Control method, control device and vehicle for series four-wheel drive of hybrid vehicle

Abstract

This invention discloses a control method, control device, and vehicle for a hybrid vehicle with series four-wheel drive. The method includes: acquiring wheel-end information, which includes at least one of the following: required wheel-end torque and required wheel-end driving force; determining motor output information based on the wheel-end information, including the operating parameter output values ​​of the front-drive motor and the rear-drive motor; determining the total motor drive power based on the motor output information; determining the engine output power based on the total motor drive power; determining engine output information based on the engine output power, including the engine's operating parameter output values; generating a target control command based on the motor output information and the engine output information; and controlling the target vehicle's motor and engine to output a target power based on the target control command. This invention solves the technical problem of insufficiently precise power control in the series four-wheel drive mode of hybrid vehicles in the prior art.

Description

Technical Field

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

[0002] Hybrid electric vehicles (HEVs) differ from traditional vehicles in their powertrain systems. The addition of a drive motor and battery in HEVs results in distinct driving methods and energy-saving principles. Due to the unique nature of their powertrains, HEVs allow for the development and design of various control strategies to enhance drivability, power, and fuel economy.

[0003] Currently, hybrid electric vehicle (HEV) powertrain configurations include series, parallel, and series-parallel. Series HEVs offer advantages such as simple structure and easy control, but suffer from low efficiency and high cost. Parallel HEVs offer good fuel economy, but place higher demands on engine, transmission, and other components, and have a more complex control process. Series-parallel HEVs combine the characteristics of both series and parallel systems, thus offering more possible control methods and extensions. Existing series four-wheel drive control methods for hybrid vehicles suffer from inaccurate engine output power due to their coarse control approach, resulting in poor four-wheel drive response performance.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This invention provides a control method, control device, and vehicle for a hybrid vehicle with series four-wheel drive, to at least solve the technical problem of insufficient power control in the series four-wheel drive mode of hybrid vehicles in the prior art.

[0006] According to one aspect of the present invention, a control method for a hybrid vehicle with series four-wheel drive is provided. The method includes: acquiring wheel-end information, the wheel-end information including at least one of the following: required wheel-end torque and required wheel-end driving force; determining motor output information based on the wheel-end information, the motor output information including the operating parameter output values ​​of a front-drive motor and the operating parameter output values ​​of a rear-drive motor; determining the total motor drive power based on the motor output information; determining the engine output power based on the total motor drive power; determining engine output information based on the engine output power, the engine output information including the operating parameter output values ​​of the engine; generating a target control command based on the motor output information and the engine output information; and controlling the target vehicle's motor and engine to output a target power based on the target control command.

[0007] Optionally, determining the engine output power based on the total power of the electric motor drive includes: determining the generator output power based on the total power of the electric motor drive; and determining the engine output power based on the generator output power.

[0008] Optionally, determining the generator output power based on the total motor drive power includes: obtaining the generator's power generation efficiency; and calculating the generator output power as the quotient of the total motor drive power and the power generation efficiency.

[0009] Optionally, determining the engine output power based on the generator output power includes: obtaining the engine efficiency; and calculating the quotient of the generator output power and the engine efficiency as the engine output power.

[0010] Optionally, determining engine output information based on engine output power includes: obtaining the engine universal characteristic curve; looking up the value on the engine universal characteristic curve based on the engine output power to obtain the optimal specific fuel consumption under the engine output power; and determining engine output information based on the optimal specific fuel consumption and engine output power.

[0011] Optionally, obtaining wheel-end information includes: obtaining vehicle status information, which includes at least vehicle speed; and determining wheel-end information based on the vehicle status information.

[0012] Optionally, the method further includes: detecting whether the target vehicle is in a series four-wheel drive mode; if so, obtaining vehicle status information.

[0013] According to another aspect of the present invention, a control device for a hybrid vehicle with series four-wheel drive is also provided, comprising: an acquisition unit for acquiring wheel-end information, the wheel-end information including at least one of the following: required wheel-end torque and required wheel-end driving force; a first determination unit for determining motor output information based on the wheel-end information, the motor output information including the operating parameter output values ​​of a front-drive motor and the operating parameter output values ​​of a rear-drive motor; a second determination unit for determining the total motor drive power based on the motor output information; a third determination unit for determining the engine output power based on the total motor drive power; a fourth determination unit for determining engine output information based on the engine output power, the engine output information including the operating parameter output values ​​of the engine; a fifth determination unit for generating a target control command based on the motor output information and the engine output information; and a control unit for controlling the motor and engine output target power of the target vehicle based on the target control command.

