Control method, control device, and vehicle for a dual-motor hybrid vehicle

Abstract

The application discloses a control method and device of a double-motor hybrid vehicle and the vehicle. The method comprises the following steps: calculating a series driving motor torque drop rate; calculating a series driving motor torque drop time; obtaining comparison value information, which at least comprises a first comparison value and a second comparison value, the first comparison value being a preset comparison value of the series driving motor torque drop rate, and the second comparison value being a preset comparison value of the series driving motor torque drop time; and generating a target control strategy set based on the series driving motor torque drop rate, the series driving motor torque drop time and the comparison value information, the target control strategy set being used for controlling the driving motor to drop its torque at different torque drop slopes. The application solves the technical problem that the power battery is prone to overcharging and overdischarging due to slow engine torque response.

Description

Technical Field

[0001] This invention relates to the field of dual-motor hybrid vehicle control technology, and more specifically, to a control method, control device, and vehicle for a dual-motor hybrid vehicle. Background Technology

[0002] In existing dual-motor hybrid vehicles, when driven at high throttle in series operation mode, the power demanded by the driver is shared by the engine's power generation and the battery's power discharge. The engine's operating point is controlled at a relatively high or even maximum power point of the system. At this time, the engine torque is close to the external characteristic, and the speed reaches the system's set maximum engine speed. When the driver suddenly releases the accelerator pedal (hereinafter referred to as Tipout), the drive motor torque response changes from driving to regenerative braking, transitioning from positive torque to negative torque. The engine operating point changes drastically from the maximum operating point to a lower operating point or even the fuel cut-off operating point. The engine torque response generally has a delay of about 0.2 seconds, which leads to overcharging and over-discharging of the battery.

[0003] There is currently no effective solution to the above problems. Summary of the Invention

[0004] This invention provides a control method, control device, and vehicle for a dual-motor hybrid vehicle, to at least solve the technical problem that the power battery is prone to overcharging and over-discharging due to the slow torque response of the engine.

[0005] According to one aspect of the present invention, a control method for a dual-motor hybrid vehicle is provided, comprising: acquiring the vehicle's operating mode; when the vehicle is determined to be in series mode, calculating the torque reduction rate of the series drive motor; calculating the torque reduction time of the series drive motor; acquiring comparison value information, the comparison value information including at least a first comparison value and a second comparison value, wherein the first comparison value is a preset comparison value of the torque reduction rate of the series drive motor, and the second comparison value is a preset comparison value of the torque reduction time of the series drive motor; generating a target control strategy set based on the torque reduction rate of the series drive motor, the torque reduction time of the series drive motor, and the comparison value information, wherein the target control strategy set is used to control the drive motor to control its torque reduction at different torque reduction slopes, wherein the torque reduction slope includes at least a first reduction slope and a second reduction slope, wherein the first reduction slope is greater than the second reduction slope.

[0006] Optionally, calculating the torque reduction rate of the series drive motor includes: calculating the driver's required torque at a first moment and limiting the driver's required torque to an upper and lower limit to obtain a first torque value; calculating the driver's required torque at a second moment and limiting the driver's required torque to an upper slope to obtain a second torque value, wherein the second moment is the moment before the first moment; and calculating the torque reduction rate of the series drive motor based on the first torque value and the second torque value.

[0007] Optionally, a target control strategy set is generated based on the torque decrease rate of the series drive motor, the torque decrease time of the series drive motor, and the comparison value information, including: determining whether the torque decrease rate of the series drive motor is greater than a first comparison value; if not, generating a first target control instruction in the target control strategy set, the first target control instruction being used to control the drive motor to control its torque decrease at a first decrease slope; if yes, generating one of the first target control instruction and a second target control instruction in the target control strategy set based on the torque decrease time of the series drive motor and the second comparison value, the second target control instruction being used to control the drive motor to control its torque decrease at a second decrease slope.

[0008] Optionally, generating one of a first target control command and a second target control command in the target control strategy set based on the torque drop time of the series drive motor and a second comparison value includes: determining whether the torque drop time of the series drive motor is greater than the second comparison value; if yes, generating the first target control command; if no, generating the second target control command.

[0009] Optionally, after determining that the vehicle is in series mode, the method further includes: acquiring torque information, which includes at least the torque required by the driver; acquiring power information of the vehicle, which includes at least the vehicle's regenerative power and the vehicle's power loss; acquiring battery information of the power battery, which includes at least the power battery's discharge capacity limit; acquiring the engine speed; and generating a third target control command based on the torque information, power information, battery information, and engine speed, wherein the third target control command is used to control the engine to cut off fuel for a preset time period.

[0010] Optionally, a third target control command is generated based on torque information, power information, and battery information, including: generating the third target control command when the driver's required torque is less than a preset value, the regenerated power is not less than the lost power, the discharge capacity limit is not less than a preset discharge comparison value, and the speed is not less than a preset speed comparison value.

