A method and device for controlling engine start of hybrid vehicle

Abstract

The present invention discloses a method and device for controlling the engine start of a hybrid vehicle, the method comprising: when it is determined that the engine of a target vehicle needs to be started, performing a first oil flushing operation on the clutch of the target vehicle, and obtaining the current speed of the target vehicle; determining a target control strategy that matches the current speed from a predetermined control strategy set according to the current speed, and controlling the engine start based on the target control strategy. It can be seen that the implementation of the present invention can obtain the current speed of the target vehicle when it is determined that the engine of the target vehicle needs to be started, and select a control strategy that matches the current speed of the target vehicle, and control the engine start of the vehicle according to the control strategy, so that the driving smoothness of the car driver can be ensured during the process of starting the engine of the vehicle, and the torque impact caused to the vehicle by the engine during the starting process can be reduced and the engine start time can be shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control, and in particular to an engine start control method and device for a hybrid electric vehicle. Background Art

[0002] With the development of science and technology, the progress of society, and the strengthening of people's environmental awareness, the new energy vehicle (e.g. hybrid vehicle) industry has developed rapidly. The rapid development of new energy vehicles has greatly reduced the use of fuel (e.g. gasoline, diesel) vehicles, thereby reducing exhaust emissions and environmental pollution, which is beneficial to environmental protection.

[0003] In practice, it is found that hybrid vehicles have many advantages, one of which is that the best power source can be selected to participate in the vehicle driving process according to the vehicle driving conditions. When the vehicle has sufficient power or the real-time driving torque requirement is low, the pure electric mode can be selected to drive the vehicle; when the vehicle has low power or the driver's real-time torque requirement is large, the hybrid mode can be selected to drive the vehicle. Therefore, hybrid vehicles inevitably need to start the engine while driving. In the process of starting the engine, the dragging and pulling of the engine speed and the sudden change of the output torque during the engine starting process may be transmitted to the wheel end, which has a greater impact on the driving smoothness. Therefore, in the process of starting the engine, how to ensure the driving smoothness of the car driver has always been a difficult problem to be solved in the control process of hybrid vehicles. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an engine start control method and device for a hybrid vehicle, which can ensure the driving smoothness of the vehicle driver during the process of starting the engine by selecting a control strategy that matches the current speed of the vehicle and controlling the engine start of the vehicle according to the control strategy.

[0005] In order to solve the above technical problems, a first aspect of an embodiment of the present invention discloses a method for controlling engine start of a hybrid vehicle, the method comprising:

[0006] When it is determined that the engine of the target vehicle needs to be started, a first oil flushing operation is performed on the clutch of the target vehicle, and a current vehicle speed of the target vehicle is acquired;

[0007] A target control strategy matching the current vehicle speed is determined from a predetermined control strategy set according to the current vehicle speed, and the engine start is controlled based on the target control strategy.

[0008] It can be seen that the first aspect of the present invention can obtain the current speed of the target vehicle when it is determined that the engine of the target vehicle needs to be started, select a control strategy that matches the current speed of the target vehicle, and control the engine start of the vehicle according to the control strategy. In the process of starting the engine of the vehicle, the driving smoothness of the car driver can be ensured, the torque impact caused to the vehicle by the engine during the starting process can be reduced, and the driving safety of the driver can be improved. By controlling the engine start through a control strategy that matches the vehicle speed, the engine start time can also be shortened.

[0009] A second aspect of an embodiment of the present invention discloses an engine start control device for a hybrid vehicle, the device comprising a fuel charging module, an acquisition module, a first determination module and a first control module, wherein:

[0010] The oil flushing module is used to perform an oil flushing operation on the clutch of the target vehicle when it is determined that the engine of the target vehicle needs to be started;

[0011] The acquisition module is used to acquire the current speed of the target vehicle;

[0012] The first determination module is used to determine a target control strategy matching the current vehicle speed from a predetermined control strategy set according to the current vehicle speed;

[0013] The first control module is used to control the engine start-up based on the target control strategy.

[0014] It can be seen that the second aspect of the present invention can obtain the current speed of the target vehicle when it is determined that the engine of the target vehicle needs to be started, select a control strategy that matches the current speed of the target vehicle, and control the engine start of the vehicle according to the control strategy. In the process of starting the engine of the vehicle, the driving smoothness of the car driver can be ensured, and the torque impact caused to the vehicle by the engine during the starting process can be reduced and the starting time of the engine can be shortened.

[0015] The third aspect of the present invention discloses another hybrid vehicle engine start control device, the device comprising:

[0016] A memory storing executable program code;

[0017] a processor coupled to the memory;

[0018] The processor calls the executable program code stored in the memory to execute the engine start control method for the hybrid vehicle disclosed in the first aspect of the present invention.

[0019] The third aspect of the present invention discloses a computer storable medium, wherein the computer storage medium stores computer instructions, and when the computer instructions are called, they are used to execute the engine start control method for a hybrid vehicle disclosed in the first aspect of the present invention.

[0020] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0021] In an embodiment of the present invention, a method and device for controlling engine start of a hybrid vehicle are disclosed. The method can obtain the current speed of a target vehicle when determining that the engine of the target vehicle needs to be started, select a control strategy that matches the current speed of the target vehicle, and control the engine start of the vehicle according to the control strategy. In the process of starting the engine of the vehicle, the driving smoothness of the driver can be ensured, the torque impact caused by the engine to the vehicle during the starting process can be reduced, and the driving safety of the driver can be improved. The engine start can be controlled by a control strategy that matches the vehicle speed, and the engine start time can be shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 It is a flow chart of an engine start control method for a hybrid vehicle disclosed in an embodiment of the present invention;

[0024] Figure 2 It is a flow chart of another hybrid vehicle engine start control method disclosed in an embodiment of the present invention;

[0025] Figure 3 It is a flow chart of another hybrid vehicle engine start control method disclosed in an embodiment of the present invention;

[0026] Figure 4 It is a structural schematic diagram of an engine start control device for a hybrid vehicle disclosed in an embodiment of the present invention;

[0027] Figure 5 It is a structural schematic diagram of another hybrid vehicle engine start control device disclosed in an embodiment of the present invention;

[0028] Figure 6 is a structural schematic diagram of a second judgment submodule disclosed in an embodiment of the present invention;

[0029] Figure 7 is a structural schematic diagram of a second judgment submodule disclosed in an embodiment of the present invention;

[0030] Figure 8 It is a structural schematic diagram of another hybrid vehicle engine start control device disclosed in an embodiment of the present invention;

[0031] Fig. 9 It is a structural schematic diagram of another hybrid vehicle engine start control device disclosed in an embodiment of the present invention;

[0032] Fig.10 It is a structural schematic diagram of another hybrid vehicle engine start control device disclosed in an embodiment of the present invention;

[0033] Fig.11 It is a simplified structural diagram of a whole vehicle power system corresponding to an engine starting control method of a hybrid vehicle disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, device, product or equipment that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or equipment.

[0036] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0037] The present invention discloses a hybrid vehicle engine start control method and device, which can obtain the current speed of the target vehicle when determining that the target vehicle's engine needs to be started, select a control strategy that matches the current speed of the target vehicle, and control the vehicle engine start according to the control strategy. In the process of starting the vehicle engine, the driving comfort of the driver can be guaranteed, and the torque impact caused by the engine to the vehicle during the starting process can be reduced, thereby improving the driver's driving safety. The engine start can be controlled by a control strategy that matches the vehicle speed, and the engine start time can also be shortened. The following are detailed descriptions.

[0038] Fig.11 It is a simplified structural diagram of the vehicle power system, such as Fig.11 As shown, one end of the engine 1 is connected to the active plate a of the clutch (C0 clutch) 2, the driven plate b of the clutch 2 is connected to the generator 3 through the ring gear c of the planetary gear mechanism, the ring gear c is connected to the wheel end 4 through the planet carrier d, and the wheel end 4 is connected to the drive motor 5 through the gear e, wherein the clutch 2 and the generator 3 transmit the torque to the wheel end 4 through the ring gear c and the planet carrier d, and the drive motor 5 transmits the torque to the wheel end 4 through the gear e, thereby starting the engine 1. For the specific method of starting the engine based on the clutch slip friction of the vehicle power system, please refer to the specific description in the first to third embodiments.

[0039] Embodiment 1

[0040] See also Figure 1 , Figure 1 1 is a flow chart of a method for controlling the engine start of a hybrid vehicle disclosed in an embodiment of the present invention. The method is applied to a vehicle control terminal (also known as a vehicle power system), such as Figure 1 As shown, the engine start control method of the hybrid vehicle may include the following operations:

[0041] 101. When the vehicle control terminal determines that the engine of the target vehicle needs to be started, the vehicle control terminal performs a first oil flushing operation on the clutch of the target vehicle and obtains the current vehicle speed of the target vehicle.

[0042] In the embodiment of the present invention, any vehicle that needs to start its engine can be identified as a target vehicle.

[0043] In an optional embodiment, the engine start control method of the hybrid vehicle may further include the following steps:

[0044] The vehicle control terminal obtains current operating parameters of the target vehicle, where the current operating parameters include a driving demand torque of the target vehicle and / or a battery SOC (State of Charge) value of the target vehicle;

[0045] The vehicle control terminal determines whether the current operating parameters meet the predetermined triggering conditions for the engine;

[0046] When it is determined that the current operating parameters meet the triggering condition, the vehicle control terminal determines that the engine of the target vehicle needs to be started, and triggers the execution of step 101.

[0047] In this optional embodiment, the current operating parameters also include parameters of the engine of the target vehicle, that is, when the output power of the engine is high, the vehicle control terminal determines that the engine of the target vehicle needs to be started and triggers the execution of step 101.

