Gear switching method, vehicle and storage medium

Abstract

The invention provides a gear switching method, a vehicle and a storage medium, the method is applied to the technical field of hybrid power control, and the method comprises the steps that in the process that the vehicle runs based on a direct drive mode, if it is determined that the vehicle needs to switch gears, the whole vehicle driving power corresponding to the direct drive mode and the discharging power of a power battery are determined; based on the whole vehicle driving power, the discharging power and the gear change state of the vehicle, a target torque reduction gradient is determined; based on the target torque reduction gradient, the actual torque of the engine is controlled to be reduced to the target torque; and under the condition that the actual torque of the engine is equal to the target torque, the clutch is controlled to be in an open state, so that the vehicle is shifted under the condition that the clutch is in the open state. The method can ensure that the power is not interrupted in the vehicle gear shifting process, the vehicle stability is improved, and the user driving experience is improved.

Description

Technical Field

[0001] This application relates to the field of hybrid power control technology, and more specifically, to a gear shifting method, vehicle, and storage medium in the field of hybrid power control technology. Background Technology

[0002] As the automotive industry shifts towards "low-carbon" and "electrification," hybrid vehicles are gaining popularity due to their dual advantages of fuel economy and extended range. Because electric motors offer fast torque response, high control precision (capable of millisecond-level torque adjustment), and smooth, non-jerk-free output, they are typically used in hybrid vehicles to adjust the speed and torque at the transmission input during gear shifting.

[0003] However, in some hybrid vehicles that use a rigid connection between the motor and the gearbox input shaft, the lack of a buffer mechanism and the direct rigid connection between the motor and the gearbox input shaft can easily lead to a short-term power interruption during gear shifting, resulting in a poor driving experience. Summary of the Invention

[0004] This application provides a gear shifting method, a vehicle, and a storage medium. The method ensures uninterrupted power during gear shifting, improves vehicle stability, and enhances the user's driving experience.

[0005] Firstly, a gear shifting method is provided, comprising: when the vehicle is driving in direct drive mode, if it is determined that the vehicle needs to shift gears, determining the vehicle drive power and the power battery discharge power corresponding to the direct drive mode; determining a target torque reduction gradient based on the vehicle drive power, discharge power, and the vehicle's gear shifting state; controlling the engine's actual torque to decrease to the target torque based on the target torque reduction gradient; and controlling the clutch to be in an open state when the engine's actual torque equals the target torque, so that the vehicle shifts gears when the clutch is in an open state.

[0006] In the above technical solution, when it is determined that the vehicle needs to shift gears during direct drive mode, it can be confirmed that the vehicle is experiencing power loss due to gear shifting. At this point, a target torque reduction gradient is determined based on the vehicle's drive power in direct drive mode, the battery's discharge power, and the vehicle's gear shift status. Based on this target torque reduction gradient, the engine can be controlled to reduce torque to the target level at a certain gradient, avoiding power loss caused by the engine torque dropping directly to zero during gear shifting and ensuring the smoothness of the shifting process. Considering multiple parameters such as the vehicle's drive power in direct drive mode, the battery's discharge power, and the vehicle's gear shift status to determine the target torque reduction gradient improves the accuracy of torque reduction during gear shift control.

[0007] In conjunction with the first aspect, in some possible implementations, a target torque reduction gradient is determined based on the vehicle's driving power, discharge power, and gear shift state. This includes: determining a first torque reduction gradient as the target torque reduction gradient when the vehicle's driving power is less than or equal to the discharge power and the vehicle is in an upshift state; determining a second torque reduction gradient as the target torque reduction gradient when the vehicle's driving power is less than or equal to the discharge power and the vehicle is in a downshift state; wherein the first torque reduction gradient is less than the second torque reduction gradient; determining a third torque reduction gradient as the target torque reduction gradient when the vehicle's driving power is greater than the discharge power and the vehicle is in an upshift state; wherein the third torque reduction gradient is less than the first torque reduction gradient; and determining a fourth torque reduction gradient as the target torque reduction gradient when the vehicle's driving power is greater than the discharge power and the vehicle is in a downshift state; wherein the fourth torque reduction gradient is less than the second torque reduction gradient and greater than the third torque reduction gradient.

[0008] In the above technical solution, by analyzing the relationship between the vehicle's driving power and the power battery's discharge power, the power range for low power demand (where the vehicle's driving power is less than or equal to the power battery's discharge power) and the power range for high power demand (where the vehicle's driving power is greater than the power battery's discharge power) can be determined. Based on these power ranges and the two gear shift states (upshifting and downshifting), four scenarios are defined. The torque reduction gradient in each scenario is then defined as the target torque reduction gradient, achieving refined control of the target torque reduction gradient based on the current scenario's demand. Specifically, a larger torque reduction gradient corresponds to the low power demand range, enabling rapid gear shifting and preventing the vehicle from entering the high power demand range. A smaller torque reduction gradient corresponds to the high power demand range, enabling smooth gear shifting and ensuring power continuity, thus avoiding power interruption caused by the engine torque dropping directly from high torque to zero. A smaller torque reduction gradient corresponds to upshifting, preventing excessive power loss that could affect driving comfort. A larger torque reduction gradient corresponds to downshifting, enabling rapid gear shifting.

[0009] Combining the first aspect and the above implementation methods, in some possible implementation methods, the target torque reduction gradient is determined based on the vehicle's driving power, discharge power, and the vehicle's gear change state. This includes: obtaining the engine's original air circuit torque request value and the current opening of the vehicle's accelerator pedal; determining the target correspondence based on the vehicle's driving power, discharge power, and the vehicle's gear change state; and finding the target correspondence based on the original air circuit torque request value, accelerator pedal opening, vehicle driving power, and discharge power to obtain the target torque reduction gradient.

[0010] In the above technical solution, the power range can be determined by the relationship between the vehicle's driving power and the power battery's discharge power. Different scenarios can be determined based on the power demand range and gear change status. The vehicle's driving power, discharge power, and gear change status can determine the target correspondence with the current scenario, thereby determining the target torque reduction gradient. This achieves refined control of the target torque reduction gradient based on the demand under the current scenario, improving the reliability of torque reduction control.

[0011] Combining the first aspect and the above implementation methods, in some possible implementation methods, the target correspondence includes a first correspondence and a second correspondence. The target torque reduction gradient is obtained by finding the target correspondence based on the original air circuit torque request value, accelerator pedal opening, vehicle drive power, and discharge power. This includes: calculating the power difference between the vehicle drive power and the discharge power; finding the first correspondence based on the original air circuit torque request value and the power difference to obtain the basic torque reduction gradient; finding the second correspondence based on the accelerator pedal opening and the power difference to obtain the first target correction coefficient; and determining the target torque reduction gradient based on the basic torque reduction gradient and the first target correction coefficient.

[0012] In the above technical solution, when determining the basic torque reduction gradient, the power difference and the original air circuit torque request value are considered. The power difference reflects the relationship between the vehicle's driving power and the power battery's discharge power, thus indicating the possibility of over-discharge of the power battery. A larger power difference indicates a greater risk of over-discharge, ensuring that the determined basic torque reduction gradient avoids this situation. The original air circuit torque request value characterizes the engine's high-load operating state, ensuring that the determined basic torque reduction gradient avoids high engine load. The accelerator pedal opening represents the power demand. Based on the accelerator pedal opening and the power difference, a first target correction coefficient is determined to adjust the basic torque reduction gradient, ensuring that the target torque reduction gradient takes into account the vehicle's current power demand, further improving the accuracy of torque reduction control.

[0013] Combining the first aspect and the above implementation methods, in some possible implementation methods, the target torque reduction gradient includes the target fire path torque reduction gradient and the target gas path torque reduction gradient. The target torque reduction gradient is determined based on the basic torque reduction gradient and the first target correction coefficient, including: multiplying the basic torque reduction gradient and the first target correction coefficient to obtain the target fire path torque reduction gradient; correcting the target fire path torque reduction gradient based on the second target correction coefficient to obtain the target gas path torque reduction gradient; wherein the target fire path torque reduction gradient is greater than the target gas path torque reduction gradient; the second target correction coefficient is used to control the absolute value of the torque difference between the reduced fire path torque and the reduced gas path torque to be less than or equal to a preset difference.

[0014] In the above technical solution, by determining the target fire circuit torque reduction gradient and the target air circuit torque reduction gradient, it is possible to control the torque reduction of both the fire circuit torque and the air circuit torque of the engine. The second target correction coefficient can make the torque difference between the reduced fire circuit torque and the reduced air circuit torque less than or equal to the preset difference, ensuring that the problem of high fuel consumption will not occur due to the separation of the air circuit and the fire circuit during the torque reduction process, thereby improving the fuel economy of the vehicle during the gear shifting process.

[0015] Combining the first aspect and the above implementation methods, in some possible implementation methods, the target torque includes the target fire circuit torque and the target air circuit torque. The target torque is determined by the following methods: determining the original air circuit torque request value based on the driver's required torque, the target front and rear axle torque distribution ratio, and the actual torque of the target motor; determining the target fire circuit torque based on the original air circuit torque request value, the shift intervention torque, and the engine fire circuit speed control torque; and determining the target air circuit torque based on the original air circuit torque request value, the engine air circuit torque reserve, the engine air circuit speed control torque reserve, and the target fire circuit torque.

[0016] In the above technical solution, based on the original air circuit torque request value, shift intervention torque, and engine fire circuit speed control torque, the engine's target fire circuit torque can be dynamically calculated in real time. Simultaneously considering the engine fire circuit speed control torque, it ensures that the engine maintains a certain speed when the clutch is open, avoiding engine damage caused by excessively high or low engine speeds. Calculating the target air circuit torque based on the original air circuit torque, the engine air circuit reserved torque, the engine air circuit speed control reserved torque, and the target fire circuit torque ensures that a portion of the engine air circuit torque is reserved, guaranteeing that the target air circuit torque is not less than the target fire circuit torque and fluctuates with the target fire circuit torque, thus ensuring the accuracy of target torque control.

[0017] Combining the first aspect and the above implementation methods, in some possible implementation methods, the target torque reduction gradient includes the target fire path torque reduction gradient and the target air path torque reduction gradient, the target torque includes the target fire path torque and the target air path torque, the target air path torque is greater than the target fire path torque, and based on the target torque reduction gradient, controlling the engine's actual torque to reduce to the target torque includes: controlling the engine's fire path torque to reduce to the target fire path torque according to the target fire path torque reduction gradient; during the process of controlling the engine's fire path torque to reduce according to the target fire path torque reduction gradient, controlling the engine's air path torque to reduce to the target air path torque according to the target air path torque reduction gradient, so as to ensure that the absolute value of the torque difference between the reduced fire path torque and the reduced air path torque is less than or equal to a preset difference, and to ensure that the engine's ignition angle is within the target adjustment range.

[0018] In conjunction with the first aspect and the above implementation methods, in some possible implementation methods, the method further includes: if the controlled firing torque of the engine, after being reduced according to the target firing torque reduction gradient, does not reach the target firing torque, then based on the target firing torque and the target torque range of a single cylinder, determining the target number of cylinders to be deactivated in the engine; wherein the target torque range of a single cylinder is determined based on the target adjustment range of the ignition angle; and performing cylinder deactivation processing on the cylinders corresponding to the target number of cylinders to be deactivated, so that the firing torque is reduced to the target firing torque value.

[0019] In the aforementioned technical solution, when the method of reducing the torque in the firing circuit through the target firing circuit torque reduction gradient fails to reduce the firing circuit torque to the target firing circuit torque, the target number of cylinders to be cut off in the engine can be accurately determined based on the target firing circuit torque and the target torque range of a single cylinder. This ensures that the single-cylinder torque of the remaining cylinders after cylinder cut-off remains within the compliant range, avoiding combustion instability caused by excessive torque reduction. Then, cylinder cut-off processing is performed on the cylinders corresponding to the target number of cylinders to be cut off in the engine. By reducing the number of cylinders that effectively perform power in the engine, the engine torque output is directly reduced, ultimately allowing the firing circuit torque to be precisely reduced to the target firing circuit torque. This ensures successful torque reduction control of the engine, facilitating subsequent clutch engagement for gear shifting.

[0020] In conjunction with the first aspect and the above implementation methods, in some possible implementation methods, after the control clutch is in the open state so that the vehicle can shift gears while the clutch is in the open state, the method further includes: when the vehicle completes gear shifting, controlling the speed difference between the two ends of the clutch to decrease; when the speed difference between the two ends of the clutch is less than or equal to a preset speed difference, controlling the clutch to be in the closed state; when the clutch is in the closed state, determining a target torque increase gradient; and controlling the actual torque of the engine to increase based on the target torque increase gradient so that the engine drives the vehicle.

[0021] In the aforementioned technical solution, controlling the transmission to switch to the target gear corresponding to the direct drive mode after the clutch is engaged establishes the mechanical transmission foundation for direct drive mode in advance, preparing for subsequent power path switching and facilitating precise vehicle control in direct drive mode. Furthermore, when the speed difference between the clutch ends is less than or equal to a preset speed difference, the clutch is controlled to be engaged. Synchronizing the speeds at both ends of the clutch eliminates mechanical shock during engagement, ensuring safe and smooth clutch closure and preventing shifting jerks or component wear caused by excessive speed differences. With the clutch engaged, the actual engine torque is increased based on the target torque gradient, allowing engine power to be smoothly transmitted to the wheels through the engaged clutch and the gearbox, switching the vehicle's drive mode from series mode to direct drive mode without interrupting power during the transition.

[0022] Combining the first aspect and the above implementation methods, in some possible implementation methods, determining the target torque increase gradient includes: obtaining the current engine speed, current engine torque, clutch pressure, accelerator pedal opening, and current vehicle speed; determining the basic torque increase gradient based on the current engine speed and current engine torque; determining the first correction coefficient based on the current engine torque and clutch pressure; determining the second correction coefficient based on the accelerator pedal opening and current vehicle speed; and determining the target torque increase gradient by combining the basic torque increase gradient, the first correction coefficient, and the second correction coefficient.

[0023] In the above technical solution, after determining the basic torque increase gradient based on the current engine speed and torque, the basic torque increase gradient is further dynamically corrected by combining the current engine torque, clutch pressure, accelerator pedal opening, and vehicle speed to finally obtain the target torque increase gradient. Determining the basic torque increase gradient first, and then correcting it based on multi-dimensional factors, fully considers various factors affecting the torque increase process. This allows for matching different target torque increase gradients for different operating conditions and avoids torque fluctuations caused by a single factor through the optimization of multiple parameters, thereby ensuring the smoothness of the torque increase process under various operating conditions.

[0024] Secondly, a gear shifting device is provided, comprising: a first determining module, configured to determine the vehicle drive power and the power battery discharge power corresponding to the direct drive mode if it is determined that the vehicle needs to shift gears during direct drive mode operation; a second determining module, configured to determine a target torque reduction gradient based on the vehicle drive power, discharge power, and the vehicle's gear shift state; a first control module, configured to control the engine's actual torque to decrease to the target torque based on the target torque reduction gradient; and a second control module, configured to control the clutch to be in an open state when the engine's actual torque equals the target torque, so that the vehicle shifts gears when the clutch is in an open state.

[0025] In conjunction with the second aspect, in some possible implementations, the second determining module is specifically used to: determine a first torque reduction gradient as the target torque reduction gradient when the vehicle's driving power is less than or equal to the discharge power and the vehicle's gear shift state is upshifting; determine a second torque reduction gradient as the target torque reduction gradient when the vehicle's driving power is less than or equal to the discharge power and the vehicle's gear shift state is downshifting; wherein the first torque reduction gradient is less than the second torque reduction gradient; determine a third torque reduction gradient as the target torque reduction gradient when the vehicle's driving power is greater than the discharge power and the vehicle's gear shift state is upshifting; wherein the third torque reduction gradient is less than the first torque reduction gradient; determine a fourth torque reduction gradient as the target torque reduction gradient when the vehicle's driving power is greater than the discharge power and the vehicle's gear shift state is downshifting; wherein the fourth torque reduction gradient is less than the second torque reduction gradient and greater than the third torque reduction gradient.