[0011] According to another aspect of the present invention, a control device for a dual-motor hybrid vehicle is also provided, comprising: a first acquisition unit for acquiring the vehicle's operating mode; a first calculation unit for calculating the torque reduction rate of the series drive motor when the vehicle is determined to be in series mode; a second acquisition unit for acquiring comparison value information, the comparison value information including at least a first comparison value and a second comparison value, wherein the first comparison value is a preset comparison value of the torque reduction rate of the series drive motor, and the second comparison value is a preset comparison value of the torque reduction time of the series drive motor; a second calculation unit for calculating the torque reduction time of the series drive motor; and a generation unit for generating a target control strategy set based on the torque reduction rate of the series drive motor, the torque reduction time of the series drive motor, and the comparison value information, wherein the target control strategy set is used to control the drive motor to control its torque reduction at different torque reduction slopes, the torque reduction slope including at least a first reduction slope and a second reduction slope, wherein the first reduction slope is greater than the second reduction slope.

[0012] According to another aspect of the present invention, a computer-readable storage medium is also provided, wherein a computer program is stored therein, wherein the computer program is configured to execute the above-described method at runtime.

[0013] According to another aspect of the present invention, a processor is also provided, which is used to run a program, wherein the program is configured to execute the above-described method when running.

[0014] According to another aspect of the present invention, a vehicle is also provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the above-described method through the computer program.

[0015] In this embodiment of the invention, a target control strategy set is generated based on the torque reduction rate, torque reduction time, and comparison value information of the series drive motor. The target control strategy set controls the drive motor to reduce its torque at different torque reduction slopes, thereby optimizing the torque reduction node and rate of the drive motor when the driver significantly releases the accelerator. This achieves the technical effect of coordinating the change in drive motor torque with the change in engine operating point, ensuring that the actual power of the power battery is within the charging and discharging capacity range. This solves the technical problem of overcharging and over-discharging of the power battery due to the slow torque response of the engine. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0017] Figure 1 This is a hardware structure block diagram of a computer terminal for a control method of a dual-motor hybrid vehicle according to an optional embodiment of the present invention.

[0018] Figure 2 This is a flowchart of a control method for a dual-motor hybrid vehicle according to an optional embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the configuration of a dual-motor hybrid vehicle according to one optional embodiment of the present invention;

[0020] Figure 4 This is a structural block diagram of the control module of a dual-motor hybrid vehicle according to an optional embodiment of the present invention;

[0021] Figure 5 This is a flowchart of a control method for a dual-motor hybrid vehicle according to an optional embodiment of the present invention;

[0022] Figure 6 This is a flowchart of a control method for a dual-motor hybrid vehicle according to an optional embodiment of the present invention;

[0023] Figure 7 This is a flowchart of a control method for a dual-motor hybrid vehicle according to an optional embodiment of the present invention;

[0024] Figure 8 This is a time diagram showing the driver's needs and the output changes of each assembly in a dual-motor hybrid vehicle transitioning from driving to braking conditions according to one optional embodiment of the present invention.

[0025] The above figures include the following reference numerals:

[0026] 1. Engine Management System; 2. Engine; 3. Generator Control Unit; 4. Generator Inverter; 5. Generator; 6. Drive Motor Control Unit; 7. Drive Motor Inverter; 8. Drive Motor; 9. Power Battery; 10. Battery Management System; 11. Vehicle Control Unit; 12. Wheel; 13. Clutch; 14. Reduction Gear. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0029] According to one embodiment of the present invention, an embodiment of a control method for a dual-motor hybrid vehicle is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0030] This method embodiment can be executed in an electronic device or similar computing device that includes memory and a processor within a vehicle. Taking an electronic device running in a vehicle as an example, such as... Figure 1 As shown, the vehicle's electronic devices may include one or more processors 102 (processors may include, but are not limited to, central processing units (CPUs), graphics processing units (GPUs), digital signal processing (DSP) chips, microprocessors (MCUs), programmable logic devices (FPGAs), neural network processors (NPUs), tensor processors (TPUs), artificial intelligence (AI) type processors, etc.) and a memory 104 for storing data. Optionally, the vehicle's electronic devices may also include a transmission device 106 for communication functions, an input / output device 108, and a display device 110. Those skilled in the art will understand that... Figure 1 The structures shown are for illustrative purposes only and do not limit the structure of the electronic devices in the vehicle described above. For example, the electronic devices in a vehicle may include more or fewer components than those described above, or have a different configuration than those described above.

[0031] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the control method for a dual-motor hybrid vehicle in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby realizing the aforementioned control method for a dual-motor hybrid vehicle. The memory 104 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to a mobile terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0032] The transmission device 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device may be a Radio Frequency (RF) module, used for wireless communication with the Internet.

[0033] Display device 110 may be, for example, a touchscreen liquid crystal display (LCD) and a touch display (also referred to as a "touchscreen" or "touch display"). The LCD allows a user to interact with the user interface of the mobile terminal. In some embodiments, the mobile terminal has a graphical user interface (GUI), which allows the user to interact with the GUI via finger contact and / or gestures on a touch-sensitive surface. Optional human-computer interaction functions include: creating web pages, drawing, word processing, creating electronic documents, playing games, video conferencing, instant messaging, sending and receiving emails, a call interface, playing digital video, playing digital music, and / or web browsing, etc. Executable instructions for performing the above human-computer interaction functions are configured / stored in one or more processor-executable computer program products or readable storage media.