[0014] According to another aspect of the present invention, a computer-readable storage medium is also provided, wherein a computer program is stored therein, and the computer program is configured to execute the above-described method when it is run.

[0015] 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.

[0016] In this embodiment of the invention, the method of determining motor output information based on wheel end information is adopted. The engine output information is determined based on engine output power, and the target control command is generated based on motor output information and engine output information. This achieves the purpose of accurately controlling the target vehicle's motor and engine output target power, thereby solving the technical problem of insufficient power control in the series four-wheel drive mode of hybrid vehicles in the prior art. Attached Figure Description

[0017] 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:

[0018] Figure 1 This is a hardware structure block diagram of a computer terminal for a control method of a hybrid vehicle series four-wheel drive according to an optional embodiment of the present invention.

[0019] Figure 2 This is a flowchart of a control method for a hybrid vehicle series four-wheel drive according to an optional embodiment of the present invention;

[0020] Figure 3 This is a flowchart of a control method for a hybrid vehicle series four-wheel drive according to an optional embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the structure of a hybrid vehicle powertrain system according to one optional embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the structure of a hybrid vehicle power system in pure electric crawling mode according to an optional embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the structure of a hybrid vehicle power system in four-wheel drive start mode according to one optional embodiment of the present invention;

[0024] Figure 7 This is a schematic diagram of the structure of a hybrid vehicle power system in idle power generation mode according to an optional embodiment of the present invention;

[0025] Figure 8 This is a schematic diagram of the structure of a hybrid vehicle powertrain system in pure electric four-wheel drive mode according to an optional embodiment of the present invention;

[0026] Figure 9 This is a schematic diagram of the hybrid vehicle powertrain system in series four-wheel drive mode according to one optional embodiment of the present invention;

[0027] Figure 10 This is a schematic diagram of the hybrid vehicle powertrain system in engine direct drive mode according to one optional embodiment of the present invention;

[0028] Figure 11 This is a schematic diagram of the structure of a hybrid vehicle powertrain system in parallel four-wheel drive mode according to an optional embodiment of the present invention;

[0029] Figure 12 This is a schematic diagram of the hybrid vehicle power system in a driving and charging four-wheel drive mode according to an optional embodiment of the present invention;

[0030] Figure 13 This is a schematic diagram of the structure of a hybrid vehicle power system in energy recovery mode according to an optional embodiment of the present invention;

[0031] Figure 14 This is a schematic diagram of the hybrid vehicle power system in a stop-start mode according to one optional embodiment of the present invention. Detailed Implementation

[0032] 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.

[0033] 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.

[0034] According to an embodiment of the present invention, an embodiment of a control method for a hybrid vehicle with series four-wheel drive is also 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.

[0035] The methods and embodiments provided in this application can be executed on mobile terminals, computer terminals, or similar computing devices. Figure 1 A hardware block diagram of a computer terminal (or mobile device) for implementing a control method for series four-wheel drive in hybrid vehicles is shown. Figure 1 As shown, the computer terminal 10 (or mobile device 10) may include one or more processors (shown as 102a, 102b, ..., 102n in the figure) (the processor may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.), a memory 104 for storing data, and a transmission module 106 for communication functions. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of a BUS bus), a network interface, a power supply, and / or a camera. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the aforementioned electronic device. For example, computer terminal 10 may also include... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0036] It should be noted that the aforementioned one or more processors and / or other data processing circuits are generally referred to herein as "data processing circuits". These data processing circuits may be wholly or partially embodied in software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuits may be a single, independent processing module, or wholly or partially integrated into any other element within the computer terminal 10 (or mobile device). As involved in the embodiments of this application, the data processing circuit serves as a processor control mechanism (e.g., selection of a variable resistor termination path connected to an interface).

