Method for controlling reversing of vehicle, vehicle and storage medium

Abstract

The invention provides a method for controlling reversing of a vehicle, the vehicle and a storage medium, the method is applied to the technical field of vehicles, and the method comprises the steps that under the condition that the actual operation mode of the vehicle is an idling hybrid power four-wheel drive mode, the actual gear of a gear lever of the vehicle is monitored; when it is monitored that the actual gear of the gear lever is switched to the R gear, whether the vehicle meets the preset condition of switching to the idling pure electric four-wheel drive mode or not is judged; and under the condition that it is determined that the vehicle meets the preset conditions, the actual operation mode of the vehicle is controlled to be switched from the idling hybrid power four-wheel drive mode to the idling pure electric four-wheel drive mode, so that the vehicle backs up in the idling pure electric four-wheel drive mode. According to the method, four-wheel drive vehicle reversing can be achieved, the power performance during vehicle reversing is guaranteed, and the problem of insufficient power during vehicle reversing is solved.

Description

Technical Field

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

[0002] Hybrid vehicles are gradually becoming an important choice in the automotive market and showing strong development potential due to their advantages in environmental protection, energy saving and meeting different driving needs, combined with policy support and growing market demand.

[0003] The gear lever positions of hybrid vehicles include: P gear (parking gear), D gear (drive gear), R gear (reverse gear), N gear (neutral gear) and other gears. Among them, when the gear lever is switched to R gear, the vehicle needs to reverse. Hybrid vehicles are prone to weak power when reversing, affecting the user's driving experience. Summary of the invention

[0004] The present application provides a method for controlling vehicle reversing, a vehicle and a storage medium, wherein the method can realize reversing of a four-wheel drive vehicle, ensure the power performance of the vehicle when reversing, and avoid the problem of insufficient power when reversing the vehicle.

[0005] In a first aspect, a method for controlling vehicle reversing is provided, which is applied to a hybrid vehicle, the vehicle comprising a hybrid transmission, the hybrid transmission comprising: 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 method comprising: when the actual operating mode of the vehicle is an idle hybrid four-wheel drive mode, monitoring the actual gear position of the vehicle's gear lever; wherein in the idle hybrid four-wheel drive mode, the vehicle's engine is in an idle state, the first clutch is in a slipping state, the second clutch is in a closed state, the vehicle's rear-drive motor is in a driving state, and the engine drives the vehicle's front-drive motor to rotate , so that the front-drive motor charges the vehicle's battery; when it is monitored that the actual gear position of the gear lever is switched to the R gear, it is determined whether the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode; wherein, in the idle pure electric four-wheel drive mode, the vehicle's engine is in an idle state, the vehicle's front-drive motor and rear-drive motor are in a driving state, the first clutch and the second clutch are both in an open state, the front-drive motor drives the vehicle's front wheels, and the rear-drive motor drives the vehicle's rear wheels; when it is determined that the vehicle meets the preset conditions, the vehicle's actual operating mode is controlled to switch from the idle hybrid four-wheel drive mode to the idle pure electric four-wheel drive mode, so that the vehicle can reverse in the idle pure electric four-wheel drive mode.

[0006] In the above technical solution, when the actual operation mode of the vehicle is the idle hybrid four-wheel drive mode, after monitoring that the actual gear position of the vehicle's gear lever is switched to the R gear, it is determined that the vehicle currently needs to reverse, and after determining that the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode, the vehicle is controlled to switch to the idle pure electric four-wheel drive mode, so that the vehicle reverses in the idle pure electric four-wheel drive mode. In the idle pure electric four-wheel drive mode, the front wheels of the vehicle are driven by the front drive motor and the rear wheels are driven by the rear drive motor. Even if there is no mechanical R gear in the vehicle's hybrid transmission, the vehicle can rely on the front drive motor to drive the front wheels to reverse, realize the four-wheel drive vehicle reverse, ensure the power performance of the vehicle when reversing, and avoid the problem of insufficient power when the vehicle is reversing. In the idle pure electric four-wheel drive mode, the engine of the vehicle maintains idling, that is, the engine is always maintained in a running state, so that when the vehicle switches to an operation mode that requires the use of the engine, the engine does not need to be started again, avoiding frequent start and stop of the engine, while improving the efficiency of subsequent mode switching and improving the user's car experience.

[0007] In combination with the first aspect, in certain possible implementations, when it is monitored that the actual gear position of the gear lever is switched to the R gear, it is determined whether the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode, including: when it is monitored that the actual gear position of the gear lever is switched to the R gear, it is determined whether the vehicle's hybrid transmission includes a mechanical R gear; when the hybrid transmission does not include a mechanical R gear, it is determined whether the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode.

[0008] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, controlling the actual operating mode of the vehicle to switch from the idle hybrid four-wheel drive mode to the idle pure electric four-wheel drive mode includes: controlling both the first clutch and the second clutch to open; when the second clutch is in the open state, controlling the synchronizer corresponding to the second input shaft to shift gears.

[0009] In combination with the first aspect and the above-mentioned implementation methods, in certain possible implementation methods, controlling the first clutch and the second clutch to open includes: controlling the absolute value of the actual torque of the vehicle's front drive motor and the absolute value of the actual torque of the engine to decrease; when the absolute value of the actual torque of the front drive motor is less than or equal to the first target torque and the absolute value of the actual torque of the engine is less than or equal to the second target torque, controlling the first clutch and the second clutch to open.

[0010] In the above technical solution, by controlling the absolute value of the actual torque of the front-drive motor to be reduced to less than or equal to the first target torque, and the absolute value of the actual torque of the engine to be reduced to less than or equal to the second target torque, the clutch is controlled to open, thereby reducing the inertia of the front-drive motor and the engine after the clutch is opened, avoiding the front-drive motor and the engine from spinning, reducing damage to the front-drive motor and the engine, and improving the safety of vehicle operation mode switching.

[0011] In combination with the first aspect and the above-mentioned implementation methods, in certain possible implementation methods, when the second clutch is in an open state, the synchronizer corresponding to the second input shaft is controlled to engage gear, including: when the second clutch is in an open state, the speed of the vehicle's front drive motor is adjusted according to the speed of the output shaft of the hybrid transmission to reduce the speed difference between the two ends of the synchronizer of the second input shaft; when the speed difference between the two ends of the synchronizer of the second input shaft is less than the preset speed difference, the synchronizer corresponding to the second input shaft is controlled to engage gear.

[0012] In the above technical solution, after the second clutch is opened, the rotation of the front-drive motor is controlled based on the speed of the output shaft of the hybrid transmission, which can reduce the speed difference at both ends of the synchronizer of the second input shaft. When the speed difference at both ends of the synchronizer of the second input shaft is less than the preset speed difference, the synchronizer corresponding to the second input shaft is controlled to engage gear, thereby avoiding severe impact between gears caused by gear switching when the speed difference is too large, protecting the hybrid transmission and other transmission system components, achieving smooth gear switching, and improving driving comfort and vehicle stability.

[0013] In combination with the first aspect and the above-mentioned implementation methods, in certain possible implementation methods, when the speed difference at both ends of the synchronizer of the second input shaft is less than the preset speed difference, the synchronizer corresponding to the second input shaft is controlled to engage gear, including: when the speed difference at both ends of the synchronizer of the second input shaft is less than the preset speed difference, controlling the torque of the front-drive motor to reduce the torque to the third target torque; when the torque of the front-drive motor is equal to the third target torque, controlling the synchronizer corresponding to the second input shaft to engage gear.

