Multi-mode motor torque distribution method and system

Abstract

The invention relates to the technical field of motors, in particular to a multi-mode motor torque distribution method and system, and the method comprises the steps: constructing an economical efficiency control module and a dynamic performance control module based on a hierarchical control architecture based on a front-axle dual-motor and rear-axle single-motor drive system; the driving intention of the driver is calculated according to the opening degree of an accelerator pedal of the driver, if the driving intention is within the standard range of an economical efficiency control module, the optimal torque distribution coefficient is obtained by minimizing instantaneous energy consumption power, and the reference torque of a rear axle motor and the reference torque of a front axle motor are obtained; if the driving intention is within the standard range of the dynamic property control module, based on a preset fuzzy control algorithm, the compensation torque of a front axle motor and the compensation torque of a rear axle motor are calculated according to the vehicle speed and the opening change rate of an accelerator pedal, the compensation torque is superposed to the reference torque of the front axle motor and the reference torque of the rear axle motor respectively, and a final driving torque instruction is obtained; the balance problem of the four-wheel drive multi-motor electric vehicle between economical efficiency and dynamic performance is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular, to a multi-mode motor torque distribution method and system. Background Art

[0002] With the intensification of the global energy and environmental crises, traditional fuel vehicles face challenges due to the large consumption of fossil fuels, and electric vehicles have seen rapid development in improving energy conservation and environmental protection technologies. Four-wheel drive multi-motor electric vehicles have the advantages of flexible improved structures, convenient layouts, and precise motor control. However, multi-motor electric vehicles have problems in driving force distribution and multi-motor coordinated control, which directly affect parameters, dynamic performance, and stability. Therefore, optimizing the drive control strategy has become the key to improving their performance.

[0003] However, existing research mainly optimizes the driving force distribution of multi-motor electric vehicles through model-based or efficiency-based mapping methods. The physical model method establishes an efficiency loss model based on the physical characteristics of the motor and the controller, optimizes the transmission distribution to improve energy utilization efficiency, and has high computational complexity and real-time physical deviation; the efficiency mapping method optimizes the torque distribution through motor efficiency data. For four-wheel drive multi-motor electric vehicles, existing strategies mainly focus on dynamic performance optimization, ignoring the economic requirements under urban driving conditions, and having insufficient dynamic response tests under high power demands (such as starting or rapid acceleration). There is an urgent need for a multi-mode drive optimization control strategy that takes into account both economy and dynamic performance. Summary of the Invention

[0004] In view of the above technical problems, the present invention provides a multi-mode motor torque distribution method and system, which solves the balance problem between economy and dynamic performance of four-wheel drive multi-motor electric vehicles, and optimizes the instantaneous queue and dynamic response through a hierarchical control architecture.

[0005] Other features and advantages of the present disclosure will become apparent from the following detailed description, or be learned in part through the practice of the present disclosure.

[0006] According to one aspect of the present invention, a multi-mode motor torque distribution method is proposed, and the method includes:

[0007] Based on a drive system with two motors on the front axle and one motor on the rear axle, an economic control module and a dynamic performance control module are constructed based on a hierarchical control architecture;

[0008] Calculate the driver's driving intention based on the opening of the driver's accelerator pedal. If the driving intention is within the standard range of the economy control module, calculate the instantaneous energy consumption power of the front and rear axle motors according to the current vehicle speed, initial required torque, and motor efficiency. Using the torque distribution coefficient of the rear axle motor as the optimization variable, obtain the optimal torque distribution coefficient by minimizing the instantaneous energy consumption power. Determine the reference torque distribution of the front axle motor and the rear axle motor according to the optimal torque distribution coefficient, and distribute the total required torque of the vehicle to the rear axle motor and the front axle motor to obtain the reference torque of the rear axle motor and the reference torque of the front axle motor;

[0009] If the driving intention is within the standard range of the power control module, based on a preset fuzzy control algorithm, calculate the compensation torques of the front axle motor and the rear axle motor according to the vehicle speed and the change rate of the accelerator pedal opening, and superimpose the compensation torques onto the reference torques of the front axle motor and the rear axle motor respectively to obtain the final drive torque commands of the front axle motor and the rear axle motor.

[0010] Furthermore, the value range of the torque distribution coefficient of the rear axle motor is 0 - 1. When it is equal to 1, only the rear axle motor provides the driving torque; when it is equal to 0, only the front axle motor provides the driving torque; when it is greater than 0 and less than 1, both the front axle motor and the rear axle motor provide the driving torque.

[0011] Furthermore, the optimization objective of the economy control module is to minimize the instantaneous energy consumption power; the instantaneous energy consumption power is equal to the sum of the mechanical power and the loss power output by the front axle motor and the rear axle motor.

