A control method of a vehicle, a vehicle, and a storage medium

Abstract

The application provides a control method of a vehicle, a vehicle and a storage medium, and belongs to the technical field of hybrid control. The method comprises the following steps: in the case that a first clutch is in a closed state, determining a current output torque of a first motor based on a current output torque of an engine, then controlling the absolute value of the current output torque of the first motor to decrease to a target output torque according to a target torque decreasing gradient, and simultaneously controlling a second motor to output a corresponding target compensation torque to inhibit torque disturbance caused by the absolute value of the torque of the first motor decreasing during the process of controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque decreasing gradient. The method can effectively inhibit torque disturbance caused by the absolute value of the torque of the first motor decreasing, and effectively improve the running smoothness and the driving comfort of the vehicle.

Description

Technical Field

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

[0002] In hybrid power systems, there are situations where different operating modes can be switched between each other. During the switching of operating modes, it may be necessary to control the reduction of motor torque.

[0003] However, existing torque reduction control methods have complex calculation processes, may contain certain errors during calculation, and are prone to torque disturbances, resulting in poor vehicle stability. Summary of the Invention

[0004] This application provides a vehicle control method, a vehicle, and a storage medium. The method can effectively suppress torque disturbances caused by a decrease in the absolute value of the torque of a first motor, thereby effectively improving the smoothness of vehicle operation and driving comfort.

[0005] In a first aspect, a vehicle control method is provided, applicable to a hybrid vehicle. The vehicle includes an engine, a first electric motor, a planetary gear set, a first clutch, a second electric motor, and a differential. The engine is connected to the first electric motor via the planetary gear set, the first clutch is connected to the planetary gear set, and the second electric motor is connected to the differential. The method includes: with the first clutch in a closed state, determining the current output torque of the first electric motor based on the current output torque of the engine; controlling the absolute value of the current output torque of the first electric motor to decrease to a target output torque according to a target torque reduction gradient; and during the process of controlling the absolute value of the current output torque of the first electric motor to decrease to the target output torque according to the target torque reduction gradient, controlling the second electric motor to output a corresponding target compensation torque to suppress torque disturbances caused by the decrease in the absolute value of the torque of the first electric motor.

[0006] The above technical solution, with the first clutch in the closed state, determines the current output torque of the first motor based on the current output torque of the engine, and controls the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient. This effectively reduces the fluctuations caused by sudden torque changes during the torque reduction of the first motor, avoids shock and vibration in the transmission system, and this control method is simple and easy to implement, effectively reducing the computational load on the controller. At the same time, during the process of controlling the absolute value of the current output torque of the first motor to decrease, the second motor can be simultaneously controlled to output the corresponding target compensation torque to counteract the torque disturbance caused by the decrease in the absolute value of the torque of the first motor, thereby stabilizing the wheel-end output torque of the whole vehicle. During the process of controlling the absolute value of the torque of the first motor to decrease, the wheel-end torque is kept without significant fluctuations, effectively improving the smoothness of vehicle operation and ride comfort.

[0007] In conjunction with the first aspect, in some implementations of the first aspect, the planetary gear set includes a sun gear, a planet carrier, and a ring gear. The sun gear is connected to a first motor, the planet carrier is connected to an engine, and the ring gear is connected to the vehicle's power output shaft. Determining the current output torque of the first motor based on the current output torque of the engine includes: obtaining a preset ring gear ratio; wherein the preset ring gear ratio is the ratio between the number of teeth on the ring gear and the number of teeth on the sun gear; and determining the current output torque of the first motor based on the current output torque of the engine and the preset ring gear ratio.

[0008] In combination with the first aspect and the above implementation methods, in some implementation methods of the first aspect, the target torque reduction gradient is determined by the following method: obtaining the torque difference between the current output torque of the first motor and the target output torque, and obtaining the current output torque of the engine; determining a first correction coefficient based on the absolute value of the torque difference, and determining a second correction coefficient based on the current output torque of the engine; and correcting the basic torque reduction gradient based on the first correction coefficient and the second correction coefficient to obtain the target torque reduction gradient.

[0009] The above technical solution matches a first correction coefficient with the torque difference between the current output torque of the first motor and the target output torque, and matches a second correction coefficient with the current output torque of the engine. This allows for a dual correction of the basic torque reduction gradient based on the first and second correction coefficients. When determining the target torque reduction gradient, both the torque difference and the engine load are fully considered. This is equivalent to adaptively adjusting the rate of decrease of the absolute value of the output torque of the first motor according to the torque difference and the current output torque of the engine. This significantly improves the smoothness of the transmission system during torque reduction while ensuring the torque adjustment response speed.

[0010] In conjunction with the first aspect and the above implementation methods, in some implementation methods of the first aspect, the target torque reduction gradient includes a first torque reduction gradient and a second torque reduction gradient. The absolute values ​​of the first torque reduction gradient and the second torque reduction gradient are not equal. Controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient includes: when the absolute value of the real-time torque difference between the current output torque and the target output torque of the first motor is within a first torque range, controlling the absolute value of the current output torque to decrease according to the first torque reduction gradient until the absolute value of the real-time torque difference is within a second torque range; wherein, the lower limit of the first torque range is equal to the upper limit of the second torque range; when the absolute value of the real-time torque difference is within the second torque range, controlling the absolute value of the current output torque of the first motor to continue to decrease according to the second torque reduction gradient until the current output torque of the first motor is reduced to the target output torque.

[0011] The above technical solution divides the torque range into two interconnected ranges and matches a first torque reduction gradient and a second torque reduction gradient with unequal absolute values ​​to the two torque ranges respectively. Then, when the absolute value of the real-time torque difference between the current output torque and the target output torque of the first motor is in different torque ranges, the output torque of the first motor is controlled to decrease in segments according to different torque reduction gradients. By configuring the relative magnitude of the two torque reduction gradients, it can flexibly adapt to two torque reduction strategies: fast first and then slow, or slow first and then fast, thereby improving the flexibility and adaptability of the torque adjustment process.

[0012] In conjunction with the first aspect and the above-described implementations, in some implementations of the first aspect, before controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient, the method further includes: calculating the initial torque difference between the current output torque of the first motor and the target output torque; multiplying the absolute value of the initial torque difference by a preset ratio to obtain a torque threshold; determining the torque range in which the absolute value of the torque difference between the current output torque of the first motor and the target output torque is greater than the torque threshold as a first torque range, and determining the torque range in which the absolute value of the torque difference between the current output torque of the first motor and the target output torque is less than or equal to the threshold as a second torque range.

[0013] Combining the first aspect and the above-mentioned implementation methods, in some implementation methods of the first aspect, the planetary gear set includes a sun gear, a planet carrier, and a ring gear. The sun gear is connected to the first motor, the planet carrier is connected to the engine, and the ring gear is connected to the second motor. The method further includes: during the process of controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient, determining the torque change of the ring gear based on the torque change of the first motor; and determining the target compensation torque of the second motor based on the torque change of the ring gear.

[0014] In conjunction with the first aspect and the above-mentioned implementation methods, in some implementation methods of the first aspect, determining the torque change of the gear ring based on the torque change of the first motor includes: obtaining a preset gear ring ratio; wherein the preset gear ring ratio is the ratio between the number of teeth of the gear ring and the number of teeth of the sun gear; and determining the torque change of the gear ring based on the torque change of the first motor and the preset gear ring ratio.

