Control method and device of dual-motor hybrid system of hybrid electric vehicle

Abstract

This application provides a control method and apparatus for a dual-motor hybrid system of a hybrid electric vehicle. The method includes: when the dual-motor hybrid system is in parallel mode, acquiring the input shaft requested torque to be output by the input shaft of the transmission and the first motor requested torque to be output by the first motor; if the input shaft requested torque is greater than the torque capacity of the clutch, and the difference between the input shaft requested torque and the clutch torque capacity is less than the speed regulation intervention torque capacity of the input shaft, controlling the first motor to output the sum of the first motor requested torque and the intervention negative torque, and controlling the engine to output engine torque; the absolute value of the intervention negative torque is less than or equal to the difference between the input shaft requested torque and the clutch torque capacity; the engine torque is a positive torque, equal to the difference between the clutch torque capacity and the intervention negative torque; the clutch torque capacity is the maximum torque that the clutch can transmit. This application can rapidly increase engine speed.

Description

Technical Field

[0001] This application relates to the field of vehicle control technology, and in particular to a control method and apparatus for a dual-motor hybrid system of a hybrid electric vehicle. Background Technology

[0002] Currently, some hybrid vehicles are equipped with dual-motor hybrid systems. The control of the output torque of the dual-motor hybrid system will affect the overall power and drivability of the vehicle.

[0003] In a dual-motor hybrid system, the clutch connects the two motors. Dual-motor hybrid systems include series and parallel modes. When the hybrid vehicle operates in parallel mode, if the input shaft of the transmission requests torque greater than the clutch's torque capacity, torque intervention control of the dual-motor hybrid system is required without exceeding the clutch's torque capacity. Summary of the Invention

[0004] This application provides a control method and device for a dual-motor hybrid system of a hybrid electric vehicle, which can increase the speed more quickly.

[0005] This application provides a control method for a dual-motor hybrid system of a hybrid electric vehicle. The dual-motor hybrid system includes an engine, a first motor, a second motor, a transmission, and a clutch. The first motor is driven and connected to the engine. The input shaft of the transmission is connected to the engine, the first motor, and the second motor. The clutch is connected to the second motor and the first motor respectively.

[0006] The method includes:

[0007] When the dual-motor hybrid system is in parallel mode, the input shaft requested torque and the first motor requested torque are obtained, which request the input shaft of the transmission to output torque and the first motor to output torque.

[0008] If the requested torque of the input shaft is greater than the torque capacity of the clutch, and the difference between the requested torque of the input shaft and the torque capacity of the clutch is less than the speed regulation intervention torque capacity of the input shaft, the first motor is controlled to output the sum of the requested torque of the first motor and the intervention negative torque, and the engine is controlled to output engine torque; the absolute value of the intervention negative torque is less than or equal to the difference between the requested torque of the input shaft and the torque capacity of the clutch; the engine torque is a positive torque, equal to the difference between the torque capacity of the clutch and the intervention negative torque; the torque capacity of the clutch is the maximum torque that the clutch can transmit.

[0009] Optionally, controlling the first motor to output the sum of the requested torque and the intervention negative torque, and controlling the engine to output engine torque, includes:

[0010] The first motor is controlled to output the sum of the requested torque and the maximum intervention negative torque that the first motor can output; the engine torque is equal to the difference between the torque capacity of the clutch and the maximum negative torque.

[0011] Optionally, after controlling the engine to output engine torque, the method includes:

[0012] If the sum of the engine torque output by the engine and the maximum intervention negative torque is less than the input shaft requested torque, the second motor is controlled to output the second motor torque, and the sum of the second motor torque, the engine torque, and the maximum intervention negative torque output by the first motor is equal to the input shaft requested torque.

[0013] Optionally, the method includes:

[0014] When the dual-motor hybrid system is in power upshift mode, in response to the speed adjustment and shifting request in this mode, the system obtains the second motor request torque requested by the second motor and determines the speed adjustment intervention torque of the input shaft.

[0015] If the speed regulation intervention torque is less than the speed regulation intervention torque capability of the second motor, control the second motor to output the sum of the speed regulation intervention torque and the requested torque of the second motor.

[0016] Optionally, the method includes:

[0017] If the speed regulation intervention torque is greater than the speed regulation intervention torque capability of the second motor and less than the speed regulation intervention torque capability of the input shaft, control the second motor to output the sum of the speed regulation intervention torque capability of the second motor and the requested torque of the second motor, and control the first motor or the engine to output the remaining intervention torque, or control the first motor and the engine to jointly output the remaining intervention torque, wherein the remaining intervention torque is the difference between the speed regulation intervention torque and the speed regulation intervention torque capability of the second motor.

[0018] Optionally, the hybrid vehicle includes a battery, the first motor is electrically connected to the battery, and 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, includes:

[0019] Obtain the negative power capacity of the battery;

[0020] If the negative power capacity is less than the negative power capacity threshold, at least the first motor is controlled to output the first motor intervention torque; if the first motor intervention torque is less than or equal to the remaining intervention torque, the first motor intervention torque is either a positive torque or a negative torque.

