A method, device, vehicle and storage medium for controlling mode switching

Abstract

The present application provides a method, device, vehicle and storage medium for controlling mode switching, which is applied to the field of vehicle technology, and includes: in the process of switching the vehicle from pure electric four-wheel drive mode to direct drive mode, if the target gear is an odd gear, then judging whether the odd gear is available; in the case of determining that the odd gear is not available, judging whether the vehicle meets the preset conditions for switching to the series mode; in the case of determining that the vehicle meets the preset conditions, controlling the engine of the vehicle to be in a running state, and controlling the second clutch to close, so that the vehicle switches from the pure electric four-wheel drive mode to the series mode. The method can ensure the vehicle's power performance, improve the vehicle's driving safety, avoid the vehicle frequently starting the engine, and prohibit the engine from starting after frequently starting the engine, thereby causing the high-voltage battery to be depleted and causing the vehicle to stall, causing safety problems.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and more specifically, to a method, device, vehicle and storage medium for controlling mode switching in the field of vehicles. Background Art

[0002] Hybrid Electric Vehicles (HEV) combine the advantages of engines and electric motors to improve fuel economy, reduce emissions and provide more flexible power output. With the advancement of technology, hybrid vehicles have gradually occupied the market with their unique characteristics.

[0003] Hybrid vehicles include multiple operating modes, such as pure electric rear-wheel drive mode, pure electric four-wheel drive mode, direct drive mode and series mode. During the operation of the vehicle, it will involve switching between several modes to meet the vehicle operation requirements.

[0004] In the prior art, when a vehicle switches from a pure electric four-wheel drive mode to a direct drive mode, the engine may be started multiple times to shift gears so that the vehicle can complete the switch from the pure electric four-wheel drive mode to the direct drive mode. Starting the engine multiple times can easily lead to the problem of frequently starting the engine. Summary of the invention

[0005] The present application provides a method, device, vehicle and storage medium for controlling mode switching, which can ensure the vehicle's power performance, improve the vehicle's driving safety, avoid frequent engine starting of the vehicle, and avoid other problems caused by frequent engine starting.

[0006] In a first aspect, a method for controlling mode switching is provided, which is applied to a hybrid vehicle, the vehicle including a hybrid transmission, the hybrid transmission including: a first input shaft and a second input shaft, the first input shaft being connected to a first clutch, the second input shaft being connected to a second clutch, the first input shaft including an odd gear, the method including: during the process of the vehicle switching from a pure electric four-wheel drive mode to a direct drive mode, if the target gear is an odd gear, determining whether the odd gear is available; wherein, in the pure electric four-wheel drive mode, the first clutch is in an open state, and the second clutch is in an open state; when it is determined that the odd gear is not available, determining whether the vehicle meets a preset condition for switching to a series mode; when it is determined that the vehicle meets the preset condition, controlling the engine of the vehicle to be in a running state, and controlling the second clutch to close, so that the vehicle switches from the pure electric four-wheel drive mode to the series mode.

[0007] In the above technical solution, when the target gear is an odd gear during the process of switching the vehicle from the pure electric four-wheel drive mode to the direct drive mode, the vehicle usually needs to control the first input shaft to be in an odd gear in order to successfully switch from the pure electric four-wheel drive mode to the direct drive mode. If it is determined that the odd gear is unavailable during the mode switching process, it can be determined that the vehicle may have multiple attempts to start the engine and control the first input shaft to be in an odd gear to switch to the direct drive mode during the process of switching the vehicle from the pure electric four-wheel drive mode to the direct drive mode. However, because the odd gear is unavailable, even if multiple attempts are made to start the engine, it is still not possible to switch to the direct drive mode smoothly, resulting in the problem of frequent engine starting of the vehicle, and the vehicle may be prohibited from starting the engine due to multiple engine starts. Therefore, in this case, when it is determined that the odd gear is unavailable, it is directly judged whether the vehicle meets the conditions for switching to the series mode. When the conditions for switching to the series mode are met, the vehicle is controlled to switch from the pure electric four-wheel drive mode to the series mode. Because the vehicle does not need to drive the front wheels in the series mode, even if the odd axle is unavailable, it will not affect the vehicle switching to the series mode. In the series mode, the engine is in running state, and the engine can continue to run, avoiding frequent engine starting and the vehicle being prohibited from starting the engine due to frequent engine starting. In the series mode, the engine can drive the front drive motor to generate electricity and charge the high-voltage battery, ensuring the vehicle's power performance and improving the vehicle's driving safety. It avoids the vehicle running in the pure electric four-wheel drive mode for a long time after the engine is prohibited from starting, resulting in serious depletion of the high-voltage battery, thereby causing safety problems caused by vehicle stalling.

[0008] In combination with the first aspect, in some possible implementations, if the target gear is an odd gear, it is determined whether the odd gear is available, including: if the target gear is an odd gear, the engine is started, the number of times the engine is started is recorded, and the first input shaft is controlled to shift into the odd gear, and if the shifting into the odd gear fails, the engine is controlled to stop; if the number of starts is less than the preset number, the engine is started again, the number of starts is recorded, and the first input shaft is controlled to shift into the odd gear until the number of starts is equal to the preset number; if the number of starts is equal to the preset number, if the shifting into the odd gear still fails, it is determined that the odd gear is unavailable.

[0009] In the above technical solution, when the number of starts is less than the preset number of starts, the engine is started multiple times to control the first input shaft to engage in odd gears, so as to realize multiple attempts to switch from the pure electric four-wheel drive mode to the direct drive mode, thereby reducing the situation where the operation of engaging the first input shaft in odd gears fails during a single attempt to switch the mode, resulting in unsuccessful switching to the direct drive mode, thereby improving the success rate of switching from the pure electric four-wheel drive mode to the direct drive mode. When the number of starts is equal to the preset number of times, if the operation of attempting to engage the first input shaft in odd gears to switch to the direct drive mode still fails, it is finally determined that the odd gear is unavailable, thereby improving the accuracy of judging the availability of the odd gears and reducing the possibility of misjudgment due to a single failure.

[0010] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the method of determining that the engagement of an odd gear has failed includes: determining whether the duration of engagement of an odd gear has been greater than a preset duration; and determining that the engagement of an odd gear has failed when the duration of engagement of an odd gear has been greater than a preset duration and the actual gear position of the first input shaft is neutral.

[0011] In the above technical solution, by comparing the operation time of the first input shaft shifting into the odd gear with the preset time, it is determined whether the operation of controlling the first input shaft to shift into the odd gear is successful. This can effectively eliminate misjudgments caused by temporary problems such as short-term mechanical jamming or electrical interference, and improve the accuracy of detecting failure of the gear shifting operation.

[0012] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, when it is determined that the odd gear is not available, it is judged whether the vehicle meets the preset conditions for switching to the series mode, including: when it is determined that the odd gear is not available, if the target operation mode of the vehicle is determined to be the direct drive mode, the actual operation mode is the pure electric four-wheel drive mode, the first clutch is in the open state, the second clutch is in the open state, the second input shaft is in the even gear, and the first input shaft is in neutral, then it is judged whether the vehicle meets the preset conditions for switching to the series mode.

[0013] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, controlling the second clutch to close includes: controlling the front drive motor of the vehicle to reduce torque; when the actual torque of the front drive motor is less than or equal to the target torque, controlling the second input shaft to disengage gear; and when it is determined that the second input shaft is in neutral, controlling the second clutch to close.

[0014] In the above technical solution, the front-drive motor is controlled to reduce torque and then the second input shaft is controlled to disengage gear, so as to avoid the situation where the front-drive motor is prone to spin due to lack of load after the second input shaft is disengaged. When the second input shaft is in neutral, the second clutch is controlled to close, so as to ensure that the torque output by the engine is only transmitted to the front-drive motor through the second clutch, and no torque is output to the front wheels of the vehicle, thereby ensuring that the vehicle is successfully switched to the series mode.