[0015] In combination with the first aspect and the above implementation methods, in some implementation methods of the first aspect, the target compensation torque of the second motor is determined based on the torque change of the gear ring, including: obtaining the transmission ratio of the vehicle's main reducer and the transmission efficiency of the gear ring; multiplying the torque change of the gear ring, the transmission ratio of the main reducer, and the transmission efficiency of the gear ring to obtain the converted torque change; and determining the negative value of the converted torque change as the target compensation torque of the second motor.

[0016] The above technical solution incorporates the transmission efficiency of the gear ring during the calculation of the target compensation torque of the second motor, thereby obtaining the effective disturbance torque after removing transmission losses. Simultaneously, by combining the transmission ratio of the main reducer, the torque disturbance at the gear ring end can be accurately converted into the equivalent actual disturbance torque at the wheel end. This effectively reduces errors in the torque transmission path and improves the calculation accuracy of the target compensation torque. Based on the negative value of the converted actual disturbance torque, controlling the output compensation torque of the second motor can accurately counteract the disturbance torque transmitted from the gear ring to the wheel, thereby suppressing the torque disturbance caused by the torque drop of the first motor and improving the vehicle's driving stability.

[0017] Secondly, a vehicle control device is provided, applicable to a hybrid vehicle. The vehicle includes an engine, a first electric motor, a planetary gear set, a first clutch, a second electric motor, and a differential. The engine is connected to the first electric motor via the planetary gear set, the first clutch is connected to the planetary gear set, and the second electric motor is connected to the differential. The device includes: a determining module, used to determine the current output torque of the first electric motor based on the current output torque of the engine when the first clutch is engaged; a first control module, used to control the absolute value of the current output torque of the first electric motor to decrease to a target output torque according to a target torque reduction gradient; and a second control module, used to control the second electric motor to output a corresponding target compensation torque during the process of controlling the absolute value of the current output torque of the first electric motor to decrease to the target output torque according to the target torque reduction gradient, so as to suppress torque disturbances caused by the decrease in the absolute value of the torque of the first electric motor.

[0018] In conjunction with the second aspect, in some implementations of the second aspect, the planetary gear set includes a sun gear, a planet carrier, and a ring gear. The sun gear is connected to the first motor, the planet carrier is connected to the engine, and the ring gear is connected to the vehicle's power output shaft. The determining module is specifically used to: obtain a preset ring gear ratio; wherein, the preset ring gear ratio is the ratio between the number of teeth on the ring gear and the number of teeth on the sun gear; and determine the current output torque of the first motor based on the current output torque of the engine and the preset ring gear ratio.

[0019] In conjunction with the second aspect and the above implementation methods, in some implementation methods of the second aspect, the device further includes a gradient determination module, which is specifically used to: obtain the torque difference between the current output torque of the first motor and the target output torque, and obtain the current output torque of the engine; determine a first correction coefficient based on the absolute value of the torque difference, and determine a second correction coefficient based on the current output torque of the engine; and correct the basic torque reduction gradient based on the first correction coefficient and the second correction coefficient to obtain the target torque reduction gradient.

[0020] Combining the second aspect and the above implementation methods, in some implementation methods of the second aspect, the target torque reduction gradient includes a first torque reduction gradient and a second torque reduction gradient. The absolute values ​​of the first torque reduction gradient and the second torque reduction gradient are not equal. The first control module is specifically used to: when the absolute value of the real-time torque difference between the current output torque of the first motor and the target output torque is within the first torque range, control the absolute value of the current output torque to decrease according to the first torque reduction gradient until the absolute value of the real-time torque difference is within the second torque range; wherein, the lower limit of the first torque range is equal to the upper limit of the second torque range; when the absolute value of the real-time torque difference is within the second torque range, control the absolute value of the current output torque of the first motor to continue to decrease according to the second torque reduction gradient until the current output torque of the first motor is reduced to the target output torque.

[0021] In conjunction with the second aspect and the above-described implementations, in some implementations of the second aspect, the device further includes a torque range determination module, which is specifically used to: calculate the initial torque difference between the current output torque of the first motor and the target output torque; multiply the absolute value of the initial torque difference by a preset ratio to obtain a torque threshold; determine the torque range in which the absolute value of the torque difference between the current output torque of the first motor and the target output torque is greater than the torque threshold as the first torque range, and determine the torque range in which the absolute value of the torque difference between the current output torque of the first motor and the target output torque is less than or equal to the threshold as the second torque range.

[0022] In conjunction with the second aspect and the above-described implementations, in some implementations of the second aspect, the planetary gear set includes a sun gear, a planet carrier, and a ring gear. The sun gear is connected to the first motor, the planet carrier is connected to the engine, and the ring gear is connected to the second motor. The device also includes a second determining module, which is specifically used to: determine the torque change of the ring gear based on the torque change of the first motor during the process of controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient; and determine the target compensation torque of the second motor based on the torque change of the ring gear.

[0023] In conjunction with the second aspect and the above implementation methods, in some implementation methods of the second aspect, the second determining module includes a first determining unit, which is specifically used for: obtaining a preset gear ratio; wherein the preset gear ratio is the ratio between the number of teeth of the gear ring and the number of teeth of the sun gear; and determining the torque change of the gear ring based on the torque change of the first motor and the preset gear ratio.

[0024] In conjunction with the second aspect and the above implementation methods, in some implementation methods of the second aspect, the second determining module includes a second determining unit, which is specifically used for: obtaining the transmission ratio of the vehicle's main reducer and the transmission efficiency of the gear ring; multiplying the torque change of the gear ring, the transmission ratio of the main reducer, and the transmission efficiency of the gear ring to obtain the converted torque change; and determining the negative value of the converted torque change as the target compensation torque of the second motor.

[0025] 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 vehicle control methods of the first aspect and any possible implementation thereof.

[0026] Fourthly, a computer program product is provided, comprising: computer program code, which, when run on a computer, causes the computer to execute the vehicle control method of the first aspect and any possible implementation thereof.

[0027] 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 vehicle control method of the first aspect and any possible implementation thereof. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of a hybrid vehicle provided in an embodiment of this application; Figure 2This is a schematic flowchart of a vehicle control method provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a vehicle control device provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application. Detailed Implementation

[0029] 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.

[0030] 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.

[0031] In hybrid power systems, there are situations where different operating modes can be switched between each other. During the switching of operating modes, it may be necessary to control the reduction of motor torque.

[0032] Figure 1 This is a schematic diagram of the structure of a hybrid vehicle provided in an embodiment of this application.

[0033] For example, such as Figure 1 As shown, a hybrid vehicle may include: a first motor 101, a planetary gear set 102, and a first clutch (i.e., Figure 1 S1) 103, engine 104, second motor 105, second clutch (i.e. Figure 1 S2)106 and differential 107.

[0034] The first motor 101 is also called a GM motor (Generator Motor). The first motor is connected to the engine 104 via a planetary gear set 102 and can be used to start the engine or driven by the engine to function as a generator. In some cases, the first motor 101 can also act as a drive motor, assisting the engine 104 in outputting power to drive the vehicle.

[0035] The planetary gear set 102 includes a planet carrier 1021, a sun gear 1022, and a ring gear 1023. Specifically, a first motor 101 is connected to the sun gear 1022 of the planetary gear set 102, and a second motor 105 is connected to the ring gear 1023. The ring gear 1023 can also be connected to the vehicle's output shaft to ensure that the output power of the ring gear 1023 is used to drive the vehicle wheels. An engine 104 is connected to the planet carrier 1021 of the planetary gear set 102. The ring gear 1023 of the planetary gear set 102 is connected to a differential 107 for outputting power to drive the vehicle.

