Control method, device, vehicle and storage medium of vehicle electric drive system

Abstract

The present application relates to a control method, device, vehicle and storage medium for a vehicle electric drive system, wherein the method includes: obtaining the current speed of the vehicle, and matching the optimal speed of the drive motor according to the current speed; matching the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear from the speed range of the reducer gear mapping relationship based on the optimal speed; controlling the reducer to operate according to the optimal gear and the reduction ratio corresponding to the optimal gear, while controlling the drive motor to operate at the optimal speed, so that the working efficiency of the electric drive system is the highest. Therefore, through the design of the reducer speed ratio and gear, the drive motor is always operated in the high-efficiency zone, so that the electric drive system operates in the high-efficiency zone within the full vehicle speed range, solving the problem that when the vehicle is running at medium and low speeds or high speeds, the vehicle's continuous starting mileage is reduced due to the electric drive system operating in the non-efficient zone, which can greatly improve the vehicle's continuous starting mileage and reduce the cost of the vehicle.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a control method, device, vehicle and storage medium for a vehicle electric drive system. Background Art

[0002] The higher the efficiency of the electric drive system, the greater the vehicle's range. Under the current conditions of material performance and production process level, the efficiency of the electric drive system itself has been improved to the limit level, but the electric drive system itself has certain losses, which are caused by the objective losses of the motor, electronic control and reducer itself. Therefore, the motor, electronic control and reducer are all trying to improve their own efficiency.

[0003] In the related technology, the reducer achieves speed reduction and torque increase and adjusts the motor operating range through the reduction ratio and gear position. Currently, most reducers are single-speed ratio or two-speed ratio, and the ability to adjust the motor operating range is weak. When the vehicle is running, the electric drive system only operates in the high-efficiency zone within a very narrow speed range, and the electric drive system operates in the non-efficient zone for most of the remaining speed range. The electric drive system operates in the non-efficient zone, and the loss is large, which reduces the vehicle's continuous mileage, which needs to be solved urgently. Summary of the invention

[0004] The present application provides a control method, device, vehicle and storage medium for a vehicle electric drive system to solve the problem that when the vehicle is running at medium or low speeds or high speeds, the vehicle's range is reduced due to the electric drive system running in a non-efficient area. The vehicle's range can be greatly improved and the cost of the vehicle can be reduced.

[0005] A first aspect of the present application provides a method for controlling a vehicle electric drive system, comprising the following steps:

[0006] Acquire the current speed of the vehicle, and match the optimal speed of the drive motor according to the current speed;

[0007] Based on the speed range in which the optimal speed is located, matching the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear from a speed range-reducer gear mapping relationship; and

[0008] While controlling the reducer to operate according to the optimal gear and the reduction ratio corresponding to the optimal gear, the drive motor is controlled to operate at the optimal speed, so that the working efficiency of the electric drive system is the highest.

[0009] Optionally, before matching the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear from the speed range-reducer gear mapping relationship, the method further includes:

[0010] Determining a target vehicle speed range of the vehicle, and acquiring a first speed range of the electric drive system corresponding to the target vehicle speed range;

[0011] Determining a target efficiency range of the motor system and a second speed range corresponding to the target efficiency range of the motor system according to an efficiency MAP diagram of the motor system;

[0012] The reduction ratios of the multiple gears of the reducer and the speed range of the electric drive system corresponding to each gear are calculated according to the target vehicle speed range, the first speed range and the second speed range, and the speed range-reducer gear mapping relationship is determined according to the multiple gear reduction ratios and the speed range corresponding to each gear.

[0013] Optionally, before determining the speed range-speed reducer gear mapping relationship according to the multiple gear reduction ratios and the speed range corresponding to each gear, the method further includes:

[0014] Determining the power torque parameter of the electric drive system according to the multiple gear reduction ratios and the speed range corresponding to each gear;

[0015] The efficiency MAP diagram of the motor system is adjusted according to the power torque parameter, and the efficiency MAP diagram of the motor system is replaced with the efficiency MAP diagram of the new motor system until the target requirement is met, thereby obtaining the speed range-reducer gear mapping relationship.