[0021] Optionally, 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, includes:

[0022] If the negative power capacity is less than the negative power capacity threshold and the remaining intervention torque is less than the speed regulation intervention torque capability 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.

[0023] If the negative power capacity is less than the negative power capacity threshold and the remaining intervention torque is greater than the speed regulation intervention torque capability of the first motor, the first motor is controlled to output the speed regulation intervention torque capability of the first motor, and the engine is controlled to output the engine intervention torque, wherein 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.

[0024] Optionally, after obtaining the negative power capacity of the battery, the method includes:

[0025] If the negative power capacity is greater than the negative power capacity threshold, the torque output of the first motor is reduced within the positive torque range.

[0026] Optionally, after obtaining the negative power capacity of the battery, the method includes:

[0027] If the negative power capacity is greater than the negative power capacity threshold, and the torque output by the first motor is less than the remaining intervention torque, the engine is controlled to output the engine intervention torque, which is equal to the difference between the remaining intervention torque and the torque output by the first motor.

[0028] Optionally, the clutch includes a shift clutch that engages when the hybrid vehicle is in the power upshift mode; the method includes:

[0029] If the speed regulation intervention torque is greater than the speed regulation intervention torque capability of the input shaft, the second motor is controlled to output the sum of the speed regulation intervention torque capability of the second motor and the requested torque of the second motor, the engine is controlled to output the speed regulation intervention torque capability 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 regulation intervention torque and the speed regulation intervention torque capability of the input shaft.

[0030] Optionally, controlling the output torque of the shift clutch based on the difference between the speed regulation intervention torque and the speed regulation intervention torque capability of the input shaft includes:

[0031] The adjustment torque is determined based on the series-parallel connection mode, shifting mode, gear position of the dual-motor hybrid system, the target speed change rate of the input shaft, and the actual speed change rate of the input shaft.

[0032] The output torque of the shift clutch is determined based on the difference between the speed regulation intervention torque and the speed regulation intervention torque capability of the input shaft, the feedforward torque of the clutch, and the adjustment torque.

[0033] The shift clutch is controlled to output the output torque.

[0034] This application provides a computer-readable storage medium including one or more processors for executing a control method for a dual-motor hybrid system of a hybrid electric vehicle as described in any of the preceding claims.

[0035] This application provides a control device for a dual-motor hybrid system of a hybrid electric vehicle, including one or more processors for executing the control method for the dual-motor hybrid system of the hybrid electric vehicle as described in any of the preceding claims.

[0036] This application also provides a hybrid electric vehicle, including:

[0037] A dual-motor hybrid system includes an engine, a first motor, a second motor, a transmission, and a clutch. The first motor is driven by the engine. The input shaft of the transmission connects the engine, the first motor, and the second motor. The clutch is connected to both the second motor and the first motor.

[0038] The control device for the dual-motor hybrid system of the hybrid electric vehicle described above is electrically connected to the dual-motor hybrid system.

[0039] In some embodiments, the dual-motor hybrid system includes an engine, a first motor, a second motor, a transmission, and a clutch, with the clutch connected to both the first and second motors. When the dual-motor hybrid system is in parallel mode, if the input shaft requests a torque greater than the clutch's torque capacity, the first motor is controlled to output negative torque, and based on the negative torque, the engine is controlled to output positive torque. In this way, the vehicle's speed can be increased relatively quickly by controlling the first motor and engine to output intervention torque without exceeding the clutch's torque capacity, thus maintaining the vehicle's driving performance.

[0040] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0041] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0042] Figure 1 The diagram shown is a structural schematic of an embodiment of the hybrid electric vehicle of this application in series mode.

[0043] Figure 2 The diagram shown is a structural schematic of an embodiment of the hybrid electric vehicle of this application in parallel mode.

[0044] Figure 3 The diagram shows a hybrid architecture in which the control method of the dual-motor hybrid system of the hybrid electric vehicle of this application is applied.

[0045] Figure 4 The diagram shown is a flowchart of an embodiment of the control method for a dual-motor hybrid system of a hybrid electric vehicle according to this application.

[0046] Figure 5 The diagram shown is a flowchart of another embodiment of the control method for the dual-motor hybrid system of the hybrid electric vehicle of this application.

[0047] Figure 6 As shown Figure 5 The flowchart shown is an embodiment of the step "controlling the first motor or engine to output the remaining intervention torque, or controlling the first motor and engine to jointly output the remaining intervention torque".

[0048] Figure 7 The diagram shown is a structural block diagram of the control device for a dual-motor hybrid system of a hybrid electric vehicle provided in an embodiment of this application. Detailed Implementation

[0049] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0050] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the application. Unless otherwise defined, the technical or scientific terms used in this application should be understood in their ordinary sense by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the presence of at least one. "A plurality" or "several" indicates two or more. Unless otherwise indicated, the terms "front," "rear," "lower," and / or "upper," etc., are for ease of description only and are not limited to a location or spatial orientation. The terms "comprising" or "including," etc., mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. The terms "connected," "linked," etc., are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect.

