Hybrid electric vehicle, and control method and apparatus for dual-electric-motor hybrid system of hybrid electric vehicle

Abstract

A hybrid electric vehicle and a control method and apparatus for a dual-electric-motor hybrid system of the hybrid electric vehicle. The dual-electric-motor hybrid system comprises an engine, a first electric motor, a second electric motor, a transmission and a mode switching clutch, wherein the first electric motor is connected to the engine; an input shaft of the transmission is connected to the engine, the first electric motor and the second electric motor; and the mode switching clutch is separately connected to the second electric motor and the first electric motor. The method comprises: when a hybrid electric vehicle is in a power upshifting mode, in response to a speed regulation gear-shifting request in the mode, acquiring a second electric motor request torque for requesting output of a second electric motor, and determining a speed regulation intervention torque of an input shaft; and if the speed regulation intervention torque is less than or equal to a speed regulation intervention torque capability of the second electric motor, controlling the second electric motor to output the sum of the speed regulation intervention torque and the second electric motor request torque.

Description

Hybrid electric vehicle and control method and device of dual-motor hybrid system Technical Field

[0001] The present application relates to the field of vehicle control technology, and in particular to a control method and device for a hybrid electric vehicle and a dual-motor hybrid system thereof. Background Art

[0002] Currently, some hybrid vehicles are equipped with dual-motor hybrid systems. Controlling the shifting process of the dual-motor hybrid system will affect the power and drivability of the entire vehicle.

[0003] Summary of the Invention

[0004] The present application provides a control method and device for a hybrid vehicle and a dual-motor hybrid system thereof.

[0005] The present application provides a control method for a dual-motor hybrid system of a hybrid vehicle, wherein the dual-motor hybrid system includes an engine, a first motor, a second motor, a transmission, and a mode switching clutch, wherein the first motor is drivingly connected to the engine, the input shaft of the transmission is connected to the engine, the first motor, and the second motor, and the mode switching clutch is connected to the second motor and the first motor, respectively; the method includes:

[0006] When the hybrid vehicle is in a power upshift mode, in response to a speed shift request in the mode, obtaining a second motor request torque requested to be output by the second motor, and determining a speed intervention torque of the input shaft;

[0007] If the speed intervention torque is less than or equal to the speed intervention torque capacity of the second motor, the second motor is controlled to output the sum of the speed intervention torque and the second motor request torque.

[0008] Optionally, the method further includes:

[0009] If the speed intervention torque is greater than the speed intervention torque capacity of the second motor and less than or equal to the speed intervention torque capacity of the input shaft, the second motor is controlled to output the sum of the speed intervention torque capacity of the second motor and the second motor requested torque, and the first motor and / or the engine is controlled to output the remaining intervention torque, and the remaining intervention torque is the difference between the speed intervention torque and the speed intervention torque capacity of the second motor.

[0010] Optionally, the hybrid vehicle includes a battery, the first motor is electrically connected to the battery, and controlling the first motor and / or the engine to output the remaining intervention torque includes:

[0011] obtaining the negative power capacity of the battery;

[0012] If the negative power capacity is not greater than the negative power capacity threshold, at least the first motor is controlled to output a first motor intervention torque; the first motor intervention torque is less than or equal to the residual intervention torque, and the first motor intervention torque is a positive torque or a negative torque.

[0013] Optionally, controlling the first motor and / or the engine to output a remaining intervention torque includes:

[0014] If the negative power capacity is not greater than a negative power capacity threshold, and the remaining intervention torque is less than or equal to the speed regulation intervention torque capacity of the first motor, controlling the first motor to output the first motor intervention torque, and the first motor intervention torque is equal to the remaining intervention torque;

[0015] If the negative power capacity is not greater than the negative power capacity threshold, and the remaining intervention torque is greater than the speed regulation intervention torque capacity of the first motor, the first motor is controlled to output the speed regulation intervention torque capacity of the first motor, and the engine is controlled to output the engine intervention torque, and the engine intervention torque is equal to the difference between the remaining intervention torque and the speed regulation intervention torque capacity of the first motor.

[0016] Optionally, the method further includes:

[0017] If the negative power capacity is greater than the negative power capacity threshold, the torque output by the first motor is reduced within the positive torque range.

