WO2022037651A1 - Four-wheel drive electric vehicle power distribution method and apparatus - Google Patents

Abstract

A four-wheel drive electric vehicle power distribution method and apparatus. At least two motors are mounted on a four-wheel drive electric vehicle. The method comprises: during the operation of the vehicle, obtaining a required torque of a driver for operating the vehicle and the real-time rotational speeds of the motors; from a loss power meter corresponding to each motor, obtaining the loss power of a corresponding motor when the motor generates different torques under the real-time rotational speed; taking the sum value of the torques as the required torque, randomly selecting one torque from the obtained torques corresponding to each motor for combination, and calculating the sum value of the loss power corresponding to each torque combination; and according to the sum value of the loss power corresponding to each torque combination, determining the torque distribution proportion of the required torque in the at least two motors, so that the sum value of the loss power corresponding to the determined torque distribution proportion meets a preset requirement.

Description

Four-wheel drive electric vehicle power distribution method and device

This application claims the priority of the Chinese patent application filed on August 19, 2020 with the application number 202010837437.6 and the invention titled "Method and Device for Power Distribution of Four-wheel Drive Electric Vehicle", the entire contents of which are incorporated by reference in this application.

technical field

This document relates to the technical field of vehicles, in particular to a method and device for power distribution of a four-wheel drive electric vehicle.

Background technique

At present, the power distribution method of four-wheel-drive electric vehicles is: after the vehicle controller (VCU) analyzes the torque required by the driver, it is simply distributed to the motor on the vehicle through an equal ratio or other empirical ratios. Conventional four-wheel-drive electric vehicles will Install two motors, the front and rear motors. The front and rear motors adjust the output torque according to the VCU command. This torque distribution method will lead to low efficiency of the motor system, which will adversely affect the energy consumption and battery life of the entire vehicle.

SUMMARY OF THE INVENTION

This specification provides a power distribution method and device for an electric four-wheel drive vehicle, which is used to solve the problem of low efficiency of the motor system of the four-wheel drive electric vehicle caused by the existing torque distribution method.

To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

In a first aspect, the embodiments of the present specification provide a power distribution method for a four-wheel-drive electric vehicle, where at least two motors are installed on the four-wheel-drive electric vehicle. The method includes:

During the operation of the vehicle, obtain the required torque of the driver to operate the vehicle and the real-time rotational speed of the motor;

From the loss power table corresponding to each of the motors, obtain the loss power when the corresponding motors generate different torques at the real-time rotational speed;

According to the torque and the value of the required torque, from the obtained torque corresponding to each of the motors, arbitrarily select a torque to combine, and calculate the loss power and value corresponding to each torque combination;

According to the loss power sum value corresponding to each torque combination, the torque distribution ratio of the required torque in the at least two electric machines is determined, so that the loss power sum value corresponding to the determined torque distribution ratio meets the preset requirement.

In a second aspect, the embodiments of this specification provide a power distribution device for a four-wheel drive electric vehicle, where at least two motors are installed on the four-wheel drive electric vehicle. The device includes:

The data acquisition module, during the operation of the vehicle, acquires the required torque of the driver to operate the vehicle and the real-time rotational speed of the motor;

The torque acquisition module acquires, from the loss power table corresponding to each of the motors, the loss power of the corresponding motor when different torques are generated at the real-time rotational speed;

The combination calculation module, according to the torque and the value of the required torque, arbitrarily selects a torque to combine from the obtained torque corresponding to each of the motors, and calculates the loss power and value corresponding to each torque combination;

The torque distribution module determines the torque distribution ratio of the demanded torque in the at least two motors according to the loss power and value corresponding to each torque combination, so that the loss power and value corresponding to the determined torque distribution ratio meet the predetermined requirements. set requirements.

The power distribution method and device for a four-wheel-drive electric vehicle provided by the embodiments of this specification. At least two motors are installed on the four-wheel-drive electric vehicle. During the running of the vehicle, the required torque of the driver to operate the vehicle and the real-time rotation speed of the motors are obtained. ; From the loss power table corresponding to each motor, obtain the loss power of the corresponding motor when it produces different torques at the real-time speed; according to the torque value and the required torque, from the obtained torque corresponding to each motor, arbitrarily select a torque Make combinations, and calculate the loss power and value corresponding to each torque combination; determine the torque distribution ratio of the required torque in at least two motors according to the loss power and value corresponding to each torque combination, so that the determined torque distribution ratio The corresponding loss power and value meet the preset requirements, so as to realize the reasonable distribution of the power of the whole vehicle, improve the efficiency of the motor system of the four-wheel drive electric vehicle, and reduce the adverse impact on energy consumption and battery life.

