Starting Method and Device for Engine in Dual-Motor Hybrid Power System and Vehicle

Abstract

The present invention provides a method and apparatus for starting an engine in a dual-motor hybrid power system and a vehicle, belonging to the technical field of vehicles. The dual-motor hybrid power system includes an engine, a first motor connected to the engine, and a clutch connected between the first motor and a transmission system. The starting method includes: when receiving an engine starting request, acquiring current state data of the vehicle, where the current state data of the vehicle includes the coolant temperature of the engine; judging the starting mode intended by the driver according to the current state data of the vehicle; determining the fuel injection time of the engine corresponding to a target component for dragging the engine to start according to the coolant temperature of the engine and the starting mode intended by the driver, wherein the target component is the first motor or the clutch; and controlling the engine to inject fuel at the determined fuel injection time during the process of the target component dragging the engine to start. The present invention can improve the smoothness and safety of engine starting.

Description

[0001] This application is a divisional application of a Chinese invention application with an application number of 202110018887.7, an application date of January 7, 2021, and an invention title of "Starting Method and Device for Engine in Dual-Motor Hybrid Power System and Vehicle". Technical Field

[0002] The present invention relates to the technical field of vehicles, and in particular to a starting method and device for an engine in a dual-motor hybrid power system and a hybrid vehicle. Background Art

[0003] With the increasingly strict requirements of various countries for vehicle fuel consumption and emissions and the development of the electrification system, hybrid power technology has become the key to achieving energy conservation and emission reduction in vehicles. Due to the complex battery technology and high cost of the current pure electric system, the hybrid power system has been vigorously promoted. The dual-motor hybrid power system is a high-efficiency hybrid power system, and its general structure is as Figure 1 shown. The dual-motor hybrid power system generally has three engine starting methods: starting the engine by a 12V starter (abbreviated as 12V starting), starting the engine by a P1 motor (abbreviated as P1 motor starting), and starting the engine by a clutch C0 (abbreviated as clutch starting). Under normal circumstances, the dual-motor hybrid power system uses the P1 motor to start. In the case of a failure of the P1 motor, 12V starting or clutch starting is selected according to the vehicle speed. However, in the prior art, during the P1 motor starting or clutch starting process, the engine usually starts fuel injection before the driving torque of the P1 motor or the clutch has not been unloaded completely, resulting in starting shock; and during cold start, due to the long setting time of the engine's delayed fuel injection, starting failure or engine speed drop pits occur, which seriously affect the smoothness and safety of engine starting. Therefore, there is an urgent need for a starting method that can improve the smoothness and safety of engine starting in a dual-motor hybrid power system. Summary of the Invention

[0004] In view of the above problems, the present invention is proposed to provide a starting method and device for an engine in a dual-motor hybrid power system and a hybrid vehicle that can overcome the above problems or at least partially solve the above problems.

[0005] An object of the present invention is to provide a starting method for an engine in a dual-motor hybrid power system, which can improve the smoothness and safety of engine starting during P1 motor starting or clutch starting.

[0006] A further object of the present invention is to prevent motor jitter during clutch starting and further improve starting smoothness.

[0007] In particular, according to one aspect of the embodiments of the present invention, a method for starting an engine in a dual-motor hybrid power system is provided. The dual-motor hybrid power system includes an engine, a first motor connected to the engine, and a clutch connected between the first motor and a transmission system. The starting method includes:

[0008] When receiving an engine start request, obtain the current state data of the vehicle, where the current state data of the vehicle includes the coolant temperature of the engine;

[0009] Judge the starting mode of the driver's intention according to the current state data of the vehicle;

[0010] Determine the fuel injection time of the engine corresponding to the target component to be used to start the engine according to the coolant temperature of the engine and the starting mode of the driver's intention, where the target component is the first motor or the clutch;

[0011] During the process of starting the engine by the target component, control the engine to inject fuel at the determined fuel injection time.

[0012] Optionally, the current state data further includes the throttle state or the driver's requested torque;

[0013] The starting mode of the driver's intention includes a quick start mode and a smooth start mode.

[0014] Optionally, the throttle state includes the throttle opening and the throttle change rate;

[0015] The step of judging the starting mode of the driver's intention according to the current state data of the vehicle includes:

[0016] Judge whether the throttle opening is greater than a first throttle opening threshold and the throttle change rate is greater than a preset change rate threshold;

[0017] If so, determine that the starting mode of the driver's intention is the quick start mode;

[0018] If not, determine that the starting mode of the driver's intention is the smooth start mode; or,

[0019] Judge whether the driver's requested torque is greater than a first wheel-end torque threshold;

[0020] If so, determine that the starting mode of the driver's intention is the quick start mode;

[0021] If not, determine that the starting mode of the driver's intention is the smooth start mode.

[0022] Optionally, the step of determining the fuel injection time of the engine corresponding to the target component for dragging the engine to start according to the coolant temperature of the engine and the driver's intention includes:

[0023] When the start mode intended by the driver is the quick start mode, determine that the fuel injection time of the engine is the time when the engine speed is greater than 0;

[0024] When the start mode intended by the driver is the smooth start mode and the coolant temperature of the engine is greater than the preset warm engine start temperature, determine that the fuel injection time of the engine is the time when the dragging torque of the target component is completely unloaded;

[0025] When the start mode intended by the driver is the smooth start mode and the coolant temperature of the engine is less than or equal to the preset warm engine start temperature, look up the correspondence table between the coolant temperature of the engine and the torque limit value of the target component, obtain the target torque limit value of the target component corresponding to the coolant temperature of the engine, and determine that the fuel injection time of the engine is the time when the dragging torque of the target component is less than the target torque limit value.

[0026] Optionally, the correspondence table includes a first correspondence table between the coolant temperature of the engine and the torque limit value of the first motor and a second correspondence table between the coolant temperature of the engine and the torque limit value of the clutch; wherein,

[0027] In the first correspondence table, the coolant temperature of the engine is inversely proportional to the torque limit value of the first motor;

[0028] In the second correspondence table, the coolant temperature of the engine is inversely proportional to the torque limit value of the clutch.

[0029] Optionally, the step of controlling the engine to inject fuel at the determined fuel injection time during the process of the target component dragging the engine to start includes:

[0030] When the start mode intended by the driver is the quick start mode, obtain the current speed of the engine in real time during the process of the target component dragging the engine to start;

[0031] When the current speed of the engine is greater than 0, control the engine to inject fuel;

[0032] When the start mode intended by the driver is the smooth start mode, obtain the dragging torque of the target component in real time during the process of the target component dragging the engine to start;

[0033] When the coolant temperature of the engine is greater than the preset warm engine start temperature and the drag torque of the target component is completely unloaded, control the engine to inject fuel.