[0018] Optionally, the method further includes:

[0019] If the negative power capacity is greater than the negative power capacity threshold and the positive torque output by the first motor is less than the remaining intervention torque, the engine is controlled to output an engine intervention torque, where the engine intervention torque is equal to a difference between the remaining intervention torque and the positive torque output by the first motor.

[0020] Optionally, the hybrid vehicle includes a shift clutch that is engaged when the hybrid vehicle is in the power upshift mode; the method further includes:

[0021] If the speed intervention torque is greater than the speed intervention torque capacity of the input shaft, the second motor is controlled to output the sum of the speed intervention torque capacity of the second motor and the second motor requested torque, the engine is controlled to output the speed intervention torque capacity of the engine, and the first motor is controlled according to the negative power capacity of the battery, and the shift clutch output torque is controlled according to the difference between the speed intervention torque and the speed intervention torque capacity of the input shaft.

[0022] Optionally, controlling the output torque of the shift clutch according to the difference between the speed regulation intervention torque and the speed regulation intervention torque capacity of the input shaft includes:

[0023] determining an adjustment torque according to a series / parallel mode, a shift mode, a gear position, a target speed change rate of the input shaft, and an actual speed change rate of the input shaft of the dual-motor hybrid system;

[0024] determining an output torque of the shifting clutch according to a difference between the speed regulation intervention torque and the speed regulation intervention torque capacity of the input shaft, a feedforward torque of the shifting clutch, and the adjustment torque;

[0025] The shifting clutch is controlled to output the output torque.

[0026] The present application provides a computer-readable storage medium comprising one or more processors for executing the control method of a dual-motor hybrid system of a hybrid electric vehicle as described in any one of the above.

[0027] The present application provides a control device for a dual-motor hybrid system of a hybrid electric vehicle, comprising one or more processors for executing any of the control methods for the dual-motor hybrid system of a hybrid electric vehicle described above.

[0028] The present application also provides a hybrid electric vehicle, comprising:

[0029] A dual-motor hybrid system includes an engine, a first motor, a second motor, a transmission, and a mode switching clutch, wherein the first motor is drivingly connected to the engine, an input shaft of the transmission is connected to the engine, the first motor, and the second motor, and the mode switching clutch is connected to the second motor and the first motor respectively; and

[0030] The control device of the dual-motor hybrid system of the hybrid vehicle as described above is electrically connected to the dual-motor hybrid system.

[0031] In some embodiments, a dual-motor hybrid system includes an engine, a first motor, a second motor, a transmission, and a mode shift clutch. The second motor has a faster response speed during vehicle gear shifting. When the hybrid vehicle is in a power upshift mode, the system determines the speed intervention torque required to adjust the speed of the input shaft based on a speed shift request. If the speed intervention torque is less than or equal to the speed intervention torque capacity of the second motor, the output torque of the second motor is controlled based on the requested torque of the second motor and the speed intervention torque. This allows the transmission input shaft speed to be adjusted more quickly by controlling the output intervention torque of the second motor, thereby maintaining vehicle drivability.

[0032] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0034] FIG1 is a schematic structural diagram of a hybrid vehicle in a series mode according to an embodiment of the present application.

[0035] FIG2 is a schematic structural diagram of a hybrid vehicle in a parallel mode according to an embodiment of the present application.

[0036] FIG3 is a schematic diagram showing a hybrid architecture to which a control method for a dual-motor hybrid system of a hybrid vehicle according to an embodiment of the present application is applied.

[0037] FIG4 is a flow chart showing a method for controlling a dual-motor hybrid system of a hybrid vehicle according to an embodiment of the present application.

[0038] FIG5 is a flow chart showing an embodiment of the step of “controlling the first motor or the engine to output the remaining intervention torque, or controlling the first motor and the engine to jointly output the remaining intervention torque” shown in FIG4 .

[0039] FIG6 is a block diagram showing a structure of a control device for a dual-motor hybrid system of a hybrid vehicle according to an embodiment of the present application. DETAILED DESCRIPTION

[0040] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0041] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. Unless otherwise defined, technical or scientific terms used in this application should have the same ordinary meaning as those understood by persons of ordinary skill in the art to which this application belongs. The terms "first," "second," and similar terms used in this specification and claims do not denote any order, quantity, or importance, but are simply used to distinguish different components. Similarly, terms such as "a" or "an" do not denote a limitation of quantity, but rather denote the presence of at least one. "Multiple" or "several" refer to two or more. Unless otherwise indicated, terms such as "front," "rear," "lower," and / or "upper" are for convenience only and are not intended to limit a specific location or spatial orientation. Terms such as "include" or "comprising" mean that the elements or objects listed before "include" or "comprising" include the elements or objects listed after "include" or "comprising" and their equivalents, and do not exclude other elements or objects. Terms such as "connected" or "connected" are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect.