[0026] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the second determining module is specifically used to: obtain the original air circuit torque request value of the engine and the current opening of the vehicle's accelerator pedal; determine the target correspondence based on the vehicle's driving power, discharge power and the vehicle's gear change state; and find the target correspondence based on the original air circuit torque request value, accelerator pedal opening, vehicle driving power and discharge power to obtain the target torque reduction gradient.

[0027] Combining the second aspect and the above implementation methods, in some possible implementation methods, the target correspondence includes a first correspondence and a second correspondence. The second determining module is specifically used for: calculating the power difference between the vehicle's driving power and the discharge power; finding the first correspondence based on the original air circuit torque request value and the power difference to obtain the basic torque reduction gradient; finding the second correspondence based on the accelerator pedal opening and the power difference to obtain the first target correction coefficient; and determining the target torque reduction gradient based on the basic torque reduction gradient and the first target correction coefficient.

[0028] Combining the second aspect and the above implementation methods, in some possible implementation methods, the second determining module is specifically used to: multiply the basic torque reduction gradient and the first target correction coefficient to obtain the target fire path torque reduction gradient; based on the second target correction coefficient, correct the target fire path torque reduction gradient to obtain the target gas path torque reduction gradient; wherein, the target fire path torque reduction gradient is greater than the target gas path torque reduction gradient; the second target correction coefficient is used to control the absolute value of the torque difference between the reduced fire path torque and the reduced gas path torque to be less than or equal to a preset difference.

[0029] In conjunction with the second aspect and the above-described implementation methods, in some possible implementation methods, the device further includes: a third determining module, used to determine the original air circuit torque request value based on the driver's required torque, the target front and rear axle torque distribution ratio, and the actual torque of the target motor; to determine the target fire circuit torque based on the original air circuit torque request value, the shift intervention torque, and the engine fire circuit speed control torque; and to determine the target air circuit torque based on the original air circuit torque request value, the engine air circuit torque reserve, the engine air circuit speed control torque reserve, and the target fire circuit torque.

[0030] Combining the second aspect and the above implementation methods, in some possible implementation methods, the target torque reduction gradient includes the target fire path torque reduction gradient and the target air path torque reduction gradient, the target torque includes the target fire path torque and the target air path torque, and the target air path torque is greater than the target fire path torque. The first control module is specifically used to: control the engine's fire path torque to decrease to the target fire path torque according to the target fire path torque reduction gradient; during the process of controlling the engine's fire path torque to decrease according to the target fire path torque reduction gradient, control the engine's air path torque to decrease to the target air path torque according to the target air path torque reduction gradient, so as to ensure that the absolute value of the torque difference between the reduced fire path torque and the reduced air path torque is less than or equal to a preset difference, and to ensure that the engine's ignition angle is within the target adjustment range.

[0031] In conjunction with the second aspect and the above implementation methods, in some possible implementation methods, the device further includes: a third control module, used to determine the target number of cylinders to be cut off in the engine based on the target fire torque and the target torque range of a single cylinder if the fire torque of the engine after being reduced according to the target fire torque reduction gradient does not reach the target fire torque; wherein the target torque range of a single cylinder is determined based on the target adjustment range of the ignition angle; and to perform cylinder cut-off processing on the cylinders corresponding to the target number of cylinders to be cut off in the engine so that the fire torque is reduced to the target fire torque value.

[0032] In conjunction with the second aspect and the above implementation methods, in some possible implementation methods, the device further includes: a fourth control module, used to control the speed difference between the two ends of the clutch to decrease when the vehicle completes gear shifting; control the clutch to be in a closed state when the speed difference between the two ends of the clutch is less than or equal to a preset speed difference; determine a target torque increase gradient when the clutch is in a closed state; and control the actual torque of the engine to increase based on the target torque increase gradient so that the engine drives the vehicle.

[0033] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the fourth control module is specifically used to: acquire the current engine speed, the current engine torque, the clutch pressure, the accelerator pedal opening, and the current vehicle speed; determine the basic torque increase gradient based on the current engine speed and the current engine torque; determine the first correction coefficient based on the current engine torque and the clutch pressure; determine the second correction coefficient based on the accelerator pedal opening and the current vehicle speed; and determine the target torque increase gradient by combining the basic torque increase gradient, the first correction coefficient, and the second correction coefficient.

[0034] Thirdly, a vehicle is provided, including 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, causing the vehicle to perform the methods of the first aspect or any possible implementation thereof.

[0035] Fourthly, a computer program product is provided, comprising: computer program code, which, when run on a computer, causes the computer to perform the methods described in the first aspect or any possible implementation thereof.

[0036] Fifthly, a computer-readable storage medium is provided that stores computer program code, which, when executed on a computer, causes the computer to perform the methods described in the first aspect or any possible implementation thereof. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the architecture of a hybrid vehicle provided in an embodiment of this application.

[0038] Figure 2 This is a schematic flowchart of a method for controlling a vehicle provided in an embodiment of this application.

[0039] Figure 3 This is a schematic diagram of the control process for switching gears in direct drive mode provided in an embodiment of this application.

[0040] Figure 4This is a schematic diagram of the structure of a gear switching device provided in an embodiment of this application.

[0041] Figure 5 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application. Detailed Implementation

[0042] The technical solutions in this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0043] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting 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 that feature.

[0044] As the automotive industry shifts towards "low-carbon" and "electrification," hybrid vehicles are gaining popularity due to their dual advantages of fuel economy and extended range. Because electric motors offer fast torque response, high control precision (capable of millisecond-level torque adjustment), and smooth, non-jerk-free output, they are typically used in hybrid vehicles to adjust the speed and torque at the transmission input during gear shifting.

[0045] However, in some hybrid vehicles that use a rigid connection between the motor and the gearbox input shaft, the lack of a buffer mechanism and the direct rigid connection between the motor and the gearbox input shaft can easily lead to a short-term power interruption during gear shifting, resulting in a poor driving experience.

[0046] Figure 1 This is a schematic diagram of the architecture of a hybrid vehicle provided in an embodiment of this application.

[0047] For example, such as Figure 1 As shown, the architecture corresponding to the hybrid vehicle 100 is an example of an architecture with a "rigid connection between the motor and the input shaft of the gearbox".

[0048] The hybrid vehicle 100 includes: an engine 101, a clutch 102, a front drive motor 103, a gearbox 104, a rear drive motor 105, a power battery 106, a left front wheel 1071, a right front wheel 1072, a left rear wheel 1081, and a right rear wheel 1082.

[0049] The engine 101 is one of the vehicle's power sources, generating power by burning fuel (such as gasoline or diesel). The power generated by the engine is transmitted through the crankshaft to the clutch 102 and the gearbox 104, ultimately driving the front wheels of the hybrid vehicle 100.

[0050] Clutch 102 is used to disconnect or connect the mechanical connection between engine 101 and transmission 104. Clutch 102 has two states: open and closed. When clutch 102 is in the open state, the connection between engine 101 and transmission 104 is disconnected; even if engine 101 is running, the power it generates will not be transmitted to transmission 104. When clutch 102 is in the closed state, the mechanical connection between engine 101 and transmission 104 is established, and the power generated by engine 101 can be transmitted to transmission 104.

[0051] The front drive motor 103, also called the P2 motor, can be rigidly connected to the input shaft of the gearbox 104. The front drive motor 103 is used to drive the front wheels of the vehicle through the gearbox 104, and the front drive motor 103 can also function as a generator.

[0052] As one embodiment, when the front drive motor 103 is working as a generator, the clutch 102 is in a closed state, and the engine 101 transmits power through the clutch 102 and the gearbox 104 to drive the front drive motor 103 to generate electricity.

[0053] The transmission 104 is located on the front axle of the vehicle and can also be called a front axle transmission. The transmission 104 is used to change the speed and torque output by the engine 101 to adapt to different driving conditions and ensure that the vehicle operates efficiently under different speed and load conditions.

[0054] The rear drive motor 105, also known as the P4 motor, drives the rear wheels of the vehicle when it is running.

[0055] The power battery 106, also known as a high-voltage battery, supplies power to the front drive motor 103 and the rear drive motor 105 so that the front drive motor 103 and the rear drive motor 105 can output torque to drive the vehicle.

[0056] When the engine 101 drives the front drive motor 103 to generate electricity, the electrical energy generated by the front drive motor 103 can also charge the power battery 106; or, the electrical energy generated by the front drive motor 103 can be directly supplied to the rear drive motor 105 so that the rear drive motor 105 can drive the vehicle.

[0057] It is understandable that the above Figure 1 As an example only, the above-mentioned "rigid connection between motor and gearbox input shaft" architecture can also be other architectures, and the specific design of the architecture is not limited in the embodiments of this application.

[0058] Furthermore, if a rigid connection is established between the front drive motor 103 and the input shaft of the gearbox 104, it means that they are equivalent to the same rotating component; if one rotates, the other will inevitably rotate at the same speed. Conversely, if the speed of one component is to be controlled, the speed of the other component must be controlled synchronously. Since the gearbox 104's shifting action is usually achieved by controlling the speed of the gearbox input shaft, when the input shaft of the front drive motor 103 and the gearbox 104 are rigidly connected, the front drive motor 103 must assume the function of gearbox shifting.

[0059] Specifically, in traditional gasoline-powered vehicles, when shifting gears, the clutch is usually disengaged first (decoupling the engine and transmission), allowing the transmission input shaft to lose power and freely decelerate or accelerate, before shifting gears (no-load shifting to avoid gear grinding) to complete the shift. However, in... Figure 1 In the hybrid vehicle 100 shown, because the front drive motor 103 is rigidly connected to the input shaft of the gearbox 104, the input shaft of the gearbox 104 cannot rotate freely. The front drive motor 103 needs to actively control the speed of the input shaft in order to match the "gear speed corresponding to the target gear" and thus complete the gear shifting operation.

[0060] Furthermore, with a rigid connection between the front drive motor 103 and the input shaft of the gearbox 104, any force acting on the input shaft of the gearbox 104 (such as power transmitted by the engine through the clutch) will directly affect the front drive motor 103. Therefore, if a mode switching request is received, it is typically necessary to decouple the engine 101 from the front drive motor 103, thereby controlling the engine and motor independently, i.e., controlling the clutch 102 to open.

[0061] The inventors of this application discovered through research that, when the front-drive motor and the input shaft of the transmission are rigidly connected, if the vehicle needs to shift gears while driving in direct-drive mode, it typically requires disengaging the clutch. Disengaging the clutch usually cuts off the power path from the engine to the clutch to the transmission input shaft, preventing the engine from driving the front-drive motor to generate electricity. The front-drive motor then relies solely on the battery for power to drive the vehicle. Therefore, with the clutch open, if the battery is depleted, both the front-drive and rear-drive motors will lose power, resulting in a power interruption during gear shifting.

[0062] To address the aforementioned technical problems, this application provides a gear shifting method. The method is executed by a vehicle, specifically a controller within the vehicle. This method determines a target torque reduction gradient based on the vehicle's driving power, the power battery's discharge power, and the gear shift state. It then reduces engine torque according to this target torque reduction gradient, achieving a smooth torque reduction during gear shifting and thus avoiding power interruption caused by the engine torque dropping directly to zero.

[0063] Figure 2 This is a schematic flowchart of a method for controlling a vehicle provided in an embodiment of this application.

[0064] For example, such as Figure 2 As shown, the method 200 includes:

[0065] Step 201: During the process of the vehicle driving in direct drive mode, if it is determined that the vehicle needs to switch gears, then determine the vehicle drive power and the discharge power of the power battery corresponding to the direct drive mode.

[0066] Step 202: Determine the target torque reduction gradient based on the vehicle's driving power, discharge power, and gear shift status.

[0067] Step 203: Based on the target torque reduction gradient, control the engine's actual torque to reduce to the target torque;

[0068] Step 204: When the actual torque of the engine is equal to the target torque, control the clutch to be in the open state so that the vehicle can shift gears when the clutch is in the open state.

[0069] exist Figure 2 In the illustrated embodiment, when it is determined that the vehicle needs to shift gears during direct drive mode, it can be determined that the vehicle is currently experiencing power loss due to gear shifting. At this point, a target torque reduction gradient is determined based on the vehicle's overall drive power in direct drive mode, the battery's discharge power, and the vehicle's gear shift status. Based on this target torque reduction gradient, the engine can be controlled to reduce torque to the target torque at a certain gradient, avoiding power loss caused by the engine torque dropping directly to zero during gear shifting, thus ensuring the smoothness of the shifting process. Considering multiple parameters such as the vehicle's overall drive power in direct drive mode, the battery's discharge power, and the vehicle's gear shift status to determine the target torque reduction gradient improves the accuracy of torque reduction during gear shift control.

[0070] The following is about Figure 2 The specific implementation methods of each step in the illustrated embodiments are explained in detail below:

[0071] In step 201, direct drive mode refers to the engine directly driving the wheels through a mechanical transmission path, with the electric motor either participating or not. When the electric motor is not participating, the engine's speed and torque act directly on the wheels, similar to the drive system of a traditional gasoline-powered vehicle. When the electric motor is participating, it can function as both a drive motor and a generator. Specifically, when the vehicle requires high torque output and the engine's torque output is insufficient, both the engine and the electric motor act as drive sources to propel the wheels; in this case, the electric motor functions as a drive motor. Conversely, when the vehicle's torque output requirement is low, the engine's torque output can not only drive the wheels but also power the electric motor to generate electricity, charging the battery or supplying power to the vehicle's electrical system; in this case, the electric motor functions as a generator.

[0072] In the direct drive mode described above, when the motor is involved in the operation, it can also be called "parallel mode." In other words, parallel mode is a special type of direct drive mode.

[0073] Figure 1 The transmission of the vehicle shown typically includes multiple gears, each corresponding to a different speed range. When driving in direct drive mode, a gear shift will be triggered when the vehicle speed increases or decreases to the speed range corresponding to a gear other than the current one. This indicates that the vehicle is in direct drive mode and a gear shift is required.

[0074] For example, the vehicle's current actual gear is 1st gear, corresponding to a speed range of 0 kph (km / h) to 60 kph. The speed range for 2nd gear is 50 kph to 120 kph. When the vehicle speed is detected to be greater than 50 kph, it is determined that the vehicle speed has increased to the speed range corresponding to 2nd gear, at which point the vehicle will adjust its target gear to 2nd. Based on the difference between the actual gear and the target gear, it can be determined that the vehicle needs to shift gears.

[0075] Furthermore, if it is determined that the vehicle needs to switch gears in direct drive mode, in order to ensure the smoothness of the gear shifting process under different driving conditions, the vehicle's total drive power and the power battery discharge power in direct drive mode can be calculated. Based on the above parameters, the current driving condition can be determined, and different torque reduction strategies can be matched according to different driving conditions to achieve smooth gear shifting.

[0076] In direct drive mode, the vehicle can be driven by the front drive motor, the rear drive motor, and the engine. The total drive power of the vehicle in direct drive mode refers to the mechanical power provided by the front drive motor, the rear drive motor, and the engine to drive the vehicle forward, and the unit is kilowatt (KW).

[0077] As one implementation method, after determining that the vehicle needs to switch gears, the current output torque of the rear drive motor, the current output torque of the front drive motor, the current output torque of the engine, the average wheel speed of the vehicle, and the conversion efficiency between electric power and drive mechanical power can be obtained. Based on the current output torque of the rear drive motor, the current output torque of the front drive motor, the current output torque of the engine, the average wheel speed of the vehicle, and the conversion efficiency between electric power and drive mechanical power, the total vehicle drive power in direct drive mode can be calculated.