[0037] The memory 104 can be used to store software programs and modules for application software, such as the program instructions / data storage device corresponding to the hybrid vehicle series four-wheel drive control method in this embodiment of the invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory 104, thereby realizing the aforementioned hybrid vehicle series four-wheel drive control method. 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, and these remote memories can be connected to the computer terminal 10 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.

[0038] 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 communication provider of the computer terminal 10. 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 106 may be a Radio Frequency (RF) module, used for wireless communication with the Internet.

[0039] The display can be, for example, a touchscreen liquid crystal display (LCD) that allows the user to interact with the user interface of the computer terminal 10 (or mobile device).

[0040] Under the aforementioned operating environment, this application provides the following: Figure 2 The control method for series four-wheel drive in hybrid vehicles is shown. Figure 2 This is a flowchart of a control method for a hybrid vehicle with series four-wheel drive according to an embodiment of the present invention.

[0041] like Figure 2 As shown, the method includes:

[0042] The process involves: acquiring wheel-end information, including at least one of the following: required wheel-end torque and required wheel-end driving force; determining motor output information based on the wheel-end information, including the operating parameter output values ​​of the front-drive motor and the rear-drive motor; determining the total motor drive power based on the motor output information; determining the engine output power based on the total motor drive power; determining engine output information based on the engine output power, including the engine's operating parameter output values; generating a target control command based on the motor output information and the engine output information; and controlling the target vehicle's motor and engine to output the target power based on the target control command.

[0043] In this embodiment of the invention, the method of determining motor output information based on wheel end information is adopted. The engine output information is determined based on engine output power, and the target control command is generated based on motor output information and engine output information. This achieves the purpose of accurately controlling the target vehicle's motor and engine output target power, thereby solving the technical problem of insufficient power control in the series four-wheel drive mode of hybrid vehicles in the prior art.

[0044] Optionally, determining the engine output power based on the total power of the electric motor drive includes: determining the generator output power based on the total power of the electric motor drive; and determining the engine output power based on the generator output power.

[0045] Optionally, determining the generator output power based on the total motor drive power includes: obtaining the generator's power generation efficiency; and calculating the generator output power as the quotient of the total motor drive power and the power generation efficiency.

[0046] Optionally, determining the engine output power based on the generator output power includes: obtaining the engine efficiency; and calculating the quotient of the generator output power and the engine efficiency as the engine output power.

[0047] Optionally, determining engine output information based on engine output power includes: obtaining the engine universal characteristic curve; looking up the value on the engine universal characteristic curve based on the engine output power to obtain the optimal specific fuel consumption under the engine output power; and determining engine output information based on the optimal specific fuel consumption and engine output power.

[0048] Optionally, obtaining wheel-end information includes: obtaining vehicle status information, which includes at least vehicle speed; and determining wheel-end information based on the vehicle status information.

[0049] Optionally, the method further includes: detecting whether the target vehicle is in a series four-wheel drive mode; if so, obtaining vehicle status information.

[0050] Figure 3 This is a flowchart of a control method for a hybrid vehicle series four-wheel drive according to an optional embodiment of the present invention;

[0051] The specific steps are as follows:

[0052] (1) Based on the current vehicle status (such as vehicle speed and overall vehicle parameters), calculate the wheel-end driving force F using the following method. t and torque T AL ;

[0053] The resistance a vehicle experiences during travel includes rolling resistance F. f air resistance F w Slope resistance F i and acceleration resistance F j The driving force of a vehicle is equal to the sum of all the aforementioned resistances. Unlike traditional cars, the driving force F of a new energy hybrid vehicle is... t The total torque T generated by the power source (combining the engine and drive motor) is AL The power is transmitted to the wheels through the transmission mechanism, thus driving the vehicle.

[0054] The dynamic equation of the vehicle is:

[0055] F t =F f +F w +F i +F j

[0056] Further deduction leads to:

[0057]

[0058] Further deduction leads to:

[0059]

[0060] In the above formula, r is the wheel radius, m is the vehicle mass, f is the rolling resistance coefficient, and C D δ is the air resistance coefficient, A is the frontal area, α is the road slope, δ is the vehicle rotational mass conversion factor, and v is the vehicle speed. The coefficients that take into account the speed ratio and efficiency of the transmission mechanism can be calculated and calibrated based on the overall vehicle configuration.