[0016] Optionally, the calculating, according to the target vehicle speed range, the first speed range and the second speed range, of multiple gear reduction ratios of the reducer and a speed range of the electric drive system corresponding to each gear includes:

[0017] The reduction ratio of the reducer at each gear position is obtained according to the ratio of the minimum speed value of the second speed interval to the minimum speed value of the speed interval corresponding to each gear position;

[0018] Obtaining the maximum value of the speed interval corresponding to each gear according to the product of the maximum speed of the second speed interval and the speed ratio of each gear;

[0019] Among them, the speed ranges corresponding to multiple gears constitute the first speed range.

[0020] Optionally, a lower limit value of the target efficiency range is a preset value, and an upper limit value of the target efficiency range is determined by the electric drive system.

[0021] A second aspect of the present application provides a control device for a vehicle electric drive system, including:

[0022] An acquisition module, used to acquire the current speed of the vehicle and match the optimal speed of the drive motor according to the current speed;

[0023] a matching module, configured to match the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear from a mapping relationship between the speed range and the gear of the reducer based on the speed range in which the optimal speed is located; and

[0024] The control module is used to control the reducer to operate according to the optimal gear and the reduction ratio corresponding to the optimal gear, and control the drive motor to operate at the optimal speed, so that the working efficiency of the electric drive system is the highest.

[0025] Optionally, before matching the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear from the speed range-reducer gear mapping relationship, the matching module is further used to:

[0026] Determining a target vehicle speed range of the vehicle, and acquiring a first speed range of the electric drive system corresponding to the target vehicle speed range;

[0027] The target efficiency range of the motor system and the second speed range corresponding to the target efficiency range of the motor system are determined according to the efficiency MAP diagram of the motor system; the reduction ratios of multiple gears of the reducer and the speed range of the electric drive system corresponding to each gear are calculated according to the target vehicle speed range, the first speed range and the second speed range, and the speed range-reducer gear mapping relationship is determined according to the reduction ratios of the multiple gears and the speed range corresponding to each gear.

[0028] Optionally, before determining the speed range-speed reducer gear mapping relationship according to the multiple gear reduction ratios and the speed range corresponding to each gear, the matching module is further used to:

[0029] Determining the power torque parameter of the electric drive system according to the multiple gear reduction ratios and the speed range corresponding to each gear;

[0030] The efficiency MAP diagram of the motor system is adjusted according to the power torque parameter, and the efficiency MAP diagram of the motor system is replaced with the efficiency MAP diagram of the new motor system until the target requirement is met, thereby obtaining the speed range-reducer gear mapping relationship.

[0031] Optionally, the matching module is further used to:

[0032] The reduction ratio of the reducer at each gear position is obtained according to the ratio of the minimum speed value of the second speed interval to the minimum speed value of the speed interval corresponding to each gear position;

[0033] Obtaining the maximum value of the speed interval corresponding to each gear according to the product of the maximum speed of the second speed interval and the speed ratio of each gear;

[0034] Among them, the speed ranges corresponding to multiple gears constitute the first speed range.

[0035] Optionally, the lower limit value of the target efficiency range is a preset value, and the upper limit value of the target efficiency range is determined by the electric drive system.

[0036] A third aspect of the present application provides a vehicle, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are configured to execute the control method of the vehicle electric drive system as described in the above embodiment.

[0037] The fourth aspect of the present application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the control method of the vehicle electric drive system as described in the above embodiments.

[0038] Therefore, by obtaining the current speed of the vehicle, and matching the optimal speed of the drive motor according to the current speed, and based on the speed range where the optimal speed is located, matching the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear from the speed range reducer gear mapping relationship, and controlling the reducer to operate according to the optimal gear and the reduction ratio corresponding to the optimal gear, while controlling the drive motor to operate at the optimal speed, the working efficiency of the electric drive system is maximized. Therefore, through the matching design of the reducer speed ratio and gear, the motor system always runs in the high-efficiency zone, so that the electric drive system runs in the high-efficiency zone within the full vehicle speed range, solving the problem that when the vehicle is running at medium and low speeds or high speeds, the vehicle's continuous mileage is reduced due to the electric drive system running in the non-efficient zone, which can greatly improve the vehicle's continuous mileage and reduce the cost of the vehicle.

