Vehicle control method, device, vehicle and storage medium

Abstract

The present application provides a method, device, vehicle and storage medium for vehicle control, which is applied to the field of vehicles, and includes: when the vehicle is currently in an idle pure electric four-wheel drive mode, judging whether the switching condition for switching from the idle pure electric four-wheel drive mode to the series mode is met; if the switching condition is met, then during the mode switching process, an idle request signal carrying a first signal value is continuously sent to the engine controller; wherein, in the idle pure electric four-wheel drive mode, the front drive motor and the rear drive motor of the vehicle are in a driving state, the engine is in an idle state, and the clutch is in a disengaged state; the first signal value is used to instruct the engine controller to activate the idle state of the engine. This method can avoid the phenomenon of the engine speed fluctuating in the process of switching from the idle pure electric four-wheel drive mode to the series mode, which is conducive to improving the driver's driving experience.

Description

Technical Field

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

[0002] With the advancement of science and technology and the development of automotive electronics, hybrid vehicles are usually equipped with conventional operating modes including direct drive mode, pure electric four-wheel drive mode and series mode to adapt to different road conditions and driving requirements.

[0003] Although some hybrid vehicles are currently equipped with a special operating mode such as pure electric four-wheel drive mode, in the related art, when the vehicle switches from the idle pure electric four-wheel drive mode to the series mode, the engine speed fluctuates and the noise is obvious, which affects the driver's experience. Summary of the invention

[0004] The present application provides a vehicle control method, device, vehicle and storage medium. The method can avoid the phenomenon of engine speed fluctuating during the process of switching from idle pure electric four-wheel drive mode to series mode, which is conducive to improving the driver's driving experience.

[0005] In a first aspect, a vehicle control method is provided, the method comprising: when the vehicle is currently in an idle pure electric four-wheel drive mode, determining whether a switching condition for switching from the idle pure electric four-wheel drive mode to a series mode is met; if the switching condition is met, maintaining an idle request signal carrying a first signal value to be sent to an engine controller during the mode switching process; wherein, in the idle pure electric four-wheel drive mode, the front drive motor and rear drive motor of the vehicle are in a driving state, the engine is in an idle state, and the clutch is in a disengaged state; in the series mode, the rear drive motor is in a driving state, the engine runs to drive the front drive motor to generate electricity, and the clutch is in a closed state; the first signal value is used to instruct the engine controller to activate the idle state of the engine.

[0006] In the above technical solution, when the vehicle is currently in the idle pure electric four-wheel drive mode, if the mode switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met, it means that the current target operation mode is the series mode. At this time, although the target operation mode is the series mode, it will not follow the conventional control method, that is, the VCU will send an idle request signal indicating that the idle is not activated to the engine controller to request the engine to exit the idle state, but the VCU will continue to send an idle request signal carrying the first signal value to the engine controller during the mode switching process to request the engine to continue to activate the idle state, so that the vehicle maintains the same control method as the idle pure electric four-wheel drive mode during the process of switching from the idle pure electric four-wheel drive mode to the series mode, avoiding the change of torque control authority from the engine controller ECM to the vehicle controller VCU, that is, during the process of switching from the idle pure electric four-wheel drive mode to the series mode, the engine's torque control authority is still ECM, which is conducive to avoiding the phenomenon of the engine speed fluctuating, thereby improving the driver experience during the mode switching process.

[0007] In combination with the first aspect, in some possible implementations, the series mode is a first type of series mode or a second type of series mode. In the first type of series mode, the engine is in an idle state, and in the second type of series mode, the engine is in a non-idle state; after maintaining sending an idle request signal carrying a first signal value to the engine controller during the mode switching process, the method also includes: if it is detected that the vehicle has switched from the idle pure electric four-wheel drive mode to the first type of series mode, continuing to send an idle request signal carrying the first signal value to the engine controller; if it is detected that the vehicle has switched from the idle pure electric four-wheel drive mode to the second type of series mode, sending an idle request signal carrying a second signal value to the engine controller; wherein the second signal value is used to indicate that the engine controller does not activate the idle state of the engine.

[0008] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, when the vehicle has switched from the idle pure electric four-wheel drive mode to the first type of series mode, the target idle speed is sent to the engine controller so that the engine controller controls the idle speed of the engine according to the target idle speed; when the vehicle has switched from the idle pure electric four-wheel drive mode to the second type of series mode, the engine is requested to output a pre-calibrated power generation torque corresponding to the current vehicle condition data.

[0009] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the judgment of whether the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met includes: obtaining the current remaining power, current gear, current energy mode and driving mode of the vehicle; if the remaining power of the vehicle is less than the preset power threshold, it is determined that the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met; if the combination of the current energy mode and driving mode meets the preset combination conditions, and the current gear is P gear, it is determined that the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met; wherein, the preset combination conditions include: the current energy mode is pure electric priority mode or hybrid mode, and the driving mode is AWD mode, snow mode, mud mode or sand mode.

[0010] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, when the vehicle is detected to be started, an idle request signal, an idle speed signal and an idle load torque signal are sent to an engine controller, so that the engine controller activates the idle state of the engine based on a first signal value carried in the idle request signal, or does not activate the idle state of the engine based on a second signal value carried in the idle request signal, and instructs the engine controller to control the idle speed of the engine based on the target idle speed carried in the idle speed signal when the idle state of the engine is activated, and to control the idle torque of the engine based on the target idle torque carried in the idle load torque signal.

[0011] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the first signal value or the second signal value carried in the idle request signal is determined in the following manner: when the preset idle activation condition is met, it is determined that the idle request signal carries the first signal value; when the preset idle activation condition is not met, it is determined that the idle request signal carries the second signal value; wherein the idle activation condition includes: a first preset condition, a second preset condition or a third preset condition; the first preset condition includes: the target operating mode of the vehicle is the idle pure electric four-wheel drive mode; the second preset condition includes: the actual operating mode of the vehicle is the idle pure electric four-wheel drive mode, the target operating mode is the series mode and the clutch is in a disengaged state; the third preset condition includes: the battery pack temperature of the vehicle is lower than the first temperature threshold, or the coolant temperature of the engine is lower than the second temperature threshold.

[0012] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, if the following conditions are met, the target operation mode is determined to be the idle pure electric four-wheel drive mode: the current remaining power of the vehicle is greater than the preset power threshold; and the current speed of the vehicle is less than or equal to the preset speed threshold; and the current gear of the vehicle is not the P gear; and, when the current energy mode of the vehicle is the pure electric priority mode or the hybrid mode, the driving mode of the vehicle is the AWD mode, the snow mode, the mud mode or the sand mode.

[0013] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the target idle speed carried in the idle speed signal is determined in the following manner: when the actual operating mode of the vehicle is the idle pure electric four-wheel drive mode, the current target operating mode of the vehicle is determined, and based on the current target operating mode, the target idle speed of the engine is determined; when the actual operating mode of the vehicle is not the idle pure electric four-wheel drive mode, the pre-calibrated series idle speed is determined as the target idle speed; wherein, the series idle speed is used to make the engine idle in the series mode to drive the front drive motor to generate electricity.

[0014] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the target idle speed of the engine is determined according to the current target operating mode, including: if the current target operating mode is the series mode, the series idle speed is determined as the target idle speed; if the current target operating mode is the direct drive mode, the engine target speed received from the TCU is determined as the target idle speed; wherein the engine target speed sent by the TCU is calculated by the TCU based on the current gear position and the current vehicle speed; if the current target operating mode is the idle pure electric four-wheel drive mode, the engine target speed calculated by the VCU based on the current gear position and the current vehicle speed is determined as the target idle speed.

[0015] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the target idle torque carried in the idle load torque signal is determined in the following manner: if the idle request signal carries the second signal value, the target idle torque is determined to be 0; if the idle request signal carries the first signal value, it is determined whether the current target operation mode of the vehicle is the idle pure electric four-wheel drive mode and whether the clutch is in a disengaged state; if so, the target idle torque is determined to be 0; if not, the target idle torque is determined to be a pre-calibrated power generation torque corresponding to the current vehicle condition data.

[0016] In a second aspect, a vehicle control device is provided, which includes: a judgment module, used to judge whether the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met when the vehicle is currently in the idle pure electric four-wheel drive mode; a sending module, used to keep sending an idle request signal carrying a first signal value to the engine controller during the mode switching process if the switching conditions are met; wherein, in the idle pure electric four-wheel drive mode, the front drive motor and the rear drive motor of the vehicle are in a driving state, the engine is in an idle state, and the clutch is in a disengaged state; in the series mode, the rear drive motor is in a driving state, the engine runs to drive the front drive motor to generate electricity, and the clutch is in a closed state; the first signal value is used to instruct the engine controller to activate the idle state of the engine.

[0017] In combination with the second aspect, in some possible implementations, the series mode is a first type of series mode or a second type of series mode. In the first type of series mode, the engine is in an idle state, and in the second type of series mode, the engine is in a non-idle state; the sending module is also used for: if it is detected that the vehicle has switched from the idle pure electric four-wheel drive mode to the first type of series mode, then continue to send an idle request signal carrying the first signal value to the engine controller; if it is detected that the vehicle has switched from the idle pure electric four-wheel drive mode to the second type of series mode, then send an idle request signal carrying a second signal value to the engine controller; wherein the second signal value is used to instruct the engine controller not to activate the idle state of the engine.

[0018] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the sending module is also used to: when the vehicle has switched from the idle pure electric four-wheel drive mode to the first type of series mode, send the target idle speed to the engine controller, so that the engine controller controls the idle speed of the engine according to the target idle speed; when the vehicle has switched from the idle pure electric four-wheel drive mode to the second type of series mode, request the engine to output a pre-calibrated power generation torque corresponding to the current vehicle condition data.

[0019] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the judgment module is specifically used to: obtain the current remaining power, current gear, current energy mode and driving mode of the vehicle; if the remaining power of the vehicle is less than the preset power threshold, it is determined that the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met; if the combination of the current energy mode and driving mode meets the preset combination conditions, and the current gear is P gear, it is determined that the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met; wherein, the preset combination conditions include: the current energy mode is pure electric priority mode or hybrid mode, and the driving mode is AWD mode, snow mode, mud mode or sand mode.

[0020] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the sending module is also used to: when detecting that the vehicle is started, send an idle request signal, an idle speed signal and an idle load torque signal to the engine controller, so that the engine controller activates the idle state of the engine based on a first signal value carried in the idle request signal, or does not activate the idle state of the engine based on a second signal value carried in the idle request signal, and instructs the engine controller to control the idle speed of the engine based on the target idle speed carried in the idle speed signal when activating the idle state of the engine, and to control the idle torque of the engine based on the target idle torque carried in the idle load torque signal.

[0021] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the above-mentioned device also includes: a signal value determination module, which is used to determine that the idle request signal carries the first signal value when the preset idle activation condition is met; when the preset idle activation condition is not met, determine that the idle request signal carries the second signal value; wherein the idle activation condition includes: a first preset condition, a second preset condition or a third preset condition; the first preset condition includes: the target operating mode is the idle pure electric four-wheel drive mode; the second preset condition includes: the actual operating mode is the idle pure electric four-wheel drive mode, the target operating mode is the series mode and the clutch is in a disengaged state; the third preset condition includes: the battery pack temperature of the vehicle is lower than the first temperature threshold, or the coolant temperature of the engine is lower than the second temperature threshold.

