and the drive motor. This control device 1000 can be applied to the hybrid power control unit (HCU) of a hybrid vehicle. Figure 10 As shown, the control device 1000 may include a first judgment module 1010, a first calculation module 1020, a second judgment module 1030, and an adjustment module 1040.

[0109] The first judgment module 1010 is used to determine whether the start-up time data of the engine in this start-up meets the predetermined conditions after the engine is started. The first calculation module 1020 is connected to the first judgment module 1010 and is used to calculate a first coefficient corresponding to the operating temperature of the engine at the time of this start-up based on the start-up time data if the start-up time data meets the predetermined conditions.

[0110] The second judgment module 1030 is connected to the first calculation module 1020 and is used to determine whether it is necessary to adjust the clutch torque capacity adaptation amount corresponding to the engine and the operating temperature based on the first coefficient. The adjustment module 1040 is connected to the second judgment module 1030 and is used to adjust the clutch torque capacity adaptation amount corresponding to the operating temperature based on the first coefficient and a predetermined compensation amount if it is determined that the clutch torque capacity adaptation amount needs to be adjusted, and to store the adjusted clutch torque capacity adaptation amount and the operating temperature accordingly, wherein the adjusted clutch torque capacity adaptation amount is used for the next start of the engine corresponding to the operating temperature.

[0111] In one possible implementation, the first calculation module 1020 is configured to: calculate a first temperature corresponding to the operating temperature in the pre-set operating temperature array; calculate a coefficient corresponding to the first temperature as the first coefficient based on the start-up time data and an acceptable engine start-up time, wherein the start-up time data includes: the start-up time during the current engine start-up period from when the clutch torque capacity reaches a threshold torque capacity until the engine speed reaches a threshold speed.

[0112] In one possible implementation, the first calculation module 1020 is configured to compare the temperature values ​​in the working temperature array with the working temperature to obtain a first temperature corresponding to the working temperature in the working temperature array.

[0113] In one possible implementation, the start-up time data includes: the start-up time during the current start-up of the engine, from when the torque capacity of the clutch reaches a threshold torque capacity to when the engine speed reaches a threshold speed, wherein if the start-up time is greater than the upper limit of the start-up time or less than the lower limit of the start-up time, the first judgment module determines that the start-up time data meets the predetermined condition.

[0114] In one possible implementation, the second judgment module 1030 is configured to: determine whether the first coefficient is greater than the upper limit of the first coefficient or less than the lower limit of the first coefficient; if the first coefficient is greater than the upper limit of the first coefficient or less than the lower limit of the first coefficient, determine that the clutch torque capacity adaptation amount needs to be adjusted.

[0115] In one possible implementation, the adjustment module 1040 is configured to: determine the torque adjustment direction based on the first coefficient; and adjust the predetermined compensation amount by the clutch torque capacity adaptation amount corresponding to the operating temperature according to the torque adjustment direction.

[0116] In one possible implementation, the adjustment module 1040 is configured to: if the first coefficient is greater than the upper limit of the first coefficient, determine that the torque adjustment direction is upward, and increase the clutch torque capacity adaptation amount corresponding to the operating temperature by the predetermined compensation amount; if the first coefficient is less than the lower limit of the first coefficient, determine that the torque adjustment direction is downward, and decrease the clutch torque capacity adaptation amount corresponding to the operating temperature by the predetermined compensation amount.

[0117] In one possible implementation, the control device 1000 may further include: a second calculation module (not shown), configured to calculate, before the next start-up period corresponding to the target temperature, a target clutch torque capacity adaptation value for the target temperature based on a stored correspondence between a clutch torque capacity adaptation value array and an operating temperature array, and to calculate, based on the basic clutch torque capacity and the target clutch torque capacity adaptation value, a target clutch torque capacity when fuel supply to the engine begins; and a start-up module (not shown), configured to, during the next start-up period corresponding to the target temperature, begin supplying fuel to the engine when the clutch torque capacity reaches the target clutch torque capacity and the engine speed reaches a predetermined speed.