[0034] This embodiment provides a control method for a dual-motor hybrid vehicle using electronic devices operating in the aforementioned vehicle. Figure 2 This is a flowchart of a control method for a dual-motor hybrid vehicle according to one embodiment of the present invention, such as... Figure 2 As shown, the process includes the following steps:

[0035] Step S10: Obtain the vehicle's operating mode;

[0036] Step S20: When it is determined that the vehicle is in series mode, calculate the torque reduction rate of the series drive motor.

[0037] Step S30: Calculate the torque drop time of the series drive motor;

[0038] Step S40: Obtain comparison value information. The comparison value information includes at least a first comparison value and a second comparison value. The first comparison value is a preset comparison value of the torque decrease rate of the series drive motor, and the second comparison value is a preset comparison value of the torque decrease time of the series drive motor.

[0039] Step S50: Generate a target control strategy set based on the torque decrease rate of the series drive motor, the torque decrease time of the series drive motor, and the comparison value information. The target control strategy set is used to control the drive motor to control its torque decrease with different torque decrease slopes. The torque decrease slope includes at least a first decrease slope and a second decrease slope, wherein the first decrease slope is greater than the second decrease slope.

[0040] Through the above steps, a target control strategy set is generated based on the torque reduction rate, torque reduction time, and comparison value information of the series drive motor. The target control strategy set controls the drive motor to reduce its torque at different torque reduction slopes, thereby optimizing the torque reduction node and rate of the drive motor when the driver significantly releases the accelerator. This achieves the technical effect of coordinating the changes in drive motor torque with the changes in engine operating point, ensuring that the actual power of the power battery is within the charging and discharging capacity range. This solves the technical problem of overcharging and over-discharging of the power battery due to the slow torque response of the engine.

[0041] Figure 3 This is a block diagram of the powertrain structure of a dual-motor hybrid vehicle equipped with the control device according to an embodiment of the present invention. Figure 3 As shown, the system includes an engine management system 1 (EMS), an engine 2, a generator control unit 3 (MCU2), a generator inverter 4 (INV2), a generator 5, a drive motor control unit 6 (MCU1), a drive motor inverter 7 (INV1), a drive motor 8, a power battery 9, a battery management system 10 (BMS), a vehicle control unit 11 (HCU), wheels 12, a clutch 13, and a reduction gear 14.

[0042] The powertrain of a dual-motor hybrid vehicle mainly includes: an engine, a generator, a drive motor, a power battery, a clutch, and a reduction gear. The engine and generator are linked via a gear pair. The generator can start the engine. When the clutch is disengaged, the engine does not directly drive the vehicle; instead, it drives the generator to generate electricity to power either the battery or the drive motor, which then propels the vehicle. When the clutch is engaged, the engine torque is transmitted to the wheels through the clutch and the main reduction gear, allowing the engine and drive motor to jointly drive the hybrid vehicle. Furthermore, Figure 3 In the embodiments of the present invention shown, HCU, EMS, MCU1, MCU2 and BMS are equivalent to the "control device" of the present invention, constituting the main electronic control system of the power domain of the dual-motor hybrid vehicle.

[0043] The main operating modes of dual-motor hybrid vehicles include: 1. **Stop and Engine Off:** The vehicle is parked, the engine is off, the clutch is disengaged, and the HCU stops sending fuel injection and torque commands. 2. **Genius Starts the Engine:** The generator starts the engine, bringing it to a certain speed. The HCU sends fuel injection and torque commands, and the EMS controls engine fuel injection and ignition. The clutch is disengaged. 3. **Engine Shutdown:** The HCU stops sending fuel injection and torque commands, and the EMS controls engine fuel cut-off and shutdown. The clutch is disengaged. 4. **Pure Electric Mode:** When the battery has sufficient charge and the vehicle speed and driver torque demand are low, the engine stops, and the vehicle is driven by the drive motor, whose energy comes entirely from the battery. 5. **Series Mode:** In the first mode, when the vehicle speed increases or the driver's torque demand is high, the engine generates electricity through the generator, which, together with the battery, serves as the energy source for the drive motor, or provides electricity to the drive motor while simultaneously charging the power battery. In the second mode, when the vehicle speed continues to increase and the driver's torque demand decreases, the clutch is engaged, the engine directly drives the vehicle, and the generator generates electricity based on the battery charge and engine load. When the driver's torque demand exceeds the engine's economic limit or the engine response is slow, the drive motor provides assistance. In the third mode, when the vehicle is in motion, the HCU calculates the coasting energy recovery torque based on the vehicle speed and the braking energy recovery torque requested by the ESP (Electronic Stability Program), and controls the engine to either generate electricity or cut off fuel. The drive motor then regenerates and generates electricity according to the energy recovery torque.

[0044] The dual-motor hybrid vehicle has three operating modes: pure electric mode, series mode, and parallel mode. It can automatically switch modes according to the vehicle's driving conditions to achieve better overall vehicle economy. The dual-motor hybrid powertrain mainly consists of an engine, a generator, and a drive motor.