[0034] When the coolant temperature of the engine is less than or equal to the preset warm engine start temperature and the drag torque of the target component is less than the target torque limit, control the engine to inject fuel.

[0035] Optionally, the dual-motor hybrid power system further includes a second motor connected to the transmission system and used to drive the wheels.

[0036] The starting method further includes:

[0037] When the target component is the clutch, during the process of the clutch dragging the engine to start, perform active damping control on the second motor.

[0038] Optionally, the step of performing active damping control on the second motor includes:

[0039] Obtain the requested speed of the driver and the actual speed of the second motor;

[0040] Calculate the difference between the requested speed and the actual speed;

[0041] Perform proportional-integral control on the second motor according to the difference to compensate the output torque of the second motor.

[0042] According to another aspect of the embodiments of the present invention, there is also provided a starting device for an engine in a dual-motor hybrid power system, including a memory and a processor. A control program is stored in the memory, and when the control program is executed by the processor, it is used to implement the starting method described in any one of the foregoing.

[0043] According to still another aspect of the embodiments of the present invention, there is also provided a hybrid vehicle, including a dual-motor hybrid power system and the starting device for an engine in the dual-motor hybrid power system described above.

[0044] In the starting method and device for an engine in the dual-motor hybrid power system proposed by the embodiments of the present invention, the starting mode intended by the driver can be determined according to the current state data of the vehicle, and then the fuel injection time of the engine corresponding to the target component (the first motor, i.e., the P1 motor, or the clutch) can be determined according to the coolant temperature of the engine and the starting mode intended by the driver. Thus, the time when the engine starts to inject fuel can be specifically controlled during the starting process of the P1 motor or the clutch, preventing phenomena such as starting shock, starting failure, or engine speed drop caused by premature or overly delayed fuel injection of the engine, and improving the smoothness and safety of engine starting.

[0045] Further, for the quick start mode, the fuel injection time of the engine is the time when the engine speed is greater than 0, that is to say, the engine does not delay fuel injection, thus ensuring the response speed of quick start. For the smooth start mode and the case where the coolant temperature of the engine is greater than the preset warm engine start temperature (i.e., warm engine start), the fuel injection time of the engine is the time when the driving torque of the first motor or the clutch is completely unloaded, that is to say, the engine delays fuel injection until the driving torque is completely unloaded, which can avoid the disturbance impact caused by the incomplete unloading of the torque of the first motor or the clutch and improve the start smoothness. For the smooth start mode and the case where the coolant temperature of the engine is less than or equal to the preset warm engine start temperature (i.e., cold engine start), the fuel injection time of the engine is the time when the driving torque of the first motor or the clutch is less than the target torque limit value. Since the engine does not need to wait for the complete unloading of the driving torque to inject fuel at this time, but can start fuel injection when the driving torque of the first motor or the clutch is less than the corresponding target torque limit value, it prevents the engine speed from dropping or the start from failing.

[0046] Further, during the process of starting the engine by the clutch (i.e., clutch start), by performing active damping control on the second motor (i.e., the drive motor), the jitter of the second motor during the clutch start process can be prevented, and the start smoothness can be further improved.

[0047] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the description. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are specifically exemplified below.

[0048] According to the following detailed description of the specific embodiments of the present invention in conjunction with the drawings, those skilled in the art will understand the above and other purposes, advantages and features of the present invention more clearly. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. And throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0050] Figure 1 is a schematic structural diagram of a dual-motor hybrid power system;

[0051] Figure 2 is Figure 1 a schematic diagram of the dual-motor hybrid power system shown during clutch start;

[0052] Figure 3Schematic flow chart of the engine starting method in the dual-motor hybrid power system according to Embodiment 1 of the present invention;

[0053] Figure 4 Schematic flow chart of the engine starting method in the dual-motor hybrid power system according to Embodiment 2 of the present invention;

[0054] Figure 5 Schematic diagram of the starting effect when the pre-dragging torque is adopted during the starting of the P1 motor in the engine starting method of the dual-motor hybrid power system according to Embodiment 2 of the present invention;

[0055] Figure 6 Schematic diagram of the starting effect when the pre-dragging torque is not adopted during the starting of the P1 motor in the prior art;

[0056] Figure 7 Schematic diagrams of each stage during the starting of the P1 motor in Embodiment 2 of the present invention;

[0057] Figure 8 Schematic flow chart of the engine starting method in the dual-motor hybrid power system according to Embodiment 3 of the present invention;

[0058] Figure 9 Schematic structural diagram of the engine starting device in the dual-motor hybrid power system according to an embodiment of the present invention. Detailed implementation manners

[0059] Hereinafter, the exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be completely conveyed to those skilled in the art.

[0060] The dual-motor hybrid power system is a key technology for realizing vehicle energy conservation and emission reduction at present. As Figure 1 shown, the dual-motor hybrid power system generally may include an engine 1, a first motor 2 connected to the engine 1 ( Figure 1 labeled as P1 in Figure 1 ), and a clutch 3 ( Figure 1 labeled as C0 in

[0061] A dual-motor hybrid power system generally has three modes: pure electric mode, series mode, and parallel mode. In the series mode, the clutch C0 is not engaged, and the engine 1 charges the battery 4 through the first motor 2 (i.e., the P1 motor), and the battery 4 supplies electric energy to the second motor 7 (i.e., the P2 motor) to enable the P2 motor to drive the wheels 6. In the parallel mode, the clutch C0 is engaged, and the engine 1 and the P2 motor directly drive the wheels 6 simultaneously.

[0062] As described above, a dual-motor hybrid power system generally has three engine starting methods: starting the engine 1 by a 12V starter (abbreviated as 12V starting, and the 12V starter is not shown in Figure 1 ), starting the engine 1 by the P1 motor (abbreviated as P1 motor starting), and starting the engine 1 by the clutch C0 (abbreviated as clutch starting). Normally, the dual-motor hybrid power system uses P1 motor starting, and in the case of a failure of the P1 motor, 12V starting or clutch starting is selected according to the current vehicle speed. When starting with the clutch, as Figure 2 shown, the clutch C0 is engaged, and the engine 1 is started by dragging through the clutch C0, Figure 2 and the black arrow in

[0063] represents the transmission direction of the dragging torque.

[0064] However, in the prior art, during the starting process of the P1 motor or the clutch starting, the engine 1 starts fuel injection before the dragging torque of the P1 motor or the clutch C0 is completely unloaded, resulting in starting shock, or the engine 1 delays fuel injection during cold start, resulting in starting failure or a drop in the engine 1 speed, with poor smoothness and safety.