[0014] In the above technical solution, the front drive motor is controlled to reduce torque to the third target torque before the synchronizer corresponding to the second input shaft is engaged, and the gear engagement operation is performed only after confirming that the actual torque of the front drive motor is equal to the third target torque, thereby effectively avoiding torque fluctuations and unnecessary drive output that may occur during the gear shifting process. It is also avoided that the front drive motor outputs torque in advance, causing the vehicle to move suddenly without being prepared, which affects driving safety.

[0015] In combination with the first aspect and the above-mentioned implementation methods, in certain possible implementation methods, when the second clutch is in an open state, the front drive motor of the vehicle is speed-regulated according to the speed of the output shaft of the hybrid transmission to reduce the speed difference between the two ends of the synchronizer of the second input shaft, including: when the second clutch is in an open state, a target gear request for the second input shaft is sent to the TCU of the vehicle, and a shift permission instruction is sent to the TCU and the FMCU of the vehicle, so that after receiving the target gear request and the shift permission instruction of the second input shaft, the TCU sends a speed control activation request and a target speed request to the FMCU; wherein the target speed request includes a target speed, and the target speed is determined based on the speed of the output shaft; after receiving the shift permission instruction and the speed control activation request, the FMCU enters a speed control mode, and after entering the speed control mode and receiving the target speed request, controls the front drive motor to rotate to follow the target speed to reduce the speed difference between the two ends of the synchronizer of the second input shaft.

[0016] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, when the speed difference at both ends of the synchronizer of the second input shaft is less than the preset speed difference, the torque of the front-drive motor is controlled to be reduced to the third target torque, including: when the speed difference at both ends of the synchronizer of the second input shaft is less than the preset speed difference, a speed control deactivation request is sent to the FMCU, so that the FMCU switches to the torque control mode after receiving the speed control deactivation request; when it is determined that the FMCU has switched to the torque control mode, the torque of the front-drive motor is controlled to be reduced to the third target torque.

[0017] In summary, when the vehicle is in the idling hybrid four-wheel drive mode, the present application monitors that the actual gear position of the vehicle's gear lever is switched to the R gear and the vehicle meets the preset conditions for switching to the idling pure electric four-wheel drive mode, and controls the vehicle to switch to the idling pure electric four-wheel drive mode, so that the vehicle can reverse in the idling pure electric four-wheel drive mode. Even if there is no mechanical R gear in the vehicle's hybrid transmission, the vehicle can also rely on the front drive motor to drive the front wheels to reverse, so as to achieve the reverse of the four-wheel drive vehicle, ensure the power performance of the vehicle when reversing, and avoid the problem of insufficient power when reversing the vehicle. In the idling pure electric four-wheel drive mode, the engine of the vehicle maintains idling, avoiding frequent engine start and stop, and improving the user's car experience. After the absolute value of the actual torque of the front drive motor and the absolute value of the actual torque of the engine are controlled to be reduced, the clutch is controlled to open, so as to avoid the front drive motor and the engine from spinning. The speed difference between the two ends of the synchronizer of the second input shaft is reduced before the synchronizer corresponding to the second input shaft is controlled to engage in gear, which avoids the violent impact between gears caused by gear switching when the speed difference is too large, protects the hybrid transmission and other transmission system components, and achieves smooth gear switching. The front drive motor is controlled to reduce torque before the synchronizer corresponding to the second input shaft engages in gear, which avoids the front drive motor outputting torque in advance, causing the vehicle to move suddenly without being ready, affecting driving safety.

[0018] In a second aspect, a device for controlling vehicle reversing is provided, which is applied to a hybrid vehicle, wherein the vehicle includes a hybrid transmission, and the hybrid transmission includes: a first input shaft and a second input shaft, the first input shaft is connected to a first clutch, and the second input shaft is connected to a second clutch, and the device includes: a monitoring module, which is used to monitor the actual gear position of the vehicle's gear lever when the actual operating mode of the vehicle is an idle hybrid four-wheel drive mode; wherein, in the idle hybrid four-wheel drive mode, the vehicle's engine is in an idle state, the first clutch is in a slipping state, the second clutch is in a closed state, the vehicle's rear drive motor is in a driving state, and the engine drives the vehicle's front drive motor to rotate, so that The front-drive motor charges the vehicle's battery; a judgment module is used to judge whether the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode when it is detected that the actual gear position of the gear lever is switched to the R gear; wherein, in the idle pure electric four-wheel drive mode, the vehicle's engine is in an idle state, the vehicle's front-drive motor and rear-drive motor are in a driving state, the first clutch and the second clutch are both in an open state, the front-drive motor drives the vehicle's front wheels, and the rear-drive motor drives the vehicle's rear wheels; a control module is used to control the vehicle's actual operating mode to switch from the idle hybrid four-wheel drive mode to the idle pure electric four-wheel drive mode when it is determined that the vehicle meets the preset conditions, so that the vehicle can reverse in the idle pure electric four-wheel drive mode.

[0019] In combination with the second aspect, in some possible implementations, the judgment module is specifically used to, when monitoring that the actual gear position of the gear lever is switched to the R gear, determine whether the vehicle's hybrid transmission includes a mechanical R gear; when the hybrid transmission does not include a mechanical R gear, determine whether the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode.

[0020] In combination with the second aspect and the above-mentioned implementations, in some possible implementations, the control module is specifically used to control both the first clutch and the second clutch to be opened; when the second clutch is in an open state, control the synchronizer corresponding to the second input shaft to be engaged.

[0021] 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 absolute value of the actual torque of the front drive motor and the absolute value of the actual torque of the engine of the vehicle to decrease; when the absolute value of the actual torque of the front drive motor is less than or equal to the first target torque and the absolute value of the actual torque of the engine is less than or equal to the second target torque, the first clutch and the second clutch are controlled to open.

[0022] In combination with the second aspect and the above-mentioned implementation methods, in certain possible implementation methods, the control module is specifically used to, when the second clutch is in an open state, adjust the speed of the vehicle's front drive motor according to the rotational speed of the output shaft of the hybrid transmission to reduce the speed difference between the two ends of the synchronizer of the second input shaft; when the speed difference between the two ends of the synchronizer of the second input shaft is less than the preset speed difference, control the synchronizer corresponding to the second input shaft to engage gear.

[0023] 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 torque of the front-drive motor to be reduced to the third target torque when the speed difference at both ends of the synchronizer of the second input shaft is less than the preset speed difference; and to control the synchronizer corresponding to the second input shaft to engage gear when the torque of the front-drive motor is equal to the third target torque.

[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, when the second clutch is in an open state, send a target gear request for the second input shaft to the TCU of the vehicle, and send a shift permission instruction to the TCU and the FMCU of the vehicle, so that after receiving the target gear request and the shift permission instruction of the second input shaft, the TCU sends a speed control activation request and a target speed request to the FMCU; wherein the target speed request includes a target speed, and the target speed is determined based on the speed of the output shaft; after receiving the shift permission instruction and the speed control activation request, the FMCU enters the speed control mode, and after entering the speed control mode and receiving the target speed request, controls the front drive motor to rotate according to the target speed to reduce the speed difference between the two ends of the synchronizer of the second input shaft.

