Driving method of dual-motor electric drive axle

Abstract

The application provides a driving method of a double-motor electric drive axle, which is suitable for an electric drive axle architecture, and the driving method comprises the following steps: obtaining a target vehicle speed and a target torque; searching for a function relationship linear curve corresponding to the target vehicle speed and the target torque in a preset curve database; obtaining a target driving mode corresponding to the target vehicle speed and the target torque according to a corresponding relationship between the function relationship linear curve and a driving mode; determining a target total rotation speed and a target total efficiency of a first motor and a second motor according to the target vehicle speed; and when the real-time speed of the target vehicle is the target vehicle speed and the sum of the real-time rotation speeds of the first motor and the second motor is the target total rotation speed, switching the operation efficiency of the first motor and the second motor to the target total efficiency, and driving the target vehicle to operate in the target driving mode. The application solves the problem of low use efficiency of the motor due to the singleness of the driving mode and the inflexible motor torque distribution mode in the prior art.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor driving, in particular to a driving method of a dual-motor electric drive axle. BACKGROUND

[0002] Under the background of the rising global environmental protection awareness and energy crisis, new energy vehicles, especially electric vehicles, have become the mainstream direction of the development of the automobile industry. As a core component of electric vehicles, the electric drive axle plays a key role in transmitting power from the power source to the wheel end, and its performance directly affects the power performance, energy efficiency level and driving comfort of the vehicle. The electric drive axle usually includes electric motors, reducers, motor controllers and differentials, and the efficient integration and cooperative work of these components make the electric drive axle a key technology for improving the performance of electric vehicles.

[0003] However, the traditional single-motor electric drive axle design scheme has significant limitations. Due to the high cost of a single high-power motor and the low efficiency under low load conditions, such systems often result in high vehicle energy consumption and unsatisfactory power performance. With the continuous progress of technology, electric drive axles using dual-motor architecture have gradually become a research hotspot. Through the cooperation of two relatively small power motors, not only the system cost is reduced, but also the motors can be more frequently operated in the high-efficiency working area through fine speed ratio configuration, thereby significantly improving the economy and driving experience of the vehicle.

[0004] In the field of dual-motor electric drive axles, planetary gear mechanisms are widely used to achieve flexible coupling and intelligent distribution of power for electric motors. Using a planetary gear mechanism, the first motor and the second motor can be connected or disconnected with different parts of the gear through a clutch. This dynamic connection allows the system to smoothly switch between multiple drive modes to meet different driving conditions and driving needs.

[0005] However, the current dual-motor multi-gear electric drive axle system still has room for improvement. Especially under high-speed driving conditions, due to the single nature of the drive mode and the inflexible motor torque distribution strategy, the power usage efficiency of the motor cannot be optimized, which not only leads to additional energy consumption, but also affects the economy and overall performance of electric vehicles. SUMMARY

[0006] The main purpose of the present application is to provide a driving method of a dual-motor electric drive axle to solve the problem of low motor usage efficiency due to the single nature of the drive mode and the inflexible motor torque distribution method under high-speed driving conditions in the prior art.

[0007] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a driving method of a dual-motor electric drive axle is provided, the driving method is suitable for an electric drive axle architecture, the electric drive axle architecture comprises a first motor and a second motor arranged symmetrically, and further comprises a planetary gear train, an output shaft of the first motor is connected with a sun gear in the planetary gear train, and the sun gear is selectively connected with a planet gear or a ring gear in the planetary gear train to complete gear shifting under the action of a gear shifting mechanism, the driving method comprises:

[0008] During operation of the target vehicle, a target vehicle speed and a target torque of the target vehicle within a predetermined travel distance are obtained, the target torque being the sum of the torques of the first motor and the second motor;

[0009] In a preset curve database, a function relationship linear curve conforming to the target vehicle speed and the target torque is found;

[0010] According to a corresponding relationship between the function relationship linear curve and the driving mode, a driving mode corresponding to the target vehicle speed and the target torque is obtained and marked, and a target driving mode is obtained;

[0011] The target total speed and the target total efficiency of the first motor and the second motor are determined according to the target vehicle speed;

[0012] When the real-time speed of the target vehicle is the target vehicle speed and the sum of the real-time speeds of the first motor and the second motor is the target total speed, the operating efficiency of the first motor and the second motor is switched to the target total efficiency, and the target vehicle is driven to operate in the target driving mode;

[0013] The driving mode includes a single-motor driving mode and a multi-motor driving mode, the single-motor driving mode is a mode in which the first motor or the second motor drives any gear position of the connected transmission, and the multi-motor driving mode is a mode in which the first motor drives any gear position of the connected transmission and the second motor drives any gear position of the connected transmission.

[0014] Further, in the step of finding a function relationship linear curve conforming to the target vehicle speed and the target torque in the preset curve database, the step comprises:

[0015] The preset curve database is constructed, and the preset curve database comprises first function relationship linear curves corresponding to various first sub-modes in the single-motor driving mode, and second function relationship linear curves corresponding to various second sub-modes in the multi-motor driving mode;

[0016] The target vehicle speed is taken as a first search target, and the preset curve database is traversed to determine an initial function relationship linear curve, so as to form an initial function relationship linear curve library;

[0017] The target torque is taken as a second search target, and the initial function relationship linear curve library is traversed to determine the function relationship linear curve.

[0018] Further, the step of constructing the preset curve database comprises:

[0019] obtaining a historical characteristic parameter database, the historical characteristic parameter database comprising a plurality of first historical vehicle speeds of the target vehicle in the single-machine driving mode and first historical torques corresponding to each of the first historical vehicle speeds, the first historical torque being a torque of the first motor or the second motor, and the historical characteristic parameter database further comprising a plurality of second historical vehicle speeds of the target vehicle in the multi-machine driving mode and second historical torques corresponding to each of the second historical vehicle speeds, the second historical torque being a sum of the torques of the first motor and the second motor;

[0020] obtaining a plurality of first function relationship linear curves corresponding to each of the first sub-modes in the single-machine driving mode according to the plurality of first historical vehicle speeds and the first historical torques corresponding to each of the first historical vehicle speeds;

[0021] obtaining a plurality of second function relationship linear curves corresponding to each of the second sub-modes in the multi-machine driving mode according to the plurality of second historical vehicle speeds and the second historical torques corresponding to each of the second historical vehicle speeds.

[0022] Further, the step of obtaining a plurality of first function relationship linear curves corresponding to each of the first sub-modes in the single-machine driving mode according to the plurality of first historical vehicle speeds and the first historical torques corresponding to each of the first historical vehicle speeds comprises:

[0023] constructing a first rectangular coordinate system with the first historical vehicle speeds as the X-axis and the first historical torques as the Y-axis;

[0024] forming a plurality of first coordinate points in the first rectangular coordinate system according to the plurality of first historical vehicle speeds and the first historical torques corresponding to each of the first historical vehicle speeds;

[0025] marking, as a first group of coordinate points, the first coordinate points in which the first historical torques are greater than or equal to the first set torque and less than or equal to the second set torque, and marking, as a second group of coordinate points, the first coordinate points in which the first historical torques are less than the first set torque;

[0026] connecting all the coordinate points in the first group of coordinate points in sequence along the X-axis direction to obtain a first function relationship linear curve corresponding to the transmission driven by the first motor or the second motor in the first gear position in the single-machine driving mode, and marking the first function relationship linear curve as a first single-machine function relationship linear curve;

[0027] Connecting all the coordinate points in the third group of coordinate points in sequence along the direction of the X axis, a second function relationship linear curve corresponding to the first motor being in the second gear and the second motor being in the second gear in the multi-machine driving mode is obtained, and the second function relationship linear curve is marked as a first multi-machine function relationship linear curve.

[0028] Further, the step of obtaining the second function relationship linear curve corresponding to each second sub-mode in the multi-machine driving mode respectively according to the plurality of second historical vehicle speeds and the second historical torque corresponding to each second historical vehicle speed comprises:

[0029] A second rectangular coordinate system is constructed with the second historical vehicle speed as the X axis and the second historical torque as the Y axis.

[0030] A plurality of second coordinate points are formed in the second rectangular coordinate system according to the plurality of second historical vehicle speeds and the second historical torque corresponding to each second historical vehicle speed.

[0031] The second coordinate points in the plurality of second coordinate points whose second historical torque is less than the third set torque are marked as a third group of coordinate points, the second coordinate points whose second historical torque is greater than or equal to the third set torque and less than or equal to the fourth set torque are marked as a fourth group of coordinate points, and the second coordinate points whose second historical torque is greater than the fourth set torque and less than or equal to the fifth set torque are marked as a fifth group of coordinate points.