[0012] Furthermore, when minimizing the instantaneous energy consumption power, it includes:

[0013] Determine the torque load coefficient L according to the throttle pedal opening d , L d = f(α ap ), where α ap is the percentage of the throttle pedal opening;

[0014] Calculate the initial required torque T i (L d , n i ) of each motor, where:

[0015] i = 0 represents the rear axle motor, i = 1, 2 represent the left and right front axle motors, T imax is the peak torque of the i-th motor, n 0i is the reference speed, n i is the speed of the i-th motor;

[0016] Calculate the initial required torque T req ,

[0017] Calculate the total mechanical power P of each motor mech , where:

[0018] P mech,i is the mechanical power of a single motor; ω i is the standard speed of the i-th motor, in radians per second,

[0019] Calculate the total power of each motor. The total power of each motor is the sum of the mechanical power and the loss power of the motor, and we get: P t is the total power of each motor, P loss is the total loss power of each motor, P loss,i is the loss power of a single motor, P loss,i The calculation is as follows:

[0020]

[0021] T i0 and ω i0 are the torque and speed corresponding to the minimum data point of the i-th motor's map characteristics respectively, and η i (T i , ω i ) is the efficiency of the i-th motor at the specified speed and torque, which is obtained through the motor calibration test;

[0022] Take the torque distribution coefficient of the rear axle motor as the optimization variable and the total power of each motor as the objective function:

[0023]

[0024] κ is the torque distribution coefficient of the rear axle motor, i f and i r represent the front and rear transmission ratios respectively, and P loss,i (κ) is the loss power under the condition of κ;

[0025] Minimize the objective function of the total power of each motor to achieve the minimum instantaneous energy consumption power.

[0026] Furthermore, when minimizing the instantaneous energy consumption power, it also includes:

[0027] Establish torque constraint conditions to ensure that the torque assigned to each motor does not exceed the maximum limit of its external characteristic curve:

[0028]

[0029] where, T 0max(ω0) is the maximum external characteristic torque of the rear axle motor at a vehicle speed of ω0; T 1max (ω1) is the maximum external characteristic torque of the front axle motor at a vehicle speed of ω1;

[0030] Establish wheel adhesion constraint conditions to ensure that the adhesion of each axle wheel is not greater than the road adhesion:

[0031]

[0032] Among them, and are the adhesion coefficients of the front and rear wheels respectively; a and b are the distances from the center of mass to the front and rear axles respectively; h g is the height of the center of mass; q is the equivalent road gradient; is the road adhesion coefficient;

[0033] Based on the objective function of the total power of each motor, the wheel adhesion constraint conditions, and the torque constraint conditions, the minimization model of the instantaneous energy consumption power is obtained as:

[0034]

[0035] Solve the minimization model based on the Lagrangian relaxation variable method to obtain the optimal torque distribution coefficient.

[0036] Furthermore, the fuzzy control algorithm includes:

[0037] Collect and analyze vehicle operation and driving control data;

[0038] Select the vehicle speed and the change rate of the throttle pedal opening as the input variables of the fuzzy control algorithm, and select the compensation torque of the front and rear axle motors as the output variables;

[0039] Define the domain and fuzzy subsets of the input variables. The domain of its speed is [0, 160], and its fuzzy subsets are {small, medium, slightly high, high}. The domain of the change rate of the throttle pedal opening is [30, 200], and its fuzzy subsets are {small, medium, large};

[0040] Define the domain and fuzzy subsets of the output variables: the domain of the compensation torque of the front axle motor is [0, 12], the domain of the compensation torque of the rear axle motor is [0, 20], and the fuzzy subsets of the output variables are all {small, medium, large};

[0041] Based on the dynamic requirements under vehicle start and rapid acceleration conditions, analyze the actual demand torque change law of the reference vehicle; formulate a fuzzy rule table for the front and rear axle motors, and determine different torque compensation amounts according to the fuzzy membership degrees of the input variables under different working conditions;

[0042] Further, based on vehicle ride comfort, the acceleration change rate J caused by the compensating torque is restricted to be less than 10 m / s 3 , and the compensating torque satisfies: where ΔT is the compensating torque, Δt is the motor torque response time, J is the acceleration change rate, m is the vehicle mass, R is the tire radius, i is the transmission ratio, and η T is the drive system efficiency.