[0025] 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 torque of the front-drive motor to be reduced to a third target torque when the speed difference at both ends of the synchronizer of the second input shaft is less than the preset speed difference, including: when the speed difference at both ends of the synchronizer of the second input shaft is less than the preset speed difference, sending a speed control deactivation request to the FMCU, so that the FMCU switches to the torque control mode after receiving the speed control deactivation request; when it is determined that the FMCU has switched to the torque control mode, controlling the torque of the front-drive motor to be reduced to the third target torque.

[0026] 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.

[0027] 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.

[0028] 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

[0029] Figure 1 It is a schematic diagram of the architecture of a hybrid vehicle provided in an embodiment of the present application.

[0030] Figure 2 It is a schematic flowchart of a method for controlling vehicle reversing provided in an embodiment of the present application.

[0031] Figure 3 It is a timing diagram of switching from an idle hybrid four-wheel drive mode to an idle pure electric four-wheel drive mode provided in an embodiment of the present application.

[0032] Figure 4 It is a structural schematic diagram of a device for controlling vehicle reversing provided in an embodiment of the present application.

[0033] Figure 5 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. In some embodiments, the gears of the hybrid transmission 103 do not include a mechanical R gear for changing the power transmission direction. 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 idle hybrid four-wheel drive mode, the K1 clutch 1031 of the vehicle is in a slipping state, the K2 clutch 1032 is in a closed state, the engine 104 is kept in an idle state, the second motor 106 is in a driving state, the first synchronizer 1035 selects to engage in the first gear on the first input shaft 1033, and the second synchronizer 1036 engages in neutral gear on the second input shaft 1034. In the idle hybrid four-wheel drive mode, the engine 104 drives the first motor 101 to operate and generate electricity through the K2 clutch 1032, and the electric energy generated by the first motor 101 can charge the high-voltage battery 105, and the engine 104 outputs power through the slipping K1 clutch 1031 to drive the front wheels 107 of the vehicle, and the second motor 106 outputs power to drive the rear wheels 108 of the vehicle.

[0049] The clutch being in a slipping state can be understood as: the clutch is not fully engaged, and there is a certain speed difference between the gears on both sides of the clutch.

[0050] In the idling pure electric four-wheel drive mode, the vehicle's K1 clutch 1031 is in an open state, the K2 clutch 1032 is in an open state, the engine 104 remains in an idling state, the first motor 101 and the second motor 106 are both in a driving state, the second synchronizer 1036 selects the second gear on the second input shaft 1034, the engine 104 is idling, the first motor 101 outputs power to drive the vehicle's front wheels 107, and the second motor 106 outputs power to drive the vehicle's rear wheels 108.

[0051] If the gear position of the hybrid transmission of the vehicle based on the above architecture does not include the mechanical R gear, the engine cannot participate in reversing. If the vehicle is reversing in the idle hybrid four-wheel drive mode, since the engine drives the front wheels of the vehicle in the idle hybrid four-wheel drive mode, the engine cannot participate in reversing and the front drive motor is generating electricity, the vehicle can only start reversing by driving the rear wheels of the vehicle through the rear drive motor when reversing, resulting in weak reversing power of the vehicle. For scenarios such as reversing and starting the vehicle or reversing uphill, the vehicle is prone to slipping if it is driven only by the rear wheels, resulting in problems with starting or climbing difficulties, affecting the user's driving experience.

[0052] Based on this, the present application proposes a method for controlling vehicle reversing to increase the power of the vehicle when reversing and improve the user's driving experience.

[0053] Figure 2 is a schematic flow chart of a method for controlling vehicle reversing provided by an embodiment of the present application. The method is applied to a vehicle including 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.

[0054] For example, Figure 2 As shown, the method 200 includes:

[0055] Step 201, when the actual operation mode of the vehicle is the idle hybrid four-wheel drive mode, monitoring the actual gear position of the gear lever of the vehicle; wherein, in the idle hybrid four-wheel drive mode, the engine of the vehicle is in an idle state, the first clutch is in a slipping state, the second clutch is in a closed state, the rear drive motor of the vehicle is in a driving state, and the engine drives the front drive motor of the vehicle to rotate, so that the front drive motor charges the battery of the vehicle;

[0056] Step 202, when it is detected that the actual gear position of the gear lever is switched to the R gear, it is determined whether the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode; wherein, in the idle pure electric four-wheel drive mode, the engine of the vehicle is in an idle state, the front drive motor and the rear drive motor of the vehicle are in a driving state, the first clutch and the second clutch are both in an open state, the front drive motor drives the front wheels of the vehicle, and the rear drive motor drives the rear wheels of the vehicle;

[0057] Step 203, when it is determined that the vehicle meets the preset conditions, the actual operation mode of the vehicle is controlled to switch from the idle hybrid four-wheel drive mode to the idle pure electric four-wheel drive mode, so that the vehicle reverses in the idle pure electric four-wheel drive mode.

[0058] exist Figure 2 In the illustrated embodiment, when the actual operation mode of the vehicle is the idle hybrid four-wheel drive mode, after monitoring that the actual gear position of the vehicle's gear lever has switched to the R gear, it is determined that the vehicle currently needs to reverse, and after determining that the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode, the vehicle is controlled to switch to the idle pure electric four-wheel drive mode, so that the vehicle reverses in the idle pure electric four-wheel drive mode. In the idle pure electric four-wheel drive mode, the front wheels of the vehicle are driven by the front drive motor and the rear wheels are driven by the rear drive motor. Even if there is no mechanical R gear in the vehicle's hybrid transmission, the vehicle can rely on the front drive motor to drive the front wheels to reverse, so as to achieve the reverse of the four-wheel drive vehicle, ensure the power performance of the vehicle when reversing, and avoid the problem of insufficient power when reversing. In the idle pure electric four-wheel drive mode, the engine of the vehicle maintains idling, that is, the engine is always maintained in a running state, so that when the vehicle switches to an operation mode that requires the use of the engine, the engine does not need to be started again, thereby avoiding frequent starting and stopping of the engine, and at the same time improving the efficiency of subsequent mode switching and improving the user's car experience.

[0059] Below Figure 2 The specific implementation of each step in the embodiment shown is described in detail:

[0060] In step 201, in the idle hybrid four-wheel drive mode, the engine of the vehicle is in idle operation, and the engine outputs power to the front wheels of the vehicle to drive the vehicle to travel. The rear drive motor of the vehicle is in operation, and the rear drive motor outputs power to the rear wheels of the vehicle to drive the vehicle to travel.

[0061] The actual gear position of the vehicle's gear lever is manually selected by the driver, usually operated by a physical gear lever or an electronic button / knob. The gear positions of the gear lever include: P gear (parking gear), D gear (drive gear), R gear (reverse gear), N gear (neutral gear) and other gear positions.

[0062] P gear is the parking gear, which is used when the vehicle is stopped and is usually used to lock the wheels. The actual gear position of the gear lever is P gear, which means that the vehicle is currently in a parking state. D gear is the driving gear, which is used for normal vehicle driving (i.e. driving forward). When the actual gear position of the gear lever is D gear, the hybrid transmission will automatically select the appropriate forward gear (such as 1st gear, 2nd gear, 3rd gear or 4th gear, etc.) according to the actual operating mode, vehicle speed and load to provide the best power output and fuel economy. R gear is the reverse gear, which is used for the vehicle to drive backward. When the actual gear position of the gear lever is R gear, the front drive motor or the rear drive motor will reverse, and the power output of the front drive motor or the rear drive motor can make the front wheel or the rear wheel rotate in the opposite direction, so that the vehicle moves backward. N gear is the neutral gear, which is used to cut off the power connection between the engine and the wheels. When the gear lever is in N gear, the hybrid transmission will not transmit the power of the engine to the wheels, and the vehicle can slide freely without power.