[0039] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0041] Figure 1 It is the transmission schematic diagram of the electric drive system;

[0042] Figure 2 This is a schematic diagram of the efficiency MAP of the electric drive system;

[0043] Figure 3 It is a schematic diagram of a single-speed parallel shaft reducer in the related art;

[0044] Figure 4 It is a schematic diagram of the operating point distribution efficiency MAP of a single-speed electric drive system in the related art;

[0045] Figure 5 A flow chart of a method for controlling a vehicle electric drive system according to an embodiment of the present application;

[0046] Figure 6 A flowchart of matching a reducer and a motor system of an electric drive system according to an embodiment of the present application;

[0047] Figure 7 A schematic diagram of an example of calculating the motor system efficiency MAP according to an embodiment of the present application;

[0048] Figure 8 A schematic diagram of the CLTC (China light-duty vehicle test cycle) operating point efficiency MAP at each gear position of an electric drive system provided according to an embodiment of the present application;

[0049] Fig. 9 A block diagram of a control device for a vehicle electric drive system provided according to an embodiment of the present application;

[0050] Fig.10 It is a schematic diagram of the structure of a vehicle provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0051] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0052] The following describes a control method, device, vehicle, and storage medium for a vehicle electric drive system according to an embodiment of the present application with reference to the accompanying drawings.

[0053] Before introducing the control method of the vehicle electric drive system of the embodiment of the present application, the electric drive system, the losses existing in the electric drive system, and the operating principles and shortcomings of the reducer in the related technology are briefly introduced.

[0054] like Figure 1 As shown, Figure 1This is a transmission diagram of the electric drive system. The vehicle's electric drive system includes several components, such as the motor, motor controller, and reducer. The motor has the functions of driving and generating electricity. When driving, it consumes electrical energy and outputs torque and speed. When generating electricity, it is driven by the wheels to rotate, converting the kinetic energy of the wheels into electrical energy and storing it in the battery. The motor controller receives instructions from the vehicle controller and controls the motor to perform specific driving or generating functions. The reducer has the functions of reducing speed, increasing torque, and adjusting the operating range of the motor. It transmits torque and speed from the motor to the half-axle, and then to the wheels to drive the vehicle forward. The reducer can improve the acceleration ability of the vehicle and increase the vehicle's cruising range by adjusting the operating range of the motor system.

[0055] The electric drive system itself has certain losses, which are caused by the objective losses of the motor, electronic control and reducer. The loss of the electronic control is caused by the heat of IGBT (Insulated Gate Bipolar Transistor), capacitors and resistors, and the maximum efficiency is not less than 98%; the loss of the reducer mainly includes gear loss, bearing loss, oil seal loss, etc., and the maximum efficiency is not less than 96%; the loss of the motor is mainly copper loss, iron loss, bearing loss, etc., and the maximum efficiency is not less than 96%, and the efficiency gap at different operating points is large. The higher the efficiency of the electric drive system, the greater the vehicle's cruising range; therefore, the motor, electronic control, and reducer are all trying to improve their own efficiency. Under the current conditions of material properties and production process levels, the efficiency of the electric drive system itself has been improved to the limit level. Among them, the efficiency MAP diagram of the electric drive system can be shown as follows Figure 2 shown.

[0056] In the related art, the reducers of most passenger car electric drive systems are single-gear single-speed ratio, such as Figure 3 As shown, Figure 3 This is a schematic diagram of the structure of a single-speed parallel shaft reducer. The reducers of some commercial vehicles or high-end passenger cars are two-speed and two-speed ratios, and the ability to adjust the motor operation range is weak. When the vehicle is running, the electric drive system only runs in the high-efficiency zone in a very narrow speed range, and the electric drive system runs in the non-efficient zone in most other speed ranges. When electric vehicles are running in urban areas, they often need to run in the low-speed range of 10-40km / h, and when running on highways, they need to run in the high-speed range of 80-120km / h. In these two ranges, the efficiency of the electric drive system of electric vehicles is generally in the non-efficient zone.