[0045] In a dual-motor hybrid vehicle, the vehicle enters series operation mode after the engine starts. In this mode, the engine drives a generator to produce electricity, which powers both the drive motor and the battery. Alternatively, the engine-generated generator and the battery work together to power the drive motor. To ensure the vehicle's fuel economy in series operation mode, the engine is controlled to operate along the optimal economic curve. This optimal economic curve is derived from the engine's universal characteristics, referencing the isopower line and the specific fuel consumption contour line. When the engine's power demand changes, the corresponding engine torque and speed—that is, the engine operating point—shift up and down along the optimal economic curve.

[0046] In one specific embodiment, the powertrain of a hybrid vehicle with a dual-motor structure has an engine with a peak power of 120kW, a battery peak power of 75kW at room temperature, and a drive motor peak power of 140kW. When driving at high throttle in series operation mode, the driver's power demand is shared by the engine's power generation and the battery's power discharge. The engine operates at a relatively high or even maximum power point, where the engine torque approaches its external characteristic and the engine speed reaches the system's maximum set speed. When the driver suddenly releases the accelerator pedal (tipout), the drive motor torque responds to the driver's intention to switch from drive to regenerative braking, transitioning from positive to negative torque. The engine operating point changes drastically from its maximum operating point to a lower operating point or even the fuel cut-off operating point. The engine torque response typically has a delay of about 0.2 seconds. To ensure the engine operating point drops from its external characteristic torque to the series low-load power generation torque or... When the fuel cut-off torque is applied, the engine speed drops from the system's maximum set engine speed to the series low-load generator speed or the fuel cut-off speed. In the initial stage of adjusting the engine speed, the generator balances the torque with the actual engine torque. Later, it needs to maintain a consistent reverse torque that is a certain value higher than the actual engine torque in order to reduce the engine speed from high to low. At this time, the generator's power output will exceed the charging capacity of the power battery. Therefore, the torque change of the drive motor during driver tipout needs to be coordinated and controlled with the engine generator's operating point adjustment. This is necessary to ensure that when suddenly switching from high-load drive to tipout in series working mode, the actual power of the power battery is within the charging and discharging capacity range, ensuring both drivability and preventing overcharging and over-discharging of the power battery.

[0047] In the initial stage of adjusting the engine speed, the generator needs to balance the torque with the actual engine torque. Later, it needs to maintain a counter-torque that is a certain value higher than the actual engine torque to adjust the engine from high to low speed. Since engine speed, as an inertial quantity, does not change abruptly, the engine speed changes very slowly during the short tipout period. To ensure the engine speed does not rise and begins to decrease, the generator generates electricity at peak power during this time. If the drive motor torque changes too quickly during this period—that is, the drive motor, as an electrical device, suddenly reduces its power consumption—it will cause the generator to charge the battery. If the drive motor only considers the driver's intentions, the actual power output of the battery may exceed its charging capacity. At low temperatures, the battery's charging and discharging capabilities are relatively low. The timing of engine fuel cut-off needs to consider both the change in drive motor torque and the battery's discharge capacity. When the engine cuts off fuel, the drive motor torque is near the positive torque above zero, and the battery will discharge. When the actual power output exceeds the discharge capacity, there is a risk of exceeding the discharge capacity. The battery's actual power output exceeding its charging and discharging capacity will cause a decrease in battery life and capacity.

[0048] The technical solution of this application solves the problem of overcharging and over-discharging of the power battery during tipout, and provides a control method for dual-motor hybrid vehicles. This method comprehensively considers the engine torque response delay, the power battery charging and discharging capacity, and the rate at which the drive motor responds to the driver's driving intentions. By optimizing and calibrating the response time node and rate of the drive motor during high-load tipout in the hybrid vehicle, and simultaneously controlling the engine fuel cut-off time, it achieves coordinated control of the engine generator operating point adjustment and the drive motor torque change, ensuring drivability while preventing the power battery from overcharging and over-discharging.

[0049] Optionally, calculating the torque reduction rate of the series drive motor includes: calculating the driver's required torque at a first moment and limiting the driver's required torque to an upper and lower limit to obtain a first torque value; calculating the driver's required torque at a second moment and limiting the driver's required torque to an upper slope to obtain a second torque value, wherein the second moment is the moment before the first moment; and calculating the torque reduction rate of the series drive motor based on the first torque value and the second torque value.

[0050] The technical solution of this application addresses the risk of battery overcharging when a sudden tipout occurs during high-throttle driving in series operation mode. This is achieved by controlling the timing and rate of torque reduction in the drive motor, taking into account the battery's charging capacity, engine torque response delay, and driving boundaries affecting the driver's intentions. Similarly, controlling the engine fuel cut-off timing, considering both battery discharge capacity and the drive motor torque reduction rate, suppresses the risk of battery over-discharge. This control method is an open-loop control, requiring a closed-loop system with the hybrid vehicle's response and the driver's subjective experience. The effectiveness of the control method is evaluated by assessing the driver's subjective perception of the drive motor torque reduction rate and monitoring the battery's actual power output at different charging and discharging capacities. Furthermore, a dual-motor hybrid vehicle control method is provided. This method comprehensively considers engine torque response delay, battery charging and discharging capacity, and the drive motor's response rate to the driver's intentions. By adjusting the drive motor's response timing and rate during a series high-load tipout and controlling the engine fuel cut-off time, it achieves coordinated control of the engine generator's operating point and drive motor torque changes, satisfying drivability while preventing battery overcharging and over-discharging.