[0022] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the above-mentioned device also includes: a determination module, which is used to determine that the target operation mode is the idle pure electric four-wheel drive mode if the following conditions are met: the current remaining power of the vehicle is greater than the preset power threshold; and the current speed of the vehicle is less than or equal to the preset speed threshold; and the current gear of the vehicle is not P gear; and, when the current energy mode of the vehicle is pure electric priority mode or hybrid mode, the driving mode is AWD mode, snow mode, mud mode or sand mode.

[0023] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the above-mentioned device also includes: a target idle speed determination module, which is used to determine the current target operation mode of the vehicle when the actual operation mode of the vehicle is the idle pure electric four-wheel drive mode, and determine the target idle speed of the engine based on the current target operation mode; when the actual operation mode of the vehicle is not the idle pure electric four-wheel drive mode, the pre-calibrated series idle speed is determined as the target idle speed; wherein, the series idle speed is used to make the engine idle in the series mode to drive the front drive motor to generate electricity.

[0024] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the target idle speed determination module is specifically used to: if the current target operation mode is the series mode, then the series idle speed is determined as the target idle speed; if the current target operation mode is the direct drive mode, then the engine target speed received and sent by the TCU is determined as the target idle speed; wherein, the engine target speed sent by the TCU is calculated by the TCU based on the current gear position and the current vehicle speed; if the current target operation mode is the idle pure electric four-wheel drive mode, then the engine target speed calculated by the VCU based on the current gear position and the current vehicle speed is determined as the target idle speed.

[0025] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the above-mentioned device also includes: a target idle torque determination module, which is used to determine that the target idle torque is 0 if the idle request signal carries the second signal value; if the idle request signal carries the first signal value, it is judged whether the current target operation mode of the vehicle is the idle pure electric four-wheel drive mode and whether the clutch is in a disengaged state; if so, it is determined that the target idle torque is 0; if not, it is determined that the target idle torque is a pre-calibrated power generation torque corresponding to the current vehicle condition data.

[0026] In a third aspect, a vehicle is provided, comprising: a memory for storing executable program code; and a processor for calling and running the executable program code from the memory, so that the vehicle executes the method in the above-mentioned first aspect or any possible implementation of the first aspect.

[0027] In a fourth aspect, a computer program product is provided, comprising: a computer program code, which, when executed on a computer, enables the computer to execute the method in the first aspect or any possible implementation of the first aspect.

[0028] In a fifth aspect, a computer-readable storage medium is provided, which stores a computer program code. When the computer program code runs on a computer, the computer executes the method in the above-mentioned first aspect or any possible implementation manner of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a structural schematic diagram of a hybrid vehicle provided by an embodiment of the present application;

[0030] Figure 2 is a schematic diagram of a pure electric four-wheel drive mode provided in an embodiment of the present application;

[0031] Figure 3 is a schematic diagram of a series connection mode provided in an embodiment of the present application;

[0032] Figure 4 is a schematic diagram of a direct drive mode provided in an embodiment of the present application;

[0033] Figure 5 It is a schematic diagram of an idle pure electric four-wheel drive mode provided in an embodiment of the present application;

[0034] Figure 6 It is a timing diagram for switching from an idle pure electric four-wheel drive mode to a series mode provided in an embodiment of the present application;

[0035] Figure 7 is a schematic flow chart of a vehicle control method provided in an embodiment of the present application;

[0036] Figure 8 is a timing diagram of mode switching involved in the vehicle control method provided in an embodiment of the present application;

[0037] Fig. 9 is a structural schematic diagram of a vehicle control device provided in an embodiment of the present application;

[0038] Fig.10 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0040] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0041] Figure 1 This is a schematic diagram of the structure of a hybrid vehicle. Figure 1 As shown, the vehicle 100 includes: a front drive motor 101, a rear drive motor 102, an engine 103, a clutch 104, a front axle transmission 105, a rear axle transmission 106, a front axle differential 107, a rear axle differential 108, front wheels, rear wheels, and a coupling 111. The front wheels include a left front wheel 1091 and a right front wheel 1092. The rear wheels include a left rear wheel 1101 and a right rear wheel 1102.

[0042] The front drive motor 101 is arranged on the front axle, and is used to provide power to the front wheels through the front drive shaft to drive the vehicle. The front drive motor 101 is connected to the clutch 104 through the coupling 111, the first end of the clutch 104 is connected to the engine 103, and the second end of the clutch 104 is connected to the first end of the front axle transmission 105. The second end of the front axle transmission 105 is connected to the front axle differential 107, and the front axle differential 107 is arranged between the left front wheel 1091 and the right front wheel 1092.

[0043] The rear drive motor 102 is arranged on the rear axle, and is used to provide power to the rear wheels through the rear drive shaft to drive the vehicle. The rear drive motor 102 is connected to a first end of a rear axle transmission 106, and a second end of the rear axle transmission 106 is connected to a rear axle differential 108, and the rear axle differential 108 is arranged between the left rear wheel 1101 and the right rear wheel 1102.

[0044] The hybrid vehicle adopting the above-mentioned architecture is equipped with a front-wheel drive motor 101, a rear-wheel drive motor 102 and an engine 103 at the same time. Therefore, in order to adapt to different road conditions and driving requirements, multiple operating modes are usually provided including a direct drive mode, a pure electric four-wheel drive mode and a series mode.

[0045] Figure 2 This is a schematic diagram of the pure electric four-wheel drive mode. When the vehicle is in pure electric four-wheel drive mode, the engine does not participate in the work, that is, the engine neither drives nor generates electricity. The vehicle's battery pack is used to power the front and rear drive motors. The front drive motor drives the front wheels, and the rear drive motor drives the rear wheels. Figure 1 When the vehicle is in the pure electric four-wheel drive mode, the engine 103 is turned off, the clutch 104 is in a disengaged state, and the front drive motor 101 and the rear drive motor 102 jointly drive the vehicle.

[0046] Figure 3 This is a schematic diagram of the series mode. When the vehicle is in series mode, the engine participates in the work, specifically participating in the generation of electricity for the vehicle. The engine runs to drive the front drive motor to run and generate electricity. The electricity generated by the front drive motor can charge the vehicle's battery pack. The front wheels are in a driven state, and the battery pack supplies power to the rear drive motor. The rear drive motor outputs power, and the rear wheels are driven to drive the vehicle forward. Figure 1 When the vehicle is in series mode, the engine 103 is in working state, the clutch 104 is in a closed state, the engine 103 runs to drive the front drive motor 101 to run and generate electricity, and the electric energy generated by the front drive motor 101 can charge the battery pack of the vehicle.

[0047] Figure 4 This is a schematic diagram of the direct drive mode. When the vehicle is in direct drive mode, the engine is involved in the work, specifically in driving the vehicle. Figure 1 In the direct drive mode, the clutch 104 is closed, and the engine 103, the front drive motor 101 and the rear drive motor 102 jointly drive the vehicle.

[0048] Figure 5 This is a schematic diagram of the idle pure electric four-wheel drive mode. When the vehicle is in the idle pure electric four-wheel drive mode, the engine starts and is in the idle state. The engine is decoupled from the wheels, and the engine has no power output to the wheels. The power is only driven by the front and rear drive motors. Figure 1 In the idling pure electric four-wheel drive mode, the clutch 104 is in a disengaged state, the engine 103 is in an idling state, and the front drive motor 101 and the rear drive motor 102 jointly drive the vehicle.

[0049] The inventor of the present application has found that in the related art, Figure 1 The vehicle shown in the figure switches from idle pure electric four-wheel drive mode to series mode, and the engine speed fluctuates and the noise is obvious. Figure 6 The process of switching from the idle pure electric four-wheel drive mode to the series mode in the related art is explained.

[0050] Figure 6 This is the timing diagram for switching from idle pure electric four-wheel drive mode to series mode.

[0051] For example, Figure 6 As shown, switching from idle pure electric four-wheel drive mode to series mode includes three stages, namely: the first stage (idle pure electric four-wheel drive mode), the second stage (the process of switching from idle pure electric four-wheel drive mode to series mode), and the third stage (series mode). Figure 6 In the diagram, the idle pure electric four-wheel drive mode is abbreviated as Idle EAWD.

[0052] Phase 1: The vehicle is stable in the idling pure electric four-wheel drive mode. Figure 6 As shown in the figure, in the first stage, the actual operation mode and target operation mode of the vehicle are both the idle pure electric four-wheel drive mode, the clutch is in a disengaged state, and the engine torque requested by the vehicle controller (VCU) is the friction torque, which is a negative value. The idle request signal indicates the activation of the idle state, the target idle torque carried in the idle load torque signal is 0, and the actual engine speed follows the target idle speed in the idle speed signal, specifically 1100rpm in the figure.

[0053] The second stage: the process of the vehicle switching from the idle pure electric four-wheel drive mode to the series mode. In the second stage, the target operation mode is the series mode, and the actual operation mode is the idle pure electric four-wheel drive mode. The idle request signal indicates that the idle state is not activated. Therefore, in the second stage, the VCU, the engine control module (Engine Control Module, ECM) and other components will not pay attention to the idle load torque signal and the idle speed signal at this stage. The figure shows that the idle load torque signal and the idle speed signal in the second stage are dotted lines. The second stage can be further subdivided into: torque reduction stage, gear disengagement stage and speed regulation stage.

[0054] In the torque reduction phase, the torque reduction here specifically refers to reducing the front drive motor torque requested by the VCU and the engine torque requested by the VCU. Figure 6 As shown in the figure, in the first stage, the vehicle is in the idling pure electric four-wheel drive mode. In the idling pure electric four-wheel drive mode, the engine is in an idling state, neither driving nor generating electricity. The engine torque requested by the VCU is a negative friction torque. Therefore, for the torque reduction stage in the second stage, the torque reduction of the engine actually refers to reducing the absolute value of the engine torque requested by the VCU. Figure 6 It is manifested as follows: in the torque reduction stage, the engine torque requested by the VCU increases from the negative friction torque to close to 0.

[0055] During the gear shifting stage, when the front-drive motor torque requested by the VCU and the engine torque requested by the VCU are reduced to near 0, the transmission control unit (TCU) executes the gear shifting and switches the current gear from 1st gear in the idle pure electric four-wheel drive mode to N gear to meet the gear requirements of the series mode.

[0056] Speed ​​regulation stage: synchronize the front drive motor and engine speed and control the clutch closing. Figure 6 It can be seen that during the speed regulation stage, the actual engine speed and the engine torque requested by the VCU fluctuate.

[0057] Stage 3: The vehicle is stable in series mode. Figure 6 As shown, in the third stage, the target operation mode and the actual operation mode are both series mode, and the clutch is in a closed state.

[0058] pass Figure 6 It can be seen that when the target operation mode is changed from the idle pure electric four-wheel drive mode to the series mode, the idle request signal sent by the VCU to the engine controller ECM changes from indicating the activation of the idle to indicating the deactivation of the idle, so that the state of the engine changes from the idle state to the non-idle state. When the VCU requests the engine's idle state to be activated, the vehicle's power control mode is engine-controlled idle. When the VCU requests the engine's idle state to be deactivated, the vehicle's power control mode is VCU-controlled engine torque.

[0059] The above engine idle speed control means that the ECM controls the actual engine speed according to the target idle speed sent by the VCU. Specifically, when the ECM determines that the actual engine speed is greater than the target idle speed, it controls the engine to reduce the output torque, and vice versa, it controls the engine to increase the output torque so that the actual engine speed follows the target idle speed. In other words, the torque control right of the engine idle speed control method lies in the engine controller ECM.