[0064] To solve or at least partially solve the above technical problems, an embodiment of the present invention proposes a method for starting an engine in a dual-motor hybrid power system. The technical solutions in the embodiments of the present invention will be clearly and completely described below through Embodiment 1 to Embodiment 4 of the present invention.

[0065] Embodiment 1

[0066] In this embodiment, the structure of the dual-motor hybrid power system is as Figure 1 shown, including an engine 1, a first motor 2 (i.e., the P1 motor) connected to the engine 1, and a clutch 3 (i.e., the clutch C0) connected between the first motor 2 and the transmission system 5.

[0067] Referring to Figure 3 shown, the method for starting the engine in the dual-motor hybrid power system of this embodiment may at least include the following steps S302 to S308.

[0068] Step S302: When receiving an engine start request, obtain the current state data of the vehicle. The current state data of the vehicle includes the coolant temperature of Engine 1 (usually the cooling water temperature of Engine 1).

[0069] Step S304: Determine the start mode of the driver's intention according to the current state data of the vehicle.

[0070] Step S306: Determine the fuel injection time of Engine 1 corresponding to the target component for starting Engine 1 to be dragged according to the coolant temperature of Engine 1 and the start mode of the driver's intention. Wherein, the target component is the first motor 2 (i.e., the P1 motor) or the clutch 3 (i.e., the clutch C0).

[0071] Step S308: Control Engine 1 to inject fuel at the determined fuel injection time during the process of the target component dragging Engine 1 to start.

[0072] In the engine start method of the dual-motor hybrid power system proposed in the embodiment of the present invention, the start mode of the driver's intention can be judged according to the current state data of the vehicle, and then the fuel injection time of Engine 1 corresponding to the target component (the first motor 2, i.e., the P1 motor, or the clutch C0) can be determined according to the coolant temperature of Engine 1 and the start mode of the driver's intention, so that the time when Engine 1 starts to inject fuel can be controlled specifically during the start process of the P1 motor or the clutch, preventing phenomena such as start shock, start failure, or engine speed drop caused by Engine 1 injecting fuel too early or too late, and improving the smoothness and safety of Engine 1 starting.

[0073] Of course, in practical applications, when receiving an engine start request, the current state of the P1 motor, or the current state of the P1 motor and the current vehicle speed of the vehicle can also be obtained first, so as to judge whether the target component for starting Engine 1 to be dragged is the P1 motor or the clutch C0 accordingly. If the target component is the P1 motor or the clutch C0, it can be considered that the fuel injection control strategy (specifically controlling the fuel injection time) can be enabled, and then the current state data of the vehicle is obtained, and the start mode of the driver's intention is judged according to the current state data of the vehicle. Specifically, if the current state of the P1 motor is normal, it can be judged that the target component is the P1 motor. If the current state of the P1 motor is faulty and the current vehicle speed is greater than the preset vehicle speed threshold (such as 10 km / h), it can be judged that the target component is the clutch C0. Of course, the current vehicle speed of the vehicle can also be used as one of the current state data of the vehicle. When receiving an engine start request, the required current state data of the vehicle is obtained. After judging that the target component is the P1 motor or the clutch C0 and determining that the fuel injection control strategy can be enabled, the subsequent steps S304 to S308 are executed.

[0074] In the above step S302, the current state data of the vehicle may further include the throttle state or the driver's requested torque. Further, the throttle state may include the throttle opening and the throttle change rate.

[0075] Correspondingly, the starting modes of the driver's intention in step S304 may include a rapid start mode and a smooth start mode. Specifically, the step of determining the starting mode of the driver's intention according to the current state data of the vehicle may be implemented as: determining whether the throttle opening is greater than the first throttle opening threshold and the throttle change rate is greater than the preset change rate threshold; if so, determining that the starting mode of the driver's intention is the rapid start mode; if not (that is, the throttle opening is less than or equal to the first throttle opening threshold, or the throttle change rate is less than or equal to the preset change rate threshold), determining that the starting mode of the driver's intention is the smooth start mode. Alternatively, determining whether the driver's requested torque is greater than the first wheel-end torque threshold; if so, determining that the starting mode of the driver's intention is the rapid start mode; if not, determining that the starting mode of the driver's intention is the smooth start mode.

[0076] In this embodiment, the first throttle opening threshold and the preset change rate threshold may be set to 70% and 300% / s respectively. The first wheel-end torque threshold is related to the current vehicle speed of the vehicle. Thus, the current vehicle speed of the vehicle may also be obtained as one item in the current state data of the vehicle in step S302, and then the first wheel-end torque threshold is determined according to the current vehicle speed of the vehicle. Specifically, according to the current vehicle speed of the vehicle, by looking up the relationship table between the vehicle speed and the wheel-end torque limit value, the wheel-end torque limit value corresponding to the current vehicle speed of the vehicle is obtained as the first wheel-end torque threshold. Table 1 below exemplarily shows the relationship table between the vehicle speed and the wheel-end torque limit value.

[0077] Table 1 Relationship table between vehicle speed and wheel-end torque limit value

[0078] Vehicle speed (km / h) 3 10 20 30 50 100 Wheel end torque limit (N·m) 1500 600 235 200 150 100

[0079] When performing the table lookup, for the current vehicle speed of the vehicle that falls between the vehicle speed points in the relationship table between the vehicle speed and the wheel-end torque limit value, the wheel-end torque limit value corresponding to the current vehicle speed may be calculated by interpolation.

[0080] In a specific implementation manner, the above step S306 may be implemented as follows:

[0081] When the starting mode of the driver's intention is the rapid start mode, determining the fuel injection time of engine 1 as the time when the rotational speed of engine 1 is greater than 0;

[0082] When the starting mode of the driver's intention is the smooth start mode and the coolant temperature of engine 1 is greater than the preset warm engine start temperature, determining the fuel injection time of engine 1 as the time when the drag torque of the target component is completely unloaded;

[0083] When the intended start mode of the driver is the smooth start mode and the coolant temperature of the engine 1 is less than or equal to the preset warm engine start temperature, look up the correspondence table between the coolant temperature of the engine and the torque limit of the target component, obtain the target torque limit of the target component corresponding to the coolant temperature of the engine 1, and determine that the fuel injection time of the engine 1 is the time when the driving torque of the target component is less than the target torque limit.