[0036] The first clutch (S1) 103 is connected to the planetary gear set 102. Specifically, one side of the first clutch (S1) 103 is connected to the planet carrier 1021, and the other side can be selectively connected to the ring gear 1023 or the sun gear 1022. If one side of the first clutch 103 is connected to the planet carrier 1021 and the other side is connected to the ring gear 1023, then... Figure 1 As shown, closing the first clutch 103 will lock the ring gear 1023 to the planetary carrier 1021; conversely, if one side of the first clutch 103 is connected to the planetary carrier 1021 and the other side is connected to the sun gear 1022, closing the first clutch 103 will lock the sun gear 1022 to the planetary carrier 1021. In summary, regardless of whether the other side of the first clutch 103 is connected to the ring gear 1023 or the sun gear 1022, when the first clutch 103 is closed, the planetary gear set 102 will be locked as a whole due to the locking of the two components. At this time, all the power of the engine 104 is transmitted to the ring gear 1023. When the first clutch 103 is open, the power output by the engine 104 is transmitted through the planetary carrier 1021, partly to the first motor 101 and partly to the ring gear 1023.

[0037] The second motor 105, also called the TM motor (Traction Motor), is connected to the differential 107 via the second clutch 106 and is used to output power to the differential 107 to drive the vehicle.

[0038] The second clutch 106 is used to disconnect or connect the mechanical connection between the second motor 105 and the differential 107. Specifically, when the second clutch 106 is in the closed state, the second motor 105 and the differential 107 are mechanically connected, and the second motor 105 can output power to drive the vehicle. When the second clutch 106 is in the open state, the second motor 105 and the differential 107 are disconnected.

[0039] The differential 107 is used to allow the left and right wheels to rotate at different speeds when the vehicle is turning. With the differential 107, the outer wheel can rotate at a faster speed and the inner wheel can rotate at a slower speed, ensuring smooth turning of the vehicle.

[0040] The inventors of this application discovered through research that in hybrid vehicles (such as...) Figure 1 In the hybrid vehicle shown, after the first clutch is engaged, the vehicle's operating mode switches to mechanical direct drive mode. At this time, the planetary gear set is locked, the engine and the first electric motor are mechanically connected, and the engine and wheels are mechanically connected. All the power output from the engine is transmitted to the vehicle's wheels through the locked planetary gear set to drive the vehicle. Before the first clutch is engaged, the first electric motor may be in a generator state. After the first clutch is engaged, to reduce motor losses, the absolute value of the first electric motor's torque is usually reduced to the target torque.

[0041] However, existing torque reduction control methods have complex calculation processes, may contain certain errors, and are prone to torque disturbances, resulting in poor vehicle stability.

[0042] For example, existing technologies typically employ a "zero torque control" process to reduce the absolute value of the first motor's torque to the target torque. Specifically, this involves: first, obtaining the engine's required torque and actual output torque; then, calculating and locking the torque deviation between the engine's required torque and actual output torque; next, combining the planetary gear transmission relationship with the speed difference before clutch engagement to calculate the speed balancing torque; finally, superimposing the torque deviation compensation, speed balancing torque, and auxiliary torque to generate the torque command for the first motor. Through closed-loop regulation, the output torque of the first motor is converged to zero, eliminating ineffective work by the first motor and reducing its operating losses.

[0043] As can be seen, the aforementioned "zero torque control" process involves multiple computational layers and complex overall calculation logic. Furthermore, the introduction of an auxiliary torque term further increases the computational load, not only burdening the vehicle controller but also complicating software calibration. Simultaneously, the auxiliary torque value relies on empirical calibration; improper matching can easily disrupt the original torque balance of the transmission system, leading to torque fluctuations and subsequent transmission system vibration, thus affecting the overall vehicle's operational stability.

[0044] To address the aforementioned technical problems, this application provides a vehicle control method. The method is executed by the vehicle itself, specifically by a controller within the vehicle. This method controls the absolute value of the current output torque of a first motor to decrease to a target output torque according to a target torque reduction gradient. Simultaneously, while controlling the decrease in the torque of the first motor, it also synchronously controls the output of a second motor to output a corresponding target compensation torque. This effectively suppresses torque disturbances caused by the decrease in the absolute value of the first motor's torque, thereby significantly improving the smoothness of vehicle operation and ride comfort.

[0045] Figure 2This is a schematic flowchart of a vehicle control method provided in an embodiment of this application.

[0046] For example, this method can be specifically applied to the hybrid control unit (HCU) in a hybrid vehicle.

[0047] Optionally, the above Figure 2 The method shown can be applied to Figure 1 The hybrid vehicle shown can also be applied to other dual-motor hybrid vehicles equipped with planetary gear sets; this application does not limit this application. The following embodiments use… Figure 2 The method shown is applied to Figure 1 The hybrid vehicle shown is used as an example for illustration.

[0048] like Figure 2 As shown, the method 200 includes: Step 201: With the first clutch in the closed state, determine the current output torque of the first motor based on the current output torque of the engine.

[0049] Step 202: Control the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient.

[0050] Step 203: During the process of controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient, the second motor is controlled to output the corresponding target compensation torque to suppress the torque disturbance caused by the decrease in the absolute value of the torque of the first motor.

[0051] In this embodiment, when the first clutch is engaged, the current output torque of the first motor is determined based on the current output torque of the engine, and the absolute value of the current output torque of the first motor is controlled to decrease to the target output torque according to the target torque reduction gradient. This effectively reduces the fluctuations caused by sudden torque changes during the torque reduction of the first motor, avoids shock and vibration in the transmission system, and this control method is simple and easy to implement, effectively reducing the computational load on the controller. At the same time, during the process of controlling the absolute value of the current output torque of the first motor to decrease, the second motor can also be controlled to output the corresponding target compensation torque to counteract the torque disturbance caused by the decrease in the absolute value of the torque of the first motor, thereby stabilizing the wheel-end output torque of the whole vehicle. During the process of controlling the absolute value of the torque of the first motor to decrease, the wheel-end torque is kept stable without significant fluctuations, effectively improving the smoothness of vehicle operation and driving comfort.

[0052] The following is combined Figure 1 right Figure 2 The specific implementation methods of each step in the illustrated embodiment are explained below: In step 201, when a switching command is received to switch the vehicle's operating mode to mechanical direct drive mode, the first clutch can be controlled to be in a closed state. When the first clutch is in a closed state, in order to reduce motor losses, the current output torque of the first motor can usually be controlled to converge to zero. Specifically, the current output torque of the first motor can be determined first, and then adjusted until it approaches zero torque.

[0053] As mentioned above, in such Figure 1 In the hybrid vehicle shown, the planetary gear set includes a sun gear, a planet carrier, and a ring gear. The sun gear is connected to the first electric motor, the planet carrier is connected to the engine, and the ring gear is connected to the vehicle's power output shaft. The torque balance relationship of this planetary gear set structure is shown in the following formula (1): Formula (1) In the above formula (1), This refers to the output torque of the first motor (i.e., the torque of the sun gear). This refers to the torque of the gear ring (which is usually applied to the wheel end). This refers to the engine's output torque; K refers to the ratio between the number of teeth on the ring gear and the number of teeth on the sun gear, which is a characteristic coefficient of the planetary gear set.

[0054] For example, referring to the above formula (1), the current output torque of the first motor can be determined based on the current output torque of the engine.

[0055] In some embodiments, determining the current output torque of the first motor based on the current output torque of the engine includes: obtaining a preset gear ratio; wherein the preset gear ratio is the ratio between the number of teeth on the gear ring and the number of teeth on the sun gear; and determining the current output torque of the first motor based on the current output torque of the engine and the preset gear ratio.