[0078] Torque sensors can be installed in the rear drive motor, front drive motor, and engine to obtain the torque collected by the current torque sensor, and thus obtain the current output torque of the rear drive motor, the current output torque of the front drive motor, and the current output torque of the engine.

[0079] A vehicle typically consists of four wheels, each equipped with a wheel speed sensor. The sensor measures the wheel speed of each wheel, and the average wheel speed is calculated to obtain the vehicle's average wheel speed.

[0080] The calculation process for the vehicle's drive power in direct drive mode includes: adding the current output torque of the rear drive motor, the current output torque of the front drive motor, and the current output torque of the engine to obtain the total output torque; multiplying the total output torque by the vehicle's average wheel speed to obtain the total output electric power; and dividing the total output electric power by the conversion efficiency to obtain the vehicle's drive power. The formula for calculating the vehicle's drive power is shown in the following formula (1):

[0081]

[0082] In the above formula (1), P D For the total vehicle drive power, T p4 T represents the current output torque of the rear drive motor. p2 T represents the current output torque of the front drive motor. eng N is the current output torque of the engine, N is the average wheel speed of the vehicle, η is the conversion efficiency, and 9550 is a unit conversion factor used to convert the unit NM (Newton-meter) and the unit rpm (revolutions per minute) to the unit KW. "100" is related to the conversion efficiency η, and the unit of η is "%". When only the value corresponding to η is substituted into the above formula (2) (for example, if η is 80%, only the value "80" can be substituted into the formula (2)), multiplying the above formula by "100" can make the final calculated vehicle driving power P D The conversion efficiency η was still taken into account.

[0083] For example, the current output torque T of the rear drive motor p4 The current output torque T of the front drive motor is 70 NM. p2The current output torque T of the engine is 30 Nm. eng Given a torque of 50 Nm, an average wheel speed N of 3000 rpm, and a conversion efficiency η of 80%, the vehicle's current total output torque can be calculated as T. p4 +T p2 +T eng =70+30+50=150NM, then the total vehicle drive power P D =((150*3000) / 9550) / 80*100≈58.9KW.

[0084] The discharge power of the aforementioned power battery refers to the electrical power currently output by the power battery for driving purposes, and the unit is KW.

[0085] For example, the discharge power of the aforementioned power battery can be calculated using the following formula:

[0086] P B =P L -P H -P R (2)

[0087] In the above formula (2), P B This refers to the discharge power (in kW) of the aforementioned power battery; P L This refers to the long-term discharge power of the power battery (unit: kW); P H This refers to the power consumption (in kW) of high-voltage accessories in a vehicle; P R This refers to the reserved power for the vehicle's drive system (in kW).

[0088] Specifically, the above P L This can usually be calculated by the vehicle's Battery Management System (BMS) based on the battery's actual operating parameters; the aforementioned P H Typically, the power consumption of each high-voltage accessory in the vehicle, collected by sensors, can be summed to obtain the value; the aforementioned P R Typically, this can be determined by the vehicle's controller based on real-time vehicle status (such as vehicle speed, acceleration, battery level, remaining driving range, etc.).

[0089] For example, the long-term discharge power P of the power battery L The power consumption P of the high-voltage accessory is 100KW. H 10KW; Reserved vehicle drive power P R For 5KW, the above P L For 100KW, P H For 10KW, P RSubstituting 5KW into formula (2) above, the discharge power P of the power battery can be calculated. B =100-10-5=85KW.

[0090] When the vehicle is driving in direct drive mode, and it is determined that the vehicle needs to switch gears, the total vehicle drive power and the discharge power of the power battery corresponding to the direct drive mode can be calculated using the above formulas (1) and (2).

[0091] In step 202, the discharge power of the power battery can be understood as the total output power that the vehicle can currently output; the aforementioned vehicle drive power can be understood as the current power demand of the vehicle; and the gear change state specifically refers to the state of the gear change trend. Based on the relationship between the vehicle's total output power and the power demand, the level of the vehicle's current power demand can be determined. Based on the gear change trend, the change in power demand can be further determined, which facilitates the subsequent determination of which strategy to use for torque reduction operation before gear shifting based on the level and change of power demand.

[0092] Specifically, the target range of the vehicle's driving power can be determined based on the relationship between the vehicle's total output power (i.e., the sum of the power battery's discharge power and the target motor's power generation power) and the required power (i.e., the vehicle's driving power).

[0093] The target range mentioned above may include a low power demand range and a high power demand range.

[0094] When the vehicle's driving power is less than or equal to the power battery's discharge power, it means that the power battery's discharge power meets the vehicle's current driving needs. The vehicle's current power demand is low, which means that the vehicle's driving power is in the low power demand range.

[0095] When the vehicle's driving power is greater than the power battery's discharge power but less than or equal to the vehicle's total output power, it means that the sum of the power battery's discharge power and the target motor's power generation power is needed to meet the vehicle's current driving requirements. This indicates that the vehicle's current power requirement is high, meaning that the vehicle's driving power is in the high power requirement range.

[0096] Gear shift status specifically refers to the trend of gear changes, which can be determined based on the relative positions of the actual gear and the target gear. Specifically, gear shift status includes two states: upshifting and downshifting. If the actual gear is higher than the target gear, the gear shift status is determined to be downshifting. If the actual gear is lower than the target gear, the gear shift status is determined to be upshifting.

[0097] Furthermore, as mentioned above, shifting gears requires disengaging the clutch. To reduce impact on mechanical components and prevent vehicle jerking, the engine torque is typically reduced to a certain value before the clutch can disengage. Based on this, embodiments of this application can determine different torque reduction gradients according to the vehicle's current power demand and gear shift status, thereby further ensuring smoothness during gear shifting.

[0098] In one possible implementation, a target torque reduction gradient is determined based on the vehicle's driving power, discharge power, and gear shift state. This includes: determining a first torque reduction gradient as the target torque reduction gradient when the vehicle's driving power is less than or equal to the discharge power and the vehicle is in an upshift state; determining a second torque reduction gradient as the target torque reduction gradient when the vehicle's driving power is less than or equal to the discharge power and the vehicle is in a downshift state; wherein the first torque reduction gradient is less than the second torque reduction gradient; determining a third torque reduction gradient as the target torque reduction gradient when the vehicle's driving power is greater than the discharge power and the vehicle is in an upshift state; wherein the third torque reduction gradient is less than the first torque reduction gradient; and determining a fourth torque reduction gradient as the target torque reduction gradient when the vehicle's driving power is greater than the discharge power and the vehicle is in a downshift state; wherein the fourth torque reduction gradient is less than the second torque reduction gradient and greater than the third torque reduction gradient.

[0099] As in the above embodiments, based on the relationship between the vehicle's driving power and the discharge power, a low power demand range where the vehicle's driving power is less than or equal to the discharge power can be determined, denoted as the first range; and a high power demand range where the vehicle's driving power is greater than the discharge power can be denoted as the second range.

[0100] Figure 3 This is a schematic diagram of the control process for switching gears in direct drive mode provided in an embodiment of this application.

[0101] For example, such as Figure 3 As shown, the vertical axis represents the vehicle's current total driving power, in kW; the horizontal axis represents the vehicle's current speed, in kilometers per hour (kph).

[0102] exist Figure 3 In this process, based on the discharge power curve of the power battery, the total output power curve in direct drive mode, the vehicle drive power boundary after the clutch is disengaged during the shift process, the power shuffling curve during the torque reduction phase of direct drive shifting, and the power release curve during the torque increase phase of direct drive shifting, the following parameters can be used to determine the distribution of power output power: Figure 3 The three power regions are region 1, region 2 and region 3.

[0103] The discharge power curve of the power battery can typically be calculated in real time by the Battery Management System (BMS). Specifically, the BMS collects battery parameters such as voltage, current, temperature, and current remaining charge, and then combines this data with a pre-calibrated "discharge power - battery parameters" map (MAP) obtained through bench testing to determine the stable discharge power output of the power battery. Specifically, when the vehicle is in direct drive mode and the current speed is low, the vehicle is in the starting phase, primarily powered by the drive motor. At this time, the power battery needs to output significant power to initiate the vehicle's start-up. Therefore, at low speeds, the discharge power curve of the power battery in direct drive mode remains stable at a relatively high power level. As the vehicle speed increases, the engine gradually engages, reducing the assistance from the drive motor. At this point, the discharge power curve of the power battery exhibits a trend of "decreasing with increasing vehicle speed."

[0104] The total output power curve in direct drive mode can typically be calculated by the vehicle controller based on the power requirements and output capacity of the power source in direct drive mode. Specifically, the total output power in direct drive mode is usually the sum of the output power of the front drive motor, rear drive motor, and engine. When the vehicle is in direct drive mode and the current speed is low, the vehicle is in the starting phase. At this time, the engine has just started, and due to the slow engine response, it is mainly driven by the drive motor. The total output power curve remains stable at a relatively high power level. As the vehicle speed increases, the engine gradually intervenes, and the assistance of the drive motor decreases. At this time, the total output power curve also shows a trend of "decreasing with increasing vehicle speed".

[0105] The theoretical direct-drive vehicle power boundary refers to the upper limit of the vehicle's drive power that can be provided in direct-drive mode under ideal conditions. This power value is obtained based on the engine's optimal performance calibration at different speeds, reflecting the power level that the engine can achieve when fully utilizing its power output capability in direct-drive mode. In direct-drive mode, the corresponding theoretical direct-drive vehicle power boundary can usually be determined based on parameters such as engine speed, torque, and gear ratio on a pre-established engine power-speed characteristic curve.

[0106] The vehicle drive power boundary after the clutch is disengaged during gear shifting refers to the lowest stable vehicle drive power that direct drive mode can provide during gear shifting when the clutch is disengaged. Specifically, when the vehicle is shifting in direct drive mode, after the clutch is disengaged, the vehicle is currently driven only by the rear drive motor, and the vehicle drive power at this time is the output power of the rear drive motor.

[0107] The power shaving curve during the torque reduction phase of direct-drive shifting refers to the curve showing the change in overall vehicle drive power as the engine torque is gradually reduced during gear shifting in direct-drive mode to ensure smooth power transition and avoid sudden torque changes affecting vehicle stability and ride comfort. This power shaving curve during the torque reduction phase of direct-drive shifting can typically be plotted based on the current engine's torque reduction gradient.

[0108] The power release curve during the direct-drive shift torque increase phase refers to the change in overall vehicle drive power as the engine torque is increased in a certain gradient after the clutch is disengaged to meet the vehicle's power demands and ensure smooth operation. This power release curve during the direct-drive shift torque increase phase can typically be plotted based on the current engine's torque increase gradient.

[0109] For example, the power region below the discharge power curve of the power battery can be defined as Region 1; the region above the discharge power curve of the power battery, below the total output power curve in direct drive mode, and to the left of the power shaving curve in the direct drive shift torque reduction stage can be defined as Region 2; the region below the theoretical direct drive vehicle driving power boundary, above the vehicle driving power boundary after the clutch is opened during the shift process, to the right of the power shaving curve in the direct drive shift torque reduction stage, and to the left of the power release curve in the direct drive shift torque increase stage can be defined as Region 3.

[0110] Furthermore, such as Figure 3 As shown, when the vehicle's driving power is less than or equal to the power battery's discharge power, that is, when the value corresponding to the vehicle's driving power is below the power battery's discharge power curve or falls exactly on the power battery's discharge power curve, the vehicle's driving power is determined to be in region 1.

[0111] If the total vehicle drive power is greater than the discharge power of the power battery and less than or equal to the total output power of the vehicle in direct drive mode, that is, the value corresponding to the total vehicle drive power is above the discharge power curve of the power battery, and the value corresponding to the total vehicle drive power is below the total output power curve in direct drive mode or falls exactly on the total output power curve in direct drive mode, and the value corresponding to the total vehicle drive power is to the left of the power shaving curve in the torque reduction stage of direct drive, then the total vehicle drive power can be determined to be in region 2.

[0112] It is understandable that region 1 can be understood as the first interval mentioned above; region 2 can be understood as the second interval mentioned above.

[0113] The power range includes two sections: the first section and the second section. Gear shift states include downshifting and upshifting. Based on these power ranges and gear shift states, the following four scenarios can be identified:

[0114] Scenario 1: The power range is the first range, and the gear shift is upshifting.

[0115] Scenario 2: The power range is the first range, and the gear change state is downshifting.

[0116] Scenario 3: The power range is the second range, and the gear shift is upshifting.

[0117] Scenario 4: The power range is the second range, and the gear shift is downshifting.

[0118] The first torsion reduction gradient mentioned above is the torsion reduction gradient corresponding to scenario one, the second torsion reduction gradient is the torsion reduction gradient corresponding to scenario two, the third gradient is the torsion reduction gradient corresponding to scenario three, and the fourth gradient is the torsion reduction gradient corresponding to scenario four.

[0119] Understandably, both Scenario 1 and Scenario 3 involve upshifting, the difference being that Scenario 1 is an upshift below the first gear interval, while Scenario 3 is an upshift below the second gear interval. Scenario 2 and Scenario 4 involve downshifting, the difference being that Scenario 2 is a downshift below the first gear interval, while Scenario 4 is a downshift below the second gear interval.

[0120] As mentioned earlier, when the vehicle's driving power is in the first range (i.e., the low power demand range), it means that the vehicle's current power demand is low, and the power battery's discharge power is sufficient to meet the vehicle's current driving needs. At this time, there is no need to rely on the target motor's power generation to drive the vehicle. Even if the engine torque is rapidly reduced, it will not affect the vehicle's current power performance or significantly impact its smoothness. Therefore, the target torque reduction gradient corresponding to scenario one in the first range can be set to a relatively high first torque reduction gradient, and the target torque reduction gradient corresponding to scenario two in the first range can be set to a relatively high second torque reduction gradient.

[0121] When the vehicle's driving power is in the second range (i.e., the high power demand range), it means that the vehicle's current power demand is high, requiring simultaneous reliance on the discharge power of the power battery and the power generation power of the target motor to drive the vehicle. Since the target motor relies on the engine to generate electricity, rapidly reducing the engine torque at this time will cause the target motor's power generation power to drop drastically, resulting in a loss of vehicle power. This severely affects the vehicle's driving smoothness and may also pose a safety risk due to power interruption. Therefore, the target torque reduction gradient corresponding to scenario three in the second range can be set to a third torque reduction gradient lower than the first torque reduction gradient in scenario one, and the target torque reduction gradient corresponding to scenario four in the second range can be set to a fourth torque reduction gradient lower than the second torque reduction gradient in scenario two.

[0122] Upshifting indicates a greater demand for power from the vehicle. In this situation, a rapid torque reduction would result in a more noticeable power loss. Therefore, a relatively small torque reduction gradient is needed when upshifting. Downshifting indicates a lower demand for power, with more power available in the current gear. A rapid torque reduction wouldn't affect power output, so a relatively larger torque reduction gradient is needed when downshifting. Therefore, within the first power range, the first torque reduction gradient during upshifting is smaller than the second torque reduction gradient during downshifting. Within the second power range, the third torque reduction gradient during upshifting is smaller than the fourth torque reduction gradient during downshifting.

[0123] In some embodiments, the driving state can also be determined based on the accelerator pedal opening, which may include: coasting state, low throttle state, and high throttle state. For example, when the accelerator pedal opening is less than or equal to a first preset opening (e.g., 2%), the vehicle is determined to be in a coasting state. When the accelerator pedal opening is greater than the first preset opening (e.g., 2%) and less than or equal to a second preset opening (e.g., 15%), the vehicle is determined to be in a low throttle state. When the accelerator pedal opening is greater than the second preset opening (e.g., 15%), the vehicle is determined to be in a high throttle state.