Description of drawings

In order to more clearly illustrate one or more embodiments of the present specification or the technical solutions in the prior art, the following briefly introduces the accompanying drawings used in the description of the embodiments or the prior art. Obviously, in the following description The accompanying drawings are only some embodiments described in this specification, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic diagram of an application scenario of a power distribution method for a four-wheel-drive electric vehicle provided by an embodiment of the present specification;

FIG. 2 is a schematic flow chart 1 of a power distribution method for a four-wheel drive electric vehicle provided by an embodiment of the present specification;

FIG. 3 is a second schematic flow chart of a power distribution method for a four-wheel drive electric vehicle provided by an embodiment of the present specification;

FIG. 4 is a schematic flow chart 3 of a power distribution method for a four-wheel drive electric vehicle provided by an embodiment of the present specification;

FIG. 5 is a fourth schematic flowchart of a power distribution method for a four-wheel drive electric vehicle provided by an embodiment of the present specification;

FIG. 6 is a schematic flow chart 5 of a power distribution method for a four-wheel drive electric vehicle provided by an embodiment of the present specification;

FIG. 7 is a schematic structural diagram of a power distribution device for a four-wheel drive electric vehicle according to an embodiment of the present specification.

detailed description

In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present specification, the technical solutions in the embodiments of the present specification will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present specification. The described embodiments are only some of the embodiments of this specification, and not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of this document.

FIG. 1 is a schematic diagram of an application scenario of a power distribution method for a four-wheel drive electric vehicle provided by an embodiment of the present specification. As shown in FIG. 1 , the scenario includes: a vehicle controller located on the vehicle and a vehicle controller for receiving torque distributed by the vehicle controller. , and use the torque to drive at least two motors (motor 1, motor 2, . Among them, the loss power table records the corresponding loss power when each motor produces different torques obtained from the pre-test.

Specifically, during the operation of the vehicle, the vehicle controller obtains the required torque for the driver to operate the vehicle and the real-time rotational speed of each motor. The running state signal is analyzed to obtain the required torque for the driver to operate the vehicle, wherein: the operation signal may include: the operation signal generated by operating at least one of the accelerator pedal, the gear position, and the brake pedal; the running state signal of the vehicle may include: the vehicle At least one signal of driving speed and vehicle temperature; the vehicle controller obtains the loss power of the corresponding motor when it generates different torques at the real-time speed from the loss power table corresponding to each motor, and calculates the required torque according to the torque sum value. , from the obtained torque corresponding to each motor, arbitrarily select a torque to combine, and calculate the loss power and value corresponding to each torque combination; The torque distribution ratio in each motor, so that the loss power and value corresponding to the determined torque distribution ratio meet the preset requirements.

Wherein, the power loss when each motor generates different torques may be obtained by performing a bench test on the whole vehicle in advance and stored in the system of the vehicle, such as in the vehicle controller or other storage medium. For example, before the whole vehicle leaves the warehouse, the power loss of each motor when each motor generates different torques at different speeds can be obtained through a bench test, and a loss power table can be constructed and stored in the system of the vehicle.

Further, the power loss when the motor generates torque may include: the motor is in a working state and the output power loss when the output torque is generated;

Correspondingly, according to the torque and the value of the required torque, from the obtained torque corresponding to each motor, arbitrarily select a torque to combine, and calculate the loss power and value corresponding to each torque combination. The processing can be specifically: according to the torque and The value is the required torque. From the obtained output torques corresponding to each motor, select an output torque to combine, and calculate the output loss power and value corresponding to each torque combination.

Alternatively, the power loss when the motor generates torque may include: the motor is in a working state, and the output loss power when the output torque is generated; and, the motor is in a non-working state, and the drag power when the drag torque is generated;

Correspondingly, according to the torque value and the required torque, from the obtained torques corresponding to each motor, select a torque to combine, and calculate the loss power and value corresponding to each torque combination. The torque sum value is the required torque. From the obtained output torque and drag torque corresponding to each motor, select an output torque or drag torque to combine, and calculate the loss power and value corresponding to each torque combination.