[0061] (2) Based on the obtained power source output torque value T AL Through the torque distribution control strategy within the VCU, the torque output allocated to the front drive motor is T1, and the torque output allocated to the rear drive motor is T2, i.e., T AL =T1+T2

[0062] (3) Based on the vehicle speed, the front drive motor speed n1 and the rear drive motor speed n2 can be calculated using existing automotive theory.

[0063] (4) Furthermore, the power P required for dual-motor drive can be calculated by using the torque and speed of the front drive motor and the rear drive motor. AL :

[0064]

[0065] (5) Further, based on the calculated power P required for dual-motor drive AL This can be converted into the battery's output power. In series four-wheel drive mode, the battery's output power is the power generated by the engine through the generator. Considering the generator's power generation efficiency (denoted as η1), the calculated power at the generator's input terminal is...

[0066] (5) Furthermore, based on the calculated generator input power P3, it can be converted into the engine output power P4. In series four-wheel drive mode, the generator power is derived from the engine output power. Considering the engine efficiency (denoted as η2), the calculated engine output power is:

[0067] (6) Further, based on the calculated engine output power P4, the optimal specific fuel consumption under this power is obtained by looking up the value on the engine universal characteristic curve. Based on the specific fuel consumption value, the engine torque T3 and speed n3 are further calculated by looking up the table.

[0068] (7) These calculations are performed in the VCU program. After obtaining the engine torque T3 and speed n3, the VCU sends the signal value to the EMS.

[0069] (8) The EMS controls the engine to output the specified torque and speed values ​​according to the instructions of the VCU, thereby ultimately realizing the series four-wheel drive control of the hybrid vehicle to meet the driver's vehicle driving needs.

[0070] Figure 4 This is a schematic diagram of the structure of a hybrid vehicle powertrain system according to one optional embodiment of the present invention;

[0071] Powertrain configuration schemes such as Figure 4 As shown, it mainly consists of components such as engine, generator, front drive motor, rear drive motor, coupling mechanism, clutch, reducer, and drive axle, as well as controllers corresponding to each powertrain component.

[0072] The powertrain component controllers include the vehicle controller (VCU), generator controller (MCU1), front drive motor controller (MCU2), and rear drive motor controller (MCU3), battery management system (BMS), and engine controller (EMS).

[0073] The various controllers communicate via a CAN network. The VCU is the core controller of the vehicle, used to coordinate and control other subsystems. The EMS controls the engine, MCU1 controls the generator, MCU2 controls the front drive motor, MCU3 controls the rear drive motor, and the BMS controls the power battery.

[0074] like Figure 4 As shown, the engine, generator, and front-drive motor are located on the same drive shaft. A clutch is installed between the front-drive motor and the engine, with the engine output connected to the clutch and the other end of the clutch connected to the front-drive motor. The front-drive motor transmits power to the front wheels through a reducer, coupling mechanism, and differential. The engine can drive independently or together with the front-drive motor. They are located on the front drive axle and are coupled by a dedicated coupling mechanism to achieve front-wheel drive. The rear-drive motor transmits power to the rear wheels through a transmission mechanism, which, after passing through the rear drive axle's transmission mechanism, achieves rear-wheel drive. The engine and generator are connected, and the engine generates electricity through the generator, which can be used to charge the power battery. The power battery discharges to supply electrical energy to the front and rear-drive motors. During vehicle operation, the vehicle control unit (VCU) receives real-time operating status data from each powertrain component. Based on signals from the driver's accelerator and brake pedals, as well as feedback from various component states, the VCU uses control algorithms to determine the power and torque output of the powertrain, ultimately achieving real-time control of various operating modes of the hybrid system.

[0075] A hybrid power system configuration mainly consists of an engine, generator and its controller, a front motor and its controller, a rear motor and its controller, a coupling mechanism, a clutch, a power battery, a drive axle, and a reducer. By designing a reasonable control method, fuel consumption and emissions can be reduced more effectively, and the four-wheel drive response performance of hybrid vehicles can be improved. This application proposes a hybrid power system configuration and control method. The power source includes an engine, generator, front drive motor, rear drive motor, coupling mechanism, clutch, and drive axle. Through the design of control strategies, the hybrid vehicle effectively achieves pure electric driving, series drive, and parallel drive functions. Simultaneously, it can fully utilize the vehicle's four-wheel drive performance, reduce fuel consumption and emissions, thereby further improving the power and economic performance of the hybrid vehicle.