[0056] Specifically, the above formula (1) can be transformed to obtain the formula for calculating the current output torque of the first motor, as shown in the following formula (2): Formula (2) In the above formula (2), This refers to the output torque of the first motor; This refers to the engine's output torque; K refers to the ratio between the number of teeth on the ring gear and the number of teeth on the sun gear, which is a characteristic coefficient of the planetary gear set, i.e., the preset ring gear ratio mentioned above.

[0057] Furthermore, after obtaining the current output torque of the engine and the preset gear ratio, the current output torque of the engine and the preset gear ratio can be substituted into the above formula (2) to calculate the current output torque of the first motor.

[0058] The current output torque of the engine is calculated in real time by the HCU based on the engine's operating parameters such as fuel injection quantity, current speed, and intake air volume.

[0059] The aforementioned preset gear ratio is an inherent characteristic parameter of the planetary gear set, specifically the ratio between the number of teeth on the gear ring and the number of teeth on the sun gear.

[0060] For example, assuming the current output torque of the engine is 500 Nm and the preset gear ratio is 3, the current output torque of the engine and the preset gear ratio can be substituted into the above formula (2) to obtain the current output torque of the first motor as -500 / (1+3)=-125 Nm.

[0061] In step 202, it can be understood that when the first clutch is in the closed state, the planetary gear set is locked, the engine and the first motor are mechanically connected, the engine and the wheel are mechanically connected, and all the power output by the engine is transmitted to the vehicle wheel end through the locked planetary gear set to drive the vehicle. If the first motor continues to output negative torque to generate electricity at this time, unnecessary energy consumption may occur. Therefore, the absolute value of the current output torque of the first motor can be controlled to be reduced to the target output torque (usually set to zero), that is, the negative torque currently output by the first motor is controlled to converge to zero.

[0062] However, directly controlling the current output torque of the first motor to converge to zero in a step might cause significant transmission torque disturbances, resulting in transmission system shocks and vibrations, sudden changes in wheel-end torque, and affecting the smoothness of vehicle operation and ride comfort. Therefore, a target torque reduction gradient can be set, and the absolute value of the current output torque of the first motor can be reduced to the target output torque according to this gradient.

[0063] For example, the target output torque can typically be set to zero. By controlling the output torque of the first motor to zero, unnecessary generating torque from the first motor can be avoided, reducing energy loss and improving the overall vehicle transmission efficiency. At the same time, it can also avoid additional torque coupling interference within the planetary gear set, ensuring smooth power output to the wheel ends in mechanical direct drive mode and guaranteeing the smoothness of vehicle operation.

[0064] It is understandable that during the process of controlling the current output torque of the first motor to converge to zero, due to the influence of sensor error, transmission friction and control deviation, the output torque of the first motor is difficult to be absolutely equal to zero. Usually, it can only be controlled to converge the output torque of the first motor to a very small range near zero (e.g., (-0.5, 0.5)).

[0065] For example, the target torque reduction gradient can be set to a fixed value according to actual needs, such as 0.05 Nm / ms.

[0066] The aforementioned target torque reduction gradient can also be dynamically determined based on the vehicle's current operating parameters. For example, the target torque reduction gradient can be dynamically determined based on the torque difference between the current output torque of the first motor and the target output torque, as well as the current output torque of the engine.

[0067] In some embodiments, the target torque reduction gradient is determined by: obtaining the torque difference between the current output torque of the first motor and the target output torque, and obtaining the current output torque of the engine; determining a first correction coefficient based on the absolute value of the torque difference, and determining a second correction coefficient based on the current output torque of the engine; and correcting the basic torque reduction gradient based on the first correction coefficient and the second correction coefficient to obtain the target torque reduction gradient.

[0068] Specifically, a first mapping relationship can be established in advance between the absolute value of the torque difference and a first correction coefficient, and a second mapping relationship can be established between the engine's output torque and a second correction coefficient. After obtaining the torque difference between the current output torque and the target output torque, the first correction coefficient corresponding to the absolute value of the torque difference can be queried in the first mapping relationship; after obtaining the engine's current output torque, the second correction coefficient corresponding to the engine's current output torque can be queried in the second mapping relationship.

[0069] For example, the first mapping relationship between the absolute value of the torque difference and the first correction coefficient can specifically be the mapping relationship between the torque range in which the absolute value of the torque difference is located and the first correction coefficient. That is, first determine the torque difference range in which the absolute value of the torque difference is located, and then query the corresponding first correction coefficient in the first mapping relationship based on the torque difference range in which the absolute value of the torque difference is located.

[0070] For example, the first mapping relationship mentioned above can be shown in Table 1 below: Table 1

[0071] In Table 1 above, △T refers to the absolute value of the torque difference between the current output torque and the target output torque of the first motor; the range of the first correction coefficient is (0,1).

[0072] It is understood that Table 1 above is only an example of the first mapping relationship, and the first mapping relationship may also include the correspondence between other torque ranges and the first correction coefficient.

[0073] As shown in Table 1, the first correction coefficient increases with the increase of the absolute value of the torque difference. The larger the absolute value of the torque difference, the more significant the deviation between the current output torque of the first motor and the target output torque. Using a larger first correction coefficient can increase the torque reduction gradient, thereby accelerating the reduction speed of the absolute value of torque. Conversely, when the absolute value of the torque difference is small, matching a smaller first correction coefficient can reduce the torque reduction gradient, thereby slowing down the reduction speed of the absolute value of torque, avoiding excessive torque adjustment that could cause shock to the transmission system, and balancing adjustment speed and transmission smoothness.

[0074] For example, assuming the current output torque of the first motor is -25 Nm and the target output torque of the first motor is 0, the absolute value of the torque difference between the current output torque and the target output torque of the first motor can be calculated to be 25 Nm. The absolute value of this torque difference is within the torque range of (10, 30). Based on Table 1 above, the first correction coefficient corresponding to the absolute value of this torque difference can be determined to be 0.5.

[0075] Similarly, the second mapping relationship between the engine's output torque and the second correction coefficient can specifically be the mapping relationship between the torque range of the engine's output torque and the second correction coefficient. That is, first determine the output torque range of the engine's current output torque, and then look up the corresponding second correction coefficient in the second mapping relationship based on the output torque range of the engine's current output torque.

[0076] For example, the second mapping relationship described above can be shown in Table 2 below: Table 2

[0077] In Table 2 above, This refers to the current output torque of the engine; the value range of the second correction coefficient mentioned above is (0,1).

[0078] It is understood that Table 2 above is only an example of the second mapping relationship, and the second mapping relationship may also include the correspondence between other torque ranges and the second correction coefficient.

[0079] As shown in Table 2, the second correction coefficient tends to increase as the engine's current output torque increases. When the engine is under low load, the transmission system is more sensitive to sudden torque changes. A smaller second correction coefficient can reduce the torque reduction gradient, thereby slowing down the rate of torque reduction and effectively suppressing transmission system vibration, gear meshing impact, and wheel-end torque fluctuations. As the engine output torque and load increase, the transmission system experiences greater overall force and has stronger resistance to torque disturbances. At this time, a faster torque reduction rate is allowed. Therefore, the second correction coefficient can be increased simultaneously to accelerate the rate of torque reduction, balancing adjustment speed and transmission smoothness.

[0080] For example, assuming the current output torque of the engine is 200 Nm, and it is determined that the current output torque is within the torque range of (160, 250), based on Table 2 above, the second correction factor corresponding to the current output torque of the engine can be determined to be 0.8.