[0051] Optionally, a target control strategy set is generated based on the torque decrease rate of the series drive motor, the torque decrease time of the series drive motor, and the comparison value information, including: determining whether the torque decrease rate of the series drive motor is greater than a first comparison value; if not, generating a first target control instruction in the target control strategy set, the first target control instruction being used to control the drive motor to control its torque decrease at a first decrease slope; if yes, generating one of the first target control instruction and a second target control instruction in the target control strategy set based on the torque decrease time of the series drive motor and the second comparison value, the second target control instruction being used to control the drive motor to control its torque decrease at a second decrease slope.

[0052] Figure 4 This describes the internal structure block diagram of the HCU (Hybrid Control Unit) of a dual-motor hybrid vehicle equipped with the control device of this invention, from calculating the driver's required torque to controlling the torque transmission of the engine, generator, and drive motor assembly. It includes a driver required torque calculation module, a series torque distribution module, an assembly capacity calculation module, and a torque filtering module. Figure 4The flowchart shown illustrates a series of programmed control processes executed within the HCU. The driver's required torque calculation module calculates the driver's wheel-end required torque based on the accelerator pedal opening and vehicle speed, simultaneously outputting the driver's wheel-end required torque (before limitation) and the driver's wheel-end required torque (after limitation) after being limited by the assembly capability calculation module. The assembly capability calculation module receives the available charging / discharging power of the power battery (in kW) reported by the BMS, the maximum and minimum torque of the drive motor (in Nm) reported by MCU1, the maximum and minimum torque of the generator (in Nm) reported by MCU2, and the maximum torque of the engine (in Nm) reported by the EMS. It calculates the maximum and minimum limits of the driver's wheel-end required torque for use by the driver's required torque calculation module, and calculates the upper limit of the engine series torque, the maximum and minimum capacity limits of the generator, and the maximum and minimum capacity limits of the drive motor (wheel-end) for use by the series torque distribution module. The series-parallel torque distribution module, based on the dual-motor hybrid vehicle operating mode, distributes the driver's wheel-end required torque (after limitation), resulting in the engine axle-end torque request (after limitation), the generator axle-end torque request (after limitation), and the drive motor wheel-end torque request (after limitation). The torque filtering module filters the torque request output by the series torque distribution module to obtain the engine shaft end torque request (filtered), generator shaft end torque request (filtered), and drive motor wheel end torque request (filtered).

[0053] Optionally, generating one of a first target control command and a second target control command in the target control strategy set based on the torque drop time of the series drive motor and a second comparison value includes: determining whether the torque drop time of the series drive motor is greater than the second comparison value; if yes, generating the first target control command; if no, generating the second target control command.

[0054] Figure 5 This is a flowchart illustrating the calculation of wheel-end torque of a series drive motor in a dual-motor hybrid vehicle equipped with the control device according to an embodiment of the present invention. Figure 5 The flowchart shown is executed as a series of programmed control processes in the HCU.

[0055] Reference Figure 5First, upper and lower limits are set for the driver's required torque (step S01). After setting the upper and lower limits for the driver's required torque, the result is Min(maximum positive torque capacity of the power system (wheel end), Max(driver's required torque, maximum negative torque capacity of the power system (wheel end))). The upper limit is the maximum positive torque capacity of the power system in series operation mode, and the maximum torque capacity of the power system = Min((power battery's own discharge capacity + generator's maximum power output - accessory power) converted to wheel end torque, drive motor's own positive torque capacity (wheel end)). The lower limit is the maximum negative torque capacity of the drive motor, and the maximum negative torque capacity of the power system = Min((power battery's own charging capacity + generator power consumption when engine fuel is cut off + accessory power) converted to wheel end torque, drive motor's own negative torque capacity) * (-1). The actual power output of the generator is positive when the generator torque is negative and negative when the generator torque is positive. The drive motor's own capacity is reported by MCU1. Next, the slope of the series drive motor's wheel end torque is limited (step S02). The driver's Tipout action is determined by calculating the torque reduction rate of the series drive motor. Then, the battery charging capacity is considered to calculate the torque reduction rate of the series drive motor after Tipout. Finally, the upper and lower limits of the torque slope of the series drive motor at the wheel end are limited (step S03). The upper and lower limits of the torque at the wheel end of the series drive motor after limiting are Min(maximum capacity limit of the drive motor (wheel end)) and Max(minimum capacity limit of the drive motor (wheel end) after limiting the torque slope of the series drive motor at the wheel end)). The upper limit is the maximum positive torque capability of the drive motor, which is calculated as: Maximum positive torque capability of the drive motor = Min((Power battery discharge capability + Generator actual power generation - Accessory power) converted to wheel-end torque, Drive motor positive torque capability (wheel-end)), where the generator actual power generation is positive when the generator torque is negative and negative when the generator torque is positive. The lower limit is the maximum negative torque capability of the drive motor, which is calculated as: Maximum negative torque capability of the drive motor = Min((Power battery charging capability - Generator actual power generation + Accessory power) converted to wheel-end torque, Drive motor negative torque capability) * (-1), where the generator actual power generation is positive when the generator torque is negative and negative when the generator torque is positive. The drive motor capability itself is reported by MCU1.