[0043] According to a second aspect of the present disclosure, there is provided a multi-mode motor torque distribution system, the system comprising:

[0044] A modeling module for constructing an economy control module and a power control module based on a hierarchical control architecture for a drive system with dual motors on the front axle and a single motor on the rear axle;

[0045] A low-speed distribution module for calculating the driver's driving intention according to the opening of the driver's accelerator pedal. If the driving intention is within the standard range of the economy control module, calculating the instantaneous energy consumption power of the front and rear axle motors according to the current vehicle speed, the initial required torque, and the motor efficiency, and using the torque distribution coefficient of the rear axle motor as an optimization variable, obtaining the optimal torque distribution coefficient by minimizing the instantaneous energy consumption power, determining the reference torque distribution of the front axle motor and the rear axle motor according to the optimal torque distribution coefficient, and distributing the total torque required by the vehicle to the rear axle motor and the front axle motor to obtain the rear axle motor reference torque and the front axle motor reference torque;

[0046] A high-speed distribution module for, when the driving intention is within the standard range of the power control module, calculating the compensating torques of the front axle motor and the rear axle motor based on a preset fuzzy control algorithm according to the vehicle speed and the acceleration pedal opening change rate, and superimposing the compensating torques onto the reference torques of the front axle motor and the rear axle motor respectively to obtain the final drive torque commands of the front axle motor and the rear axle motor.

[0047] The technical solution of the present disclosure has the following beneficial effects:

[0048] By proposing a multi-mode drive optimization control method applicable to four-wheel drive multi-motor electric vehicles, the coordinated optimization between the economy and power of the vehicle is achieved. Under low-speed or low-power demand conditions, by optimizing the torque distribution ratio of the front and rear motors, the instantaneous energy consumption power of the motors is reduced, enabling the motors to operate in the high-efficiency region, significantly improving the energy utilization efficiency and endurance of the vehicle; under high-power demand conditions such as starting or rapid acceleration, through a torque compensation strategy based on fuzzy control, the driver's demands are responded to in a timely manner, enhancing the vehicle's dynamic performance and acceleration ability. At the same time, the influence of the vehicle's acceleration change rate on ride comfort is fully considered, and by restricting the torque change, the vehicle not only has excellent dynamic response ability but also takes into account the ride comfort of the driver and passengers. Brief Description of the Drawings

[0049] Figure 1 It is a flowchart of a multi - mode motor torque distribution method in an embodiment of this specification;

[0050] Figure 2 It is a structural block diagram of a multi - mode motor torque distribution system in an embodiment of this specification;

[0051] Figure 3 It is a terminal device for implementing a multi - mode motor torque distribution method in an embodiment of this specification;

[0052] Figure 4 It is a computer - readable storage medium storing a multi - mode motor torque distribution method in an embodiment of this specification. Detailed Embodiments

[0053] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be more complete and comprehensive, and will fully convey the concept of the example embodiments to those skilled in the art. The features, structures, or characteristics described can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the embodiments of the present disclosure. However, those skilled in the art will realize that one or more of the specific details can be omitted in practicing the technical solutions of the present disclosure, or other methods, components, devices, steps, etc. can be adopted. In other cases, well - known technical solutions are not shown or described in detail to avoid obscuring the various aspects of the present disclosure.

[0054] In addition, the accompanying drawings are only schematic diagrams of the present disclosure. The same reference numerals in the drawings denote the same or similar parts, and thus their repeated description will be omitted. Some of the block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0055] The present invention provides a multi - mode motor torque distribution method for a product. Referring to Figure 1 As shown, it is a schematic flowchart of a multi - mode motor torque distribution method provided by an embodiment of the present invention. This method can be applied to electronic devices such as personal computers and servers. This method can be executed by a device, which can be implemented by software and / or hardware. Specifically, this method can include the following steps S101 - S103::

[0056] In step S101, based on the drive system with dual motors on the front axle and a single motor on the rear axle, an economy control module and a power performance control module are constructed based on a hierarchical control architecture.

[0057] Among them, in this drive system, the rear axle motor serves as the main drive source, with a single motor structure, suitable for operating under low-speed and stable conditions, having high efficiency and economy; the front axle motors are two motors with relatively small power, arranged on the front axle, suitable for providing additional power to enhance acceleration and climbing performance. To coordinate economy and power performance, a hierarchical control architecture is adopted to design the drive control strategy. This architecture is divided into two layers from top to bottom. The upper layer is for driving intention recognition and mode determination, and the lower layer is for the execution of the corresponding control modules; in the upper layer, the input is the driving intention, which is determined by the accelerator pedal opening of the driver, its change rate, vehicle speed, etc., and the output is whether it is currently in an economy condition (low-speed cruise, light load) or a power performance condition (starting, rapid acceleration, high-speed cruise). The judgment logic is: when the accelerator pedal opening is small and the vehicle speed is low, it enters economy control; when the accelerator pedal opening rises rapidly or the vehicle speed is high, it switches to power performance control. In the lower layer, according to the decision of the upper layer, the corresponding economy control module or power performance control module is triggered, and then economy control or power performance control (response speed is prioritized) is carried out respectively.