[0084] Further, the correspondence table includes a first correspondence table between the coolant temperature of the engine and the torque limit of the first motor 2 (i.e., the P1 motor) and a second correspondence table between the coolant temperature of the engine and the torque limit of the clutch 3 (i.e., the clutch C0). In the first correspondence table, the coolant temperature of the engine is inversely proportional to the torque limit of the first motor 2. In the second correspondence table, the coolant temperature of the engine is inversely proportional to the torque limit of the clutch 3. The coolant temperature of the engine and the corresponding torque limits in the above correspondence table are calibrated according to the actual vehicle performance. The torque limits corresponding to each temperature are the critical values when the driving torque of the target component reaches the limit and no fuel injection may cause starting failure or engine speed drop when the coolant temperature of the engine is below the preset warm engine start temperature. The preset warm engine start temperature can be set according to the nature parameters of the actual applied engine 1. Generally, it can be set to 60°C.

[0085] The following Table 2 and Table 3 exemplarily show the first correspondence table between the coolant temperature of the engine and the torque limit of the P1 motor and the second correspondence table between the coolant temperature of the engine and the torque limit of the clutch C0.

[0086] Table 2 First correspondence table between the coolant temperature of the engine and the torque limit of the P1 motor

[0087] Engine coolant temperature (°C) -5 10 25 35 45 60 Torque limit (N·m) 75 65 55 50 45 10

[0088] Table 3 Second correspondence table between the coolant temperature of the engine and the torque limit of the clutch C0

[0089] Engine coolant temperature (°C) -5 10 25 35 45 60 Torque limit (N·m) 75 65 55 50 45 -3

[0090] In a practical application scenario, there is a one-to-one linear relationship between the coolant temperature and the torque limit in the first and second correspondence tables. When looking up the table, for the engine coolant temperature falling between the temperature points in Table 2 or Table 3, the torque limit corresponding to the engine coolant temperature can be calculated by interpolation. In another practical application scenario, the coolant temperature range corresponds to the torque limit in the first and second correspondence tables. For example, the torque limit corresponding to the temperature range less than or equal to -5°C is 75 N·m, and the torque limit corresponding to the temperature range greater than -5°C and less than or equal to 10°C is 65 N·m, and so on. When looking up the table, the torque limit corresponding to the engine coolant temperature is determined according to the temperature range where the engine coolant temperature is located.

[0091] Furthermore, in an implementation scenario, after determining the injection time of Engine 1 under different conditions, step S308 above can be implemented in different cases. Specifically, when the driver's intended start mode is the quick start mode, the current speed of Engine 1 is obtained in real time during the process of the target component dragging Engine 1 to start; when the current speed of Engine 1 is greater than 0, Engine 1 is controlled to inject fuel. When the driver's intended start mode is the smooth start mode, the dragging torque of the target component is obtained in real time during the process of the target component dragging Engine 1 to start; in the case where the coolant temperature of Engine 1 is greater than the preset warm engine start temperature, when the dragging torque of the target component is completely unloaded, Engine 1 is controlled to inject fuel; in the case where the coolant temperature of Engine 1 is less than or equal to the preset warm engine start temperature, when the dragging torque of the target component is less than the target torque limit, Engine 1 is controlled to inject fuel. In this implementation scenario, the standard for the complete unloading of the dragging torque of the target component can be set according to actual application requirements. Usually, when the dragging torque of the target component is less than the preset torque lower limit, it can be considered that the dragging torque of the target component has been completely unloaded. In an example, the preset torque lower limit of the P1 motor can be set to 10 N·m, that is, when the dragging torque of the P1 motor is less than 10 N·m, it can be considered that the dragging torque of the P1 motor has been completely unloaded. The preset torque lower limit of the clutch C0 can be set to -3 N·m, that is, when the dragging torque of the clutch C0 is less than -3 N·m, it can be considered that the dragging torque of the clutch C0 has been completely unloaded.

[0092] In this embodiment, for the quick start mode, the fuel injection time of the engine 1 is the time when the rotational speed of the engine 1 is greater than 0. That is to say, the engine 1 does not delay fuel injection, thus ensuring the response speed of the quick start. For the smooth start mode and the case where the coolant temperature of the engine 1 is greater than the preset warm engine start temperature (i.e., warm engine start), the fuel injection time of the engine 1 is the time when the drag torque of the first motor 2 or the clutch 3 is completely unloaded. That is to say, the engine 1 delays fuel injection until the drag torque is completely unloaded (which may be defined as delayed fuel injection). This can avoid the disturbance impact caused by the incomplete unloading of the torque of the first motor 2 or the clutch 3 and improve the start smoothness. For the smooth start mode and the case where the coolant temperature of the engine 1 is less than or equal to the preset warm engine start temperature (i.e., cold engine start), the fuel injection time of the engine 1 is the time when the drag torque of the first motor 2 or the clutch 3 is less than the target torque limit value. Since the engine 1 does not need to wait for the complete unloading of the drag torque to inject fuel at this time, but can start fuel injection when the drag torque of the first motor 2 or the clutch 3 is less than the corresponding target torque limit value (which may be defined as early fuel injection), it prevents the engine 1 from experiencing a speed drop or starting failure.

[0093] Of course, those skilled in the art should recognize that in this embodiment, step S308 is executed during the process of the target component (P1 motor or clutch C0) dragging the engine 1 to start. Especially in the smooth start mode, whether controlling the engine 1 to delay fuel injection or advance fuel injection, it is executed during the process of the target component dragging the engine 1 to reach the target speed and then unloading the drag torque.

[0094] In addition, as Figure 1 shown, the dual-motor hybrid power system of this embodiment may further include a second motor 7 (i.e., P2 motor) connected to the transmission system 5 and used to drive the wheels 6. Since the second motor 7 drives the wheels 6, the second motor 7 can also be referred to as the drive motor. Since during the clutch start process, in addition to driving the wheels 6, the second motor 7 also needs to compensate for the losses during the clutch start, the second motor 7 may generate jitter, which in turn affects the start smoothness. To prevent the jitter of the second motor 7 during the clutch start process, the engine start method of the dual-motor hybrid power system of this embodiment may further include the following steps: When the target component is the clutch C0, during the process of the clutch C0 dragging the engine 1 to start, active damping control is performed on the second motor 7.

[0095] Specifically, the steps of performing active damping control on the second motor 7 may include:

[0096] Obtain the driver's requested speed and the actual speed of the second motor 7;

[0097] Calculate the difference between the requested speed and the actual speed;

[0098] Perform proportional-integral (PI) control on the second motor 7 according to this difference value to compensate for the output torque of the second motor 7.

[0099] Proportional-integral control is a commonly used control strategy and will not be introduced in detail in this article.