[0081] Furthermore, after determining the first correction coefficient and the second correction coefficient, the basic torque reduction gradient can be corrected based on the first correction coefficient and the second correction coefficient to obtain the target torque reduction gradient.

[0082] The aforementioned basic torque reduction gradient can be a fixed value preset according to actual needs, such as 0.08 Nm / ms.

[0083] For example, the above-mentioned correction of the basic torsion reduction gradient based on the first correction coefficient and the second correction coefficient can be achieved by multiplying the first correction coefficient, the second correction coefficient and the basic torsion reduction gradient to obtain the target torsion reduction gradient.

[0084] For example, assuming the first correction factor is 0.5, the second correction factor is 0.8, and the base torsion reduction gradient is 0.08 Nm / ms, multiplying the first correction factor, the second correction factor, and the base torsion reduction gradient yields the target torsion reduction gradient as 0.5 * 0.8 * 0.08 = 0.032 Nm / ms.

[0085] The above method matches a first correction coefficient with the torque difference between the current output torque of the first motor and the target output torque, and matches a second correction coefficient with the current output torque of the engine. This allows for a dual correction of the basic torque reduction gradient based on the first and second correction coefficients. This method fully considers both the torque difference and the engine load when determining the target torque reduction gradient. It is equivalent to adaptively adjusting the rate of decrease of the absolute value of the output torque of the first motor according to the torque difference and the current output torque of the engine. This significantly improves the smoothness of the transmission system during torque reduction while ensuring the torque adjustment response speed.

[0086] For example, a two-stage torque reduction strategy can also be used to control the absolute value of the current output torque of the first motor to decrease.

[0087] The two-stage torque reduction strategy mentioned above can be either a "fast first, slow later" torque reduction strategy or a "slow first, fast later" torque reduction strategy.

[0088] The aforementioned "fast first, slow later" torque reduction strategy refers to using a large torque reduction gradient in the initial stage to quickly reduce the torque deviation, and then switching to a smaller torque reduction gradient to reduce the torque gradually once the deviation has decreased to a certain extent. This avoids the overshoot and system oscillation caused by continuously using a large torque reduction gradient when the deviation is small. The aforementioned "slow first, fast later" torque reduction strategy refers to using a smaller torque reduction gradient in the initial stage to mitigate the impact of sudden torque changes, and then switching to a larger torque reduction gradient after the system operation has stabilized, in order to accelerate the convergence speed of the remaining torque and make the current output torque of the first motor quickly approach the target output torque.

[0089] In some embodiments, the target torque reduction gradient includes a first torque reduction gradient and a second torque reduction gradient, wherein the absolute values ​​of the first torque reduction gradient and the second torque reduction gradient are not equal. Controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient includes: when the absolute value of the real-time torque difference between the current output torque and the target output torque of the first motor is within a first torque range, controlling the absolute value of the current output torque to decrease according to the first torque reduction gradient until the absolute value of the real-time torque difference is within a second torque range; wherein the lower limit of the first torque range is equal to the upper limit of the second torque range; when the absolute value of the real-time torque difference is within the second torque range, controlling the absolute value of the current output torque of the first motor to continue to decrease according to the second torque reduction gradient until the current output torque of the first motor is reduced to the target output torque.

[0090] Specifically, the absolute value of the first torsion reduction gradient being unequal to the absolute value of the second torsion reduction gradient means that the absolute value of the first torsion reduction gradient is greater than the absolute value of the second torsion reduction gradient, or the absolute value of the first torsion reduction gradient is less than the absolute value of the second torsion reduction gradient.

[0091] It is understandable that if the absolute value of the first torque reduction gradient is greater than the absolute value of the second torque reduction gradient, it corresponds to the "fast first, slow later" torque reduction strategy mentioned above; if the absolute value of the first torque reduction gradient is less than the absolute value of the second torque reduction gradient, it corresponds to the "slow first, fast later" torque reduction strategy mentioned above.

[0092] The real-time torque difference between the current output torque and the target output torque of the first motor refers to the torque difference between the current output torque and the target output torque of the first motor, calculated in real time during the process of controlling the absolute value of the current output torque of the first motor to decrease according to the target torque reduction gradient.

[0093] Furthermore, before controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient, the initial torque difference between the current output torque of the first motor and the target output torque can be calculated first, and the first torque range and the second torque range can be divided according to the absolute value of the initial torque difference. Then, the first torque reduction gradient corresponding to the first torque range and the second torque reduction gradient corresponding to the second torque range can be determined.

[0094] In some embodiments, before controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient, the method further includes: calculating an initial torque difference between the current output torque of the first motor and the target output torque; multiplying the absolute value of the initial torque difference by a preset ratio to obtain a torque threshold; determining the torque range in which the absolute value of the torque difference between the current output torque of the first motor and the target output torque is greater than the torque threshold as a first torque range, and determining the torque range in which the absolute value of the torque difference between the current output torque of the first motor and the target output torque is less than or equal to the threshold as a second torque range.

[0095] The preset ratio can be set according to actual needs, for example, it can be set to 30%.

[0096] For example, assuming the preset ratio is set to 30%, and the absolute value of the initial torque difference between the current output torque and the target output torque of the first motor is 100 Nm, 100 * 30% = 30 Nm can be taken as the dividing threshold between the first torque range and the second torque range. Specifically, the range (30, +∞) where the absolute value of the current torque difference between the current output torque and the target output torque of the first motor is greater than 30 Nm is determined as the first torque range, and the range [0, 30] where the absolute value is less than or equal to 30 Nm is determined as the second torque range.

[0097] Furthermore, the first and second torque reduction gradients mentioned above can be fixed values ​​set according to actual needs.

[0098] For example, suppose the target torque reduction gradient includes two fixed gradient values: 0.05 Nm / ms and 0.08 Nm / ms. If the torque reduction strategy is a "fast first, slow later" torque reduction strategy, then 0.08 Nm / ms is determined as the first torque reduction gradient, and 0.05 Nm / ms is determined as the second torque reduction gradient. If the torque reduction strategy is a "slow first, fast later" torque reduction strategy, then 0.05 Nm / ms is determined as the first torque reduction gradient, and 0.08 Nm / ms is determined as the second torque reduction gradient.

[0099] For example, suppose the target torque reduction gradient includes two fixed gradient values: 0.05 Nm / ms and 0.08 Nm / ms. Suppose the determined first torque range is (30, +∞) and the determined second torque range is [0, 30]. The currently selected torque reduction strategy is a "fast first, slow later" torque reduction strategy. If the calculated real-time torque difference between the current output torque of the first motor and the target output torque is 100 Nm, and this real-time torque difference is determined to be within the first torque range, the first torque gradient corresponding to the first torque range can be determined to be 0.08 Nm / ms. Then, the absolute value of the current output torque of the first motor is controlled to decrease according to this first torque reduction gradient of 0.08 Nm / ms.

[0100] As the absolute value of the current output torque of the first motor continues to decrease, the real-time torque difference between the reduced output torque and the target output torque is updated in real time. When the updated real-time torque difference drops to 30 Nm, it is determined that the real-time torque difference is within the second torque range. Then, the second torque reduction gradient corresponding to the second torque range is determined to be 0.05 Nm / ms. The absolute value of the current output torque of the first motor is then controlled to continue to decrease according to the second torque reduction gradient of 0.05 Nm / ms until the current output torque of the first motor is reduced to the target output torque.