[0042] As used in this application and the appended claims, the singular forms "a," "an," "said," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0043] When a hybrid vehicle is operating in power upshift mode, the electric motor assists during the torque phase to reduce the perceived deceleration associated with the shift. However, during the speed phase, if the electric motor is not torque-controlled, speed regulation can be slow, impacting vehicle performance and potentially causing the clutch to overheat. Therefore, torque control is essential for dual-motor hybrid systems.

[0044] The dual-motor hybrid system of the present embodiment includes an engine, a first motor, a second motor, a transmission, and a mode shift clutch. The first motor is connected to the engine, the transmission input shaft is connected to the engine, the first motor, and the second motor, and the mode shift clutch is connected to the second motor and the first motor, respectively. When the hybrid vehicle is in power upshift mode, in response to a speed shift request in this mode, a second motor request torque is obtained for the second motor output, and a speed intervention torque of the input shaft is determined. If the speed intervention torque is less than or equal to the speed intervention torque capacity of the second motor, the second motor is controlled to output the sum of the speed intervention torque and the second motor request torque. This application allows for faster adjustment of the transmission input shaft speed when the hybrid vehicle is in power upshift mode.

[0045] This application provides a control method and device for a hybrid electric vehicle and its dual-motor hybrid system. The control method and device for a hybrid electric vehicle and its dual-motor hybrid system are described in detail below, in conjunction with the accompanying drawings. The features of the following embodiments and implementations may be combined unless they conflict.

[0046] FIG1 is a schematic diagram of the structure of a hybrid vehicle in series mode according to an embodiment of the present application. FIG2 is a schematic diagram of the structure of a hybrid vehicle in parallel mode according to an embodiment of the present application. As shown in FIG1 and FIG2 , the dual-motor hybrid system of a hybrid vehicle has three modes: pure electric mode, series mode and parallel mode, and the hybrid vehicle can switch between these modes. As shown in FIG1 and FIG2 , the dual-motor hybrid system includes an engine 1 (e.g., an internal combustion engine, represented by ICE in the figure), a first motor 2 (represented by P1 in the figure), a second motor 3 (represented by P2 in the figure, the second motor 3 can also be called a drive motor), a transmission 5 and a mode switching clutch 4 (represented by C0 in the figure). The first motor 2 is connected to the engine 1 in a driving manner and can drive the engine 1 to start. The input shaft of the transmission 5 is connected to the engine 1, the first motor 2 and the second motor 3, and the mode switching clutch 4 is connected to the second motor 3 and the first motor 2 respectively.

[0047] The hybrid vehicle includes a battery 6, and a first motor 2 electrically connected to the battery 6. The first motor 2 can be used to generate electricity to charge the battery 6. As shown in Figure 1, in series mode, the mode switching clutch 4 is disengaged, and the engine 1 supplies power to the battery 6 and the second motor 3 via the first motor 2. The second motor 3 drives the wheels via the transmission 5. As shown in Figure 2, in parallel mode, the mode switching clutch 4 is engaged (also called coupled), and the engine 1 and the second motor 3 jointly drive the wheels via the transmission 5.

[0048] The control method for the dual-motor hybrid system of a hybrid vehicle according to an embodiment of the present application can be applied to the hybrid architecture shown in FIG3 . As shown in FIG3 , the hybrid architecture includes a first power mechanism, a second power mechanism, and a transmission mechanism. The first power mechanism includes an engine ICE and a first motor P1 connected to each other, and the second power mechanism includes a second motor P2. The transmission mechanism includes a fourth clutch C0 that can be used for mode switching, a double-row planetary gear, a first clutch B1 that can be used for gear shifting control, a second clutch B2, and a third clutch C3. The double-row planetary gear includes a first planetary gear consisting of a first sun gear S1, a first planet carrier PC1, and a first ring gear R1, and a second planetary gear consisting of a second sun gear S2, a second planet carrier PC2, and a second ring gear R2.