[0100] In this embodiment, by performing active damping control on the second motor 7 during the startup process of the clutch, it is possible to prevent the second motor 7 from jittering during the startup process of the clutch and further improve the startup smoothness.

[0101] Embodiment 2

[0102] The difference between this embodiment and Embodiment 1 is that during the process of the target component (the first motor 2 or the clutch 3) dragging the engine 1 to start, not only the fuel injection time of the engine 1 is specifically controlled, but also a prefill torque strategy is executed on the target component.

[0103] Refer to Figure 4 As shown, the method for starting the engine in the dual-motor hybrid power system of this embodiment can at least include the following steps S402 to step S412.

[0104] Step S402, when receiving an engine start request, obtain the current state data of the vehicle, where the current state data of the vehicle at least includes the engine 1 speed and the coolant temperature of the engine 1 (usually the cooling water temperature of the engine 1).

[0105] Step S404, determine the start mode of the driver's intention according to the current state data of the vehicle.

[0106] Step S406, determine whether the prefill torque application condition is satisfied according to the engine 1 speed and the start mode of the driver's intention. If so, execute step S408.

[0107] Step S408, generate a drag start signal and send it to the target component that is to drag the engine 1 to start, and control the target component to output the corresponding prefill torque within a set time period since receiving the drag start signal, where the target component is the first motor 2 (i.e., the P1 motor) or the clutch 3 (i.e., the clutch C0).

[0108] Step S410, determine the fuel injection time of the engine 1 corresponding to the target component according to the coolant temperature of the engine 1 and the start mode of the driver's intention.

[0109] Step S412, control the engine 1 to inject fuel at the determined fuel injection time during the process of the target component dragging the engine 1 to start.

[0110] In the starting method of the engine in the dual-motor hybrid power system proposed by the embodiments of the present invention, when the pre-dragging torque application condition is satisfied, the target component (P1 motor or clutch C0) can be controlled to output the corresponding pre-dragging torque within a set time period starting from the receipt of the dragging start signal, so that the target component can first drag the engine 1 to a certain speed with the pre-dragging torque before the dragging torque of the target component increases to the maximum to drag the engine 1 to the target speed. In this way, the dragging torque of the target component will not directly rise to the maximum, but first reach an intermediate value (i.e., the value of the pre-dragging torque) and then reach the maximum, which can avoid the impact caused by the too-fast rise of the dragging torque during the starting process, thereby further improving the smoothness of the engine starting.

[0111] In this embodiment, the starting modes of the driver's intention may include a quick start mode and a smooth start mode.

[0112] In the above step S402, the current state data of the vehicle may further include the throttle state or the driver-requested torque. Correspondingly, the pre-dragging torque application condition mentioned in step S406 may include: the engine 1 speed is less than the preset speed threshold and the starting mode of the driver's intention is the smooth start mode, where the starting mode of the driver's intention can be judged according to the throttle state or the driver-requested torque. The preset speed threshold can be set according to the actual vehicle calibration result of the actual parameters of the engine 1. When the engine 1 speed is greater than the preset speed threshold, the pre-dragging torque cannot drag the engine 1. Specifically, the preset speed threshold can be set to 50 rpm, for example.

[0113] In a specific implementation scheme, the throttle state may include the throttle opening and the throttle change rate. In this case, step S404 can be specifically implemented as: judging whether the throttle opening is greater than the first throttle opening threshold and the throttle change rate is greater than the preset change rate threshold; if so, determining that the starting mode of the driver's intention is the quick start mode; if not (that is, the throttle opening is less than or equal to the first throttle opening threshold, or the throttle change rate is less than or equal to the preset change rate threshold), determining that the starting mode of the driver's intention is the smooth start mode. Or, judging whether the driver-requested torque is greater than the first wheel-end torque threshold; if so, determining that the starting mode of the driver's intention is the quick start mode; if not, determining that the starting mode of the driver's intention is the smooth start mode. The definitions of the first throttle opening threshold, the preset change rate threshold, and the first wheel-end torque threshold are as described in Embodiment 1 and will not be repeated.

[0114] Further, in step S406, it is judged whether the obtained engine 1 speed is less than or equal to the preset speed threshold and whether the starting mode of the driver's intention is the smooth start mode. If the engine 1 speed is less than or equal to the preset speed threshold and the starting mode of the driver's intention is the smooth start mode, then step S408 is executed.

[0115] In this embodiment, by accurately determining whether the pre-driving torque application condition is satisfied according to the engine 1 speed, throttle state, or driver-requested torque, the effectiveness of the pre-driving torque in improving ride comfort during the engine 1 startup process can be ensured.

[0116] In the above step S408, the set duration can be in the range of 0.2 - 0.4 s. The pre-driving torque corresponding to different target components can be set according to the in-vehicle calibration results when the vehicle starts. When the target component is the P1 motor, if the value of the pre-driving torque is set too large, it will cause impact, and if it is too small, it will not be able to play a buffering role. Therefore, the pre-driving torque corresponding to the P1 motor can preferably be set to 15 - 30 N·m. When the target component is the clutch C0, the setting of the corresponding pre-driving torque should ensure that the clutch C0 can be engaged, so it can preferably be set to 2 - 4 N·m.

[0117] After applying the pre-driving torque, the driving torque of the target component then rises to the maximum value to drive the engine 1 to reach the target speed, realizing the startup of the engine 1. In this way, it is avoided that the driving torque of the target component directly increases to the maximum, improving ride comfort. The following takes the startup of the P1 motor as an example for illustration. Figure 5 shows the startup effect when the pre-driving torque is adopted during the startup of the P1 motor in the startup method of this embodiment. Figure 6 shows the startup effect when the pre-driving torque is not adopted during the startup of the P1 motor in the prior art. Refer to Figure 5 , starting from the moment when the P1 motor receives the driving startup signal (set as the 0 s moment), the P1 motor outputs the pre-driving torque. At 0.1 s, the pre-driving torque reaches 20 N·m and remains at 20 N·m from 0.1 s to 0.2 s, thereby driving the engine 1 to reach a certain speed. After 0.2 s, the pre-driving torque is gradually unloaded, and at 0.4 s, the pre-driving torque drops to 0. At the same time, after 0.2 s, the driving torque output by the P1 motor increases to the maximum value to drive the engine 1 to reach the target speed. After the engine 1 reaches the target speed, the driving torque of the P1 motor is unloaded. In contrast, Figure 6 the P1 motor in [reference] does not have a pre-driving torque after receiving the driving startup signal, and its driving torque directly increases to the maximum value. Comparing Figure 5 and Figure 6 , Figure 5 the fluctuation range of the vehicle acceleration during the startup process in [reference] is 0.16 m / s 2 , while Figure 6 the fluctuation range of the vehicle acceleration during the startup process in [reference] reaches 0.23 m / s 2 , which is 0.07 m / s larger than the fluctuation range of the acceleration in Figure 5 [reference]. 2, It can be seen that by adopting the starting method of this embodiment, the impact during the starting of the engine 1 can be significantly reduced, and the starting smoothness can be improved.