[0101] Optionally, the determination methods for the first and second torque reduction gradients can also refer to the determination method for the target torque reduction gradient described above. Specifically, for the real-time torque difference within the first torque range, a first correction coefficient is determined based on the absolute value of the torque difference, and a second correction coefficient is determined in conjunction with the current engine output torque. The basic torque reduction gradient is then corrected based on the first and second correction coefficients to obtain the first torque reduction gradient. For the real-time torque difference within the second torque range, a first correction coefficient is determined based on the absolute value of the torque difference, and a second correction coefficient is determined in conjunction with the current engine output torque. The basic torque reduction gradient is then corrected based on the first and second correction coefficients to obtain the second torque reduction gradient.

[0102] Understandably, in the "fast first, slow later" torque reduction strategy, the first correction coefficient increases with the absolute value of the torque difference, resulting in a larger torque reduction gradient and faster torque drop during large deviations, and a smaller torque reduction gradient and smoother adjustment during small deviations. In contrast, in the "slow first, fast later" torque reduction strategy, the trend of the first correction coefficient changing with the absolute value of the torque difference can be adjusted accordingly, setting it to decrease as the absolute value of the torque difference increases. This results in a smaller torque reduction gradient during large deviations to suppress torque shocks, and a larger torque reduction gradient during small deviations to accelerate the convergence of residual deviations. The basic calculation architecture for reducing the torque gradient remains unchanged for both strategies; only the relationship between the first correction coefficient and the absolute value of the torque difference is changed.

[0103] For example, under the "fast first, slow later" torque reduction strategy, the first correction coefficient corresponding to the absolute value of the real-time torque difference can be directly determined based on the first mapping relationship shown in Table 1 above. Under the "slow first, fast later" torque reduction strategy, the first mapping relationship shown in Table 1 above can be adjusted so that the trend of the first correction coefficient changing with the absolute value of the torque difference is modified to: the first correction coefficient decreases as the absolute value of the torque difference increases, thus obtaining the adjusted first mapping relationship. Then, the first correction coefficient corresponding to the absolute value of the real-time torque difference can be determined based on the adjusted first mapping relationship.

[0104] Furthermore, after determining the first torque range and the second torque range, during the process of controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient, the torque difference between the current output torque of the first motor and the target output torque can be calculated in real time, and the torque range to which the torque difference belongs can be determined in real time; combined with the currently selected torque reduction strategy, the torque reduction gradient corresponding to the torque range is matched, and the absolute value of the current output torque of the first motor is controlled to continuously decrease according to the matched torque reduction gradient until the current output torque of the first motor converges to the target output torque.

[0105] For example, assuming the determined first torque range is (30, +∞) and the determined second torque range is [0, 30], and the currently selected torque reduction strategy is a "fast first, slow later" torque reduction strategy; if the calculated real-time torque difference between the current output torque of the first motor and the target output torque is 100 Nm, and it is determined that the real-time torque difference is within the first torque range, the first correction coefficient can be matched by looking up the table based on the real-time torque difference of 100 Nm (the first correction coefficient in the table increases with the absolute value of the torque difference), and the second correction coefficient can be matched in combination with the current output torque of the engine to solve the basic torque reduction gradient correction to obtain the first torque reduction gradient, and then the absolute value of the current output torque of the first motor is controlled to decrease according to the first torque reduction gradient.

[0106] As the absolute value of the current output torque of the first motor continues to decrease, the real-time torque difference between the reduced output torque and the target output torque is updated in real time. When the updated real-time torque difference drops to 30 Nm, it is determined that the real-time torque difference is within the second torque range. Then, based on the real-time torque difference of 30 Nm, the first correction coefficient can be matched by looking up a table (the first correction coefficient in the table increases with the increase of the absolute value of the torque difference). Combined with the current output torque of the engine, the second correction coefficient is matched, and the basic torque reduction gradient is corrected and solved to obtain the second torque reduction gradient. Then, the absolute value of the current output torque of the first motor is controlled to continue to decrease according to the second torque reduction gradient until the current output torque of the first motor is reduced to the target output torque.

[0107] The above method divides two interconnected torque ranges and matches a first torque reduction gradient and a second torque reduction gradient with unequal absolute values ​​to the two torque ranges respectively. Then, when the absolute value of the real-time torque difference between the current output torque and the target output torque of the first motor is in different torque ranges, the output torque of the first motor is controlled to decrease in segments according to different torque reduction gradients. By configuring the relative magnitude of the two torque reduction gradients, it can flexibly adapt to two torque reduction strategies: fast first and then slow, or slow first and then fast, thereby improving the flexibility and adaptability of the torque adjustment process.

[0108] In step 203, due to the torque coupling relationship in the planetary gear mechanism, when the output torque of the first motor changes, it will directly act on the end of the gear ring through the torque transmission relationship of the planetary gears and planetary carrier. As the current output torque of the first motor continues to decrease, the torque of the gear ring will also continue to decrease, thereby directly affecting the output torque of the entire vehicle and generating torque disturbance. Based on this, the embodiment of this application can simultaneously control the output of the second motor to output the corresponding target compensation torque while controlling the absolute value of the current output torque of the first motor to decrease, thereby suppressing the torque disturbance caused by the decrease in the absolute value of the torque of the first motor.

[0109] In some embodiments, the method further includes: during the process of controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient, determining the torque change of the gear ring based on the torque change of the first motor; and determining the target compensation torque of the second motor based on the torque change of the gear ring.

[0110] The torque change of the first motor is the torque difference between the output torque of the first motor in the current control cycle and the output torque of the first motor in the previous control cycle, which is used to characterize the torque change of the first motor at each moment during the torque reduction process.

[0111] For example, if the output torque of the first motor in the current control cycle is represented by "Tg_new" and the output torque of the first motor in the previous control cycle is represented by "Tg_old", then the change in torque of the first motor is Tg_new - Tg_old.

[0112] Furthermore, the aforementioned control cycle refers to the minimum operating time interval for the controller to periodically complete signal acquisition, torque calculation, and command issuance, which can typically be set to 5ms.

[0113] Specifically, in each control cycle, the torque change of the first motor and the torque change of the gear ring can be iteratively calculated, and the target compensation torque of the second motor can be updated in real time.

[0114] As mentioned above, the torque change of the gear ring can be determined by combining the torque balance relationship of the planetary gear structure and the torque change of the first motor.

[0115] In some embodiments, determining the torque change of the gear ring based on the torque change of the first motor includes: obtaining a preset gear ring ratio; wherein the preset gear ring ratio is the ratio between the number of teeth on the gear ring and the number of teeth on the sun gear; and determining the torque change of the gear ring based on the torque change of the first motor and the preset gear ring ratio.

[0116] Specifically, the above formula (1) can be transformed to obtain the formula for calculating the torque change of the gear ring, as shown in the following formula (3): Formula (3) In the above formula (3), the above This refers to the change in torque of the gear ring; This refers to the output torque of the first motor within the current control cycle; This refers to the output torque of the first motor in the previous control cycle; K refers to the ratio between the number of teeth on the ring gear and the number of teeth on the sun gear, which is a characteristic coefficient of the planetary gear set, i.e., the preset ring gear ratio mentioned above.

[0117] For example, assuming the preset gear ratio is 3, the output torque of the first motor in the current control cycle is -31.75 Nm, and the output torque of the first motor in the previous control cycle is -32 Nm, substituting the output torque of the first motor in the current control cycle, the output torque of the first motor in the previous control cycle, and the preset gear ratio into the above formula (3), the torque change of the gear can be calculated as [-31.75-(-32)]*3=0.75 Nm.