Further, the torque distribution ratio of the required torque in the at least two motors is determined according to the loss power sum value corresponding to each torque combination, so that the loss power sum value corresponding to the determined torque distribution ratio meets the preset requirement. When , a torque combination that satisfies the preset requirement may be selected from all the torque combinations, and the torque distribution ratio corresponding to the torque combination is determined as the torque distribution ratio of the required torque in the at least two motors.

Further, in the process of executing the above-mentioned method for power distribution of four-wheel-drive electric vehicles, if the loss power of the corresponding motor when different torques are generated at the real-time rotation speed is obtained from the loss power table corresponding to each motor, all the torque combinations formed are obtained. If the preset requirements cannot be met, after obtaining the loss power of the corresponding motor when the corresponding motor generates different torques at the real-time speed from the loss power table corresponding to each motor, it is also possible to perform: for the obtained torque corresponding to each motor and power loss, calculated by linear interpolation to obtain the corresponding interpolated torque and interpolated power loss; then, according to the torque and value of the required torque, the corresponding torque obtained from each motor, and the interpolated torque obtained based on these torques Among them, arbitrarily select a torque for combination, and calculate the loss power and value corresponding to each torque combination, so as to finally form a torque combination that meets the preset requirements.

Further, the above-mentioned preset requirements may include: the power loss sum value corresponding to the determined torque distribution ratio is smaller than a preset threshold value, or is the smallest among the loss power sum values corresponding to all torque distribution ratios.

The technical solutions of the present specification are further described below through a plurality of embodiments.

Example 1

Based on the above application scenario architecture, FIG. 2 is a schematic flow chart 1 of a method for power distribution of a four-wheel-drive electric vehicle provided by an embodiment of this specification. The method in FIG. 2 can be executed by the vehicle controller in FIG. 1 , and the four-wheel-drive electric vehicle There are at least two motors installed on it, as shown in Figure 2, the method includes the following steps:

S102 , during the running of the vehicle, obtain the required torque of the driver to operate the vehicle and the real-time rotational speed of the motor.

Among them, the required torque of the driver to operate the vehicle reflects the driver's driving intention to the vehicle, which can be obtained by analyzing the driver's operation behavior of the vehicle and the operating state of the vehicle itself.

For example, during the operation of the vehicle, the operation signal of the driver operating the vehicle and the operating state signal of the vehicle are analyzed to obtain the required torque for the driver to operate the vehicle.

Wherein, the operation signal may include: an operation signal generated by operating at least one of an accelerator pedal, a gear position, and a brake pedal; the running state signal of the vehicle may include at least one signal of the vehicle's running speed and the vehicle temperature.

Usually, during the operation of the vehicle, the real-time rotational speed of each motor on the same vehicle is the same, and the magnitude of the rotational speed is consistent with the rotational speed of the wheel. Therefore, the real-time rotational speed of the motor can be obtained by monitoring the real-time rotational speed of the vehicle wheels.

S104 , from the loss power table corresponding to each motor, obtain the loss power when the corresponding motor generates different torques at the real-time rotational speed.

Wherein, the power loss when each motor generates different torques may be obtained by performing a bench test on the whole vehicle in advance and stored in the system of the vehicle, such as in the vehicle controller or other storage medium. For example, before the whole vehicle leaves the warehouse, the power loss of each motor when each motor generates different torques at different speeds can be obtained through a bench test, and a loss power table can be constructed and stored in the system of the vehicle.

In a specific embodiment, in order to conveniently query the power loss of each motor on the vehicle when generating different torques, the loss power of each motor when generating different torques at different speeds can be obtained in advance, and a loss power table corresponding to the corresponding motor can be constructed. The power loss table records the power loss when each motor generates different torques at different speeds in discrete values.

Based on this, during vehicle operation, after obtaining the real-time rotational speed of each motor on the vehicle, the loss power of each motor when generating different torques at the real-time rotational speed can be obtained by querying the loss power table corresponding to each motor.

S106, according to the torque sum value as the required torque, from the obtained torque corresponding to each motor, arbitrarily select a torque to combine, and calculate the loss power and value corresponding to each torque combination.