[0076] Figure 5 This is a schematic diagram of the hybrid vehicle power system in pure electric crawling mode according to one optional embodiment of the present invention. When the vehicle speed is 0, the gear lever is in D or R gear, the engine is off, the brake master cylinder pressure signal is greater than the threshold value, the parking brake is not activated, and the power battery SOC is greater than the threshold value (e.g., >30%), the driver releases the brake pedal (without pressing the accelerator), and then controls the power system to drive the vehicle in pure electric crawling mode. In this mode, the control states of each assembly are as follows: engine off, generator off, front drive motor off, rear drive motor driven, clutch disengaged, and power battery discharged.

[0077] Figure 6 This is a schematic diagram of the hybrid vehicle power system in four-wheel drive start-up mode according to one optional embodiment of the present invention. When the vehicle speed is 0, the gear lever is in D or R gear, the engine is in driving mode, the brake master cylinder pressure is greater than the threshold value, the parking brake is not activated, and the power battery SOC is greater than the threshold value (e.g., >40%), if the vehicle is detected to be on a low-traction road surface such as ice, snow, or muddy slopes, the driver releases the brake pedal and presses the accelerator, thus controlling the power system to drive the vehicle in four-wheel drive start-up mode. In this mode, the control state of each assembly is as follows: engine off, generator off, front motor driven, rear motor driven, power battery discharging, and clutch disengaged. If the power battery SOC is less than the threshold value (e.g., <35%), then in this mode, the control state of each assembly is as follows: engine started, generator off, front motor off, rear motor driven, clutch engaged, and power battery discharging.

[0078] Figure 7This is a schematic diagram of the hybrid vehicle power system in idle power generation mode according to one optional embodiment of the present invention. When the vehicle speed is 0, the gear lever is in P or N gear, the engine is running, the battery SOC is less than a threshold (e.g., <25%), and the air conditioning needs heating or defrosting / defogging, the power system is controlled to enter idle power generation mode. The engine is controlled to maintain the target power generation speed, the generator is in power generation mode, and the power generation capacity meets the charging needs of the power battery and the power needs of accessory electrical appliances. In this mode, the control state of each assembly is as follows: engine driven, generator generating electricity, front motor stopped, rear motor stopped, clutch disengaged, and power battery charging.

[0079] Figure 8 This is a schematic diagram of the hybrid vehicle powertrain system in pure electric four-wheel drive mode according to one optional embodiment of the present invention. When the vehicle speed is greater than 0 and less than a threshold value, the gear lever is in D or R gear, the SOC of the power battery is greater than a threshold value (e.g., >50%), the brake pedal is not depressed, the accelerator pedal is depressed, the air conditioner has no need for heating or defrosting / defogging, and the vehicle drive power is less than a threshold value, the vehicle drive requirements can be met by using either the front drive motor or the rear drive motor. At this time, the powertrain system is controlled to drive the vehicle in pure electric four-wheel drive mode. In this mode, the control state of each assembly is as follows: engine off, generator off, front drive motor or rear drive motor driving, power battery discharging, and clutch disengaged. If the vehicle drive power is greater than a threshold value, the vehicle is driven by both the front drive motor and the rear drive motor. At this time, the control state of each assembly is as follows: engine off, generator off, front drive motor driving and rear drive motor driving, clutch disengaged, and power battery discharging.

[0080] Figure 9 This is a schematic diagram of the hybrid vehicle powertrain system in series four-wheel drive mode according to one optional embodiment of the present invention. When the vehicle speed is greater than a threshold (e.g., >50km / h), the gear lever is in D or R gear, the SOC of the power battery is less than a threshold (e.g., <40%), the brake pedal is not depressed, the accelerator pedal is depressed, and the driver's required torque is less than a certain value, the powertrain system is controlled to drive the vehicle in series four-wheel drive mode. The engine generates electricity through the generator to charge the power battery. The effective energy utilization rate of the entire powertrain system is achieved by controlling and adjusting the engine load. The power battery discharges to the front drive motor and the rear drive motor. In this mode, the control state of each assembly is as follows: engine drive, generator power generation, front drive motor drive, rear drive motor drive, clutch disengagement, and power battery charging and discharging.