[0057] However, since most electric drive systems of electric vehicles use single-speed fixed-speed ratio reducers, the ability to adjust the operating range of the motor system is weak, causing many operating points of the electric drive system to operate in the non-efficient area (CLTC operating conditions). Figure 4As shown in the figure, many operating points are located in the area with an efficiency lower than 85%. When the wheel speed is lower than 348rpm or higher than 1161rpm, the electric drive system operates in a non-efficient area, resulting in large losses and thus reducing the vehicle's continuous mileage. That is, when the vehicle is running at low or medium speeds or at high speeds, the electric drive system operates in a non-efficient area, resulting in a reduced continuous mileage.

[0058] The present application proposes a control method for a vehicle electric drive system based on the above-mentioned problems. In the method, the motor system is always operated in the high-efficiency zone through the design of the speed ratio and gear of the reducer, so that the electric drive system operates in the high-efficiency zone within the full vehicle speed range. In this way, the problems of large power loss and low continuous mileage caused by the vehicle always running in the non-efficient zone are solved, which can greatly improve the vehicle's continuous mileage and reduce the cost of the vehicle.

[0059] Specifically, Figure 5 A flow chart of a control method for a vehicle electric drive system provided in an embodiment of the present application.

[0060] like Figure 5 As shown, the control method of the vehicle electric drive system includes the following steps:

[0061] In step S501, the current speed of the vehicle is acquired, and the optimal speed of the driving motor is matched according to the current speed.

[0062] It should be understood that the embodiment of the present application may preset a mapping relationship between the vehicle speed and the rotational speed of the drive motor. After obtaining the current speed of the vehicle, the embodiment of the present application may match the optimal rotational speed of the drive motor by querying the above-mentioned mapping relationship.

[0063] The current speed of the vehicle may be obtained by a speed sensor or by other means, such as a speed meter, which is not specifically limited here.

[0064] In step S502, based on the speed range in which the optimal speed is located, the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear are matched from the speed range-reducer gear mapping relationship.

[0065] That is to say, the embodiment of the present application can predetermine the speed range-reducer gear mapping relationship. After obtaining the optimal speed of the drive motor in step S501, the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear can be obtained based on the above-mentioned speed range-reducer gear mapping relationship.

[0066] For ease of understanding, the following describes in detail how to predetermine the speed range-reducer gear mapping relationship.

[0067] Optionally, in some embodiments, before matching the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear from the speed range-reducer gear mapping relationship, it also includes: determining the target speed range of the vehicle, and obtaining the first speed range of the electric drive system corresponding to the target speed range; determining the target efficiency range of the motor system and the second speed range corresponding to the target efficiency range of the motor system according to the efficiency MAP diagram of the motor system; calculating the reduction ratios of multiple gears of the reducer and the speed range of the electric drive system corresponding to each gear according to the target speed range, the first speed range and the second speed range, and determining the speed range-reducer gear mapping relationship according to the multiple gear reduction ratios and the speed range corresponding to each gear.

[0068] Optionally, in some embodiments, the lower limit of the target efficiency range is a preset value, and the upper limit of the target efficiency range is determined by the electric drive system. Preferably, the lower limit of the target efficiency range is a preset value, which may be 90%-92%.

[0069] Specifically, the target vehicle speed range can be set by the user. Since the selection of the minimum vehicle speed will affect the size of the first gear reduction ratio, the smaller the minimum vehicle speed, the larger the first gear reduction ratio, so the minimum vehicle speed can be set to 10km / h; then the first speed range of the drive motor corresponding to the target vehicle speed range can be determined according to the mapping relationship between the vehicle speed and the speed of the drive motor.

[0070] Furthermore, the efficiency MAP diagram of the motor system can be obtained from the selected motor system, and the embodiment of the present application can determine the boundary value (i.e., the high-efficiency interval) of the efficient operation of the drive motor and the motor speed range at the boundary (i.e., the second speed interval corresponding to the high-efficiency interval) according to the efficiency MAP diagram of the motor system. It should be noted that the larger the maximum efficiency value of the drive motor is, the more gears the reducer will have, and the greater the reduction ratio of the first gear will be.