[0049] As shown in Figure 3, the output shaft of the first motor P1 can be connected to the second sun gear S2 via the fourth clutch C0 to drive the second sun gear S2. The output shaft of the second motor P2 is also connected to the second sun gear S2 to drive the second sun gear S2. The output shaft of the second motor P2 can also be connected to the first sun gear S1 via the third clutch C3 to drive the first sun gear S1. The first sun gear S1 is connected to one end of the second clutch B2, the other end of which is connected to the hydraulic system. The first planet carrier PC1 is connected to the second ring gear R2. The first planet carrier PC1 and the second ring gear R2 are both connected to one end of the first clutch B1, the other end of which is connected to the hydraulic system. The first ring gear R1 is connected to the second planet carrier PC2. The power input to the double-row planetary gears is transmitted to the wheel ends via the output shaft connected to the first ring gear R1 and the second planet carrier PC2.

[0050] The hybrid architecture described above enables shifting between the three forward gears. Of the first clutch B1, the second clutch B2, and the third clutch C3, first gear occurs only when the first clutch B1 is engaged, second gear occurs only when the second clutch B2 is engaged, and third gear occurs only when the third clutch C3 is engaged. Switching between gears can be achieved by disengaging one of the clutches (i.e., the offgoing clutch) and engaging the other (i.e., the oncoming clutch). The offgoing clutch can also be called an active clutch, and the oncoming clutch can also be called a passive clutch. After the states of the offgoing and oncoming clutches change, the change in the power transmission path causes a change in the transmission ratio, thereby achieving gear shifting.

[0051] Although a hybrid architecture applicable to the embodiment of the present application is shown above, the control method of the dual-motor hybrid system of the hybrid vehicle in the embodiment of the present application is not limited to a specific hybrid architecture.

[0052] The shifting process of the embodiment of the present application includes three stages: the oil filling stage, the torque exchange stage, and the gear shift speed regulation stage. When the gear shift type is power upshift (Power-on upshift) and non-power downshift (Power-off downshift), the order of the three stages is: the oil filling stage, the torque exchange stage and the gear shift speed regulation stage. When the gear shift type is power downshift (Power-on downshift) and non-power upshift (Power-off upshift), the order of the three stages is: the oil filling stage, the gear shift speed regulation stage and the torque exchange stage. Among them, power upshift can also be called accelerator upshift, power downshift can also be called accelerator downshift, non-power upshift can also be called accelerator upshift, and non-power downshift can also be called accelerator downshift.

[0053] The hybrid electric vehicle includes a shift clutch. The shift clutch is engaged when the hybrid electric vehicle is in a power upshift mode. In the embodiment shown in FIG3 , the shift clutch may be a second clutch B2 or a third clutch C3.

[0054] Before the on-coming clutch engages, a certain gap exists between the clutch's active portion (e.g., the driving plate) and the driven portion (e.g., the driven plate). During the filling phase, the clutch is controlled to quickly eliminate this gap, enabling the clutch to reach torque transmission in a shorter period of time. The speed of clutch filling and the pressure response after filling significantly impact drivability and dynamic response during the shift process.

[0055] During the torque exchange phase, the off-going clutch is disengaged and the on-coming clutch is engaged simultaneously, and the clutch torque is exchanged from the off-going clutch to the on-coming clutch.

[0056] During the speed regulation phase, the transmission control unit generates inertial torque (also known as speed regulation intervention torque) by sending a torque reduction or increase request. This inertial torque changes the speed of the powertrain (e.g., engine 1) until the target speed is reached.

[0057] During the torque exchange phase, torque control of the off-going and on-coming clutches is performed at set time intervals. This can be achieved based on a progress percentage, which is equal to the ratio of the current exchange time to the torque exchange duration (i.e., the duration of the torque exchange phase). The current exchange time is equal to the current time minus the start time of the torque exchange phase. Typically, during the torque exchange process, the shift torque allocated to the off-going and on-coming clutches varies linearly (i.e., the absolute value of the shift torque gradient remains unchanged), with the shift torque allocated to the off-going clutch decreasing linearly over time, while the shift torque allocated to the on-coming clutch increases linearly over time.

[0058] FIG4 is a flow chart of a method for controlling a dual-motor hybrid system of a hybrid vehicle according to an embodiment of the present invention. As shown in FIG4 , the method 20 for controlling a dual-motor hybrid system of a hybrid vehicle includes steps 21 to 26 .