[0015] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, controlling the front drive motor of the vehicle to reduce torque includes: modifying the target operating mode of the vehicle to a series mode; and when the target operating mode is a series mode, controlling the front drive motor of the vehicle to reduce torque.

[0016] In the above technical solution, during the process of switching from the pure electric four-wheel drive mode to the direct drive mode, after the mode switching fails due to the unavailability of odd gears, when it is determined that the vehicle meets the preset conditions for switching to the series mode, the target operation mode is modified to the series mode. This can clarify the target operation mode that currently needs to be switched, improve the clarity of the vehicle mode switching logic, and enhance the flexibility of the vehicle mode switching.

[0017] In combination with the first aspect and the above-mentioned implementation methods, in certain possible implementation methods, when it is determined that the second input shaft is in neutral, the second clutch is controlled to close, including: when it is determined that the second input shaft is in neutral, the front drive motor is controlled to adjust the speed so that the speed difference between the two ends of the second clutch is less than the preset speed difference; when it is determined that the speed difference between the two ends of the second clutch is less than the preset speed difference, the second clutch is controlled to close.

[0018] In the above technical solution, the speed of the front-drive motor is adjusted to reduce the speed difference at both ends of the second clutch. After determining that the speed difference at both ends of the second clutch is less than the preset speed difference, the second clutch is controlled to close. This ensures that the second clutch closes safely and smoothly, avoids impact or vibration when the second clutch closes, and improves driving comfort and vehicle stability.

[0019] In summary, in the process of switching the vehicle from the pure electric four-wheel drive mode to the direct drive mode, when the target gear is an odd gear, if it is determined that the odd gear is not available, it is directly judged whether the vehicle meets the conditions for switching to the series mode, and the vehicle is controlled to switch from the pure electric four-wheel drive mode to the series mode under the conditions of switching to the series mode. In the series mode, the engine continues to run, avoiding frequent engine starting, and avoiding the vehicle prohibiting the engine from starting due to multiple engine starts. In the series mode, the engine can drive the front drive motor to generate electricity and charge the high-voltage battery, thereby ensuring the power performance of the vehicle and improving the driving safety of the vehicle. In the case of multiple attempts to start the engine and control the first input shaft to switch to the direct drive mode in an odd gear, it is finally determined that the odd gear is not available, which improves the accuracy of judging the availability of the odd gear and reduces the possibility of misjudgment caused by a single failure. Modifying the target operation mode to the series mode can clarify the target operation mode that needs to be switched at present, improve the clarity of the vehicle mode switching logic, and in the process of switching the series mode, the front drive motor is controlled to reduce torque and then the second input shaft is controlled to disengage, thereby avoiding the situation that the front drive motor is prone to flying without load after the second input shaft is disengaged.

[0020] In a second aspect, a device for controlling mode switching is provided, which is applied to a hybrid vehicle, the vehicle including a hybrid transmission, the hybrid transmission including: a first input shaft and a second input shaft, the first input shaft being connected to a first clutch, the second input shaft being connected to a second clutch, the first input shaft including an odd gear, the device including: a first judgment module, for judging whether the odd gear is available when the target gear is an odd gear during the process of the vehicle switching from a pure electric four-wheel drive mode to a direct drive mode; wherein, in the pure electric four-wheel drive mode, the first clutch is in an open state and the second clutch is in an open state; a second judgment module, for judging whether the vehicle meets a preset condition for switching to a series mode when it is determined that the odd gear is not available; a control module, for controlling the engine of the vehicle to be in a running state and controlling the second clutch to close when it is determined that the vehicle meets the preset condition, so as to switch the vehicle from a pure electric four-wheel drive mode to a series mode.

[0021] In combination with the second aspect, in some possible implementations, the first judgment module is specifically used to, if the target gear is an odd gear, start the engine, record the number of times the engine is started, and control the first input shaft to shift into the odd gear; if the shifting into the odd gear fails, control the engine to shut down; if the number of starts is less than the preset number, start the engine again, record the number of times the engine is started, and control the first input shaft to shift into the odd gear until the number of starts is equal to the preset number; if the number of starts is equal to the preset number, if the shifting into the odd gear still fails, it is determined that the odd gear is unavailable.

[0022] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the first judgment module is specifically used to determine whether the time for engaging the odd gear is greater than the preset time; when the time for engaging the odd gear is greater than the preset time and the actual gear position of the first input shaft is neutral, it is determined that engaging the odd gear is unsuccessful.

[0023] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the second judgment module is specifically used to, when it is determined that the odd gear is not available, if the target operation mode of the vehicle is determined to be the direct drive mode, the actual operation mode is the pure electric four-wheel drive mode, the first clutch is in the open state, the second clutch is in the open state, the second input shaft is in the even gear, and the first input shaft is in neutral, then determine whether the vehicle meets the preset conditions for switching to the series mode.

[0024] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the control module is specifically used to control the front drive motor of the vehicle to reduce torque; when the actual torque of the front drive motor is less than or equal to the target torque, control the second input shaft to disengage gear; when it is determined that the second input shaft is in neutral, control the second clutch to close.

[0025] In combination with the second aspect and the above-mentioned implementations, in some possible implementations, the control module is specifically used to modify the target operating mode of the vehicle to the series mode; when the target operating mode is the series mode, control the front drive motor of the vehicle to reduce torque.

[0026] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the control module is specifically used to, when it is determined that the second input shaft is in neutral, control the speed of the front-drive motor so that the speed difference at both ends of the second clutch is less than the preset speed difference; when it is determined that the speed difference at both ends of the second clutch is less than the preset speed difference, control the second clutch to close.

[0027] In a third aspect, a vehicle is provided, comprising a memory and a processor. The memory is used to store executable program code, and the processor is used to call and run the executable program code from the memory, so that the vehicle executes the method in the first aspect or any possible implementation of the first aspect.

[0028] In a fourth aspect, a computer program product is provided, comprising: a computer program code, which, when executed on a computer, enables the computer to execute the method in the first aspect or any possible implementation of the first aspect.

[0029] In a fifth aspect, a computer-readable storage medium is provided, which stores a computer program code. When the computer program code runs on a computer, the computer executes the method in the above-mentioned first aspect or any possible implementation manner of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the architecture of a hybrid vehicle provided in an embodiment of the present application.

[0031] Figure 2 It is a flowchart of a method for controlling mode switching provided in an embodiment of the present application.

[0032] Figure 3 It is a structural schematic diagram of a control mode switching device provided in an embodiment of the present application.

[0033] Figure 4 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0035] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0036] Figure 1 It is a schematic diagram of the architecture of a hybrid vehicle provided in an embodiment of the present application.

[0037] For example, Figure 1 As shown, the hybrid vehicle includes: a first motor 101 , a first motor controller 102 , a hybrid transmission 103 , an engine 104 , a high-voltage battery 105 , a second motor 106 , front wheels 107 , rear wheels 108 and a differential 109 .

[0038] The first motor 101 is also called a front drive motor or a P2.5 motor. The first motor 101 drives the front wheels 107 of the vehicle through the hybrid transmission 103 or works as a generator.

[0039] The first motor controller 102 is used to control the speed, torque and direction of the first motor 101. Specifically, by adjusting the current and voltage of the first motor 101, the speed of the first motor 101 is accurately controlled to ensure that the first motor 101 operates within the optimal speed range under different working conditions. According to the needs of the vehicle, the output torque of the first motor 101 is accurately controlled to ensure that the vehicle obtains sufficient driving force under acceleration, climbing, etc. By controlling the rotation direction of the first motor 101, it is ensured that the first motor 101 can rotate forward or reverse when needed.

[0040] The hybrid transmission 103 is a 4-speed transmission, including 4 forward gears, namely 1st gear, 2nd gear, 3rd gear and 4th gear. The hybrid transmission specifically includes: a K1 clutch 1031 , a K2 clutch 1032 , a first input shaft 1033 , a second input shaft 1034 , a first synchronizer 1035 , and a second synchronizer 1036 .