[0063] The actual gear position of the vehicle's gear lever can most directly reflect the driver's driving intention, so that the vehicle can adjust the vehicle's power output in a timely manner according to the driver's driving intention. The vehicle is usually in the idle hybrid four-wheel drive mode when parking. If the vehicle needs to park sideways or reverse into the garage, the driver will usually control the actual gear position of the gear lever to switch back and forth between D and R to continuously adjust the vehicle angle and control the vehicle to park. Therefore, when the actual operating mode of the vehicle is the idle hybrid four-wheel drive mode, it is necessary to monitor the actual gear position of the vehicle's gear lever.

[0064] In step 201, when the actual operation mode of the vehicle is the idle hybrid four-wheel drive mode, if the actual gear position of the vehicle gear lever is detected to be switched to the R gear, it can be determined that the vehicle currently needs to reverse, and it can be determined that the vehicle needs to switch the driving mode to the idle pure electric four-wheel drive mode to achieve the four-wheel drive vehicle reverse. Therefore, after the actual gear position of the vehicle gear lever is detected to be switched to the R gear, it is necessary to determine whether the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode.

[0065] The preset conditions for switching to the idle pure electric four-wheel drive mode may include: the remaining power of the high-voltage battery is greater than the preset power (e.g., 15%), the power of the high-voltage battery is greater than the preset power, etc. For example, when the remaining power of the high-voltage battery is greater than 15% of the preset power, and the power of the high-voltage battery is greater than the preset power, it is determined that the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode.

[0066] Among them, the preset power is a minimum power threshold set in advance to ensure that the vehicle has sufficient power to complete the current driving task or at least can safely switch back to other modes (such as series mode or parallel mode) to avoid battery damage caused by deep discharge of the high-voltage battery.

[0067] The preset power is a minimum power threshold set in advance to ensure that the high-voltage battery can provide sufficient power support when needed. The power output of the high-voltage battery may be affected by temperature, aging or other factors. By setting a minimum power threshold, the vehicle can ensure that it enters the idle pure electric four-wheel drive mode only when the battery performance is good, thereby optimizing energy management and driving experience.

[0068] In one possible implementation, when it is detected that the actual gear position of the gear lever is switched to the R gear, it is determined whether the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode, including: when it is detected that the actual gear position of the gear lever is switched to the R gear, it is determined whether the hybrid transmission of the vehicle includes a mechanical R gear; when the hybrid transmission does not include a mechanical R gear, it is determined whether the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode.

[0069] Among them, the mechanical R gear, also known as the reverse gear, is a special gear in the hybrid transmission. It is used to realize the reversing function by changing the rotation direction of the internal gears of the hybrid transmission to make the vehicle move backward.

[0070] In the idle hybrid four-wheel drive mode, the front wheels of the vehicle are driven by the engine output power. When the hybrid transmission includes a mechanical R gear, after the actual gear position of the gear lever is switched to R gear, the hybrid transmission can be shifted to the mechanical R gear to change the direction of the engine output power, causing the front wheels of the vehicle to rotate in the opposite direction, thereby moving the vehicle backward.

[0071] When the hybrid transmission does not include the mechanical R gear, after the actual gear position of the gear lever is switched to the R gear, the hybrid transmission cannot change the direction of the engine output power, and the engine cannot reverse, so the engine cannot participate in reversing in the idle hybrid four-wheel drive mode. In the idle pure electric four-wheel drive mode, the front wheels of the vehicle are driven by the output power of the front drive motor, and the front drive motor can drive the front wheels to rotate in the opposite direction by reversing the output power, thereby moving the vehicle backward. Therefore, when it is determined that the hybrid transmission does not include the mechanical R gear, in order to ensure the vehicle's four-wheel drive reversing, it can be determined whether the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode.

[0072] In step 203, when the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode, it can be determined that the vehicle can currently switch to the idle pure electric four-wheel drive mode. At this time, the actual operation mode of the vehicle is controlled to switch from the idle hybrid four-wheel drive mode to the idle pure electric four-wheel drive mode.

[0073] In the idle pure electric four-wheel drive mode, the engine is idling, the front-drive motor and the rear-drive motor are both reversed, the front-drive motor drives the front wheels of the vehicle, and the rear-drive motor drives the rear wheels of the vehicle to achieve four-wheel drive reverse.

[0074] In one possible implementation, the actual operating mode of the vehicle is controlled to switch from the idle hybrid four-wheel drive mode to the idle pure electric four-wheel drive mode, including: controlling both the first clutch and the second clutch to open; when the second clutch is in the open state, controlling the synchronizer corresponding to the second input shaft to engage gear.

[0075] Specifically, in the idle hybrid four-wheel drive mode, the first clutch of the vehicle is in a slipping state, and the second clutch is in a closed state. The engine drives the front wheels of the vehicle through the slipping first clutch, and drives the front drive motor to generate electricity through the closed second clutch. In the idle pure electric four-wheel drive mode, the first clutch and the second clutch are both in an open state. Therefore, when the actual operation mode of the vehicle is switched from the idle hybrid four-wheel drive mode to the idle pure electric four-wheel drive mode, it is necessary to control both the first clutch and the second clutch to be open.

[0076] In the idle hybrid four-wheel drive mode, the engine transmits power to the output shaft of the hybrid transmission through the first input shaft connected to the first clutch, so the synchronizer corresponding to the first input shaft is in odd gear. The first input shaft is the odd shaft, which includes odd gears 1 and 3. The synchronizer corresponding to the first input shaft is Figure 1 The synchronizer 1035 in the idling hybrid four-wheel drive mode is connected to the front drive motor through the second clutch and the second input shaft. At this time, the front drive motor is driven by the engine to generate electricity and does not output power. Therefore, the synchronizer corresponding to the second input shaft is in neutral gear. The second input shaft is an even-numbered shaft, which includes even-numbered gears 2 and 4. The synchronizer corresponding to the second input shaft is Figure 1 Synchronizer 1036 in.

[0077] In the idle pure electric four-wheel drive mode, the front-drive motor is running, and the front-drive motor is connected to the second input shaft, which needs to transmit power to the output shaft of the hybrid transmission through the second input shaft, so the second input shaft needs to be in gear. The gear-shifting operation needs to be performed when the clutch is open. Therefore, when the actual operation mode of the vehicle is switched from the idle hybrid four-wheel drive mode to the idle pure electric four-wheel drive mode, after determining that the second clutch is open, it is necessary to control the synchronizer corresponding to the second input shaft to shift gears, and the synchronizer corresponding to the second input shaft is in the even-numbered gear 2 or 4.

[0078] As in the above embodiment, when the vehicle is driving in a specific parking scenario, the vehicle speed is relatively low at this time, the gear position of the synchronizer corresponding to the first input shaft may be specifically 1st gear, and the even-numbered gear of the synchronizer corresponding to the second input shaft may be specifically 2nd gear.