After determining the power loss of each motor when generating different torques at the real-time speed, a torque can be selected from the torques corresponding to each motor to be combined, and the sum of the torques included in the combination is the above-mentioned requirement. torque. According to this combination, a plurality of such torque combinations can be constructed, and each torque combination includes and only includes one torque corresponding to each motor, and the sum of these torques is the above-mentioned demand torque. The loss power of each motor in each combination when generating the corresponding torque is added to obtain the corresponding loss power sum value of each combination.

S108: Determine the torque distribution ratio of the required torque among the at least two motors according to the loss power sum value corresponding to each torque combination, so that the loss power sum value corresponding to the determined torque distribution ratio meets a preset requirement.

Based on the loss power and value corresponding to each torque combination, the distribution of the corresponding loss power and value when the required torque is distributed in the above at least two motors with various torque distribution ratios can be analyzed, so that it can be determined. The torque distribution ratio corresponding to the power loss and value that meet the preset requirements.

Wherein, the preset requirement may include: the power loss sum value corresponding to the determined torque distribution ratio is smaller than a preset threshold value, or is the smallest among the loss power sum values corresponding to all torque distribution ratios.

In normal operation, the vehicle controller generally uses a simple equal ratio or other preset empirical ratio to distribute the driver's required torque to at least two motors on the vehicle, but this torque distribution method does not take into account the various The difference of the power loss of the motor when generating different torques often leads to a higher value of the loss power and the resulting loss, which makes the motor system less efficient.

In contrast, the power distribution method of the four-wheel drive electric vehicle shown in this embodiment uses the pre-obtained power loss when each motor generates different torques, and the pre-set conditions and requirements of the loss power and value, and the entire vehicle is controlled. The controller can quickly calculate the torque distribution ratio of the required torque among the motors according to the loss power and the value that meets the preset requirements, so that each motor can drive the vehicle when it receives the torque issued by the vehicle controller according to the torque distribution ratio. , the resulting loss power and value meet the above preset requirements, so as to achieve targeted adjustment of the efficiency of the motor system.

In the power distribution method for a four-wheel drive electric vehicle provided by the embodiments of the present specification, the four-wheel drive electric vehicle is installed with at least two motors, and during the operation of the vehicle, the required torque of the driver to operate the vehicle and the real-time rotational speed of the motors are obtained; From the loss power table corresponding to each motor, obtain the loss power of the corresponding motor when different torques are generated at the real-time speed; according to the torque value and the required torque, from the obtained torque corresponding to each motor, select any torque for combination. , and calculate the loss power and value corresponding to each torque combination; according to the loss power and value corresponding to each torque combination, determine the torque distribution ratio of the required torque in at least two motors, so that the determined torque distribution ratio corresponds to The loss power and value meet the preset requirements, so as to realize the reasonable distribution of the power of the whole vehicle, improve the efficiency of the motor system of the four-wheel drive electric vehicle, and reduce the adverse impact on energy consumption and battery life.

Embodiment 2

On the basis of the first embodiment, this embodiment expands and supplements the power distribution method for the four-wheel drive electric vehicle shown in FIG. 2 .

In a specific embodiment, the power loss when the motor generates torque may include: the motor is in a working state and the output power loss when the output torque is generated; accordingly, as shown in FIG. 3 , step S106 may include:

S106-2, according to the torque and the value of the required torque, from the obtained output torques corresponding to each motor, arbitrarily select an output torque to combine, and calculate the output loss power and value corresponding to each torque combination.

Among them, the output torque is defined as the torque actively output by the motor in the working state. According to the direction of the output torque of the motor, the output torque can be divided into positive and negative output torque; the process of the motor outputting the specified torque in the working state is accompanied by If the power is lost, this part of the power loss is called output power loss in this embodiment. Tables 1 and 2 correspond to the output power loss tables of the front and rear motors of the vehicle, respectively.

Table 1 Front motor output power loss table

Table 2. After the motor output power loss table

When the power loss of each motor when generating different torques is obtained in advance, each motor can be placed in a working state to obtain the output power loss when each motor generates different output torques at different speeds.