[0124] In the first range, the vehicle is usually in a coasting state with the accelerator released. Therefore, the upshifting and downshifting states in the first range can be recorded as coasting upshifting and coasting downshifting states. In the second range, the vehicle is usually in a high throttle state. Therefore, the upshifting and downshifting states in the second range can be recorded as power upshifting and power downshifting states.

[0125] In some embodiments, the vehicle may also be in a low throttle state in the first interval, which is usually an upshift state. The upshift state in the first interval can also be recorded as a coasting or low throttle upshift state.

[0126] In the above method, by analyzing the relationship between the vehicle's driving power and the power battery's discharge power, the low-power demand range (where the vehicle's driving power is less than or equal to the power battery's discharge power) and the high-power demand range (where the vehicle's driving power is greater than the power battery's discharge power) can be determined. Based on these power ranges and the two gear shift states (upshifting and downshifting), four scenarios are identified. The torque reduction gradient in each scenario is defined as the target torque reduction gradient, achieving refined control of the target torque reduction gradient based on the current scenario's demand. Specifically, a larger torque reduction gradient corresponds to the low-power demand range, enabling rapid gear shifting and preventing the vehicle from entering the high-power demand range. A smaller torque reduction gradient corresponds to the high-power demand range, enabling smooth gear shifting and ensuring power continuity, thus avoiding power interruption caused by the engine torque dropping directly from high torque to zero. A smaller torque reduction gradient corresponds to upshifting, preventing excessive power loss that could affect driving comfort. A larger torque reduction gradient corresponds to downshifting, enabling rapid gear shifting.

[0127] In step 203, the target torque is the torque that the engine can output to ensure that the clutch can be safely disengaged. After determining that a gear shift is required, the target torque of the engine can be determined first, and then the target torque reduction gradient can be determined. The actual torque of the engine is then reduced to the target torque according to the target torque reduction gradient.

[0128] Understandably, the engine is connected to the transmission via a clutch. When the vehicle is driving in direct drive mode, the clutch is engaged, and the engine outputs a certain amount of torque. This torque is transmitted to the transmission input shaft through the engaged clutch, thus driving the vehicle. When it is necessary to disengage the clutch, to ensure safe disengagement, the engine torque must be reduced to a target torque that allows for safe clutch disengagement.

[0129] The torque of an engine can be divided into two parts: the firing torque and the air intake torque. Target torques need to be determined for both the firing and air intake torques. The following example illustrates this situation:

[0130] In one possible implementation, the target torque includes a target fire circuit torque and a target air circuit torque. The target torque is determined by the following methods: determining an initial air circuit torque request value based on the driver's required torque, the target front-to-rear axle torque distribution ratio, and the actual torque of the target motor; determining the target fire circuit torque based on the initial air circuit torque request value, the shift intervention torque, and the engine fire circuit speed control torque; and determining the target air circuit torque based on the initial air circuit torque request value, the engine air circuit reserved torque, the engine air circuit speed control reserved torque, and the target fire circuit torque.

[0131] Among them, the driver's required torque refers to the vehicle's required torque determined based on the driver's operation. Specifically, the vehicle can store the correspondence between various accelerator pedal openings and the corresponding driver's required torque. It can obtain the current accelerator pedal opening and determine the driver's required torque corresponding to that accelerator pedal opening based on the correspondence.

[0132] The target front-to-rear axle distribution ratio refers to the ratio between the torque required by the entire vehicle and the torque required by the rear axle, after the total torque requirement of the vehicle has been determined. For example, if the total torque requirement of the vehicle is 100 Nm, and 80 N is distributed to the front axle and 20 N to the rear axle, then the target front-to-rear axle distribution ratio is front axle:rear axle = 8:2.

[0133] In some embodiments, the vehicle's driving mode affects the aforementioned front-to-rear axle distribution ratio. For example, in Eco mode, to improve fuel economy, the vehicle may be biased towards single-axle drive (such as pure electric rear-wheel drive) to reduce energy consumption; in this case, the distribution ratio is front axle:rear axle = 0:10. In Sport mode, a distribution closer to 5:5 may be used to improve handling. In Four-Wheel Drive mode or Off-Road mode, a more balanced or rear-axle-biased distribution may be used to enhance off-road capability; in this case, the distribution ratio could be, for example, front axle:rear axle = 3:7. Therefore, the aforementioned target front-to-rear axle distribution ratio can be determined based on the vehicle's driving mode.

[0134] It is understood that the target front and rear axle allocation ratio can be a pre-set fixed value or be affected by other parameters. The above method for determining the target front and rear axle allocation ratio is only an example, and this application embodiment does not limit it.

[0135] The target motor is a motor that is rigidly connected to the gearbox, i.e. Figure 1 The front-drive motor 103 is located in the engine. The target motor is connected to the engine via a clutch. The power battery can provide electrical energy to the target motor to enable it to output torque. The actual torque of the target motor, i.e., the torque currently output by the target motor, can be obtained based on a torque sensor installed on the target motor.

[0136] The target torque of an engine can be divided into two types: target firing torque and target intake torque. Target firing torque refers to the portion of the target torque achieved by optimizing the combustion process of the air-fuel mixture in the cylinder through adjustments to the ignition system (mainly the ignition advance angle). Target intake torque refers to the portion of the target torque achieved by controlling the amount of air entering the engine cylinders through adjustments to the intake system (mainly throttle opening, variable valve timing, etc.).

[0137] The original air circuit torque request value refers to the air circuit torque value requested when the vehicle is not shifting gears in its current operating state. After obtaining the above information based on the driver's required torque, the target front-rear axle torque distribution ratio, and the actual torque of the target motor, the original air circuit torque request value can be calculated based on the driver's required torque, the target front-rear axle torque distribution ratio, and the actual torque of the target motor.

[0138] The process of calculating the original air circuit torque request value includes: determining the front axle distribution ratio based on the target front and rear axle torque distribution; multiplying the driver's required torque by the front axle distribution ratio to obtain the front axle distributed torque; and subtracting the actual torque of the target motor from the front axle distributed torque to obtain the original air circuit torque request value. The formula for calculating the original air circuit torque request value is shown in the following formula (3):

[0139] T3=T1*λ-T2 (3)

[0140] In the above formula (3), T3 is the original air circuit torque request value, T1 is the torque required by the driver, λ is the front axle torque distribution ratio, and T2 is the actual torque of the target motor.

[0141] For example, if the driver's required torque T1 is 100 NM and the target front-to-rear axle torque distribution ratio is: front axle: rear axle = 3:7, then the front axle torque distribution ratio λ is 0.3. The actual torque T2 of the target motor is 20 NM, then based on the above formula (3), the original air circuit torque request value T3 can be calculated as 100 * 0.3 - 20 = 10 NM.

[0142] Shift intervention torque refers to the torque used to instruct the engine to reduce torque. It is typically calculated by subtracting the target torque reduction gradient from the engine's current actual torque. As the actual engine torque indicated by the shift intervention torque decreases, the shift intervention torque gradually decreases until it reaches the target torque.

[0143] Engine speed control torque refers to the torque used to maintain the engine at a certain speed after the clutch is disengaged. The engine speed control torque can be determined based on the difference between the current engine speed and the required maintained speed. For example, if the clutch is disengaged and the engine needs to be maintained at 1500 rpm, and the current engine speed is below 1500 rpm, the engine speed control torque will increase slightly to bring the current engine speed to 1500 rpm. If the current engine speed is above 1500 rpm, the engine speed control torque will decrease slightly to reduce the engine speed to 1500 rpm.

[0144] After obtaining the original air circuit torque request value, shift intervention torque, and engine fire circuit speed control torque, the target fire circuit torque can be calculated based on the original air circuit torque request value, shift intervention torque, and engine fire circuit speed control torque.

[0145] The process of calculating the target fire circuit torque includes: determining the minimum value between the original gas circuit torque request value and the shift intervention torque as the initial torque; if the initial torque is greater than zero, determining the sum of the initial torque and the engine fire circuit speed control torque as the target fire circuit torque; if the initial torque is less than zero, determining the engine fire circuit speed control torque as the target fire circuit torque. The formula for calculating the target fire circuit torque is shown in the following formula (4):

[0146] T6 = max(min(T3,T4),0) + T5 (4)

[0147] In the above formula (4), T6 is the target fire circuit torque, T3 is the original air circuit torque request value, T4 is the shift intervention torque, and T5 is the engine fire circuit speed control torque.

[0148] For example, if the original air circuit torque request value T3 is 60 NM, the shift intervention torque T4 is 30 NM, and the engine fire circuit speed control torque is 0 NM, then the target fire circuit torque T6 = max(min(60, 30), 0) + 0 = 30 NM can be calculated based on the above formula (4).

[0149] Understandably, during gear shifting, the aforementioned shift intervention torque T4 will gradually decrease from the engine's current actual torque to 0 Nm, causing the target firing torque T6 to also decrease to 0 Nm. When disengaging the clutch for speed adjustment, the engine firing speed control torque will be used to adjust the speed. When the target speed is reached, the engine firing speed control torque will approach 0 Nm, resulting in the final target firing torque being reduced to 0 Nm.

[0150] Engine airflow reserve torque refers to the amount of torque adjustment required for the engine's airflow system. The vehicle stores a first mapping table between engine speed, the initial airflow torque request value, and the engine airflow reserve torque. After obtaining the initial airflow torque request value, the current engine speed can be acquired. Based on the engine speed and the initial airflow torque request value, the engine airflow reserve torque is obtained by looking up the first mapping table. The first mapping table is shown in Table 1 below:

[0151] Table 1

[0152] Y / X 0 800 1000 1200 1500 1800 2100 2400 3000 -10 0 0 30 30 30 30 30 30 30 10 0 0 10 10 10 10 10 10 10 20 0 0 0 0 0 0 0 0 0 70 0 0 -50 -50 -50 -50 -50 -50 -50 100 0 0 -80 -80 -80 -80 -80 -80 -80

[0153] In Table 1, Y represents the original airflow torque request value in Nm, and X represents the engine speed in rpm. As shown in Table 1, in the first mapping table, when the engine speed is less than a certain speed (e.g., 800 rpm in Table 1), regardless of whether the original airflow torque request value is positive or negative, the engine airflow reserved torque is 0, and no adjustment of the engine airflow torque is required. When the speed is greater than a certain speed (e.g., 800 rpm in Table 1), after adjusting the original airflow torque request value based on the engine airflow reserved torque, the adjusted airflow torque value usually remains at a preset fixed value.

[0154] Understandably, during engine torque reduction, when the difference between the combustion torque and the air intake torque is too large, engine fuel consumption is high, resulting in poor vehicle economy. The aforementioned preset fixed value represents the target value for reducing air intake torque, which ensures rapid engine recovery while minimizing fuel consumption.

[0155] As shown in Table 1, the adjusted engine airflow torque typically needs to be maintained at 20 Nm. Therefore, as shown in Table 1, when the original airflow torque request value is 20 Nm, the engine airflow reserve torque is 0; when the original airflow torque request value is less than 20 Nm, the engine airflow reserve torque is positive; and when the original airflow torque request value is greater than 20 Nm, the engine airflow reserve torque is negative. Overall, when the engine speed is greater than or equal to 1000 rpm, the larger the original airflow torque request value, the smaller the engine airflow reserve torque; conversely, the smaller the original airflow torque request value, the larger the engine airflow reserve torque, ultimately ensuring that the adjusted engine airflow torque is maintained at around 20 Nm. When the engine speed is less than 1000 rpm, the engine airflow reserve torque is zero, meaning no adjustment is made to the engine airflow torque.

[0156] The engine air circuit speed control reserve torque refers to the value used to ensure that the fluctuations in engine air circuit torque are consistent with the fluctuations in engine fire circuit torque. The engine air circuit speed control reserve torque can be determined based on the engine fire circuit speed control torque.

[0157] It is understandable that the engine air circuit torque will fluctuate while maintaining the engine speed, and the value causing the fluctuation is the aforementioned engine fire circuit speed control torque. In order to keep the fluctuation of the air circuit torque consistent with the fluctuation of the fire circuit torque, the engine air circuit speed control reserve torque can be determined based on the fire circuit speed control torque.

[0158] After obtaining the original gas path torque request value, the engine gas path reserved torque, the engine gas path speed control reserved torque, and the target ignition torque, the target gas path torque can be determined based on these values.

[0159] The process of calculating the target air path torque includes: adding the original air path torque request value to the engine air path reserved torque to obtain an intermediate value; adding the engine air path speed control reserved torque to the intermediate value to obtain the initial target air path torque; and determining the maximum value between the initial target air path torque and the target fire path torque as the target air path torque. The formula for calculating the target air path torque is shown in the following formula (5):

[0160] T9 = max(T3 + T7 + T8, T6) (5)

[0161] In the above formula (5), T9 is the target air circuit torque, T3 is the original air circuit torque request value, T7 is the engine air circuit reserved torque, T8 is the engine air circuit speed control reserved torque, and T6 is the target fire circuit torque.

[0162] For example, the original air circuit torque request value T3 is 10NM, the engine air circuit reserved torque T7 is 10NM, the engine air circuit speed control reserved torque T8 is 0NM, and the target fire circuit torque T6 is 10NM. The target air circuit torque T9 = max(10+10+0,10) = 20NM can be calculated based on the above formula (5).

[0163] In the above method, based on the original air circuit torque request value, shift intervention torque, and engine fire circuit speed control torque, the engine's target fire circuit torque can be dynamically calculated in real time. Simultaneously considering the engine fire circuit speed control torque, it ensures that the engine maintains a certain speed when the clutch is open, avoiding engine damage caused by excessively high or low engine speeds. Calculating the target air circuit torque based on the original air circuit torque, the engine air circuit reserved torque, the engine air circuit speed control reserved torque, and the target fire circuit torque ensures that a portion of the engine air circuit torque is reserved, guaranteeing that the target air circuit torque is not less than the target fire circuit torque and fluctuates with the target fire circuit torque, thus ensuring the accuracy of target torque control.

[0164] In one possible implementation, the target torque reduction gradient is determined based on the vehicle's driving power, discharge power, and gear shift status. This includes: obtaining the engine's original air circuit torque request value and the current accelerator pedal opening; determining the target correspondence based on the vehicle's driving power, discharge power, and gear shift status; and finding the target correspondence based on the original air circuit torque request value, accelerator pedal opening, vehicle driving power, and discharge power to obtain the target torque reduction gradient.

[0165] As in the above embodiment, the original air path torque request value can be obtained based on formula (3). The current travel of the accelerator pedal is detected by a position sensor located at the accelerator pedal, and the current opening degree of the accelerator pedal is calculated based on the current travel of the accelerator pedal.

[0166] As described in the above embodiment, multiple scenarios are obtained based on the vehicle's driving power, discharge power, and gear shift status. The vehicle stores the corresponding relationship for finding the target torque reduction gradient in each scenario. Based on the currently obtained vehicle driving power, discharge power, and gear shift status, the target scenario in which the vehicle is currently located can be determined, and the corresponding relationship in the target scenario can be identified as the target corresponding relationship.

[0167] As in the above embodiment, four scenarios are obtained. Let's assume the correspondence in scenario one is correspondence 1, the correspondence in scenario two is correspondence 2, the correspondence in scenario three is correspondence 3, and the correspondence in scenario four is correspondence 4. The fourth correspondence: If the target scenario the vehicle is currently in is scenario one, then correspondence 1 in scenario one is determined as the target correspondence.

[0168] After determining the target correspondence, the target correspondence can be found based on the original air circuit torque request value, accelerator pedal opening, vehicle drive power and discharge power to obtain the target torque reduction gradient.