[0058] In step S102, the driving intention of the driver is calculated according to the accelerator pedal opening of the driver. If the driving intention is within the standard range of the economy control module, according to the current vehicle speed, initial required torque, and motor efficiency, the instantaneous energy consumption power of the front and rear axle motors is calculated, and with the torque distribution coefficient of the rear axle motor as the optimization variable, the optimal torque distribution coefficient is obtained by minimizing the instantaneous energy consumption power. According to the optimal torque distribution coefficient, the reference torque distribution of the front axle motor and the rear axle motor is determined, and the total torque required by the vehicle is distributed to the rear axle motor and the front axle motor to obtain the reference torque of the rear axle motor and the reference torque of the front axle motor.

[0059] In step S103, if the driving intention is within the standard range of the power performance control module, based on a preset fuzzy control algorithm, the compensation torques of the front axle motor and the rear axle motor are calculated according to the vehicle speed and the change rate of the accelerator pedal opening, and the compensation torques are respectively superimposed on the reference torques of the front axle motor and the rear axle motor to obtain the final drive torque commands of the front axle motor and the rear axle motor.

[0060] Among them, specifically in step S102, the optimization objective of the economy control module is to minimize the instantaneous energy consumption power; the instantaneous energy consumption power is equal to the sum of the mechanical power and the loss power output by the front axle motor and the rear axle motor.

[0061] When minimizing the instantaneous energy consumption power, it includes:

[0062] Determine the torque load coefficient L according to the throttle pedal opening d , L d = f(α ap ), where α ap is the percentage of the throttle pedal opening. Among them, the command for electric vehicle drive control comes from the driver's operation of the throttle pedal, and the drive torque command is mainly converted from the throttle pedal opening. Therefore, the torque load coefficient of the original drive is related to the throttle pedal opening.

[0063] Determine the torque load coefficient according to the throttle pedal opening, and calculate the initial required torque T of each motor i (L d , n i ), where:[[]]

[0064] i = 0 represents the rear axle motor, i = 1, 2 represent the left and right front axle motors, T imax is the peak torque of the i-th motor, n 0i is the reference speed, n i is the speed of the i-th motor.

[0065] Therefore, at a certain throttle pedal opening, the initial required torque T of the vehicle can be calculated req , where:[[]]

[0066]

[0067] Next, calculate the total mechanical power P of each motor mech , where:[[]]

[0068] P mech,i is the mechanical power of a single motor; ω i is the standard speed of the i-th motor, in radians per second,[[]]

[0069] Calculate the total power of each motor. The total power of each motor is the sum of the mechanical power and the loss power of the motor, and we get: P t is the total power of each motor, P loss is the total loss power of each motor, P loss,i is the loss power of a single motor. The motor loss power is mainly composed of iron loss, copper loss and friction loss. The motor loss energy is dissipated into the air in the form of heat. In the motor mode, the motor loss power P loss,i is calculated as:

[0070]

[0071] T i0 and ωi0 are the torque and rotational speed corresponding to the minimum data point of the i-th motor map characteristic, respectively, η i (T i , ω i ) is the efficiency of the i-th motor at the specified rotational speed and torque, which is obtained through the motor calibration test;

[0072] Taking the torque distribution coefficient of the rear axle motor as the optimization variable and the total power of each motor as the objective function:

[0073]

[0074] k is the torque distribution coefficient of the rear axle motor. The value range of the torque distribution coefficient of the rear axle motor is 0 - 1. When it is equal to 1, only the rear axle motor provides the driving torque; when it is equal to 0, only the front axle motor provides the driving torque; when it is greater than 0 and less than 1, both the front axle motor and the rear axle motor provide the driving torque., i f and i r represent the front and rear transmission ratios respectively, P loss,i (κ) is the loss power under the condition of κ;

[0075] Minimize the objective function of the total power of each motor to achieve the minimization of the instantaneous energy consumption power.

[0076] As a supplement, when minimizing the instantaneous energy consumption power, it also includes:

[0077] Establish torque constraint conditions to ensure that the torque assigned to each motor does not exceed the maximum limit of its external characteristic curve:

[0078]

[0079] Among them, T 0max (ω0) is the maximum external characteristic torque of the rear axle motor when the vehicle speed is ω0; T 1max (ω1) is the maximum external characteristic torque of the front axle motor when the vehicle speed is ω1;

[0080] Establish wheel adhesion constraint conditions to ensure that the wheel adhesion of each axle is not greater than the road adhesion:

[0081]

[0082] Among them, and are the adhesion coefficients of the front and rear wheels respectively; a and b are the distances from the center of mass to the front and rear axles respectively; h g is the height of the center of mass; q is the equivalent road gradient; is the road adhesion coefficient;

[0083] Based on the objective function of the total power of each motor, the wheel adhesion constraint condition, and the torque constraint condition, the minimization model of the instantaneous energy consumption power is obtained as follows:

[0084]

[0085] Solving the minimization model based on the Lagrangian relaxation variable method can obtain the optimal torque distribution coefficient.