[0118] In this embodiment, after combining the pre-dragging torque strategy and the fuel injection strategy, the process of starting the engine 1 by the P1 motor or the clutch C0 can be divided into the following four stages: (1) The pre-dragging stage, in which the P1 motor or the clutch C0 outputs a pre-dragging torque to drag the engine 1 to a certain speed; (2) The stage of dragging the engine, in which the P1 motor or the clutch C0 drags the engine 1 to the target speed; (3) The torque unloading stage, in which the dragging torque of the P1 motor or the clutch C0 is unloaded to around the preset torque lower limit value; (4) The engine fuel injection stage, in which the engine 1 starts fuel injection. Figure 7 Exemplarily shows the above four stages during the starting process of the P1 motor in the second embodiment.

[0119] It should be noted that step S410 can be executed after step S404 and before step S412, rather than necessarily following step S408.

[0120] Of course, in practical applications, when receiving an engine start request, the current state of the P1 motor, or the current state of the P1 motor and the current vehicle speed of the vehicle, can also be obtained first, so as to judge whether the target component to start the engine 1 to be dragged is the P1 motor or the clutch C0 accordingly. If the target component is the P1 motor or the clutch C0, then obtain the current state data of the vehicle, and judge the starting mode of the driver's intention based on the current state data of the vehicle, and then judge whether the pre-dragging torque application condition is satisfied. Specifically, if the current state of the P1 motor is normal, it can be judged that the target component is the P1 motor. If the current state of the P1 motor is faulty and the current vehicle speed is greater than the preset vehicle speed threshold (such as 10 km / h), it can be judged that the target component is the clutch C0.

[0121] Embodiment Three

[0122] The difference between this embodiment and Embodiment One is that: before starting the engine 1, it is first judged whether the waiting clutch start strategy can be enabled, so as to achieve that even when there is an engine start request when the P1 motor is faulty and the vehicle speed is less than or equal to the preset vehicle speed threshold, the 12V start is not performed, but the clutch start is performed until the vehicle speed increases to be greater than the preset vehicle speed threshold and meets the vehicle speed condition for clutch start.

[0123] Refer to Figure 8 As shown, the starting method of the engine in the dual-motor hybrid power system of this embodiment can at least include the following steps S802 to step S816.

[0124] Step S802, when receiving an engine start request, obtain the current state of the first motor 2.

[0125] Step S804, if the current state of the first motor 2 is a fault, obtain the current state data of the vehicle. The current state data of the vehicle includes at least the current vehicle speed and the coolant temperature of the engine 1 (usually the cooling water temperature of the engine 1).

[0126] Step S806, determine whether the current vehicle speed is less than or equal to a preset vehicle speed threshold and whether other current state data of the vehicle meets the condition for waiting for the clutch to start. If so, that is, the current vehicle speed is less than or equal to the preset vehicle speed threshold and other current state data of the vehicle meets the condition for waiting for the clutch to start, then execute Step S808.

[0127] Step S808, monitor the vehicle speed in real time.

[0128] Step S810, when the vehicle speed is greater than the preset vehicle speed threshold, generate a drag start signal and send it to the clutch 3 to control the clutch 3 to drag the engine 1 to start.

[0129] Step S812, determine the start mode of the driver's intention according to the current state data of the vehicle.

[0130] Step S814, determine the fuel injection time of the engine 1 corresponding to the clutch 3 according to the coolant temperature of the engine 1 and the start mode of the driver's intention.

[0131] Step S816, during the process of the clutch 3 dragging the engine 1 to start, control the engine 1 to inject fuel at the determined fuel injection time.

[0132] The condition for waiting for the clutch to start in Step S806 may include the condition that the vehicle has an acceleration condition and the condition that the vehicle does not require the engine to always run. When the condition that the vehicle has an acceleration condition is met, it can ensure that the vehicle can reach the vehicle speed required for clutch start in a short time, avoiding too long waiting time and unable to ensure the normal operation of the vehicle. When the condition that the vehicle does not require the engine to always run is met, it can ensure the rationality of the waiting clutch start strategy and ensure the normal operation of the vehicle.

[0133] Specifically, the current state data of the vehicle may further include acceleration or throttle opening (also referred to as accelerator pedal opening) and the drive mode of the vehicle. Accordingly, the condition for the vehicle to have an acceleration requirement includes: the acceleration is positive (that is, the vehicle has a positive acceleration) and greater than a preset acceleration threshold, or the throttle opening is greater than a second throttle opening threshold (indicating that the accelerator pedal is in an activated state). The preset acceleration threshold and the second throttle opening threshold can be set according to actual application requirements. For example, the preset acceleration threshold can be set to 0.4m / s 2, the second throttle opening threshold can be set to 5%. Conditions under which the vehicle does not require the engine to always run include: the driving mode of the vehicle is not equal to the sport mode. Hybrid vehicles generally can have multiple driving modes, such as an energy-saving mode, a normal mode, a sport mode, etc. In the sport mode, the engine is required to always run to meet the high-power requirements of the sport mode. Therefore, the waiting clutch start strategy cannot be enabled in the sport mode.

[0134] Furthermore, the current state data of the vehicle can also include the driver-requested torque. The driver-requested torque refers to the wheel torque requested by the driver. Correspondingly, the waiting clutch start condition can also include: the driver-requested torque is less than the second wheel-end torque threshold. The second wheel-end torque threshold can be set according to actual application requirements. For example, it can be set to 1000 N·m. When the driver-requested torque is low, it indicates that the start response speed required by the user is low. In this case, enabling the waiting clutch enabling strategy can improve the NVH performance and smoothness while minimizing the impact on the user's acceleration driving experience.

[0135] In one embodiment, the current state data of the vehicle can also include the throttle state (specifically the throttle opening and throttle change rate) or the driver-requested torque. In this case, the steps of determining the start mode of the driver's intention based on the current state data of the vehicle are as described above and will not be repeated.

[0136] The execution manners of steps S814 and S816 are also as described above and will not be repeated.