[0071] Further, in some embodiments, the reduction ratios of multiple gears of the reducer and the speed range of the electric drive system corresponding to each gear are calculated according to the target vehicle speed range, the first speed range and the second speed range, including: obtaining the reduction ratio of the reducer in each gear according to the ratio of the minimum speed value of the second speed range to the minimum speed value of the speed range corresponding to each gear; obtaining the maximum value of the speed range corresponding to each gear according to the product of the maximum speed of the second speed range and the speed ratio of each gear; wherein the speed ranges corresponding to multiple gears constitute the first speed range.

[0072] Specifically, after determining the above data, the embodiment of the present application can obtain the reduction ratio of the reducer in the first gear according to the ratio of the minimum speed value of the second speed interval to the minimum speed value of the speed interval corresponding to the first gear; obtain the maximum value of the speed interval corresponding to the first gear according to the product of the maximum speed value of the second speed interval and the reduction ratio of the first gear;

[0073] Furthermore, the embodiment of the present application can obtain the reduction ratio of the reducer in the second gear according to the ratio of the minimum speed value of the second speed range to the minimum speed value of the speed range corresponding to the second gear (that is, the maximum value of the speed range corresponding to the first gear); obtain the maximum value of the speed range corresponding to the second gear according to the product of the maximum speed of the second speed range and the reduction ratio of the second gear; ..., determine the reduction ratio of each gear of the reducer and the speed range of the drive motor in each gear in turn until the first speed range is covered.

[0074] Furthermore, in some embodiments, before determining the speed interval-reducer gear mapping relationship based on multiple gear reduction ratios and the speed interval corresponding to each gear, it also includes: determining the power torque parameters of the electric drive system based on multiple gear reduction ratios and the speed interval corresponding to each gear; adjusting the efficiency MAP diagram of the motor system based on the power torque parameters, and replacing the efficiency MAP diagram of the motor system with the new efficiency MAP of the motor system until the target requirements are met, and obtaining the speed interval-reducer gear mapping relationship. In order to facilitate those skilled in the art to further understand the matching process of the reducer and the drive motor in the embodiment of the present application, the following is combined with Figure 6 Provide detailed explanation.

[0075] like Figure 6 As shown, Figure 6 The flowchart of matching the reducer and the drive motor according to one embodiment of the present application mainly includes the following steps:

[0076] S601, determining a vehicle speed range (V1-V2) for efficient operation of the vehicle, and determining a rotation speed (N1-N) of the electric drive system corresponding to the vehicle speed.

[0077] S602, providing the efficiency MAP of the motor system, determining the boundary value A of the high-efficiency operation of the motor system, and determining the motor speed (n1-n2) of the high-efficiency boundary of the motor system.

[0078] S603, determining the reduction ratio of the first gear of the reducer r1=n1 / N1;

[0079] Determine the speed range of the first gear of the electric drive system (0-N2), N2 = n2*r1;

[0080] Determine the reduction ratio of the second gear of the reducer r2 = n1 / N2;

[0081] Determine the speed range of the second gear of the electric drive system (N2-N3), N3 = n2*r2; ...

[0082] The reduction ratio of each gear of the reducer and the speed range of the drive motor in each gear are determined in sequence until the first speed range, that is, the speed range (N1-N) of the electric drive system is covered.

[0083] S604, calculating the power and economy of the vehicle.

[0084] S605, adjusting the parameters such as power torque of the motor system, and jumping to execute step S602 to adaptively adjust the efficiency MAP of the drive motor.

[0085] It should be noted that when calculating the vehicle's power and economy, the embodiment of the present application optimizes the power-torque parameters of the motor system based on the calculation results, and performs a new round of optimization adjustment of the reducer speed ratio and gear position. This is performed two to three times to ultimately determine the optimal matching result between the reducer and the drive motor of the electric drive system.

[0086] The process of determining the speed ratio and gear position of the reducer is described in detail below with reference to a specific embodiment.