[0060] The above VCU-controlled engine torque means that the VCU determines the target engine speed by itself, and adjusts the engine request torque through proportional integral (PI) according to the speed difference between the target engine speed and the actual engine speed, so that the actual engine speed reaches the target engine speed. In other words, the torque control right of the VCU-controlled engine torque control method lies in the vehicle controller VCU.

[0061] When the idle request signal sent by the VCU to the ECM changes from indicating idle activation to indicating idle deactivation, it is equivalent to interrupting the control mode of engine idle control and changing to VCU controlling engine torque control mode. Figure 6During the torque reduction and gear shifting phase, the engine torque requested by the VCU is close to or equal to 0, and the engine speed will drop without torque control (e.g. Figure 6 The actual engine speed continues to decrease during the torque reduction and gear shifting phases), and then enters the VCU to control the engine torque. The VCU uses the speed difference between the actual engine speed and the target engine speed, and the PI adjusts the engine torque requested by the VCU. However, due to the power lag of the internal combustion engine, the engine torque requested by the VCU will fluctuate, and the actual engine speed will also fluctuate up and down (such as Figure 6 The actual engine speed in the middle speed regulation stage fluctuates up and down), which is not easy to adjust stably and the noise is obvious.

[0062] Based on this, in order to solve the technical problem that the engine speed fluctuates and the noise is obvious during the process of switching from the idle pure electric four-wheel drive mode to the series mode, the inventor of the present application found that the essential reason for the above technical problem is: in the process of switching from the idle pure electric four-wheel drive mode to the series mode, that is, the above second stage (torque reduction, gear removal, speed regulation stage), the VCU requests the engine's idle state to be inactivated, resulting in a change in the torque control right, and the torque control right is changed from the engine controller ECM to the vehicle controller VCU. Therefore, the embodiment of the present application proposes a technical solution to the above technical problem from the perspective of avoiding the change of the torque control right during the mode switching process. The control method of the vehicle provided in the embodiment of the present application is applied to the vehicle controller VCU. In the control method, in the process of switching from the idle pure electric four-wheel drive mode to the series mode, the VCU continues to send an idle request signal indicating the activation of the engine idle state, so that the process continues to maintain the engine idle control control mode, avoiding the change of the torque control right, so that the engine speed will not fluctuate during the process of switching from the idle pure electric four-wheel drive mode to the series mode, which is conducive to improving the driver experience during the mode switching process.

[0063] Figure 7 It is a schematic flow chart of a vehicle control method provided in an embodiment of the present application.

[0064] For example, Figure 7 As shown, the control method includes:

[0065] Step 701: When the vehicle is currently in an idling pure electric four-wheel drive mode, determine whether the switching conditions for switching from the idling pure electric four-wheel drive mode to the series mode are met.

[0066] Step 702: If the switching condition is met, the idle request signal carrying the first signal value is continuously sent to the engine controller during the mode switching process. In the idle pure electric four-wheel drive mode, the front drive motor and the rear drive motor of the vehicle are in the driving state, the engine is in the idle state, and the clutch is in the disengaged state. In the series mode, the rear drive motor is in the driving state, the engine runs to drive the front drive motor to generate electricity, and the clutch is in the closed state; the first signal value is used to instruct the engine controller ECM to activate the idle state of the engine.

[0067] exist Figure 7 In the embodiment shown, when the vehicle is currently in the idle pure electric four-wheel drive mode, if the mode switching condition for switching from the idle pure electric four-wheel drive mode to the series mode is met, it means that the current target operation mode is the series mode. At this time, although the target operation mode is the series mode, it will not follow the conventional control method, that is, the VCU will send an idle request signal indicating that the idle is not activated to the engine controller to request the engine to exit the idle state, but the VCU will continue to send an idle request signal carrying the first signal value to the engine controller during the mode switching process to request the engine to continue to activate the idle state, so that the vehicle maintains the same control method as the idle pure electric four-wheel drive mode during the process of switching from the idle pure electric four-wheel drive mode to the series mode, avoiding the torque control right from the engine controller ECM to the vehicle controller VCU, that is, during the process of switching from the idle pure electric four-wheel drive mode to the series mode, the engine's torque control right is still ECM, which is conducive to avoiding the phenomenon of the engine speed fluctuating, thereby improving the driver experience during the mode switching process.

[0068] Below Figure 7 The specific implementation of each step in the embodiment shown is described as follows:

[0069] In step 701, the vehicle is a hybrid vehicle, and the architecture diagram of the hybrid vehicle can be as shown above. Figure 1 As shown. When the vehicle is currently in the idle pure electric four-wheel drive mode, there is a possibility of switching to other operating modes. Since the vehicle is in a dynamic driving process, the operating mode suitable for the vehicle may also change dynamically. In this embodiment, attention is paid to the problem of switching between the idle pure electric four-wheel drive mode and the series mode. Therefore, in this embodiment, when the vehicle is currently in the idle pure electric four-wheel drive mode, it is determined whether the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met.

[0070] Among them, the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode can be pre-calibrated to indicate the conditions under which the vehicle is suitable for being in the series mode. For example, when the target operating mode of the vehicle changes from the idle pure electric four-wheel drive mode to the series mode, it can be determined that the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met. The target operating mode is the operating mode that the vehicle is expected to be in. The target operating mode is the operating mode that the VCU determines to be suitable for the vehicle based on vehicle condition data such as current driving needs, road conditions, and vehicle status (such as vehicle speed, load). Related to the target operating mode is the actual operating mode, which is the operating mode that the vehicle is actually in at the current moment. During vehicle operation, the target operating mode and the actual operation may be the same or different.

[0071] In one possible implementation, the above judgment whether the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met includes: obtaining the vehicle's current remaining power, current gear, current energy mode and driving mode; if the vehicle's remaining power is less than a preset power threshold, it is determined that the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met; if the current combination of the energy mode and the driving mode meets the preset combination conditions, and the current gear is P gear, it is determined that the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met; wherein the preset combination conditions include: the current energy mode is pure electric priority mode or hybrid mode, and the driving mode is AWD mode, snow mode, mud mode or sand mode.

[0072] Among them, the current remaining power refers to the current remaining power of the vehicle's battery pack. The current gear may be any of the following gears: parking gear (P gear), forward gear (D gear), reverse gear (R gear), and neutral gear (N gear). The current energy mode may be any of the following: forced pure electric mode (Force EV), pure electric priority mode (EV), and hybrid mode (HEV). The current driving mode may be any of the following: economic mode (ECO), standard mode (Normal), sports mode (Sport), four-wheel drive mode (AWD), snow mode (SNOW), mud mode (MUD), and sand mode (SAND). In the specific implementation, the vehicle is provided with a selection button for the driving mode and energy mode, and the driver can select the driving mode and energy mode that he currently wants to enter by selecting the button. These driving modes are introduced below:

[0073] Standard mode (Normal): This mode mainly takes into account the power and economy of the vehicle, that is, balancing power and fuel efficiency. It is suitable for daily use and the driving style of the vehicle is relatively conventional.

[0074] Sport mode: In this mode, the accelerator pedal is sensitive, acceleration is fast, the transmission delays shifting, the vehicle's power is increased, and the driving style of the vehicle tends to be intense.

[0075] Economic mode (ECO): In this mode, the engine power output is smooth and the transmission shifts actively. The vehicle's power is reduced and its economy is increased. It is used to optimize fuel efficiency and reduce fuel consumption. The driving style of the whole vehicle tends to be smooth and gentle.

[0076] Sand mode (SAND): Mainly used for driving in deserts and Gobi or off-road driving, the purpose is to ensure that the vehicle does not get stuck in sand pits during driving. In sand mode, the traction control system is in a non-intervention state. Both sudden acceleration and sudden braking in sand mode are dangerous. Therefore, the braking distance may increase in this driving mode. In sand mode, the vehicle mainly limits the torque output of the vehicle by controlling the slip rate.

[0077] Snow mode (SNOW): Mainly used for driving under low adhesion conditions or off-road driving. In this driving mode, the engine power output is limited, acceleration is smooth, traction is increased, and the vehicle is prevented from slipping during driving. In snow mode, the vehicle's traction control system is always activated, giving better power distribution to the four wheels when slipping.

[0078] Mud mode (MUD): Mainly used for driving in deep and shallow mud or off-road driving, the purpose is to get the vehicle out of trouble. In Mud mode, the Electronic Stability Controller (ESC) is always in a "partially closed" state, that is, when the vehicle slips laterally, the vehicle chooses not to turn on the ESC to brake the slipping tires, so that the wheels have greater adhesion, which is suitable for muddy road conditions.

[0079] AWD (All-Wheel Drive) mode is an optional four-wheel drive mode. In this mode, the goal is to ensure the driver has the best driving performance when driving off-road or assisting the driver in climbing steep slopes. Four-wheel drive means that the vehicle maintains four-wheel drive throughout the entire driving process, and the engine output torque is distributed to the front and rear wheels in a preset ratio. This driving mode can always have better off-road and handling performance. When the driver selects the AWD mode through the driving mode selection button, it does not mean that the vehicle can directly enter the four-wheel drive. It also needs to be further combined with the energy mode selected by the driver. If the driver selects the hybrid mode or the pure electric priority mode, the vehicle can truly enter the four-wheel drive.

[0080] Specifically, in the following two cases, the VCU can determine that the switching conditions from the idle pure electric four-wheel drive mode to the series mode are met:

[0081] Case 1: If the remaining power of the vehicle is less than the preset power threshold, the VCU determines that the switching conditions from the idle pure electric four-wheel drive mode to the series mode are met.

[0082] Among them, the preset power threshold can be calibrated in advance. The preset power threshold is intended to measure whether the current remaining power (SOC, State Of Charge) of the vehicle's battery pack is too low and whether it needs to be charged. For example, the preset power threshold can be calibrated to 13%. If the current remaining power is less than the preset power threshold, it means that the current remaining power is too low and it is necessary to enter the series mode to charge the vehicle's battery pack. At this time, regardless of the current energy mode and driving mode, since the current remaining power is too low, it can be forced to enter the series mode to charge the battery pack. If the current remaining power is greater than the preset power threshold, it means that the current remaining power is sufficient and there is no need to enter the series mode for charging.

[0083] Case 2: If the current combination of energy mode and driving mode meets the preset combination conditions, and the current gear is P, it is determined that the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met.

[0084] Among them, the combinations of energy modes and driving modes that meet the preset combination conditions include: the combination of pure electric priority mode and AWD mode, the combination of pure electric priority mode and snow mode, the combination of pure electric priority mode and mud mode, the combination of pure electric priority mode and sand mode, the combination of hybrid mode and AWD mode, the combination of hybrid mode and snow mode, the combination of hybrid mode and mud mode, and the combination of hybrid mode and sand mode.

[0085] Since the electric priority mode and hybrid mode are strong power modes compared to the forced electric mode, that is, energy modes with stronger power requirements, and the AWD mode, snow mode, mud mode and sand mode are strong driving modes compared to the economic mode, standard mode and sports mode, that is, driving modes with stronger power requirements, in the combination of the above driving mode and energy mode with stronger power requirements, starting the engine is conducive to the engine's rapid torque output, which is conducive to meeting its high power requirements. Therefore, if the current combination of energy mode and driving mode meets the preset combination conditions, and the current gear is P gear, it indicates that there is no driving demand at present, but after exiting P gear, there is a demand for the engine to quickly output torque, so the series mode can be entered to recharge the battery pack of the vehicle to ensure that the battery pack has sufficient power. At the same time, since the engine is started in the series mode, it is conducive to the engine that has been started to quickly output torque after exiting P gear, so as to quickly improve the vehicle's power and meet the vehicle's strong power requirements under the combination of the above specific driving mode and energy mode.