[0056] Figure 6 This is a flowchart for calculating the torque reduction slope of a series drive motor in a dual-motor hybrid vehicle equipped with the control device of an embodiment of the present invention. Figure 6 The flowchart shown is executed as a series of programmed control processes in the HCU.

[0057] Reference Figure 6First, the torque reduction rate of the series drive motor is calculated (step S01). The torque reduction rate of the series drive motor = (driver's required torque upper and lower limits after limiting) - (driver's required torque slope after limiting) at the previous moment. The driver's required torque upper and lower limits are then calculated. Figure 3 The calculation results of step S01, after limiting the slope of the driver's required torque. Figure 5 The calculation result of step S02.

[0058] Next, it is determined that the torque decrease rate of the series drive motor is greater than the comparison value (step S02). When the torque decrease rate of the series drive motor is not greater than the comparison value (step S02, no), the driver is considered not to be a Tipout driver, and the torque decrease slope 1 of the series drive motor is calculated (step S05). The torque decrease slope 1 of the series drive motor = the decrease slope calculated by one-dimensional lookup table of the torque decrease rate of the series drive motor * correction coefficient 1. The decrease slope calculated by one-dimensional lookup table of the torque decrease rate of the series drive motor is set to a large value (e.g., -10000). The correction coefficient 1 is calculated by one-dimensional lookup table of the power battery charging capacity and is a value between 0 and 1. The smaller the power battery charging capacity is compared with the peak power, the smaller the correction coefficient 1 is set. The decrease rate comparison value is generally set to -40Nm, and the decrease rate corresponds to 4000Nm / s.

[0059] When the torque decrease rate of the series drive motor is greater than the comparison value (if step S02 is true), the timing calculation of the large-rate decrease of the torque of the series drive motor is performed (step S03). The timing starts from the moment when the torque decrease rate of the series drive motor is greater than the decrease rate comparison value (if step S02 is true), and the timing upper limit is set. (If step S02 is not true) the timing ends.

[0060] Then, it is determined that the high-rate decrease time of the series drive motor torque is greater than the comparison value (step S04). When the high-rate decrease time of the series drive motor torque is greater than the comparison value (step S04 is true), it is considered that the operation of coordinating with the engine torque response delay is over, and the decrease slope 1 of the series drive motor torque is calculated (step S05). The decrease time comparison value is calculated by one-dimensional lookup table using the power battery charging capacity. Generally, 20kW corresponds to 0.12s. It is considered that 0.12s is a boundary value that has no impact on drivability. The closer the power battery charging capacity is to the peak power, the smaller the decrease time comparison value is set. The less the power battery charging capacity is to the peak power, the larger the comparison value is set, but not exceeding 0.2s.

[0061] Finally, when the time for the high-rate torque drop of the series drive motor is not greater than the comparison value (step S04, no), it is assumed that the engine torque response delay is being coordinated, and the torque drop slope 2 of the series drive motor is calculated (step S06). The torque drop slope 2 of the series drive motor = the set value of the torque drop rate of the series drive motor * correction coefficient 1. The set value of the torque drop rate of the series drive motor is generally set to a small value (e.g., -1000). The correction coefficient 1 is calculated using a one-dimensional lookup table based on the charging capacity of the power battery, and is a value between 0 and 1. The smaller the power battery charging capacity is compared to the peak power, the smaller the set value of correction coefficient 1.

[0062] Optionally, after determining that the vehicle is in series mode, the method further includes: acquiring torque information, which includes at least the torque required by the driver; acquiring power information of the vehicle, which includes at least the vehicle's regenerative power and the vehicle's power loss; acquiring battery information of the power battery, which includes at least the power battery's discharge capacity limit; acquiring the engine speed; and generating a third target control command based on the torque information, power information, battery information, and engine speed, wherein the third target control command is used to control the engine to cut off fuel for a preset time period.

[0063] Figure 7 This is a flowchart illustrating the calculation of the fuel cut-off flag position for a dual-motor hybrid vehicle equipped with the control device according to an embodiment of the present invention. Figure 7 The flowchart shown is executed as a series of programmed control processes in the HCU.

[0064] Reference Figure 7 First, determine whether the hybrid vehicle is in a non-driving condition (step S01). If the driver's required torque is less than a certain value (defined as -5Nm), it is considered to be in a non-driving condition. If the driver's required torque is greater than a certain value (defined as 2Nm), it is considered to be in a driving condition. If the hybrid vehicle is not in a non-driving condition (step S01, no), set the fuel cut-off flag to 0 (step S06).