[0087] Specifically, as shown in Table 1, Table 1 is a table of calculation examples for matching the reducer and the drive motor; Figure 7 It is a schematic diagram of the efficiency MAP of the motor system. Figure 8 This is the CLTC operating point efficiency MAP diagram for the electric drive system at each gear. As can be seen from the above diagram, most of the CLTC operating points are in the high-efficiency zone. Compared with the single-gear electric drive assembly, the efficiency of the CLTC operating point has been greatly improved. For users, it can be ensured that the electric drive system operates in the high-efficiency zone within the full speed range of the vehicle.

[0088] Table 1

[0089] Minimum vehicle speed for efficient operation V1 (km / h) 10 Efficient operation maximum speed V2 (km / h) 120 The minimum speed N1 (rpm) for efficient operation of the electric drive system 78.71 Maximum speed at which the electric drive system operates efficiently N (rpm) 944.54 Motor system high efficiency zone boundary value A(%) 93 Motor speed lower limit n1(rpm) 4000 Motor speed limit n2 (rpm) 8000 First gear reduction ratio r1 50.82 Maximum speed of the electric drive system in the first gear N2 (rpm) 157.42 The second gear reduction ratio r2 25.41 Maximum speed of the electric drive system in the second gear N3 (rpm) 314.84 The third gear reduction ratio is r3 12.70 Maximum speed of the electric drive system in third gear N4 (rpm) 629.68 Fourth gear reduction ratio r4 6.35 Maximum speed of the fourth gear of the electric drive system N5 (rpm) 1259.36

[0090] In step S503, the reducer is controlled to operate according to the optimal gear and the reduction ratio corresponding to the optimal gear, and the drive motor is controlled to operate at the optimal speed, so that the working efficiency of the electric drive system is the highest.

[0091] Therefore, the embodiment of the present application can control the reducer to operate according to the optimal gear and the reduction ratio corresponding to the optimal gear, while controlling the drive motor to operate at the optimal speed, thereby ensuring that the vehicle's electric drive system is in a high-efficiency operating area.

[0092] According to the control method of the vehicle electric drive system proposed in the embodiment of the present application, by obtaining the current speed of the vehicle, and matching the optimal speed of the drive motor according to the current speed, and based on the speed range where the optimal speed is located, matching the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear from the speed range reducer gear mapping relationship, and controlling the reducer to operate according to the optimal gear and the reduction ratio corresponding to the optimal gear, while controlling the drive motor to operate at the optimal speed, the working efficiency of the electric drive system is maximized. Therefore, through the matching design of the reducer speed ratio and the gear, the motor system is always operated in the high-efficiency zone, so that the electric drive system operates in the high-efficiency zone within the full vehicle speed range, solving the problem that when the vehicle is running at medium and low speeds or high speeds, the vehicle's continuous mileage is reduced due to the electric drive system running in the non-efficient zone, which can greatly improve the vehicle's continuous mileage and reduce the cost of the vehicle.

[0093] Next, the control device of the vehicle electric drive system proposed in accordance with the embodiment of the present application will be described with reference to the accompanying drawings.

[0094] Fig. 9 It is a block diagram of a control device for a vehicle electric drive system according to an embodiment of the present application.

[0095] like Fig. 9 As shown, the control device 10 of the vehicle electric drive system includes: an acquisition module 100 , a matching module 200 and a control module 300 .

[0096] The acquisition module 100 is used to acquire the current speed of the vehicle and match the optimal speed of the drive motor according to the current speed;

[0097] A matching module 200, for matching the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear from a mapping relationship between the speed range and the gear of the reducer based on the speed range in which the optimal speed is located; and

[0098] The control module 300 is used to control the reducer to operate according to the optimal gear and the reduction ratio corresponding to the optimal gear, and control the drive motor to operate at the optimal speed, so that the working efficiency of the electric drive system is the highest.

[0099] Optionally, in some embodiments, before matching the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear from the speed range-reducer gear mapping relationship, the matching module 200 is further used to:

[0100] Determining a target vehicle speed range of the vehicle, and acquiring a first speed range of the electric drive system corresponding to the target vehicle speed range;

[0101] The target efficiency range of the motor system and the second speed range corresponding to the target efficiency range of the motor system are determined according to the efficiency MAP diagram of the motor system; the reduction ratios of multiple gears of the reducer and the speed range of the electric drive system corresponding to each gear are calculated according to the target vehicle speed range, the first speed range and the second speed range, and the speed range-reducer gear mapping relationship is determined according to the reduction ratios of multiple gears and the speed range corresponding to each gear.