[0086] In step 702, if the switching condition is met, the idle request signal carrying the first signal value is continuously sent to the engine controller ECM during the mode switching process, so that the ECM continuously controls the engine to activate the idle state. Figure 6 In the mode switching process shown (torque reduction, gear shifting, speed regulation), the idle request signal actually carries the second signal value, which is used to indicate that the engine does not activate the idle state. Figure 6 The change curve of the idle request signal in the mode switching process is "inactive". In the embodiment of the present application, in the process of mode switching, the VCU keeps sending the idle request signal carrying the first signal value to the engine controller ECM, and does not send the idle request signal carrying the second signal value. Therefore, in the process of mode switching, the engine in the embodiment of the present application still maintains the idle state like the idle pure electric four-wheel drive mode, and will not exit the idle state. This further makes it possible to maintain the same engine idle control method as the idle pure electric four-wheel drive mode during the mode switching process, thereby avoiding the change of torque control authority during the mode switching process, which is conducive to avoiding the phenomenon of engine speed fluctuating during the mode switching process.

[0087] In one possible implementation, if the current actual operating mode is the idle pure electric four-wheel drive mode, the target operating mode is the series mode and the clutch is in a disengaged state, it is determined that the vehicle is currently in the above-mentioned mode switching process, that is, switching from the idle pure electric four-wheel drive mode to the series mode.

[0088] In an exemplary embodiment, the series mode is a first series mode or a second series mode. In the first series mode, the engine is in an idle state, and in the second series mode, the engine is in a non-idle state. After the above step 702, it also includes: if it is detected that the vehicle has switched from the idle pure electric four-wheel drive mode to the first series mode, then continue to send an idle request signal carrying a first signal value to the engine controller; if it is detected that the vehicle has switched from the idle pure electric four-wheel drive mode to the second series mode, then send an idle request signal carrying a second signal value to the engine controller; wherein the second signal value is used to instruct the engine controller ECM not to activate the idle state of the engine.

[0089] In this embodiment, the series connection mode is divided into two categories according to whether the engine is in an idle state, namely the first series connection mode and the second series connection mode mentioned above. In the first series connection mode, the rear drive motor is in a driving state, the engine runs at an idle speed to drive the front drive motor to generate electricity, and the clutch is in a closed state. Therefore, the first series connection mode can also be referred to as a series connection idle mode. In the second series connection mode, the rear drive motor is in a driving state, the engine runs at a non-idling speed to drive the front drive motor to generate electricity, and the clutch is in a closed state. Therefore, the second series connection mode can also be referred to as a series connection non-idling mode or a stable series connection mode. It can be understood that since the engine runs at an idle speed in the first series connection mode and runs at a non-idling speed in the second series connection mode, the power generation capacity of the engine in the first series connection mode is usually higher than the power generation capacity in the second series connection mode.

[0090] Exemplarily, when it is determined that the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met, if it is further detected that the current vehicle speed is less than or equal to the preset vehicle speed threshold, then it is determined that the series mode switched from the idle pure electric four-wheel drive mode is the first type of series mode; if it is further detected that the current vehicle speed is greater than the preset vehicle speed threshold, then it is determined that the series mode switched from the idle pure electric four-wheel drive mode is the second type of series mode.

[0091] Among them, the preset speed threshold can be pre-calibrated, and the preset speed threshold is intended to measure whether the current speed of the vehicle is suitable for the engine to be in an idle state. For example, the preset speed threshold can be calibrated to 30km / h. If the current speed is less than or equal to 30km / h, it means that the speed is low and suitable for the engine to be in an idle state. If the current speed is greater than 30km / h, it means that the speed is relatively high and is not suitable for the engine to be in an idle state, that is, the engine in an idle state cannot meet the high speed demand.

[0092] Exemplarily, when it is determined that the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met, if it is further detected that the battery pack temperature of the vehicle is lower than the first temperature threshold, or the coolant temperature of the engine is lower than the second temperature threshold, then it is determined that the series mode switched from the idle pure electric four-wheel drive mode is the first type of series mode; if it is further detected that the battery pack temperature of the vehicle is greater than or equal to the first temperature threshold and the coolant temperature of the engine is greater than or equal to the second temperature threshold, then it is determined that the series mode switched from the idle pure electric four-wheel drive mode is the second type of series mode.

[0093] Among them, the first temperature threshold and the second temperature threshold can be pre-calibrated to measure whether the battery pack temperature or the coolant temperature is too low. When the battery pack temperature of the vehicle is lower than the first temperature threshold, it means that the battery pack temperature is too low. When the engine coolant temperature is lower than the second temperature threshold, it means that the engine coolant temperature is too low. The first temperature threshold and the second temperature threshold can be the same or different. In this embodiment, the first temperature threshold and the second temperature threshold can be calibrated to -20°.

[0094] When the battery pack temperature is too low or the engine coolant temperature is too low, its performance will decline, which may cause the battery pack to be unable to charge or discharge effectively. At the same time, the engine's operating efficiency will also be affected, and it may not be able to generate electricity effectively or its power generation capacity may be limited in the early stage. At this time, if the engine is allowed to run at idle speed first, the heat generated by the engine's own idling operation will help gradually increase the coolant temperature, thereby increasing the temperature of the engine and peripheral systems such as the battery pack, so that the engine's coolant temperature and battery pack temperature gradually return to the normal operating temperature range, and the power generation capacity will increase accordingly.

[0095] In one possible implementation, if the VCU detects that the vehicle has switched from the idle pure electric four-wheel drive mode to the first type of series mode, it means that the engine is still in the idle state after switching to the first type of series mode. Therefore, the VCU continues to send an idle request signal carrying a first signal value to the engine controller to continue to activate the idle state of the engine, thereby meeting the requirement that the engine is in the idle state in the first type of series mode.

[0096] In another possible implementation, if the VCU detects that the vehicle has switched from the idle pure electric four-wheel drive mode to the second type of series mode, it means that after switching to the second type of series mode, the engine needs to exit the idle state. Therefore, the VCU sends an idle request signal carrying a second signal value to the engine controller so that the idle state of the engine is not activated, that is, the engine is instructed to exit the idle state, thereby meeting the requirement that the engine is in a non-idle state in the second type of series mode.

[0097] It can be understood that, in this embodiment, during the process of switching from the idle pure electric four-wheel drive mode to the series mode, although the target operating mode is not the idle pure electric four-wheel drive mode, but the series mode, the VCU continues to send an idle request signal carrying the first signal value to the engine controller, so that during the mode switching process, the engine remains in an idle state, and the engine controller ECM controls the engine torque. There is no change in torque control during this mode switching process. After the clutch is closed to enter the series mode, based on whether the entered series mode is the first type of series mode or the second type of series mode, it is determined whether the idle request signal sent to the engine controller carries the first signal value or the second signal value. Specifically, if the series mode entered after the clutch is closed is the first type of series mode, that is, the idle pure electric four-wheel drive mode has been switched to the first type of series mode, then the VCU continues to send an idle request signal carrying the first signal value to continue to activate the idle state of the engine. If the series mode entered after the clutch is closed is the second type of series mode, that is, the idle pure electric four-wheel drive mode has been switched to the second type of series mode, the VCU sends an idle request signal carrying a second signal value to instruct the engine not to activate the idle state, that is, to instruct the engine to exit the idle state.

[0098] In an exemplary embodiment, when the vehicle has switched from the idle pure electric four-wheel drive mode to the first type of series mode, the VCU sends a target idle speed to the engine controller so that the engine controller can control the idle speed of the engine according to the target idle speed.

[0099] Specifically, when the vehicle has switched from the idle pure electric four-wheel drive mode to the first type of series mode, the VCU continues to request the engine's idle state to be activated, that is, the engine is still in the idle state, so the current power control mode for the vehicle is still engine-controlled idle. Specifically, since the actual operating mode at this time is no longer the idle pure electric four-wheel drive mode, but the first type of series mode, the VCU can determine that the target idle speed of the engine is a pre-calibrated series idle speed, and send the series idle speed as the target idle speed to the engine controller, so that the engine controller controls the idle speed of the engine according to the target idle speed sent by the VCU. The series idle speed is used to make the engine idle in the first type of series mode to drive the front drive motor to generate electricity.

[0100] The series idle speed can be pre-calibrated according to actual needs. If a large amount of charging is required, the series idle speed can be calibrated to be larger. If a small amount of charging is required, the series idle speed can be calibrated to be smaller. To ensure that the engine can run at idle speed, the series idle speed can be calibrated between 1500rpm and 2500rpm in this embodiment to avoid the engine being stopped during idling to drive the front drive motor to generate electricity.

[0101] Optionally, different series idle speeds can be calibrated for different vehicle condition data to obtain the corresponding relationship between the vehicle condition data and the series idle speed. For example, the corresponding relationship between vehicle condition data such as the remaining power SOC of the battery pack, the coolant temperature of the engine, and the rechargeable power of the battery pack and the series idle speed can be calibrated. Therefore, when the series idle speed needs to be determined later, the VCU can determine the series idle speed corresponding to the current vehicle condition data based on the corresponding relationship, so that the determined series idle speed is more suitable for the current vehicle condition data.

[0102] In an exemplary embodiment, when the vehicle has switched from the idle pure electric four-wheel drive mode to the second type series mode, the VCU requests the engine to output a pre-calibrated power generation torque corresponding to the current vehicle condition data.

[0103] Specifically, when the vehicle has switched from the idle pure electric four-wheel drive mode to the second type of series mode, the VCU requests the engine to exit the idle state, and the power control mode of the vehicle will be changed from the above-mentioned engine idle control to the VCU requesting the engine to output a pre-calibrated power generation torque corresponding to the current vehicle condition data. In other words, the engine torque requested by the VCU is a pre-calibrated power generation torque, which is equal to the negative front drive motor torque. Since the calibrated power generation torque is a stable torque value, the VCU will not PI adjust the requested engine torque, which is conducive to avoiding fluctuations in the engine torque requested by the VCU and fluctuations in the actual engine speed.

[0104] In a possible implementation, the correspondence between vehicle condition data and power generation torque can be pre-calibrated, for example, the correspondence between vehicle condition data such as engine target speed and battery pack chargeable power and power generation torque can be calibrated. Therefore, when the power generation torque needs to be determined later, the VCU can determine the power generation torque corresponding to the current vehicle condition data based on the correspondence, so that the determined power generation torque is more suitable for the current vehicle condition data.

[0105] In one possible implementation, when vehicle startup is detected, an idle request signal, an idle speed signal, and an idle load torque signal are sent to an engine controller, so that the engine controller activates the idle state of the engine based on a first signal value carried in the idle request signal, or does not activate the idle state of the engine based on a second signal value carried in the idle request signal, and instructs the engine controller to control the idle speed of the engine based on the target idle speed carried in the idle speed signal and to control the idle torque of the engine based on the target idle torque carried in the idle load torque signal when the idle state of the engine is activated.