[0086] Specifically, in step S103, the fuzzy control algorithm includes:

[0087] Collect and analyze vehicle operation and driving control data. The collected vehicle operation and driving control data can be data of familiar drivers.

[0088] Select the vehicle speed and the change rate of the throttle pedal opening as the input variables of the fuzzy control algorithm, and select the compensation torques of the front and rear axle motors as the output variables;

[0089] Define the domain and fuzzy subsets of the input variables. The domain of its speed is [0, 160], and its fuzzy subsets are {small, medium, slightly high, high}. The domain of the change rate of the throttle pedal opening is [30, 200], and its fuzzy subsets are {small, medium, large};

[0090] Define the domain and fuzzy subsets of the output variables: the domain of the compensation torque of the front axle motor is [0, 12], the domain of the compensation torque of the rear axle motor is [0, 20], and the fuzzy subsets of the output variables are all {small, medium, large};

[0091] Based on the dynamic requirements under vehicle startup and rapid acceleration conditions, analyze the actual demand torque change law of the reference vehicle; formulate a fuzzy rule table for the front and rear axle motors, and determine different torque compensation amounts according to the fuzzy membership degrees of the input variables under different working conditions.

[0092] As a supplement, since the sudden change of the driving torque has a greater impact on the ride comfort of the vehicle, the limitation of the jerk should be fully considered when determining the maximum value of the compensation torque to avoid the decrease of ride comfort caused by excessive or unreasonable torque compensation. For example, the greater the acceleration change rate, the greater the jerk. Therefore, the acceleration change rate J caused by the compensation torque can be limited to be less than 10 m / s 3 , and the compensation torque satisfies: where ΔT is the compensation torque, Δt is the motor torque response time, J is the acceleration change rate, m is the vehicle mass, R is the tire radius, i is the transmission ratio, and η T is the driving system efficiency.

[0093] Based on the same idea, such as Figure 2As shown, it is a structural block diagram of a multi-mode motor torque distribution system provided by an embodiment of the present invention. The system includes:

[0094] A modeling module 201, configured to build an economy control module and a power performance control module based on a drive system with dual motors on the front axle and a single motor on the rear axle, based on a hierarchical control architecture;

[0095] A low-speed distribution module 202, configured to calculate the driving intention of the driver according to the opening of the driver's accelerator pedal. If the driving intention is within the standard range of the economy control module, calculate the instantaneous energy consumption power of the front and rear axle motors according to the current vehicle speed, initial required torque, and motor efficiency, and use the torque distribution coefficient of the rear axle motor as the optimization variable. Obtain the optimal torque distribution coefficient by minimizing the instantaneous energy consumption power, determine the reference torque distribution of the front axle motor and the rear axle motor according to the optimal torque distribution coefficient, and distribute the total torque required by the vehicle to the rear axle motor and the front axle motor to obtain the rear axle motor reference torque and the front axle motor reference torque;

[0096] A high-speed distribution module 203, configured to, when the driving intention is within the standard range of the power performance control module, calculate the compensation torques of the front axle motor and the rear axle motor based on a preset fuzzy control algorithm according to the vehicle speed and the change rate of the accelerator pedal opening, and superimpose the compensation torques on the reference torques of the front axle motor and the rear axle motor respectively to obtain the final drive torque commands of the front axle motor and the rear axle motor.

[0097] The specific details in the above system have been described in detail in the implementation manner of the method part. The undisclosed detailed content can be referred to the implementation manner content of the method part, and thus will not be elaborated here.

[0098] By proposing a multi-mode drive optimization control method applicable to four-wheel drive multi-motor electric vehicles, the present system realizes the coordinated optimization between the economy and power performance of the vehicle. Under low-speed or low-power demand conditions, by optimizing the torque distribution ratio of the front and rear motors, the instantaneous energy consumption power of the motors is reduced, enabling the motors to operate in the high-efficiency region, significantly improving the energy utilization efficiency and cruising range of the vehicle; under high-power demand conditions such as starting or rapid acceleration, through a torque compensation strategy based on fuzzy control, the driver's demands are promptly responded to, enhancing the vehicle's dynamic performance and acceleration ability. At the same time, the influence of the vehicle's acceleration change rate on ride comfort is fully considered, and by constraining the torque change, the vehicle not only has excellent dynamic response ability but also takes into account ride comfort.

[0099] Based on the same idea, the embodiment of the present specification also provides a multi-mode motor torque distribution device, as Figure 4 shown.

[0100] The multi-mode motor torque distribution device can be a terminal device or a server provided by the above embodiments.