[0118] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0119] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical applications, or technical improvements to the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for controlling the engine start of a hybrid electric vehicle, the hybrid electric vehicle comprising an engine, a drive motor, and a clutch disposed between the engine and the drive motor, characterized in that, The engine start control method includes: The first judgment step is used to determine whether the start-up time data of the engine in this start-up meets the predetermined conditions after the engine is started. The first calculation step is used to calculate a first coefficient corresponding to the operating temperature of the engine at the time of this start-up if it is determined that the start-up time data meets the predetermined conditions. The second judgment step is used to determine, based on the first coefficient, whether it is necessary to adjust the clutch torque capacity adaptation amount corresponding to the engine and the operating temperature; and The adjustment step is used to adjust the clutch torque capacity adaptation amount corresponding to the operating temperature according to the first coefficient and the predetermined compensation amount if it is determined that the clutch torque capacity adaptation amount needs to be adjusted, and to store the adjusted clutch torque capacity adaptation amount and the operating temperature accordingly, wherein the adjusted clutch torque capacity adaptation amount is used for the next start of the engine corresponding to the operating temperature.

2. The engine start control method according to claim 1, characterized in that, The first calculation step includes: Calculate the first temperature corresponding to the operating temperature in the pre-set operating temperature array; The coefficient corresponding to the first temperature is calculated based on the start-up time data and the acceptable engine start-up time as the first coefficient. The start-up time data includes the start-up time during the current engine start-up period, from when the clutch torque capacity reaches the threshold torque capacity to when the engine speed reaches the threshold speed.

3. The engine start control method according to claim 2, characterized in that, The first calculation step includes: The temperature values ​​in the working temperature array are compared with the working temperature to obtain the first temperature corresponding to the working temperature in the working temperature array.

4. The engine start control method according to claim 1, characterized in that, The start-up time data includes: the start-up time during the current engine start-up period, from when the clutch torque capacity reaches the threshold torque capacity until the engine speed reaches the threshold speed. Specifically, if the startup time is greater than the upper limit of the startup time or less than the lower limit of the startup time, the first determination step determines that the startup time data meets the predetermined condition.

5. The engine start control method according to claim 1, characterized in that, The second determination step includes: Determine whether the first coefficient is greater than the upper limit of the first coefficient or less than the lower limit of the first coefficient; If the first coefficient is greater than the upper limit of the first coefficient or less than the lower limit of the first coefficient, it is determined that the clutch torque capacity adaptation amount needs to be adjusted.

6. The engine start control method according to claim 5, characterized in that, The adjustment steps include: The torque adjustment direction is determined based on the first coefficient; According to the torque adjustment direction, the predetermined compensation amount is adjusted to the clutch torque capacity adaptation amount corresponding to the operating temperature.

7. The engine start control method according to claim 6, characterized in that, The adjustment steps include: If the first coefficient is greater than the upper limit of the first coefficient, then the torque adjustment direction is determined to be upward, and the clutch torque capacity adaptation amount corresponding to the working temperature is increased by the predetermined compensation amount. If the first coefficient is less than the lower limit of the first coefficient, then the torque adjustment direction is determined to be downward, and the clutch torque capacity adaptation amount corresponding to the operating temperature is reduced by the predetermined compensation amount.

8. The engine starting control method according to any one of claims 1 to 7, characterized in that, The adjustment steps are followed by: The second calculation step is used to calculate the target clutch torque capacity adaptation for the target temperature based on the correspondence between the stored clutch torque capacity adaptation array and the operating temperature array before the next start-up period corresponding to the engine and the target temperature, and to calculate the target clutch torque capacity when fuel is supplied to the engine at the beginning based on the basic clutch torque capacity and the target clutch torque capacity adaptation. The start-up step is used to begin supplying fuel to the engine when, during the next start-up of the engine corresponding to the target temperature, the torque capacity of the clutch reaches the target clutch torque capacity and the engine speed reaches a predetermined speed.