[0137] It should be noted that steps S812 and S814 can also be executed at any time after step S806 and before step S816. For example, steps S812 and S814 can be executed during the real-time monitoring of the vehicle speed and before step S810.

[0138] Of course, if the current state of the first motor 2 obtained in step S802 is normal and it is determined that the first motor 2 is the target component to start the engine 1 to be dragged, the subsequent execution steps are the same as those in the case where the target component is the first motor 2 in the first embodiment and will not be elaborated here.

[0139] This embodiment defines a waiting clutch start strategy after the P1 motor fails. Even when there is an engine start request when the P1 motor fails and the vehicle speed is less than or equal to the preset vehicle speed threshold, a 12V start is not performed. Instead, the clutch start is performed when the vehicle speed increases to be greater than the preset vehicle speed threshold to meet the vehicle speed condition for clutch start, avoiding the noise and oscillation generated during a 12V start and improving the NVH performance and smoothness of the engine start.

[0140] Embodiment Four

[0141] The difference between this embodiment and the second embodiment is that before starting the engine 1 using the pre-drag torque strategy, it is first determined whether the waiting clutch start strategy can be enabled. Specifically, the method for starting the engine in the dual-motor hybrid power system of this embodiment can at least include the following steps:

[0142] (1) When receiving an engine start request, obtain the current state of the first motor 2. If the current state of the first motor 2 is faulty, then execute (2); if the current state of the first motor 2 is normal, then execute (11).

[0143] (2) Obtain the current state data of the vehicle. The current state data of the vehicle at least includes the current vehicle speed, the engine 1 speed, and the coolant temperature of the engine 1. Then execute (3).

[0144] (3) Determine whether the current vehicle speed is less than or equal to a preset vehicle speed threshold and whether the other current state data of the vehicle meets the waiting clutch start condition. If so, that is, the current vehicle speed is less than or equal to the preset vehicle speed threshold and the other current state data of the vehicle meets the waiting clutch start condition, then execute (4).

[0145] (4) Monitor the vehicle speed in real time. Then execute (5).

[0146] (5) Determine the start mode of the driver's intention according to the current state data of the vehicle. Then execute (6).

[0147] The steps for determining the start mode of the driver's intention are as described above.

[0148] (6) Determine whether the pre-drag torque application condition is met according to the engine 1 speed and the start mode of the driver's intention. If so, then execute (7); if not, then execute (8).

[0149] The steps for determining whether the pre-drag torque application condition is met are as described above.

[0150] (7) When the vehicle speed is greater than the preset vehicle speed threshold, generate a first drag start signal and send it to the clutch 3 to control the clutch 3 to drag the engine 1 to start, and control the clutch 3 to output a corresponding pre-drag torque within a set duration since receiving the first drag start signal. Then execute (9).

[0151] (8) When the vehicle speed is greater than the preset vehicle speed threshold, generate a second drag start signal and send it to the clutch 3 to control the clutch 3 to drag the engine 1 to start. After that, then execute (9).

[0152] In this step, in the case where the pre-drag torque application condition is not met, the clutch is started by the existing method without pre-drag torque.

[0153] (9) Determine the fuel injection time of the engine 1 corresponding to the clutch 3 according to the coolant temperature of the engine 1 and the starting mode of the driver's intention. Then execute (10).

[0154] (10) Control the engine 1 to inject fuel at the determined fuel injection time during the process of the clutch 3 dragging the engine 1 to start, so as to complete the start of the engine 1.

[0155] (11) Obtain the current state data of the vehicle. The current state data of the vehicle at least includes the engine speed of the vehicle's engine 1 and the coolant temperature of the engine 1. Then execute (12).

[0156] (12) Judge the starting mode of the driver's intention according to the current state data of the vehicle. Then execute (13).

[0157] (13) Judge whether the pre-dragging torque application condition is satisfied according to the engine speed of the engine 1 and the starting mode of the driver's intention. If so, execute (14); if not, execute (15).

[0158] The step of judging whether the pre-dragging torque application condition is satisfied is as described above.

[0159] (14) Generate a third dragging start signal and send it to the first motor 2 to control the first motor 2 to drag the engine 1 to start, and control the first motor 2 to output the corresponding pre-dragging torque within a set time period since receiving the third dragging start signal. Then execute (16).

[0160] (15) Generate a fourth dragging start signal and send it to the first motor 2 to control the first motor 2 to drag the engine 1 to start. After that, then execute (16).

[0161] (16) Determine the fuel injection time of the engine 1 corresponding to the first motor 2 according to the coolant temperature of the engine 1 and the starting mode of the driver's intention. Then execute (17).

[0162] (17) Control the engine 1 to inject fuel at the determined fuel injection time during the process of the first motor 2 dragging the engine 1 to start, so as to complete the start of the engine 1.

[0163] This embodiment defines a waiting clutch start strategy after the P1 motor fails, and combines the pre-dragging torque strategy and the fuel injection strategy in the P1 motor start or the clutch start, which can effectively improve the smoothness and safety of the engine 1 start.

[0164] Based on the same technical concept, the embodiment of the present invention also provides a starting device 100 for an engine in a dual-motor hybrid power system. As Figure 9As shown, the starting device 100 includes a memory 110 and a processor 120. A control program is stored in the memory 110. When the control program is executed by the processor 120, it is used to implement the starting method of the engine in the dual-motor hybrid power system of any previous embodiment or combination of embodiments.

[0165] The starting device of this embodiment can determine the starting mode intended by the driver according to the current state data of the vehicle, and further determine the fuel injection time of the engine corresponding to the target component (the first motor, i.e., the P1 motor, or the clutch) according to the coolant temperature of the engine and the starting mode intended by the driver. Thus, it can specifically control the time when the engine starts fuel injection during the starting process of the P1 motor or the clutch, preventing phenomena such as starting shock, starting failure, or engine speed drop caused by the engine injecting fuel too early or too late, and improving the smoothness and safety of engine starting.

[0166] Based on the same inventive concept, an embodiment of the present invention further provides a hybrid vehicle, including a dual-motor hybrid power system and the starting device 100 of the engine in the dual-motor hybrid power system described in the previous embodiment. The dual-motor hybrid power system can be referred to Figure 1 as shown.

[0167] According to any one of the above optional embodiments or a combination of multiple optional embodiments, the embodiments of the present invention can achieve the following beneficial effects:

[0168] In the starting method and device of the engine in the dual-motor hybrid power system proposed in the embodiments of the present invention, the starting mode intended by the driver can be determined according to the current state data of the vehicle, and further the fuel injection time of the engine corresponding to the target component (the first motor 2, i.e., the P1 motor, or the clutch 3) can be determined according to the coolant temperature of the engine and the starting mode intended by the driver. Thus, it can specifically control the time when the engine starts fuel injection during the starting process of the P1 motor or the clutch, preventing phenomena such as starting shock, starting failure, or engine speed drop caused by the engine injecting fuel too early or too late, and improving the smoothness and safety of engine starting.