[0102] Optionally, in some embodiments, before determining the speed range-speed reducer gear mapping relationship according to the multiple gear reduction ratios and the speed range corresponding to each gear, the matching module 200 is further configured to:

[0103] Determining power torque parameters of the electric drive system according to multiple gear reduction ratios and a speed range corresponding to each gear;

[0104] The efficiency MAP diagram of the motor system is adjusted according to the power torque parameter, and the efficiency MAP diagram of the motor system is replaced by the new efficiency MAP diagram of the motor system until the target requirement is met, thereby obtaining a speed range-reducer gear mapping relationship. Optionally, in some embodiments, the matching module 200 is further used to:

[0105] The reduction ratio of the reducer at each gear position is obtained according to the ratio of the minimum speed value of the second speed interval to the minimum speed value of the speed interval corresponding to each gear position;

[0106] The maximum value of the speed interval corresponding to each gear is obtained according to the product of the maximum speed of the second speed interval and the speed ratio of each gear;

[0107] Among them, the speed ranges corresponding to multiple gears constitute the first speed range.

[0108] Optionally, in some embodiments, the lower limit value of the target efficiency range is a preset value, and the upper limit value of the target efficiency range is determined by the electric drive system.

[0109] It should be noted that the above explanation of the embodiment of the control method of the vehicle electric drive system is also applicable to the control device of the vehicle electric drive system of this embodiment, which will not be repeated here.

[0110] According to the control device of the vehicle electric drive system proposed in the embodiment of the present application, by obtaining the current speed of the vehicle, and matching the optimal speed of the drive motor according to the current speed, and based on the speed range where the optimal speed is located, matching the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear from the speed range reducer gear mapping relationship, and controlling the reducer to operate according to the optimal gear and the reduction ratio corresponding to the optimal gear, while controlling the drive motor to operate at the optimal speed, so that the working efficiency of the electric drive system is the highest. Therefore, through the matching design of the reducer speed ratio and the gear, the motor system is always operated in the high-efficiency zone, so that the electric drive system operates in the high-efficiency zone within the full vehicle speed range, solving the problem that when the vehicle is running at medium and low speeds or high speeds, the vehicle's continuous starting mileage is reduced due to the electric drive system running in the non-efficient zone, which can greatly improve the vehicle's continuous starting mileage and reduce the cost of the vehicle.

[0111] Fig.10 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application. The vehicle may include:

[0112] A memory 1001 , a processor 1002 , and a computer program stored in the memory 1001 and executable on the processor 1002 .

[0113] When the processor 1002 executes the program, the control method of the vehicle electric drive system provided in the above embodiment is implemented.

[0114] Furthermore, the vehicle also includes:

[0115] The communication interface 1003 is used for communication between the memory 1001 and the processor 1002 .

[0116] The memory 1001 is used to store computer programs that can be executed on the processor 1002 .

[0117] The memory 1001 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0118] If the memory 1001, the processor 1002 and the communication interface 1003 are implemented independently, the communication interface 1003, the memory 1001 and the processor 1002 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig.10 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0119] Optionally, in a specific implementation, if the memory 1001, the processor 1002 and the communication interface 1003 are integrated on a chip, the memory 1001, the processor 1002 and the communication interface 1003 can communicate with each other through an internal interface.

[0120] The processor 1002 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0121] An embodiment of the present application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned control method for the vehicle electric drive system.