[0106] Among them, the first signal value is used to instruct the engine controller ECM to activate the idle state of the engine, and the second signal value is used to instruct the engine controller ECM not to activate the idle state of the engine. Optionally, the first signal value can be represented as "1" and the second signal value can be represented as "0". When the VCU wants to control the engine to activate the idle state, an idle request signal carrying "1" can be sent to the engine controller. When the VCU wants to control the engine to exit the idle state or deactivate the idle state, an idle request signal carrying "0" can be sent to the engine controller.

[0107] It is understandable that after the vehicle is started, the VCU can always send the following key signals to the transmitter controller: an idle request signal, an idle speed signal, and an idle load torque signal. Whether the idle request signal carries the first signal value or the second signal value, the specific size of the target idle speed carried in the idle speed signal, and the specific size of the target idle torque carried in the idle load torque signal are all determined according to the actual state of the vehicle operation, and they may be different values ​​at different times. However, only when the idle request signal carries the first signal value, that is, when the ECM activates the idle state of the engine, the ECM will control the idle speed of the engine based on the target idle speed carried in the idle speed signal, and control the idle torque of the engine based on the target idle torque carried in the idle load torque signal. If the idle request signal carries the second signal value, the ECM will not pay attention to the idle speed signal and the idle load torque signal, and even if the idle speed signal and the idle load torque signal are received, the idle speed and idle torque of the engine will not be controlled according to the target idle speed carried in the idle speed signal and the target idle torque carried in the idle load torque signal.

[0108] The engine's idle torque, also known as idle load torque, refers to the minimum torque required for the engine to maintain its own operation and overcome internal friction and accessory equipment (such as water pumps, air conditioning compressors, etc.) when the engine is in an idle state (i.e., the engine does not need to output power to drive the vehicle). In this state, the torque output by the engine is mainly used for self-maintenance to ensure stable operation of the engine, rather than for driving the vehicle forward. When the engine is idling, the engine speed is relatively low, and the torque required is mainly to overcome internal resistance, so the idle load torque is relatively small, and ideally it can be 0.

[0109] In an exemplary embodiment, after the vehicle is started, the VCU will also send a driving torque signal to the engine controller, which carries the driving torque of the engine. The driving torque of the engine refers to the torque provided by the engine when it outputs power to drive the vehicle forward. When the driver steps on the accelerator and requires the vehicle to accelerate or maintain a certain speed, the engine needs to output a larger torque to overcome external resistance (such as wind resistance, road friction, climbing resistance, etc.) and the dynamic load of the vehicle. Among them, the driving torque of the engine is also the engine torque requested by the VCU mentioned above.

[0110] When the engine is in an idle state, the driving torque carried in the above-mentioned driving torque signal is a preset friction torque, and the preset friction torque is a negative value, such as -13NM. When the engine is in a non-idle state, the driving torque carried in the driving torque signal is the engine fast-path torque calculated based on the normal torque path. Specifically, the engine fast-path torque can be a target engine torque value calculated by the VCU based on multiple factors such as the current vehicle speed, accelerator pedal position, vehicle load, road slope, etc. This value reflects the torque that the engine should output under the current working conditions in order to meet the power demand and maintain the normal operation of the vehicle.

[0111] In an exemplary embodiment, the first signal value or the second signal value carried in the idle request signal is determined by:

[0112] When the preset idle activation condition is met, it is determined that the idle request signal carries a first signal value; when the preset idle activation condition is not met, it is determined that the idle request signal carries a second signal value.

[0113] The idle activation condition includes: a first preset condition, a second preset condition or a third preset condition. That is, if any one of the first preset condition, the second preset condition or the third preset condition is met, it can be determined that the idle activation condition is met. If none of the first preset condition, the second preset condition or the third preset condition is met, it can be determined that the idle activation condition is not met. The three preset conditions are described below respectively:

[0114] The first preset condition includes: the target operation mode is the idle pure electric four-wheel drive mode. It is understandable that if the current target operation mode is the idle pure electric four-wheel drive mode, it means that the vehicle is suitable to be in the idle pure electric four-wheel drive mode next, and the engine is in the idle state in the idle pure electric four-wheel drive mode, so it is determined that the idle request signal carries the first signal value to meet the requirement that the engine needs to be in the idle state in the idle pure electric four-wheel drive mode. And, if the current target operation mode is the idle pure electric four-wheel drive mode, and the current actual operation mode is not the idle pure electric four-wheel drive mode, it means that the vehicle's operation mode should be switched to the idle pure electric four-wheel drive mode. If the current target operation mode and the actual operation mode are both the idle pure electric four-wheel drive mode, it means that the vehicle should continue to remain in the idle pure electric four-wheel drive mode.

[0115] Exemplarily, if the following four conditions are met at the same time, the target operation mode is determined to be the idle pure electric four-wheel drive mode:

[0116] Condition 1: The vehicle's current remaining power is greater than the preset power threshold; and,

[0117] Condition 2: The current speed of the vehicle is less than or equal to the preset speed threshold; and,

[0118] Condition 3: The vehicle's current gear is not P; and,

[0119] Condition 4: When the vehicle's current energy mode is pure electric priority mode or hybrid mode, the driving mode is AWD mode, snow mode, mud mode or sand mode.

[0120] The preset power threshold in the above condition 1 can be calibrated in advance. The preset power threshold is intended to measure whether the current remaining power SOC of the vehicle is too low and whether it needs to be charged. For example, the preset power threshold can be calibrated to 13%. If the current remaining power is greater than the preset power threshold, it means that the current remaining power is sufficient to support the vehicle's subsequent switching to the idle pure electric four-wheel drive mode and operation in the idle pure electric four-wheel drive mode. If the current remaining power is less than or equal to the preset power threshold, it means that the current remaining power is insufficient. If you continue to switch to the idle pure electric four-wheel drive mode, the remaining power of the vehicle may continue to decrease, causing the remaining power of the vehicle to be too low, affecting the normal power supply to the vehicle components, and then affecting the normal operation of the vehicle. In a specific implementation, if the current remaining power is less than or equal to the preset power threshold, the vehicle can be controlled to enter the series mode to charge the battery pack.

[0121] The preset speed threshold in the above condition 2 can be pre-calibrated. The preset speed threshold is intended to measure whether the current speed of the vehicle is suitable for the engine to be in the idle state. For example, the preset speed threshold can be calibrated to 30km / h. If the current speed is less than 30km / h, it means that the speed is low and is suitable for the engine to be in the idle state. If the current speed is greater than 30km / h, it means that the speed is high and is not suitable for the engine to be in the idle state. The idle pure electric four-wheel drive mode should not be entered, but the direct drive mode should be entered.

[0122] The current gear in the above condition 3 is not the P gear, that is, the current gear is any one of the R gear, N gear, and D gear. Since the P gear indicates that there is no driving demand at present, if the current gear is the P gear, there is no need to enter the idle pure electric four-wheel drive mode. As for the N gear, considering that the driver has a process of switching from D gear to N gear and then back to D gear during driving, therefore, in this embodiment, the N gear is also used as one of the conditions, which is conducive to avoiding frequent exit and entry of the idle pure electric four-wheel drive mode in the process of switching from D gear to N gear and then back to D gear, and thus helps to avoid frequent engine start and stop. For example, if the N gear is not used as a gear that allows entry into the idle pure electric four-wheel drive mode, then in the process of switching from D gear to N gear and then back to D gear, the idle pure electric four-wheel drive mode will exit and then enter first, resulting in the meaningless frequent exit and entry of the idle pure electric four-wheel drive mode in a short period of time. For the R gear, considering that the vehicle has a forward, backward, forward, backward cycle, therefore, the R gear is also used as one of the conditions, which is conducive to avoiding frequent exit and entry of the idle pure electric four-wheel drive mode in the above forward, backward, forward, backward cycle, and thus helps to avoid frequent engine start and stop. For example, if the R gear is not used as a gear position that allows entry into the idle pure electric four-wheel drive mode, then in the above forward, backward, forward, backward process, the idle pure electric four-wheel drive mode will be entered when the vehicle is moving forward and exited when the vehicle is moving backward, resulting in frequent exit and entry of the idle pure electric four-wheel drive mode in a short period of time.

[0123] In the above condition 4, considering that the engine is not started in the forced pure electric mode, if the current energy mode is the forced pure electric mode, it can be directly determined that condition 4 is not met. In the AWD (All-Wheel Drive) mode, snow mode, mud mode or sand mode, the requirement for driving force is usually high. Therefore, if the current energy mode is the pure electric priority mode or hybrid mode, and the driving mode is the AWD mode, snow mode, mud mode or sand mode, it is determined that condition 4 is met, which is conducive to utilizing the higher driving force provided by the idle pure electric four-wheel drive mode to meet the high driving force requirements of the current energy mode and driving mode.

[0124] For example, the above condition 4 can be found in the following table 1, "√" represents a combination of energy mode and driving mode that meets condition 4, and "×" represents a combination of energy mode and driving mode that does not meet condition 4. Specifically, if the current energy mode is pure electric priority mode, and the current driving mode is AWD mode, snow mode, mud mode or sand mode, it is determined that condition 4 is met. If the current energy mode is hybrid mode, and the current driving mode is AWD mode, snow mode, mud mode or sand mode, it is determined that condition 4 is met.

[0125] Table 1

[0126] ECO Normal Sport AWD Snow Mud Sandy Mandatory pure electric × × × × × × × Pure electric priority × × × √ √ √ √ Hybrid × × × √ √ √ √

[0127] The second preset condition includes: the actual operation mode is the idle pure electric four-wheel drive mode, the target operation mode is the series mode and the clutch is in a disengaged state.

[0128] Combined with the above description, it can be seen that if the second preset condition is met, it means that the current mode is in the process of switching from the idle pure electric four-wheel drive mode to the series mode. During this mode switching process, in order to avoid changes in torque control rights, the VCU continues to send an idle request signal carrying a first signal value to the engine controller ECM. Therefore, when the second preset condition is met, it is determined that the preset idle activation condition is met, so that the VCU continues to send an idle request signal carrying a first signal value to the engine controller to activate the idle state of the engine, thereby avoiding the engine speed from fluctuating due to changes in power control rights during the mode switching process.

[0129] The third preset condition includes: the battery pack temperature of the vehicle is lower than the first temperature threshold, or the coolant temperature of the engine is lower than the second temperature threshold.

[0130] Among them, the first temperature threshold and the second temperature threshold can be pre-calibrated to measure whether the battery pack temperature or the coolant temperature is too low. When the battery pack temperature of the vehicle is lower than the first temperature threshold, it means that the battery pack temperature is too low, and when the engine coolant temperature is lower than the second temperature threshold, it means that the engine coolant temperature is too low. When the battery pack temperature is too low or the engine coolant temperature is too low, its performance will decline, which may cause the battery pack to be unable to charge or discharge effectively. At the same time, the operating efficiency of the engine will also be affected, and it may not be able to generate electricity effectively or its power generation capacity may be limited in the initial stage. At this time, if the engine is allowed to run in an idle state first, the heat generated by the engine's own idling operation will help to gradually increase the coolant temperature, thereby increasing the temperature of the engine and peripheral systems such as the battery pack, so that the engine coolant temperature and battery pack temperature gradually return to the normal operating temperature range, and the power generation capacity will increase accordingly. Therefore, in this embodiment, when the third preset condition is met, it is determined that the preset idle activation condition is met, so that the VCU sends an idle request signal carrying a first signal value to the engine controller to activate the idle state of the engine, which is beneficial to the heat generated by the idle operation of the engine itself, so that the engine coolant temperature and the battery pack temperature gradually return to the normal operating temperature range, and the power generation capacity is improved accordingly.