[0041] The K1 clutch 1031 and the K2 clutch 1032 are used to connect or disconnect the mechanical connection between the engine 104 and the input shaft of the hybrid transmission 103, and the input shaft of the hybrid transmission is the first input shaft 1033 and the second input shaft 1034. Specifically, the K1 clutch 1031 is connected to the first input shaft 1033. When the K1 clutch 1031 is in an open state, the engine 104 and the first input shaft 1033 are disconnected. When the K1 clutch 1031 is in a closed state, the engine 104 and the first input shaft 1033 are connected. The K2 clutch 1032 is connected to the second input shaft 1034. When the K2 clutch 1032 is in an open state, the engine 104 and the second input shaft 1034 are disconnected. When the K2 clutch 1032 is in a closed state, the engine 104 and the second input shaft 1034 are connected.

[0042] The first input shaft 1033 is also called an odd-numbered shaft, including odd-numbered gears: 1st gear and 3rd gear. The first synchronizer 1035 is used to select the 1st gear or 3rd gear on the first input shaft 1033, so that the engine 104 transmits the power corresponding to the 1st gear or 3rd gear. The second input shaft 1034 is also called an even-numbered shaft, including even-numbered gears: 2nd gear and 4th gear. The second synchronizer 1036 is used to select the 2nd gear or 4th gear on the second input shaft 1034, so that the engine 104 transmits the power corresponding to the 2nd gear or 4th gear.

[0043] The first motor 101 is also connected to the second input shaft 1034 of the hybrid transmission 103 , and the K2 clutch 1032 is also used to connect or disconnect the engine 104 from the first motor 101 .

[0044] The engine 104 is one of the power sources of the vehicle, and generates power by burning fuel (such as gasoline or diesel). The power generated by the engine 104 is transmitted to the hybrid transmission 103 through the clutch, and finally drives the front wheels 107 of the vehicle.

[0045] The high-voltage battery 105 is used to supply power to the second motor 106 and the first motor 101 , so that the second motor 106 and the first motor 101 output torque to drive the vehicle.

[0046] The second motor 106 is a rear-drive motor or a P4 motor. When the second motor 106 is running, it transmits power to the rear wheels 108 of the vehicle to drive the vehicle.

[0047] The differential 109 is used to allow the left and right wheels to rotate at different speeds when the vehicle turns. Through the differential 109, the outer wheels can rotate at a faster speed, and the inner wheels can rotate at a slower speed, ensuring that the vehicle turns smoothly.

[0048] In the pure electric four-wheel drive mode, the engine 104 is in a stopped state, the first motor 101 is in a running state, the K1 clutch 1031 and the K2 clutch 1032 are both in an open state, the first input shaft 1033 is in 1st gear or 3rd gear, and the second input shaft 1034 is in 2nd gear or 4th gear. The first motor 101 transmits power to the front wheels 107 of the vehicle through the second input shaft 1034, and the second motor 106 is in a running state, transmitting power to the rear wheels 108 of the vehicle to drive the vehicle.

[0049] In direct drive mode, the engine 104 and the motor drive the vehicle together. Specifically, the second motor 106 and the engine 104 are both in a driving state, the second motor 106 is used to drive the rear wheels 108, and the engine 104 is used to drive the front wheels 107. The state of the first motor 101 is related to the current vehicle speed, which is described below:

[0050] In direct drive mode, if the current vehicle speed is less than or equal to the creeping speed, the first motor 101 is in a non-operating state. The non-operating state can be understood as a 0 torque state, that is, the first motor 101 does not output torque. In the non-operating state, the first motor 101 neither participates in the driving of the front wheels 107 nor charges the high-voltage battery 105. In direct drive mode, if the current vehicle speed is greater than the creeping speed, the first motor 101 is in a power generation state or a driving state. When the first motor 101 is in a power generation state, the first motor 101 is used to charge the high-voltage battery 105. When the first motor 101 is in a driving state, the engine 104 and the first motor 101 are used to drive the front wheels 107 together.

[0051] Specifically, the output torque of the engine 104 may be compared with the required torque of the front wheels 107 to determine whether the first motor 101 is in a power generation state or a driving state.

[0052] If the output torque of the engine 104 is greater than the required torque of the front wheels 107, it means that the output torque of the engine 104 can not only meet the required torque of the front wheels 107 but also has excess torque. At this time, the output torque of the engine 104 can be divided into driving torque and charging torque. The driving torque is equal to the required torque of the front wheels, and the driving torque is used to drive the front wheels 107. The charging torque is equal to the torque difference between the output torque of the engine 104 and the driving torque, that is, the excess torque. The charging torque is used to provide to the first motor 101, so that the high-voltage battery 105 can be charged through the first motor 101. At this time, the first motor 101 is in a power generation state.

[0053] If the output torque of the engine 104 is less than the required torque of the front wheels 107, it means that the output torque of the engine 104 cannot meet the required torque of the front wheels 107, and the first motor 101 needs to assist. At this time, the torque difference between the required torque of the front wheels 107 and the output torque of the engine 104 can be determined as the assist torque of the first motor 101 so that the first motor 101 drives the front wheels 107 together with the engine 104 by outputting the assist torque. At this time, the first motor 101 is in a driving state.

[0054] If the output torque of the engine 104 is equal to the required torque of the front wheels 107, it means that the output torque of the engine 104 can just meet the required torque of the front wheels 107. At this time, the first motor 104 does not need to assist or generate electricity, that is, the first motor 101 can be in a non-working state.

[0055] In the series mode, the engine 104 is in operation, the engine 104 drives the first motor 101 to operate and generate electricity, the second motor 106 is in operation, and transmits power to the rear wheels 108 of the vehicle to drive the vehicle, and the front wheels 107 of the vehicle are in a driven state. In the series mode, the electric energy generated by the operation of the first motor 101 can be transmitted to the high-voltage battery 105 to charge the high-voltage battery 105.

[0056] In the prior art, Figure 1 When a hybrid vehicle of the shown architecture switches from pure electric four-wheel drive mode to direct drive mode, the vehicle may fail to switch to direct drive mode due to failure to shift gears, etc. At this time, the vehicle will start the engine multiple times to try to switch from pure electric four-wheel drive mode to direct drive mode. Starting the engine multiple times can easily cause the problem of frequently starting the engine.

[0057] Furthermore, the inventor of the present application has found through research that since starting the engine multiple times can easily affect the user's driving experience, a maximum number of times the engine can be started can be set in the vehicle. When the number of times the engine is started multiple times is equal to the maximum number, if the vehicle still fails to successfully switch from the pure electric four-wheel drive mode to the direct drive mode, the vehicle will prohibit starting the engine to avoid the vehicle's uncontrolled attempts to switch from the series mode to the direct drive mode, ensuring the user's driving experience. At this time, the vehicle will remain in the pure electric four-wheel drive mode. However, if the vehicle is prohibited from starting the engine and runs in the pure electric four-wheel drive mode for a long time, it is easy to cause a serious loss of power in the high-voltage battery, thereby causing the vehicle to stall and affect the driving safety of the vehicle.

[0058] Based on this, the present application proposes a method for switching control modes. During the process of switching the vehicle from pure electric mode to direct drive mode, when it is determined that the odd gear engaged by the first input shaft is unavailable, the vehicle is controlled to switch from pure electric four-wheel drive mode to series mode under the conditions for switching to series mode. This avoids the problem of frequent engine starting and the engine being prohibited from starting. It further avoids the problem of the vehicle running in pure electric four-wheel drive mode for a long time after the engine is prohibited from starting, resulting in serious depletion of the high-voltage battery, thereby causing the vehicle to stall, thereby improving the driving safety of the vehicle.