[0048] In this optional embodiment, the target opening value of the accelerator pedal of the target vehicle is obtained, and the required torque corresponding to the target opening value is queried from a pre-established opening value-required torque table according to the opening value-required torque correspondence relationship, as the driving required torque of the target vehicle. Each opening value of the accelerator pedal has a corresponding required torque.

[0049] In this optional embodiment, the remaining power of the battery of the target vehicle is read and the full power of the battery is obtained, and the ratio of the remaining power to the full power is taken as the battery SOC value of the target vehicle, or the battery SOC value of the target vehicle is directly read from the battery SOC display.

[0050] In this optional embodiment, as an optional implementation, if the current operating parameter includes the driving demand torque, determining whether the current operating parameter satisfies the predetermined triggering condition for the engine may include:

[0051] The vehicle control terminal determines whether the driving demand torque is greater than or equal to a predetermined demand torque threshold (for example, 200 N.m) of the target vehicle;

[0052] When it is determined that the driving demand torque is greater than or equal to the demand torque threshold, the vehicle control terminal determines that the current operating parameters meet the predetermined trigger conditions for the engine.

[0053] It can be seen that this optional implementation can automatically determine whether the vehicle meets the trigger conditions for starting the engine by intelligently judging that the vehicle's driver demand torque is greater than or equal to a predetermined demand torque threshold, thereby improving the efficiency of determining the trigger conditions for starting the engine.

[0054] In this optional embodiment, as another optional implementation, if the current operating parameter includes the battery SOC value of the target vehicle, determining whether the current operating parameter satisfies the predetermined trigger condition for the engine may include:

[0055] The vehicle control terminal determines whether the battery SOC value is less than or equal to a predetermined battery SOC value threshold value (for example, 30%) of the target vehicle;

[0056] When it is determined that the battery SOC value is less than or equal to the battery SOC value threshold, the vehicle control terminal determines that the current operating parameters meet the predetermined triggering conditions for the engine.

[0057] It can be seen that this optional implementation method can automatically determine whether the vehicle meets its triggering conditions for starting the engine by intelligently judging that the battery SOC value of the vehicle is less than the battery SOC value threshold, thereby improving the efficiency of determining the triggering conditions for starting the engine.

[0058] In this optional embodiment, further, when it is determined that the driving demand torque is greater than or equal to the demand torque threshold, and when it is determined that the battery SOC value is less than or equal to the battery SOC value threshold, it is determined that the current operating parameters meet the predetermined trigger conditions for the engine. This can improve the accuracy and reliability of determining the trigger conditions for the vehicle to start its engine.

[0059] It can be seen that this optional embodiment can intelligently determine whether the vehicle's engine needs to be started by acquiring the vehicle's battery SOC value and / or driving demand torque.

[0060] In an embodiment of the present invention, the vehicle control terminal controls the clutch of the target vehicle to perform a first oil flushing operation. Specifically, the vehicle control terminal performs the first oil flushing operation on the clutch of the target vehicle based on a rectangular oil flushing method to stabilize the oil pressure of the clutch at the contact oil pressure of the clutch. The contact oil pressure is the oil pressure when the clutch plate of the clutch contacts the pressure plate, and the contact is a pre-calibrated oil pressure, for example: 10PSI. Further, when the oil pressure of the clutch reaches the contact oil pressure, the clutch is controlled to work at the contact oil pressure for a preset time, for example: 100ms, and when the clutch works at the contact oil pressure for a preset time, step 102 is triggered.

[0061] In another optional embodiment, the engine start control method of the hybrid electric vehicle may further include the following steps:

[0062] During the first oil flushing operation on the clutch, the vehicle control terminal distributes the above-mentioned driving requirement torque to the drive motor and the generator of the target vehicle according to a predetermined vehicle energy distribution strategy, so that the sum of the torque generated by the drive motor of the target vehicle and the torque generated by the generator of the target vehicle is greater than or equal to the driving requirement torque.

[0063] In this optional embodiment, the vehicle energy distribution strategy may specifically be: distributed according to a preset ratio, for example, 2:1, that is, two-thirds of the driving demand torque is distributed to the drive motor and one-third of the driving demand torque is distributed to the generator.

[0064] It can be seen that this optional embodiment can reduce the vehicle shaking caused by the increase of the driver's required torque and improve the driver's driving safety by intelligently distributing the vehicle's driving required torque to the vehicle's drive motor and generator during the oil flushing operation on the clutch.

[0065] 102. The vehicle control terminal determines a target control strategy that matches the current vehicle speed from a predetermined control strategy set according to the current vehicle speed.

[0066] In the embodiment of the present invention, different vehicle speeds have corresponding engine start control strategies.

[0067] In the embodiment of the present invention, as an optional implementation, the vehicle control terminal determines a target control strategy matching the current vehicle speed from a predetermined control strategy set according to the current vehicle speed, which may include:

[0068] The vehicle control terminal determines whether the current vehicle speed is greater than or equal to a first preset vehicle speed threshold and less than or equal to a second preset vehicle speed threshold;

[0069] When it is determined that the current vehicle speed is greater than or equal to the first preset vehicle speed threshold and less than or equal to the second preset vehicle speed threshold, the vehicle control terminal determines a low-speed control strategy from a predetermined control strategy set as a target control strategy matching the current vehicle speed;

[0070] When it is determined that the current vehicle speed is greater than the second preset vehicle speed threshold, the vehicle control terminal determines a high-speed control strategy from a predetermined control strategy set as a target control strategy matching the current vehicle speed.

[0071] In this optional implementation, the first preset speed threshold, for example, 30 km / h, and the second preset speed threshold, for example, 60 km / h, are both calibrated speed thresholds. It should be noted that different vehicles correspond to different first preset speed thresholds and second preset speed thresholds.

[0072] In this optional embodiment, when it is determined that the current vehicle speed is less than the first preset vehicle speed threshold, the vehicle control terminal directly ends the process.

[0073] It can be seen that this optional implementation method can intelligently determine a control strategy that matches the current vehicle speed by comparing the vehicle's current speed with the preset speed threshold, thereby improving the accuracy and reliability of determining the control strategy, which is beneficial to reducing the jitter of the engine during the starting process and thereby improving the smoothness of the engine starting.

[0074] In yet another optional embodiment, before executing step 102, the engine start control method of the hybrid vehicle may further include the following steps:

[0075] The vehicle control terminal determines whether the duration that the clutch oil pressure is stable at the contact oil pressure is greater than or equal to a preset time threshold, for example: 10ms. When the judgment result is yes, step 102 is triggered; when the judgment result is no, the duration continues to be monitored until the duration reaches the preset time threshold, and step 102 is triggered.

[0076] It can be seen that this optional embodiment obtains a control strategy that matches the current speed of the vehicle only when it is determined that the duration of the oil pressure of the vehicle's clutch is stable at the contact oil pressure meets the requirement. This can reduce the occurrence of a control strategy that matches the current vehicle speed when the clutch oil pressure is too low, thereby improving the accuracy of obtaining the control strategy.

[0077] 103. The vehicle control terminal controls the engine start based on the above target control strategy.

[0078] In the embodiment of the present invention, as an optional implementation manner, the vehicle control terminal controls the engine start based on the above target control strategy, which may include:

[0079] The vehicle control terminal controls the clutch to be in a slipping state to increase the engine speed;

[0080] The vehicle control terminal determines whether the current conditions meet the predetermined ignition conditions corresponding to the ignition device of the engine. When it is determined that the current conditions meet the ignition conditions, the ignition device is controlled to ignite to start the engine.

[0081] In this optional implementation, the clutch is subjected to an oil flushing operation to control the clutch to be in a slipping state. The oil flushing operation is performed in a fast to slow manner, which can reduce the excessive real-time resistance torque transmitted to the wheel end due to excessive clutch oil pressure during the engine towing process, and the drive motor and generator cannot compensate in time or cannot compensate, resulting in the engine shaking and / or pulsating, which is conducive to ensuring the driver's driving smoothness.

[0082] In this optional implementation, further, different vehicle speeds correspond to different ignition conditions, that is, different target control strategies correspond to different ignition conditions, wherein:

[0083] If the current vehicle speed is greater than or equal to the first preset vehicle speed threshold and less than or equal to the second preset vehicle speed threshold, the vehicle control terminal determines whether the current condition meets the predetermined ignition condition corresponding to the engine ignition device, specifically: the vehicle control terminal monitors the engine speed, and when the absolute speed difference between the engine speed and the preset speed threshold of the engine (for example: 600r / min) is less than or equal to the predetermined speed difference threshold (for example: 5r / min), the clutch is depressurized and the clutch oil pressure is monitored; when the absolute value of the oil pressure difference between the clutch oil pressure and the clutch contact oil pressure is less than or equal to the first preset oil pressure difference absolute value (for example: 10PSI), the vehicle control terminal determines that the current condition meets the predetermined ignition condition corresponding to the engine ignition device. In this way, by reducing the clutch oil pressure to close to the contact oil pressure, the situation of sudden change of the engine torque due to the positive and negative change of the speed difference between the clutch active disc and the driven disc during the engine ignition process can be reduced or even avoided, which is conducive to improving the accuracy of determining the ignition condition corresponding to the ignition device, and thus improving the probability of successful engine ignition.

[0084] If the current vehicle speed is greater than the second preset vehicle speed threshold, the vehicle control terminal determines whether the current conditions meet the predetermined ignition conditions corresponding to the engine's ignition device. Specifically, the vehicle control terminal monitors the oil pressure of the clutch, and when the absolute value of the oil pressure difference between the clutch oil pressure and the first preset oil pressure threshold of the clutch (for example: 500PSI) is less than or equal to the second preset oil pressure difference absolute value (for example: 15PSI), it is determined that the current conditions meet the predetermined ignition conditions corresponding to the engine's ignition device.