[0059] In step 21 , when the hybrid vehicle is in the power upshift mode, in response to a speed shift request in this mode, the second motor request torque requested to be output by the second motor 3 is obtained, and the speed intervention torque of the input shaft of the transmission 5 is determined.

[0060] When a hybrid vehicle is in power upshift mode, during the torque exchange phase, it is typically necessary to control the first motor 2 to compensate for torque to reduce the deceleration caused by the upshift. This can result in a slow speed drop during the shift and speed regulation phase. Furthermore, the increased feedforward torque of the shift clutch can lead to clutch overheating. Therefore, torque intervention is required during the shift and speed regulation phase. The input shaft speed regulation intervention torque is determined based on the speed regulation shift request in this mode.

[0061] In step 22 , it is determined whether the speed regulation intervention torque is less than or equal to the speed regulation intervention torque capacity of the second motor 3 .

[0062] If the speed regulation intervention torque is less than or equal to the speed regulation intervention torque capacity of the second motor 3 , step 23 is executed. In step 23 , the second motor 3 is controlled to output the sum of the speed regulation intervention torque and the second motor request torque.

[0063] The speed regulation intervention torque capability of the second motor 3 can be determined by the following method:

[0064] Maximum speed intervention torque = max (second motor request torque, second motor maximum torque capacity) - second motor request torque;

[0065] Minimum speed regulation intervention torque=min(requested torque of the second motor, minimum torque capacity of the second motor)−requested torque of the second motor.

[0066] The speed intervention torque capability of the second electric machine 3 includes a maximum speed intervention torque and a minimum speed intervention torque of the second electric machine 3. The maximum speed intervention torque is determined based on the difference between the unintervention second electric machine requested torque and the second electric machine maximum torque capability, whichever is greater, and the unintervention second electric machine requested torque. The minimum speed intervention torque is determined based on the difference between the unintervention second electric machine requested torque and the second electric machine minimum torque capability, whichever is less, and the unintervention second electric machine requested torque.

[0067] If the speed intervention torque is less than or equal to the speed intervention torque capacity of the second motor 3 (i.e., the maximum speed intervention torque of the second motor 3), it means that the second motor 3 can output the speed intervention torque. In this case, the torque output by the second motor 3 is the sum of the speed intervention torque and the second motor request torque.

[0068] Due to the fast response of the second motor 3, controlling the torque output of the second motor 3 allows for rapid adjustment of the transmission input shaft speed. The torque output by the second motor 3 is determined based on the second motor's requested torque and the speed regulation intervention torque. This allows for rapid adjustment of the transmission input shaft speed by controlling the intervention torque output of the second motor 3, maintaining vehicle drivability.

[0069] If the speed intervention torque is greater than the speed intervention torque capacity of the second motor, then in step 24 , it is determined whether the speed intervention torque is less than or equal to the speed intervention torque capacity of the transmission input shaft.

[0070] The speed intervention torque capacity of the transmission input shaft is determined by the speed intervention torque capacities of the first electric machine, the second electric machine, and the engine.

[0071] The speed regulation intervention torque capability of the first motor 2 can be determined by the following method:

[0072] Maximum speed intervention torque = max (first motor request torque, first motor maximum torque capacity) - first motor request torque;

[0073] Minimum speed regulation intervention torque=min(requested torque of the first motor, minimum torque capacity of the first motor)−requested torque of the first motor.

[0074] The speed intervention torque capability of the first motor 2 includes a maximum speed intervention torque and a minimum speed intervention torque of the first motor 2. The maximum speed intervention torque is determined based on a difference between the unintervention first motor request torque and the first motor maximum torque capability, whichever is greater, and the unintervention first motor request torque. The minimum speed intervention torque is determined based on a difference between the unintervention first motor request torque and the first motor minimum torque capability, whichever is less, and the unintervention first motor request torque.

[0075] The speed intervention torque capability of engine 1 includes a maximum speed intervention torque and a minimum speed intervention torque of engine 1. The maximum speed intervention torque is determined based on the difference between the unintervention engine request torque and the maximum engine torque capability, whichever is greater, and the unintervention engine request torque. The minimum speed intervention torque is determined based on the difference between the unintervention engine request torque and the minimum engine torque capability, whichever is less, and the unintervention engine request torque.

[0076] The speed regulation intervention torque capacity of the transmission input shaft=the speed regulation intervention torque capacity of the first motor 2 + the speed regulation intervention torque capacity of the second motor 3 + the speed regulation intervention torque capacity of the engine 1 .