[0059] Figure 2 is a flow chart of a method for controlling mode switching provided in an embodiment of the present application. The method is applied to include Figure 1 The vehicle includes a hybrid transmission 103, which includes a first input shaft 1033 and a second input shaft 1034, wherein the first input shaft 1033 is connected to a first clutch, and the second input shaft is connected to a second clutch. Figure 1 The K1 clutch 1031 in the second clutch is Figure 1 K2 clutch 1032 in.

[0060] For example, Figure 2 As shown, the method 200 includes:

[0061] Step 201, when the vehicle switches from the pure electric four-wheel drive mode to the direct drive mode, if the target gear is an odd gear, determine whether the odd gear is available; wherein, in the pure electric four-wheel drive mode, the first clutch is in an open state, and the second clutch is in an open state;

[0062] Step 202, when it is determined that the odd gear is unavailable, determining whether the vehicle meets the preset conditions for switching to the series mode;

[0063] Step 203, when it is determined that the vehicle meets the preset conditions, the engine of the vehicle is controlled to be in a running state, and the second clutch is controlled to be closed, so that the vehicle switches from the pure electric four-wheel drive mode to the series mode.

[0064] exist Figure 2In the illustrated embodiment, when the vehicle switches from the pure electric four-wheel drive mode to the direct drive mode, when the target gear is an odd gear, the vehicle usually needs to control the first input shaft to be in an odd gear in order to successfully switch from the pure electric four-wheel drive mode to the direct drive mode. If it is determined that the odd gear on the first input shaft is unavailable during the mode switching process, it can be determined that the vehicle may have multiple attempts to start the engine and control the first input shaft to be in an odd gear to switch to the direct drive mode during the process of switching from the pure electric four-wheel drive mode to the direct drive mode. However, because the odd gear is unavailable, even if the engine is tried multiple times, it cannot be switched to the direct drive mode smoothly, resulting in the problem of frequent engine starting of the vehicle, and the vehicle may be prohibited from starting the engine due to multiple engine starts. Therefore, in this case, when it is determined that the odd gear is unavailable and the engine is in the started state, it is directly judged whether the vehicle meets the conditions for switching to the series mode. When the conditions for switching to the series mode are met, the vehicle is controlled to switch from the pure electric four-wheel drive mode to the series mode. Because the vehicle does not need to drive the front wheels in the series mode, even if the odd axle is unavailable, it will not affect the vehicle switching to the series mode. In the series mode, the engine is in the running state, and the engine can continue to run, avoiding frequent engine starting and the vehicle being prohibited from starting the engine due to multiple engine starts. In the series mode, the engine can drive the front drive motor to generate electricity and charge the high-voltage battery, ensuring the vehicle's power performance and improving the vehicle's driving safety. It avoids the vehicle running in the pure electric four-wheel drive mode for a long time after the engine is prohibited from starting, resulting in serious depletion of the high-voltage battery, thereby causing safety problems caused by vehicle stalling.

[0065] Below Figure 2 The specific implementation of each step in the embodiment shown is described in detail:

[0066] In step 201 , when the actual operation mode of the vehicle is the pure electric four-wheel drive mode and the target operation mode is the direct drive mode, the vehicle starts to control the operation mode to switch from the pure electric four-wheel drive mode to the direct drive mode.

[0067] The target gear is the gear at which the vehicle actually outputs power after switching to direct drive mode. The odd gear is the gear on the first input shaft, and the odd gears include 1st gear and 3rd gear. When the target gear is an odd gear, the first input shaft needs to be controlled to be in an odd gear during the process of switching from pure electric four-wheel drive mode to direct drive mode.

[0068] The odd gear may be damaged, causing the odd gear to be unavailable. For example, the vehicle may have an abnormal signal transmitted by the speed sensor of the first input shaft, resulting in an abnormal speed value of the first input shaft. At this time, the vehicle cannot determine the speed difference between the two ends of the first synchronizer of the first input shaft, and cannot perform the gear shifting action, resulting in the odd gear being unavailable. Therefore, when switching from pure electric four-wheel drive mode to direct drive mode, if the target gear is an odd gear, it is necessary to determine whether the odd gear on the first input shaft is available.

[0069] It is understandable that when the vehicle switches from the pure electric four-wheel drive mode to the direct drive mode, if the target gear is an odd gear, the vehicle usually needs to control the first input shaft to be in an odd gear to successfully switch from the pure electric four-wheel drive mode to the direct drive mode. If the odd gear is not available, it can be determined that the vehicle cannot switch from the pure electric four-wheel drive mode to the direct drive mode.

[0070] The user can send a switching instruction to the vehicle to switch to the direct drive mode in the pure electric four-wheel drive mode. When the vehicle receives the above switching instruction, it determines that the vehicle needs to switch from the pure electric four-wheel drive mode to the direct drive mode.

[0071] In some embodiments, the vehicle may also automatically trigger mode switching in certain scenarios. For example, the vehicle may automatically trigger switching from pure electric four-wheel drive mode to direct drive mode in scenarios where greater power output is required in pure electric four-wheel drive mode, such as when the vehicle speed is greater than a preset speed or the depth of the accelerator pedal is greater than a preset depth, or when the power of the high-voltage battery is lower than a preset threshold.

[0072] In one possible implementation, if the target gear is an odd gear, it is determined whether the odd gear is available, including: if the target gear is an odd gear, the engine is started, the number of times the engine is started is recorded, and the first input shaft is controlled to be engaged in the odd gear, and if the engagement in the odd gear fails, the engine is controlled to be shut down; if the number of starts is less than a preset number, the engine is started again, the number of starts is recorded, and the first input shaft is controlled to be engaged in the odd gear until the number of starts is equal to the preset number; if the number of starts is equal to the preset number, and if the engagement in the odd gear still fails, it is determined that the odd gear is unavailable.

[0073] It is understandable that the engine is in a stopped state in pure electric four-wheel drive mode and in a running state in direct drive mode. Therefore, the engine needs to be started in the process of switching from pure electric four-wheel drive mode to direct drive mode. After starting the engine, the first input shaft can be controlled to shift into an odd gear.

[0074] The steps of starting the engine include: controlling the second clutch to be in a slipping state, so that the front drive motor of the vehicle drives the engine to rotate through the slipping second clutch, monitoring the actual speed of the engine during the engine rotation, and when it is determined that the actual speed of the engine is greater than or equal to the preset speed, controlling the engine ignition to start the engine, and after the ignition is successful, controlling the second clutch to be in an open state.

[0075] The preset speed is the minimum speed at which the engine can be ignited and started, for example, 900 rpm, to ensure that the engine can be stably ignited. When it is determined that the actual speed of the engine is greater than or equal to the preset speed, it can be determined that the engine meets the conditions for stable ignition. At this time, the ignition system that controls the engine starts to work, ignites the mixed gas in the engine cylinder, and puts the engine into a self-sustaining operation state to start the engine.

[0076] It is understandable that one end of the second clutch is connected to the engine and the other end is connected to the front drive motor. In the pure electric four-wheel drive mode, the second clutch is in the open state, and the front drive motor is in the running state to output power to the front wheels of the vehicle through the second input shaft. After controlling the second clutch to be in the slipping state, the front drive motor in the running state can drive the engine to rotate through the slipping second clutch. The target gear is an odd gear, that is, after the vehicle switches to the direct drive mode, the engine outputs power through the odd gear of the first input shaft. The switched direct drive mode requires the first clutch to be closed and the second clutch to be opened. Therefore, after starting the engine, it is necessary to control the second clutch to open from the slipping state.

[0077] In the case that the first input shaft fails to shift into the odd gear, it can be determined that the current operation of starting the engine and switching to the direct drive mode has failed, and the engine is controlled to stop.

[0078] When the engine is started, the number of times the engine is started can be recorded to obtain the number of starts. Each time the engine is started, the number of starts is increased by 1. The preset number is the maximum number of times the engine is allowed to start continuously set in advance. After the number of engine starts equals the preset number, if the engine is shut down, the engine will be prohibited from starting.