[0085] In this optional implementation, the absolute value of the first preset oil pressure difference may be the same as or different from the absolute value of the second preset oil pressure difference, depending on the type of vehicle.

[0086] In this optional embodiment, when the engine is started successfully, the control unit corresponding to the engine will send an ignition success flag to the vehicle control terminal, which can remind the vehicle control terminal that the engine has been started, so as to quickly and accurately execute subsequent operations.

[0087] It can be seen that this optional implementation method increases the speed of the vehicle's engine by controlling the vehicle's clutch to be in a slipping state, and automatically starts the engine through the ignition device corresponding to the engine when the current conditions meet the preset conditions. It can also intelligently determine the ignition conditions according to the vehicle's speed, thereby improving the accuracy of determining the ignition conditions and thus improving the accuracy of starting the engine.

[0088] In yet another optional embodiment, the engine start control method of the hybrid vehicle may further include the following steps:

[0089] In the process of controlling the clutch to be in a slipping state, the vehicle control terminal determines the real-time resistance torque generated by the clutch on the wheel end of the target vehicle;

[0090] The vehicle control terminal obtains the total remaining torque capacity of the drive motor of the target vehicle and the generator of the target vehicle, the total remaining torque capacity is equal to the sum of the remaining torque capacity of the drive motor of the target vehicle and the remaining torque capacity of the generator of the target vehicle, the remaining torque capacity of the drive motor of the target vehicle is the unused torque of the rated maximum torque of the drive motor of the target vehicle at the current speed, and the remaining torque capacity of the generator of the target vehicle is the unused torque of the rated maximum torque of the generator of the target vehicle at the current speed;

[0091] The vehicle control terminal compensates the real-time resistance torque based on the torque compensation capacity of the torque compensation device to make the wheel end output a stable torque. The torque compensation device includes a drive motor of the target vehicle and / or a generator of the target vehicle. The torque compensation capacity is less than or equal to the total residual torque capacity. The stable torque is a torque determined based on the torque output by the wheel when it is determined that the engine needs to be started.

[0092] In this optional embodiment, as an optional implementation manner, the vehicle control terminal determines the real-time resistance torque generated by the clutch on the wheel end of the target vehicle, which may include:

[0093] The vehicle control terminal determines the real-time oil pressure of the clutch, and queries the torque corresponding to the real-time oil pressure from a pre-established oil pressure-torque correspondence table based on a predetermined oil pressure-torque correspondence, as the real-time resistance torque generated by the clutch on the wheel end of the target vehicle.

[0094] In this optional embodiment, the higher the real-time oil pressure of the clutch is, the greater the real-time resistance torque generated on the wheel end of the target vehicle.

[0095] It can be seen that this optional implementation can quickly obtain the real-time resistance torque generated by the clutch on the wheel end of the vehicle through the oil pressure-torque correspondence relationship.

[0096] In this optional embodiment, the remaining torque capacity of the drive motor of the target vehicle is the unused torque of the rated maximum torque of the drive motor of the target vehicle at the current speed, that is, the sum of the remaining torque capacity of the drive motor of the target vehicle and the torque output by the drive motor during the above-mentioned first oil flushing operation on the clutch is equal to the rated maximum torque of the drive motor at the current speed.

[0097] In this optional embodiment, the remaining torque capacity of the generator of the target vehicle is the unused torque of the rated maximum torque of the generator of the target vehicle at the current speed, that is, the sum of the remaining torque capacity of the generator of the target vehicle and the torque output by the generator during the above-mentioned first oil flushing operation on the clutch is equal to the rated maximum torque of the generator at the current speed.

[0098] In this optional embodiment, the vehicle control terminal compensates the real-time resistance torque based on the torque compensation capacity of the torque compensation device so that the wheel end outputs a stable torque, that is, the vehicle control terminal offsets the reduction in the output torque of the wheel end caused by the real-time resistance torque based on the torque compensation capacity of the torque compensation device. Among them, the magnitude of the stable torque output by the wheel end can be equal to the torque output by the wheel when it is determined that the engine needs to be started, and can also float around the torque output by the wheel when it is determined that the engine needs to be started. For example: when it is determined that the torque output by the wheel is equal to 200N.m when the engine needs to be started, the torque output by the wheel of 198N.m-202N.m can be considered as a stable torque.

[0099] In this optional embodiment, it should be noted that the residual torque capacity of one of the torque compensation devices (e.g., the drive motor) can be used to compensate the real-time resistance torque first. When the capacity of one of the devices is insufficient, the remaining real-time resistance torque can be compensated based on another device (e.g., the generator); or the drive motor and the generator can be used together to compensate the real-time resistance torque. This optional embodiment is not limited. This can improve the flexibility and control of the clutch in compensating the real-time resistance torque generated by the wheel end.

[0100] It can be seen that this optional embodiment, in the process of controlling the vehicle's clutch to be in a sliding film state, uses the remaining torque capacity of the vehicle's drive motor and generator to compensate for the real-time resistance torque generated by the clutch on the vehicle's wheel end. This can reduce or even prevent the vehicle from shaking due to the real-time resistance torque reducing the output torque of the wheel, thereby improving the driver's driving smoothness and ensuring the driver's safety and vehicle performance.

[0101] In yet another optional embodiment, before compensating the real-time resistance torque based on the torque compensation capacity of the torque compensation device to make the wheel end output a stable torque, the engine start control method of the hybrid vehicle may further include the following steps:

[0102] The vehicle control terminal determines whether the total remaining torque capacity is greater than or equal to a predetermined torque capacity threshold;

[0103] When it is determined that the total remaining torque capacity is greater than or equal to the torque capacity threshold, the vehicle control terminal triggers the execution of the above-mentioned operation of compensating the real-time resistance torque based on the torque compensation capacity of the torque compensation device so that the wheel end outputs a stable torque;

[0104] When it is determined that the total remaining torque capacity is less than the torque capacity threshold, the vehicle control terminal controls the drive motor of the target vehicle to operate at a first torque and controls the generator of the target vehicle to operate at a second torque;

[0105] The first torque is the torque output by the drive motor of the target vehicle when the above-mentioned determination of whether the total remaining torque capacity is greater than or equal to the predetermined torque capacity threshold is performed;

[0106] The second torque is the torque output by the generator of the target vehicle when the above-mentioned determination of whether the total remaining torque capacity is greater than or equal to the predetermined torque capacity threshold is performed;

[0107] If the current vehicle speed is greater than or equal to the first preset vehicle speed threshold and less than or equal to the second preset vehicle speed threshold, the above torque capacity threshold is the first torque capacity threshold; if the current vehicle speed is greater than the second preset vehicle speed threshold, the above torque capacity threshold is the second torque capacity threshold.

[0108] It can be seen that this optional embodiment first determines whether the residual torque capacity of the vehicle's drive motor and generator is sufficient. When it is sufficient, it executes the subsequent compensation of the real-time resistance torque generated by the clutch on the wheel end based on the residual torque capacity; when the residual torque capacity is insufficient, the drive motor and generator are directly controlled to maintain a constant output torque, which can improve the compensation accuracy of the real-time resistance torque, thereby further ensuring the driving smoothness of the driver.

[0109] In yet another optional embodiment, the engine start control method of the hybrid vehicle may further include the following steps:

[0110] In the process of performing the pressure reduction operation on the clutch, the vehicle control terminal reduces the output torque of the drive motor of the target vehicle and / or the output torque of the generator of the target vehicle to make the wheel end operate at a stable torque.

[0111] This optional embodiment corresponds to the ignition stage of the engine. When the total remaining torque capacity of the drive motor of the target vehicle and the generator of the target vehicle is greater than or equal to a predetermined torque capacity threshold, the vehicle control terminal reduces the output torque of the drive motor of the target vehicle and / or the output torque of the generator of the target vehicle, so that the wheel end works with a stable torque. Specifically: the vehicle control terminal reduces the output torque of the drive motor of the target vehicle and / or the output torque of the generator of the target vehicle to the torque output when the first oil flushing operation is performed on the clutch, so that the wheel end works with a stable torque; when the total remaining torque capacity of the drive motor of the target vehicle and the generator of the target vehicle is less than a predetermined torque capacity threshold, the vehicle control terminal reduces the output torque of the drive motor of the target vehicle and / or the output torque of the generator of the target vehicle, so that the wheel end works with a stable torque. Specifically: the vehicle control terminal reduces the output torque of the drive motor of the target vehicle and / or the output torque of the generator of the target vehicle to their preset torque thresholds, so that the wheel end works with a stable torque. In this way, by selecting different compensation torque reduction methods according to the total residual torque capacity of the drive motor and the generator, the driving smoothness of the driver can be further improved.

[0112] It can be seen that this optional embodiment can reduce the sudden acceleration of the vehicle caused by the resistance torque generated by the engine on the wheel end gradually dropping to 0, by reducing the output torque of the drive motor and / or the ignition generator during the process of clutch pressure reduction, thereby further improving the driver's driving smoothness and driving safety.

[0113] In yet another optional embodiment, the engine start control method of the hybrid vehicle may further include the following steps:

[0114] In the process of controlling the ignition device to ignite to start the engine, the vehicle control terminal controls the clutch to operate at the target oil pressure, controls the drive motor of the target vehicle to maintain the third torque, and controls the generator of the target vehicle to maintain the fourth torque;

[0115] The target oil pressure is the oil pressure corresponding to the clutch when the above-mentioned control ignition device ignites to start the operation of starting the engine;

[0116] The third torque is the torque output by the drive motor of the target vehicle after the clutch slip ends; the fourth torque is the torque output by the generator of the target vehicle after the clutch slip ends.