[0169] In the above method, the power range can be determined by the relationship between the vehicle's driving power and the power battery's discharge power. Different scenarios can be determined based on the power demand range and gear change status. The vehicle's driving power, discharge power, and gear change status can determine the target correspondence with the current scenario, thereby determining the target torque reduction gradient. This achieves refined control of the target torque reduction gradient based on the demand under the current scenario, improving the reliability of torque reduction control.

[0170] In one possible implementation, the target correspondence includes a first correspondence and a second correspondence. The target torque reduction gradient is obtained by finding the target correspondence based on the original air circuit torque request value, accelerator pedal opening, vehicle drive power, and discharge power. This includes: calculating the power difference between the vehicle drive power and the discharge power; finding the first correspondence based on the original air circuit torque request value and the power difference to obtain the basic torque reduction gradient; finding the second correspondence based on the accelerator pedal opening and the power difference to obtain the first target correction coefficient; and determining the target torque reduction gradient based on the basic torque reduction gradient and the first target correction coefficient.

[0171] The target correspondence includes a first correspondence for determining the basic torsion reduction gradient and a second correspondence for determining the first target correction coefficient.

[0172] The first correspondence is specifically the correspondence between the two parameters, power difference and original air circuit torque request value, and the basic torque reduction gradient.

[0173] After determining the first and second correspondences, the vehicle's drive power can be subtracted from the discharge power to obtain the power difference. Then, based on the power difference and the original air circuit torque request value, the first correspondence is found to obtain the basic torque reduction gradient.

[0174] Understandably, when the vehicle's driving power is less than or equal to the discharge power, the power range is the first range, and therefore the power difference calculated within the first range is less than or equal to 0. When the vehicle's driving power is greater than the discharge power, the power range is the second range, and therefore the power difference calculated within the second range is greater than 0.

[0175] Table 2

[0176]

[0177] In Table 2, Y represents the original air path torque request value in NM, and Z represents the power difference in kW. Table 2 includes the first correspondence for Scenario 1 and the first correspondence for Scenario 3. As shown in Table 2, in the first correspondence for Scenario 1, when the power difference is less than or equal to 0, the torque reduction gradient is 1100 NM / s. In the first correspondence for Scenario 3, when the power difference is greater than zero, the torque reduction gradient is less than 1100 NM / s. Specifically, in the first correspondence for Scenario 3, when the original air path torque request value is less than or equal to a preset value (e.g., 20 NM in Table 2), the torque reduction gradient is affected by the magnitude of the power difference and is always 900 NM / s; when the original air path torque request value is greater than the preset value, with the original air path torque request value fixed, the torque reduction gradient decreases as the power difference increases; with the power difference fixed, the torque reduction gradient decreases as the original air path torque request value increases.

[0178] Understandably, Scenario 1 represents upshifting within the first gear range. In Scenario 1, the vehicle's driving power is less than or equal to the battery's discharge power. Therefore, in the first correspondence of Scenario 1, the power difference is less than or equal to 0. In Scenario 1, to prevent the engine torque from decreasing too slowly and causing the vehicle to enter the second gear range, a larger torque reduction gradient is needed for rapid gear shifting. Therefore, the torque reduction gradient in the first correspondence of Scenario 1 is a relatively large gradient of 1100 Nm / s. Scenario 3 represents upshifting within the second gear range. In Scenario 3, the vehicle's driving power is greater than the battery's discharge power. Therefore, in the first correspondence of Scenario 3, the power difference is greater than 0. To ensure smooth gear shifting, a smaller torque reduction gradient is needed to reduce torque fluctuations. Therefore, the torque reduction gradient in the first correspondence of Scenario 3 is usually smaller than the torque reduction gradient in the correspondence of Scenario 1.

[0179] When the vehicle's driving power exceeds the battery's discharge power, the battery is prone to over-discharge. The larger the power difference, the greater the risk of over-discharge. Therefore, a smaller torque reduction gradient is needed when the power difference is larger to reduce safety issues caused by engine torque changes. A larger initial airflow torque request indicates that the engine is operating under high load. In this case, a smaller torque reduction gradient can make the engine's operating state change more smoothly, reducing impact loads on internal engine components such as pistons, connecting rods, and crankshafts, helping to extend the service life of engine components and reducing the risk of engine damage due to drastic torque changes. Therefore, in the first correspondence under scenario three, when the initial airflow torque request is greater than the preset value, with a fixed initial airflow torque request, the torque reduction gradient decreases as the power difference increases; with a fixed power difference, the torque reduction gradient decreases as the initial airflow torque request increases.

[0180] When the original air circuit torque request value is less than or equal to the above preset value, it can be determined that the current output torque of the engine is small, and the fluctuation of the engine torque has little impact on the power battery. At this time, torque reduction can be performed based on a fixed and large torque reduction gradient.

[0181] Table 2 above is only one example. In some embodiments, the first correspondence under scenario 2 in Table 2 can also be such that, with the original air path torque request value fixed, the torque reduction gradient decreases as the power difference increases; with the power difference fixed, the torque reduction gradient decreases as the original air path torque request value increases.

[0182] Table 3

[0183]

[0184] In Table 3, Y represents the original air path torque request value in NM, and Z represents the power difference in kW. Table 3 includes the first correspondence for Scenario 2 and the first correspondence for Scenario 4. As shown in Table 3, in the first correspondence for Scenario 2, when the power difference is less than or equal to 0, the torque reduction gradient is 1200 NM / s. In the first correspondence for Scenario 4, when the power difference is greater than zero, the torque reduction gradient is less than or equal to 1200 NM / s. Specifically, in the first correspondence for Scenario 4, when the original air path torque request value is less than or equal to a preset value (e.g., 20 NM in Table 3), the torque reduction gradient is affected by the magnitude of the power difference and is always 1100 NM / s; when the original air path torque request value is greater than the preset value, with the original air path torque request value fixed, the torque reduction gradient decreases as the power difference increases; with the power difference fixed, the torque reduction gradient decreases as the original air path torque request value increases.

[0185] Scenario 2 is the downshifting scenario under the first interval, and Scenario 4 is the downshifting scenario under the second interval. The design idea of ​​Table 3 is similar to that of Table 2 above. The torque reduction gradient in the first correspondence under the second interval is less than the downshifting gradient in the first correspondence under the first interval.

[0186] The difference is that the torque reduction gradient found in Table 3, based on the same original air path torque request value and power difference, is usually greater than the torque reduction gradient found in Table 2.

[0187] It's understandable that in Table 2, scenarios one and three involve upshifting, while in Table 3, scenarios two and four involve downshifting. The torque reduction gradient in Table 2 represents the torque reduction gradient during upshifting, and the torque reduction gradient in Table 3 represents the torque reduction gradient during downshifting. Upshifting indicates a greater demand for vehicle power; in this case, rapid torque reduction would result in a more noticeable power loss. Therefore, a relatively smaller torque reduction gradient is needed during upshifting. Downshifting indicates a lower demand for vehicle power; the current gear provides more power, and rapid torque reduction does not affect power output. Therefore, a relatively larger torque reduction gradient is needed during downshifting.

[0188] When the target correspondence is a correspondence under a specific scenario, the first correspondence is specifically the first correspondence under a specific scenario in Table 2 above. In this case, Table 2 can be consulted based on the power difference and the original air path torque request value to determine the found torque reduction gradient as the basic torque reduction gradient.

[0189] For example, with a power difference of -10KW and an original air circuit torque request of 20NM, the basic torque reduction gradient can be found in Table 2 to be 1200NM / s.

[0190] The second correspondence is specifically the correspondence between the two parameters, power difference and accelerator pedal opening, and the first target correction coefficient.

[0191] The current accelerator pedal opening of the vehicle is obtained, and the total vehicle drive power is subtracted from the discharge power to obtain the power difference. Then, based on the power difference and the accelerator pedal opening, a second correspondence can be found to obtain the first target correction coefficient.

[0192] Table 4

[0193]

[0194] In Table 4, W represents the accelerator pedal opening (%), and Z represents the power difference (kW). Table 4 includes the second correspondence under Scenario 1 and the second correspondence under Scenario 2. As shown in Table 4, in the second correspondence under Scenario 1, when the accelerator pedal opening is less than or equal to the first opening (e.g., 50% in Table 4), the first target correction coefficient is 1, and no correction is needed for the base torque reduction gradient. When the accelerator pedal opening is greater than the first opening (e.g., 50% in Table 4), the first target correction coefficient is greater than 1, and the base torque reduction gradient needs to be amplified to obtain a larger torque reduction gradient. Specifically, when the accelerator pedal opening is greater than the first opening (e.g., 50% in Table 4), the first target correction coefficient increases with the increase of the accelerator pedal opening.

[0195] As shown in Table 4, in the second correspondence under Scenario 3, when the accelerator pedal opening is greater than or equal to the second opening (e.g., 80% in Table 4) and the power difference is less than or equal to the first difference (e.g., 20KW in Table 4), the first target correction coefficient is greater than 1. In this case, the basic torque reduction gradient needs to be amplified to obtain a larger torque reduction gradient. Specifically, the target coefficient decreases as the power difference increases and increases as the accelerator pedal opening increases. In the second correspondence under Scenario 3, when the accelerator pedal opening is less than the second opening (e.g., 80% in Table 4), or the power difference is greater than the first difference (e.g., 20KW in Table 4), the first target correction coefficient is 1. In this case, no correction to the basic torque reduction gradient is needed. The second opening is slightly larger than the first opening.

[0196] Understandably, Scenario 1 represents the first interval, where the vehicle's overall driving power is less than the battery's discharge power. When the accelerator pedal is fully open, the vehicle's power demand is high, potentially causing the overall driving power to exceed the battery's discharge power, leading the vehicle into the second interval. In this case, the torque reduction gradient can be increased to quickly reduce the engine's output torque and decrease the vehicle's overall driving power. Therefore, in the second correspondence of Scenario 1, when the accelerator pedal opening is greater than the first opening, the first target correction coefficient is greater than 1, used to amplify the basic torque reduction gradient. The larger the accelerator pedal opening, the greater the power demand, thus requiring a larger torque reduction gradient to reduce engine torque to ensure the overall driving power is less than the battery's discharge power. Therefore, in the second correspondence of Scenario 1, when the accelerator pedal opening is greater than the first opening, the number of target corrections increases with the increase of the accelerator pedal opening.

[0197] Scenario 3 is the scenario under the second interval. In this scenario, the vehicle's overall driving power is greater than the battery's discharge power. In Scenario 3, with a small power difference, the overall driving power slightly exceeds the battery's discharge power, and this scenario is close to Scenario 1 in the first interval. In the second pair of correspondences under Scenario 1, the first target correction coefficient is greater than 1 when the accelerator pedal opening is greater than the first opening. To avoid excessive changes in the torque reduction gradient after the vehicle enters the second interval from the first interval, in the second correspondence under Scenario 3, when the accelerator pedal opening is greater than the second opening, the first target correction coefficient is also greater than 1, used to achieve a smooth transition in the torque reduction gradient and prevent a sudden and significant decrease in the torque reduction gradient. Under the second interval, as the power difference increases, the vehicle needs to reduce torque based on a smaller torque reduction gradient. Therefore, in the second correspondence under Scenario 3, when the accelerator pedal opening is greater than the second opening, the first target correction coefficient decreases as the power difference increases. When the accelerator pedal opening is greater than the second opening, as the accelerator pedal opening increases, the trend of the first target correction coefficient needs to follow the trend of the first target correction coefficient in Scenario 1. In scenario one, when the accelerator pedal opening is greater than the first opening, the first target correction coefficient tends to increase as the accelerator pedal opening increases. Therefore, in scenario three, when the accelerator pedal opening is greater than the second opening and the power difference is less than or equal to the first difference, the first target correction coefficient tends to increase as the accelerator pedal opening increases.

[0198] Table 5

[0199]

[0200] In Table 5, W represents the accelerator pedal opening (%), and Z represents the power difference (kW). Table 5 includes the second correspondence under Scenario 2 and Scenario 4. As shown in Table 5, the second correspondence under Scenario 2 can be the same as the second correspondence under Scenario 1. The second correspondence under Scenario 4 can be the same as the second correspondence under Scenario 3. Under the same accelerator pedal opening and power difference, the first target correction coefficient obtained by looking up Table 5 is the same as the first target correction coefficient obtained by looking up Table 4.

[0201] Alternatively, in some embodiments, under the same accelerator pedal opening and power difference, the first target correction coefficient obtained by looking up Table 5 is greater than the first target correction coefficient obtained by looking up Table 4. The trend of the first target correction coefficient in Table 5 is the same as the trend of the first target correction coefficient in Table 4.

[0202] It is understood that the first and second correspondences shown in Tables 2 to 5 above are merely examples, and the embodiments of this application do not limit them.

[0203] When the target correspondence is the correspondence under scenario one, the second correspondence is specifically the second correspondence under scenario one in Table 4 above. At this time, the first target correction coefficient can be obtained by looking up Table 4 based on the power difference and accelerator pedal opening value.

[0204] For example, with a power difference of -10KW and an accelerator pedal opening of 80%, the first target correction factor can be found to be 1.5 by referring to Table 4.

[0205] After obtaining the basic torsion reduction gradient and the first target correction coefficient, the basic torsion reduction gradient can be multiplied by the target coefficient to obtain the target torsion reduction gradient. As in the above embodiment, the basic torsion reduction gradient is found to be 1100 NM / s by looking up Table 1, and the first target correction coefficient is found to be 1.5 by looking up Table 4. Therefore, the target torsion reduction gradient = 1100 * 1.5 = 1650 NM / s.

[0206] In the above method, when determining the basic torque reduction gradient, the power difference and the original air circuit torque request value are considered. The power difference reflects the relationship between the vehicle's driving power and the battery's discharge power, thus indicating potential over-discharge of the battery. A larger power difference indicates a greater risk of battery over-discharge, ensuring that the determined basic torque reduction gradient avoids this. The original air circuit torque request value characterizes the engine's high-load operating state, ensuring the determined basic torque reduction gradient avoids high engine load. The accelerator pedal opening represents power demand. Based on the accelerator pedal opening and the power difference, a first target correction coefficient is determined to adjust the basic torque reduction gradient, ensuring the target torque reduction gradient takes into account the vehicle's current power demand, further improving the accuracy of torque reduction control.

[0207] It is understandable that controlling the reduction of engine torque involves two types of control: controlling the torque in the spark circuit and controlling the torque in the air circuit. The spark circuit and the air circuit are two different torque adjustment paths.

[0208] Among them, fire circuit torque refers to the torque adjustment achieved by controlling ignition, such as adjusting the ignition advance angle. Fire circuit torque is usually adjusted quickly, so it can also be called "fast circuit torque".

[0209] Airway torque refers to torque adjustment achieved by controlling the intake air volume, such as by adjusting the throttle opening. Airway torque is usually slow to adjust, so it can also be called "slow-path torque".

[0210] Currently, when shifting gears in direct drive mode, the firing torque is typically reduced during the process of controlling engine torque reduction. However, to ensure that the engine output torque can be quickly restored upon entering direct drive mode, the air intake torque is usually not reduced. However, the inventors of this application have discovered that if the air intake torque is not reduced during gear shifting in direct drive mode, it can affect engine operation. For example, an excessively large difference between the air intake torque and the firing torque can lead to severe air-fire separation, incomplete combustion, and consequently, increased fuel consumption and excessive emissions. Therefore, in this embodiment, while controlling the reduction of firing torque, the air intake torque is also reduced, and the absolute value of the torque difference between the firing torque and the air intake torque is maintained within a certain range during the torque reduction process, thereby preventing air-fire separation caused by an excessively large difference between the air intake torque and the firing torque.

[0211] For example, the above-mentioned preset difference can be set according to actual needs. For instance, it can be set to 20 NM, which means that during the torque reduction process, the torque difference between the fire circuit torque and the air circuit torque must always be less than or equal to 20 NM to ensure the vehicle's economy.