[0079] If the recorded number of starts is less than the preset number, the engine can be started again to record the number of starts, and after the engine is started, the first input shaft is controlled to be engaged in an odd gear. If the first input shaft is still unsuccessful in engaging in an odd gear, it is determined that the current operation of starting the engine and switching to the direct drive mode has failed, and the engine is controlled to stop again. If the number of starts is less than the preset number, the above steps are executed repeatedly until the number of starts is equal to the preset number.

[0080] When the number of starts is equal to the preset number of times, it is determined whether the operation of controlling the first input shaft to shift into the odd gear after the current engine start is successful. If it is determined that the operation of controlling the first input shaft to shift into the odd gear after the current engine start still fails, it is determined that the odd gear on the first input shaft is unavailable.

[0081] It is understandable that when the vehicle meets the conditions for switching from the pure electric four-wheel drive mode to the direct drive mode, after the engine startup fails to switch to the direct drive mode and the engine is controlled to stop, the vehicle usually starts the engine continuously and controls the first input shaft to shift to an odd gear. Therefore, in some embodiments, it can be determined whether the number of engine startups recorded within a preset time is equal to the preset number, so as to determine whether the number of engine startups is equal to the preset number because the vehicle needs to switch to the direct drive mode.

[0082] In some embodiments, Figure 1 The control unit in the hybrid vehicle shown may include: a hybrid transmission controller (Transmission Control Unit, TCU), a vehicle controller (Hybrid Control Unit, HCU), an EMS (Engine Management System), and a FMCU (Front Motor Control Unit). The execution subject of the control method may be a control unit in the vehicle, such as the above-mentioned HCU or TCU or EMS or FMCU.

[0083] Specifically, when it is determined that the target operation mode of the vehicle is the direct drive mode, the actual operation mode is the pure electric four-wheel drive mode, the second clutch is in the open state, the engine is in the start state, the first clutch is in the open state, the second synchronizer on the second input shaft is in the even gear, the first synchronizer on the first input shaft is in the neutral gear, the target gear is the odd gear, and the first input shaft fails to be in the odd gear, the HCU controls the engine to stop, and after the engine is stopped, the engine is started again to control the first input shaft to be in the odd gear, so that the vehicle switches to the direct drive mode. Among them, the even gear includes the 2nd gear and the 4th gear.

[0084] During the process of switching the vehicle from the pure electric mode to the direct drive mode, the number of engine starts recorded each time the engine is started is increased by 1. If the number of starts recorded within the preset time is equal to the preset number, for example, four times, then it is determined whether the fourth operation of controlling the first input shaft to shift to an odd gear is successful after the fourth engine start. If it is determined that the fourth operation of controlling the first input shaft to shift to an odd gear fails, the TCU sends a signal that the odd gear is unavailable to the HCU, and controls the first synchronizer of the first input shaft to shift to neutral.

[0085] In the above method, when the number of starts is less than the preset number of starts, the engine is started multiple times to control the first input shaft to engage in odd gears, so as to realize multiple attempts to switch from the pure electric four-wheel drive mode to the direct drive mode, thereby reducing the situation where the operation of engaging the first input shaft in odd gears fails during a single attempt to switch the mode, resulting in unsuccessful switching to the direct drive mode, thereby improving the success rate of switching from the pure electric four-wheel drive mode to the direct drive mode. When the number of starts is equal to the preset number of times, if the operation of attempting to engage the first input shaft in odd gears to switch to the direct drive mode still fails, it is finally determined that the odd gear is unavailable, thereby improving the accuracy of judging the availability of the odd gears and reducing the possibility of misjudgment due to a single failure.

[0086] In one possible implementation, the method for determining that the engagement of an odd gear has failed includes: determining whether the duration of the engagement of an odd gear has been greater than a preset duration; and determining that the engagement of an odd gear has failed when the duration of the engagement of an odd gear has been greater than a preset duration and the actual gear position of the first input shaft is neutral.

[0087] The preset time length is a time threshold set in advance, and specifically may be the maximum time length required for the first input shaft to complete the gear shifting. The preset time length is used to determine whether the gear shifting operation is completed.

[0088] Each time the vehicle starts the engine, the first input shaft will be controlled to shift into the odd gear. At this time, the time for controlling the first input shaft to shift into the odd gear can be obtained and compared with the preset time. After the time for shifting into the odd gear is greater than the preset time, the actual gear position of the first input shaft is obtained. If the actual gear position of the first input shaft is still neutral, it can be determined that the shifting into the odd gear was unsuccessful.

[0089] In some embodiments, after determining that the vehicle starts the engine, the HCU may send a control instruction to the TCU to control the first input shaft to engage in an odd gear, so that the TCU starts to control the first input shaft to engage in an odd gear after receiving the control instruction. The step of obtaining the duration of controlling the first input shaft to engage in an odd gear may include: starting timing when the TCU receives the above control instruction, and using the timing duration as the duration of engaging in an odd gear. When the TCU successfully engages in an odd gear, the TCU may also feedback a signal of successful gear engagement, and may end the timing after the TCU feedbacks a signal of successful gear engagement. When the TCU does not feedback a signal of successful gear engagement, the timing may continue until the timing duration is greater than a preset duration.

[0090] Specifically, the odd gear includes the 1st gear or the 3rd gear, and controlling the first input shaft to be engaged in the odd gear means controlling the first input shaft to be engaged in the 1st gear or the 3rd gear. When the time duration of controlling the first input shaft to be engaged in the 1st gear or the 3rd gear exceeds the maximum time duration required to complete the gear engagement, i.e., the preset time duration, and the gear position of the first input shaft is still neutral, it can be determined that the operation of controlling the first input shaft to be engaged in the odd gear is unsuccessful.

[0091] It can be understood that when the number of engine starts is equal to the preset number of times, the duration of controlling the first input shaft to shift into the odd gear after the engine is started can also be recorded, that is, the operation duration of the first synchronizer shifting gear can be recorded. When the actual gear position of the first input shaft is still neutral after the operation duration is greater than the preset duration, it can be determined that the operation of controlling the first input shaft to shift into the odd gear corresponding to the number of starts is unsuccessful, and at this time it can be determined that the odd gear is unavailable.

[0092] Exemplarily, the preset number of times is 4 times, and the step of determining that the odd gear is unavailable specifically includes: starting the engine for the first time, recording the number of starts as 1. After starting the engine, controlling the first input shaft to engage in an odd gear, if the first input shaft is still in neutral after the time length of engaging in the odd gear is greater than the preset time length, determining that the gear engagement has failed, and controlling the engine to stop. The number of starts is 1 time, which is less than the preset number of times 4 times, and the engine is started again after the engine is stopped, and the number of starts is increased by 1 time to become 2 times. After starting the engine, controlling the first input shaft to engage in an odd gear, if the first input shaft is still in neutral after the time length of engaging in the odd gear is greater than the preset time length, determining that the gear engagement has failed, and controlling the engine to stop. The number of starts is 2 times, which is less than the preset number of times 4 times, and the engine is started again after the engine is stopped, and the number of starts is increased by 1 time to become 3 times. After starting the engine, controlling the first input shaft to engage in an odd gear, if the first input shaft is still in neutral after the time length of engaging in the odd gear is greater than the preset time length, determining that the gear engagement has failed, and controlling the engine to stop. The number of starts is 3 times, which is less than the preset number of times, 4 times. After the engine is shut down, the engine is started again, and the number of starts is increased by 1 to become 4 times. At this time, the number of starts is equal to the preset number of starts. After the engine is started, the first input shaft is controlled to be engaged in an odd gear. When the first input shaft is still in neutral after the odd gear is engaged for a time longer than the preset time, it is determined that the odd gear is unavailable.

[0093] In the above method, by comparing the operation time of the first input shaft shifting into the odd gear with the preset time, it is determined whether the operation of controlling the first input shaft to shift into the odd gear is successful. This can effectively eliminate misjudgments caused by temporary problems such as short-term mechanical jamming or electrical interference, and improve the accuracy of detecting failure of the gear shifting operation.