[0079] In one possible implementation, controlling both the first clutch and the second clutch to open includes: controlling the absolute value of the actual torque of the front drive motor and the absolute value of the actual torque of the engine of the vehicle to decrease; and controlling both the first clutch and the second clutch to open when the absolute value of the actual torque of the front drive motor is less than or equal to the first target torque and the absolute value of the actual torque of the engine is less than or equal to the second target torque.

[0080] As in the above embodiment, in the idle hybrid four-wheel drive mode, the engine is in operation, that is, the engine outputs a certain torque, and the engine transmits part of the output torque to the wheels through the slipping first clutch, and also transmits part of the output torque to the front drive motor through the closed second clutch, and controls the front drive motor to generate electricity, that is, the front drive motor also has a certain torque at this time. In some embodiments, since the front drive motor is currently generating electricity, the torque of the front drive motor at this time is called negative torque. After the first clutch and the second clutch are both opened, the front drive motor and the engine are free of load, and the front drive motor and the engine are prone to flying.

[0081] In order to prevent the front-drive motor and the engine from spinning wildly after the first clutch and the second clutch are both opened, after determining that the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode, the absolute value of the actual torque of the front-drive motor and the absolute value of the actual torque of the engine can be controlled to decrease first, and after the absolute value of the actual torque of the front-drive motor is less than or equal to the first target torque and the absolute value of the actual torque of the engine is less than or equal to the second target torque, the first clutch and the second clutch are controlled to open.

[0082] The first target torque is a torque set in advance to ensure that the front drive motor does not spin fast, usually slightly greater than 0NM (Newton meter), for example, 3NM. At this time, it is necessary to control the absolute value of the actual torque of the front drive motor to be less than or equal to 3NM, so that the actual torque of the front drive motor is close to 0NM. The second target torque is usually slightly greater than the first target torque. When the second target torque can be an idle load torque that the engine can maintain a small idle rotation, for example, 5NM, it is necessary to control the actual torque of the engine to be less than or equal to 5NM.

[0083] In some embodiments, Figure 1The 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 an 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.

[0084] Specifically, when the actual operating mode of the vehicle is the idle hybrid four-wheel drive mode, if it is monitored that the actual gear position of the gear lever has become the R gear, it is determined that the actual operating mode of the vehicle needs to be switched from the idle hybrid four-wheel drive mode to the idle pure electric four-wheel drive mode. Assuming that the first input shaft (i.e., the odd-numbered shaft) of the vehicle is in 1st gear in the idle hybrid four-wheel drive mode, the HCU of the vehicle sends a signal to the TCU that the target gear position of the odd-numbered shaft is 1st gear, the target gear position of the even-numbered shaft is 2nd gear, the target direct drive gear position is 1st gear, the Idle H-AWD (idle hybrid four-wheel drive) mode is exited, the Idle E-AWD (idle pure electric four-wheel drive) mode is activated, the K2 clutch (i.e., the second clutch) is requested to close, and the K1 clutch (i.e., the first clutch) is requested to slip, so that the TCU can determine the current state of the vehicle. At the same time, the HCU controls the absolute value of the actual torque of the front drive motor and the absolute value of the actual torque of the engine to be close to 0NM, and after the absolute value of the actual torque of the motor is less than the first target torque of 3NM and the absolute value of the actual torque of the engine is less than the second target torque of 5NM, the TCU sends a K2 clutch opening request signal and a K1 clutch opening request signal. After receiving the K2 clutch opening request signal and the K1 clutch opening request signal sent by the HCU, the TCU controls the K2 clutch and controls the K1 clutch to open.

[0085] In some embodiments, controlling both the first clutch and the second clutch to open includes: first controlling the second clutch to open and then controlling the first clutch to open.

[0086] Specifically, the first clutch is used to output power to the front wheels of the vehicle, and the second clutch is used to drive the front drive motor to generate electricity. Controlling the second clutch to open first, that is, controlling the clutch that does not output power to the wheels to open first, can facilitate the operation of switching back to the idle hybrid four-wheel drive mode after the user switches the actual gear position of the gear lever to D gear after opening the second clutch. At this time, only the second clutch needs to be closed, which can improve the efficiency of mode switching.

[0087] Figure 3It is a timing diagram of switching from an idle hybrid four-wheel drive mode to an idle pure electric four-wheel drive mode provided in an embodiment of the present application.

[0088] For example, Figure 3 As shown, the switching of the idle hybrid four-wheel drive mode to the idle pure electric four-wheel drive mode includes four stages, namely: stage one (idle hybrid four-wheel drive mode), stage two (clutch control stage), stage three (gear control stage), and stage four (idle pure electric four-wheel drive mode).

[0089] In stage one, which is the idle hybrid four-wheel drive mode, the vehicle's engine is running at idle speed. The engine needs to output power so it rotates at a higher idle speed. The engine outputs a certain torque as the negative torque of the P2.5 motor, driving the P2.5 motor to generate electricity, and the P2.5 motor also rotates at a certain speed. The actual state of the K1 clutch (first clutch) is a slipping state, and the actual state of the K2 clutch (second clutch) is a closed state. The state request of the K1 clutch is a slipping request, and the state request of the K2 clutch is a closing request. The first synchronizer S1 is in a gear-entry completion state, and the second synchronizer S2 is in a gear-off completion state. The target gear request of the odd-numbered axis is 1st gear (Gear 1), the target gear request of the even-numbered axis is neutral (Gear N), and the target operation mode request is an idle hybrid four-wheel drive mode (Idle H-AWD).

[0090] In stage 2, the target operation mode request changes to the idle pure electric four-wheel drive mode (Idle E-AWD), the engine speed decreases, and the absolute value of the engine torque and the absolute value of the front-drive motor torque decrease. After the engine speed drops to the target idle speed corresponding to the idle pure electric four-wheel drive mode and the absolute value of the engine torque and the absolute value of the front-drive motor torque drop to 0NM, the state request of the K1 clutch changes to an open request, and the state request of the K2 clutch changes to an open request. After the state requests of the K1 clutch and the K2 clutch change to an open request, the actual state of the K1 clutch changes to an open state, and the actual state of the K2 clutch changes to an open state.

[0091] In the above method, the absolute value of the actual torque of the front-drive motor is controlled to be reduced to less than or equal to the first target torque, and the absolute value of the actual torque of the engine is reduced to less than or equal to the second target torque, and then the clutch is controlled to open, thereby reducing the inertia of the front-drive motor and the engine after the clutch is opened, avoiding the front-drive motor and the engine from spinning, reducing damage to the front-drive motor and the engine, and improving the safety of vehicle operation mode switching.

[0092] In a possible implementation, when the second clutch is in an open state, controlling the synchronizer corresponding to the second input shaft to engage a gear includes the following steps S11 to S12:

[0093] S11, when the second clutch is in an open state, the front drive motor of the vehicle is regulated according to the rotation speed of the output shaft of the hybrid transmission to reduce the speed difference between the two ends of the synchronizer of the second input shaft.

[0094] like Figure 1 As shown, the second input shaft includes a second synchronizer 1036 between the even-numbered gears 2 and 4, i.e., the synchronizer of the second input shaft. Before controlling the synchronizer corresponding to the second input shaft to engage in gear, the speed difference at both ends of the second synchronizer 1036 needs to be reduced to achieve safe gear engagement and avoid gear impact.