[0077] If the speed intervention torque is greater than the speed intervention torque capacity of the second motor 3, it means that the torque output by the second motor 3 is insufficient to cover the speed intervention torque. At this time, it is necessary to determine whether the speed intervention torque is less than or equal to the speed intervention torque capacity of the transmission input shaft.

[0078] If the speed intervention torque is less than or equal to the speed intervention torque capacity of the transmission input shaft, step 25 is executed. In step 25, the second motor 3 is controlled to output the sum of the speed intervention torque capacity of the second motor 3 and the requested torque of the second motor, and the first motor 2 or the engine 1 is controlled to output the remaining intervention torque, or the first motor 2 and the engine 1 are controlled to output the remaining intervention torque together. The remaining intervention torque is the difference between the speed intervention torque and the speed intervention torque capacity of the second motor 3. The remaining intervention torque can be output by the first motor 2 or the engine 1 alone, or by both the first motor 2 and the engine 1.

[0079] FIG5 is a flow chart of an embodiment of the step "controlling the first motor 2 or the engine 1 to output the remaining intervention torque, or controlling the first motor 2 and the engine 1 to jointly output the remaining intervention torque" shown in FIG4. As shown in FIG5, step 25 includes steps 251 to 254.

[0080] In step 251 , the negative power capacity of the battery 6 is obtained.

[0081] The negative power capacity of the battery 6 represents the capacity of the battery 6 that can be charged, and has a positive value. When the first motor 2 is controlled to output torque, the battery 6 is charged. In order to prevent the battery 6 from being overcharged, the negative power capacity of the battery 6 needs to be obtained.

[0082] In step 252 , it is determined whether the negative power capacity is greater than a negative power capacity threshold.

[0083] If the negative power capacity is not greater than the negative power capacity threshold, step 253 is executed. In step 253, at least the first motor 2 is controlled to output a first motor intervention torque. The first motor intervention torque is less than or equal to the residual intervention torque and is positive or negative.

[0084] If the chargeable capacity of the battery 6 is sufficient, the first electric machine 2 outputs a first electric machine intervention torque.

[0085] In some embodiments, step 253 includes: if the remaining intervention torque is less than or equal to the speed regulation intervention torque capability of the first motor 2, controlling the first motor 2 to output the first motor intervention torque, and the first motor intervention torque is equal to the remaining intervention torque; if the remaining intervention torque is greater than the speed regulation intervention torque capability of the first motor 2, controlling the first motor 2 to output the speed regulation intervention torque capability of the first motor 2, and controlling the engine 1 to output the engine intervention torque, and the engine intervention torque is equal to the difference between the remaining intervention torque and the speed regulation intervention torque capability of the first motor 2.

[0086] If the speed regulation intervention torque capability of the first motor 2 is insufficient to cover the remaining intervention torque, it is necessary to control the engine 1 to output the engine intervention torque, and the engine 1 and the first motor 2 jointly output the remaining intervention torque.

[0087] If the negative power capacity is greater than the negative power capacity threshold, step 254 is executed. In step 254 , the torque output by the first motor 2 is reduced within the positive torque range.

[0088] If the chargeable capacity of the battery 6 is insufficient, in order to prevent the battery 6 from being overcharged, the torque output by the first motor 2 is reduced within the positive torque range. The torque output by the first motor 2 may be reduced from the positive torque to zero.

[0089] In some embodiments, step 254 includes: if the positive torque output by the first motor 2 is less than the residual intervention torque, controlling the engine 1 to output the engine intervention torque, where the engine intervention torque is equal to the difference between the residual intervention torque and the positive torque output by the first motor 2. If the positive torque output by the first motor 2 is insufficient to cover the residual intervention torque, controlling the engine 1 to output the engine intervention torque, whereby the engine 1 and the first motor 2 jointly output the residual intervention torque.

[0090] Referring to Figure 4, if the speed intervention torque is greater than the speed intervention torque capacity of the transmission input shaft, step 26 is executed. In step 26, the second motor 3 is controlled to output the sum of the speed intervention torque capacity of the second motor 3 and the requested torque of the second motor, the engine 1 is controlled to output the speed intervention torque capacity of the engine, and according to the negative power capacity of the battery 6, the first motor 2 is controlled, and the shift clutch output torque is controlled according to the difference between the speed intervention torque and the speed intervention torque capacity of the transmission input shaft.