[0094] In step 202, after determining that the odd gear of the first input shaft is unavailable, the current state of the engine can be obtained. If it is determined that the current state of the engine is the start state, it indicates that the current engine has not been prohibited from starting, and the vehicle can also switch to the series mode to avoid being prohibited from starting after the engine is stopped. At this time, it can be determined whether the vehicle meets the preset conditions for switching to the series mode.

[0095] It is understandable that the vehicle controls the first input shaft to shift into an odd gear after starting the engine. When the first input shaft fails to shift into an odd gear, the engine is still in the starting state.

[0096] The preset conditions may include that the remaining power of the high-voltage battery is less than a preset power (eg, 20%) and / or the vehicle's total vehicle torque requirement is less than a preset torque.

[0097] In some embodiments, when the number of starts is less than the preset number, it is also possible to determine whether the vehicle meets the preset conditions for switching to the series mode each time the operation of starting the engine to control the first input shaft to shift into an odd gear fails, so that the vehicle can switch to the series mode in advance. Since the number of engine starts is less than the preset number at this time, the engine will not be prohibited from starting after shutdown, so the engine does not need to be in the started state at this time. Starting the engine during the process of switching to the series mode can avoid the engine being prohibited from starting.

[0098] In one possible implementation, when it is determined that odd gears are not available, it is determined whether the vehicle meets the preset conditions for switching to the series mode, including: when it is determined that odd gears are not available, if the target operating mode of the vehicle is determined to be the direct drive mode, the actual operating mode is the pure electric four-wheel drive mode, the first clutch is in the open state, the second clutch is in the open state, the second input shaft is in the even gear, and the first input shaft is in neutral, then it is determined whether the vehicle meets the preset conditions for switching to the series mode.

[0099] When it is determined that the odd gears on the first input shaft are unavailable, the vehicle's target operating mode, actual operating mode, state of the first clutch, state of the second clutch, gear position of the second input shaft, and gear position of the first input shaft can be obtained.

[0100] When it is determined that the target operating mode of the vehicle is the direct drive mode, the actual operating mode is the pure electric four-wheel drive mode, the first clutch is in the open state, the second clutch is in the open state, the second input shaft is in an even gear, and the first input shaft is in neutral, it is determined whether the vehicle meets the preset conditions for switching to the series mode.

[0101] It can be understood that, according to the vehicle's actual operating mode being pure electric four-wheel drive mode and the target operating mode being direct drive mode, it can be determined again that the multiple engine starts are for switching to direct drive mode. Since the second input shaft is in an even gear in the series mode, the first clutch and the second clutch are both in an open state. The first input shaft fails to be engaged in an odd gear, so the first input shaft is in neutral gear. Therefore, based on the state of the first clutch, the state of the second clutch, the gear engaged by the second input shaft, and the gear engaged by the first input shaft, it can be further determined that the vehicle's actual operating mode is the series mode.

[0102] In step 203, after determining that the vehicle meets the preset conditions for switching to the series mode, if the engine is in the starting state, the engine is controlled to maintain the running state. If the engine is not started, the engine is controlled to start and the engine is controlled to maintain the running state. After that, the second clutch is controlled to close. The vehicle can complete the switch from the pure electric four-wheel drive mode to the series mode.

[0103] It is understandable that when it is determined in the above scheme that the odd gears on the first input shaft are unavailable, it can be determined that the vehicle cannot switch from pure electric four-wheel drive mode to direct drive mode, and the vehicle is still in pure electric four-wheel drive mode. If the engine is shut down at this time, the engine will be prohibited from starting, and the vehicle will be prohibited from running in pure electric mode for a long time after the engine is started, and the high-voltage battery will run out of power, causing the vehicle to stall. If the vehicle meets the preset conditions for switching to series mode at this time, the vehicle can be controlled to switch from pure electric four-wheel drive mode to series mode. If the engine is in operation in series mode, the engine does not need to be shut down, and the engine will not be prohibited from starting.

[0104] In one possible implementation, controlling the second clutch to close includes: controlling the front drive motor of the vehicle to reduce torque; controlling the second input shaft to disengage when the actual torque of the front drive motor is less than or equal to the target torque; and controlling the second clutch to close when it is determined that the second input shaft is in neutral.

[0105] In pure electric four-wheel drive mode, the first input shaft is in neutral gear, the second input shaft is in even gear, and the front-drive motor outputs a certain torque. The torque output by the front-drive motor is transmitted to the front wheels of the vehicle through the even gear of the second input shaft to drive the vehicle. In series mode, both the first input shaft and the second input shaft are in neutral gear. Therefore, after determining that the vehicle meets the preset conditions for switching to series mode, it is necessary to control the second input shaft to disengage gear.

[0106] It is understandable that the second input shaft is used to connect or disconnect the front-drive motor and the front wheels of the vehicle. Specifically, when the second input shaft is in an even gear, the front-drive motor is connected to the front wheels of the vehicle, and when the second input shaft is out of gear, the front-drive motor is disconnected from the wheels of the vehicle.

[0107] In pure electric four-wheel drive mode, the front-drive motor outputs a certain torque. If the second input shaft is directly controlled to disengage, the front-drive motor and the vehicle's wheels will be disconnected and the front-drive motor will be prone to spin without load. Therefore, before controlling the second input shaft to disengage, the front-drive motor needs to be controlled to reduce torque.

[0108] The target torque is the torque at which the front drive motor will not spin wildly, usually 0 NM (Newton meter). After determining that the actual torque of the front drive motor is equal to 0 NM, the second input shaft can be controlled to shift gears. After the second input shaft shifts gears, the actual gear position of the second input shaft is neutral.

[0109] In this solution, in the pure electric four-wheel drive mode after attempting to switch to the direct drive mode, the vehicle's engine is in the starting state, the first clutch is in the open state, and the second clutch is in the open state. In the series mode, the engine is in the starting state, the first clutch is in the open state, and the second clutch is in the closed state. Therefore, after controlling the second input shaft to disengage, it is also necessary to control the second clutch to close so that the vehicle can switch from the pure electric four-wheel drive mode to the series mode. Since the pure electric four-wheel drive mode has attempted to switch to the direct drive mode, the engine is in the starting state. When it is determined that the vehicle meets the preset conditions, the engine is directly controlled to maintain the running state, the second input shaft is controlled to disengage, and the second clutch is controlled to close, so that the switch to the series mode can be achieved. The engine is reasonably used in the starting state, and the efficiency of the vehicle switching from the pure electric four-wheel drive mode to the series mode is improved.

[0110] In the above method, the front-drive motor is controlled to reduce torque and then the second input shaft is controlled to disengage gear, so as to avoid the situation where the front-drive motor is prone to spinning due to lack of load after the second input shaft is disengaged. When the second input shaft is in neutral, the second clutch is controlled to close, so as to ensure that the torque output by the engine is only transmitted to the front-drive motor through the second clutch, and no torque is output to the front wheels of the vehicle, so as to ensure that the vehicle is successfully switched to the series mode.

[0111] In a possible implementation, controlling the front drive motor of the vehicle to reduce torque includes: modifying a target operating mode of the vehicle to a series mode; and controlling the front drive motor of the vehicle to reduce torque when the target operating mode is the series mode.

[0112] When the vehicle meets the preset conditions for switching to the series mode, it can be determined that the target operating mode to be switched by the vehicle is the series mode. At this time, the target operating mode of the vehicle needs to be changed from the direct drive mode to the series mode. After the target operating mode of the vehicle is changed to the series mode, the front drive motor of the vehicle can be controlled to reduce torque.

[0113] Specifically, when it is determined that the vehicle meets the preset conditions, the HCU corrects the target operation mode to the series mode, and sends the target operation mode to the TCU as the series mode. The HCU also sends a signal that the target gear position of the even-numbered axle is neutral to the TCU. At the same time, the HCU controls the front drive motor to reduce the torque to the target torque.