[0117] It can be seen that during the ignition process of the engine, this optional embodiment can maintain the speed difference between the active disc and the driven disc of the clutch in a fixed direction by maintaining the oil pressure of the clutch in the previous stage and maintaining the output torque of the drive motor and generator in the previous stage, thereby reducing the occurrence of unsuccessful engine starting and further improving the driver's driving smoothness and driving safety during the engine starting process.

[0118] It can be seen that implementation Figure 1 The described hybrid vehicle engine start control method can obtain the current speed of the target vehicle when determining that the engine of the target vehicle needs to be started, select a control strategy that matches the current speed of the target vehicle, and control the vehicle engine start according to the control strategy. In the process of starting the vehicle engine, the driving smoothness of the car driver can be ensured, and the torque impact caused to the vehicle by the engine during the starting process can be reduced, thereby improving the driver's driving safety. By controlling the engine start through a control strategy that matches the vehicle speed, the engine start time can also be shortened.

[0119] Embodiment 2

[0120] See also Figure 2 , Figure 2 is a flow chart of another hybrid vehicle engine start control method disclosed in an embodiment of the present invention. The method is applied to a vehicle control terminal (also known as a vehicle power system), such as Figure 2 As shown, the engine start control method of the hybrid vehicle may include the following operations:

[0121] 201. When the vehicle control terminal determines that the engine of the target vehicle needs to be started, the vehicle control terminal performs a first oil flushing operation on the clutch of the target vehicle and obtains the current vehicle speed of the target vehicle.

[0122] 202. The vehicle control terminal determines a target control strategy that matches the current vehicle speed from a predetermined control strategy set according to the current vehicle speed.

[0123] 203. The vehicle control terminal controls the engine to start based on the target control strategy. In the embodiment of the present invention, for the description of steps 201 to 203, please refer to the detailed description of steps 101 to 103 in the first embodiment, which will not be repeated in the present invention.

[0124] 204. The vehicle control terminal controls the oil pressure of the clutch to maintain the contact oil pressure of the clutch, controls the drive motor of the target vehicle to maintain the reduced output torque, controls the generator of the target vehicle to maintain the reduced output torque, and determines a first speed output by the generator of the target vehicle.

[0125] In the embodiment of the present invention, the target vehicle's drive motor maintains a reduced output torque and the target vehicle's generator maintains a reduced output torque are respectively the torques output when the engine is ignited and the clutch oil pressure is reduced to its contact oil pressure.

[0126] 205. The vehicle control terminal controls the engine to operate at a target self-idling speed so that the speed corresponding to the driving plate of the clutch is synchronized with the speed corresponding to the driven plate of the clutch, and the target self-idling speed is equal to the first speed.

[0127] In the embodiment of the present invention, after the engine is successfully ignited and started, the clutch sends a self-idle request to the engine, and the self-idle request includes a self-idle speed at which the engine operates, wherein the self-idle speed is equal to the speed of the generator.

[0128] It can be seen that after the engine is successfully started, the embodiment of the present invention further automatically controls the speed of the engine to operate at the speed of the generator while keeping the output torque of the drive motor and the generator unchanged, so that the speed between the active plate and the driven plate of the clutch can be synchronized, which is beneficial for the engine to be in a stable working state, thereby further improving the driving smoothness of the driver.

[0129] As an optional embodiment, the engine start control method of the hybrid vehicle may further include the following steps:

[0130] When the speed corresponding to the active disk is synchronized with the speed corresponding to the driven disk, the vehicle control terminal determines the absolute value of the speed difference between the active disk and the driven disk;

[0131] When the absolute value of the speed difference is less than or equal to a preset speed difference threshold (for example: 3r / s), the vehicle control terminal performs a second oil flushing operation on the clutch until the oil pressure of the clutch reaches a preset clamping oil pressure threshold (for example: 200PSI), and cancels the compensation torque of the target vehicle's drive motor and the compensation torque of the target vehicle's generator.

[0132] In this optional embodiment, the description of the second oil flushing operation on the clutch can be referred to the detailed description of the first oil flushing operation in the first embodiment, and this optional embodiment will not be repeated. It should be noted that the second oil flushing operation adopts a triangular oil flushing method, that is, a linear oil flushing method, and after the second oil flushing operation, the oil pressure of the clutch is greater than the oil pressure of the clutch after the first oil flushing operation.

[0133] In this optional embodiment, the compensation torque of the drive motor of the target vehicle and the compensation torque of the generator of the target vehicle are canceled, that is, the output torque of the drive motor and the output torque of the generator are controlled to be maintained at the torque output when the first oil flushing operation is performed on the clutch.

[0134] It can be seen that this optional embodiment further determines the speed difference between the driving plate and the driven plate of the clutch after the speed difference is synchronized, and when the speed difference is small, performs an oil flushing operation on the clutch, and cancels the compensating torque of the drive motor and / or the generator, which can make the driving plate and the driven plate of the clutch quickly and stably engage, so that the engine can work more stably, thereby further improving the driving smoothness of the driver, improving the driving safety of the driver and ensuring the working performance of the engine, clutch, drive motor and generator.

[0135] It can be seen that implementation Figure 2 The engine start control method of the hybrid vehicle described can obtain the current speed of the target vehicle when it is determined that the engine of the target vehicle needs to be started, select a control strategy that matches the current speed of the target vehicle, and control the engine start of the vehicle according to the control strategy. In the process of starting the engine of the vehicle, the driving smoothness of the driver can be ensured, and the torque impact caused by the engine to the vehicle during the starting process can be reduced, thereby improving the driving safety of the driver. By controlling the engine start through the control strategy that matches the vehicle speed, the engine start time can also be shortened. In addition, the speed between the active plate and the driven plate of the clutch can be synchronized, which is conducive to the engine being in a stable working state, thereby further improving the driving smoothness of the driver.

[0136] Embodiment 3

[0137] See also Figure 3 , Figure 3 is a flow chart of another hybrid vehicle engine start control method disclosed in an embodiment of the present invention. The method is applied to a vehicle control terminal (also known as a vehicle power system), such as Figure 3 As shown, the engine start control method of the hybrid vehicle may include the following operations:

[0138] 301. When determining that the engine of the target vehicle needs to be started, the vehicle control terminal performs a first oil flushing operation on the clutch of the target vehicle and obtains the current vehicle speed of the target vehicle.

[0139] 302. The vehicle control terminal determines a target control strategy that matches the current vehicle speed from a predetermined control strategy set according to the current vehicle speed.

[0140] 303. The vehicle control terminal controls the engine start based on the target control strategy.

[0141] In the embodiment of the present invention, for the related description of step 301 to step 303, please refer to the detailed description of step 101 to step 103 in the first embodiment, and the present invention will not repeat them any more.

[0142] 304. The vehicle control terminal controls the oil pressure of the clutch to maintain the oil pressure output by the clutch when the engine is started, controls the drive motor of the target vehicle to maintain the fifth torque, and controls the generator of the target vehicle to maintain the sixth torque.

[0143] In the embodiment of the present invention, the fifth torque is the torque output by the drive motor of the target vehicle when the operation of controlling the ignition device to ignite to start the engine in the first embodiment is performed.

[0144] In the embodiment of the present invention, the sixth torque is the torque output by the generator of the target vehicle when the operation of controlling the ignition device to ignite to start the engine in the first embodiment is executed. In the embodiment of the present invention, the oil pressure of the clutch is stabilized at the contact oil pressure of the clutch, that is, the oil pressure difference between the oil pressure of the clutch and the contact oil pressure of the clutch is a preset oil pressure difference, for example: 5PSI, etc.

[0145] 305. The vehicle control terminal obtains the second speed of the generator output of the target vehicle and the third speed of the engine, and performs PI control on the output torque of the engine according to the second speed and the third speed, so that the speed corresponding to the active plate of the clutch is synchronized with the speed corresponding to the driven plate of the clutch.

[0146] In this optional embodiment, the vehicle control terminal performs PI control on the output torque of the engine according to the second speed and the third speed, so that the speed corresponding to the active disk of the clutch is synchronized with the speed corresponding to the driven disk of the clutch. Specifically: the vehicle control terminal performs PI control on the engine according to the proportional integral control formula, so that the speed corresponding to the active disk of the clutch is synchronized with the speed corresponding to the driven disk of the clutch, wherein the proportional integral control formula is:

[0147] T=k p (n 1 -n 2 )+k i ∫(n 1 -n 2 )dt

[0148] Where T is the output torque required by the engine; k p and k i is the proportional integral term, and k p and k i All greater than 0; n 1 is the second speed of the generator output; n 2 It is the third speed of the engine output.

[0149] It can be seen that after the engine is successfully started, the embodiment of the present invention further performs PI control on the engine in combination with the engine speed and the generator speed while keeping the output torque of the drive motor and the generator unchanged, so that the speed between the active plate and the driven plate of the clutch can be synchronized, which is beneficial for the engine to be in a stable working state, thereby further improving the driving smoothness of the driver.

[0150] As an optional embodiment, the engine start control method of the hybrid vehicle may further include the following steps:

[0151] When the speed corresponding to the active disk is synchronized with the speed corresponding to the driven disk, the vehicle control terminal determines the absolute value of the speed difference between the active disk and the driven disk;

[0152] When the absolute value of the speed difference is less than or equal to a preset speed difference threshold (for example, 5 r / s), the vehicle control terminal performs a second oil flushing operation on the clutch until the oil pressure of the clutch reaches a preset clamping oil pressure threshold (for example, 30 PSI), and cancels the compensation torque of the target vehicle's drive motor and the compensation torque of the target vehicle's generator.