[0212] In controlling engine torque reduction, the torque in the combustion circuit can usually be reduced by controlling the ignition timing release (e.g., retarding the ignition timing to an angle where combustion is "ineffective"). However, if the controller randomly or blindly controls the ignition timing release, it may lead to problems such as uncontrolled combustion torque and severely excessive emissions. Therefore, before controlling the ignition timing release, the adjustment range of the ignition timing should be determined first, and then the ignition timing release should be controlled based on the adjustment range.

[0213] In some embodiments, a mapping table between the two parameters of intake air volume and engine speed and the adjustment range of ignition angle can be established in advance. In practical applications, the target adjustment range of the corresponding ignition angle can be determined based on the current intake air volume and current engine speed of the engine in the preset mapping table.

[0214] For example, the process of establishing the above mapping table can be as follows: Under the same intake volume and the same speed, gradually increase the ignition advance angle (adjust in the "advanced" direction) from zero, while measuring the current spark torque. As the ignition advance angle increases, the combustion time becomes more sufficient, and the spark torque gradually increases. If the spark torque rises to a certain torque value (peak value), even if the ignition advance angle continues to increase, the spark torque will no longer continue to rise, indicating that the maximum torque value corresponding to the spark torque has been reached. The ignition advance angle at this time is the optimal ignition angle under the current intake volume and current speed, and this optimal ignition angle is denoted as θ0.

[0215] Furthermore, keeping the intake air volume and engine speed constant, starting from the optimal ignition angle determined above, gradually delay the ignition advance angle (adjusting towards "lag") while simultaneously measuring the current spark torque. As the ignition advance angle is delayed, the combustion time shortens and the combustion efficiency decreases, causing the spark torque to gradually decrease. If the spark torque drops to a certain limit when delayed to a certain angle (at which point the air-fuel mixture inside the engine can still continue to burn), further delaying the ignition advance angle at this point will cause the air-fuel mixture inside the engine to fail to burn, and the spark torque will drop directly to zero. This indicates that the minimum torque value corresponding to the spark torque has been reached. The ignition advance angle at this point is the latest ignition angle under the current intake air volume and engine speed, and this latest ignition angle is denoted as θ1.

[0216] As the ignition advance angle is gradually delayed from the optimal ignition angle, the delay may lead to increased fuel consumption and emissions exceeding standards. Considering the requirements of engine "economy" and "environmental protection", emissions and fuel consumption can be measured simultaneously during the delay to ensure they do not exceed the target emission limit (i.e., the emission limit stipulated by regulations) and the target fuel consumption limit (i.e., the fuel consumption limit corresponding to the current driving mode). If the emissions or fuel consumption just reach the target emission limit when the ignition advance angle is delayed to a certain angle, further delaying the ignition advance angle may cause emissions or fuel consumption to exceed standards. In this case, the ignition advance angle at this point can be determined as the latest ignition angle at which fuel consumption or emissions just meet the standards under the current intake air volume and current speed, and this latest ignition angle is denoted as θ2.

[0217] While determining the limit adjustment range of the ignition angle, considering the requirements of the engine's "economy" and "environmental protection", the above [θ0, θ2] can be used as the adjustment range of the ignition angle under the current intake air volume and the current engine speed of the engine.

[0218] By analogy, the above operation can be repeated under different intake volumes and different speeds to obtain the adjustment range of the ignition angle under different intake volumes and different speeds, i.e., the above mapping table.

[0219] During the process of controlling the reduction of engine torque, the current intake air volume and current speed of the engine can be obtained, and the target adjustment range of the ignition angle can be determined based on the current intake air volume and current speed.

[0220] Since the engine's intake air volume and speed remain constant, the engine's air circuit torque is usually fixed, while the ignition angle adjustment usually determines the magnitude of the spark circuit torque. Therefore, the size of the ignition angle will affect the difference between the air circuit torque and the spark circuit torque.

[0221] For example, if the ignition angle is the optimal ignition angle, the energy utilization rate is the highest, and the difference between the gas path torque and the fire path torque is zero. If the ignition angle is too late or too early, it may lead to a decrease in combustion efficiency, making the fire path torque much greater than the gas path torque, thus making the difference between the fire path torque and the gas path torque too large.

[0222] Based on this, the preset difference can be determined according to the target adjustment range of the ignition angle determined above, and by controlling the absolute value of the torque difference between the fire circuit torque and the air circuit torque to be less than or equal to the preset difference, the engine ignition angle can be ensured to be within the target adjustment range.

[0223] For example, a mapping relationship between the target adjustment range of the ignition angle and the preset difference can be established. After determining the target adjustment range of the ignition angle at the current intake volume and current speed, the preset difference corresponding to the target adjustment range can be determined based on the mapping relationship.

[0224] For example, if the target adjustment range is [θ0, θ2], based on this mapping relationship, the preset difference value corresponding to the target adjustment range can be determined to be 20 NM.

[0225] Furthermore, as mentioned above, a target torque reduction gradient can be determined based on the aforementioned basic torque reduction gradient and the first target correction coefficient. This target torque reduction gradient can include a target fire path torque reduction gradient and a target gas path torque reduction gradient. To ensure that the torque difference between the fire path torque and the gas path torque remains at a preset value during the torque reduction process, the target fire path torque reduction gradient can be determined first. Then, by correcting the target fire path torque reduction gradient, the target gas path torque reduction gradient can be obtained. Based on the determined target fire path torque reduction gradient and target gas path torque reduction gradient, the fire path torque and the gas path torque are simultaneously reduced so that the absolute value of the torque difference between the reduced fire path torque and the reduced gas path torque is less than or equal to the preset difference.

[0226] In one possible implementation, the target torque reduction gradient includes a target fire path torque reduction gradient and a target gas path torque reduction gradient. Determining the target torque reduction gradient based on the base torque reduction gradient and the first target correction coefficient includes: multiplying the base torque reduction gradient and the first target correction coefficient to obtain the target fire path torque reduction gradient; and correcting the target fire path torque reduction gradient based on a second target correction coefficient to obtain the target gas path torque reduction gradient; wherein the target fire path torque reduction gradient is greater than the target gas path torque reduction gradient; and the second target correction coefficient is used to control the torque difference between the reduced fire path torque and the reduced gas path torque to be less than or equal to a preset difference.

[0227] It is understandable that the target fire path torque reduction gradient can be obtained by multiplying the basic torque reduction gradient obtained from the table with the first target correction coefficient. In order to ensure that the absolute value of the torque difference between the fire path torque and the gas path torque is always less than or equal to the preset difference during the torque reduction process, the target fire path torque reduction gradient can be corrected to obtain the target gas path torque reduction gradient.

[0228] For example, the correction of the target fire path torque reduction gradient based on the second target correction coefficient can be specifically achieved by multiplying the target fire path torque reduction gradient by the second target correction coefficient to obtain the target gas path torque reduction gradient.

[0229] The second target correction coefficient is typically greater than zero. When the second target correction coefficient is less than 1, it means that the target gas path torque reduction gradient is reduced to a smaller value, resulting in a target gas path torque reduction gradient that is less than the target fire path torque reduction gradient. When the second target correction coefficient is greater than 1, it means that the target fire path torque reduction gradient is reduced to a larger value, resulting in a target gas path torque reduction gradient that is greater than the target fire path torque reduction gradient. When the second target correction coefficient is equal to 1, it means that the target fire path torque reduction gradient is not corrected, resulting in a target gas path torque reduction gradient that is equal to the target fire path torque reduction gradient.

[0230] For example, the aforementioned second target correction coefficient can be set according to the actual situation, specifically based on the preset difference. Assuming the preset difference is set to 20 NM, and the target fire path torque reduction gradient determined based on Tables 2 and 3 is 900 NM / s, after controlling the reduction of fire path torque based on this target fire path torque reduction gradient, the fire path torque decreases from 140 NM to 90 NM, while the current gas path torque is 120 NM. To ensure that the torque difference between the reduced fire path torque and the reduced gas path torque is less than or equal to 20 NM, the aforementioned second target correction coefficient is determined to be 0.2, i.e., the target gas path torque is 180 NM / s.

[0231] Understandably, during the process of controlling engine torque reduction, the engine's spark torque typically decreases to zero, while the engine's air intake torque usually has a reserve, meaning it won't decrease to zero. Therefore, the rate of decrease in the engine's spark torque must generally be greater than the rate of decrease in the engine's air intake torque to ensure that when the engine's air intake torque decreases to the reserve torque value, the engine's spark torque exactly decreases to zero. This ensures that the torque difference between the spark torque and the air intake torque during torque reduction is always less than or equal to a preset difference. Therefore, the aforementioned target spark torque reduction gradient is usually greater than the aforementioned target air intake torque reduction gradient.

[0232] In some embodiments, the target gas path torque reduction gradient can also be determined based on the first and second correspondences. That is, the basic torque reduction gradient of the gas path torque is first determined based on the first correspondence of the gas path torque, and then the first target correction coefficient is determined based on the second correspondence of the gas path torque. The product of the first target correction coefficient and the basic torque reduction gradient is determined as the target gas path torque reduction gradient.

[0233] The difference lies in the fact that, under the same parameters, the basic torque reduction gradient in the first correspondence of the gas path torque is generally smaller than the basic torque reduction gradient in the first correspondence of the fire path torque, and the first target correction coefficient in the second correspondence of the gas path torque is generally smaller than the first target correction coefficient in the second correspondence of the fire path torque, so that the target fire path torque reduction gradient is always greater than the target gas path torque reduction gradient.

[0234] It is understandable that the target fire path torque reduction gradient may change. In this case, the second target correction coefficient will change with the change of the target fire path torque reduction gradient, which will in turn cause the target gas path torque reduction gradient to change.

[0235] Furthermore, after determining the target fire path torque reduction gradient and the target gas path torque reduction gradient, the fire path torque and gas path torque can be reduced simultaneously according to the determined target fire path torque reduction gradient and the target gas path torque reduction gradient.

[0236] In the above method, determining the target fire circuit torque reduction gradient and the target air circuit torque reduction gradient can achieve torque reduction control for both the engine's fire circuit torque and air circuit torque. The second target correction coefficient can ensure that the torque difference between the reduced fire circuit torque and the reduced air circuit torque is less than or equal to the preset difference, ensuring that the separation of the air circuit and the fire circuit during the torque reduction process will not lead to high fuel consumption, thus improving the vehicle's economy during gear shifting.

[0237] In one possible implementation, the target torque reduction gradient includes a target fire path torque reduction gradient and a target air path torque reduction gradient, and the target torque includes a target fire path torque and a target air path torque, wherein the target air path torque is greater than the target fire path torque. Based on the target torque reduction gradient, the actual torque of the engine is controlled to be reduced to the target torque, including: controlling the engine's fire path torque to be reduced to the target fire path torque according to the target fire path torque reduction gradient; and during the process of controlling the engine's fire path torque to be reduced according to the target fire path torque reduction gradient, controlling the engine's air path torque to be reduced to the target air path torque according to the target air path torque reduction gradient, so as to ensure that the absolute value of the torque difference between the reduced fire path torque and the reduced air path torque is less than or equal to a preset difference, and ensuring that the engine's ignition angle is within the target adjustment range.

[0238] It is understandable that, since the aforementioned target air path torque reduction gradient is obtained by correcting the target fire path torque reduction gradient, and the correction amount of the target air path torque reduction gradient is determined based on the preset difference between the desired fire path torque and the air path torque, by controlling the fire path torque to decrease according to the target fire path torque reduction gradient, and simultaneously controlling the air path torque to decrease according to the target air path torque reduction gradient, it is possible to achieve a double reduction in both air path torque and fire path torque. Furthermore, it is possible to ensure that the absolute value of the torque difference between the reduced fire path torque and the reduced air path torque is always less than or equal to the preset difference, thereby ensuring that the engine's ignition angle is always within the target adjustment range.

[0239] Furthermore, if the ignition timing adjustment still fails to reduce the ignition torque to the target ignition torque, it indicates that the target ignition torque requested by the VCU has exceeded the torque range that the ignition timing adjustment can cover. In this case, in order to continue to control the reduction of the engine's ignition torque, the engine can be deactivated to reduce the engine's ignition torque to the target ignition torque.

[0240] In one possible implementation, the method further includes: if the controlled engine's fire circuit torque, after being reduced according to the target fire circuit torque reduction gradient, does not reach the target fire circuit torque, then determining the target number of cylinders to be cut off in the engine based on the target fire circuit torque and the target torque range of a single cylinder; wherein the target torque range of a single cylinder is determined based on the target adjustment range of the ignition angle; and performing cylinder cut-off processing on the cylinders corresponding to the target number of cylinders to reduce the fire circuit torque to the target fire circuit torque value.

[0241] Understandably, the vehicle controller can monitor in real time the relationship between the actual firing torque achieved after adjusting the engine's ignition timing and the target firing torque. If the actual firing torque consistently exceeds the target firing torque, it can be determined that adjusting the ignition timing is insufficient to reduce the firing torque to the target level. The vehicle controller can then use a cylinder deactivation request to control the engine's firing torque to decrease to the target firing torque.

[0242] Furthermore, based on the target adjustment range of the ignition angle determined above, the target torque range corresponding to a single cylinder can be determined. This target torque range represents the range of torque that can be output through ignition angle adjustment. For example, if the target adjustment range of the ignition angle is [θ0, θ2], it is determined that the output torque of a single cylinder can be [5NM, 20NM] through ignition angle adjustment. Then, based on the target firing torque and the target torque range corresponding to a single cylinder determined above, the number of working cylinders that need to be retained is determined. Subtracting the number of working cylinders that need to be retained from the total number of cylinders in the engine yields the target number of cylinders that need to be deactivated.

[0243] For example, assuming the target firing torque is 5 NM, the target torque range for a single cylinder is determined to be [5 NM, 20 NM], and the engine is a 4-cylinder engine, it means that adjusting the ignition angle alone cannot reduce the firing torque to the target firing torque, and cylinder deactivation is required. When only one cylinder is working, the minimum torque value that the cylinder can reach is exactly equal to the target firing torque. Therefore, it can be determined that the number of working cylinders to be retained is 1, and the target number of cylinders to be deactivated is 3.

[0244] Furthermore, after determining the target number of cylinders to be deactivated, the cylinders corresponding to that target number can be controlled to undergo cylinder deactivation. Specifically, cylinder deactivation can involve: ceasing fuel injection into the cylinders requiring deactivation, stopping the spark plugs in the cylinders requiring deactivation from generating an electric spark, and closing the intake and exhaust valves in the cylinders requiring deactivation. Through these cylinder deactivation processes, the cylinders can be stopped from operating, thereby reducing the engine's firing torque to the target firing torque value.

[0245] In step 204, controlling the actual torque of the engine to equal the target torque includes: controlling the engine's air path torque to equal the target air path torque and controlling the engine's spark path torque to equal the target spark path torque. Specifically, as in the above embodiment, the target air path torque is 20 NM and the target spark path torque is 0 NM. Controlling the actual torque of the engine to equal the target torque includes controlling the engine's air path torque to equal 20 NM and controlling the engine's spark path torque to equal 0 NM.

[0246] When the air circuit torque drops to 20 Nm and the combustion circuit torque drops to 0 Nm, it indicates that the engine's actual torque has decreased to 0 Nm. When the torque of the front drive motor also drops to near zero (for example, the absolute value of the front drive motor's torque is less than 5 Nm), the vehicle's clutch can be disengaged, disconnecting the engine and transmission. By controlling the transmission's synchronizer, the gear shift can be achieved by shifting from the current gear to neutral and then from neutral to the target gear.