[0032] Connecting all the coordinate points in the third group of coordinate points in sequence along the direction of the X axis, a second function relationship linear curve corresponding to the first motor being in the second gear and the second motor being in the second gear in the multi-machine driving mode is obtained, and the second function relationship linear curve is marked as a first multi-machine function relationship linear curve.

[0033] Connecting all the coordinate points in the fourth group of coordinate points in sequence along the direction of the X axis, a second function relationship linear curve corresponding to the first motor being in the first gear and the second motor being in the second gear in the multi-machine driving mode is obtained, and the second function relationship linear curve is marked as a second multi-machine function relationship linear curve.

[0034] Connecting all the coordinate points in the fifth group of coordinate points in sequence along the direction of the X axis, a second function relationship linear curve corresponding to the first motor being in the first gear and the second motor being in the first gear in the multi-machine driving mode is obtained, and the second function relationship linear curve is marked as a third multi-machine function relationship linear curve.

[0035] Further, the step of obtaining the target driving mode corresponding to the target vehicle speed and the target torque and marking the target driving mode to obtain a target driving mode comprises:

[0036] If the coordinate point of the target vehicle speed and the target torque in the first rectangular coordinate system is only in the region surrounded by the first single-machine function linear curve and the second single-machine function linear curve, the driving mode corresponding to the first single-machine function linear curve is taken as the target driving mode.

[0037] Further, the preset curve database includes the first single-machine function linear curve, the second single-machine function linear curve, the third multi-machine function linear curve and the second multi-machine function linear curve, the driving mode corresponding to the target vehicle speed and the target torque is obtained and marked, and the target driving mode is obtained.

[0038] When the target vehicle speed and the target torque are in the region surrounded by the first single-machine function linear curve and the second single-machine function linear curve, and at the same time, the target vehicle speed and the target torque are in the region surrounded by the third multi-machine function linear curve and the second multi-machine function linear curve, the vehicle operating parameters are obtained, and the vehicle operating parameters at least include the real-time vehicle speed and the rotation speed of the first motor and the second motor.

[0039] The first energy consumption corresponding to the first single-machine function linear curve and the second energy consumption corresponding to the third multi-machine function linear curve are calculated according to the vehicle operating parameters, the target vehicle speed and the target torque.

[0040] The driving mode corresponding to the minimum value of the first energy consumption and the second energy consumption is taken as the target driving mode.

[0041] Further, the first historical vehicle speed is taken as the X axis, and the first historical torque is taken as the Y axis to construct the first rectangular coordinate system, the second historical vehicle speed is taken as the X axis, and the second historical torque is taken as the Y axis to construct the second rectangular coordinate system, the driving mode corresponding to the target vehicle speed and the target torque is obtained and marked, and the target driving mode is obtained.

[0042] When the coordinate point of the target vehicle speed and the target torque in the first rectangular coordinate system is in the region surrounded by the second single-machine function linear curve and the X axis of the first rectangular coordinate system, and at the same time, the coordinate point of the target vehicle speed and the target torque in the second rectangular coordinate system is in the region surrounded by the second multi-machine function linear curve and the X axis of the second rectangular coordinate system, the vehicle operating parameters are obtained, and the vehicle operating parameters at least include the real-time vehicle speed and the rotation speed of the first motor and the second motor.

[0043] The third energy consumption corresponding to the second single-machine function linear curve, the fourth energy consumption corresponding to the second multi-machine function linear curve and the fifth energy consumption corresponding to the first multi-machine function linear curve are calculated according to the vehicle operating parameters, the target vehicle speed and the target torque.

[0044] The driving mode corresponding to the minimum value among the third energy consumption, the fourth energy consumption and the fifth energy consumption is taken as the target driving mode.

[0045] Further, after the step of taking the driving mode corresponding to the minimum value among the first energy consumption and the second energy consumption as the target driving mode, the method further comprises:

[0046] When the second energy consumption is smaller than the first energy consumption, the maximum torque of the first motor is obtained;

[0047] The maximum torque is divided into a plurality of first sub-torques by a set torque interval;

[0048] The first energy consumption of the first motor corresponding to each first sub-torque is calculated while the rotating speed of the first motor is kept unchanged;

[0049] The torque corresponding to the minimum value among the plurality of first energy consumptions is determined as the current torque of the first motor;

[0050] The current torque of the second motor is determined according to the target torque and the current torque of the first motor;

[0051] The first torque request is sent to the controller of the first motor so that the first motor responds and operates at the current torque of the first motor, and the second torque request is sent to the controller of the second motor so that the second motor responds and operates at the current torque of the second motor.

[0052] Further, the step of determining the current torque of the second motor according to the target torque and the current torque of the first motor comprises:

[0053] The torque difference between the target torque and the current torque of the first motor is calculated;

[0054] The second energy consumption of the second motor corresponding to all the first sub-torques smaller than the torque difference among the plurality of first sub-torques is calculated while the rotating speed of the second motor is kept unchanged;

[0055] The torque corresponding to the minimum value among the plurality of second energy consumptions is determined as the current torque of the second motor.

[0056] By the preset curve database, the function relationship linear curve matched with the current target vehicle speed and target torque can be quickly and accurately found, and the optimal driving mode (single motor or double motors) is determined.

[0057] In the multi-motor driving mode, the torques of the first motor and the second motor can be reasonably allocated according to the target torque and the motor characteristics, so that they operate in the highest efficiency interval while meeting the power demand of the vehicle, further reducing the energy consumption and improving the economy of the system.

[0058] By utilizing the connection characteristics of the shift mechanism and the planetary gear, the driving method of the application can realize smooth and efficient shifting operation, avoid power interruption, and improve the driving experience. In particular, by controlling the operating efficiency of the motor to switch to the target total efficiency, it is ensured that the motor can work in the optimal state under any driving mode, thereby enhancing the power performance of the system.

[0059] The driving method of the application can monitor the driving state of the target vehicle in real time, such as vehicle speed and load. Once the vehicle operating condition changes are monitored, such as the sum of the target vehicle speed and the real-time speed equaling the target total speed, the motor operating state can be immediately adjusted to achieve the target total efficiency, thereby enhancing the flexibility and adaptability of the system.

[0060] By comprehensively considering the motor efficiency, transmission efficiency and energy consumption, the driving method of the application can realize the overall energy efficiency optimization of the dual-motor electric drive axle system, not only reducing energy consumption, but also improving power performance, achieving the dual improvement of economy and power performance, and providing strong support for the efficient operation of electric vehicles.

[0061] Since the sliding sleeve type shift mechanism with simple structure is adopted, the driving method of the application can reduce the design and manufacturing cost of the shift mechanism while ensuring efficient shifting, thereby increasing the economic competitiveness of the system.

[0062] The driving method of the application ensures that there is no power interruption during the shifting process by dynamically adjusting the motor operating efficiency, thereby providing a smoother driving experience and improving the comfort of the vehicle.

[0063] In summary, the dual-motor electric drive axle driving method of the application not only effectively solves the deficiencies of the existing electric drive system in energy consumption, power performance and shifting smoothness, but also realizes the precise matching of the vehicle operating condition through intelligent control strategy, thereby improving the overall system operating efficiency and driving experience. BRIEF DESCRIPTION OF DRAWINGS

[0064] The drawings accompanying the specification of this application form a part thereof, serve to provide further understanding of the application, and together with the description of the exemplary embodiments of the application and the explanation thereof serve to explain the application, and do not constitute improper limitations on the application. In the drawings:

[0065] Figure 1 The driving architecture of the dual-motor electric drive axle of the embodiment of the application is shown;

[0066] Figure 2 The driving method of the dual-motor electric drive axle of the embodiment of the application is shown.

[0067] Among them, the above drawings include the following reference signs:

[0068] 1, first wheel edge speed reducer; 1601, gear ring; 1602, planetary gear; 1603, sun gear; 2, first shift sleeve; 3, first shift motor; 4, first motor; 5, differential; 6, second motor; 15, first output shaft; 17, another planetary gear; 18, shift mechanism; 19, second output shaft. DETAILED DESCRIPTION

[0069] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0070] The present application provides a driving method for a dual-motor electric drive axle, which is applicable to an electric drive axle architecture comprising a first motor 4 and a second motor 6 arranged symmetrically, and a planetary gear set, wherein the output shaft of the first motor 4 is connected to a sun gear 1603 in the planetary gear set, and the sun gear 1603 is selectively connected to a planetary gear 1602 or a gear ring 1601 in the planetary gear set to complete gear shifting under the action of a shift mechanism, such as Figure 2 The driving method comprises the following steps:

[0071] S1, obtaining a target vehicle speed and a target torque of a target vehicle within a predetermined distance during operation of the target vehicle, wherein the target torque is the sum of the torques of the first motor and the second motor.