[0153] It should be noted that, for the relevant description of this optional embodiment, please refer to the detailed description of the corresponding optional embodiment in Embodiment 2, which will not be repeated here.

[0154] It can be seen that this optional embodiment further determines the speed difference between the driving plate and the driven plate of the clutch after the speed difference is synchronized, and when the speed difference is small, performs an oil flushing operation on the clutch, and cancels the compensating torque of the drive motor and / or the generator, which can make the driving plate and the driven plate of the clutch quickly and stably engage, so that the engine can work more stably, thereby further improving the driving smoothness of the driver, improving the driving safety of the driver and ensuring the working performance of the engine, clutch, drive motor and generator.

[0155] It can be seen that implementation Figure 3The engine start control method of the hybrid vehicle described can obtain the current speed of the target vehicle when determining that the engine of the target vehicle needs to be started, select a control strategy that matches the current speed of the target vehicle, and control the engine start of the vehicle according to the control strategy. In the process of starting the engine of the vehicle, the driving smoothness of the driver can be ensured, and the torque impact caused by the engine to the vehicle during the starting process can be reduced, thereby improving the driving safety of the driver. By controlling the engine start through the control strategy that matches the vehicle speed, the engine start time can also be shortened. In addition, after the engine is successfully started, the engine can be further PI-controlled by combining the engine speed and the generator speed while keeping the output torque of the drive motor and the generator unchanged, so that the speed between the active plate and the driven plate of the clutch can be synchronized, thereby facilitating the engine to be in a stable working state, thereby further improving the driving smoothness of the driver.

[0156] Embodiment 4

[0157] See also Figure 4 , Figure 4 Schematic diagram of the structure of an engine start control device for a hybrid vehicle disclosed in an embodiment of the present invention. Figure 4 As shown, the engine start control device of the hybrid vehicle may include a fuel charging module 401, an acquisition module 402, a first determination module 403 and a first control module 404, wherein:

[0158] The oil flushing module 401 is used to perform an oil flushing operation on the clutch of the target vehicle when it is determined that the engine of the target vehicle needs to be started.

[0159] The acquisition module 402 is used to acquire the current speed of the target vehicle.

[0160] The first determination module 403 is used to determine a target control strategy matching the current vehicle speed from a predetermined control strategy set according to the current vehicle speed.

[0161] The first control module 404 is configured to control the engine start based on a target control strategy.

[0162] It can be seen that implementation Figure 4The engine start control device of the hybrid vehicle described can obtain the current speed of the target vehicle when determining that the engine of the target vehicle needs to be started, select a control strategy that matches the current speed of the target vehicle, and control the engine start of the vehicle according to the control strategy. In the process of starting the engine of the vehicle, the driving smoothness of the car driver can be ensured, and the torque impact caused by the engine to the vehicle during the starting process can be reduced, thereby improving the driving safety of the driver. By controlling the engine start through a control strategy that matches the vehicle speed, the engine start time can also be shortened.

[0163] In an optional embodiment, Figure 4 Based on the engine start control device of the hybrid vehicle described above, the first determination module 403 may include a first judgment submodule 4031 and a first determination submodule 4032. At this time, the engine start control device of the hybrid vehicle may be as follows Figure 5 As shown, Figure 5 It is a structural schematic diagram of another hybrid vehicle engine start control device, wherein: the first judgment submodule 4031 is used to judge whether the current vehicle speed is greater than or equal to a first preset vehicle speed threshold and less than or equal to a second preset vehicle speed threshold.

[0164] The first determination submodule 4032 is used to determine a low-speed control strategy from a predetermined control strategy set as a target control strategy matching the current vehicle speed when the first judgment submodule 4031 determines that the current vehicle speed is greater than or equal to a first preset vehicle speed threshold and less than or equal to a second preset vehicle speed threshold.

[0165] The first determination submodule 4032 is further used to determine a high-speed control strategy from a predetermined control strategy set as a target control strategy matching the current vehicle speed when the first judgment submodule 4031 determines that the current vehicle speed is greater than a second preset vehicle speed threshold.

[0166] It can be seen that implementation Figure 5 The engine starting control device of the hybrid vehicle described can intelligently determine a control strategy that matches the current vehicle speed by comparing the vehicle's current vehicle speed with a preset vehicle speed threshold, thereby improving the accuracy and reliability of determining the control strategy, thereby helping to reduce the jitter of the engine during the starting process and thereby improving the smoothness of the engine starting.

[0167] In another optional embodiment, Figure 5 As shown, the first control module 404 includes a control submodule 4041 and a second judgment submodule 4042, wherein:

[0168] The control submodule 4041 is used to control the clutch to be in a slipping state to increase the speed of the engine.

[0169] The second judgment submodule 4042 is used to judge whether the current condition satisfies the predetermined ignition condition corresponding to the ignition device of the engine.

[0170] The control submodule 4041 is used to control the ignition device to ignite to start the engine when the second judgment submodule determines that the current condition meets the ignition condition.

[0171] It can be seen that implementation Figure 5 The engine start control device of the hybrid vehicle described can also increase the speed of the vehicle's engine by controlling the vehicle's clutch to be in a slipping state, and automatically start the engine through an ignition device corresponding to the engine when the current conditions meet the preset conditions. In another optional embodiment, Figure 5 As shown, the first control module 404 further includes a second determination submodule 4043, an acquisition submodule 4044 and a torque compensation submodule 4045, wherein:

[0172] The second determination submodule 4043 is used to determine the real-time resistance torque generated by the clutch on the wheel end of the target vehicle when the control submodule 4041 controls the clutch to be in a slipping state.

[0173] The acquisition submodule 4044 is used to obtain the total remaining torque capacity of the drive motor of the target vehicle and the generator of the target vehicle, where the total remaining torque capacity is equal to the sum of the remaining torque capacity of the drive motor of the target vehicle and the remaining torque capacity of the generator of the target vehicle. The remaining torque capacity of the drive motor of the target vehicle is the unused torque of the rated maximum torque of the drive motor of the target vehicle at the current speed, and the remaining torque capacity of the generator of the target vehicle is the unused torque of the rated maximum torque of the generator of the target vehicle at the current speed.

[0174] The torque compensation submodule 4045 is used to compensate the real-time resistance torque based on the torque compensation capacity of the torque compensation device so that the wheel end outputs a stable torque. The torque compensation device includes a drive motor of the target vehicle and / or a generator of the target vehicle. The torque compensation capacity is less than or equal to the total remaining torque capacity. The stable torque is a torque determined based on the torque output by the wheel when it is determined that the engine needs to be started.

[0175] It can be seen that implementation Figure 5The engine starting control device of the described hybrid vehicle can also compensate for the real-time resistance torque generated by the clutch on the wheel end of the vehicle by using the remaining torque capacity of the vehicle's drive motor and generator while controlling the vehicle's clutch to be in a sliding film state. This can reduce or even prevent the vehicle from shaking due to the real-time resistance torque reducing the output torque of the wheel, thereby improving the driver's driving smoothness and ensuring the driver's safety and vehicle performance.

[0176] In yet another optional embodiment, Figure 5 As shown, the second judgment submodule 4042 is also used to determine whether the total remaining torque capacity is greater than or equal to a predetermined torque capacity threshold before the torque compensation submodule 4045 compensates the real-time resistance torque based on the torque compensation capacity of the torque compensation device to make the wheel end output a stable torque.

[0177] The torque compensation submodule 4045 is specifically used for:

[0178] When the second judgment submodule 4042 determines that the total remaining torque capacity is greater than or equal to the torque capacity threshold, the real-time resistance torque is compensated based on the torque compensation capacity of the torque compensation device to make the wheel end output a stable torque.

[0179] The control submodule 4041 is also used to control the drive motor of the target vehicle to operate at the first torque and the generator of the target vehicle to operate at the second torque when the second judgment submodule 4042 determines that the total remaining torque capacity is less than the torque capacity threshold.

[0180] The first torque is the torque output by the drive motor of the target vehicle when the second judgment submodule 4042 performs the above-mentioned judgment on whether the total remaining torque capacity is greater than or equal to the predetermined torque capacity threshold;

[0181] The second torque is the torque output by the generator of the target vehicle when the second judgment submodule 4042 executes the above-mentioned judgment on whether the total remaining torque capacity is greater than or equal to the predetermined torque capacity threshold.

[0182] If the current vehicle speed is greater than or equal to the first preset vehicle speed threshold and less than or equal to the second preset vehicle speed threshold, the torque capacity threshold is the first torque capacity threshold; if the current vehicle speed is greater than the second preset vehicle speed threshold, the torque capacity threshold is the second torque capacity threshold.

[0183] It can be seen that implementation Figure 5The engine starting control device of the described hybrid vehicle can also first determine whether the residual torque capacity of the vehicle's drive motor and generator is sufficient. When it is sufficient, it will execute the subsequent compensation for the real-time resistance torque generated by the clutch on the wheel end based on the residual torque capacity; when the residual torque capacity is insufficient, it directly controls the drive motor and generator to maintain a constant output torque, which can improve the compensation accuracy of the real-time resistance torque, thereby further ensuring the driving smoothness of the driver.

[0184] In yet another optional embodiment, Figure 6 As shown, the second judgment submodule 4042 includes a first monitoring unit 40421, a voltage reduction unit 40422 and a first determination unit 40423, wherein:

[0185] The first monitoring unit 40421 is used to monitor the engine speed if the current vehicle speed is greater than or equal to the first preset vehicle speed threshold and less than or equal to the second preset vehicle speed threshold.