[0095] When the second clutch is in the open state, the two ends of the synchronizer of the second input shaft are the front-wheel drive motor and the output shaft of the hybrid transmission respectively. The output shaft of the hybrid transmission is connected to the front wheels of the vehicle. If the vehicle is currently moving, the output shaft of the hybrid transmission has a certain speed. At this time, the speed of the front-wheel drive motor can be adjusted based on the speed of the output shaft of the hybrid transmission to reduce the speed difference between the two ends of the synchronizer of the second input shaft.

[0096] In one possible implementation, when the second clutch is in an open state, the front drive motor of the vehicle is speed-regulated according to the rotational speed of the output shaft of the hybrid transmission to reduce the speed difference between the two ends of the synchronizer of the second input shaft, including: when the second clutch is in an open state, sending a target gear request for the second input shaft to the TCU of the vehicle, and sending a shift permission instruction to the TCU and the FMCU of the vehicle, so that after receiving the target gear request and the shift permission instruction of the second input shaft, the TCU sends a speed control activation request and a target speed request to the FMCU; wherein the target speed request includes a target speed, and the target speed is determined based on the speed of the output shaft; after receiving the shift permission instruction and the speed control activation request, the FMCU enters a speed control mode, and after entering the speed control mode and receiving the target speed request, controls the front drive motor to rotate to follow the target speed to reduce the speed difference between the two ends of the synchronizer of the second input shaft.

[0097] After the second clutch is opened, the second input shaft of the vehicle is disconnected from the engine. At this time, it can be determined that the second input shaft can start to shift gears. Therefore, after determining that the second clutch is opened, the HCU sends a target gear request for the second input shaft to the TCU, and sends a gear shift permission instruction to the TCU and the vehicle's FMCU.

[0098] After receiving the target gear request and shift permission instruction of the second input shaft sent by the HCU, the TCU determines that the vehicle currently allows the synchronizer corresponding to the second input shaft to engage in gear. Controlling the synchronizer corresponding to the second input shaft to engage in gear requires that the speed difference at both ends of the synchronizer of the second input shaft be reduced to less than the preset speed difference. As in the above embodiment, when the second clutch is in the open state, the two ends of the synchronizer of the second input shaft are the output shaft of the hybrid transmission and the front drive motor, respectively. At this time, the TCU can obtain the speed of the output shaft of the hybrid transmission, add a calibration value to the speed of the output shaft of the hybrid transmission, and obtain the target speed. The target speed is the target speed of the front drive motor. When the rotation of the front drive motor is equal to the target speed, the speeds of the two ends of the synchronizer of the second input shaft are the same.

[0099] After obtaining the target speed, the TCU sends a speed control activation request and a target speed request to the FMCU, and the target speed request includes the above target speed. After the FMCU receives the shift permission command sent by the HCU and the speed control activation request sent by the TCU, it enters the speed control mode. In the speed control mode, the FMCU controls the front drive motor to rotate based on the target speed. After entering the speed control mode and receiving the target speed request sent by the TCU, the FMCU controls the front drive motor to rotate according to the target speed to reduce the speed difference between the two ends of the synchronizer of the second input shaft.

[0100] S12, when the speed difference between the two ends of the synchronizer of the second input shaft is less than the preset speed difference, controlling the synchronizer corresponding to the second input shaft to engage a gear.

[0101] The preset speed difference is the maximum speed difference to ensure that the second input shaft can be safely shifted into gear. When the speed difference at both ends of the synchronizer of the second input shaft, i.e., the second synchronizer 1036, is less than the preset speed difference, it can be determined that the synchronizer corresponding to the second input shaft can be safely and smoothly controlled to shift into gear 2 or 4.

[0102] The vehicle may be provided with sensors for collecting speed at both ends of the synchronizer of the second input shaft. The TCU may obtain the speed collected by the sensors at both ends of the synchronizer of the second input shaft to calculate the speed difference during the process of adjusting the speed of the front drive motor, and determine whether the speed difference is less than the preset speed difference, such as 50 rpm (revolutions per minute). When the speed difference is less than the preset speed difference of 50 rpm, the TCU controls the synchronizer corresponding to the second input shaft to engage gear.

[0103] The target gear request of the second input shaft may also include a target even gear (eg, 2nd gear) to be engaged, so that the TCU controls the synchronizer corresponding to the second input shaft to engage the target even gear.

[0104] For example, Figure 3As shown, after the second clutch is opened, the target gear request of the even-numbered shaft in stage three becomes 2nd gear (Gear 2), the second synchronizer S2 becomes synchronized state, the speed of the front-drive motor starts to decrease, and after the speed of the front-drive motor decreases to the target speed of 2nd gear, the second synchronizer S2 becomes in gear shifting state, and after the gear shifting is completed, the second synchronizer S2 becomes gear shifting completed state.

[0105] like Figure 3 As shown, in stage three, after the second synchronizer S2 changes to the gear-up completion state, the torque of the front-drive motor begins to increase until the torque of the front-drive motor increases to the required torque of the front axle.

[0106] like Figure 3 As shown, in stage 4, that is, in the idle pure electric four-wheel drive mode, the engine maintains the target idle speed corresponding to the idle pure electric four-wheel drive mode. The front drive motor maintains the target speed of 2nd gear and outputs the front axle required torque to the front wheels of the vehicle. The first clutch and the second clutch are both in the open state, the first synchronizer and the second synchronizer maintain the gear completion state, the odd-numbered axle target gear position requests to maintain 1st gear, the even-numbered axle target gear position requests to maintain 2nd gear, and the target operation mode requests to maintain the idle pure electric four-wheel drive mode.

[0107] In the above method, after the second clutch is opened, the rotation of the front-drive motor is controlled based on the speed of the output shaft of the hybrid transmission, which can reduce the speed difference at both ends of the synchronizer of the second input shaft. When the speed difference at both ends of the synchronizer of the second input shaft is less than the preset speed difference, the synchronizer corresponding to the second input shaft is controlled to engage gear, thereby avoiding severe impact between gears caused by gear switching when the speed difference is too large, protecting the hybrid transmission and other transmission system components, achieving smooth gear switching, and improving driving comfort and vehicle stability.

[0108] In one possible implementation, when the speed difference between the two ends of the synchronizer of the second input shaft is less than a preset speed difference, the synchronizer corresponding to the second input shaft is controlled to engage gear, including: when the speed difference between the two ends of the synchronizer of the second input shaft is less than a preset speed difference, controlling the torque of the front-drive motor to reduce to a third target torque; when the torque of the front-drive motor is equal to the third target torque, controlling the synchronizer corresponding to the second input shaft to engage gear.

[0109] It can be understood that when the above-mentioned TCU controls the synchronizer corresponding to the second input shaft to engage gear, the FMCU enters the speed control mode to adjust the speed of the front-wheel drive motor. At this time, the front-wheel drive motor has a certain torque. At this time, the actual operation mode of the vehicle has not switched to the idle pure electric four-wheel drive mode, that is, the HCU has not yet issued an instruction to control the output torque of the front-wheel drive motor. After the synchronizer corresponding to the second input shaft is engaged, the actual operation mode of the vehicle will switch to the idle pure electric four-wheel drive mode.

[0110] In order to avoid the situation where the front-drive motor is already outputting torque before the HCU issues a command to control the front-drive motor to output torque after switching to the idle pure electric four-wheel drive mode, the front-drive motor needs to be controlled to reduce torque to the third target torque before the synchronizer corresponding to the second input shaft is controlled to engage gear. The third target torque can be 0NM to ensure that the front-drive motor does not output torque by itself after switching to the idle pure electric four-wheel drive mode.