[0051] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0052] The dual-motor hybrid system of this application embodiment includes an engine, a first motor, a second motor, a transmission, and a clutch. The first motor is connected to the engine, and the input shaft of the transmission is connected to the engine, the first motor, and the second motor. The clutch is connected to both the second motor and the first motor. The method includes: when the dual-motor hybrid system is in parallel mode, obtaining the input shaft requested torque and the first motor requested torque; if the input shaft requested torque is greater than the clutch torque capacity, and the difference between the input shaft requested torque and the clutch torque capacity is less than the input shaft speed regulation intervention torque capacity, controlling the first motor to output the sum of the first motor requested torque and the intervention negative torque, controlling the engine to output engine torque, the absolute value of the intervention negative torque being less than or equal to the difference between the input shaft requested torque and the clutch torque capacity, the engine torque being positive torque, equal to the difference between the clutch torque capacity and the negative torque; the clutch torque capacity is the maximum torque that the clutch can transmit. This application can increase the speed relatively quickly.

[0053] This application provides a control method and apparatus for a dual-motor hybrid system of a hybrid electric vehicle. The control method and apparatus for a dual-motor hybrid system of a hybrid electric vehicle of this application will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the features in the following embodiments and implementations can be combined with each other.

[0054] Figure 1 The diagram shown is a structural schematic of an embodiment of the hybrid electric vehicle of this application in series mode. Figure 2 The diagram shown is a structural schematic of one embodiment of the hybrid electric vehicle of this application in parallel mode. Figures 1-2 As shown, the dual-motor hybrid system of a hybrid electric vehicle has three modes: pure electric mode, series mode, and parallel mode, and the hybrid vehicle can switch between these modes. Figure 1 and Figure 2 As shown, the dual-motor hybrid system includes an engine 1 (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 clutch 4 (represented by C0 in the figure). The first motor 2 is connected to the engine 1 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. The clutch 4 is connected to both the second motor 3 and the first motor 2.

[0055] The hybrid vehicle includes a battery 6, and a first motor 2 electrically connected to the battery 6. The first motor 2 can generate electricity to charge the battery 6. Figure 1 As shown, in series mode, clutch 4 is disengaged, and engine 1 supplies power to battery 6 and second motor 3 via first motor 2. Second motor 3 drives wheels via transmission 5. Figure 2 As shown, in parallel mode, clutch 4 is engaged (also known as the coupled state), and engine 1 and second motor 3 drive the wheels together through transmission 5.

[0056] The control method for the dual-motor hybrid system of a hybrid electric vehicle according to the embodiments of this application can be applied to... Figure 3 The hybrid architecture shown. Figure 3 As shown, the hybrid architecture includes a first power unit, a second power unit, and a transmission architecture. The first power unit includes an engine ICE and a first motor P1 connected together, and the second power unit includes a second motor P2. The transmission architecture includes a fourth clutch C0 for mode switching, a double-row planetary gear set, a first clutch B1, a second clutch B2, and a third clutch C3 for shift control. The double-row planetary gear set includes a first planetary gear set consisting of a first sun gear S1, a first planet carrier PC1, and a first ring gear R1, and a second planetary gear set consisting of a second sun gear S2, a second planet carrier PC2, and a second ring gear R2.

[0057] like Figure 3 As shown, 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, and the other end of the second clutch B2 is connected to the hydraulic system. The first planetary carrier PC1 is connected to the second ring gear R2, and both the first planetary carrier PC1 and the second ring gear R2 are connected to one end of the first clutch B1, and the other end of the first clutch B1 is connected to the hydraulic system. The first ring gear R1 is connected to the second planetary carrier PC2. The power input to the double-row planetary gears is transmitted from the output shafts connected to the first ring gear R1 and the second planetary carrier PC2 to the gear ends.

[0058] The aforementioned hybrid architecture enables shifting between three forward gears. Of the first clutch B1, second clutch B2, and third clutch C3, only the first clutch B1 engages for first gear, only the second clutch B2 engages for second gear, and only the third clutch C3 engages for third gear. Gear shifting is achieved by disengaging one clutch (the clutch to be disengaged) and engaging the other clutch (the clutch to be engaged). The clutch to be disengaged can also be called the active clutch, and the clutch to be engaged can also be called the passive clutch. The change in the state of the clutches to be disengaged and engaged alters the power transmission path, resulting in a change in the gear ratio, thus achieving gear shifting.

[0059] Although the above illustrates a hybrid architecture that can be applied to the embodiments of this application, the control method of the dual-motor hybrid system of the hybrid electric vehicle in the embodiments of this application is not limited to a specific hybrid architecture.