[0186] The pressure reduction unit 40422 is used to perform a pressure reduction operation on the clutch when the absolute speed difference between the engine speed and the preset speed threshold of the engine is less than or equal to a predetermined speed difference threshold.

[0187] The first monitoring unit 40421 is also used to monitor the oil pressure of the clutch.

[0188] The first determination unit 40423 is used to determine that the current condition meets the predetermined ignition condition corresponding to the ignition device of the engine when the absolute value of the oil pressure difference between the clutch oil pressure and the clutch contact oil pressure is less than or equal to the first preset oil pressure difference absolute value.

[0189] It can be seen that implementation Figure 6 The engine starting control device of the described hybrid vehicle can also reduce the oil pressure of the clutch to close to the contact oil pressure, thereby reducing or even avoiding the sudden change of the engine torque due to the positive or negative change of the speed difference between the clutch driving plate and the driven plate during the engine ignition process, thereby helping to improve the accuracy of determining the ignition conditions corresponding to the ignition device, thereby increasing the probability of successful engine ignition.

[0190] In yet another optional embodiment, Figure 7 As shown, the second judgment submodule 4042 includes a second monitoring unit 40424 and a second determination unit 40425, wherein:

[0191] The second monitoring unit 40424 is used to monitor the oil pressure of the clutch if the current vehicle speed is greater than a second preset vehicle speed threshold;

[0192] The second determination unit 40425 is used to determine that the current condition meets the predetermined ignition condition corresponding to the ignition device of the engine when the absolute value of the oil pressure difference between the clutch oil pressure and the first preset oil pressure threshold of the clutch is less than or equal to the second preset oil pressure difference absolute value.

[0193] It can be seen that implementation Figure 7 The engine start control device of the hybrid vehicle described can also increase the oil pressure of the clutch when the vehicle speed is high, and when the oil pressure of the clutch reaches the requirement, it can intelligently determine whether the current conditions meet the ignition conditions of the engine's ignition device.

[0194] In yet another optional embodiment, Figure 5 As shown, the first control module 404 further includes a torque reduction submodule 4046, wherein:

[0195] The torque reduction submodule 4046 is used to reduce the output torque of the drive motor of the target vehicle and / or the output torque of the generator of the target vehicle during the process of the second judgment submodule 4042 performing the pressure reduction operation on the clutch, so that the wheel end works with a stable torque.

[0196] It can be seen that implementation Figure 5 The engine starting control device of the hybrid vehicle described can also reduce the output torque of the drive motor and / or the ignition generator during the process of clutch pressure reduction, thereby reducing the sudden acceleration of the vehicle caused by the resistance torque generated by the engine on the wheel end gradually dropping to 0, thereby further improving the driving smoothness and driving safety of the driver.

[0197] In yet another optional embodiment, Figure 5 As shown, the control submodule 4041 is also used to control the clutch to operate at a target oil pressure during the process of controlling the ignition device to ignite to start the engine.

[0198] The control submodule 4041 is further used to control the drive motor of the target vehicle to maintain the third torque and control the generator of the target vehicle to maintain the fourth torque.

[0199] The target oil pressure is the oil pressure corresponding to the clutch when the above-mentioned control ignition device ignites to start the operation of starting the engine;

[0200] The third torque is the torque output by the drive motor of the target vehicle after the clutch slip ends; the fourth torque is the torque output by the generator of the target vehicle after the clutch slip ends.

[0201] It can be seen that implementation Figure 5The engine starting control device of the described hybrid vehicle can also maintain the speed difference between the active disc and the driven disc of the clutch in a fixed direction during the engine ignition process by maintaining the oil pressure of the clutch in the previous stage and maintaining the output torque of the drive motor and the generator in the previous stage, thereby reducing the occurrence of unsuccessful engine starting and further improving the driver's driving smoothness and driving safety during the engine starting process.

[0202] In yet another optional embodiment, Figure 5 Based on the engine start control device of the hybrid vehicle described above, the engine start control device of the hybrid vehicle may further include a second control module 405 and a second determination module 406. In this case, the engine start control device of the hybrid vehicle may be as follows Figure 8 As shown, Figure 8 This is a schematic diagram of the structure of another hybrid vehicle engine start control device, wherein:

[0203] The second control module 405 is configured to control the oil pressure of the clutch to be maintained at the contact point oil pressure of the clutch after the first control module 404 controls the engine to start based on the target control strategy.

[0204] The second control module 405 is further used to control the drive motor of the target vehicle to maintain the reduced output torque and control the generator of the target vehicle to maintain the reduced output torque.

[0205] The second determination module 406 is configured to determine a first rotation speed output by a generator of the target vehicle.

[0206] The second control module 405 is also used to control the engine to operate at a target self-idling speed so that the speed corresponding to the active disc of the clutch is synchronized with the speed corresponding to the driven disc of the clutch, and the target self-idling speed is equal to the first speed.

[0207] In this optional embodiment, after the first control module 404 completes the operation of controlling the engine start based on the target control strategy, the second control module 405 can be triggered to perform the operation of controlling the clutch oil pressure to maintain the clutch contact oil pressure.

[0208] In this optional embodiment, after the first control module 404 completes the above-mentioned operation of controlling the engine start-up based on the target control strategy, the second control module 405 can be triggered to execute the above-mentioned operation of controlling the drive motor of the target vehicle to maintain the reduced output torque and controlling the generator of the target vehicle to maintain the reduced output torque.

[0209] It can be seen that implementation Figure 8The engine starting control device of the hybrid vehicle described can, after the engine is successfully started, further automatically control the engine speed to operate at the speed of the generator while keeping the output torque of the drive motor and the generator unchanged, so that the speed between the active plate and the driven plate of the clutch can be synchronized, which is beneficial for the engine to be in a stable working state, thereby further improving the driving smoothness of the driver.

[0210] In yet another optional embodiment, Figure 5 Based on the engine start control device of the hybrid vehicle described above, the engine start control device of the hybrid vehicle may further include an oil pressure maintaining module 407 and a third control module 408. In this case, the engine start control device of the hybrid vehicle may be as follows Fig. 9 As shown, Fig. 9 This is a schematic diagram of the structure of another hybrid vehicle engine start control device, wherein:

[0211] The oil pressure maintaining module 407 is used to control the oil pressure of the clutch to maintain the oil pressure output by the clutch when the engine is started after the first control module 404 controls the engine to start based on the target control strategy.

[0212] The third control module 408 is used to control the driving motor of the target vehicle to maintain a fifth torque and control the generator of the target vehicle to maintain a sixth torque.

[0213] The acquisition module 402 is further configured to acquire a second rotational speed output by a generator of the target vehicle and a third rotational speed of the engine.

[0214] The third control module 408 is further configured to perform PI control on the output torque of the engine according to the second speed and the third speed, so as to synchronize the speed corresponding to the driving plate of the clutch with the speed corresponding to the driven plate of the clutch.

[0215] The fifth torque is the torque output by the drive motor of the target vehicle when the above-mentioned operation of controlling the ignition device to ignite to start the engine is performed;

[0216] The sixth torque is a torque output by the generator of the target vehicle when the operation of controlling the ignition device to ignite to start the engine is performed.

[0217] It can be seen that implementation Fig. 9The engine starting control device of the hybrid vehicle described can, after the engine is successfully started, further perform PI control on the engine by combining the engine speed and the generator speed while keeping the output torque of the drive motor and the generator unchanged, so as to synchronize the speeds between the driving plate and the driven plate of the clutch, thereby facilitating the engine to be in a stable working state, thereby further improving the driving smoothness of the driver.

[0218] In yet another optional embodiment, Figure 8 or Fig. 9 As shown, the engine start control device of the hybrid vehicle may further include a third determination module 409 and a torque cancellation module 410, wherein:

[0219] The third determination module 409 is used to determine the absolute value of the speed difference between the active disk and the driven disk when the speed corresponding to the active disk is synchronized with the speed corresponding to the driven disk.

[0220] The oil flushing module 401 is also used to perform a second oil flushing operation on the clutch when the absolute value of the speed difference is less than or equal to a preset speed difference threshold, until the oil pressure of the clutch reaches a preset clamping oil pressure threshold.

[0221] The torque cancellation module 410 is used to cancel the compensation torque of the drive motor of the target vehicle and the compensation torque of the generator of the target vehicle.

[0222] It can be seen that implementation Figure 8 or Fig. 9 The engine starting control device of the described hybrid vehicle can also further determine the speed difference between the driving plate and the driven plate of the clutch after the speed difference is synchronized, and when the speed difference is small, perform an oil flushing operation on the clutch and cancel the compensating torque of the drive motor and / or the generator, so that the driving plate and the driven plate of the clutch can be quickly and stably engaged, thereby making the engine work more stably, thereby further improving the driving smoothness of the driver, improving the driving safety of the driver and ensuring the working performance of the engine, clutch, drive motor and generator.

[0223] Embodiment 5

[0224] See also Fig.10 , Fig.10 This is another hybrid vehicle engine start control device disclosed in an embodiment of the present invention. Fig.10 As shown, the engine start control device of the hybrid vehicle may include:

[0225] A memory 1001 storing executable program codes;

[0226] A processor 1002 coupled to the memory 1001;

[0227] The processor 1002 calls the executable program code stored in the memory 1001 to execute the steps of the engine start control method for a hybrid vehicle described in any one of the first to third embodiments.

[0228] Embodiment 5

[0229] An embodiment of the present invention discloses a computer-readable storage medium storing a computer program for electronic data exchange, wherein the computer program enables a computer to execute the steps of the engine start control method for a hybrid vehicle described in any one of Embodiments 1 to 3.