[0072] The present embodiment provides a driving method for a dual-motor electric drive axle, which is particularly designed for an electric drive axle system with a specific architecture comprising a first motor 4 and a second motor 6 arranged symmetrically, and a planetary gear set, wherein the output shaft of the first motor is directly connected to a sun gear in the planetary gear set, and the sun gear is indirectly connected to a planetary carrier or a gear ring through a planetary gear to realize gear shifting.

[0073] The driving method is applicable to an electric drive axle architecture comprising a first motor 4 and a second motor 6 and a planetary gear set, wherein the output shaft of the first motor 4 is connected to a sun gear in the planetary gear set, and the sun gear is selectively connected to a planetary gear or a gear ring in the planetary gear set to complete gear shifting under the action of a shift mechanism 18, which comprises a first shift motor 3 and a first shift sleeve 2 driven by the first shift motor 3, wherein the first shift motor 3 drives the first shift sleeve 2 to move left and right in Figure 1 , and the positions of the first shift sleeve 2 from left to right are A, B and C, wherein when in AB, it is the first gear position, and when in AC, it is the second gear position.

[0074] In use, when the first shift sleeve 2 is in the first shift position, the first motor 4 outputs power to the first output shaft 15, the first output shaft 15 transmits power to the sun gear 1603, the sun gear 1603 transmits power to the planetary gear 1602, the planetary gear 1602 transmits power to the planet carrier, the planet carrier transmits power to the first shift sleeve 2, and the power is transmitted to the differential 5 through the first shift sleeve 2, and then transmitted to the second output shaft 19 by the differential 5, and then transmitted to the first rim reducer 1 by the second output shaft 19, and then transmitted to the hub on the left side, driving the left tire to rotate; similarly, the right side structure is symmetrical to the left side, and the power transmission process is consistent.

[0075] In use, when the first shift sleeve 2 is in the second shift position, the first motor 4 transmits power to the first output shaft 15, the first output shaft 15 transmits power to the sun gear 1603, the sun gear 1603 transmits power to the ring gear 1601, the ring gear 1601 transmits power to the planetary gear of the other planetary gear set 17, and the planet carrier of the other planetary gear set 17 transmits power to the planet carrier of the other planetary gear set 17, and the planet carrier of the other planetary gear set 17 transmits power to the first shift sleeve 2, and the power is transmitted to the differential 5 through the first shift sleeve 2, and then transmitted to the second output shaft 19 by the differential 5, and then transmitted to the first rim reducer 1 by the second output shaft 19, and then transmitted to the hub on the left side, driving the left tire to rotate; similarly, the right side structure is symmetrical to the left side, and the power transmission process is consistent. The above process is the process when the first shift sleeve 2 is in the first shift position and the second shift position.

[0076] The implementation steps of the driving method are described in detail as follows:

[0077] Obtain target vehicle speed and target torque:

[0078] In the predetermined journey of the target vehicle, the vehicle operating state is monitored in real time, and the data of the target vehicle speed (i.e. the current or expected driving speed of the vehicle) and the target torque (the total torque output by the first motor and the second motor) are collected. These data can be obtained by vehicle-mounted sensors such as speed sensors, torque sensors, etc., or can be calculated by the input of the driver (such as the position of the accelerator pedal, the selection of the driving mode, etc.).

[0079] By monitoring the target speed and target torque of the target vehicle, the dual-motor multi-speed electric drive axle architecture of the present invention can quickly calculate and determine the most economical drive mode. It can not only intelligently select single-motor or dual-motor drive, but also, in the dual-motor drive mode, perform optimal torque distribution according to the target torque (i.e., the sum of the torques of the first motor and the second motor), ensuring that each motor operates at its most efficient operating point, thereby reducing power consumption and improving energy utilization efficiency.

[0080] Under different working conditions, the electric drive axle of the present invention can achieve mode switching without power interruption, ensuring driving smoothness while avoiding power loss in the traditional gear shifting process. This smooth switching capability is crucial to improving the driving experience and overall vehicle performance.

[0081] This invention utilizes an economical shifting schedule, enabling the motor to operate in the most appropriate gear according to vehicle speed, thereby meeting power requirements while minimizing energy consumption. This feature is particularly prominent at high speeds, effectively avoiding wasted motor power and reducing overall vehicle energy consumption.

[0082] Taking into account the various operating conditions that the target vehicle may encounter during its scheduled journey, the drive strategy design of the present invention fully considers the operating conditions, scenarios, minimum energy consumption, motor efficiency MAP and optimal torque distribution of the dual motors, so that the electric drive axle system can flexibly adapt to various driving conditions and maintain excellent performance whether it is urban congestion, high-speed cruising or complex road conditions.

[0083] By simplifying the shift mechanism design, the present invention reduces the use of complex planetary gear mechanisms, lowering the overall cost of the system. The dual-motor configuration can further reduce costs through economies of scale, while also reducing power consumption by operating the motors in their high-efficiency range.

[0084] Because the present invention reduces vehicle energy consumption and electricity consumption, it indirectly reduces carbon emissions during electricity production, making a positive contribution to environmental protection. Furthermore, operating the motor in its high-efficiency range reduces noise and heat emissions, further enhancing the vehicle's environmental performance.

[0085] S2. Searching a preset curve database for a linear curve that satisfies the functional relationship between the target vehicle speed and the target torque;

[0086] Specifically, a preset curve database is constructed, the preset curve database including first functional relationship linear curves corresponding to various first sub-modes in the single-machine driving mode, and second functional relationship linear curves corresponding to various second sub-modes in the multi-machine driving mode;

[0087] The steps of constructing a preset curve database include:

[0088] The historical characteristic parameter database includes a plurality of first historical vehicle speeds of the target vehicle in the single-machine driving mode and first historical torques corresponding to each first historical vehicle speed, the first historical torque being a torque of the first motor or the second motor. The historical characteristic parameter database further includes a plurality of second historical vehicle speeds of the target vehicle in the multi-machine driving mode and second historical torques corresponding to each second historical vehicle speed, the second historical torque being a sum of the torques of the first motor and the second motor.

[0089] In order to construct a preset curve database capable of effectively guiding the intelligent operation of the dual-motor electric drive axle system, the following steps detail how to extract data from the historical characteristic parameter database, analyze and establish the linear function relationship curve under various driving modes, and provide decision basis for driving mode selection and motor torque distribution under dynamic working conditions.

[0090] Firstly, historical data of the target vehicle running in different driving environments and working conditions are collected, including vehicle speed, motor torque and other key parameters under single-machine driving mode and multi-machine driving mode. These data can be obtained through vehicle event data recorder, vehicle-mounted sensors or driver's operation records, etc.

[0091] The collected historical data are cleaned and arranged to ensure the accuracy and integrity of the data. The data are classified according to driving modes and stored as historical characteristic parameters of the target vehicle in single-machine driving mode and multi-machine driving mode, respectively, to construct the historical characteristic parameter database.

[0092] Single-machine driving mode curve construction: taking the first historical vehicle speed as the X-axis and the corresponding first historical torque (i.e. the torque of the first motor or the second motor) as the Y-axis, a first rectangular coordinate system is constructed. In this coordinate system, all the combination points of the collected first historical vehicle speed and first historical torque are plotted as coordinate points.

[0093] According to the corresponding relationship between the first historical vehicle speed and the first historical torque, a curve is fitted. Each first sub-mode (i.e. different gears under single-machine driving mode) will generate a first linear function relationship curve, representing the relationship between motor torque and vehicle speed under this mode.

[0094] Multi-machine driving mode curve construction: taking the second historical vehicle speed as the X-axis and the corresponding second historical torque (i.e. the sum of the torques of the first motor and the second motor) as the Y-axis, a second rectangular coordinate system is constructed, and all the combination points of the collected second historical vehicle speed and second historical torque are plotted as coordinate points.

[0095] According to the corresponding relationship between the second historical vehicle speed and the second historical torque, a second function relationship linear curve of each second sub-mode (i.e. different gear combinations in the multi-machine driving mode) is generated, ensuring that all possible multi-machine driving modes are covered.