[0131] In an exemplary embodiment, there are two ways to determine the target idle speed carried in the idle speed signal:

[0132] Method 1: When the actual operation mode of the vehicle is not the idle pure electric four-wheel drive mode, the pre-calibrated series idle speed is determined as the target idle speed. The series idle speed is used to make the engine idle in the series mode to drive the front drive motor to generate electricity.

[0133] Specifically, when the actual operation mode of the vehicle is not the idle pure electric four-wheel drive mode, it means that the current actual operation mode may be the series mode, which is specifically the first type of series mode when the above-mentioned engine is in the idle state. Combined with the above description, when the VCU requests the engine to activate the idle speed, the engine controller controls the idle speed of the engine based on the target idle speed sent by the VCU. If the actual operation mode is indeed the series mode, the engine controller will be able to control the idle speed of the engine according to the series idle speed sent by the VCU, so that the engine idles to drive the front drive motor to generate electricity, so as to realize the charging of the vehicle battery pack. Therefore, when the actual operation mode of the vehicle is not the idle pure electric four-wheel drive mode, the pre-calibrated series idle speed is determined as the target idle speed, which is conducive to the charging of the vehicle when the actual operation mode of the vehicle is the series mode. Among them, the pre-calibrated series idle speed has been described above and will not be repeated here.

[0134] Method 2: When the actual operating mode of the vehicle is the idle pure electric four-wheel drive mode, the VCU first determines the current target operating mode of the vehicle, and then determines the target idle speed of the engine based on the current target operating mode.

[0135] In an exemplary embodiment, the above-mentioned implementation method of determining the target idle speed of the engine according to the current target operation mode includes the following three situations:

[0136] Case 1: If the current target operation mode is the series mode, the VCU determines the pre-calibrated series idle speed as the target idle speed;

[0137] It can be understood that if the current target operation mode is the series mode and the actual operation mode is the idle pure electric four-wheel drive mode, it means that the vehicle is in the process of switching from the idle pure electric four-wheel drive mode to the series mode with the engine in the idle state (that is, the first type of series mode mentioned above). In this case, the VCU can directly determine the pre-calibrated series idle speed as the target idle speed, that is, before the vehicle enters the series mode, the engine idle speed has been adjusted to the series idle speed required by the series mode, so that after the vehicle enters the series mode with the engine in the idle state, there is no need to adjust the engine idle speed to achieve charging of the vehicle.

[0138] Case 2: If the current target operation mode is the direct drive mode, the VCU determines the target engine speed sent by the TCU as the target idle speed; wherein, the target engine speed sent by the TCU is calculated by the TCU based on the current gear position and the current vehicle speed.

[0139] It can be understood that if the current target operation mode is the direct drive mode and the actual operation mode is the idle pure electric four-wheel drive mode, it means that the vehicle is in the process of switching from the idle pure electric four-wheel drive mode to the direct drive mode. During this process, the TCU calculates the engine target speed based on the current gear position and the current vehicle speed, and sends the engine target speed to the VCU. The VCU determines the engine target speed calculated by the TCU based on the current gear position and the current vehicle speed as the target idle speed.

[0140] The process of realizing the target engine speed calculated based on the current gear and the current vehicle speed is actually the process of inferring the target engine speed based on the current gear and the vehicle speed, and is essentially to determine an ideal engine operating state to match the current driving demand. This process needs to consider the vehicle's transmission ratio, wheel size, vehicle speed, and vehicle performance parameters, including the following S21 to S23:

[0141] S21: Determine the speed ratio of the current gear.

[0142] Specifically, the current gear here is actually the 1st gear, 2nd gear, 3rd gear, 4th gear, etc. The speed ratio refers to the ratio of the output shaft speed of the gearbox to the input shaft speed (i.e., the engine speed). For example, the 1st gear may have a higher speed ratio, which means that the engine speed is high and the wheel speed is low, which is suitable for starting or climbing; while the 5th gear or 6th gear has a lower speed ratio, which is suitable for high-speed driving.

[0143] S22: Determine the wheel speed according to the current vehicle speed. Specifically, the current vehicle speed (kilometers per hour) can be converted into the wheel speed (revolutions per minute) according to the diameter of the wheel.

[0144] S23: Calculate the target engine speed according to the speed ratio of the current gear and the wheel speed.

[0145] Specifically, if the speed ratio is i and the wheel speed is N_wheel, the target engine speed N_engine can be calculated by the following formula: N_engine=N_wheel×i. For example, assuming that the vehicle is running in 5th gear, the speed ratio of the 5th gear is 0.8, the vehicle speed is 80 km / h, and the wheel circumference is 2 meters, then the wheel speed is about 74.07 rpm. Based on the speed ratio of 0.8, the target engine speed is about 59.26 rpm.

[0146] Case 3: If the current target operating mode is the idle pure electric four-wheel drive mode, the engine target speed calculated by the VCU based on the current gear position and the current vehicle speed is determined as the target idle speed.

[0147] It is understandable that if the current target operation mode and the actual operation mode are both the idle pure electric four-wheel drive mode, that is, the current mode is stable at the idle pure electric four-wheel drive mode. In this case, the VCU determines the target idle speed as the engine target speed calculated based on the current gear and the current vehicle speed. The way the VCU calculates the engine target speed is the same as the way the TCU calculates the engine target speed mentioned above, that is, the engine target speeds in Case 2 and Case 3 are calculated based on the same calculation logic, except that the engine target speed in Case 2 is calculated by the TCU, and the engine target speed in Case 3 is calculated by the VCU.

[0148] In Case 2 and Case 3, although the logic for calculating the target engine speed is the same, since parameters such as vehicle speed and gear position change dynamically, and the calculation times of VCU and TCU are not exactly the same (for example, VCU usually calculates unless TCU intervenes. TCU usually intervenes for a short while in the speed regulation process of switching from idle pure electric four-wheel drive mode to direct drive mode, and TCU stops calculating when the speed is adjusted to meet the requirements), there will be differences in the results of the two calculations, but the differences will not be too large. For example, the result calculated by VCU is 1500rpm, and the result calculated by TCU is 1550rpm.

[0149] Considering that after the subsequent idle pure electric four-wheel drive mode is exited, most working conditions will enter the direct drive mode (a few working conditions will enter the series mode), and entering the direct drive mode requires the TCU to control the clutch to close. When the TCU controls the clutch to close, it is necessary to determine that the conditions for closing the clutch are met when the speed difference between the actual engine speed and the target engine speed calculated by the TCU is less than the preset difference threshold, and then control the clutch to close. When the speed difference between the actual engine speed and the target engine speed calculated by the TCU is greater than or equal to the preset difference threshold, it is necessary to adjust the speed of the engine, that is, adjust the speed of the engine, so that the speed difference between the actual engine speed and the target engine speed calculated by the TCU is less than the preset difference threshold. Therefore, if the target idle speed is set to a fixed value (such as 1100rpm) when it is currently stable in the idle pure electric four-wheel drive mode, that is, in the idle pure electric four-wheel drive mode, the actual speed of the engine will follow the 1100rpm. If the conditions for entering the direct drive mode from the idle pure electric four-wheel drive mode are met later, such as stepping on the accelerator to accelerate, and the vehicle speed rises to above 30km / h (corresponding to the engine speed of 1500rpm), the target operation mode is the direct drive mode, which is equivalent to the goal of the mode switch at this time to exit the idle pure electric four-wheel drive mode. If the target operation mode becomes the direct drive mode, the idle request sent by the VCU to the engine controller will carry the second signal value to indicate that the engine exits the idle state, then the VCU will not send an idle speed request with a target idle speed of 1100rpm. At this time, the normal torque path is taken, and the TCU sends a TCU speed control instruction to the VCU to instruct the VCU to control the engine speed according to the engine target speed sent by the TCU. The TCU sends the engine target speed (for example, 1550rpm) to the VCU. The VCU adjusts the engine torque requested by the VCU through the proportional integral adjustment method according to the speed difference between the engine target speed sent by the TCU and the actual engine speed, so that the actual engine speed reaches this engine target speed. Since the actual engine speed is 1100rpm and the target engine speed is 1550rpm at this time, the speed difference between the two is large, and the speed adjustment requires a certain amount of time. After the speed is adjusted, the TCU will close the clutch and the engine can produce torque. The torque output process is not fast, and there is an excessive speed adjustment process.

[0150] Therefore, in order to avoid the problem of long speed regulation time and slow torque output during the process of switching the above-mentioned idling pure electric four-wheel drive mode to the direct drive mode, in this embodiment, when the idling pure electric four-wheel drive mode is currently stable, the VCU will not use the fixed value as the target idle speed, but will determine the target idle speed as the target engine speed calculated by the VCU itself based on the current gear and the current vehicle speed. Then, in the idling pure electric four-wheel drive mode, the actual engine speed will follow the target idle speed. If the conditions for entering the direct drive mode are met later, such as stepping on the accelerator to accelerate, and the vehicle speed rises to above 30km / h, the target operation mode is the direct drive mode, which is equivalent to the goal of the mode switching at this time to exit the idling pure electric four-wheel drive mode. At this time, the normal torque path is taken, and the TCU sends the engine target speed (such as 1550rpm) to the VCU. The VCU adjusts the output torque of the engine according to the speed difference between the engine target speed sent by the TCU and the actual engine speed, so that the actual engine speed reaches the target engine speed. Since the actual engine speed at this time follows the engine target speed calculated by the VCU based on the current gear and the current vehicle speed, and the engine target speed sent by the TCU to the VCU is also calculated based on the current gear and the current vehicle speed, it is equivalent to that the engine target speed requested by the TCU is basically consistent with the current actual engine speed. In this way, the conditions for TCU to close the clutch can be basically met without speed regulation, saving the time required for speed regulation, which is conducive to quickly closing the clutch, making the speed of switching from idle pure electric four-wheel drive mode to direct drive mode faster, thereby shortening the engine torque output time and speeding up the torque output speed.

[0151] In an exemplary embodiment, the determination method of the above target idle speed can be summarized as follows:

[0152] When the actual operating mode is not the idle pure electric four-wheel drive mode, the VCU determines the target idle speed of the engine as a pre-calibrated series idle speed.

[0153] When the actual operation mode is the idle pure electric four-wheel drive mode, the target idle speed is determined according to the following three situations:

[0154] Case 1: If the target operation mode is the series mode, the VCU determines the target idle speed of the engine to be a pre-calibrated series idle speed.

[0155] Case 2: If the target operation mode is direct drive mode, the VCU determines the target idle speed as the TCU speed control speed, that is, the VCU determines the engine target speed determined by the TCU based on the current gear and the current vehicle speed as the target idle speed. When the TCU speed is controlled, the TCU calculates the engine target speed based on the current gear and the current vehicle speed, and sends the engine target speed to the VCU, so that the VCU determines the received engine target speed calculated by the TCU as the target idle speed.

[0156] Case 3: If the conditions in Case 1 and Case 2 are not met, that is, the current target operating mode is neither the series mode nor the direct drive mode, but the idle pure electric four-wheel drive mode, then the VCU will reversely infer the engine target speed based on the current gear position and the current vehicle speed as the above-mentioned target idle speed.

[0157] In an exemplary embodiment, the target idle torque carried in the idle load torque signal is determined as follows: if the idle request signal carries the second signal value, the target idle torque is determined to be 0; if the idle request signal carries the first signal value, it is determined whether the vehicle's current target operating mode is the idle pure electric four-wheel drive mode and whether the clutch is in a disengaged state; if so, the target idle torque is determined to be 0; if not, the target idle torque is determined to be a pre-calibrated power generation torque corresponding to the current vehicle condition data.