[0230] Embodiment 6

[0231] An embodiment of the present invention discloses a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program, and the computer program is operable to enable a computer to execute the steps of the engine start control method for a hybrid vehicle described in any one of Embodiments 1 to 3.

[0232] The device embodiments described above are only illustrative, wherein the modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules, i.e., they may be located in one place, or they may be distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative work.

[0233] Through the specific description of the above embodiments, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the above technical solution can be essentially or partly contributed to the prior art in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, and the storage medium includes a read-only memory (ROM), a random access memory (RAM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electronically erasable rewritable read-only memory (EEPROM), a compact disc (CD-ROM) or other optical disc storage, magnetic disk storage, magnetic tape storage, or any other computer-readable medium that can be used to carry or store data.

[0234] Finally, it should be noted that the engine start control method and device for a hybrid vehicle disclosed in the embodiment of the present invention disclose only the preferred embodiments of the present invention, which are only used to illustrate the technical solution of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for controlling engine start of a hybrid vehicle, characterized in that: The method comprises: When it is determined that the engine of the target vehicle needs to be started, a first oil flushing operation is performed on the clutch of the target vehicle, and a current vehicle speed of the target vehicle is obtained; Determining a target control strategy matching the current vehicle speed from a predetermined control strategy set according to the current vehicle speed, and controlling the engine start based on the target control strategy; The controlling the engine start based on the target control strategy includes: Controlling the clutch to be in a slipping state to increase the speed of the engine; Determining whether the current condition satisfies a predetermined ignition condition corresponding to an ignition device of the engine, and when it is determined that the current condition satisfies the ignition condition, controlling the ignition device to ignite to start the engine; Among them, when the current vehicle speed is greater than or equal to a first preset vehicle speed threshold and less than or equal to a second preset vehicle speed threshold, the current condition is judged by the engine speed and the oil pressure of the clutch; when the current vehicle speed is greater than the second preset vehicle speed threshold, the current condition is judged by the oil pressure of the clutch.

2. The engine start control method of a hybrid vehicle according to claim 1, characterized in that: The step of determining a target control strategy matching the current vehicle speed from a predetermined set of control strategies according to the current vehicle speed includes: Determining whether the current vehicle speed is greater than or equal to the first preset vehicle speed threshold and less than or equal to the second preset vehicle speed threshold; When it is determined that the current vehicle speed is greater than or equal to the first preset vehicle speed threshold and less than or equal to the second preset vehicle speed threshold, a low-speed control strategy is determined from a predetermined control strategy set as a target control strategy matching the current vehicle speed; When it is determined that the current vehicle speed is greater than the second preset vehicle speed threshold, a high-speed control strategy is determined from a predetermined control strategy set as a target control strategy matching the current vehicle speed.

3. The engine start control method of a hybrid vehicle according to claim 1 or 2, characterized in that: The method further comprises: In the process of controlling the clutch to be in the slipping state, determining the real-time resistance torque generated by the clutch on the wheel end of the target vehicle; Obtaining a total remaining torque capacity of the drive motor of the target vehicle and the generator of the target vehicle, wherein the total remaining torque capacity is equal to the sum of the remaining torque capacity of the drive motor of the target vehicle and the remaining torque capacity of the generator of the target vehicle, the remaining torque capacity of the drive motor of the target vehicle is the unused torque of the rated maximum torque of the drive motor of the target vehicle at the current speed, and the remaining torque capacity of the generator of the target vehicle is the unused torque of the rated maximum torque of the generator of the target vehicle at the current speed; The real-time resistance torque is compensated based on the torque compensation capacity of the torque compensation device so that the wheel end outputs a stable torque. The torque compensation device includes a drive motor of the target vehicle and / or a generator of the target vehicle. The torque compensation capacity is less than or equal to the total remaining torque capacity. The stable torque is a torque determined based on the torque output by the wheel of the target vehicle when it is determined that the engine needs to be started.

4. The engine start control method of a hybrid vehicle according to claim 3, characterized in that: Before compensating the real-time resistance torque based on the torque compensation capacity of the torque compensation device so that the wheel end outputs a stable torque, the method further includes: Determining whether the total remaining torque capacity is greater than or equal to a predetermined torque capacity threshold; When it is determined that the total remaining torque capacity is greater than or equal to the torque capacity threshold, triggering the operation of compensating the real-time resistance torque based on the torque compensation capacity of the torque compensation device so that the wheel end outputs a stable torque; When it is determined that the total remaining torque capacity is less than the torque capacity threshold, controlling the drive motor of the target vehicle to operate at a first torque and controlling the generator of the target vehicle to operate at a second torque; Wherein, the first torque is the torque output by the drive motor of the target vehicle when executing the determination of whether the total remaining torque capacity is greater than or equal to a predetermined torque capacity threshold; The second torque is the torque output by the generator of the target vehicle when the determination of whether the total remaining torque capacity is greater than or equal to a predetermined torque capacity threshold is performed; When the current vehicle speed is greater than or equal to the first preset vehicle speed threshold and less than or equal to the second preset vehicle speed threshold, the torque capacity threshold is the first torque capacity threshold; when the current vehicle speed is greater than the second preset vehicle speed threshold, the torque capacity threshold is the second torque capacity threshold.

5. The engine start control method of a hybrid vehicle according to claim 3 or 4, characterized in that: When the current vehicle speed is greater than or equal to the first preset vehicle speed threshold and less than or equal to the second preset vehicle speed threshold, the determining whether the current condition satisfies a predetermined ignition condition corresponding to the ignition device of the engine includes: monitoring the speed of the engine, and when the absolute speed difference between the speed of the engine and a preset speed threshold of the engine is less than or equal to a predetermined speed difference threshold, performing a pressure reduction operation on the clutch, and monitoring the oil pressure of the clutch; When the absolute value of the oil pressure difference between the oil pressure of the clutch and the contact oil pressure of the clutch is less than or equal to a first preset oil pressure difference absolute value, it is determined that the current condition satisfies the predetermined ignition condition corresponding to the ignition device of the engine.

6. The engine start control method of a hybrid vehicle according to any one of claims 1 to 4, characterized in that: When the current vehicle speed is greater than the second preset vehicle speed threshold, the determining whether the current condition satisfies a predetermined ignition condition corresponding to the ignition device of the engine includes: Monitor the oil pressure of the clutch and when the absolute value of the oil pressure difference between the oil pressure of the clutch and the first preset oil pressure threshold of the clutch is less than or equal to the second preset oil pressure difference absolute value, determine that the current condition satisfies the predetermined ignition condition corresponding to the ignition device of the engine.

7. The engine start control method of a hybrid vehicle according to claim 5, characterized in that: The method further comprises: During the process of performing the pressure reduction operation on the clutch, the output torque of the drive motor of the target vehicle and / or the output torque of the generator of the target vehicle is reduced so that the wheel end operates at the stable torque.

8. The engine start control method for a hybrid vehicle according to claim 6, characterized in that: The method further comprises: In the process of controlling the ignition device to ignite to start the engine, controlling the clutch to operate at a target oil pressure, controlling the drive motor of the target vehicle to maintain a third torque, and controlling the generator of the target vehicle to maintain a fourth torque; Wherein, the target oil pressure is the oil pressure corresponding to the clutch when the operation of controlling the ignition device to ignite to start the engine is started; The third torque is the torque output by the drive motor of the target vehicle after the clutch slip ends; the fourth torque is the torque output by the generator of the target vehicle after the clutch slip ends.

9. The engine start control method for a hybrid vehicle according to claim 5, characterized in that: After controlling the engine to start based on the target control strategy, the method further includes: Controlling the oil pressure of the clutch to maintain the contact oil pressure of the clutch, controlling the drive motor of the target vehicle to maintain the reduced output torque, controlling the generator of the target vehicle to maintain the reduced output torque, and determining a first speed output by the generator of the target vehicle; The engine is controlled to operate at a target self-idling speed so that a speed corresponding to the driving disc of the clutch is synchronized with a speed corresponding to the driven disc of the clutch, and the target self-idling speed is equal to the first speed.

10. The engine start control method of a hybrid vehicle according to claim 6, characterized in that: After controlling the engine to start based on the target control strategy, the method further includes: Controlling the oil pressure of the clutch to maintain the oil pressure output by the clutch when the engine is started, controlling the drive motor of the target vehicle to maintain a fifth torque, and controlling the generator of the target vehicle to maintain a sixth torque; Acquire a second speed output by a generator of the target vehicle and a third speed of the engine, and perform PI control on an output torque of the engine according to the second speed and the third speed, so that a speed corresponding to a driving plate of the clutch is synchronized with a speed corresponding to a driven plate of the clutch; Wherein, the fifth torque is the torque output by the drive motor of the target vehicle when the operation of controlling the ignition device to ignite to start the engine is performed; The sixth torque is the torque output by the generator of the target vehicle when the operation of controlling the ignition device to ignite to start the engine is performed.

11. The engine start control method for a hybrid vehicle according to claim 9 or 10, characterized in that: The method further comprises: When the rotation speed corresponding to the active disk is synchronized with the rotation speed corresponding to the driven disk, determining the absolute value of the rotation speed difference between the active disk and the driven disk; When the absolute value of the speed difference is less than or equal to a preset speed difference threshold, a second oil flushing operation is performed on the clutch until the oil pressure of the clutch reaches a preset clamping oil pressure threshold, and the compensation torque of the drive motor of the target vehicle and the compensation torque of the generator of the target vehicle are canceled.