[0111] After determining that the actual torque of the front-drive motor is equal to the third target torque 0 NM, the synchronizer corresponding to the second input shaft is controlled to shift into gear.

[0112] In the above method, by controlling the front drive motor to reduce torque to the third target torque before the synchronizer corresponding to the second input shaft is engaged, and the gear engagement operation is performed only after confirming that the actual torque of the front drive motor is equal to the third target torque, torque fluctuations and unnecessary drive output that may occur during the gear shifting process are effectively avoided. It is also avoided that the front drive motor outputs torque in advance, causing the vehicle to move suddenly without being prepared, affecting driving safety.

[0113] In one possible implementation, when the speed difference at both ends of the synchronizer of the second input shaft is less than the preset speed difference, the torque of the front-drive motor is controlled to be reduced to the third target torque, including: when the speed difference at both ends of the synchronizer of the second input shaft is less than the preset speed difference, a speed control deactivation request is sent to the FMCU, so that the FMCU switches to the torque control mode after receiving the speed control deactivation request; when it is determined that the FMCU has switched to the torque control mode, the torque of the front-drive motor is controlled to be reduced to the third target torque.

[0114] Specifically, when the speed difference between the two ends of the synchronizer of the second input shaft is less than the preset speed difference, it can be determined that the second input shaft can be safely controlled to engage in gear, and it is no longer necessary to control the front drive motor based on the target speed to reduce the speed difference between the two ends of the synchronizer of the second input shaft. At this time, the TCU sends a speed control deactivation request to the FMCU, so that the FMCU determines that it is no longer necessary to control the front drive motor based on the target speed.

[0115] After the FMCU determines that it is no longer necessary to control the front-drive motor based on the target speed, it switches to the torque control model. In the torque control mode, the FMCU controls the front-drive motor to rotate based on the target torque. At this time, the vehicle does not need to output torque, so the front-drive motor is controlled to reduce the torque to the third target torque of 0NM.

[0116] After the TCU detects that the speed difference between the two ends of the second synchronizer S2 is less than the preset speed difference of 50rpm and the torque of the front drive motor is reduced to 0Nm, it controls the synchronizer corresponding to the second input shaft to shift into gear through the second synchronizer S2.

[0117] In some embodiments, after determining that the second synchronizer S2 has been engaged, the HCU will further send a gear shift disallowing instruction to each control unit, and control the vehicle to reverse in the Idle E-AWD mode.

[0118] In summary, when the vehicle is in the idling hybrid four-wheel drive mode, the present application monitors that the actual gear position of the vehicle's gear lever is switched to the R gear and the vehicle meets the preset conditions for switching to the idling pure electric four-wheel drive mode, and controls the vehicle to switch to the idling pure electric four-wheel drive mode, so that the vehicle can reverse in the idling pure electric four-wheel drive mode. Even if there is no mechanical R gear in the vehicle's hybrid transmission, the vehicle can also rely on the front drive motor to drive the front wheels to reverse, so as to achieve the reverse of the four-wheel drive vehicle, ensure the power performance of the vehicle when reversing, and avoid the problem of insufficient power when reversing the vehicle. In the idling pure electric four-wheel drive mode, the engine of the vehicle maintains idling, avoiding frequent engine start and stop, and improving the user's car experience. After the absolute value of the actual torque of the front drive motor and the absolute value of the actual torque of the engine are controlled to be reduced, the clutch is controlled to open, so as to avoid the front drive motor and the engine from spinning. The speed difference between the two ends of the synchronizer of the second input shaft is reduced before the synchronizer corresponding to the second input shaft is controlled to engage in gear, which avoids the violent impact between gears caused by gear switching when the speed difference is too large, protects the hybrid transmission and other transmission system components, and achieves smooth gear switching. The front drive motor is controlled to reduce torque before the synchronizer corresponding to the second input shaft engages in gear, which avoids the front drive motor outputting torque in advance, causing the vehicle to move suddenly without being ready, affecting driving safety.

[0119] Figure 4 It is a structural schematic diagram of a device for controlling vehicle reversing provided in an embodiment of the present application.

[0120] The invention is applied to a hybrid vehicle, the vehicle comprises a hybrid transmission, the hybrid transmission comprises: a first input shaft and a second input shaft, the first input shaft is connected to a first clutch, and the second input shaft is connected to a second clutch.

[0121] For example, Figure 4 As shown, the device 400 includes:

[0122] The monitoring module 401 is used to monitor the actual gear position of the gear lever of the vehicle when the actual operation mode of the vehicle is the idle hybrid four-wheel drive mode; wherein, in the idle hybrid four-wheel drive mode, the engine of the vehicle is in an idle state, the first clutch is in a slipping state, the second clutch is in a closed state, the rear drive motor of the vehicle is in a driving state, and the engine drives the front drive motor of the vehicle to rotate so that the front drive motor charges the battery of the vehicle;

[0123] The judgment module 402 is used to judge whether the vehicle meets the preset condition of switching to the idle pure electric four-wheel drive mode when the actual gear position of the gear lever is detected to be switched to the R gear; wherein, in the idle pure electric four-wheel drive mode, the engine of the vehicle is in an idle state, the front drive motor and the rear drive motor of the vehicle are in a driving state, the first clutch and the second clutch are both in an open state, the front drive motor drives the front wheels of the vehicle, and the rear drive motor drives the rear wheels of the vehicle;

[0124] The control module 403 is used to control the actual operation mode of the vehicle to switch from the idle hybrid four-wheel drive mode to the idle pure electric four-wheel drive mode when it is determined that the vehicle meets the preset conditions, so that the vehicle can reverse in the idle pure electric four-wheel drive mode.

[0125] In one possible implementation, the judgment module 402 is specifically used to, when it is monitored that the actual gear position of the gear lever is switched to the R gear, determine whether the vehicle's hybrid transmission includes a mechanical R gear; when the hybrid transmission does not include a mechanical R gear, determine whether the vehicle meets the preset conditions for switching to the idle pure electric four-wheel drive mode.

[0126] In a possible implementation, the control module 403 is specifically configured to control both the first clutch and the second clutch to be opened; and when the second clutch is in an opened state, control the synchronizer corresponding to the second input shaft to be engaged.

[0127] In one possible implementation, the control module 403 is specifically used to control the absolute value of the actual torque of the front drive motor and the absolute value of the actual torque of the engine of the vehicle to decrease; when the absolute value of the actual torque of the front drive motor is less than or equal to the first target torque and the absolute value of the actual torque of the engine is less than or equal to the second target torque, control the first clutch and the second clutch to open.

[0128] In one possible implementation, the control module 403 is specifically used to, when the second clutch is in an open state, adjust the speed of the vehicle's front drive motor according to the rotational speed of the output shaft of the hybrid transmission to reduce the speed difference between the two ends of the synchronizer of the second input shaft; when the speed difference between the two ends of the synchronizer of the second input shaft is less than the preset speed difference, control the synchronizer corresponding to the second input shaft to engage gear.

[0129] In one possible implementation, the control module 403 is specifically used to control the torque of the front-drive motor to be reduced to a third target torque when the speed difference between the two ends of the synchronizer of the second input shaft is less than a preset speed difference; and to control the synchronizer corresponding to the second input shaft to be engaged when the torque of the front-drive motor is equal to the third target torque.