[0060] The gear shifting process in this embodiment includes three stages: a fuel filling stage, a torque exchange stage, and a gear shifting and speed adjustment stage. When the gear shift type is a power upshift (Power on up) and a power downshift (Power off down), the order of these three stages is: fuel filling stage, torque exchange stage, and gear shifting and speed adjustment stage. Conversely, when the gear shift type is a power downshift (Power on down) and a power offup, the order of these three stages is: fuel filling stage, gear shifting and speed adjustment stage, and torque exchange stage. Power upshifting can also be referred to as upshifting by pressing the accelerator, and power downshifting can also be referred to as downshifting by pressing the accelerator. Similarly, non-power upshifting can be referred to as upshifting by releasing the accelerator, and non-power downshifting can also be referred to as downshifting by releasing the accelerator.

[0061] Clutch 4 includes a shift clutch. The shift clutch engages when the hybrid vehicle is in power upshift mode. Figure 3 In the embodiment shown, the shift clutch can be a second clutch B2 or a third clutch C3.

[0062] Before the clutch engages, there is a certain gap between the driving part (such as the driving plate) and the driven part (such as the driven plate) of the clutch. During the oil filling stage, the clutch to be engaged is controlled to quickly eliminate this gap, so that the clutch to be engaged can reach the torque transmission state in a short time. The speed of clutch oil filling and the pressure follow-through after oil filling have a significant impact on the drivability and power response during gear shifting.

[0063] During the torque exchange phase, the disengagement of the clutch to be disengaged and the disengagement of the clutch to be engaged occur simultaneously, and the torque of the clutch is transferred from the clutch to be disengaged to the clutch to be engaged.

[0064] During the speed regulation phase, the transmission control unit generates inertial torque, also known as speed regulation intervention torque, by sending requests to reduce or increase torque. Under the action of inertial torque, the speed of the power unit (such as engine 1) is changed until the target speed is reached.

[0065] During the torque exchange phase, torque control of the clutches to be disengaged and engaged is performed at set time intervals, which can be achieved based on a progress percentage. The progress percentage is equal to the ratio of the current exchanged time to the torque exchange duration (i.e., the duration of the torque exchange phase), where the current exchanged time is equal to the current moment minus the start moment of the torque exchange phase. Typically, during torque exchange, the shift torque allocated to the clutches to be disengaged and engaged changes linearly (i.e., the absolute value of the shift torque gradient remains constant). Specifically, the shift torque allocated to the clutches to be disengaged decreases linearly with time, while the shift torque allocated to the clutches to be engaged increases linearly with time.

[0066] Figure 4 The diagram shown is a flowchart of one embodiment of the control method 20 for a dual-motor hybrid system of a hybrid electric vehicle according to this application. Figure 4 As shown, the control method 20 for the dual-motor hybrid system of a hybrid electric vehicle includes steps 21 to 24.

[0067] Step 21: When the dual-motor hybrid system is in parallel mode, obtain the input shaft requested torque of the input shaft of the request transmission 5 and the first motor requested torque of the request first motor 2.

[0068] Step 22: Determine whether the torque requested by the input shaft is greater than the torque capacity of clutch 4.

[0069] If the input shaft requests a torque less than the torque capacity of clutch 4, proceed to step 23 without torque intervention.

[0070] If the requested torque of the input shaft is greater than the torque capacity of clutch 4, proceed to step 24. If the difference between the requested torque of the input shaft and the torque capacity of clutch 4 is less than the speed regulation intervention torque capacity of the input shaft, control the first motor 2 to output the sum of the requested torque of the first motor and the intervention negative torque, and control the engine 1 to output engine torque. The absolute value of the intervention negative torque is less than or equal to the difference between the requested torque of the input shaft and the torque capacity of clutch 4. The engine torque is a positive torque, equal to the difference between the torque capacity of clutch 4 and the intervention negative torque. The torque capacity of clutch 4 is the maximum torque that clutch 4 can transmit. Figure 3 In the embodiment shown, clutch 4 includes a fourth clutch C0, and the torque capacity of clutch 4 is the maximum torque that the fourth clutch C0 can transmit.

[0071] The speed regulation intervention torque capability of the input shaft is determined by the speed regulation intervention torque capability of the first motor 2, the second motor 3, and the engine 1.

[0072] The speed regulation intervention torque capability of the first motor 2 can be determined by the following method:

[0073] Maximum speed regulation intervention torque = max(requested torque of the first motor without intervention, maximum torque capacity of the first motor) - requested torque of the first motor without intervention;

[0074] Minimum speed regulation intervention torque = min(requested torque of the first motor without intervention, minimum torque capacity of the first motor) - requested torque of the first motor without intervention.

[0075] The speed regulation intervention torque capability of the first motor 2 includes the maximum speed regulation intervention torque and the minimum speed regulation intervention torque of the first motor 2. The maximum speed regulation intervention torque is determined by the difference between the larger of the uninterrupted requested torque of the first motor and the maximum torque capability of the first motor, and the uninterrupted requested torque of the first motor. The minimum speed regulation intervention torque is determined by the difference between the smaller of the uninterrupted requested torque of the first motor and the minimum torque capability of the first motor, and the uninterrupted requested torque of the first motor.