[0169] Further, for the quick start mode, the fuel injection time of the engine is the time when the engine speed is greater than 0. That is to say, the engine does not delay fuel injection, thus ensuring the response speed of the quick start. For the smooth start mode and when the coolant temperature of the engine is greater than the preset warm engine start temperature (i.e., warm engine start), the fuel injection time of the engine is the time when the driving torque of the first motor or the clutch is completely unloaded. That is to say, the engine delays fuel injection until the driving torque is completely unloaded, which can avoid the disturbance impact caused by the incomplete unloading of the torque of the first motor or the clutch and improve the starting smoothness. For the smooth start mode and when the coolant temperature of the engine is less than or equal to the preset warm engine start temperature (i.e., cold engine start), the fuel injection time of the engine is the time when the driving torque of the first motor or the clutch is less than the target torque limit value. Since the engine does not need to wait for the driving torque to be completely unloaded before fuel injection at this time, but can start fuel injection when the driving torque of the first motor or the clutch is less than the corresponding target torque limit value, it prevents the engine speed from dropping or starting failure.

[0170] Further, during the process of the clutch driving the engine to start (i.e., clutch start), by performing active damping control on the second motor 7 (i.e., the drive motor), it is possible to prevent the jitter of the second motor 7 during the clutch start process and further improve the starting smoothness.

[0171] In the specification provided here, a large number of specific details are described. However, it can be understood that the embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures, and technologies are not shown in detail so as not to obscure the understanding of this specification.

[0172] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that within the spirit and principles of the present invention, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the corresponding technical solutions to deviate from the protection scope of the present invention.

Claims

1. A starting method for an engine in a dual-motor hybrid power system, the dual-motor hybrid power system comprising an engine, a first motor connected to the engine, and a clutch connected between the first motor and a transmission system; characterized in that, The starting method includes: When receiving an engine starting request, obtaining the current state data of the vehicle, where the current state data of the vehicle includes the coolant temperature of the engine; Judging the starting mode of the driver's intention according to the current state data of the vehicle; Determining the fuel injection time of the engine corresponding to the target component to be used to drag the engine to start according to the coolant temperature of the engine and the starting mode of the driver's intention, where the target component is the first motor or the clutch; Controlling the engine to inject fuel at the determined fuel injection time during the process of the target component dragging the engine to start; Wherein, the starting mode of the driver's intention includes a quick start mode and a smooth start mode; The step of controlling the engine to inject fuel at the determined fuel injection time during the process of the target component dragging the engine to start includes: When the starting mode of the driver's intention is the quick start mode, obtaining the current speed of the engine in real time during the process of the target component dragging the engine to start; When the current speed of the engine is greater than 0, controlling the engine to inject fuel; When the starting mode of the driver's intention is the smooth start mode, obtaining the dragging torque of the target component in real time during the process of the target component dragging the engine to start; In the case where the coolant temperature of the engine is greater than the preset warm engine starting temperature, when the dragging torque of the target component is completely unloaded, controlling the engine to inject fuel; In the case where the coolant temperature of the engine is less than or equal to the preset warm engine starting temperature, when the dragging torque of the target component is less than the target torque limit value, controlling the engine to inject fuel.

2. The starting method according to claim 1, characterized in that The current state data further includes the throttle state or the driver's requested torque.

3. The starting method according to claim 2, characterized in that The throttle state includes the throttle opening and the throttle change rate; The step of judging the starting mode of the driver's intention according to the current state data of the vehicle includes: Judging whether the throttle opening is greater than the first throttle opening threshold and the throttle change rate is greater than the preset change rate threshold; If so, determining that the starting mode of the driver's intention is the quick start mode; If not, determining that the starting mode of the driver's intention is the smooth start mode; or Judging whether the driver's requested torque is greater than the first wheel end torque threshold; If so, determining that the starting mode of the driver's intention is the quick start mode; If not, determining that the starting mode of the driver's intention is the smooth start mode.

4. The starting method according to claim 2, characterized in that The step of determining the fuel injection time of the engine corresponding to the target component to be used to drag the engine to start according to the coolant temperature of the engine and the starting mode of the driver's intention includes: When the starting mode of the driver's intention is the quick start mode, determining the fuel injection time of the engine as the time when the speed of the engine is greater than 0; When the intended starting mode of the driver is the smooth starting mode and the coolant temperature of the engine is greater than the preset warm engine starting temperature, determine that the fuel injection time of the engine is the time when the drag torque of the target component is completely unloaded; When the intended starting mode of the driver is the smooth starting mode and the coolant temperature of the engine is less than or equal to the preset warm engine starting temperature, look up the correspondence table between the coolant temperature of the engine and the torque limit value of the target component, obtain the target torque limit value of the target component corresponding to the coolant temperature of the engine, and determine that the fuel injection time of the engine is the time when the drag torque of the target component is less than the target torque limit value.

5. The starting method according to claim 4, characterized in that The correspondence table includes a first correspondence table between the coolant temperature of the engine and the torque limit value of the first motor and a second correspondence table between the coolant temperature of the engine and the torque limit value of the clutch; wherein, In the first correspondence table, the coolant temperature of the engine is inversely proportional to the torque limit value of the first motor; In the second correspondence table, the coolant temperature of the engine is inversely proportional to the torque limit value of the clutch.

6. The starting method according to any one of claims 1-5, characterized in that, The dual-motor hybrid power system further includes a second motor connected to the transmission system and used to drive the wheels; The starting method further includes: When the target component is the clutch, during the process of the clutch dragging the engine to start, perform active damping control on the second motor.

7. The starting method according to claim 6, characterized in that, The step of performing active damping control on the second motor includes: Obtain the requested speed of the driver and the actual speed of the second motor; Calculate the difference between the requested speed and the actual speed; Perform proportional-integral control on the second motor according to the difference to compensate the output torque of the second motor.

8. A starting device for an engine in a dual-motor hybrid power system, characterized in that, It includes a memory and a processor, and a control program is stored in the memory. When the control program is executed by the processor, it is used to implement the starting method according to any one of claims 1-7.

9. A hybrid vehicle, characterized in that, It includes a dual-motor hybrid power system and a starting device for the engine in the dual-motor hybrid power system according to claim 8.

Images