[0081] Figure 10This is a schematic diagram of the hybrid vehicle powertrain system in engine direct drive mode according to one optional embodiment of the present invention. When the vehicle speed is greater than a threshold (e.g., >70km / h), the gear lever is in D or R gear, the power battery SOC is within the normal range, the power battery has sufficient charge and does not need to be charged, the brake pedal is not depressed, the accelerator pedal is depressed, the driver's required torque is within a certain range, and at this time the engine's independent driving efficiency is high, operating in the high-efficiency region, the powertrain system is controlled to drive the vehicle in engine direct drive mode. In this mode, the control of each assembly is as follows: engine drive, generator off, front drive motor off, rear drive motor off, clutch engaged, and power battery not charging or discharging.

[0082] Figure 11 This is a schematic diagram of the hybrid vehicle powertrain system in parallel four-wheel drive mode according to one optional embodiment of the present invention. When the vehicle speed is greater than a threshold (e.g., >80km / h), the gear lever is in D or R gear, the SOC of the power battery is greater than the threshold, the brake pedal is not depressed, the accelerator pedal is depressed, and the driver's torque demand is greater than the threshold (greater than in engine direct drive mode, i.e., there is a greater driving demand), during acceleration, if the engine torque cannot meet the driver's torque demand due to response lag or limitations imposed by its external characteristics, the electric motor can assist in supplementing the drive torque to improve power response performance. At this time, the powertrain system is controlled to drive the vehicle in parallel four-wheel drive mode. In this mode, the control state of each assembly is as follows: engine driven, generator off, front drive motor driven, rear drive motor driven, clutch engaged, and power battery discharged.

[0083] Figure 12 This is a schematic diagram of the hybrid vehicle power system in a driving-charging four-wheel drive mode according to one optional embodiment of the present invention. When the vehicle speed is greater than a threshold (e.g., >60 km / h), the gear lever is in D or R gear, the SOC of the power battery is less than a threshold (e.g., <40%), the brake pedal is not depressed, the accelerator pedal is depressed, and the driver's required torque is less than a certain value, the power system is controlled to drive the vehicle in a driving-charging mode. The engine drives the vehicle while simultaneously generating electricity through the generator to charge the power battery. The effective energy utilization rate of the entire power system is achieved by controlling and adjusting the engine load. In this mode, the control state of each assembly is as follows: engine driving, generator generating electricity, front drive motor off, rear drive motor driving, clutch engaged, and power battery charging and discharging.

[0084] Figure 13This is a schematic diagram of the hybrid vehicle powertrain system in energy recovery mode according to one optional embodiment of the present invention. When the vehicle is braking, the speed is within a certain range (e.g., 15-120 km / h), the gear lever is in D or R gear, the driver depresses the brake pedal, or releases the accelerator without depressing the brake pedal. The battery SOC is below a threshold (e.g., <95%). Based on the braking energy recovery strategy, the recovery torque demand is allocated, and energy recovery can be performed through the front drive motor or the rear drive motor. At this time, the powertrain system is controlled to perform braking energy recovery. In this mode, the control states of each assembly are: engine off, generator off, front motor generating electricity, rear motor generating electricity, clutch disengaged, and power battery charging.

[0085] Figure 14 This is a schematic diagram of the hybrid vehicle powertrain system in a stop-start mode according to one optional embodiment of the present invention. The control method is as follows: When the vehicle speed is 0, the start-stop function is triggered, the battery SOC is greater than a threshold (e.g., >35%), the front-drive motor torque capacity meets the starting requirements, the engine coolant temperature is low, or the engine requests to start, or the air conditioning requires heating or defrosting / defogging. If the driver engages D or R gear, the powertrain system enters a stop-start engine mode, discharging the power battery to the generator, which then drives the engine to start. In this mode, the control status of each assembly is as follows: engine starts, generator drives, front-drive motor stops, rear-drive motor stops, clutch disengages, and power battery discharges.