[0101] The multi-mode motor torque distribution device may vary significantly due to different configurations or performances, and may include one or more processors 301, a memory 302, and a bus. One or more application programs or data may be stored in the memory 302. Among them, the memory 302 may include a readable medium in the form of a volatile storage unit, such as a random access storage unit (RAM) and / or a cache storage unit, that is, for example, a pluggable mobile hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. equipped on an electronic device, and may further include a read-only storage unit. The application programs stored in the memory 302 may include one or more program modules (not shown in the figure). Such program modules include, but are not limited to: an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include the implementation of a network environment. Further, the processor 301 may be configured to communicate with the memory 302 and execute a series of computer-executable instructions in the memory 302 on the multi-mode motor torque distribution device. The multi-mode motor torque distribution device may also include one or more power supplies 303, one or more wired or wireless network interfaces 304, one or more I / O interfaces (input / output interfaces) 305, communicate with one or more external devices 306 (such as a keyboard), and may also communicate with one or more devices that enable a user to interact with the device, and / or communicate with any device that enables the device to communicate with one or more other computing devices (such as a router, a network switch, etc.). Such communication may be performed through the I / O interface 305. And the device may also communicate with one or more networks (such as a local area network (LAN)) through the wired or wireless interface 304.

[0102] In some embodiments, the processor 301 may be composed of an integrated circuit. For example, it may be composed of a single packaged integrated circuit, or may be composed of multiple packaged integrated circuits with the same or different functions, including a combination of one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and various control chips. The processor 301 is the control core (Control Unit) of the electronic device, connecting various components of the entire electronic device through various interfaces and circuits, and executing various functions and processing data of the processing device by running or executing programs or modules stored in the memory 11 (such as the motor torque distribution program of the product in multiple modes) and calling the data stored in the memory.

[0103] The bus may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. This bus can be divided into an address bus, a data bus, a control bus, etc. The bus is configured to enable connection and communication between the memory 302 and at least one processor 301, etc.

[0104] The power supply can be logically connected to the at least one processor 301 through a power management device, so as to implement functions such as charging management, discharging management, and power consumption management through the power management device. The power supply may also include any components such as one or more DC or AC power supplies, a recharge device, a power failure detection circuit, a power converter or inverter, and a power status indicator. The electronic device 1 may also include various sensors, a Bluetooth module, a Wi-Fi module, etc., which will not be elaborated here.

[0105] Optionally, the processing device may further include a user interface. The user interface may be a display (Display). Optionally, the user interface may also be a standard wired interface or a wireless interface. Optionally, in some embodiments, the display may be an LED display, a liquid crystal display, a touch liquid crystal display, and an OLED

[0106] (Organic Light-Emitting Diode) toucher, etc. Among them, the display may also be appropriately referred to as a display screen or a display unit, which is used to display the information processed in the electronic device 1 and to display a visual user interface

[0107] Figure 3 Only a multi-mode motor torque distribution device with components is shown. Those skilled in the art can understand thatFigure 3 The structures shown do not constitute a limitation on the multi-mode motor torque distribution device, and may include fewer or more components than shown, or combine certain components, or have different component arrangements.

[0108] Specifically, in this embodiment, the multi-mode motor torque distribution device includes a memory and one or more programs, where one or more programs are stored in the memory, and one or more programs may include one or more modules, and each module may include a series of computer-executable instructions for the multi-mode motor torque distribution device, and is configured to be executed by one or more processors. The one or more programs include computer-executable instructions for performing the following:

[0109] Based on a drive system with dual motors on the front axle and a single motor on the rear axle, an economy control module and a power performance control module are constructed based on a hierarchical control architecture;

[0110] Calculate the driver's driving intention according to the opening of the driver's accelerator pedal. If the driving intention is within the standard range of the economy control module, calculate the instantaneous energy consumption power of the front and rear axle motors according to the current vehicle speed, initial required torque, and motor efficiency, and use the torque distribution coefficient of the rear axle motor as the optimization variable. Obtain the optimal torque distribution coefficient by minimizing the instantaneous energy consumption power, determine the reference torque distribution of the front axle motor and the rear axle motor according to the optimal torque distribution coefficient, and distribute the total torque required by the vehicle to the rear axle motor and the front axle motor to obtain the reference torque of the rear axle motor and the reference torque of the front axle motor;

[0111] If the driving intention is within the standard range of the power performance control module, based on a preset fuzzy control algorithm, calculate the compensation torques of the front axle motor and the rear axle motor according to the vehicle speed and the change rate of the accelerator pedal opening, and superimpose the compensation torques onto the reference torques of the front axle motor and the rear axle motor respectively to obtain the final drive torque commands of the front axle motor and the rear axle motor.

[0112] Based on the same idea, the exemplary embodiments of the present invention also provide a computer-readable storage medium, on which a program product capable of implementing the above method of this specification is stored. In some possible implementation manners, various aspects of the present disclosure can also be implemented in the form of a program product, which includes program code. When the program product runs on a terminal device, the program code is used to cause the terminal device to execute the steps according to various exemplary embodiments of the present disclosure described in the above "Exemplary Method" section of this specification.