[0096] The preset curve database is established: the preset curve database is designed and established, and all the first function relationship linear curves and the second function relationship linear curves constructed above are stored in different driving modes and sub-modes.

[0097] In order to ensure the accuracy and timeliness of the database, a curve updating mechanism is designed. The curves in the database are updated regularly or according to specific conditions (such as vehicle maintenance, software upgrade, etc.) to reflect the latest changes and optimization improvements of vehicle performance.

[0098] During the operation of the target vehicle, the system obtains the target vehicle speed and target torque in real time, and compares them with the curves in the preset curve database to determine the optimal driving mode and motor torque distribution strategy.

[0099] The preset curve database is an important decision basis for the intelligent driving system, which can guide the system to quickly and accurately select the most economical and effective driving mode according to the current working condition, and realize smooth gear shifting and torque distribution of the motor in the high-efficiency gear.

[0100] The preset curve database contains the function relationship linear curves of various first sub-modes in single-machine driving mode and various second sub-modes in multi-machine driving mode. These curves are based on the data in the historical characteristic parameter database, including the running state of the target vehicle at different speeds and torques. Through database query, the invention can quickly and accurately find the driving mode that meets the current target vehicle speed and target torque, and realize the best motor operating state.

[0101] According to the target vehicle speed and target torque, the invention can find the motor operating point with the lowest energy consumption from the preset curve database. This intelligent matching mechanism ensures that the motor can operate in the high-efficiency area under any working condition, reduces the overall energy consumption, and improves the energy utilization rate. It has a significant improvement on the endurance and economy of electric vehicles.

[0102] The linear function relationship curves in the preset curve database not only provide the optimal operating point of the motor in different driving modes, but also guide the smooth transition of the electric drive axle between various modes, avoiding the power interruption or impact that may occur during mode switching, and improving the comfort and safety of driving.

[0103] The establishment of the historical characteristic parameter database enables the electric drive axle system of the application to make decisions based on a large amount of historical data. This data-driven intelligent analysis improves the accuracy and reliability of system decision-making, better responds to future unknown working condition changes, and improves the adaptability and flexibility of the vehicle.

[0104] By optimizing the motor operating state and shifting strategy, the application reduces unnecessary power consumption, thereby reducing the operating cost of the vehicle. At the same time, due to the reduction of energy waste, the application also helps to reduce carbon emissions and other environmental impacts, in line with global environmental protection trends, with significant social and environmental benefits.

[0105] The use of the preset curve database enables the electric drive axle system to adjust the driving mode and motor operating state in real time during vehicle operation, ensuring that the vehicle performance is always in the best state, whether in urban low-speed driving or on the highway, providing the best driving experience and performance.

[0106] According to the plurality of first historical vehicle speeds and the first historical torque corresponding to each first historical vehicle speed, a first function relationship linear curve corresponding to each first sub-mode in the single-machine driving mode is obtained.

[0107] Specifically, a first rectangular coordinate system is constructed with the first historical vehicle speed as the X-axis and the first historical torque as the Y-axis.

[0108] According to the plurality of first historical vehicle speeds and the first historical torque corresponding to each first historical vehicle speed, a plurality of first coordinate points are formed in the first rectangular coordinate system.

[0109] The first coordinate points in the plurality of first coordinate points in which the first historical torque is greater than or equal to the first set torque and less than or equal to the second set torque are marked as the first group of coordinate points, and the first coordinate points in the plurality of first coordinate points in which the first historical torque is less than the first set torque are marked as the second group of coordinate points.

[0110] In the X-axis direction, all coordinate points in the first group of coordinate points are sequentially connected to obtain a first function relationship linear curve corresponding to the first motor or the second motor driving connection of the transmission in the first gear position in the single-machine driving mode, which is marked as the first single-machine function relationship linear curve.

[0111] In the X-axis direction, all coordinate points in the second group of coordinate points are sequentially connected to obtain a first function relationship linear curve corresponding to the first motor or the second motor driving connection of the transmission in the second gear position in the single-machine driving mode, which is marked as the second single-machine function relationship linear curve.

[0112] This embodiment focuses on constructing the function relationship linear curve of the first motor or the second motor in single motor driving mode, which will be used to guide the driving strategy optimization and motor gear selection, ensuring that the motor can operate at optimal efficiency under different working conditions. The following are the detailed steps:

[0113] Collect the historical data of the target vehicle in actual operation, including the first historical vehicle speed and the first historical torque in single motor driving mode, which refers to the output torque of any motor (first motor or second motor).

[0114] Preprocess the collected first historical vehicle speed and first historical torque data, including data cleaning and format standardization, to ensure the accuracy and consistency of the data.

[0115] Define a first rectangular coordinate system with the first historical vehicle speed as the X-axis and the first historical torque as the Y-axis. Each combination of first historical vehicle speed and first historical torque in the historical data is plotted as a coordinate point according to the defined coordinate system.

[0116] According to the size of the torque, the first coordinate point is divided into two groups. The coordinate points with torque between the first set torque and the second set torque are the first group of coordinate points, marked as "torque working interval A"; the coordinate points with torque less than the first set torque are the second group of coordinate points, marked as "torque working interval B".

[0117] In the first rectangular coordinate system, connect the first group of coordinate points in sequence along the X-axis direction to form a continuous curve, which represents the linear relationship between the torque and the vehicle speed of the motor in the first gear, marked as "first single motor function relationship linear curve".

[0118] Similarly, in the first rectangular coordinate system, connect the second group of coordinate points in sequence along the X-axis direction to form a continuous curve, which represents the linear relationship between the torque and the vehicle speed of the motor in the second gear, marked as "second single motor function relationship linear curve".

[0119] The established function relationship linear curve will be used to guide the gear selection and torque distribution of the motor in single motor driving mode. When the monitored target vehicle speed and target torque are located in "torque working interval A", the system will refer to "first single motor function relationship linear curve" for gear and torque adjustment, ensuring that the motor operates in the first gear; when located in "torque working interval B", it will refer to "second single motor function relationship linear curve" to adjust the motor to operate in the second gear.

[0120] The system will monitor the vehicle speed and torque demand in real time, compare it with the pre-built function relationship linear curve, and determine whether to select single motor drive mode, which motor (first motor or second motor) and which gear (first gear or second gear) to drive under the current working condition to achieve the best energy efficiency ratio and driving experience.

[0121] By constructing the first function relationship linear curve of the first motor or the second motor in single motor drive mode, the system can quickly determine the optimal torque that matches the target vehicle speed. This mechanism ensures that the transmission driven by the first motor or the second motor can run efficiently in the first gear and the second gear, avoiding energy waste caused by mismatch between torque and vehicle speed.

[0122] The pre-set first single motor function relationship linear curve and the second single motor function relationship linear curve provide the basis for intelligent gear shifting for the electric drive axle system. When the target torque is between the first set torque and the second set torque, the first gear corresponding to the first single motor function relationship linear curve will be automatically selected. If the target torque is lower than the first set torque, the system switches to the second gear corresponding to the second single motor function relationship linear curve, realizing a more economical operation mode.

[0123] During vehicle driving, the current vehicle speed and torque demand can be monitored in real time, and adjustments can be made quickly by querying the pre-set function relationship linear curve. This real-time performance optimization capability ensures that the motor always operates in the best state, providing stable and efficient power output whether driving at low speed or cruising at high speed, improving the driving experience.

[0124] By marking the first group and the second group of coordinate points and constructing the corresponding function relationship linear curves, the invention can accurately identify and adapt to various working conditions. This working condition adaptability based on historical data enables the system to make more accurate decisions when facing complex and variable driving environments, enhancing the stability and reliability of the system.

[0125] The method of constructing function relationship linear curves simplifies the control logic and avoids complex real-time calculations. By monitoring the vehicle speed and torque, the system can find the optimal operating state according to the pre-set curve, reducing control complexity and improving the response speed and control accuracy of the system.

[0126] By improving the operating efficiency of the motor and reducing unnecessary gear shifting, the invention helps to reduce operating costs and energy consumption, thereby reducing carbon emissions and having a positive impact on environmental protection. In addition, the optimized motor operating state also reduces noise and vibration, improving driving comfort.

[0127] According to the plurality of second historical vehicle speeds and the second historical torque corresponding to each second historical vehicle speed, a second function relationship linear curve corresponding to each second sub-mode in the multi-machine driving mode is obtained;

[0128] Specifically, a second rectangular coordinate system is constructed with the second historical vehicle speed as the X-axis and the second historical torque as the Y-axis.