12. An engine start control device for a hybrid vehicle, characterized in that: The device includes an oil flushing module, an acquisition module, a first determination module and a first control module, wherein: The oil flushing module is used to perform an oil flushing operation on the clutch of the target vehicle when it is determined that the engine of the target vehicle needs to be started; The acquisition module is used to acquire the current speed of the target vehicle; The first determination module is used to determine a target control strategy matching the current vehicle speed from a predetermined control strategy set according to the current vehicle speed; The first control module is used to control the engine start based on the target control strategy; The first control module includes a control submodule and a second judgment submodule, wherein: The control submodule is used to control the clutch to be in a slipping state to increase the speed of the engine; The second judgment submodule is used to judge whether the current condition meets the predetermined ignition condition corresponding to the ignition device of the engine; The control submodule is used to control the ignition device to ignite to start the engine when the second judgment submodule judges that the current condition meets the ignition condition; Among them, when the current vehicle speed is greater than or equal to a first preset vehicle speed threshold and less than or equal to a second preset vehicle speed threshold, the current condition is judged by the engine speed and the oil pressure of the clutch; when the current vehicle speed is greater than the second preset vehicle speed threshold, the current condition is judged by the oil pressure of the clutch.

13. The engine start control device for a hybrid vehicle according to claim 12, characterized in that: The first determination module includes a first judgment submodule and a first determination submodule, wherein: The first judgment submodule is used to judge whether the current vehicle speed is greater than or equal to the first preset vehicle speed threshold and less than or equal to the second preset vehicle speed threshold; The first determination submodule is configured to determine a low-speed control strategy from a predetermined control strategy set as a target control strategy matching the current vehicle speed when the first determination submodule determines that the current vehicle speed is greater than or equal to the first preset vehicle speed threshold and less than or equal to the second preset vehicle speed threshold; The first determination submodule is further used to determine a high-speed control strategy from a predetermined control strategy set as a target control strategy matching the current vehicle speed when the first judgment submodule determines that the current vehicle speed is greater than the second preset vehicle speed threshold.

14. The engine start control device for a hybrid vehicle according to claim 12 or 13, characterized in that: The first control module further includes a second determination submodule, an acquisition submodule and a torque compensation submodule, wherein: The second determination submodule is used to determine the real-time resistance torque generated by the clutch on the wheel end of the target vehicle during the process in which the control submodule controls the clutch to be in the slipping state; The acquisition submodule is used to acquire the total remaining torque capacity of the drive motor of the target vehicle and the generator of the target vehicle, wherein the total remaining torque capacity is equal to the sum of the remaining torque capacity of the drive motor of the target vehicle and the remaining torque capacity of the generator of the target vehicle, the remaining torque capacity of the drive motor of the target vehicle is the unused torque of the rated maximum torque of the drive motor of the target vehicle at the current speed, and the remaining torque capacity of the generator of the target vehicle is the unused torque of the rated maximum torque of the generator of the target vehicle at the current speed; The torque compensation submodule is used to compensate the real-time resistance torque based on the torque compensation capacity of the torque compensation device so that the wheel end outputs a stable torque. The torque compensation device includes the drive motor of the target vehicle and / or the generator of the target vehicle. The torque compensation capacity is less than or equal to the total remaining torque capacity. The stable torque is a torque determined based on the torque output by the wheel of the target vehicle when it is determined that the engine needs to be started.

15. The engine start control device for a hybrid vehicle according to claim 14, characterized in that: The second judgment submodule is further configured to judge whether the total remaining torque capacity is greater than or equal to a predetermined torque capacity threshold before the torque compensation submodule compensates the real-time resistance torque based on the torque compensation capacity of the torque compensation device so that the wheel end outputs a stable torque; The torque compensation submodule is specifically used for: When the second judgment submodule determines that the total remaining torque capacity is greater than or equal to the torque capacity threshold, compensating the real-time resistance torque based on the torque compensation capacity of the torque compensation device so that the wheel end outputs a stable torque; The control submodule is further configured to control the drive motor of the target vehicle to operate at a first torque and control the generator of the target vehicle to operate at a second torque when the second judgment submodule determines that the total remaining torque capacity is less than the torque capacity threshold; Wherein, the first torque is the torque output by the drive motor of the target vehicle when executing the determination of whether the total remaining torque capacity is greater than or equal to a predetermined torque capacity threshold; The second torque is the torque output by the generator of the target vehicle when the determination of whether the total remaining torque capacity is greater than or equal to a predetermined torque capacity threshold is performed; When the current vehicle speed is greater than or equal to the first preset vehicle speed threshold and less than or equal to the second preset vehicle speed threshold, the torque capacity threshold is the first torque capacity threshold; when the current vehicle speed is greater than the second preset vehicle speed threshold, the torque capacity threshold is the second torque capacity threshold.

16. The engine start control device for a hybrid vehicle according to claim 15, characterized in that: The second judgment submodule includes a first monitoring unit, a voltage reduction unit and a first determination unit, wherein: The first monitoring unit is used to monitor the engine speed when the current vehicle speed is greater than or equal to the first preset vehicle speed threshold and less than or equal to the second preset vehicle speed threshold; The pressure reduction unit is used to perform a pressure reduction operation on the clutch when the absolute speed difference between the speed of the engine and the preset speed threshold of the engine is less than or equal to a predetermined speed difference threshold; The first monitoring unit is further used to monitor the oil pressure of the clutch; The first determination unit is used to determine that the current condition meets the predetermined ignition condition corresponding to the ignition device of the engine when the absolute value of the oil pressure difference between the oil pressure of the clutch and the contact oil pressure of the clutch is less than or equal to a first preset oil pressure difference absolute value.

17. The engine start control device for a hybrid vehicle according to claim 15, characterized in that: The second judgment submodule includes a second monitoring unit and a second determination unit, wherein: The second monitoring unit is used to monitor the oil pressure of the clutch when the current vehicle speed is greater than the second preset vehicle speed threshold; The second determination unit is used to determine that the current condition satisfies a predetermined ignition condition corresponding to the ignition device of the engine when the absolute value of the oil pressure difference between the oil pressure of the clutch and the first preset oil pressure threshold of the clutch is less than or equal to the second preset oil pressure difference absolute value.

18. The engine start control device for a hybrid vehicle according to claim 16, characterized in that: The first control module further includes a torque reduction submodule, wherein: The torque reduction submodule is used to reduce the output torque of the drive motor of the target vehicle and / or the output torque of the generator of the target vehicle during the process of the second judgment submodule performing the voltage reduction operation on the clutch, so that the wheel end operates at the stable torque.

19. The engine start control device for a hybrid vehicle according to claim 17, characterized in that: The control submodule is further used to control the clutch to operate at a target oil pressure during the process of controlling the ignition device to ignite to start the engine; The control submodule is further used to control the drive motor of the target vehicle to maintain a third torque and control the generator of the target vehicle to maintain a fourth torque; Wherein, the target oil pressure is the oil pressure corresponding to the clutch when the operation of controlling the ignition device to ignite to start the engine is started; The third torque is the torque output by the drive motor of the target vehicle after the clutch slip ends; the fourth torque is the torque output by the generator of the target vehicle after the clutch slip ends.

20. The engine start control device for a hybrid vehicle according to claim 16, characterized in that: The device further includes a first oil pressure maintaining module, a second control module and a second determining module, wherein: The first oil pressure maintaining module is used to maintain the oil pressure of the clutch at the contact oil pressure of the clutch after the first control module controls the engine to start based on the target control strategy; The second control module is used to control the drive motor of the target vehicle to maintain the reduced output torque and control the generator of the target vehicle to maintain the reduced output torque; The second determination module is used to determine a first rotation speed output by a generator of the target vehicle; The second control module is also used to control the engine to operate at a target self-idling speed so that the speed corresponding to the active disk of the clutch is synchronized with the speed corresponding to the driven disk of the clutch, and the target self-idling speed is equal to the first speed.

21. The engine start control device for a hybrid vehicle according to claim 17, characterized in that: The device further includes a second oil pressure maintaining module and a third control module, wherein: The second oil pressure maintaining module is used to maintain the oil pressure of the clutch at the oil pressure output by the clutch when the engine is started after the first control module controls the engine to start based on the target control strategy; The third control module is used to control the drive motor of the target vehicle to maintain a fifth torque and control the generator of the target vehicle to maintain a sixth torque; The acquisition module is further used to acquire a second speed output by the generator of the target vehicle and a third speed of the engine; The third control module is further used to perform PI control on the output torque of the engine according to the second speed and the third speed, so that the speed corresponding to the driving plate of the clutch is synchronized with the speed corresponding to the driven plate of the clutch; Wherein, the fifth torque is the torque output by the drive motor of the target vehicle when the operation of controlling the ignition device to ignite to start the engine is performed; The sixth torque is the torque output by the generator of the target vehicle when the operation of controlling the ignition device to ignite to start the engine is performed.

22. The engine start control device for a hybrid vehicle according to claim 20 or 21, characterized in that: The device further comprises a third determination module and a torque cancellation module, wherein: The third determination module is used to determine the absolute value of the speed difference between the active disk and the driven disk when the speed corresponding to the active disk is synchronized with the speed corresponding to the driven disk; The oil flushing module is further used to perform a second oil flushing operation on the clutch when the absolute value of the speed difference is less than or equal to a preset speed difference threshold, until the oil pressure of the clutch reaches a preset clamping oil pressure threshold; The torque cancellation module is used to cancel the compensation torque of the drive motor of the target vehicle and the compensation torque of the generator of the target vehicle.

23. An engine start control device for a hybrid vehicle, characterized in that: The device comprises: A memory storing executable program code; a processor coupled to the memory; The processor calls the executable program code stored in the memory to execute the engine start control method for a hybrid vehicle as described in any one of claims 1-11.

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