[0247] In one possible implementation, the control clutch is in an open state so that after the vehicle performs a gear shift operation while the clutch is in an open state, the method further includes: when the vehicle completes the gear shift, controlling the speed difference between the two ends of the clutch to decrease; when the speed difference between the two ends of the clutch is less than or equal to a preset speed difference, controlling the clutch to be in a closed state; when the clutch is in a closed state, determining a target torque increase gradient; and controlling the actual torque of the engine to increase based on the target torque increase gradient so that the engine drives the vehicle.

[0248] When the vehicle's actual gear and target gear are equal, it can be determined that the gear shift has been completed. At this point, the target speed of the front drive motor can be determined based on the engine's current speed. By controlling the actual speed of the front drive motor, the target speed can be achieved, reducing the speed difference between the two ends of the clutch.

[0249] Speed ​​sensors can be installed at both ends of the clutch to detect the speed at each end of the clutch. During the process of controlling the actual speed of the front drive motor to reach the target speed, the two speeds collected by the speed sensors at both ends of the clutch can be acquired, and the difference between the two speeds can be calculated to obtain the aforementioned speed difference.

[0250] The preset speed difference is the maximum speed difference that can exist between the two ends of the clutch when the clutch is safely and smoothly closed. When the speed difference between the two ends of the clutch is less than the preset speed difference, it can be determined that the clutch can be safely and smoothly closed at this time, and the clutch is controlled to be in the closed state.

[0251] After confirming that the clutch is engaged, the engine can continue to output torque to drive the vehicle. Since the engine torque was reduced to the target torque before shifting gears, it is now necessary to control the engine torque to increase so that the engine can output torque to drive the vehicle.

[0252] Understandably, after shifting gears in direct drive mode, the vehicle's drive mode remains direct drive. At this point, the engine still needs to output power to propel the vehicle. Therefore, after engaging the clutch, it's necessary to control the engine's torque output. The engine's torque is transmitted to the transmission via the engaged clutch, and then the transmission's currently engaged gear further transmits power to the front wheels, ultimately driving the vehicle.

[0253] To ensure vehicle stability, a torque gradient can be determined, and the engine torque can be controlled to gradually increase according to the torque gradient to avoid excessive fluctuations in engine torque that could cause vehicle instability.

[0254] In some embodiments, the required torque for the entire vehicle can be determined based on the current throttle opening, and the target value that the engine output torque needs to reach can be determined based on the required torque for the entire vehicle. It is understood that the throttle opening changes in real time while the driver is driving the vehicle, so the target value that the engine output torque needs to reach also changes with the change in throttle opening.

[0255] In one possible implementation, determining the target torque increase gradient includes: acquiring the current engine speed, the current engine torque, the clutch pressure, the accelerator pedal opening, and the current vehicle speed; determining a basic torque increase gradient based on the current engine speed and the current engine torque; determining a first correction coefficient based on the current engine torque and the clutch pressure; determining a second correction coefficient based on the accelerator pedal opening and the current vehicle speed; and determining the target torque increase gradient by combining the basic torque increase gradient, the first correction coefficient, and the second correction coefficient.

[0256] The current engine speed mentioned above is the actual speed at which the engine is currently rotating. A speed sensor can be installed in the engine. After determining that the clutch is in the closed state, the engine speed currently collected by the speed sensor installed in the engine can be obtained to obtain the current engine speed mentioned above.

[0257] The current torque of the engine is the actual torque currently output by the engine. As in the above embodiment, a torque sensor can be installed in the engine. After determining that the clutch is in the closed state, the torque of the engine currently collected by the torque sensor installed in the engine can be obtained to obtain the current torque of the engine.

[0258] Clutch pressure specifically refers to the pressure applied to both sides of the clutch when it is engaged, measured in Newton-hours (N). In the case of a hydraulic clutch, the clutch pressure can be determined based on the clutch oil pressure. The pressure-to-torque ratio, measured in Nm, can then be determined based on the clutch pressure.

[0259] As in the above embodiments, the accelerator pedal travel can be detected, and the accelerator pedal opening can be determined based on the accelerator pedal travel.

[0260] The current vehicle speed refers to the speed at which the vehicle is currently traveling. As in the above embodiment, the vehicle's wheels are equipped with rotational speed sensors, which can acquire the wheel speed currently collected by the sensors. Based on the wheel speed and wheel radius, the vehicle's current speed is calculated. Alternatively, the vehicle's current speed can also be measured using an inertial measurement unit or a global positioning system. This application does not limit the method of acquiring the current vehicle speed.

[0261] The vehicle stores a third correspondence between the engine's current speed and torque and the torque-to-lift gradient. After obtaining these parameters, the basic torque-to-lift gradient can be obtained by looking up the third correspondence based on the engine's current speed and torque. The specific third correspondence is shown in Table 6 below:

[0262] Table 6

[0263] A / B 1000 1500 2000 3000 4000 5000 6000 -10 1200 1200 1200 1200 1200 1200 1200 20 300 300 300 500 500 500 500 40 300 300 300 500 500 500 500 50 300 300 300 500 500 500 500 80 300 300 300 500 500 500 500 100 300 300 300 500 500 500 500

[0264] In Table 6, A represents the current engine torque in Nm, and B represents the current engine speed in rpm. In the third correspondence shown in Table 6, when the current engine torque is negative, the torque increase gradient is relatively large, consistently around 1200 Nm / s. When the current engine torque is positive, the torque increase gradient is relatively small, ranging from 300 Nm / s to 500 Nm / s, as shown in Table 6. Furthermore, in the third correspondence, when the current engine torque is positive, and the current engine torque is constant, the torque increase gradient increases with the increase of the current engine speed.

[0265] Understandably, when the engine's current torque is negative, it indicates that the engine is currently decelerating. The negative torque can easily cause the engine speed to drop, potentially leading to engine stall. After the clutch engages, the engine needs to output torque to drive the vehicle. To prevent engine stall and to ensure rapid torque output, a large torque ramp-up gradient can be used to control the engine's torque increase. Therefore, in the third correspondence, when the engine torque is negative, the torque ramp-up gradient is large, consistently around 1200 Nm / s.

[0266] When the engine's current torque is positive, it indicates that the engine is currently outputting torque normally, and there is no risk of engine stalling. At this time, it is necessary to control the engine's torque increase based on a small torque increase gradient to ensure vehicle smoothness. Therefore, in the third correspondence, when the engine torque is positive, the torque increase gradient is relatively small, falling within the range of 300 Nm / s to 500 Nm / s, as shown in Table 6.

[0267] When the engine's current speed is at the mid-to-high range, intake inertia and optimized valve timing result in a "non-linear improvement in intake efficiency." This, combined with increased combustion efficiency and a decrease in the proportion of mechanical losses, significantly accelerates the increase in intake volume and effective torque per unit speed increase. At this point, the engine's torque increase can be controlled based on a larger torque gradient. Therefore, in the third correspondence, when the engine torque is positive, for a given engine torque, the torque increase gradient increases with increasing engine speed.

[0268] For example, the current engine speed is 2000 rpm and the current engine torque is 20 NM. Based on 2000 rpm and 20 NM, it can be found in Table 6 above that the basic torque gradient is 300 NM / s.

[0269] The vehicle stores a fourth correspondence between two parameters: the current engine torque and the torque corresponding to the clutch pressure, and the first correction coefficient. After obtaining these parameters, the first correction coefficient can be obtained by looking up the fourth correspondence based on the current engine torque and the torque corresponding to the clutch pressure. The specific fourth correspondence is shown in Table 7 below:

[0270] Table 7

[0271] C / A 0 10 30 60 80 100 140 0 0.5 0.45 0.4 0.35 0.3 0.25 0.2 10 1 0.5 0.45 0.4 0.35 0.3 0.25 30 1 1 0.5 0.45 0.4 0.35 0.3 60 1 1 1 0.5 0.45 0.4 0.35 80 1 1 1 1 0.5 0.45 0.4 100 1 1 1 1 1 0.5 0.45 140 1 1 1 1 1 1 0.5

[0272] In Table 7, A represents the current engine torque in Nm, and C represents the torque corresponding to the clutch pressure in Nm. In the fourth correspondence shown in Table 7, when the current engine torque is less than the torque corresponding to the clutch pressure, the first correction coefficient is 1, and no correction is made to the basic torque increase gradient. When the current engine torque is greater than or equal to the torque corresponding to the clutch pressure, the first correction coefficient is less than 1, and the torque increase gradient is reduced based on the first correction coefficient. That is, the engine torque increase rate slows down. When the current engine torque is greater than or equal to the torque corresponding to the clutch pressure, with the clutch pressure torque fixed, the first correction coefficient decreases as the current engine torque increases. The basic torque increase gradient will be reduced to a smaller gradient.

[0273] Understandably, the engine's current torque is transmitted to the transmission via the clutch. When the torque corresponding to the clutch pressure is greater than the engine's current torque, the entire current torque can be transmitted to the transmission. Furthermore, the engine torque increased by the torque gradient can usually be safely transmitted to the transmission via the clutch as well, in which case the basic torque gradient does not need to be corrected. Therefore, in the fourth correspondence, when the engine's current torque is less than the torque corresponding to the clutch pressure, the first correction factor is 1.

[0274] When the engine's current torque is greater than or equal to the torque corresponding to the clutch pressure, after controlling the engine torque increase based on the basic torque increase gradient, a significant portion of the engine torque will exceed the torque corresponding to the clutch pressure. In this case, there is a risk of clutch slippage. To avoid clutch slippage caused by a sudden increase in engine output torque, the torque increase gradient needs to be smoother. Therefore, in the fourth correspondence, when the engine's current torque is greater than or equal to the torque corresponding to the clutch pressure, the first correction coefficient is less than 1, thus reducing the basic torque increase gradient.

[0275] The greater the torque corresponding to the clutch pressure when the engine's current torque is greater than or equal to the torque, the higher the risk of clutch slippage. In this case, the force applied to smooth the torque increase gradient should be greater to make the engine torque rise more slowly. Therefore, in the fourth correspondence, when the engine's current torque is greater than or equal to the torque corresponding to the clutch pressure, and the torque corresponding to the clutch pressure is fixed, the first correction coefficient decreases as the engine's current torque increases. The basic torque increase gradient will be reduced to a smaller gradient.

[0276] For example, if the current torque of the engine is 20 NM and the torque corresponding to the clutch pressure is 20 NM, then based on the current torque of the engine of 20 NM and the torque corresponding to the clutch pressure of 20 NM, we can find in Table 7 above that the first correction factor is 0.5.

[0277] The vehicle stores a fifth correspondence between two parameters: accelerator pedal opening and current vehicle speed, and the second correction coefficient. After obtaining these parameters, the fifth correspondence can be looked up based on the accelerator pedal opening and current vehicle speed to obtain the second correction coefficient. The specific fifth correspondence is shown in Table 8 below:

[0278] Table 8

[0279] D / W 0 20 40 60 80 100 0 0.5 0.6 0.8 1 1 1 20 0.5 0.6 0.8 1 1 1 50 0.7 0.8 0.9 1 1.1 1.1 60 0.8 0.9 1 1.1 1.2 1.2 80 1 1 1 1.2 1.2 1.2 100 1 1 1 1.3 1.3 1.3 140 1 1 1 1.3 1.3 1.3

[0280] In Table 8, W represents the accelerator pedal opening (%), and D represents the current vehicle speed (kph). In the fifth correspondence shown in Table 7, when the accelerator pedal opening is fixed, the second correction coefficient increases with increasing current vehicle speed. Specifically, when the accelerator pedal opening is less than the third opening (e.g., 40% in Table 8) and the current vehicle speed is less than the first speed (e.g., 60 kph in Table 8), the second correction coefficient is less than 1. When the accelerator pedal opening is greater than the third opening (e.g., 40% in Table 8) and the current vehicle speed is greater than the second speed (e.g., 50 kph in Table 8), the second correction coefficient is greater than 1.

[0281] It's understandable that the greater the accelerator pedal opening, the greater the driver's power demand, or the higher the current vehicle speed. A greater power demand requires the vehicle to control the engine's torque output more quickly to meet that demand. Therefore, in the fifth correspondence, when the accelerator pedal opening is fixed, the second correction coefficient tends to increase as the current vehicle speed increases.

[0282] When the accelerator pedal opening is less than the third opening and the current vehicle speed is less than the first vehicle speed, the current power demand of the vehicle is relatively small. At this time, the engine torque can be controlled to increase based on a small gradient. Therefore, in the fifth correspondence, when the accelerator pedal opening is less than the third opening and the current vehicle speed is less than the first vehicle speed, the second correction coefficient is less than 1, which is used to reduce the basic torque increase gradient.

[0283] When the accelerator pedal opening is greater than the third opening and the current vehicle speed is greater than the second vehicle speed, the vehicle's current power demand is relatively high. In this case, it is necessary to control the engine torque increase based on a larger gradient to meet the driver's power demand. Therefore, in the fifth correspondence, when the accelerator pedal opening is greater than the third opening and the current vehicle speed is greater than the second vehicle speed, the second correction coefficient is greater than 1, which is used to amplify the basic torque increase gradient.

[0284] For example, if the obtained accelerator pedal opening is 60% and the current vehicle speed is 100 kph, then based on the accelerator pedal opening of 60% and the current vehicle speed of 100 kph, the second correction factor can be found in Table 8 above as 1.3.

[0285] After obtaining the basic torsional gradient, the first correction coefficient, and the second correction coefficient, the basic torsional gradient is multiplied by the first and second correction coefficients in sequence to obtain the target torsional gradient. In the above embodiment, the determined basic torsional gradient is 300 NM / s, the first correction coefficient is 0.5, and the second correction coefficient is 1.3. Therefore, the target torsional gradient = 300 * 0.5 * 1.3 = 195 NM / s.

[0286] In some embodiments, the engine comprises two parts: fire path torque and air path torque. The target torque increase gradient also includes two types: fire path torque increase gradient and air path torque increase gradient. It is necessary to determine the fire path torque increase gradient and the air path torque increase gradient separately. The engine's fire path torque is controlled to increase based on the fire path torque increase gradient, and the engine's air path torque is controlled to increase based on the air path torque increase gradient.

[0287] In the above embodiments, the process of determining the target torque gradient based on Tables 6, 7, and 8 can specifically be the process of determining the ignition path torque gradient. The process of determining the air path torque gradient is the same as that of determining the ignition path torque gradient. A basic torque gradient for the air path torque is obtained using the current engine torque and the clutch pressure. A first correction coefficient is determined based on the current engine torque and clutch pressure, and a second correction coefficient is determined based on the accelerator pedal opening and current vehicle speed. The basic torque gradient for the air path torque is then multiplied sequentially by the first and second correction coefficients to obtain the air path torque gradient.

[0288] The difference lies in the fact that, when determining the torque increase gradient of the air path, a sixth correspondence is used to find the base torque increase gradient based on the current engine torque. Similar to the third correspondence, the calibration value of the torque increase gradient of the air path torque in the sixth correspondence differs from the calibration value of the torque increase gradient of the spark plug torque in the third correspondence. During calibration, the torque increase gradient of the air path torque should be ensured to be less than or equal to the torque increase gradient of the spark plug torque.

[0289] It is understandable that, since the torque in the fire circuit usually drops to zero when the torque is reduced, while the torque in the gas circuit has a reserve torque, the torque in the fire circuit usually needs to start from a lower value during the torque increase process. In order to ensure that the torque in the fire circuit and gas circuit rise synchronously and further ensure the smoothness of the torque increase process, the torque increase gradient of the fire circuit can be set to be greater than that of the gas circuit torque.

[0290] In some embodiments, when determining the torque increase gradient of the air path, the correspondence between the first correction coefficient and the second correction coefficient is looked up, which can be the same as when determining the torque increase gradient of the obtained torque by looking up the correspondence between the first correction coefficient and the second correction coefficient.