[0129] According to the plurality of second historical vehicle speeds and the second historical torque corresponding to each second historical vehicle speed, a plurality of second coordinate points are formed in the second rectangular coordinate system.

[0130] The second coordinate points in the plurality of second coordinate points whose second historical torque is less than the third set torque are marked as a third group of coordinate points, the second coordinate points whose second historical torque is greater than or equal to the third set torque and less than or equal to the fourth set torque are marked as a fourth group of coordinate points, and the second coordinate points whose second historical torque is greater than the fourth set torque and less than or equal to the fifth set torque are marked as a fifth group of coordinate points.

[0131] Along the X-axis direction, all coordinate points in the third group of coordinate points are sequentially connected to obtain a second function relationship linear curve corresponding to the case that the transmission driven by the first motor is in the second gear and the transmission driven by the second motor is in the second gear in the multi-machine driving mode, which is marked as a first multi-machine function relationship linear curve.

[0132] Along the X-axis direction, all coordinate points in the fourth group of coordinate points are sequentially connected to obtain a second function relationship linear curve corresponding to the case that the transmission driven by the first motor is in the first gear and the transmission driven by the second motor is in the second gear in the multi-machine driving mode, which is marked as a second multi-machine function relationship linear curve.

[0133] Along the X-axis direction, all coordinate points in the fifth group of coordinate points are sequentially connected to obtain a second function relationship linear curve corresponding to the case that the transmission driven by the first motor is in the first gear and the transmission driven by the second motor is in the first gear in the multi-machine driving mode, which is marked as a third multi-machine function relationship linear curve.

[0134] Taking the target vehicle speed as a first search target, the preset curve database is traversed to determine an initial function relationship linear curve, thereby forming an initial function relationship linear curve library.

[0135] Taking the target torque as a second search target, the initial function relationship linear curve library is traversed to determine the function relationship linear curve.

[0136] The second historical vehicle speed and the second historical torque data of the target vehicle running in the multi-machine driving mode are extracted from the historical characteristic parameter database, and these data represent the vehicle performance under the joint action of the dual motors.

[0137] Define a second rectangular coordinate system, in which the second historical vehicle speed is the X-axis and the second historical torque is the Y-axis. Plot all the second historical vehicle speed and second historical torque combination data points as second coordinate points, which are distributed in the second rectangular coordinate system.

[0138] Torque interval division: According to the size of the torque, the second coordinate points are divided into three groups. The coordinate points with torque less than the third set torque are marked as the third group of coordinate points. The coordinate points with torque between the third set torque and the fourth set torque are marked as the fourth group of coordinate points. The coordinate points with torque greater than the fourth set torque and not exceeding the fifth set torque are marked as the fifth group of coordinate points. The five set torque values are pre-set according to the performance of the motor and the running characteristics of the vehicle.

[0139] First multi-machine function relationship linear curve: along the X-axis direction, all coordinate points in the third group of coordinate points are connected in sequence using linear interpolation or curve fitting method to form a curve, which represents the multi-machine drive mode characteristics when the first motor drive connected transmission is in second gear and the second motor drive connected transmission is also in second gear, marked as "first multi-machine function relationship linear curve".

[0140] Second multi-machine function relationship linear curve: similarly, along the X-axis direction, all coordinate points in the fourth group of coordinate points are connected to form a curve representing the multi-machine drive mode characteristics when the first motor drive connected transmission is in first gear and the second motor drive connected transmission is in second gear, marked as "second multi-machine function relationship linear curve".

[0141] Third multi-machine function relationship linear curve: finally, along the X-axis direction, all coordinate points in the fifth group of coordinate points are connected to obtain a curve representing the multi-machine drive mode characteristics when the first motor drive connected transmission is in first gear and the second motor drive connected transmission is also in first gear, marked as "third multi-machine function relationship linear curve".

[0142] Store the constructed "first multi-machine", "second multi-machine" and "third multi-machine" function relationship linear curves in the preset curve database to form an initial function relationship linear curve library.

[0143] Take the target vehicle speed as the search target, traverse the preset curve database, and find the initial function relationship linear curve corresponding to the target vehicle speed to preliminarily determine the possible drive mode.

[0144] Take the target torque as the search target, further traverse the preliminarily determined initial function relationship linear curve library, and determine the function relationship linear curve that best meets the target torque demand through comparison between the curves, thereby determining the optimal multi-machine drive mode.

[0145] Curve application: By searching for a curve that matches the target speed and target torque in the preset curve database, the system can intelligently select the most economical driving mode, which includes determining the gear and torque distribution strategy of the motor to ensure that the motor operates in the high-efficiency zone while meeting the power demand of the vehicle.

[0146] By constructing a second function relationship linear curve based on historical data, the load of the two motors can be intelligently distributed according to different vehicle speeds and torque demands. The first, second, and third multi-machine function relationship linear curves correspond to three different gear combinations, ensuring that the most economical and efficient motor torque distribution scheme can be found under any working condition.

[0147] The system adjusts the initial function relationship linear curve in real time according to the target speed and target torque, and this dynamic working condition matching capability enables the dual-motor system to quickly adapt to different driving conditions such as urban congestion, high-speed driving, or climbing conditions, providing continuous, stable, and efficient power output.

[0148] The function relationship linear curve constructed based on historical vehicle speed and torque data can guide the system to select the mode and motor operating point with the lowest energy consumption while meeting the vehicle performance requirements, achieving an effective balance between performance and economy, which is of great significance for improving the vehicle's endurance and reducing power consumption.

[0149] By constructing a linear curve database, the complexity of real-time decision-making is simplified. Compared to real-time calculation of optimal motor torque and gear combination, the system only needs to find the corresponding linear curve according to the target speed and torque, greatly reducing the calculation time and resource consumption, and improving the response speed and efficiency of the control system.

[0150] Through fine motor torque distribution and gear selection, the invention can reduce the fluctuation of power output and improve driving smoothness, while the intelligent working condition adaptation capability can also reduce the impact during gear shifting and improve overall driving comfort.

[0151] Considering the motor torque distribution strategy with the lowest energy consumption not only helps to reduce power consumption and operating costs, but also reduces carbon emissions, which has a positive impact on environmental protection. In addition, by optimizing the motor operating state, unnecessary maintenance and wear are reduced, further improving cost efficiency.

[0152] The invention makes full use of historical data for decision-making, embodying the concept of data-driven intelligent control. This big data-based decision-making mode not only improves the accuracy and reliability of decision-making, but also demonstrates the potential of technology in future development, enabling continuous learning and optimization to adapt to more complex and variable driving environments.

[0153] S3. Obtaining a driving mode corresponding to both the target vehicle speed and the target torque based on the correspondence between the linear curve of the functional relationship and the driving mode, marking the driving mode, and obtaining a target driving mode;

[0154] Specifically, if the coordinate points of the target vehicle speed and the target torque in the first rectangular coordinate system are only within the area enclosed by the first single-machine function relationship linear curve and the second single-machine function relationship linear curve, the driving mode corresponding to the first single-machine function relationship linear curve is used as the target driving mode;

[0155] When it is determined that the target vehicle speed and the target torque are within a region enclosed by the first single-machine function relationship linear curve and the second single-machine function relationship linear curve, and when it is determined that the target vehicle speed and the target torque are within a region enclosed by the third multi-machine function relationship linear curve and the second multi-machine function relationship linear curve, obtaining vehicle operating parameters, the vehicle operating parameters including at least the real-time vehicle speed and the rotational speeds of the first motor and the second motor;

[0156] Calculating a first energy consumption corresponding to a first linear curve of a single-machine function relationship and a second energy consumption corresponding to a third linear curve of a multi-machine function relationship according to vehicle operating parameters, target vehicle speed, and target torque;

[0157] taking a driving mode corresponding to a minimum value between the first energy consumption and the second energy consumption as a target driving mode;

[0158] When it is determined that the second energy consumption is less than the first energy consumption, obtaining the maximum torque of the first motor;

[0159] dividing the maximum torque into a plurality of first partial torques at set torque intervals;

[0160] Controlling the rotation speed of the first motor to remain unchanged, and calculating the first power consumption of the first motor corresponding to each first component torque;

[0161] determining a torque corresponding to a minimum value among the plurality of first power consumptions as a current torque of the first motor;

[0162] Determining the current torque of the second motor according to the target torque and the current torque of the first motor; specifically, calculating the torque difference between the target torque and the current torque of the first motor;