[0118] Furthermore, since the gear ring and the second motor are rigidly connected, their torques are coupled and linked. Any torque fluctuations in the gear ring will be directly reflected in the second motor. Therefore, after calculating the torque change of the gear ring, the target compensation torque required to offset this fluctuation can be calculated by combining the torque transmission relationship between the two motors. The second motor can then be controlled to output this target compensation torque to suppress torque disturbances caused by torque reduction in the first motor, thus ensuring the stability of the vehicle's wheel-end torque.

[0119] In some embodiments, determining the target compensation torque of the second motor based on the torque change of the gear ring includes: obtaining the transmission ratio of the vehicle's main reducer and the transmission efficiency of the gear ring; multiplying the torque change of the gear ring, the transmission ratio of the main reducer, and the transmission efficiency of the gear ring to obtain the converted torque change; and determining the negative value of the converted torque change as the target compensation torque of the second motor.

[0120] The aforementioned main reducer transmission ratio refers to the ratio of the driven wheel speed to the driving wheel speed of the main reducer, which is used to characterize the torque amplification ratio when power passes through the main reducer; this parameter is an inherent parameter calibrated at the factory of the vehicle reducer and is stored inside the controller. The transmission efficiency of the aforementioned gear ring refers to the ratio between the actual output torque and the input torque during the torque transmission process of the planetary gear ring. It is used to characterize the degree of power transmission loss during the gear ring meshing transmission process and is usually expressed as a percentage. This parameter is usually calibrated through powertrain bench testing and stored as a fixed parameter inside the controller.

[0121] Understandably, the torque fluctuations generated by the gear ring do not act directly on the wheels. This disturbance torque needs to pass through two stages of transmission mechanism—the planetary gear set and the final drive—before it reaches the wheels. In the power transmission path, the transmission efficiency of the gear ring itself and the fixed reduction and torque amplification characteristics of the final drive will cause a fixed proportional change in the amplitude of the input torque.

[0122] Based on this, when calculating the target compensation torque of the second motor, the torque change of the gear ring can be multiplied by the transmission efficiency of the gear ring to correct the torque change of the gear ring, thus obtaining the effective disturbance torque after removing transmission losses. Then, the corrected effective disturbance torque is multiplied by the transmission ratio of the main reducer to obtain the actual disturbance torque at the wheel end equivalent to the disturbance torque. Finally, the negative value of the actual disturbance torque is used as the target compensation torque of the second motor, so that the output torque of the second motor can accurately offset the torque disturbance transmitted to the wheel during the torque reduction process of the first motor, avoid the vehicle from jerking and shock, and improve the smoothness of the torque transition process.

[0123] Specifically, the target compensation torque of the second motor can be calculated using the following formula (4): Formula (4) In the above formula (4), This refers to the target compensation torque of the second motor; This refers to the change in torque of the gear ring; This refers to the gear ratio of the main reducer; This refers to the transmission efficiency of the gear ring.

[0124] For example, assuming the calculated torque change of the gear ring is 0.75 Nm, the transmission ratio of the main reducer is 4, and the transmission efficiency of the gear ring is 97%, by substituting the torque change of the gear ring, the transmission ratio of the main reducer, and the transmission efficiency of the gear ring into the above formula (4), the target compensation torque of the second motor can be calculated as -0.75*4*97%=-2.91 Nm.

[0125] Understandably, when the first clutch is engaged, the first motor typically converges from negative torque to zero. The torque of the first motor is actually rising in the positive direction, causing the torque of the gear ring to increase synchronously, generating positive torque disturbance. Therefore, in order to suppress the generated positive torque disturbance, the second motor can output negative compensation torque to counteract the disturbance torque transmitted from the gear ring to the wheel, thereby smoothly suppressing the vehicle's jerking.

[0126] The above method incorporates the transmission efficiency of the gear ring during the calculation of the target compensation torque of the second motor, thereby obtaining the effective disturbance torque after removing transmission losses. Simultaneously, by combining the transmission ratio of the main reducer, the torque disturbance at the gear ring end can be accurately converted into the equivalent actual disturbance torque at the wheel end. This effectively reduces errors in the torque transmission path and improves the calculation accuracy of the target compensation torque. Based on the negative value of the converted actual disturbance torque, the output compensation torque of the second motor is controlled to accurately counteract the disturbance torque transmitted from the gear ring to the wheel, thereby suppressing the torque disturbance caused by the torque drop of the first motor and improving vehicle driving stability.

[0127] Furthermore, at the instant the first clutch is closed, the engine's output torque will quickly connect to the planetary gear set and be directly transmitted to the ring gear, causing a sudden change in the ring gear torque, which in turn generates instantaneous torque disturbance and can easily cause the whole vehicle to jerk.

[0128] Based on this, in some embodiments, during the process of controlling the first clutch to close, the second motor can be controlled in real time to output a matching compensation torque to counteract the torque fluctuation of the gear ring caused by the engine torque input, so as to suppress the instantaneous torque disturbance under this operating condition.

[0129] It is understandable that the compensation torque value output by the second motor during the first clutch closing process can also be calculated based on the above formula (4). The difference is that the torque change of the gear ring during the first clutch closing process is calculated based on the real-time torque change of the engine. Specifically, the above formula (1) can be modified and then substituted into the real-time torque change of the engine to calculate the value.

[0130] In some embodiments, if preset conditions are met, it is determined that the vehicle's operating mode has been smoothly switched to mechanical direct drive mode.

[0131] The aforementioned preset conditions include the absolute value of the current output torque of the first motor being less than or equal to a preset torque threshold and the duration for which the absolute value of the current output torque of the first motor is less than or equal to the preset torque threshold being greater than a preset duration.

[0132] For example, the preset torque threshold and preset duration can be set according to actual needs. For instance, the preset torque threshold can be set to 5 Nm and the preset duration can be set to 100 ms.

[0133] Furthermore, once it is confirmed that the vehicle's operating mode has been smoothly switched to mechanical direct drive mode, the first motor can stop outputting torque or enter standby mode.

[0134] Figure 3 This is a schematic diagram of the structure of a vehicle control device provided in an embodiment of this application.

[0135] For example, the device is applied to a hybrid vehicle, which includes an engine, a first motor, a planetary gear set, a first clutch, a second motor, and a differential. The engine is connected to the first motor via the planetary gear set, the first clutch is connected to the planetary gear set, and the second motor is connected to the differential. like Figure 3 As shown, the device 300 includes: The determination module 301 is used to determine the current output torque of the first motor based on the current output torque of the engine when the first clutch is in the closed state.

[0136] The first control module 302 is used to control the absolute value of the current output torque of the first motor to be reduced to the target output torque according to the target torque reduction gradient.

[0137] The second control module 303 is used to control the second motor to output a corresponding target compensation torque during the process of controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient, so as to suppress the torque disturbance caused by the decrease in the absolute value of the torque of the first motor.

[0138] In some embodiments, the planetary gear set includes a sun gear, a planet carrier, and a ring gear. The sun gear is connected to a first motor, the planet carrier is connected to an engine, and the ring gear is connected to the vehicle's power output shaft. The determining module is specifically used to: obtain a preset ring gear ratio; wherein the preset ring gear ratio is the ratio between the number of teeth on the ring gear and the number of teeth on the sun gear; and determine the current output torque of the first motor based on the current output torque of the engine and the preset ring gear ratio.

[0139] Optionally, the device further includes a gradient determination module, which is specifically used to: obtain the torque difference between the current output torque of the first motor and the target output torque, and obtain the current output torque of the engine; determine a first correction coefficient based on the absolute value of the torque difference, and determine a second correction coefficient based on the current output torque of the engine; and correct the basic torque reduction gradient based on the first correction coefficient and the second correction coefficient to obtain the target torque reduction gradient.