[0122] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0123] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0124] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0125] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0126] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

Claims

1. A control method for a vehicle electric drive system, characterized in that: The following steps are involved: Acquire the current speed of the vehicle, and match the optimal speed of the drive motor according to the current speed; Based on the speed range in which the optimal speed is located, matching the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear from a speed range-reducer gear mapping relationship; as well as While controlling the reducer to operate according to the optimal gear and the reduction ratio corresponding to the optimal gear, controlling the drive motor to operate at the optimal speed, so that the working efficiency of the electric drive system is the highest, wherein before matching the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear from the speed range-reducer gear mapping relationship, it also includes: Determining a target vehicle speed range of the vehicle, and acquiring a first speed range of the electric drive system corresponding to the target vehicle speed range; Determine, according to an efficiency MAP diagram of the motor system, a target efficiency range of the motor system and a second speed range corresponding to the target efficiency range of the motor system; The reduction ratios of the multiple gears of the reducer and the speed range of the electric drive system corresponding to each gear are calculated according to the target vehicle speed range, the first speed range and the second speed range, and the speed range-reducer gear mapping relationship is determined according to the multiple gear reduction ratios and the speed range corresponding to each gear.

2. The method according to claim 1, characterized in that Before determining the speed range-speed reducer gear mapping relationship according to the multiple gear reduction ratios and the speed range corresponding to each gear, the method further includes: Determining the power torque parameter of the electric drive system according to the multiple gear reduction ratios and the speed range corresponding to each gear; The efficiency MAP diagram of the motor system is adjusted according to the power torque parameter, and the efficiency MAP diagram of the motor system is replaced with the efficiency MAP diagram of the new motor system until the target requirement is met, thereby obtaining the speed range-reducer gear mapping relationship.

3. The method according to claim 1, characterized in that The calculating, according to the target vehicle speed range, the first speed range and the second speed range, of multiple gear reduction ratios of the reducer and a speed range of the electric drive system corresponding to each gear includes: The reduction ratio of the reducer at each gear position is obtained according to the ratio of the minimum speed value of the second speed interval to the minimum speed value of the speed interval corresponding to each gear position; Obtaining the maximum value of the speed interval corresponding to each gear according to the product of the maximum speed of the second speed interval and the speed ratio of each gear; Among them, the speed ranges corresponding to multiple gears constitute the first speed range.

4. The method according to any one of claims 1 to 3, characterized in that: The lower limit value of the target efficiency range is a preset value, and the upper limit value of the target efficiency range is determined by the electric drive system.

5. A control device for a vehicle electric drive system, characterized in that: include: An acquisition module, used to acquire the current speed of the vehicle and match the optimal speed of the drive motor according to the current speed; A matching module, for matching the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear from a mapping relationship between the speed range and the gear of the reducer based on the speed range in which the optimal speed is located; as well as A control module is used to control the reducer to operate according to the optimal gear and the reduction ratio corresponding to the optimal gear, and control the drive motor to operate at the optimal speed, so that the working efficiency of the electric drive system is the highest, wherein before matching the optimal gear of the reducer and the reduction ratio corresponding to the optimal gear from the speed range-reducer gear mapping relationship, the matching module is also used to: Determining a target vehicle speed range of the vehicle, and acquiring a first speed range of the electric drive system corresponding to the target vehicle speed range; Determine, according to an efficiency MAP diagram of the motor system, a target efficiency range of the motor system and a second speed range corresponding to the target efficiency range of the motor system; The reduction ratios of the multiple gears of the reducer and the speed range of the electric drive system corresponding to each gear are calculated according to the target vehicle speed range, the first speed range and the second speed range, and the speed range-reducer gear mapping relationship is determined according to the multiple gear reduction ratios and the speed range corresponding to each gear.

6. The device according to claim 5, characterized in that Before determining the speed range-speed reducer gear mapping relationship according to the multiple gear reduction ratios and the speed range corresponding to each gear, the matching module is further used to: Determining the power torque parameter of the electric drive system according to the multiple gear reduction ratios and the speed range corresponding to each gear; The efficiency MAP diagram of the motor system is adjusted according to the power torque parameter, and the efficiency MAP diagram of the motor system is replaced with the efficiency MAP diagram of the new motor system until the target requirement is met, thereby obtaining the speed range-reducer gear mapping relationship.

7. A vehicle, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the control method of the vehicle electric drive system as described in any one of claims 1 to 4.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the control method of the vehicle electric drive system as described in any one of claims 1 to 4.

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