[0065] Next, when the hybrid vehicle is in a non-driving condition (step S01 is yes), it is determined whether the regenerative power is greater than the power loss (step S02). Power loss = engine power loss + accessory power + SOC balance power, where engine power loss = engine torque loss * actual engine speed / 9550 * generator efficiency, and SOC balance power = Max(forced generation power, SOC balance charging power) - Max(forced discharge power, SOC balance discharge power). That is, if the regenerative power after engine fuel cut-off can meet the power loss, fuel cut-off can be performed. The higher the battery charge, the easier it is to cut off fuel; the lower the battery charge, the less likely it is to cut off fuel. The regenerative power is the driver's required power in the non-driving condition. Driver required power = driver required torque * drive motor speed / main reduction ratio / 9550. Finally, considering the drive motor efficiency, the above mechanical power is converted into electrical power. The driver's required torque is calculated by looking up a table based on the accelerator pedal opening and vehicle speed. The drive motor speed is reported by the drive motor controller MCU1. When the regenerative power is less than the power loss (step S02 is no), the fuel cut-off flag is set to 0 (step S06).

[0066] Then, when the recovered power is greater than or equal to the lost power (if step S02 is yes), it is determined whether the power battery discharge capacity is greater than or equal to the comparison value (step S03). The power battery discharge capacity is reported by the BMS control. The battery capacity comparison value is generally set to 40kW. If it is higher than 40kW, it is considered that the power battery is in the normal power output range. When the power battery discharge capacity is greater than or equal to the comparison value (if step S02 is no), the fuel cut-off flag is set to 0 (step S06).

[0067] Then, when the power battery discharge capacity is greater than or equal to the comparison value (step S03 is yes), it is determined whether the engine speed is greater than or equal to the comparison value (step S04). The engine speed is reported by the EMS control. The engine speed comparison value is generally set to 1200 rpm. If it is higher than 1200 rpm, it is considered that the NVH after fuel cut-off and the power performance after fuel supply is restored can meet the requirements. When the engine speed is less than the comparison value (step S04 is no), the fuel cut-off flag is set to 0 (step S06).

[0068] Finally, when the engine speed is greater than or equal to the comparison value (when step S04 is true), the fuel cut-off flag is set to 1 after a delay confirmation (step S05). Timing begins when the engine speed is greater than or equal to the comparison value (when step S04 is true), with a maximum timing limit of 10 seconds (calibrable). The delay time comparison value is calculated using a one-dimensional lookup table based on the power battery discharge capacity. When the power battery discharge capacity is higher than 40kW, the delay time comparison value is set to 1 second; when the power battery discharge capacity is lower than 40kW, the lower the discharge capacity, the larger the delay time comparison value, with a maximum setting of 3 seconds. After the fuel cut-off flag is set to 1 after a delay confirmation, the engine power demand = engine loss torque * fuel cut-off target speed (set to 1300rpm) / 9550 * generator efficiency.

[0069] Optionally, a third target control command is generated based on torque information, power information, and battery information, including: generating the third target control command when the driver's required torque is less than a preset value, the regenerated power is not less than the lost power, the discharge capacity limit is not less than a preset discharge comparison value, and the speed is not less than a preset speed comparison value.

[0070] Figure 8 It is a time diagram showing the driver's needs and the output changes of each assembly in a dual-motor hybrid vehicle equipped with the control device of the present invention as it transitions from driving mode to braking mode.

[0071] Reference Figure 8 This section explains the HCU's control over driver needs and the outputs of various assemblies during the transition from driving to braking in a dual-motor hybrid vehicle. Figure 8 In the initial state shown, at point A, the hybrid vehicle is in a series high-load drive condition. The SOC and discharge capacity of the power battery are both within the normal operating range. The generator and the power battery simultaneously provide energy to the drive motor, and the engine operating point corresponds to a higher speed and greater torque. At point B, the driver releases the accelerator pedal but does not depress the brake pedal, the driver's required torque decreases, and the engine's required power decreases accordingly. At point C, the tipout action is completed, and the driver's required torque is the coasting recovery torque. When calculating the torque request of the series drive motor using the control method of this invention, the engine torque response delay is considered to be based on the driver's required torque, decreasing after a certain delay, and then sent to the drive motor after drivability filtering. At point D, the fuel cut-off flag delay confirmation requirement is met, the engine requested power is negative, and the engine torque request is the fuel cut-off torque. Without the control method of this invention, the engine fuel cut-off would be requested at point C. Finally, by observing the actual battery power, the fluctuation range of the actual battery power after using the control method of this invention is significantly reduced and controlled within the charging and discharging capacity range of the power battery. This invention is applicable to the control device of a dual-motor hybrid vehicle equipped with an engine, generator, and drive motor.

[0072] Embodiments of the present invention also provide a control device for a dual-motor hybrid vehicle, comprising: a first acquisition unit for acquiring the vehicle's operating mode; a first calculation unit for calculating the torque reduction rate of the series drive motor when the vehicle is determined to be in series mode; a second acquisition unit for acquiring comparison value information, the comparison value information including at least a first comparison value and a second comparison value, wherein the first comparison value is a preset comparison value of the torque reduction rate of the series drive motor, and the second comparison value is a preset comparison value of the torque reduction time of the series drive motor; a second calculation unit for calculating the torque reduction time of the series drive motor; and a generation unit for generating a target control strategy set based on the torque reduction rate of the series drive motor, the torque reduction time of the series drive motor, and the comparison value information, wherein the target control strategy set is used to control the drive motor to control its torque reduction at different torque reduction slopes, the torque reduction slope including at least a first reduction slope and a second reduction slope, wherein the first reduction slope is greater than the second reduction slope.