[0158] If the idle request signal carries the second signal value, it means that the VCU does not request the engine to activate idle, that is, the engine does not need to be in an idle state, and the engine does not need to output idle torque. Therefore, the VCU determines that the target idle torque is 0. In addition, since the VCU does not request the engine to activate idle, it means that after receiving the idle request signal, the ECM will not pay attention to the target idle torque carried in the idle load torque signal.

[0159] If the idle request signal carries the first signal value, it means that the VCU requests the engine to activate the idle speed, that is, the engine needs to be in the idle state, then it can be further determined whether the current target operation mode of the vehicle is the idle pure electric four-wheel drive mode and whether the clutch is in a disengaged state. If the current target operation mode of the vehicle is the idle pure electric four-wheel drive mode and the clutch is in a disengaged state, it means that the vehicle does not need to be charged at present, so the VCU can determine that the target idle torque is 0. If the current target operation mode of the vehicle is not the idle pure electric four-wheel drive mode or the clutch is in a closed state, it means that the vehicle may actually be in the series mode at present. Since in the series mode, the engine runs to drive the front drive motor to generate electricity, therefore, the VCU can determine that the target idle torque is a pre-calibrated power generation torque corresponding to the current vehicle condition data, and the power generation torque is also a negative front drive motor torque. The power generation torque can be pre-calibrated according to the actual required charging demand. For example, if you want to charge quickly, you can calibrate the power generation torque to be larger, and if you want to charge slowly, you can calibrate the power generation torque to be smaller. This embodiment does not make specific restrictions on this.

[0160] In a possible implementation, the correspondence between vehicle condition data and power generation torque can be pre-calibrated, for example, the correspondence between vehicle condition data such as engine target speed and battery pack chargeable power and power generation torque can be calibrated. Therefore, when the power generation torque needs to be determined later, the VCU can determine the power generation torque corresponding to the current vehicle condition data based on the correspondence, so that the determined power generation torque is more suitable for the current vehicle condition data.

[0161] In an exemplary embodiment, the determination method of the target idle torque carried in the idle load torque signal can be summarized as follows:

[0162] When the VCU does not request the engine to activate idle, the VCU sets the target idle torque of the engine to 0.

[0163] When the VCU requests the engine to activate idle, it determines whether the target operating mode is the idle pure electric four-wheel drive mode and whether the clutch is in a disengaged state. If so, the VCU sets the target idle torque to 0, otherwise the VCU sets the target idle torque to the power generation torque (ie, negative front drive motor torque).

[0164] In a possible implementation, the timing diagram of mode switching involved in the control method of this embodiment can be found in Figure 8 .

[0165] like Figure 8 As shown, the mode switching process from the idle pure electric four-wheel drive mode to the series mode includes three stages: the first stage (idle pure electric four-wheel drive mode), the second stage (the process of switching from the idle pure electric four-wheel drive mode to the series mode), and the third stage (series mode). For ease of description, Figure 8 The idle pure electric four-wheel drive mode in some places is abbreviated as idle EAWD. The following are the specific descriptions of these three stages:

[0166] Phase 1: The vehicle is stable in the idling pure electric four-wheel drive mode. Figure 8 As shown, in the first stage, the actual operation mode and target operation mode of the vehicle are both the idle pure electric four-wheel drive mode, the clutch is in a disengaged state, and the engine torque requested by the VCU (the driving torque of the engine mentioned above) is the friction torque, which is a negative value. The idle request signal indicates the activation of the idle state, and the target idle speed carried in the idle speed signal is reversed by the VCU based on the current gear and the current vehicle speed. The target idle torque carried in the idle load torque signal is 0, and the actual engine speed follows the target idle speed.

[0167] The second stage: the process of the vehicle switching from the idle pure electric four-wheel drive mode to the series mode. Figure 8As shown in the figure, in the second stage, the remaining power of the vehicle is less than the preset power threshold (13%), the target operation mode is the series mode, the actual operation mode is the idle pure electric four-wheel drive mode, the clutch is in the disengaged state, and the idle request signal indicates the activation of the idle state, which is different from the Figure 6 The idle request signal shown indicates that the idle state is not activated. The second stage can be further divided into: a torque reduction stage, a gear removal stage and a speed regulation stage.

[0168] In the torque reduction phase, the front drive motor torque requested by the VCU is reduced (not shown in the figure). Since the engine idle state is activated in this phase, the engine torque requested by the VCU is the friction torque, and the target idle torque carried in the idle load torque signal is 0.

[0169] During the gear shifting stage, when the front-wheel drive motor torque requested by the VCU is reduced to near 0, the TCU executes the gear shifting and switches the current gear from 1st gear in the idle pure electric four-wheel drive mode to N gear to meet the gear requirements of the series mode.

[0170] Speed ​​regulation stage: synchronize the front drive motor and engine speed and control the clutch closing. Figure 8 It can be seen that during the speed regulation phase, the actual engine speed stably follows the target idle speed carried in the idle speed signal, showing an upward trend, and the actual engine speed does not fluctuate. The engine torque requested by the VCU is also stable at the friction torque, without fluctuations.

[0171] Stage 3: The vehicle is stable in series mode. Figure 8 As shown, in the third stage, the remaining power of the vehicle is less than the preset power threshold (13%), the target operation mode and the actual operation mode are both series mode, the clutch is in a closed state, the idle request signal indicates the activated idle state, the target idle speed carried in the idle speed signal is the series idle speed, the target idle torque carried in the idle load torque signal is the power generation torque, the engine torque requested by the VCU is the friction torque, and the actual engine speed is still following the target idle speed. Since the engine is actually still in the idle state in the third stage, the series mode of the third stage is actually the above-mentioned series idle mode (first type series mode). In a specific implementation, if the engine exits the idle state in the third stage, then the series mode of the third stage belongs to the stable series mode (second type series mode).

[0172] By comparison Figure 6 and Figure 8 It can be seen that the process of the vehicle switching from the idle pure electric four-wheel drive mode to the series mode, Figure 8During the mode switching process, the idle request signal still indicates the activated idle state, the target idle torque carried in the idle load torque signal is 0, and the engine torque requested by the VCU is still the friction torque, and there will be no torque fluctuation. The actual engine speed still stably follows the target idle speed, and there will be no fluctuations, which is beneficial to improving the driver's driving experience during driving.

[0173] Fig. 9 It is a structural schematic diagram of a vehicle control device provided in an embodiment of the present application.

[0174] For example, Fig. 9 As shown, the device 900 includes: a judgment module 901, which is used to judge whether the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met when the vehicle is currently in the idle pure electric four-wheel drive mode; a sending module 902, which is used to keep sending an idle request signal carrying a first signal value to the engine controller during the mode switching process if the switching conditions are met; wherein, in the idle pure electric four-wheel drive mode, the front drive motor and the rear drive motor of the vehicle are in a driving state, the engine is in an idle state, and the clutch is in a disengaged state; in the series mode, the rear drive motor is in a driving state, the engine runs to drive the front drive motor to generate electricity, and the clutch is in a closed state; the first signal value is used to instruct the engine controller to activate the idle state of the engine.

[0175] In a possible implementation, the series mode is a first type of series mode or a second type of series mode. In the first type of series mode, the engine is in an idle state, and in the second type of series mode, the engine is in a non-idle state; the sending module 902 is also used for: if it is detected that the vehicle has switched from the idle pure electric four-wheel drive mode to the first type of series mode, then continue to send an idle request signal carrying the first signal value to the engine controller; if it is detected that the vehicle has switched from the idle pure electric four-wheel drive mode to the second type of series mode, then send an idle request signal carrying a second signal value to the engine controller; wherein the second signal value is used to instruct the engine controller not to activate the idle state of the engine.

[0176] In a possible implementation, the sending module 902 is also used to: when the vehicle has switched from the idle pure electric four-wheel drive mode to the first type of series mode, send the target idle speed to the engine controller, so that the engine controller controls the idle speed of the engine according to the target idle speed; when the vehicle has switched from the idle pure electric four-wheel drive mode to the second type of series mode, request the engine to output a pre-calibrated power generation torque corresponding to the current vehicle condition data.

[0177] In a possible implementation, the judgment module 901 is specifically used to: obtain the current remaining power, current gear, current energy mode and driving mode of the vehicle; if the remaining power of the vehicle is less than a preset power threshold, it is determined that the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met; if the combination of the current energy mode and the driving mode meets the preset combination conditions, and the current gear is P gear, it is determined that the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met; wherein the preset combination conditions include: the current energy mode is a pure electric priority mode or a hybrid mode, and the driving mode is an AWD mode, a snow mode, a mud mode or a sand mode.

[0178] In a possible implementation, the sending module 902 is also used to send an idle request signal, an idle speed signal and an idle load torque signal to the engine controller when the vehicle is detected to be started, so that the engine controller can activate the idle state of the engine based on a first signal value carried in the idle request signal, or not activate the idle state of the engine based on a second signal value carried in the idle request signal, and instruct the engine controller to control the idle speed of the engine based on the target idle speed carried in the idle speed signal when the idle state of the engine is activated, and to control the idle torque of the engine based on the target idle torque carried in the idle load torque signal.

[0179] In a possible implementation, the above-mentioned device also includes a signal value determination module, which is used to determine that the idle request signal carries the first signal value when the preset idle activation condition is met; when the preset idle activation condition is not met, determine that the idle request signal carries the second signal value; wherein the idle activation condition includes: a first preset condition, a second preset condition or a third preset condition; the first preset condition includes: the target operating mode is the idle pure electric four-wheel drive mode; the second preset condition includes: the actual operating mode is the idle pure electric four-wheel drive mode, the target operating mode is the series mode and the clutch is in a disengaged state; the third preset condition includes: the battery pack temperature of the vehicle is lower than the first temperature threshold, or the coolant temperature of the engine is lower than the second temperature threshold.

[0180] In a possible implementation, the above-mentioned device also includes: a determination module, which is used to determine that the target operation mode is the idle pure electric four-wheel drive mode if the following conditions are met: the current remaining power of the vehicle is greater than the preset power threshold; and the current speed of the vehicle is less than or equal to the preset speed threshold; and the current gear of the vehicle is not P gear; and, when the current energy mode of the vehicle is pure electric priority mode or hybrid mode, the driving mode is AWD mode, snow mode, mud mode or sand mode.

[0181] In a possible implementation, the above-mentioned device also includes: a target idle speed determination module, which is used to determine the current target operation mode of the vehicle when the actual operation mode of the vehicle is the idle pure electric four-wheel drive mode, and determine the target idle speed of the engine based on the current target operation mode; when the actual operation mode of the vehicle is not the idle pure electric four-wheel drive mode, the pre-calibrated series idle speed is determined as the target idle speed; wherein, the series idle speed is used to make the engine idle in the series mode to drive the front drive motor to generate electricity.

[0182] In a possible implementation, the target idle speed determination module is specifically used to: if the current target operation mode is the series mode, then the series idle speed is determined as the target idle speed; if the current target operation mode is the direct drive mode, then the engine target speed received from the TCU is determined as the target idle speed; wherein, the engine target speed sent by the TCU is calculated by the TCU based on the current gear position and the current vehicle speed; if the current target operation mode is the idle pure electric four-wheel drive mode, then the engine target speed calculated by the VCU based on the current gear position and the current vehicle speed is determined as the target idle speed.