[0076] The speed regulation intervention torque capability of the second motor 3 can be determined by the following method:

[0077] Maximum speed regulation intervention torque = max(requested torque of the second motor without intervention, maximum torque capacity of the second motor) - requested torque of the second motor without intervention;

[0078] Minimum speed regulation intervention torque = min(requested torque of the second motor without intervention, minimum torque capacity of the second motor) - requested torque of the second motor without intervention.

[0079] The speed regulation intervention torque capability of the second motor 3 includes the maximum speed regulation intervention torque and the minimum speed regulation intervention torque of the second motor 3. The maximum speed regulation intervention torque is determined by the difference between the larger of the uninterrupted second motor requested torque and the second motor's maximum torque capability, and the uninterrupted second motor requested torque. The minimum speed regulation intervention torque is determined by the difference between the smaller of the uninterrupted second motor requested torque and the second motor's minimum torque capability, and the uninterrupted second motor requested torque.

[0080] The speed regulation intervention torque capability of engine 1 includes the maximum speed regulation intervention torque and the minimum speed regulation intervention torque of engine 1. The maximum speed regulation intervention torque is determined by the difference between the larger of the uninterrupted engine's requested torque and the engine's maximum torque capability, and the uninterrupted engine's requested torque. The minimum speed regulation intervention torque is determined by the difference between the smaller of the uninterrupted engine's requested torque and the engine's minimum torque capability, and the uninterrupted engine's requested torque.

[0081] The speed regulation intervention torque capability of the input shaft = the speed regulation intervention torque capability of the first motor 2 + the speed regulation intervention torque capability of the second motor 3 + the speed regulation intervention torque capability of the engine 1.

[0082] If the requested torque of the input shaft is greater than the torque capacity of clutch 4, it means that the input shaft of clutch 4 cannot output the requested torque. If the difference between the requested torque of the input shaft and the torque capacity of clutch 4 is less than the speed regulation intervention torque capacity of the input shaft, the first motor 2 is controlled to output the sum of the requested torque and the intervention negative torque, and the engine 1 is controlled to output positive engine torque. Priority is given to controlling the first motor 2 to output the intervention negative torque, and the torque output of engine 1 is controlled according to the intervention negative torque. In this way, the positive torque output of engine 1 can be increased as much as possible without exceeding the torque capacity of clutch 4, which is beneficial for increasing the speed. For example, if the requested torque of the input shaft is 400 Nm, the torque capacity of clutch 4 is 300 Nm, and the speed regulation intervention torque capacity of the first motor 2 is ±100 Nm, the first motor 2 is controlled to output a negative torque of -100 Nm, and the engine 1 is controlled to output 400 Nm.

[0083] In some embodiments, step 24, controlling the sum of the output of the first motor 2, the requested torque of the first motor, and the intervention negative torque, to control the output of engine torque of engine 1, includes:

[0084] The first motor 2 is controlled to output the sum of the first motor's requested torque and the first motor's maximum intervention negative torque; the engine torque is equal to the difference between the clutch 4's torque capacity and the maximum intervention negative torque.

[0085] If the sum of the engine torque output by engine 1 and the maximum intervention negative torque is less than the input shaft requested torque, the second motor 3 is controlled to output the second motor torque. The sum of the second motor torque, the engine torque, and the maximum intervention negative torque output by the first motor is equal to the input shaft requested torque.

[0086] Controlling the first motor 2 to output the maximum intervention negative torque allows the engine 1 to output as much positive torque as possible, which is beneficial for increasing the speed. If the intervention torque output by the engine 1 and the first motor 2 is less than the torque requested by the input shaft, the second motor 3 is controlled to jointly output the intervention torque.

[0087] Figure 5 The diagram shown is a flowchart of another embodiment of the control method 20 for a dual-motor hybrid system of a hybrid electric vehicle according to this application. Figure 5 As shown, the control method of the dual-motor hybrid system of a hybrid electric vehicle includes steps 25 to 30.

[0088] Step 25: When the dual-motor hybrid system is in power upshift mode, in response to the speed adjustment and shifting request in this mode, the second motor request torque requested by the second motor 3 is obtained, and the speed adjustment intervention torque of the input shaft is determined.

[0089] When the dual-motor hybrid system is in upshift mode, the first motor (Motor 2) typically needs to compensate for torque during the torque exchange phase to reduce the deceleration caused by upshifting. Therefore, during the shift speed adjustment phase, this may result in a slower speed drop, and the increased feedforward torque of the shift clutch may cause it to overheat. Thus, torque intervention is required during the shift speed adjustment phase. The speed adjustment intervention torque of the input shaft is determined based on the speed adjustment and shift request in this mode.