[0291] In some embodiments, similar to the torque reduction process, in the process of controlling the actual torque increase of the engine based on the target torque increase gradient, it is usually necessary to ensure that the engine's ignition angle is always within the target adjustment range.

[0292] For example, in the above embodiment, it is necessary to keep the ignition angle within the target adjustment range [θ0, θ2]. In this embodiment, it is also necessary to keep the ignition angle within the target adjustment range [θ0, θ2]. In order to further ensure the smoothness of the torque increase process, this embodiment also needs to control the ignition angle to be as close to θ0 as possible. That is, in the process of controlling the actual torque increase of the engine based on the target torque increase gradient, the torque difference between the engine fire circuit torque and the air circuit torque should be kept as close to zero as possible.

[0293] In some embodiments, during the process of controlling the actual torque increase of the engine based on the target torque gradient, when the target air circuit torque, the target fire circuit torque and the actual torque of the engine are equal, the vehicle controller can control the release state of the ignition angle to be reset, that is, control the ignition angle to be restored to the optimal ignition angle.

[0294] As can be understood, as mentioned above, in the process of controlling the actual torque increase of the engine based on the target torque increase gradient, the ignition angle is usually kept within the target adjustment range [θ0, θ2]. When the target air circuit torque, the target spark circuit torque and the actual torque of the engine are equal, it usually means that the torque increase target has been achieved and the air and spark circuit torques have been synchronized. At this time, it is no longer necessary to control the release of the ignition angle, and the ignition angle can be restored to the initial state, that is, the ignition angle is controlled to be restored to the optimal ignition angle.

[0295] Figure 4 This is a schematic diagram of the structure of a gear switching device provided in an embodiment of this application.

[0296] For example, such as Figure 4 As shown, the device 400 includes:

[0297] The first determining module 401 is used to determine the vehicle drive power and the power battery discharge power corresponding to the direct drive mode if it is determined that the vehicle needs to switch gears during the process of driving the vehicle in direct drive mode.

[0298] The second determining module 402 is used to determine the target torque reduction gradient based on the vehicle's driving power, discharge power, and the vehicle's gear change status.

[0299] The first control module 403 is used to control the actual torque of the engine to decrease to the target torque based on the target torque reduction gradient;

[0300] The second control module 404 is used to control the clutch to be in the open state when the actual torque of the engine is equal to the target torque, so that the vehicle can shift gears when the clutch is in the open state.

[0301] In one possible implementation, the second determining module 402 is specifically used to: determine a first torque reduction gradient as a target torque reduction gradient when the vehicle's driving power is less than or equal to the discharge power and the vehicle's gear shift state is upshifting; determine a second torque reduction gradient as a target torque reduction gradient when the vehicle's driving power is less than or equal to the discharge power and the vehicle's gear shift state is downshifting; wherein the first torque reduction gradient is less than the second torque reduction gradient; determine a third torque reduction gradient as a target torque reduction gradient when the vehicle's driving power is greater than the discharge power and the vehicle's gear shift state is upshifting; wherein the third torque reduction gradient is less than the first torque reduction gradient; and determine a fourth torque reduction gradient as a target torque reduction gradient when the vehicle's driving power is greater than the discharge power and the vehicle's gear shift state is downshifting; wherein the fourth torque reduction gradient is less than the second torque reduction gradient and greater than the third torque reduction gradient.

[0302] In one possible implementation, the second determining module 402 is specifically used to: obtain the original air circuit torque request value of the engine and the current opening of the vehicle's accelerator pedal; determine the target correspondence based on the vehicle's driving power, discharge power and the vehicle's gear change status; and find the target correspondence based on the original air circuit torque request value, accelerator pedal opening, vehicle driving power and discharge power to obtain the target torque reduction gradient.

[0303] In one possible implementation, the target correspondence includes a first correspondence and a second correspondence. The second determining module 402 is specifically used to: calculate the power difference between the vehicle's driving power and the discharge power; find the first correspondence based on the original air circuit torque request value and the power difference to obtain the basic torque reduction gradient; find the second correspondence based on the accelerator pedal opening and the power difference to obtain the first target correction coefficient; and determine the target torque reduction gradient based on the basic torque reduction gradient and the first target correction coefficient.

[0304] In one possible implementation, the second determining module 402 is specifically used to: multiply the basic torque reduction gradient and the first target correction coefficient to obtain the target fire path torque reduction gradient; and correct the target fire path torque reduction gradient based on the second target correction coefficient to obtain the target gas path torque reduction gradient; wherein the target fire path torque reduction gradient is greater than the target gas path torque reduction gradient; and the second target correction coefficient is used to control the absolute value of the torque difference between the reduced fire path torque and the reduced gas path torque to be less than or equal to a preset difference.

[0305] Optionally, the device 400 further includes: a third determining module, used to determine the original air circuit torque request value based on the driver's required torque, the target front and rear axle torque distribution ratio, and the actual torque of the target motor; to determine the target fire circuit torque based on the original air circuit torque request value, the shift intervention torque, and the engine fire circuit speed control torque; and to determine the target air circuit torque based on the original air circuit torque request value, the engine air circuit torque reserve, the engine air circuit speed control torque reserve, and the target fire circuit torque.

[0306] In one possible implementation, the target torque reduction gradient includes a target fire path torque reduction gradient and a target air path torque reduction gradient, and the target torque includes a target fire path torque and a target air path torque, wherein the target air path torque is greater than the target fire path torque. The first control module 403 is specifically used to: control the engine's fire path torque to decrease to the target fire path torque according to the target fire path torque reduction gradient; during the process of controlling the engine's fire path torque to decrease according to the target fire path torque reduction gradient, control the engine's air path torque to decrease to the target air path torque according to the target air path torque reduction gradient, so as to ensure that the absolute value of the torque difference between the reduced fire path torque and the reduced air path torque is less than or equal to a preset difference, and to ensure that the engine's ignition angle is within the target adjustment range.

[0307] Optionally, the device 400 further includes: a third control module, configured to determine the target number of cylinders to be cut off in the engine based on the target fire torque and the target torque range of a single cylinder if the fire torque after the control of the engine's fire torque is reduced according to the target fire torque reduction gradient does not reach the target fire torque; wherein the target torque range of a single cylinder is determined based on the target adjustment range of the ignition angle; and to perform cylinder cut-off processing on the cylinders corresponding to the target number of cylinders to be cut off in the engine so that the fire torque is reduced to the target fire torque value.

[0308] Optionally, the device 400 further includes: a fourth control module, used to control the speed difference between the two ends of the clutch to decrease when the vehicle completes gear shifting; control the clutch to be in a closed state when the speed difference between the two ends of the clutch is less than or equal to a preset speed difference; determine a target torque increase gradient when the clutch is in a closed state; and control the actual torque of the engine to increase based on the target torque increase gradient so that the engine drives the vehicle.

[0309] In one possible implementation, the fourth control module is specifically used to: acquire the current engine speed, current engine torque, clutch pressure, accelerator pedal opening, and current vehicle speed; determine a basic torque increase gradient based on the current engine speed and current engine torque; determine a first correction coefficient based on the current engine torque and clutch pressure; determine a second correction coefficient based on the accelerator pedal opening and current vehicle speed; and determine a target torque increase gradient by combining the basic torque increase gradient, the first correction coefficient, and the second correction coefficient.

[0310] Figure 5 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application.

[0311] For example, such as Figure 5 As shown, the vehicle 500 includes a memory 501 and a processor 502. The memory 501 stores executable program code 5011, and the processor 502 is used to call and execute the executable program code 5011 to perform a gear shifting method.

[0312] Furthermore, this application also protects an apparatus that may include a memory and a processor, wherein the memory stores executable program code, and the processor is used to call and execute the executable program code to perform a gear switching method provided in this application.

[0313] This embodiment can divide the device into functional modules based on the above method example. For example, each module can correspond to a separate function, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0314] When each functional module is divided according to its corresponding function, the device may further include a first determining module, a second determining module, a first control module, and a second control module. It should be noted that all relevant content regarding the steps involved in the above method embodiments can be referenced from the functional descriptions of the corresponding functional modules, and will not be repeated here.

[0315] It should be understood that the device provided in this embodiment is used to execute the above-described gear switching method, and therefore can achieve the same effect as the above-described implementation method.

[0316] When using 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 can be used to control and manage the vehicle's movements. The storage module can be used to support the vehicle in executing relevant program code.

[0317] The processing module may be a processor or a controller, which can implement or execute various exemplary logic blocks, modules, and circuits shown in conjunction with the disclosure of this application. The processor may also be a combination of functions that implement computing capabilities, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc., and the storage module may be a memory.

[0318] In addition, the device provided in the embodiments of this application may specifically be a chip, component or module. The chip may include a connected processor and a memory. The memory is used to store instructions. When the processor calls and executes the instructions, the chip can execute a gear switching method provided in the above embodiments.

[0319] This embodiment also provides a computer-readable storage medium storing computer program code. When the computer program code is run on a computer, the computer executes the aforementioned method steps to implement the gear switching method provided in the above embodiment.

[0320] This embodiment also provides a computer program product that, when run on a computer, causes the computer to perform the aforementioned related steps to implement a gear switching method provided in the above embodiment.

[0321] In this embodiment, the device, computer-readable storage medium, computer program product, or chip are all used to execute the corresponding methods provided above. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects in the corresponding methods provided above, and will not be repeated here.

[0322] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above 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.

[0323] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0324] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for shifting gears, characterized in that, The method includes: During the driving of the vehicle in direct drive mode, if it is determined that the vehicle needs to switch gears, the total vehicle drive power and the discharge power of the power battery corresponding to the direct drive mode are determined. Based on the vehicle's driving power, the discharge power, and the vehicle's gear shift status, the target torque reduction gradient is determined. Based on the target torque reduction gradient, the actual torque of the engine is controlled to be reduced to the target torque; When the actual torque of the engine is equal to the target torque, the clutch is controlled to be in the open state so that the vehicle can shift gears when the clutch is in the open state.

2. The method according to claim 1, characterized in that, Determining the target torque reduction gradient based on the vehicle's drive power, discharge power, and gear shift status includes: When the total vehicle driving power is less than or equal to the discharge power and the vehicle's gear shift state is upshifting, the first torque reduction gradient is determined as the target torque reduction gradient. When the overall vehicle driving power is less than or equal to the discharge power and the vehicle's gear shift state is downshifting, the second torque reduction gradient is determined as the target torque reduction gradient; wherein, the first torque reduction gradient is less than the second torque reduction gradient; When the overall vehicle driving power is greater than the discharge power and the vehicle's gear shift state is upshifting, the third torque reduction gradient is determined as the target torque reduction gradient; wherein, the third torque reduction gradient is less than the first torque reduction gradient; When the overall vehicle driving power is greater than the discharge power and the vehicle's gear shift state is downshifting, the fourth torque reduction gradient is determined as the target torque reduction gradient; wherein the fourth torque reduction gradient is less than the second torque reduction gradient and the fourth torque reduction gradient is greater than the third torque reduction gradient.

3. The method according to claim 1, characterized in that, Determining the target torque reduction gradient based on the vehicle's drive power, discharge power, and gear shift status includes: Obtain the original airflow torque request value of the engine and the current opening of the accelerator pedal of the vehicle; Based on the vehicle's driving power, the discharge power, and the vehicle's gear shift status, the target correspondence is determined; Based on the original air circuit torque request value, accelerator pedal opening, vehicle drive power and discharge power, the target correspondence is found to obtain the target torque reduction gradient.

4. The method according to claim 3, characterized in that, The target correspondence includes a first correspondence and a second correspondence. The step of finding the target correspondence based on the original air circuit torque request value, accelerator pedal opening, vehicle drive power, and discharge power to obtain the target torque reduction gradient includes: Calculate the power difference between the vehicle drive power and the discharge power; Based on the original air path torque request value and the power difference, the first correspondence is found to obtain the basic torque reduction gradient; Based on the accelerator pedal opening and the power difference, the second correspondence is found to obtain the first target correction coefficient; The target torque reduction gradient is determined based on the basic torque reduction gradient and the first target correction coefficient.

5. The method according to claim 4, characterized in that, The target torque reduction gradient includes the target fire path torque reduction gradient and the target gas path torque reduction gradient. Determining the target torque reduction gradient based on the basic torque reduction gradient and the first target correction coefficient includes: Multiply the base torque reduction gradient by the first target correction coefficient to obtain the target fire path torque reduction gradient; Based on the second target correction coefficient, the target fire path torque reduction gradient is corrected to obtain the target gas path torque reduction gradient; wherein, the target fire path torque reduction gradient is greater than the target gas path torque reduction gradient; the second target correction coefficient is used to control the absolute value of the torque difference between the reduced fire path torque and the reduced gas path torque to be less than or equal to a preset difference.

6. The method according to any one of claims 1 to 5, characterized in that, The target torque includes the target fire circuit torque and the target gas circuit torque, and the target torque is determined by the following method: The original air circuit torque request value is determined based on the driver's required torque, the target front and rear axle torque distribution ratio, and the actual torque of the target motor. The target firing torque is determined based on the original air circuit torque request value, the shift intervention torque, and the engine firing circuit speed control torque. Based on the original gas path torque request value, the engine gas path torque reserve, the engine gas path speed control torque reserve, and the target fire path torque, the target gas path torque is determined.

7. The method according to any one of claims 1 to 5, characterized in that, The target torque reduction gradient includes a target fire path torque reduction gradient and a target air path torque reduction gradient. The target torque includes a target fire path torque and a target air path torque. The target air path torque is greater than the target fire path torque. Controlling the engine's actual torque to reduce to the target torque based on the target torque reduction gradient includes: The engine's firing torque is controlled to decrease to the target firing torque according to the target firing torque reduction gradient; During the process of controlling the engine's fire circuit torque to decrease according to the target fire circuit torque reduction gradient, the engine's air circuit torque is controlled to decrease to the target air circuit torque according to the target air circuit torque reduction gradient, so as to ensure that the absolute value of the torque difference between the reduced fire circuit torque and the reduced air circuit torque is less than or equal to a preset difference, and to ensure that the engine's ignition angle is within the target adjustment range.

8. The method according to claim 7, characterized in that, The method further includes: If the controlled firing torque of the engine, after being reduced according to the target firing torque reduction gradient, does not reach the target firing torque, then the target number of cylinders in the engine is determined based on the target firing torque and the target torque range of a single cylinder; wherein, the target torque range of a single cylinder is determined based on the target adjustment range of the ignition angle. The cylinders corresponding to the target number of cylinders cut off in the engine are subjected to cylinder cut-off treatment so that the fire circuit torque is reduced to the target fire circuit torque value.

9. The method according to any one of claims 1 to 5, characterized in that, After the control clutch is in the open state, causing the vehicle to shift gears while the clutch is in the open state, the method further includes: When the vehicle completes a gear shift, the speed difference between the two ends of the clutch is reduced. When the speed difference between the two ends of the clutch is less than or equal to a preset speed difference, the clutch is controlled to be in a closed state. With the clutch in the engaged state, the target torque gradient is determined; The engine's actual torque is increased based on the target torque gradient, so that the engine drives the vehicle.

10. The method according to claim 9, characterized in that, Determining the target lift-torque gradient includes: The engine's current speed, engine's current torque, clutch pressure, accelerator pedal opening, and current vehicle speed are obtained. The base torque gradient is determined based on the engine's current speed and current torque. A first correction factor is determined based on the current torque of the engine and the pressure of the clutch; Based on the accelerator pedal opening and the current vehicle speed, a second correction coefficient is determined; The target torque gradient is determined by the base torque gradient, the first correction coefficient, and the second correction coefficient.

11. A vehicle, characterized in that, The vehicles include: Memory, used to store executable program code; A processor for calling and running the executable program code from the memory, causing the vehicle to perform the method as described in any one of claims 1 to 10.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed, implements the method as described in any one of claims 1 to 10.

Images