[0183] In a possible implementation, the above-mentioned device also includes: a target idle torque determination module, which is used to determine that the target idle torque is 0 if the idle request signal carries the second signal value; if the idle request signal carries the first signal value, it is judged whether the current target operation mode of the vehicle is the idle pure electric four-wheel drive mode and whether the clutch is in a disengaged state; if so, it is determined that the target idle torque is 0; if not, it is determined that the target idle torque is a pre-calibrated power generation torque corresponding to the current vehicle condition data.

[0184] Fig.10 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application.

[0185] For example, Fig.10As shown, the vehicle 1000 includes: a memory 1001 and a processor 1002, wherein the memory 1001 stores an executable program code 10011, and the processor 1002 is used to call and execute the executable program code 10011 to perform a vehicle control method.

[0186] In addition, an embodiment of the present application also protects a device, which may include a memory and a processor, wherein the memory stores an executable program code, and the processor is used to call and execute the executable program code to execute a vehicle control method provided by an embodiment of the present application.

[0187] In this embodiment, the functional modules of the device can be divided according to the above method example. For example, each functional module can be corresponded, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0188] In the case of dividing each functional module according to each function, the device may further include a determination module, a sending module, etc. It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0189] It should be understood that the device provided in this embodiment is used to execute the above-mentioned vehicle control method, and thus can achieve the same effect as the above-mentioned implementation method.

[0190] In the case of an integrated unit, the device may include a processing module and a storage module. When the device is applied to a vehicle, the processing module may be used to control and manage the actions of the vehicle. The storage module may be used to support the vehicle in executing related program codes, etc.

[0191] The processing module may be a processor or a controller, which may implement or execute various exemplary logic blocks, modules and circuits shown in combination with the contents disclosed in this application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory.

[0192] In addition, the device provided in the embodiments of the present application may specifically be a chip, a component or a module, and the chip may include a connected processor and a memory; wherein the memory is used to store instructions, and when the processor calls and executes the instructions, the chip can execute a vehicle control method provided in the above embodiments.

[0193] This embodiment also provides a computer-readable storage medium, in which a computer program code is stored. When the computer program code is run on a computer, the computer executes the above-mentioned related method steps to implement a vehicle control method provided by the above embodiment.

[0194] This embodiment also provides a computer program product. When the computer program product is run on a computer, the computer is caused to execute the above-mentioned related steps to implement a vehicle control method provided by the above-mentioned embodiment.

[0195] Among them, the device, computer-readable storage medium, computer program product or chip provided in this embodiment is used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be repeated here.

[0196] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0197] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0198] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A vehicle control method, characterized in that: The method comprises: When the vehicle is currently in an idling pure electric four-wheel drive mode, determining whether a switching condition for switching from the idling pure electric four-wheel drive mode to the series mode is met; If the switching condition is met, the idle request signal carrying the first signal value is kept sent to the engine controller during the mode switching process; wherein, when it is determined that the switching condition is met, if it is detected that the battery pack temperature of the vehicle is lower than the first temperature threshold, or the coolant temperature of the engine is lower than the second temperature threshold, then it is determined that the series mode switched from the idle pure electric four-wheel drive mode is the first type of series mode, and if it is detected that the battery pack temperature is greater than or equal to the first temperature threshold and the coolant temperature of the engine is greater than or equal to the second temperature threshold, then it is determined that the series mode switched from the idle pure electric four-wheel drive mode is the second type of series mode, in which the engine is in an idle state, and in which the engine is in a non-idle state; Wherein, in the idle pure electric four-wheel drive mode, the front drive motor and the rear drive motor of the vehicle are in a driving state, the engine is in an idle state, and the clutch is in a disengaged state; in the series mode, the rear drive motor is in a driving state, the engine runs to drive the front drive motor to generate electricity, and the clutch is in a closed state; the first signal value is used to instruct the engine controller to activate the idle state of the engine; wherein, when the vehicle is detected to be started, an idle speed signal is sent to the engine controller to instruct the engine controller to control the idle speed of the engine based on the target idle speed carried in the idle speed signal when the idle state of the engine is activated; The target idle speed carried in the idle speed signal is determined by: When the actual operation mode of the vehicle is the idle pure electric four-wheel drive mode, determining a current target operation mode of the vehicle; If the current target operation mode is the direct drive mode, the target engine speed sent by the received TCU is determined as the target idle speed; wherein the target engine speed sent by the TCU is calculated by the TCU based on the current gear position and the current vehicle speed; If the current target operating mode is the idle pure electric four-wheel drive mode, the engine target speed calculated by the VCU based on the current gear position and the current vehicle speed is determined as the target idle speed.

2. The method according to claim 1, characterized in that After the idle request signal carrying the first signal value is continuously sent to the engine controller during the mode switching process, the method further includes: If it is detected that the vehicle has switched from the idle pure electric four-wheel drive mode to the first type of series mode, continue to send an idle request signal carrying the first signal value to the engine controller; If it is detected that the vehicle has switched from the idle pure electric four-wheel drive mode to the second type of series mode, an idle request signal carrying a second signal value is sent to the engine controller; wherein the second signal value is used to instruct the engine controller not to activate the idle state of the engine.

3. The method according to claim 2, characterized in that The method further comprises: When the vehicle has switched from the idle pure electric four-wheel drive mode to the first type of series mode, sending a target idle speed to the engine controller so that the engine controller controls the idle speed of the engine according to the target idle speed; When the vehicle has switched from the idle pure electric four-wheel drive mode to the second type series mode, the engine is requested to output a pre-calibrated power generation torque corresponding to the current vehicle condition data.

4. The method according to claim 1, characterized in that: The determining whether the switching condition for switching from the idle pure electric four-wheel drive mode to the series mode is met includes: Obtaining the current remaining power, current gear, current energy mode and driving mode of the vehicle; If the remaining power of the vehicle is less than the preset power threshold, it is determined that the switching condition from the idle pure electric four-wheel drive mode to the series mode is met; If the combination of the current energy mode and driving mode meets the preset combination conditions, and the current gear is P gear, it is determined that the switching conditions for switching from the idle pure electric four-wheel drive mode to the series mode are met; wherein the preset combination conditions include: the current energy mode is pure electric priority mode or hybrid mode, and the driving mode is four-wheel drive mode, snow mode, mud mode or sand mode.

5. The method according to claim 1, characterized in that The method further comprises: When vehicle start is detected, an idle request signal and an idle load torque signal are sent to an engine controller, so that the engine controller activates the idle state of the engine based on a first signal value carried in the idle request signal, or does not activate the idle state of the engine based on a second signal value carried in the idle request signal, and instructs the engine controller to control the idle torque of the engine based on the target idle torque carried in the idle load torque signal when the idle state of the engine is activated.

6. The method according to claim 5, characterized in that The first signal value or the second signal value carried in the idle request signal is determined by: When a preset idle activation condition is met, determining that the idle request signal carries the first signal value; In a case where a preset idle activation condition is not met, determining that the idle request signal carries the second signal value; Wherein, the idle activation condition includes: a first preset condition, a second preset condition or a third preset condition; The first preset condition includes: the target operation mode of the vehicle is the idle pure electric four-wheel drive mode; The second preset condition includes: the actual operation mode of the vehicle is the idle pure electric four-wheel drive mode, the target operation mode is the series mode, and the clutch is in a disengaged state; The third preset condition includes: the battery pack temperature of the vehicle is lower than a first temperature threshold, or the coolant temperature of the engine is lower than a second temperature threshold.

7. The method according to claim 6, characterized in that If the following conditions are met, the target operation mode is determined to be the idle pure electric four-wheel drive mode: The current remaining power of the vehicle is greater than a preset power threshold; and The current speed of the vehicle is less than or equal to a preset speed threshold; and The current gear position of the vehicle is not P gear; and, When the current energy mode of the vehicle is the pure electric priority mode or the hybrid mode, the current driving mode of the vehicle is the four-wheel drive mode, the snow mode, the mud mode or the sand mode.

8. The method according to claim 1, characterized in that The target idle speed carried in the idle speed signal is also determined in the following manner: When the actual operating mode of the vehicle is not the idle pure electric four-wheel drive mode, the pre-calibrated series idle speed is determined as the target idle speed; wherein the series idle speed is used to make the engine idle in the series mode to drive the front drive motor to generate electricity.

9. The method according to claim 1, characterized in that: When the actual operation mode of the vehicle is the idle pure electric four-wheel drive mode, after determining the current target operation mode of the vehicle, the method further includes: If the current target operating mode is the series mode, the pre-calibrated series idle speed is determined as the target idle speed; wherein the series idle speed is used to make the engine idle in the series mode to drive the front drive motor to generate electricity.

10. The method according to claim 5, characterized in that The target idle torque carried in the idle load torque signal is determined in the following manner: If the idle request signal carries the second signal value, determining the target idle torque to be 0; If the idle request signal carries the first signal value, determining whether the current target operation mode of the vehicle is the idle pure electric four-wheel drive mode and whether the clutch is in a disengaged state; If so, the target idle torque is determined to be 0; if not, the target idle torque is determined to be a pre-calibrated power generation torque corresponding to the current vehicle condition data.

11. A vehicle control device, characterized in that: The device comprises: A judgment module, used for judging whether a switching condition for switching from the idle pure electric four-wheel drive mode to the series mode is met when the vehicle is currently in the idle pure electric four-wheel drive mode; A sending module, for maintaining sending an idle request signal carrying a first signal value to an engine controller during a mode switching process if the switching condition is met; wherein, when it is determined that the switching condition is met, if it is detected that the battery pack temperature of the vehicle is lower than a first temperature threshold, or the coolant temperature of the engine is lower than a second temperature threshold, then it is determined that the series mode switched from the idle pure electric four-wheel drive mode is a first type of series mode, and if it is detected that the battery pack temperature is greater than or equal to the first temperature threshold and the coolant temperature of the engine is greater than or equal to the second temperature threshold, then it is determined that the series mode switched from the idle pure electric four-wheel drive mode is a second type of series mode, in which the engine is in an idle state, and in which the engine is in a non-idle state; Wherein, in the idle pure electric four-wheel drive mode, the front drive motor and the rear drive motor of the vehicle are in a driving state, the engine is in an idle state, and the clutch is in a disengaged state; in the series mode, the rear drive motor is in a driving state, the engine runs to drive the front drive motor to generate electricity, and the clutch is in a closed state; the first signal value is used to instruct the engine controller to activate the idle state of the engine; wherein, when the vehicle is detected to be started, an idle speed signal is sent to the engine controller to instruct the engine controller to control the idle speed of the engine based on the target idle speed carried in the idle speed signal when the idle state of the engine is activated; The target idle speed carried in the idle speed signal is determined by: When the actual operation mode of the vehicle is the idle pure electric four-wheel drive mode, determining a current target operation mode of the vehicle; If the current target operation mode is the direct drive mode, the target engine speed sent by the received TCU is determined as the target idle speed; wherein the target engine speed sent by the TCU is calculated by the TCU based on the current gear position and the current vehicle speed; If the current target operating mode is the idle pure electric four-wheel drive mode, the engine target speed calculated by the VCU based on the current gear position and the current vehicle speed is determined as the target idle speed.

12. A vehicle, characterized in that: The vehicle comprises: A memory for storing executable program codes; A processor, configured to call and run the executable program code from the memory, so that the vehicle executes the method according to any one of claims 1 to 10.

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

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