[0090] Step 26: Determine whether the speed regulation intervention torque is less than the speed regulation intervention torque capability of the second motor 3.

[0091] If the speed regulation intervention torque is less than the speed regulation intervention torque capability of the second motor 3, execute step 27 to control the second motor 3 to output the sum of the speed regulation intervention torque and the requested torque of the second motor.

[0092] If the speed regulation intervention torque is less than the speed regulation intervention torque capability of the second motor 3, it means that the second motor 3 can output the speed regulation intervention torque. The torque output by the second motor 3 is the sum of the speed regulation intervention torque and the torque requested by the second motor.

[0093] Because the second motor 3 has a fast response, controlling its output torque allows for quick adjustment of the vehicle's speed. The output torque of the second motor 3 is determined based on the requested torque and the speed adjustment intervention torque. This allows for rapid adjustment of the vehicle's speed by controlling the output intervention torque of the second motor 3, thus maintaining the vehicle's driving performance.

[0094] Step 28: If the speed regulation intervention torque is greater than the speed regulation intervention torque capability of the second motor, determine whether the speed regulation intervention torque is less than the speed regulation intervention torque capability of the input shaft.

[0095] If the speed regulation intervention torque is greater than the speed regulation intervention torque capability of the second motor 3, it means that the torque output by the second motor 3 is insufficient to cover the speed regulation intervention torque. At this time, it is necessary to determine whether the speed regulation intervention torque is less than the speed regulation intervention torque capability of the input shaft.

[0096] If the speed regulation intervention torque is less than the speed regulation intervention torque capability of the input shaft, step 29 is executed. The second motor 3 is controlled to output the sum of its speed regulation intervention torque capability and the requested torque of the second motor. Simultaneously, the first motor 2 or engine 1 is controlled to output the remaining intervention torque, or both the first motor 2 and engine 1 are controlled to output the remaining intervention torque. The remaining intervention torque is the difference between the speed regulation intervention torque and the speed regulation intervention torque capability of the second motor 3. The remaining intervention torque can be output by the first motor 2 or engine 1 alone, or by both of them together.

[0097] Figure 6 As shown Figure 5 The flowchart shown is a representation of one embodiment of the step "controlling the first motor 2 or engine 1 to output the remaining intervention torque, or controlling the first motor 2 and engine 1 to jointly output the remaining intervention torque". Figure 6 As shown, step 29 includes steps 291 to 294.

[0098] Step 291: Obtain the negative power capacity of battery 6.

[0099] The negative power capacity of battery 6 represents the rechargeable capacity of battery 6. When controlling the output torque of the first motor 2, battery 6 is charged. To prevent battery 6 from being overcharged, it is necessary to obtain the negative power capacity of battery 6.

[0100] Step 292: Determine whether the negative power capacity is greater than the negative power capacity threshold.

[0101] If the negative power capacity is less than the negative power capacity threshold, proceed to step 293, controlling at least the first motor 2 to output the first motor intervention torque. The first motor intervention torque is less than or equal to the remaining intervention torque, and the first motor intervention torque can be either positive or negative.

[0102] If the rechargeable capacity of battery 6 is sufficient, the first motor 2 outputs the first motor intervention torque.

[0103] In some embodiments, step 293 includes: if the remaining intervention torque is less than the speed regulation intervention torque capability of the first motor 2, controlling the first motor 2 to output the first motor intervention torque, the first motor intervention torque being 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, the engine intervention torque being equal to the difference between the remaining intervention torque and the speed regulation intervention torque capability of the first motor.

[0104] If the speed regulation 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.

[0105] If the negative power capacity is greater than the negative power capacity threshold, proceed to step 294, which reduces the torque output of the first motor 2 within the positive torque range.

[0106] If the battery 6 is not charged to a sufficient capacity, in order to prevent the battery 6 from being overcharged, the torque output of the first motor 2 is reduced within the positive torque range. The torque output of the first motor 2 can be reduced from positive torque to zero.

[0107] In some embodiments, step 294 includes: if the positive torque output by the first motor 2 is less than the remaining intervention torque, controlling the engine 1 to output the engine intervention torque, the engine intervention torque being equal to the difference between the remaining intervention torque and the positive torque of the first motor 2. If the positive torque output by 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.

[0108] refer to Figure 5 If the speed regulation intervention torque is greater than the speed regulation intervention torque capability of the input shaft, step 30 is executed, controlling the second motor 3 to output the sum of the speed regulation intervention torque capability of the second motor 3 and the requested torque of the second motor, controlling the engine 1 to output the speed regulation intervention torque capability of the engine, and controlling the first motor 2 according to the negative power capacity of the battery 6, and controlling the output torque of the shift clutch according to the difference between the speed regulation intervention torque and the speed regulation intervention torque capability of the input shaft.