Correspondingly, when implementing this step, according to the torque value and the required torque value, from the torque generated by each motor at the real-time speed obtained from the loss power table, arbitrarily select an output torque to combine, and calculate each combination. Corresponding loss power and value. The loss power sum value is actually the sum value of the output loss power corresponding to each combination.

In another specific embodiment, the power loss when the motor generates torque may include: the motor is in a working state, and the output loss power when the output torque is generated; and the motor is in a non-working state, and the drag power when the drag torque is generated ; Correspondingly, as shown in Figure 4, step S106 may include:

S106-4, according to the torque value and the required torque, from the obtained output torque and drag torque corresponding to each motor, select any output torque or drag torque to combine, and calculate the loss power corresponding to each torque combination and value.

Among them, the definitions of output torque and output loss power refer to the above content; drag torque is defined as the torque passively generated by the motor in the non-working state. The overcome torque, that is, the additional power that the other electric machines of the vehicle need to generate to overcome this part of the torque, and this power is regarded as a power loss for the other electric machines as a whole. In this embodiment, the power when the drag torque is generated is called drag power, and the drag power can be directly regarded as a kind of loss power. Since the drag torque is the torque that the vehicle needs to overcome to achieve normal operation, it can be equivalent to the negative output torque in terms of the positive and negative nature of the torque. Tables 3 and 4 correspond to the drag power loss tables of the front and rear motors of the vehicle, respectively.

Table 3 Front motor drag power table

Speed r/min	0	50	80	100	120	150	180	200	230	250	280	300	350	400	1350
Drag power kW	0.00	0.02	0.04	0.05	0.06	0.08	0.10	0.12	0.14	0.16	0.18	0.20	0.24	0.29	2.40
Drag torque Nm	4.7	4.7	4.7	4.9	5.1	5.3	5.5	5.7	5.9	6.0	6.2	6.4	6.7	7.0	17.0

Table 4 Rear motor drag power table

When the loss power of each motor when generating different torques is obtained in advance, each motor can be placed in a working state to obtain the output power loss when each motor generates different output torques at different speeds; In the working state, to obtain the drag power when each motor generates drag torque at different speeds.

Correspondingly, in the implementation of this step, according to the torque value and the required torque value, one torque (output torque or drag torque) can be arbitrarily selected from the torque generated by each motor at the real-time speed obtained from the loss power table. combination, and calculate the corresponding loss power and value for each combination.

For example, when only the output torque is included in the combination, the sum of the lost power is actually the sum of the corresponding output loss power of each combination; when the combination includes both the output torque and the drag torque, the sum of the lost power is The actual sum of output loss power and drag power corresponding to each combination.

Further, as shown in FIG. 5 , the above step S108 may include the following steps:

S108-2, select a torque combination that meets the preset requirement from all the torque combinations, and determine the torque distribution ratio corresponding to the torque combination as the torque distribution ratio of the required torque among the at least two motors.

For example, after obtaining multiple combinations formed according to the torque and the required torque, the loss power and value corresponding to each combination can be screened according to the preset requirements, so as to determine from these combinations that the loss power and value meet the preset requirements. A required combination is set, and then the torque ratio between the motors corresponding to any one of the determined combinations is selected as the torque distribution ratio of the required torque among the at least two motors.

In addition, in the process of performing step S108-2, if the loss power of the corresponding motor when generating different torques at the real-time rotational speed is obtained based on the loss power table corresponding to each motor, all the formed torque combinations cannot meet the preset requirements. requirements, the method steps shown in FIG. 6 can be performed to remedy this problem, that is, after step S104, the following steps are performed:

S105, the obtained torque and power loss corresponding to each motor are calculated by using a linear interpolation method, so as to obtain the corresponding interpolation torque and power loss.

Wherein, in the above S105, linear interpolation can be performed according to the following formula according to the loss power corresponding to the known rotational speed and torque: (yy ₀ )/(xx ₀ )=(y ₁ -y ₀ )/(x ₁ -x ₀ ) . In this formula, x refers to the interpolation torque, y is the interpolation loss power corresponding to the interpolation torque, x _{0 and} x ₁ are known torques, y ₀ is the power loss corresponding to x ₀ , and y ₁ is the corresponding power to x ₁ , namely (x ₀ , y ₀ ) is a set of known torque and corresponding power loss, (x ₁ , y ₁ ) is another set of known torque and corresponding power loss, y is unknown Interpolation loss power.