[0091] If the speed intervention torque exceeds the speed intervention torque capacity of the transmission input shaft, it indicates that the speed intervention torque capacity of the transmission input shaft is insufficient to cover the speed intervention torque. To prevent overcharging of battery 6, the torque output by first motor 2 is determined based on the negative power capacity of battery 6. The shift clutch output torque is controlled based on the difference between the speed intervention torque and the speed intervention torque capacity of the transmission input shaft.

[0092] In some embodiments, in step 26, controlling the output torque of the shift clutch according to the difference between the speed regulation intervention torque and the speed regulation intervention torque capacity of the transmission input shaft includes the following steps:

[0093] Determining the adjustment torque based on the series / parallel mode, shift mode, gear position, target speed change rate of the input shaft, and actual speed change rate of the input shaft of the dual-motor hybrid system;

[0094] determining an output torque of the shift clutch based on a difference between the speed regulation intervention torque and the speed regulation intervention torque capacity of the input shaft, a feedforward torque of the shift clutch, and a regulating torque;

[0095] The shifting clutch is controlled to output the output torque.

[0096] The output torque of the shift clutch includes its adjustment torque, feedforward torque, and intervention torque. The adjustment torque is determined by multiplying the difference between the target speed change rate of the input shaft and the actual speed change rate of the input shaft by an adjustment coefficient. The feedforward torque is the sum of the engine torque, the motor torque, and the lockup torque. In some embodiments, the output torque of the shift clutch is controlled by the I term (integral term). The I term (integral term) adjustment coefficient is determined based on the series / parallel mode of the dual-motor hybrid system, the shift mode, the gear position, the target speed change rate of the input shaft, and the actual speed change rate of the input shaft.

[0097] Figure 6 shows a block diagram of a control device for a dual-motor hybrid system of a hybrid vehicle according to an embodiment of the present invention. The control device for a dual-motor hybrid system of a hybrid vehicle is electrically connected to the dual-motor hybrid system of the present invention for controlling the dual-motor hybrid system.

[0098] As shown in FIG6 , the control device of the dual-motor hybrid system of the hybrid electric vehicle includes one or more processors 31 for implementing the control method 20 of the dual-motor hybrid system of the hybrid electric vehicle as described above.

[0099] In some embodiments, the control device for a hybrid vehicle's dual-motor hybrid system may include a computer-readable storage medium 32 , which may store programs callable by a processor 31 and may include non-volatile storage media. In some embodiments, the control device for a hybrid vehicle's dual-motor hybrid system may include a memory 33 and an interface 34 . In some embodiments, the control device for a hybrid vehicle's dual-motor hybrid system may also include other hardware depending on the actual application.

[0100] The computer-readable storage medium 32 of the embodiment of the present application stores a program thereon, which, when executed by the processor 31 , is used to implement the control method 20 of the dual-motor hybrid system of the hybrid electric vehicle as described above.

[0101] The present application may take the form of a computer program product implemented on one or more computer-readable storage media 32 (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing program code. Computer-readable storage media 32 include permanent and non-permanent, removable and non-removable media, and may implement information storage by any method or technology. The information may be computer-readable instructions, data structures, modules of a program, or other data. Examples of computer-readable storage media 32 include but are not limited to: phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device.

[0102] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0103] It should be understood that the present application is not limited to the exact structures described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A control method for a dual-motor hybrid system of a hybrid vehicle, the dual-motor hybrid system comprising an engine, a first motor, a second motor, a transmission and a mode switching clutch, the first motor is drivingly connected to the engine, the input shaft of the transmission is connected to the engine, the first motor and the second motor, the mode switching clutch is connected to the second motor and the first motor respectively, the method comprising: When the hybrid vehicle is in a power upshift mode, in response to a speed shift request in this mode, obtaining a second motor request torque requested to be output by the second motor, and determining a speed intervention torque of the input shaft; If the speed intervention torque is less than or equal to the speed intervention torque capacity of the second motor, the second motor is controlled to output a sum of the speed intervention torque and the second motor request torque.