[0113] Reference Figure 4As shown, a program 400 for implementing the above method according to an exemplary embodiment of the present disclosure is described. It can be in the form of a portable compact disc read-only memory (CD-ROM), include program code, and can run on a terminal device such as a personal computer. However, the program product of the present disclosure is not limited to this. In this document, a readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0114] The program product can adopt any combination of one or more readable media. The readable media can be a readable signal medium or a readable storage medium. A readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (non-exhaustive list) of the readable storage medium include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0115] A computer-readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, which carries the readable program code. Such a propagated data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The readable signal medium can also be any readable medium other than the readable storage medium, which can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0116] The program code for performing the operations of the present disclosure can be written in any combination of one or more programming languages, including object-oriented programming languages such as Java, C++, CSS, HTML, etc., and also including conventional procedural programming languages such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computing device, partially on the user's device, executed as a stand-alone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user's computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., by connecting through an Internet service provider via the Internet).

[0117] Those skilled in the art can easily understand from the description of the above embodiments that the exemplary embodiments described herein can be implemented by software or by a combination of software and necessary hardware. Therefore, the technical solutions according to the embodiments of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, and includes several instructions to enable a computing device (such as a personal computer, a server, a terminal device, or a network device, etc.) to execute the method according to the exemplary embodiments of the present disclosure.

[0118] In addition, the above-mentioned drawings are only schematic illustrations of the processes included in the method according to the exemplary embodiments of the present disclosure, rather than for limiting purposes. It is easy to understand that the processes shown in the above-mentioned drawings do not indicate or limit the chronological order of these processes. Additionally, it is also easy to understand that these processes can be executed synchronously or asynchronously, for example, in multiple modules.

[0119] It should be noted that although several modules or units of devices for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to the exemplary embodiments of the present disclosure, the features and functions of the two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0120] Those skilled in the art will readily think of other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common general knowledge or conventional technical means in the technical field not disclosed in the present disclosure. The specification and embodiments are only regarded as exemplary, and the true scope and spirit of the present disclosure are pointed out by the claims.

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

Claims

1. A multi-mode motor torque distribution method, characterized in that, The method includes: Based on a drive system with dual motors on the front axle and a single motor on the rear axle, an economy control module and a power control module are constructed based on a hierarchical control architecture; Calculate the driver's driving intention according to the opening degree of the accelerator pedal of the driver. If the driving intention is within the standard range of the economy control module, calculate the instantaneous energy consumption power of the front and rear axle motors according to the current vehicle speed, the initial required torque, and the motor efficiency, and use the torque distribution coefficient of the rear axle motor as the optimization variable. Obtain the optimal torque distribution coefficient by minimizing the instantaneous energy consumption power, determine the reference torque distribution of the front axle motor and the rear axle motor according to the optimal torque distribution coefficient, and distribute the total torque required by the vehicle to the rear axle motor and the front axle motor to obtain the rear axle motor reference torque and the front axle motor reference torque; If the driving intention is within the standard range of the power control module, based on a preset fuzzy control algorithm, calculate the compensation torques of the front axle motor and the rear axle motor according to the vehicle speed and the change rate of the accelerator pedal opening degree, and superimpose the compensation torques on the reference torques of the front axle motor and the rear axle motor respectively to obtain the final drive torque commands of the front axle motor and the rear axle motor.

2. The multi-mode motor torque distribution method according to claim 1, characterized in that, The value range of the torque distribution coefficient of the rear axle motor is 0-1. When it is equal to 1, only the rear axle motor provides the driving torque; when it is equal to 0, only the front axle motor provides the driving torque; when it is greater than 0 and less than 1, the front axle motor and the rear axle motor provide the driving torque simultaneously.

3. The multi-mode motor torque distribution method according to claim 1, wherein, The optimization goal of the economy control module is to minimize the instantaneous energy consumption power; the instantaneous energy consumption power is equal to the sum of the mechanical power and the loss power output by the front axle motor and the rear axle motor.