[0114] If the vehicle's actual operating mode is pure electric four-wheel drive mode, the second clutch is in the open state, the engine is in the started state, the first clutch is in the open state, the second input shaft is in the even gear, the first input shaft is in the neutral gear, the target gear is the odd gear and the odd gear is not available, the TCU receives a signal that the target operating mode is the series mode and the target gear of the even shaft is in the neutral gear and determines that the actual torque of the front drive motor is 0Nm, and the TCU controls the even shaft (i.e., the second input shaft) to shift gears to the neutral gear.

[0115] In the above method, during the process of switching from the pure electric four-wheel drive mode to the direct drive mode, after the mode switching fails due to the unavailability of odd gears, when it is determined that the vehicle meets the preset conditions for switching to the series mode, the target operating mode is modified to the series mode. This can clarify the target operating mode that currently needs to be switched, improve the clarity of the vehicle mode switching logic, and enhance the flexibility of the vehicle mode switching.

[0116] In one possible implementation, when it is determined that the second input shaft is in neutral, the second clutch is controlled to close, including: when it is determined that the second input shaft is in neutral, controlling the speed of the front drive motor so that the speed difference between the two ends of the second clutch is less than a preset speed difference; when it is determined that the speed difference between the two ends of the second clutch is less than the preset speed difference, controlling the second clutch to close.

[0117] It is understandable that controlling the closing of the second clutch requires that the speed difference between the two ends of the second clutch is less than a certain value to ensure safe closing of the second clutch. The preset speed difference is the maximum speed difference between the two ends that can ensure safe closing of the second clutch.

[0118] like Figure 1 The two ends of the K2 clutch 1032 (second clutch) are the first motor 101 (front drive motor) and the engine 104. When the vehicle controls the second input shaft to disengage, the torque of the front drive motor is reduced to 0NM, but the front drive motor may have a certain speed. The engine is in the starting state and the engine also has a certain speed. At this time, the front drive motor can be adjusted based on the engine speed so that the speed difference at both ends of the second clutch is less than the preset speed difference.

[0119] The step of adjusting the speed of the front-drive motor based on the speed of the engine so that the speed difference at both ends of the second clutch is less than the preset speed difference may include: obtaining the actual speed of the engine, determining a target speed that makes the speed difference at both ends of the second clutch less than the preset speed difference based on the actual speed of the engine, and controlling the speed adjustment of the front-drive motor based on the target speed. When the actual speed of the front-drive motor is equal to the target speed, it is determined that the speed difference at both ends of the second clutch is less than the preset speed difference, and at this time, the second clutch is controlled to close, so that the vehicle switches from the pure electric four-wheel drive mode to the series mode.

[0120] Specifically, after the TCU controls the even-numbered shaft (i.e., the second input shaft) to shift to neutral, it controls the front drive motor to adjust the speed so that the speed difference between the two ends of the second clutch is less than the preset speed difference, for example, 100 rpm. After monitoring that the speed difference between the two ends of the second clutch is less than the preset speed difference of 100 rpm, the TCU quickly closes the second clutch.

[0121] In the above method, the speed of the front-drive motor is adjusted to reduce the speed difference at both ends of the second clutch. After determining that the speed difference at both ends of the second clutch is less than the preset speed difference, the second clutch is controlled to close. This can ensure the safe and smooth closing of the second clutch, avoid impact or vibration when the second clutch is closed, and improve driving comfort and vehicle stability.

[0122] In one possible implementation, after controlling the second clutch to close, the method also includes: setting the actual operating mode of the vehicle to the series mode, and controlling the engine to drive the front drive motor to generate electricity through the second clutch to charge the vehicle's high-voltage battery.

[0123] After the second clutch is closed, the vehicle's operating mode is switched to the series mode. At this time, the actual operating mode of the vehicle is set to the series mode. After the actual operating mode of the vehicle is set to the series mode, the engine output torque can be controlled. The torque output by the engine drives the front drive motor to generate electricity through the second clutch, and the electricity generated by the front drive battery is transmitted to the vehicle's high-voltage motor to charge the high-voltage battery.

[0124] Specifically, after the TCU quickly closes the second clutch, it sends the actual state of the second clutch as a closed state to the HCU. After determining that the actual state of the second clutch is a closed state, the HCU sets the actual operation mode to the series mode, and controls the engine output torque to drive the front drive motor to generate electricity, and charges the high-voltage battery based on the electricity generated by the front drive motor to supplement the loss of the high-voltage battery.

[0125] In the above method, after the vehicle switches to the series mode, the engine is controlled to drive the front drive motor to generate electricity through the second clutch, thereby charging the vehicle's high-voltage battery, ensuring the power of the high-voltage battery, and avoiding the high-voltage battery from running out for a long time.

[0126] In summary, in the process of switching the vehicle from the pure electric four-wheel drive mode to the direct drive mode, when the target gear is an odd gear, if it is determined that the odd gear is not available, it is directly judged whether the vehicle meets the conditions for switching to the series mode, and the vehicle is controlled to switch from the pure electric four-wheel drive mode to the series mode under the conditions of switching to the series mode. In the series mode, the engine continues to run, avoiding frequent engine starting, and avoiding the vehicle prohibiting the engine from starting due to multiple engine starts. In the series mode, the engine can drive the front drive motor to generate electricity and charge the high-voltage battery, thereby ensuring the power performance of the vehicle and improving the driving safety of the vehicle. In the case of multiple attempts to start the engine and control the first input shaft to switch to the direct drive mode in an odd gear, it is finally determined that the odd gear is not available, which improves the accuracy of judging the availability of the odd gear and reduces the possibility of misjudgment caused by a single failure. Modifying the target operation mode to the series mode can clarify the target operation mode that needs to be switched at present, improve the clarity of the vehicle mode switching logic, and in the process of switching the series mode, the front drive motor is controlled to reduce torque and then the second input shaft is controlled to disengage, thereby avoiding the situation that the front drive motor is prone to flying without load after the second input shaft is disengaged.

[0127] Figure 3 is a schematic diagram of a control mode switching device provided in an embodiment of the present application. The device is applied to include Figure 1 The vehicle includes a hybrid transmission 103, which includes a first input shaft 1033 and a second input shaft 1034, wherein the first input shaft 1033 is connected to a first clutch, and the second input shaft is connected to a second clutch. Figure 1 The K1 clutch 1031 in the second clutch is Figure 1 K2 clutch 1032 in.

[0128] For example, Figure 3 As shown, the device 300 includes:

[0129] The first judgment module 301 is used to judge whether the odd gear is available when the vehicle switches from the pure electric four-wheel drive mode to the direct drive mode if the target gear is an odd gear; wherein the first clutch is in an open state and the second clutch is in an open state in the pure electric four-wheel drive mode;

[0130] The second judgment module 302 is used to judge whether the vehicle meets the preset condition of switching to the series mode when it is determined that the odd gear is unavailable;

[0131] The control module 303 is used to control the engine of the vehicle to be in a running state and control the second clutch to close so that the vehicle switches from the pure electric four-wheel drive mode to the series mode when it is determined that the vehicle meets the preset conditions.

[0132] In one possible implementation, the first judgment module 301 is specifically used to, if the target gear is an odd gear, start the engine, record the number of times the engine is started, and control the first input shaft to shift into the odd gear; if the shifting into the odd gear fails, control the engine to stop; if the number of starts is less than the preset number, start the engine again, record the number of times the engine is started, and control the first input shaft to shift into the odd gear until the number of starts is equal to the preset number; if the number of starts is equal to the preset number, if the shifting into the odd gear still fails, it is determined that the odd gear is unavailable.

[0133] In one possible implementation, the first judgment module 301 is specifically used to determine whether the time for engaging the odd gear is greater than the preset time; when the time for engaging the odd gear is greater than the preset time and the actual gear position of the first input shaft is neutral, it is determined that engaging the odd gear is unsuccessful.