[0109] If the speed regulation intervention torque is greater than the speed regulation intervention torque capability of the input shaft, it indicates that the speed regulation intervention torque capability of the input shaft is insufficient to cover the speed regulation intervention torque. To prevent overcharging of battery 6, the torque output of the first motor 2 is determined based on the negative power capacity of battery 6. The shift clutch output is controlled based on the difference between the speed regulation intervention torque and the speed regulation intervention torque capability of the input shaft.

[0110] In some embodiments, step 30, controlling the output torque of the shift clutch based on the difference between the speed regulation intervention torque and the speed regulation intervention torque capability of the input shaft, includes the following steps:

[0111] The adjustment torque is determined based on the series-parallel connection mode, shifting 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.

[0112] The output torque of the shift clutch is determined based on the difference between the speed regulation intervention torque and the speed regulation intervention torque capability of the input shaft, the feedforward torque of the clutch, and the adjustment torque.

[0113] The shift clutch is controlled to output the aforementioned output torque.

[0114] The output torque of the shift clutch includes its regulating torque, feedforward torque, and intervention torque. The regulating torque is determined by multiplying the difference between the target rate of change of the input shaft's speed and the actual rate of change of the input shaft's speed with an adjustment coefficient. In some embodiments, the output torque of the shift clutch is controlled by phase I. The phase I adjustment coefficient is determined based on the series-parallel mode of the dual-motor hybrid system, the shift mode, the gear, and the target rate of change of the input shaft's speed and the actual rate of change of the input shaft's speed.

[0115] Figure 7 The diagram shows a structural block diagram of the control device for a dual-motor hybrid system of a hybrid electric vehicle provided in an embodiment of this application. The control device for the dual-motor hybrid system of the hybrid electric vehicle is electrically connected to the dual-motor hybrid system of this application and is used to control the dual-motor hybrid system.

[0116] like Figure 7 As shown, the control device for the dual-motor hybrid system of a hybrid electric vehicle includes one or more processors 41 for implementing the control method 20 for the dual-motor hybrid system of the hybrid electric vehicle as described above.

[0117] In some embodiments, the control device for the dual-motor hybrid system of a hybrid electric vehicle may include a computer-readable storage medium 42, which may store a program that can be invoked by a processor 41, and may include a non-volatile storage medium. In some embodiments, the control device for the dual-motor hybrid system of a hybrid electric vehicle may include memory 43 and an interface 44. In some embodiments, the control device for the dual-motor hybrid system of a hybrid electric vehicle may also include other hardware depending on the actual application.

[0118] The computer-readable storage medium 42 of this application embodiment stores a program that, when executed by the processor 41, is used to implement the control method 20 of the dual-motor hybrid system of the hybrid electric vehicle as described above.

[0119] This application may take the form of a computer program product implemented on one or more computer-readable storage media 42 (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing program code. The computer-readable storage media 42 includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented using any method or technology. The information may be computer-readable instructions, data structures, program modules, or other data. Examples of computer-readable storage media 42 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 technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0120] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0121] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A control method for a dual-motor hybrid system of a hybrid electric vehicle, characterized in that, The dual-motor hybrid system includes an engine, a first motor, a second motor, a transmission, and a clutch. The first motor is driven by the engine. The input shaft of the transmission is connected to the engine, the first motor, and the second motor. The clutch is connected to the second motor and the first motor, respectively. The method includes: When the dual-motor hybrid system is in parallel mode, the input shaft requested torque and the first motor requested torque are obtained, which request the input shaft of the transmission to output torque and the first motor to output torque. If the requested torque of the input shaft is greater than the torque capacity of the clutch, and the difference between the requested torque of the input shaft and the torque capacity of the clutch is less than the speed regulation intervention torque capacity of the input shaft, the first motor is controlled to output the sum of the requested torque of the first motor and the intervention negative torque, and the engine is controlled to output engine torque; the absolute value of the intervention negative torque is less than or equal to the difference between the requested torque of the input shaft and the torque capacity of the clutch; the engine torque is a positive torque, equal to the difference between the torque capacity of the clutch and the intervention negative torque; the torque capacity of the clutch is the maximum torque that the clutch can transmit.

2. The control method for a dual-motor hybrid system of a hybrid electric vehicle according to claim 1, characterized in that, The control of the first motor to output the sum of the requested torque and the intervention negative torque, and the control of the engine to output engine torque, include: The first motor is controlled to output the sum of the requested torque of the first motor and the maximum intervention negative torque that the first motor can output; the engine torque is equal to the difference between the torque capacity of the clutch and the maximum intervention negative torque.

3. The control method for a dual-motor hybrid system of a hybrid electric vehicle according to claim 2, characterized in that, After controlling the engine to output engine torque, the method includes: If the sum of the engine torque output by the engine and the maximum intervention negative torque is less than the input shaft requested torque, the second motor is controlled to output the second motor torque, and the sum of the second motor torque, the engine torque, and the maximum intervention negative torque output by the first motor is equal to the input shaft requested torque.