[0163] controlling the rotation speed of the second motor to remain unchanged, and calculating the second power consumption of the second motor corresponding to all first partial torques that are smaller than the torque difference among the plurality of first partial torques;

[0164] determining a torque corresponding to a minimum value among the plurality of second power consumptions as a current torque of the second motor;

[0165] The calculation formula for the first energy consumption is as follows:

[0166]

[0167] E1 represents the first energy consumption;

[0168] T1 represents the real-time torque of the first motor during the operation of the target vehicle;

[0169] T2 represents the real-time torque of the second motor during the operation of the target vehicle;

[0170] n2 represents the real-time speed of the second motor;

[0171] n1 represents the real-time speed of the first motor;

[0172] η0 represents the transmission efficiency of the main reducer;

[0173] η1 represents the efficiency of the first motor;

[0174] η2 represents the efficiency of the second motor;

[0175] Δt represents the simulation duration;

[0176] The calculation formula of the real-time speed n2 of the second motor is as follows:

[0177]

[0178] The calculation formula of the real-time speed n1 of the first motor is as follows:

[0179]

[0180] u1=u2 represents the target vehicle speed, i0 represents the fixed speed ratio of the wheel-side reducer, i1 represents the speed ratio of the transmission driven by the first motor in the single-machine driving mode when it is in gear 1, and r represents the tire radius;

[0181] The calculation formula of the second energy consumption is as follows:

[0182]

[0183] E2 represents the second energy consumption;

[0184] T1 represents the real-time torque of the first motor during the operation of the target vehicle;

[0185] T2 represents the real-time torque of the second motor during the operation of the target vehicle;

[0186] n2 represents the real-time speed of the second motor;

[0187] n1 represents the real-time speed of the first motor;

[0188] η0 represents the transmission efficiency of the main reducer;

[0189] η1 represents the efficiency of the first motor;

[0190] η2 represents the efficiency of the second motor;

[0191] Δt represents the simulation duration;

[0192] The calculation formula of the real-time speed n2 of the second motor is as follows:

[0193]

[0194] The calculation formula of the real-time speed n1 of the first motor is as follows:

[0195]

[0196] In the formula, u1=u2 represents the target vehicle speed, i0 represents the fixed speed ratio of the wheel-side reducer, i1 represents the speed ratio of the transmission driven by the first motor in the single-machine driving mode when the transmission is in gear 2, and r represents the tire radius;

[0197] sending a first torque request to the controller of the first motor to make the first motor respond and run at the current torque of the first motor, and sending a second torque request to the controller of the second motor to make the second motor respond and run at the current torque of the second motor;

[0198] When the coordinate point of the target vehicle speed and the target torque in the first rectangular coordinate system is in the region surrounded by the second single-machine function linear curve and the X-axis of the first rectangular coordinate system, and at the same time, the coordinate point of the target vehicle speed and the target torque in the second coordinate system is in the region surrounded by the second multi-machine function linear curve and the X-axis of the second rectangular coordinate system, obtaining vehicle operating parameters, the vehicle operating parameters at least including the real-time vehicle speed and the speeds of the first motor and the second motor;

[0199] According to the vehicle operating parameters, the target vehicle speed and the target torque, respectively calculating a third energy consumption corresponding to the second single-machine function linear curve, a fourth energy consumption corresponding to the second multi-machine function linear curve, and a fifth energy consumption corresponding to the first multi-machine function linear curve;

[0200] The calculation formula of the third energy consumption is as follows:

[0201]

[0202] In the formula, E3 represents the third energy consumption;

[0203] T1 represents the real-time torque of the first motor in the target vehicle operating process;

[0204] n1 represents the real-time speed of the first motor;

[0205] η1 represents the efficiency of the first motor;

[0206] η2 represents the efficiency of the second motor;

[0207] Δt represents the simulation duration;

[0208] The calculation formula of the real-time speed n1 of the first motor is as follows:

[0209]

[0210] Where: u1=u2=u represents the target vehicle speed, i1 represents the speed ratio of the transmission connected to the first motor in the multi-motor drive mode when it is in first gear, and r represents the tire radius;

[0211] The calculation formula for the fourth energy consumption is:

[0212]

[0213] Where: E4 represents the fourth energy consumption;

[0214] T1 represents the real-time torque of the first motor during the operation of the target vehicle;

[0215] n1 represents the real-time speed of the first motor;

[0216] η1 represents the efficiency of the first motor;

[0217] η0 represents the transmission efficiency of the main reducer;

[0218] Δt represents the simulation duration;

[0219] The calculation formula of the real-time speed n1 of the first motor is as follows:

[0220]

[0221] Where: u1=u2=u represents the target vehicle speed, i2 represents the speed ratio of the first motor in the multi-motor drive mode when it is in second gear, and r represents the tire radius;

[0222] The calculation formula for the fifth energy consumption is:

[0223]

[0224] Where: E5 represents the fifth energy consumption;

[0225] T1 represents the real-time torque of the first motor during the operation of the target vehicle;

[0226] n1 represents the real-time speed of the first motor;

[0227] η2 represents the efficiency of the second motor;

[0228] η0 represents the transmission efficiency of the main reducer;

[0229] Δt represents the simulation duration;

[0230] The calculation formula of the real-time rotating speed n2 of the second motor is as follows:

[0231]

[0232] In the formula, u1=u2=u represents the target vehicle speed, i0 represents the fixed speed ratio of the wheel-side reducer, and r represents the tire radius;

[0233] The driving mode corresponding to the minimum value among the third energy consumption, the fourth energy consumption and the fifth energy consumption is taken as the target driving mode.

[0234] In the first rectangular coordinate system, the coordinate point position of the target vehicle speed and the target torque is determined, and it is judged whether the point is located in the area surrounded by the first single-machine function relationship linear curve and the second single-machine function relationship linear curve, which represents the applicable range of the single-machine driving mode.

[0235] If the target point is located in the single-machine driving mode area, the driving mode corresponding to the first single-machine function relationship linear curve is directly selected as the target driving mode.

[0236] If the target point is located in both the single-machine driving mode area and the multi-machine driving mode area (i.e. the area surrounded by the third multi-machine function relationship linear curve and the second multi-machine function relationship linear curve), the next energy consumption calculation is entered.

[0237] Based on the vehicle operating parameters (real-time vehicle speed, motor rotating speed, etc.) and the target vehicle speed and torque, the first energy consumption and the second energy consumption in the first single-machine mode and the third multi-machine mode are calculated respectively.

[0238] The first energy consumption and the second energy consumption are compared, and the driving mode with lower energy consumption is selected as the target driving mode. If the third multi-machine mode has lower energy consumption, the torque distribution step is entered.

[0239] The maximum torque of the first motor is obtained, and the torque interval is divided into a plurality of first sub-torques by setting the torque interval, the first electric consumption caused by each first sub-torque at a fixed rotating speed is calculated, and the first sub-torque with the minimum electric consumption is selected as the current torque of the first motor.

[0240] Based on the target torque and the current torque of the first motor, the torque difference between the two is calculated, and it is determined whether the difference can be met by the second motor at the current rotating speed. If yes, the electric consumption of the second motor that meets the torque difference is calculated, and the torque with the minimum electric consumption is selected as the current torque of the second motor.

[0241] The first torque request and the second torque request are sent to the controllers of the first motor and the second motor, so that the two motors run at the calculated current torques, and the execution of the driving strategy is ensured.

[0242] If the target point is located in both the second single-machine mode region and the second multi-machine mode region, and is also located in the first multi-machine mode region, repeat the above energy consumption calculation steps to compare the third energy consumption in the second single-machine mode, the fourth energy consumption in the second multi-machine mode, and the fifth energy consumption in the first multi-machine mode.

[0243] The driving mode with the lowest energy consumption is selected as the target driving mode, thereby maximizing energy efficiency while meeting power demand.

[0244] The present application can dynamically select the most economical and efficient driving mode between single-machine driving mode and multi-machine driving mode according to real-time monitoring of target vehicle speed and target torque. This dynamic matching capability ensures that the motor can operate in the best state under any working condition, improving the power performance and energy utilization efficiency of the vehicle.

[0245] By calculating the energy consumption (first to fifth energy consumption) under different driving modes, the driving mode with the lowest energy consumption can be selected as the target mode. This energy consumption optimization strategy not only reduces overall power consumption, but also improves the vehicle's endurance, which is particularly important for long-distance driving and frequent shifting conditions.