[0086] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0087] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0088] According to another aspect of the present invention, a control device for a hybrid vehicle with series four-wheel drive is also provided, comprising: an acquisition unit for acquiring wheel-end information, the wheel-end information including at least one of the following: required wheel-end torque and required wheel-end driving force; a first determination unit for determining motor output information based on the wheel-end information, the motor output information including the operating parameter output values ​​of a front-drive motor and the operating parameter output values ​​of a rear-drive motor; a second determination unit for determining the total motor drive power based on the motor output information; a third determination unit for determining the engine output power based on the total motor drive power; a fourth determination unit for determining engine output information based on the engine output power, the engine output information including the operating parameter output values ​​of the engine; a fifth determination unit for generating a target control command based on the motor output information and the engine output information; and a control unit for controlling the motor and engine output target power of the target vehicle based on the target control command.

[0089] According to another aspect of the present invention, a computer-readable storage medium is also provided, wherein a computer program is stored therein, and the computer program is configured to execute the above-described method when it is run.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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 is only a logical functional division, and in actual implementation, there may be other division methods. For example, 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.

[0094] 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 network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0095] 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.

[0096] 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.

[0097] 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 series four-wheel drive system in a hybrid vehicle, characterized in that the method... include: Obtain wheel end information, which includes at least one of the following: required torque at the wheel end, required driving force at the wheel end; Based on the wheel end information, the motor output information is determined, which includes the operating parameter output values ​​of the front drive motor and the operating parameter output values ​​of the rear drive motor. The total driving power of the motor is determined based on the motor output information; The engine output power is determined based on the total power of the motor drive. Engine output information is determined based on the engine output power, and the engine output information includes the output values ​​of the engine's operating parameters. Generate target control commands based on the motor output information and the engine output information; Based on the target control command, control the target vehicle's motor and engine to output the target power; Determining the engine output power based on the total power of the motor drive includes: The generator output power is determined based on the total power of the motor drive. The engine output power is determined based on the generator output power. Determining the generator output power based on the total power of the motor drive includes: Obtain the generator's power generation efficiency; The output power of the generator is calculated as the quotient of the total power of the motor drive and the power generation efficiency. Determining the engine output power based on the generator output power includes: Obtain engine efficiency; The engine output power is calculated as the quotient of the generator output power and the engine efficiency.

2. The method according to claim 1, characterized in that, Determining engine output information based on the engine output power includes: Obtain the universal characteristic curve of the engine; Based on the engine output power, the optimal specific fuel consumption under the engine output power is obtained by looking up the value on the engine universal characteristic curve. The engine output information is determined based on the optimal specific fuel consumption and the engine output power.

3. The method according to claim 1, characterized in that, Obtain wheel end information, including: Obtain vehicle status information, which includes at least: vehicle speed; The wheel end information is determined based on the vehicle status information.

4. The method according to claim 3, characterized in that, The method further includes: Detect whether the target vehicle is in series four-wheel drive mode; If so, obtain the vehicle status information.

5. A control device for a hybrid vehicle's series four-wheel drive system, characterized in that, The control device includes: An acquisition unit is used to acquire wheel end information, wherein the wheel end information includes at least one of the following: required torque at the wheel end, required driving force at the wheel end; The first determining unit is used to determine motor output information based on the wheel end information, wherein the motor output information includes the operating parameter output values ​​of the front drive motor and the operating parameter output values ​​of the rear drive motor. The second determining unit is used to determine the total driving power of the motor based on the motor output information; The third determining unit is used to determine the engine output power based on the total power of the motor drive; The fourth determining unit is used to determine engine output information based on the engine output power, wherein the engine output information includes the output values ​​of the engine's operating parameters; The fifth determining unit is used to generate target control commands based on the motor output information and the engine output information; The control unit is used to control the target vehicle's motor and engine to output the target power based on the target control command; Determining the engine output power based on the total power of the motor drive includes: The generator output power is determined based on the total power of the motor drive. The engine output power is determined based on the generator output power. Determining the generator output power based on the total power of the motor drive includes: Obtain the generator's power generation efficiency; The output power of the generator is calculated as the quotient of the total power of the motor drive and the power generation efficiency. Determining the engine output power based on the generator output power includes: Obtain engine efficiency; The engine output power is calculated as the quotient of the generator output power and the engine efficiency.

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 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.

Images