2. The control method of the dual-motor hybrid system of a hybrid vehicle according to claim 1, the method further comprising: If the speed intervention torque is greater than the speed intervention torque capacity of the second motor and less than or equal to the speed intervention torque capacity of the input shaft, the second motor is controlled to output the sum of the speed intervention torque capacity of the second motor and the requested torque of the second motor, and the first motor and / or the engine are controlled to output the remaining intervention torque, and the remaining intervention torque is the difference between the speed intervention torque and the speed intervention torque capacity of the second motor.

3. The control method of the dual-motor hybrid system of a hybrid vehicle according to claim 2, wherein: The hybrid vehicle includes a battery, the first motor is electrically connected to the battery, and the controlling the first motor and / or the engine to output the remaining intervention torque includes: Obtaining the negative power capacity of the battery; If the negative power capacity is not greater than the negative power capacity threshold, at least the first motor is controlled to output a first motor intervention torque; the first motor intervention torque is less than or equal to the residual intervention torque, and the first motor intervention torque is a positive torque or a negative torque.

4. The control method of the dual-motor hybrid system of a hybrid vehicle according to claim 3, wherein: The controlling the first motor and / or the engine to output the remaining intervention torque comprises: If the negative power capacity is not greater than the negative power capacity threshold, and the remaining intervention torque is less than or equal to the speed regulation intervention torque capacity of the first motor, the first motor is controlled to output the first motor intervention torque, and the first motor intervention torque is equal to the remaining intervention torque; If the negative power capacity is not greater than the negative power capacity threshold, and the remaining intervention torque is greater than the speed intervention torque capacity of the first motor, the first motor is controlled to output the speed intervention torque capacity of the first motor, and the engine is controlled to output the engine intervention torque, and the engine intervention torque is equal to the difference between the remaining intervention torque and the speed intervention torque capacity of the first motor.

5. The control method of the dual-motor hybrid system of a hybrid vehicle according to claim 3, the method further comprising: If the negative power capacity is greater than the negative power capacity threshold, the torque output by the first motor is reduced within the positive torque range.

6. The control method of the dual-motor hybrid system of a hybrid vehicle according to claim 5, the method further comprising: If the negative power capacity is greater than the negative power capacity threshold and the positive torque output by the first motor is less than the remaining intervention torque, the engine is controlled to output an engine intervention torque, wherein the engine intervention torque is equal to a difference between the remaining intervention torque and the positive torque output by the first motor.

7. The control method of the dual-motor hybrid system of a hybrid vehicle according to claim 3, wherein: The hybrid vehicle includes a shift clutch that is engaged when the hybrid vehicle is in the power upshift mode; The method further comprises: If the speed intervention torque is greater than the speed intervention torque capacity of the input shaft, the second motor is controlled to output the sum of the speed intervention torque capacity of the second motor and the requested torque of the second motor, the engine is controlled to output the speed intervention torque capacity of the engine, and the first motor is controlled according to the negative power capacity of the battery, and the shift clutch output torque is controlled according to the difference between the speed intervention torque and the speed intervention torque capacity of the input shaft.

8. The control method of the dual-motor hybrid system of a hybrid vehicle according to claim 7, wherein: The step of controlling the output torque of the shift clutch according to the difference between the speed regulation intervention torque and the speed regulation intervention torque capacity of the input shaft comprises: determining an adjustment torque according to a series / parallel mode, a shift mode, a gear position, a target speed change rate of the input shaft, and an actual speed change rate of the input shaft of the dual-motor hybrid system; determining an output torque of the shift clutch according to a difference between the speed regulation intervention torque and the speed regulation intervention torque capacity of the input shaft, a feedforward torque of the shift clutch, and the adjustment torque; The shifting clutch is controlled to output the output torque.

9. A computer-readable storage medium, comprising one or more processors, for executing the control method of the dual-motor hybrid system of a hybrid electric vehicle according to any one of claims 1 to 8.

10. A control device for a dual-motor hybrid system of a hybrid electric vehicle, comprising one or more processors, configured to execute a control method for a dual-motor hybrid system of a hybrid electric vehicle as claimed in any one of claims 1 to 8.

11. A hybrid electric vehicle comprising: The dual-motor hybrid system includes an engine, a first motor, a second motor, a transmission and a mode switching clutch. The first motor is drivingly connected to the engine, the input shaft of the transmission is connected to the engine, the first motor and the second motor, and the mode switching clutch is connected to the second motor and the first motor respectively; and The control device of the dual-motor hybrid system of the hybrid vehicle as claimed in claim 10 is electrically connected to the dual-motor hybrid system.

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