[0134] In one possible implementation, the second judgment module 302 is specifically used to, when it is determined that the odd gear is not available, if it is determined that the target operation mode of the vehicle is the direct drive mode, the actual operation mode is the pure electric four-wheel drive mode, the first clutch is in the open state, the second clutch is in the open state, the second input shaft is in the even gear, and the first input shaft is in neutral, then determine whether the vehicle meets the preset conditions for switching to the series mode.

[0135] In one possible implementation, the control module 303 is specifically used to control the front drive motor of the vehicle to reduce torque; when the actual torque of the front drive motor is less than or equal to the target torque, control the second input shaft to disengage; when it is determined that the second input shaft is in neutral, control the second clutch to close.

[0136] In a possible implementation, the control module 303 is specifically configured to modify the target operation mode of the vehicle to the series mode; when the target operation mode is the series mode, control the front drive motor of the vehicle to reduce torque.

[0137] In one possible implementation, the control module 303 is specifically used to, when it is determined that the second input shaft is in neutral, control the speed of the front drive motor so that the speed difference between the two ends of the second clutch is less than the preset speed difference; when it is determined that the speed difference between the two ends of the second clutch is less than the preset speed difference, control the second clutch to close.

[0138] Figure 4 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application.

[0139] For example, Figure 4As shown, the vehicle 400 includes: a memory 401 and a processor 402, wherein the memory 401 stores an executable program code 4011, and the processor 402 is used to call and execute the executable program code 4011 to perform a method for switching a control mode.

[0140] In addition, an embodiment of the present application also protects a device, which may include a memory and a processor, wherein the memory stores an executable program code, and the processor is used to call and execute the executable program code to perform a method for control mode switching provided in an embodiment of the present application.

[0141] In this embodiment, the functional modules of the device can be divided according to the above method example. For example, each functional module can be corresponded, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0142] In the case of dividing each functional module according to each function, the device may also include a first judgment module, a second judgment module and a control module, etc. It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0143] It should be understood that the device provided in this embodiment is used to execute the above-mentioned method for switching control modes, and thus can achieve the same effect as the above-mentioned implementation method.

[0144] In the case of an integrated unit, the device may include a processing module and a storage module. When the device is applied to a vehicle, the processing module may be used to control and manage the actions of the vehicle. The storage module may be used to support the vehicle in executing relevant program codes, etc.

[0145] The processing module may be a processor or a controller, which may implement or execute various exemplary logic blocks, modules and circuits shown in combination with the contents disclosed in this application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory.

[0146] In addition, the device provided in the embodiments of the present application may specifically be a chip, a component or a module, and the chip may include a connected processor and a memory; wherein the memory is used to store instructions, and when the processor calls and executes the instructions, the chip can execute a method of control mode switching provided in the above embodiments.

[0147] This embodiment also provides a computer-readable storage medium, in which a computer program code is stored. When the computer program code is executed on a computer, the computer executes the above-mentioned related method steps to implement a control mode switching method provided in the above embodiment.

[0148] This embodiment further provides a computer program product. When the computer program product is run on a computer, the computer is caused to execute the above-mentioned related steps to implement a control mode switching method provided in the above embodiment.

[0149] Among them, the device, computer-readable storage medium, computer program product or chip provided in this embodiment is used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be repeated here.

[0150] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0151] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0152] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for switching a control mode, characterized in that: A hybrid vehicle is applied, the vehicle includes a hybrid transmission, the hybrid transmission includes: a first input shaft and a second input shaft, the first input shaft is connected to a first clutch, the second input shaft is connected to a second clutch, the first input shaft includes an odd gear, the method includes: When the vehicle switches from the pure electric four-wheel drive mode to the direct drive mode, if the target gear is the odd gear, determining whether the odd gear is available; wherein, in the pure electric four-wheel drive mode, the first clutch is in an open state, and the second clutch is in an open state; In the case where it is determined that the odd gear is unavailable, determining whether the vehicle meets a preset condition for switching from the pure electric four-wheel drive mode to the series mode; When it is determined that the vehicle meets the preset condition, the engine of the vehicle is controlled to be in a running state, and the second clutch is controlled to be closed, so that the vehicle switches from the pure electric four-wheel drive mode to the series mode.

2. The method according to claim 1, characterized in that If the target gear is an odd gear, determining whether the odd gear is available includes: If the target gear is an odd gear, the engine is started, the number of times the engine is started is recorded, and the first input shaft is controlled to be engaged in an odd gear, and if the engagement in the odd gear is unsuccessful, the engine is controlled to be stopped; When the number of starts is less than the preset number, the engine is started again, the number of starts of the engine is recorded, and the first input shaft is controlled to shift into an odd gear until the number of starts is equal to the preset number; When the number of starts is equal to the preset number of times, if shifting into an odd-numbered gear still fails, it is determined that the odd-numbered gear is unavailable.

3. The method according to claim 2, characterized in that Ways to determine if shifting into an odd-numbered gear is unsuccessful include: Determine whether the duration of being in an odd-numbered gear is greater than a preset duration; When the duration of engaging the odd-numbered gear is greater than the preset duration and the actual gear position of the first input shaft is neutral, it is determined that engaging the odd-numbered gear is unsuccessful.

4. The method according to any one of claims 1 to 3, characterized in that When it is determined that the odd gear is unavailable, judging whether the vehicle meets a preset condition for switching to the series mode includes: When it is determined that the odd gear is unavailable, if it is determined that the target operating mode of the vehicle is the direct drive mode, the actual operating mode is the pure electric four-wheel drive mode, the first clutch is in the open state, the second clutch is in the open state, the second input shaft is in the even gear, and the first input shaft is in neutral, then it is determined whether the vehicle meets the preset conditions for switching to the series mode.

5. The method according to any one of claims 1 to 3, characterized in that: The controlling the second clutch to close comprises: Controlling the front drive motor of the vehicle to reduce torque; When the actual torque of the front-drive motor is less than or equal to the target torque, controlling the second input shaft to disengage the gear; When it is determined that the second input shaft is in neutral, the second clutch is controlled to close.

6. The method according to claim 5, characterized in that The controlling the front drive motor of the vehicle to reduce torque comprises: modifying a target operating mode of the vehicle to a series mode; When the target operation mode is the series mode, the front drive motor of the vehicle is controlled to reduce torque.

7. The method according to claim 5, characterized in that When it is determined that the second input shaft is in neutral, controlling the second clutch to close comprises: When it is determined that the second input shaft is in neutral, controlling the front drive motor to adjust the speed so that the speed difference between the two ends of the second clutch is less than a preset speed difference; When it is determined that the speed difference between the two ends of the second clutch is smaller than the preset speed difference, the second clutch is controlled to close.

8. A device for controlling mode switching, characterized in that: A hybrid vehicle is applied, the vehicle includes a hybrid transmission, the hybrid transmission includes: a first input shaft and a second input shaft, the first input shaft is connected to a first clutch, the second input shaft is connected to a second clutch, the first input shaft includes an odd gear, and the device includes: A first judgment module is used for judging whether the odd-numbered gear is available when the target gear is the odd-numbered gear during the process of the vehicle switching from the pure electric four-wheel drive mode to the direct drive mode; wherein the first clutch is in an open state and the second clutch is in an open state in the pure electric four-wheel drive mode; A second judgment module is used to judge whether the vehicle meets a preset condition for switching from the pure electric four-wheel drive mode to the series mode when it is determined that the odd gear is unavailable; The control module is used to control the engine of the vehicle to be in a running state and control the second clutch to close so that the vehicle switches from the pure electric four-wheel drive mode to the series mode when it is determined that the vehicle meets the preset conditions.

9. A vehicle, characterized in that: The vehicle comprises: A memory for storing executable program codes; A processor, configured to call and run the executable program code from the memory, so that the vehicle executes the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed, the method according to any one of claims 1 to 7 is implemented.

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