[0140] In some embodiments, the target torque reduction gradient includes a first torque reduction gradient and a second torque reduction gradient, wherein the absolute values ​​of the first torque reduction gradient and the second torque reduction gradient are not equal. The first control module is specifically configured to: when the absolute value of the real-time torque difference between the current output torque of the first motor and the target output torque is within a first torque range, control the absolute value of the current output torque to decrease according to the first torque reduction gradient until the absolute value of the real-time torque difference is within a second torque range; wherein the lower limit of the first torque range is equal to the upper limit of the second torque range; when the absolute value of the real-time torque difference is within the second torque range, control the absolute value of the current output torque of the first motor to continue to decrease according to the second torque reduction gradient until the current output torque of the first motor is reduced to the target output torque.

[0141] Optionally, the device further includes a torque range determination module, which is specifically used to: calculate the initial torque difference between the current output torque of the first motor and the target output torque; multiply the absolute value of the initial torque difference by a preset ratio to obtain a torque threshold; determine the torque range in which the absolute value of the torque difference between the current output torque of the first motor and the target output torque is greater than the torque threshold as the first torque range, and determine the torque range in which the absolute value of the torque difference between the current output torque of the first motor and the target output torque is less than or equal to the threshold as the second torque range.

[0142] Optionally, the planetary gear set includes a sun gear, a planet carrier, and a ring gear. The sun gear is connected to the first motor, the planet carrier is connected to the engine, and the ring gear is connected to the second motor. The device also includes a second determining module, which is specifically used to: determine the torque change of the ring gear based on the torque change of the first motor during the process of controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient; and determine the target compensation torque of the second motor based on the torque change of the ring gear.

[0143] In some embodiments, the second determining module includes a first determining unit, which is specifically used to: obtain a preset gear ratio; wherein the preset gear ratio is the ratio between the number of teeth on the gear ring and the number of teeth on the sun gear; and determine the torque change of the gear ring based on the torque change of the first motor and the preset gear ratio.

[0144] In some embodiments, the second determining module includes a second determining unit, which is specifically used to: obtain the transmission ratio of the vehicle's main reducer and the transmission efficiency of the gear ring; multiply the torque change of the gear ring, the transmission ratio of the main reducer, and the transmission efficiency of the gear ring to obtain the converted torque change; and determine the negative value of the converted torque change as the target compensation torque of the second motor.

[0145] Figure 4 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application.

[0146] For example, such as Figure 4 As shown, the vehicle 400 includes a memory 401 and a processor 402. The memory 401 stores executable program code 4011, and the processor 402 is used to call and execute the executable program code 4011 to perform a vehicle control method.

[0147] Furthermore, embodiments of this application also protect 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 vehicle control method provided in embodiments of this application.

[0148] 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.

[0149] When each functional module is divided according to its corresponding function, the device may further include a 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.

[0150] It should be understood that the device provided in this embodiment is used to execute the above-described vehicle control method, and therefore can achieve the same effect as the above-described implementation method.

[0151] 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 and data.

[0152] 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.

[0153] 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 vehicle control method provided in the above embodiments.

[0154] 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 above-described related method steps to implement a vehicle control method provided in the above embodiment.

[0155] 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 vehicle control method provided in the above embodiment.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] 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 controlling a vehicle, characterized in that, The method is applied to a hybrid vehicle, the vehicle comprising: an engine, a first motor, a planetary gear set, a first clutch, a second motor, and a differential, wherein the engine is connected to the first motor via the planetary gear set, the first clutch is connected to the planetary gear set, and the second motor is connected to the differential; The method includes: With the first clutch engaged, the current output torque of the first motor is determined based on the current output torque of the engine. The absolute value of the current output torque of the first motor is controlled to be reduced to the target output torque according to the target torque reduction gradient; During the process of controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient, the second motor is controlled to output the corresponding target compensation torque to suppress the torque disturbance caused by the decrease in the absolute value of the torque of the first motor.

2. The method according to claim 1, characterized in that, The planetary gear set includes a sun gear, a planet carrier, and a ring gear. The sun gear is connected to the first motor, the planet carrier is connected to the engine, and the ring gear is connected to the vehicle's power output shaft. Determining the current output torque of the first motor based on the current output torque of the engine includes: Obtain a preset gear ratio; wherein the preset gear ratio is the ratio between the number of teeth on the gear ring and the number of teeth on the sun gear; The current output torque of the first motor is determined based on the current output torque of the engine and the preset gear ratio.

3. The method according to claim 1, characterized in that, The target torsion reduction gradient is determined in the following way: Obtain the torque difference between the current output torque and the target output torque of the first motor, and obtain the current output torque of the engine; A first correction factor is determined based on the absolute value of the torque difference, and a second correction factor is determined based on the current output torque of the engine. Based on the first correction coefficient and the second correction coefficient, the basic torsion reduction gradient is corrected to obtain the target torsion reduction gradient.

4. The method according to claim 1 or 3, characterized in that, The target torque reduction gradient includes a first torque reduction gradient and a second torque reduction gradient, wherein the absolute values ​​of the first torque reduction gradient and the second torque reduction gradient are not equal. Controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient includes: When the absolute value of the real-time torque difference between the current output torque and the target output torque of the first motor is within the first torque range, the absolute value of the current output torque is controlled to decrease according to the first torque reduction gradient until the absolute value of the real-time torque difference is within the second torque range; wherein, the lower limit of the first torque range is equal to the upper limit of the second torque range; When the absolute value of the real-time torque difference is within the second torque range, the absolute value of the current output torque of the first motor is controlled to continue to decrease according to the second torque reduction gradient until the current output torque of the first motor is reduced to the target output torque.

5. The method according to claim 4, characterized in that, Before the absolute value of the current output torque of the first motor is reduced to the target output torque according to the target torque reduction gradient, the method further includes: Calculate the initial torque difference between the current output torque of the first motor and the target output torque; The absolute value of the initial torque difference is multiplied by a preset ratio to obtain the torque threshold. The torque range in which the absolute value of the torque difference between the current output torque of the first motor and the target output torque is greater than the torque threshold is defined as the first torque range, and the torque range in which the absolute value of the torque difference between the current output torque of the first motor and the target output torque is less than or equal to the threshold is defined as the second torque range.

6. The method according to claim 1, characterized in that, The planetary gear set includes a sun gear, a planet carrier, and a ring gear. The sun gear is connected to the first motor, the planet carrier is connected to the engine, and the ring gear is connected to the second motor. The method further includes: During the process of controlling the absolute value of the current output torque of the first motor to decrease to the target output torque according to the target torque reduction gradient, the torque change of the gear ring is determined based on the torque change of the first motor. The target compensation torque of the second motor is determined based on the torque change of the gear ring.

7. The method according to claim 6, characterized in that, Determining the torque change of the gear ring based on the torque change of the first motor includes: Obtain a preset gear ratio; wherein the preset gear ratio is the ratio between the number of teeth on the gear ring and the number of teeth on the sun gear; The torque change of the gear ring is determined based on the torque change of the first motor and the preset gear ring ratio.

8. The method according to claim 6, characterized in that, Determining the target compensation torque of the second motor based on the torque change of the gear ring includes: Obtain the transmission ratio of the main reducer of the vehicle and the transmission efficiency of the gear ring; The torque change of the gear ring, the transmission ratio of the main reducer, and the transmission efficiency of the gear ring are multiplied to obtain the converted torque change. The negative value of the converted torque change is determined as the target compensation torque of the second motor.

9. 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 8.

10. 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 8.

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