[0073] It should be noted that the above modules can be implemented by software or hardware. For the latter, they can be implemented in the following ways, but are not limited to: all the above modules are located in the same processor; or, the above modules are located in different processors in any combination.

[0074] Embodiments of the present invention also provide a storage medium storing a computer program, wherein the computer program is configured to execute the steps in any of the above method embodiments when running.

[0075] Embodiments of the present invention also provide a processor configured to run a computer program to perform the steps in any of the above method embodiments.

[0076] Embodiments of the present invention also provide a vehicle including a memory and a processor, the memory storing a computer program and the processor being configured to run the computer program to perform the steps in any of the above method embodiments.

[0077] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated here.

[0078] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0079] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0080] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0081] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0082] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0083] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0084] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A control method for a dual-motor hybrid vehicle, characterized in that, include: Obtain the vehicle's operating mode; When the vehicle is determined to be in series mode, the torque reduction rate of the series drive motor is calculated; Calculate the torque drop time of the series drive motor; Obtain comparison value information, which includes at least a first comparison value and a second comparison value. The first comparison value is a preset comparison value of the torque decrease rate of the series drive motor, and the second comparison value is a preset comparison value of the torque decrease time of the series drive motor. A target control strategy set is generated based on the torque decrease rate of the series drive motor, the torque decrease time of the series drive motor, and the comparison value information. The target control strategy set is used to control the drive motor to control its torque decrease with different torque decrease slopes. The torque decrease slope includes at least a first decrease slope and a second decrease slope, wherein the first decrease slope is greater than the second decrease slope. A target control strategy set is generated based on the torque decrease rate of the series drive motor, the torque decrease time of the series drive motor, and the comparison value information, including: Determine whether the torque decrease rate of the series drive motor is greater than the first comparison value; If not, generate a first target control instruction in the target control strategy set, the first target control instruction being used to control the drive motor to control its torque to decrease at the first descent slope; If so, one of the first target control instruction and the second target control instruction in the target control strategy set is generated based on the torque drop time of the series drive motor and the second comparison value. The second target control instruction is used to control the drive motor to control its torque drop at the second drop slope. Based on the torque drop time of the series drive motor and the second comparison value, one of the first target control command and the second target control command in the target control strategy set is generated, including: Determine whether the torque drop time of the series drive motor is greater than the second comparison value; If so, generate the first target control command; If not, generate the second target control command.

2. The method according to claim 1, characterized in that, Calculate the torque reduction rate of a series drive motor, including: Calculate the driver's required torque at the first moment and impose upper and lower limits on the driver's required torque to obtain the first torque value; The driver's required torque at the second moment is calculated and the slope of the driver's required torque is limited to obtain a second torque value, wherein the second moment is the moment before the first moment; The torque reduction rate of the series drive motor is calculated based on the first torque value and the second torque value.

3. The method according to claim 1, characterized in that, After determining that the vehicle is in series mode, the method further includes: Obtain torque information, which includes at least the torque required by the driver; Obtain the power information of the vehicle, the power information including at least: the vehicle's regenerative power and the vehicle's power loss; Obtain battery information of the power battery, wherein the battery information includes at least: the discharge capacity limit of the power battery; Get the engine speed; Based on the torque information, power information, battery information, and rotational speed, a third target control command is generated, which is used to control the engine to cut off fuel for a preset time period.

4. The method according to claim 3, characterized in that, A third target control command is generated based on the torque information, the power information, and the battery information, including: The third target control command is generated when the driver's required torque is less than a preset value, the recovered power is not less than the lost power, the discharge capacity limit is not less than a preset discharge comparison value, and the rotational speed is not less than a preset rotational speed comparison value.

5. A control device for a dual-motor hybrid vehicle, characterized in that, include: The first acquisition unit is used to acquire the vehicle's operating mode; The first calculation unit is used to calculate the torque reduction rate of the series drive motor when it is determined that the vehicle is in series mode. The second acquisition unit is used to acquire comparison value information, the comparison value information including at least a first comparison value and a second comparison value, the first comparison value being a preset comparison value of the torque decrease rate of the series drive motor, and the second comparison value being a preset comparison value of the torque decrease time of the series drive motor. The second calculation unit is used to calculate the torque drop time of the series drive motor. The generation unit generates a target control strategy set based on the torque decrease rate of the series drive motor, the torque decrease time of the series drive motor, and the comparison value information. The target control strategy set is used to control the drive motor to control its torque decrease at different torque decrease slopes. The torque decrease slope includes at least a first decrease slope and a second decrease slope, wherein the first decrease slope is greater than the second decrease slope.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the method according to any one of claims 1 to 4.

7. A processor, characterized in that, The processor is used to run a program, wherein the program is configured to execute the method described in any one of claims 1 to 4 when running.

8. A vehicle comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to run the computer program to perform the method described in any one of claims 1 to 4.

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