[0130] In one possible implementation, the control module 403 is specifically used to, when the second clutch is in an open state, send a target gear request for the second input shaft to the TCU of the vehicle, and send a shift permission instruction to the TCU and the FMCU of the vehicle, so that after receiving the target gear request and the shift permission instruction of the second input shaft, the TCU sends a speed control activation request and a target speed request to the FMCU; wherein the target speed request includes a target speed, and the target speed is determined based on the speed of the output shaft; after receiving the shift permission instruction and the speed control activation request, the FMCU enters a speed control mode, and after entering the speed control mode and receiving the target speed request, controls the front drive motor to rotate at the target speed to reduce the speed difference between the two ends of the synchronizer of the second input shaft.

[0131] In one possible implementation, the control module 403 is specifically used to control the torque of the front-drive motor to be reduced to a third target torque when the speed difference at both ends of the synchronizer of the second input shaft is less than a preset speed difference, including: when the speed difference at both ends of the synchronizer of the second input shaft is less than the preset speed difference, sending a speed control deactivation request to the FMCU, so that the FMCU switches to the torque control mode after receiving the speed control deactivation request; when it is determined that the FMCU has switched to the torque control mode, controlling the torque of the front-drive motor to be reduced to the third target torque.

[0132] Figure 5 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application.

[0133] For example, Figure 5 As shown, the vehicle 500 includes: a memory 501 and a processor 502, wherein the memory 501 stores an executable program code 5011, and the processor 502 is used to call and execute the executable program code 5011 to perform a method for controlling vehicle reversing.

[0134] 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 execute a method for controlling vehicle reversing provided in an embodiment of the present application.

[0135] 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.

[0136] In the case of dividing each functional module according to each function, the device may also include a monitoring module, a judgment module, 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.

[0137] It should be understood that the device provided in this embodiment is used to execute the above-mentioned method of controlling vehicle reversing, and thus can achieve the same effect as the above-mentioned implementation method.

[0138] 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.

[0139] The processing module may be a processor or a controller, which may implement or execute various exemplary logic blocks, modules and circuits shown in conjunction with the disclosure of the present 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.

[0140] 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 for controlling vehicle reversing provided in the above embodiment.

[0141] 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 method for controlling vehicle reversing provided in the above embodiment.

[0142] This embodiment also provides a computer program product. When the computer program product is run on a computer, the computer executes the above-mentioned related steps to implement a method for controlling vehicle reversing provided in the above embodiment.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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 controlling a vehicle to reverse, 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 method includes: When the actual operation mode of the vehicle is the idle hybrid four-wheel drive mode, the actual gear position of the gear lever of the vehicle is monitored; wherein, in the idle hybrid four-wheel drive mode, the engine of the vehicle is in an idle state, the first clutch is in a slipping state, the second clutch is in a closed state, the rear drive motor of the vehicle is in a driving state, and the engine drives the front drive motor of the vehicle to rotate, so that the front drive motor charges the battery of the vehicle; When it is detected that the actual gear position of the gear lever is switched to the R gear, it is determined whether the vehicle meets the preset condition of switching to the idle pure electric four-wheel drive mode; wherein, in the idle pure electric four-wheel drive mode, the engine of the vehicle is in an idle state, the front drive motor and the rear drive motor of the vehicle are in a driving state, the first clutch and the second clutch are both in an open state, the front drive motor drives the front wheels of the vehicle, and the rear drive motor drives the rear wheels of the vehicle; When it is determined that the vehicle meets the preset conditions, the actual operation mode of the vehicle is controlled to switch from the idle hybrid four-wheel drive mode to the idle pure electric four-wheel drive mode, so that the vehicle reverses in the idle pure electric four-wheel drive mode.

2. The method according to claim 1, characterized in that When it is detected that the actual gear position of the gear lever is switched to the R gear, determining whether the vehicle meets the preset condition for switching to the idle pure electric four-wheel drive mode includes: In the case where it is detected that the actual gear position of the gear lever is switched to the R gear, determining whether the hybrid transmission of the vehicle includes a mechanical R gear; In a case where the hybrid transmission does not include the mechanical R gear, it is determined whether the vehicle meets a preset condition for switching to an idle pure electric four-wheel drive mode.

3. The method according to claim 1 or 2, characterized in that: The controlling the actual operation mode of the vehicle to switch from the idle hybrid four-wheel drive mode to the idle pure electric four-wheel drive mode includes: Controlling the first clutch and the second clutch to be opened; When the second clutch is in an open state, the synchronizer corresponding to the second input shaft is controlled to engage a gear.

4. The method according to claim 3, characterized in that The controlling the first clutch and the second clutch to be opened includes: Controlling the absolute value of the actual torque of the front drive motor of the vehicle and the absolute value of the actual torque of the engine to decrease; When the absolute value of the actual torque of the front drive motor is less than or equal to the first target torque and the absolute value of the actual torque of the engine is less than or equal to the second target torque, the first clutch and the second clutch are controlled to be opened.

5. The method according to claim 3, characterized in that: When the second clutch is in an open state, controlling the synchronizer corresponding to the second input shaft to engage a gear comprises: When the second clutch is in an open state, the front drive motor of the vehicle is adjusted in speed according to the rotation speed of the output shaft of the hybrid transmission to reduce the speed difference between the two ends of the synchronizer of the second input shaft; When the speed difference between the two ends of the synchronizer of the second input shaft is less than the preset speed difference, the synchronizer corresponding to the second input shaft is controlled to engage a gear.

6. The method according to claim 5, characterized in that When the speed difference between the two ends of the synchronizer of the second input shaft is less than a preset speed difference, controlling the synchronizer corresponding to the second input shaft to engage a gear comprises: When the speed difference between the two ends of the synchronizer of the second input shaft is less than the preset speed difference, controlling the torque of the front drive motor to be reduced to a third target torque; When the torque of the front-drive motor is equal to the third target torque, the synchronizer corresponding to the second input shaft is controlled to engage gear.

7. The method according to claim 5, characterized in that When the second clutch is in an open state, the front drive motor of the vehicle is adjusted according to the rotation speed of the output shaft of the hybrid transmission to reduce the speed difference between the two ends of the synchronizer of the second input shaft, including: When the second clutch is in an open state, a target gear position request for the second input shaft is sent to the TCU of the vehicle, and a shift permission instruction is sent to the TCU and the FMCU of the vehicle, so that after receiving the target gear position request for the second input shaft and the shift permission instruction, the TCU sends a speed control activation request and a target speed request to the FMCU; wherein the target speed request includes a target speed, and the target speed is determined based on the speed of the output shaft; After receiving the shift permission instruction and the speed control activation request, the FMCU enters the speed control mode, and after entering the speed control mode and receiving the target speed request, controls the front drive motor to rotate according to the target speed to reduce the speed difference between the two ends of the synchronizer of the second input shaft.

8. The method according to claim 7, characterized in that When the speed difference between the two ends of the synchronizer of the second input shaft is less than the preset speed difference, controlling the torque of the front drive motor to be reduced to the third target torque includes: When the speed difference between the two ends of the synchronizer of the second input shaft is less than the preset speed difference, a speed control deactivation request is sent to the FMCU, so that the FMCU switches to the torque control mode after receiving the speed control deactivation request; When it is determined that the FMCU is switched to the torque control mode, the torque of the front drive motor is controlled to be reduced to a third target torque.

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 8.

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 8 is implemented.

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