4. The control method for a dual-motor hybrid system of a hybrid electric vehicle according to claim 1, characterized in that, The method includes: When the dual-motor hybrid system is in power upshift mode, in response to the speed adjustment and shifting request in this mode, the system obtains the second motor request torque requested by the second motor and determines the speed adjustment intervention torque of the input shaft. If the speed regulation intervention torque is less than the speed regulation intervention torque capability of the second motor, control the second motor to output the sum of the speed regulation intervention torque and the requested torque of the second motor.

5. The control method for a dual-motor hybrid system of a hybrid electric vehicle according to claim 4, characterized in that, The method includes: If the speed regulation intervention torque is greater than the speed regulation intervention torque capability of the second motor and less than the speed regulation intervention torque capability of the input shaft, control the second motor to output the sum of the speed regulation intervention torque capability of the second motor and the requested torque of the second motor, and control the first motor or the engine to output the remaining intervention torque, or control the first motor and the engine to jointly output the remaining intervention torque, wherein the remaining intervention torque is the difference between the speed regulation intervention torque and the speed regulation intervention torque capability of the second motor.

6. The control method for a dual-motor hybrid system of a hybrid electric vehicle according to claim 5, characterized in that, The hybrid vehicle includes a battery, and a first motor is electrically connected to the battery. Controlling the first motor or the engine to output residual intervention torque, or controlling the first motor and the engine to jointly output the residual intervention torque, includes: Obtain the negative power capacity of the battery; If the negative power capacity is less than the negative power capacity threshold, at least the first motor is controlled to output the first motor intervention torque; if the first motor intervention torque is less than or equal to the remaining intervention torque, the first motor intervention torque is either a positive torque or a negative torque.

7. The control method for a dual-motor hybrid system of a hybrid electric vehicle according to claim 6, characterized in that, The control of the first motor or the engine to output the remaining intervention torque, or the control of the first motor and the engine to jointly output the remaining intervention torque, includes: If the negative power capacity is less than the negative power capacity threshold and the remaining intervention torque is less than the speed regulation intervention torque capability 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 less than the negative power capacity threshold and the remaining intervention torque is greater than the speed regulation intervention torque capability of the first motor, the first motor is controlled to output the speed regulation intervention torque capability of the first motor, and the engine is controlled to output the engine intervention torque, wherein 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.

8. The control method for a dual-motor hybrid system of a hybrid electric vehicle according to claim 6, characterized in that, After obtaining the negative power capacity of the battery, the method includes: If the negative power capacity is greater than the negative power capacity threshold, the torque output of the first motor is reduced within the positive torque range.

9. The control method for a dual-motor hybrid system of a hybrid electric vehicle according to claim 8, characterized in that, After obtaining the negative power capacity of the battery, the method includes: If the negative power capacity is greater than the negative power capacity threshold, and the torque output by the first motor is less than the remaining intervention torque, the engine is controlled to output the engine intervention torque, which is equal to the difference between the remaining intervention torque and the torque output by the first motor.

10. The control method for a dual-motor hybrid system of a hybrid electric vehicle according to claim 6, characterized in that, The clutch includes a shift clutch that engages when the hybrid vehicle is in the power upshift mode; the method includes: If the speed regulation intervention torque is greater than the speed regulation intervention torque capability of the input shaft, the second motor is controlled to output the sum of the speed regulation intervention torque capability of the second motor and the requested torque of the second motor, the engine is controlled to output the speed regulation intervention torque capability 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 regulation intervention torque and the speed regulation intervention torque capability of the input shaft.

11. The control method for a dual-motor hybrid system of a hybrid electric vehicle according to claim 10, characterized in that, The step of controlling the output torque of the shift clutch based on the difference between the speed regulation intervention torque and the speed regulation intervention torque capability of the input shaft includes: The adjustment torque is determined based on the series-parallel connection mode, shifting mode, gear position of the dual-motor hybrid system, the target speed change rate of the input shaft, and the actual speed change rate of the input shaft. The output torque of the shift clutch is determined based on the difference between the speed regulation intervention torque and the speed regulation intervention torque capability of the input shaft, the feedforward torque of the clutch, and the adjustment torque. The shift clutch is controlled to output the output torque.

12. A computer-readable storage medium, characterized in that, It includes one or more processors for executing the control method of a dual-motor hybrid system for a hybrid electric vehicle as described in any one of claims 1-11.

13. A control device for a dual-motor hybrid system of a hybrid electric vehicle, characterized in that, It includes one or more processors for executing the control method of a dual-motor hybrid system for a hybrid electric vehicle as described in any one of claims 1-11.

14. A hybrid electric vehicle, characterized in that, include: A dual-motor hybrid system includes an engine, a first motor, a second motor, a transmission, and a clutch. The first motor is driven by the engine. The input shaft of the transmission is connected to the engine, the first motor, and the second motor. The clutch is connected to both the second motor and the first motor. and The control device for the dual-motor hybrid system of the hybrid electric vehicle as described in claim 13 is electrically connected to the dual-motor hybrid system.

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