[0246] In multi-machine driving mode, the system can accurately calculate and distribute the torque of the first motor and the second motor, ensuring that the motor operates in the high-efficiency zone, and by minimizing the motor power consumption (first and second power consumption), the system realizes optimal torque distribution of the dual-motor, avoiding power waste and improving energy utilization.

[0247] Through intelligent selection of the target driving mode, the present application can ensure smooth transition between different driving modes, avoiding power interruption or impact during shifting, and improving driving smoothness and comfort.

[0248] The function relationship linear curve constructed by the system based on historical data can provide real-time and accurate decision-making basis. This data-driven decision-making mechanism not only improves the reliability of decision-making, but also demonstrates the adaptability and potential for future development of technology under complex working conditions.

[0249] The optimized driving mode and torque distribution strategy not only reduces energy consumption and carbon emissions, but also has a positive impact on environmental protection; at the same time, the operation of the motor in the high-efficiency zone also reduces maintenance costs and improves overall cost-effectiveness.

[0250] By intelligently selecting the driving mode and torque distribution, the present application can improve the overall power performance of the vehicle, including acceleration performance, climbing ability and cruising efficiency, so that the vehicle can maintain optimal performance under different driving conditions.

[0251] S4, determining the target total speed of the first motor and the second motor according to the target vehicle speed;

[0252] S5, when the real-time speed of the target vehicle is the target vehicle speed and the sum of the real-time speeds of the first motor and the second motor is the target total speed, controlling the running efficiency of the first motor and the second motor to switch to the target total efficiency, and driving the target vehicle to run in the target driving mode;

[0253] The driving mode includes a single-machine driving mode and a multi-machine driving mode. The single-machine driving mode is a mode of driving in any gear of the first motor or the second motor, and the multi-machine driving mode is a mode of driving in a combination of any gear of the first motor and any gear of the second motor.

[0254] According to the target vehicle speed and the transmission ratio (including the tire radius) of the vehicle, the target total speed of the first motor and the second motor is calculated. The total speed should ensure that the two motors have equal speeds when coupled, so as to achieve smooth power transmission.

[0255] The target total efficiency is a comprehensive efficiency value based on the target driving mode, considering factors such as motor efficiency, transmission efficiency, and energy consumption. Through the linear curve of the function relationship in the preset curve database, combined with the target vehicle speed and the target torque, the target total efficiency under the working condition can be calculated.

[0256] The running speed of the target vehicle is monitored in real time to determine whether the target vehicle speed is reached, and the real-time speed of the first motor and the second motor is monitored simultaneously to determine whether the sum of the real-time speeds of the two motors is equal to the target total speed.

[0257] When the real-time speed of the target vehicle is the set target vehicle speed, and the sum of the real-time speeds of the two motors is equal to the target total speed, it indicates that the vehicle is in an ideal working condition, and the running efficiency adjustment of the next stage can be entered.

[0258] According to the target driving mode, the running efficiency of the first motor and the second motor is controlled to switch to the target total efficiency. This may include adjusting the working state of the motor, the gear shifting logic, and the torque distribution strategy to ensure that the motor runs in the high efficiency area.

[0259] After adjusting the running efficiency of the two motors to the target total efficiency, the target vehicle is driven to run according to the target driving mode. If the target mode is single-machine driving, the selected motor (the first motor or the second motor) is controlled to run in the optimal gear; if the target mode is multi-machine driving, the two motors are controlled to cooperate and drive in the optimal gear combination.

[0260] In the real-time monitoring process, if the vehicle working condition changes, the current target vehicle speed and target torque will be re-evaluated, and the single-machine driving mode or the multi-machine driving mode will be intelligently selected according to the preset curve database.

[0261] Once the new target driving mode is determined, the operating states of the two motors, including gear selection and torque distribution, will be adjusted quickly to ensure that the vehicle operates at the target total speed and target total efficiency in the new mode.

[0262] The target total speed and efficiency of the first and second motors are predicted and determined based on the target vehicle speed, ensuring the motors operate at peak efficiency at specific speeds. This optimization significantly reduces energy consumption and improves energy efficiency, playing a significant role in extending the range of new energy vehicles.

[0263] When the target vehicle's real-time speed reaches the target speed and the sum of the current motors' real-time speeds matches the target total speed, the system intelligently switches the operating efficiency of the first and second motors to the target total efficiency. This instant adjustment capability enables the vehicle to quickly adapt to different operating conditions, improving driving flexibility and economy.

[0264] Whether in single-motor or multi-motor drive mode, the present invention intelligently selects the most appropriate drive mode based on real-time operating conditions. In single-motor drive mode, the system selects the most efficient motor for driving; in multi-motor drive mode, the system achieves more refined torque distribution through the combination of different gears, meeting the vehicle's power requirements in the most economical manner.

[0265] By switching intelligent driving modes and optimizing motor efficiency, the present invention minimizes energy consumption while ensuring vehicle power performance, thereby finding the best balance between power and economy.

[0266] The intelligent switching mechanism of the present invention can ensure the smoothness of the motor during gear shifting or mode switching, avoid power interruption or impact that may occur during traditional gear shifting, and enhance the driving experience.

[0267] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0268] The foregoing is considered as illustrative only of the principles of the application. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and practice described. Accordingly, all such variations are intended to be included within the scope of the present application as defined in the following claims, along with full equivalents thereof.

[0269] In the description of the present application, it is to be understood that the orientation or positional relationships indicated by terms such as "front", "back", "up", "down", "left", "right", "lateral", "vertical", "horizontal", "top", "bottom", and the like are generally based on the orientation or positional relationships shown in the drawings, and are merely intended to facilitate the description and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore cannot be construed as limiting the scope of protection of the present application. The orientation terms "inner", "outer" refer to the inner and outer relative to the contour of the components themselves.

[0270] For the convenience of description, spatial relative terms such as "over", "above", "upper surface", "upper", and the like can be used herein to describe the spatial positional relationship of one device or feature with respect to other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device as described in the drawings. For example, if the device in the drawings is inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" the other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0271] In addition, it should be noted that the use of the terms "first", "second", and the like do not have a special meaning, and therefore cannot be construed as limiting the scope of protection of the present application, unless otherwise stated.

[0272] The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A driving method of a dual-motor electric drive axle, characterized in that, The driving method is suitable for an electric drive axle architecture, which comprises a first electric machine (4) and a second electric machine (6) arranged symmetrically, and a planetary gear train, an output shaft of the first electric machine (4) is connected with a sun gear (1603) in the planetary gear train, the sun gear (1603) is selectively connected with a planet gear (1602) or a ring gear (1601) in the planetary gear train to complete gear shifting under the action of a gear shifting mechanism, and the driving method comprises: During operation of a target vehicle, a target vehicle speed and a target torque of the target vehicle within a predetermined distance are acquired, the target torque being a sum of torques of the first electric machine and the second electric machine; In a preset curve database, a function relationship linear curve conforming to the target vehicle speed and the target torque is searched; According to a corresponding relationship between the function relationship linear curve and a driving mode, a driving mode corresponding to the target vehicle speed and the target torque is obtained and marked to obtain a target driving mode; According to the target vehicle speed, a target total speed and a target total efficiency of the first electric machine and the second electric machine are determined; When a real-time speed of the target vehicle is the target vehicle speed and a sum of real-time speeds of the first electric machine and the second electric machine is the target total speed, an operation efficiency of the first electric machine and the second electric machine is switched to the target total efficiency, and the target vehicle is driven to operate in the target driving mode; The driving mode comprises a single-machine driving mode and a multi-machine driving mode, the single-machine driving mode is a mode in which the first electric machine or the second electric machine drives any gear position of a connected transmission, and the multi-machine driving mode is a mode in which the first electric machine drives any gear position of a connected transmission and the second electric machine drives any gear position of a connected transmission.

2. The driving method of the dual-motor electric drive axle according to claim 1, characterized in that, The step of searching, in a preset curve database, a function relationship linear curve conforming to the target vehicle speed and the target torque comprises: The preset curve database is constructed, the preset curve database comprises first function relationship linear curves corresponding to various first sub-modes in the single-machine driving mode and second function relationship linear curves corresponding to various second sub-modes in the multi-machine driving mode; The target vehicle speed is taken as a first search target, the preset curve database is traversed to determine an initial function relationship linear curve, and an initial function relationship linear curve library is formed; The target torque is taken as a second search target, the initial function relationship linear curve library is traversed to determine the function relationship linear curve.