4. The multi-mode motor torque distribution method according to claim 1, wherein When minimizing the instantaneous energy consumption power, it includes: Determine the torque load coefficient L based on the throttle pedal opening d , L d = f(α ap ), where α ap is the throttle pedal opening percentage; Calculate the initial required torque T of each motor i (L d , n i ), where: i = 0, 1, 2, where i = 0 represents the rear - axle motor, and i = 1, 2 represent the left and right front - axle motors, T imax is the peak torque of the i - th motor, n 0i is the reference speed, n i is the speed of the i - th motor; Calculate the initial required torque T of the vehicle req , i = 0, 1, 2; Calculate the total mechanical power P of each motor mech , where: i = 0, 1, 2; P mech,i is the mechanical power of a single motor; ω i is the standard speed of the i-th motor, in radians per second, i = 0, 1, 2; Calculate the total power of each motor. The total power of each motor is the sum of the mechanical power and the loss power of the motor, and we get: P t is the total power of each motor, P loss is the total loss power of each motor, P loss,i is the loss power of a single motor, P loss,i The calculation is as follows: T i0 and ω i0 are the torque and rotational speed corresponding to the minimum data point of the motor map characteristics of the i-th motor, respectively. η i (T i , ω i ) is the efficiency of the i-th motor at the specified rotational speed and torque, which is obtained through the motor calibration test; Using the torque distribution coefficient of the rear axle motor as the optimization variable and the total power of each motor as the objective function: κ is the torque distribution coefficient of the rear axle motor, i f and i r represent the front and rear transmission ratios respectively, P loss,i (κ) is the power loss under the condition of κ; Minimize the objective function of the total power of each motor to achieve minimizing the instantaneous energy consumption power.

5. The multi-mode motor torque distribution method according to claim 4, wherein When minimizing the instantaneous energy consumption power, it also includes: Establish torque constraint conditions to ensure that the torque allocated to each motor does not exceed the maximum limit of its external characteristic curve: Among them, T 0max (ω0) is the maximum external characteristic torque of the rear axle motor at a vehicle speed of ω0; T 1max (ω1) is the maximum external characteristic torque of the front axle motor at a vehicle speed of ω1; Establish wheel adhesion constraint conditions to ensure that the wheel adhesion of each axle is not greater than the road surface adhesion: wherein, and are the adhesion coefficients of the front and rear wheels respectively; a and b are the distances from the center of mass to the front and rear axles respectively; h g is the height of the center of mass; q is the equivalent road gradient; is the road adhesion coefficient; Based on the objective function of the total power of each motor, the wheel adhesion constraint conditions, and the torque constraint conditions, the minimization model of the instantaneous energy consumption power is obtained as: Solve the minimization model based on the Lagrangian relaxation variable method to obtain the optimal torque distribution coefficient.

6. The multi-mode motor torque distribution method according to claim 1, characterized in that The fuzzy control algorithm includes: Collect and analyze vehicle operation and driving control data; Select the vehicle speed and the change rate of the accelerator pedal opening degree as the input variables of the fuzzy control algorithm, and select the compensation torques of the front and rear axle motors as the output variables; Define the domain and fuzzy subsets of the input variables. The domain of its speed is [0,160], and its fuzzy subsets are {small, medium, slightly high, high}. The domain of the change rate of the accelerator pedal opening degree is [30,200], and its fuzzy subsets are {small, medium, large}; Define the domain and fuzzy subsets of the output variables: the domain of the compensation torque of the front axle motor is [0,12], the domain of the compensation torque of the rear axle motor is [0,20], and the fuzzy subsets of the output variables are all {small, medium, large}; Based on the dynamic requirements under vehicle startup and rapid acceleration conditions, analyze the actual demand torque variation law of the reference vehicle; formulate the fuzzy rule table for the front and rear axle motors, and determine different torque compensation amounts according to the fuzzy membership degrees of the input variables under different working conditions.

7. The multi-mode motor torque distribution method according to claim 1, characterized in that Based on vehicle ride comfort, limit the acceleration change rate J caused by the compensation torque to be less than 10 m / s 3 , and the compensation torque satisfies: where ΔT is the compensation torque, Δt is the motor torque response time, J is the acceleration change rate, m is the vehicle mass, R is the tire radius, i is the transmission ratio, and η T is the drive system efficiency.

8. A multi-mode motor torque distribution system, the system comprising: A modeling module, configured to construct an economy control module and a power control module based on a hierarchical control architecture for a drive system with dual motors on the front axle and a single motor on the rear axle; A low-speed distribution module, configured to calculate the driver's driving intention according to the opening degree of the driver's accelerator pedal. If the driving intention is within the standard range of the economy control module, calculate the instantaneous energy consumption power of the front and rear axle motors according to the current vehicle speed, initial demand torque, and motor efficiency, and use the torque distribution coefficient of the rear axle motor as the optimization variable to obtain the optimal torque distribution coefficient by minimizing the instantaneous energy consumption power. Determine the reference torque distribution of the front axle motor and the rear axle motor according to the optimal torque distribution coefficient, and distribute the total torque required by the vehicle to the rear axle motor and the front axle motor to obtain the reference torque of the rear axle motor and the reference torque of the front axle motor; A high-speed distribution module, configured to, when the driving intention is within the standard range of the power control module, calculate the compensation torques of the front axle motor and the rear axle motor based on a preset fuzzy control algorithm according to the vehicle speed and the change rate of the accelerator pedal opening degree, and superimpose the compensation torques onto the reference torques of the front axle motor and the rear axle motor respectively to obtain the final drive torque commands of the front axle motor and the rear axle motor.

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