9. An engine start control device for a hybrid electric vehicle, the hybrid electric vehicle comprising an engine, a drive motor, and a clutch disposed between the engine and the drive motor, characterized in that, The engine start control device includes: The first judgment module is used to determine whether the start-up time data of the engine in this start-up meets the predetermined conditions after the engine is started. The first calculation module is used to calculate a first coefficient corresponding to the operating temperature of the engine at the time of this start-up if it is determined that the start-up time data meets the predetermined conditions. The second judgment module is used to determine, based on the first coefficient, whether it is necessary to adjust the clutch torque capacity adaptation amount corresponding to the engine and the operating temperature; and An adjustment module is used to adjust the clutch torque capacity adaptation amount corresponding to the operating temperature according to the first coefficient and a predetermined compensation amount if it is determined that the clutch torque capacity adaptation amount needs to be adjusted, and to store the adjusted clutch torque capacity adaptation amount and the operating temperature accordingly, wherein the adjusted clutch torque capacity adaptation amount is used for the next start of the engine corresponding to the operating temperature.

10. The engine start control device according to claim 9, characterized in that, The first computing module is configured as follows: Calculate the first temperature corresponding to the operating temperature in the pre-set operating temperature array; The coefficient corresponding to the first temperature is calculated based on the start-up time data and the acceptable engine start-up time as the first coefficient. The start-up time data includes the start-up time during the current engine start-up period, from when the clutch torque capacity reaches the threshold torque capacity to when the engine speed reaches the threshold speed.

11. The engine start control device according to claim 10, characterized in that, The first computing module is configured as follows: The temperature values ​​in the working temperature array are compared with the working temperature to obtain the first temperature corresponding to the working temperature in the working temperature array.

12. The engine start control device according to claim 9, characterized in that, The start-up time data includes: the start-up time during the current engine start-up period, from when the clutch torque capacity reaches the threshold torque capacity until the engine speed reaches the threshold speed. Specifically, if the startup time is greater than the upper limit of the startup time or less than the lower limit of the startup time, the first judgment module determines that the startup time data meets the predetermined condition.

13. The engine start control device according to claim 9, characterized in that, The second judgment module is configured as follows: Determine whether the first coefficient is greater than the upper limit of the first coefficient or less than the lower limit of the first coefficient; If the first coefficient is greater than the upper limit of the first coefficient or less than the lower limit of the first coefficient, it is determined that the clutch torque capacity adaptation amount needs to be adjusted.

14. The engine start control device according to claim 13, characterized in that, The adjustment module is configured as follows: The torque adjustment direction is determined based on the first coefficient; According to the torque adjustment direction, the predetermined compensation amount is adjusted to the clutch torque capacity adaptation amount corresponding to the operating temperature.

15. The engine start control device according to claim 14, characterized in that, The adjustment module is configured as follows: If the first coefficient is greater than the upper limit of the first coefficient, then the torque adjustment direction is determined to be upward, and the clutch torque capacity adaptation amount corresponding to the working temperature is increased by the predetermined compensation amount. If the first coefficient is less than the lower limit of the first coefficient, then the torque adjustment direction is determined to be downward, and the clutch torque capacity adaptation amount corresponding to the operating temperature is reduced by the predetermined compensation amount.

16. The engine start control device according to any one of claims 9 to 15, characterized in that, Also includes: The second calculation module is used to calculate the target clutch torque capacity adaptation for the target temperature according to the correspondence between the stored clutch torque capacity adaptation array and the operating temperature array before the next start-up period corresponding to the engine and the target temperature, and to calculate the target clutch torque capacity when fuel is supplied to the engine at the beginning according to the basic clutch torque capacity and the target clutch torque capacity adaptation. The starting module is configured to, during the next start-up of the engine corresponding to the target temperature, begin supplying fuel to the engine when the torque capacity of the clutch reaches the target clutch torque capacity and the engine speed reaches a predetermined speed.

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