3. The driving method of the dual-motor electric drive axle according to claim 2, characterized in that, The step of constructing the preset curve database comprises: obtain a historical characteristic parameter database, the historical characteristic parameter database comprising a plurality of first historical vehicle speeds of the target vehicle when the target vehicle is in the single-machine driving mode, and first historical torques corresponding to each of the first historical vehicle speeds, the first historical torque being a torque of the first electric machine or the second electric machine, the historical characteristic parameter database further comprising a plurality of second historical vehicle speeds of the target vehicle when the target vehicle is in the multi-machine driving mode, and second historical torques corresponding to each of the second historical vehicle speeds, the second historical torque being a sum of torques of the first electric machine and the second electric machine; obtain the first function relationship linear curve corresponding to each of the first sub-modes in the single-machine driving mode according to the plurality of first historical vehicle speeds and the first historical torques corresponding to each of the first historical vehicle speeds; obtain the second function relationship linear curve corresponding to each of the second sub-modes in the multi-machine driving mode according to the plurality of second historical vehicle speeds and the second historical torques corresponding to each of the second historical vehicle speeds.

4. The driving method of the dual-motor electric drive axle according to claim 3, characterized in that, The step of obtaining the first function relationship linear curve corresponding to each of the first sub-modes in the single-machine driving mode according to the plurality of first historical vehicle speeds and the first historical torques corresponding to each of the first historical vehicle speeds comprises: construct a first rectangular coordinate system with the first historical vehicle speed as the X-axis and the first historical torque as the Y-axis; form a plurality of first coordinate points in the first rectangular coordinate system according to the plurality of first historical vehicle speeds and the first historical torques corresponding to each of the first historical vehicle speeds; mark the first coordinate points in which the first historical torque is greater than or equal to a first set torque and less than or equal to a second set torque as a first group of coordinate points, and mark the first coordinate points in which the first historical torque is less than the first set torque as a second group of coordinate points; connect all coordinate points in the first group of coordinate points in sequence along the X-axis direction to obtain the first function relationship linear curve corresponding to the first electric machine or the second electric machine drivingly connected transmission in the first gear position in the single-machine driving mode, which is marked as a first single-machine function relationship linear curve; connect all coordinate points in the second group of coordinate points in sequence along the X-axis direction to obtain the first function relationship linear curve corresponding to the first electric machine or the second electric machine drivingly connected transmission in the second gear position in the single-machine driving mode, which is marked as a second single-machine function relationship linear curve.

5. The driving method of the dual-motor electric drive axle according to claim 4, characterized in that, The step of obtaining the second function relationship linear curve corresponding to each of the second sub-modes in the multi-machine driving mode according to the plurality of second historical vehicle speeds and the second historical torques corresponding to each of the second historical vehicle speeds comprises: construct a second rectangular coordinate system with the second historical vehicle speed as the X-axis and the second historical torque as the Y-axis; According to multiple second historical vehicle speeds and the second historical torques corresponding to each of the second historical vehicle speeds, multiple second coordinate points are formed in the second rectangular coordinate system; The second coordinate points in which the second historical torques are less than a third set torque are marked as a third group of coordinate points, the second coordinate points in which the second historical torques are greater than or equal to the third set torque and less than or equal to a fourth set torque are marked as a fourth group of coordinate points, and the second coordinate points in which the second historical torques are greater than the fourth set torque and less than or equal to a fifth set torque are marked as a fifth group of coordinate points; In the X-axis direction, all coordinate points in the third group of coordinate points are sequentially connected, to obtain a second function relationship linear curve corresponding to a case in which the first motor drivingly connected transmission is in second gear and the second motor drivingly connected transmission is in second gear in the multi-machine driving mode, which is marked as a first multi-machine function relationship linear curve; In the X-axis direction, all coordinate points in the fourth group of coordinate points are sequentially connected, to obtain a second function relationship linear curve corresponding to a case in which the first motor is in first gear and the second motor is in second gear in the multi-machine driving mode, which is marked as a second multi-machine function relationship linear curve; In the X-axis direction, all coordinate points in the fifth group of coordinate points are sequentially connected, to obtain a second function relationship linear curve corresponding to a case in which the first motor drivingly connected transmission is in first gear and the second motor drivingly connected transmission is in first gear in the multi-machine driving mode, which is marked as a third multi-machine function relationship linear curve.

6. The driving method of the dual-motor electric drive axle according to claim 4, characterized in that, The step of obtaining and marking the driving mode corresponding to the target vehicle speed and the target torque to obtain a target driving mode comprises: If the coordinate point of the target vehicle speed and the target torque in the first rectangular coordinate system is only in a region enclosed by the first single-machine function relationship linear curve and the second single-machine function relationship linear curve, the driving mode corresponding to the first single-machine function relationship linear curve is taken as the target driving mode.

7. The driving method of the dual-motor electric drive axle according to claim 2, wherein The preset curve database comprises the first single-machine function relationship linear curve, the second single-machine function relationship linear curve, the third multi-machine function relationship linear curve and the second multi-machine function relationship linear curve, and the step of obtaining and marking the driving mode corresponding to the target vehicle speed and the target torque to obtain a target driving mode comprises: When the target vehicle speed and the target torque are in the region enclosed by the first single-machine function relationship linear curve and the second single-machine function relationship linear curve and simultaneously in the region enclosed by the third multi-machine function relationship linear curve and the second multi-machine function relationship linear curve, a vehicle operating parameter is acquired, the vehicle operating parameter at least comprising the real-time vehicle speed and the rotation speeds of the first motor and the second motor; The first single-machine function relationship linear curve corresponds to a first energy consumption, and the third multi-machine function relationship linear curve corresponds to a second energy consumption, which are calculated according to the vehicle operating parameter, the target vehicle speed and the target torque. The driving mode corresponding to the minimum of the first energy consumption and the second energy consumption is taken as the target driving mode.

8. The driving method of the dual-motor electric drive axle according to claim 3, characterized in that, A first rectangular coordinate system is constructed with the first historical vehicle speed as the X axis and the first historical torque as the Y axis, and a second rectangular coordinate system is constructed with the second historical vehicle speed as the X axis and the second historical torque as the Y axis, the target driving mode corresponding to the target vehicle speed and the target torque is obtained and marked, and the target driving mode is obtained. When the coordinate point of the target vehicle speed and the target torque in the first rectangular coordinate system is in the area enclosed by the second single-machine function linear curve and the X axis of the first rectangular coordinate system, and at the same time, the coordinate point of the target vehicle speed and the target torque in the second coordinate system is in the area enclosed by the second multi-machine function linear curve and the X axis of the second rectangular coordinate system, the vehicle operating parameters are obtained, and the vehicle operating parameters at least include the real-time vehicle speed and the rotation speeds of the first motor and the second motor. The third energy consumption corresponding to the second single-machine function linear curve, the fourth energy consumption corresponding to the second multi-machine function linear curve, and the fifth energy consumption corresponding to the first multi-machine function linear curve are calculated according to the vehicle operating parameters, the target vehicle speed, and the target torque. The driving mode corresponding to the minimum of the third energy consumption, the fourth energy consumption, and the fifth energy consumption is taken as the target driving mode.

9. The driving method of the dual-motor electric drive axle according to claim 7, characterized in that, After the step of taking the driving mode corresponding to the minimum of the first energy consumption and the second energy consumption as the target driving mode, the following steps are included. When the second energy consumption is less than the first energy consumption, the maximum torque of the first motor is obtained. The maximum torque is divided into a plurality of first sub-torques by a set torque interval. The first motor rotation speed is kept unchanged, and the first motor energy consumption corresponding to each first sub-torque is calculated. The torque corresponding to the minimum of the plurality of first energy consumptions is determined as the current torque of the first motor. The current torque of the second motor is determined according to the target torque and the current torque of the first motor. A first torque request is sent to the controller of the first motor to make the first motor respond and run at the current torque of the first motor, and a second torque request is sent to the controller of the second motor to make the second motor respond and run at the current torque of the second motor.

10. The driving method of the dual-motor electric drive axle according to claim 9, characterized in that, The step of determining the current torque of the second motor according to the target torque and the current torque of the first motor includes: The torque difference between the target torque and the current torque of the first motor is calculated. The second motor rotation speed is kept unchanged, and the second motor energy consumption corresponding to all first sub-torques less than the torque difference in the plurality of first sub-torques is calculated. The torque corresponding to the minimum of the plurality of second energy consumptions is determined as the current torque of the second motor.

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