In practical applications, since the loss power tables above all store the power loss when each motor generates different torques at different speeds in the form of discrete values, it is impossible to exhaustively enumerate all the data. Therefore, in the process of querying the power loss table to obtain the power loss when each motor generates torque, the discrete values recorded in the power loss table can be calculated by using the line interpolation method to obtain the power loss when the motor generates any torque at any speed. Loss of power to meet all data acquisition needs.

Correspondingly, the above step S106 may specifically include:

S106-6, according to the torque value and the required torque, from the obtained torque corresponding to each motor and the interpolated torque obtained based on these torques, arbitrarily select a torque to combine, and calculate the loss power corresponding to each torque combination and value.

The obtained torque specifically refers to the torque generated by each motor at the real-time speed obtained from the loss power table corresponding to each motor, and the interpolation torque is based on the torque meridian interpolation method directly obtained from the loss power table. Calculated torque. When the torque is combined, the two torques can be combined as the torque corresponding to the motor.

Using the interpolation torque calculated by the warp interpolation method to participate in the torque combination can make up for the defect that the torque combination that meets the preset requirements cannot be formed due to the limited amount of data recorded in the loss power meter.

After step S106-6, step S108-2 can be continued.

Based on the power distribution method of the four-wheel-drive electric vehicle shown in the above embodiment, taking two motors (front and rear motors) installed on the four-wheel-drive electric vehicle as an example, it is exemplified to seek the minimum total power loss in practical application scenarios. The method of torque distribution ratio:

For example, the demand torque requested by the driver is T _d , the real-time motor speed is _n , the front motor torque (output torque, drag torque) is T _f , the rear motor torque (output torque, drag torque) is Tr , the front motor is The power loss (output loss power, drag power) is P _f , the rear motor power loss (output loss power, drag power) is _{Pr , and the total power loss is P t .} where T _d =T _f + _Tr , P _t =P _f + _Pr . By calculating the total power loss _Pt for all front and rear torque distribution possibilities, and finding the distribution that minimizes _Pt .

Example 1: When T _d = 200, n = 200, the power losses of the front and rear motors under different torque distribution modes are calculated by linear interpolation, and the total power loss is obtained by summing the table as follows:

Table 4 Total Power Loss Table

It can be seen from the table that under this condition, when the rear motor does not work (that is, it enters the dragging condition), the total power loss is the smallest when the front motor outputs 206Nm.

Example 2: When T _d = 2000, n = 300, the power losses of the front and rear motors under different torque distribution modes are calculated by linear interpolation, and the total power loss is obtained by summing the table as follows:

Table 5 Total Power Loss Table

It can be seen from the table that the total power loss is the smallest when the front and rear motors output 1000Nm respectively under this working condition. The torque distribution table of the front and rear motors with the minimum total power loss obtained by the above method is as follows:

Table 6-1 Torque distribution table of front motor with minimum total power loss

Table 6-2 Rear motor torque distribution table with minimum total power loss

Finally, the front and rear motor controllers respectively control the torque output of the front and rear motors according to the torque allocated in the above table according to the VCU, so as to optimize the power distribution of the whole vehicle.

In the power distribution method for a four-wheel drive electric vehicle provided by the embodiments of the present specification, the four-wheel drive electric vehicle is installed with at least two motors, and during the operation of the vehicle, the required torque of the driver to operate the vehicle and the real-time rotational speed of the motors are obtained; From the loss power table corresponding to each motor, obtain the loss power of the corresponding motor when different torques are generated at the real-time speed; according to the torque value and the required torque, from the obtained torque corresponding to each motor, select any torque for combination. , and calculate the loss power and value corresponding to each torque combination; according to the loss power and value corresponding to each torque combination, determine the torque distribution ratio of the required torque in at least two motors, so that the determined torque distribution ratio corresponds to The loss power and value meet the preset requirements, so as to realize the reasonable distribution of the power of the whole vehicle, improve the efficiency of the motor system of the four-wheel drive electric vehicle, and reduce the adverse impact on energy consumption and battery life.

Embodiment 3

Corresponding to the power distribution method of the four-wheel drive electric vehicle described above in FIGS. 2 to 6 , and based on the same technical concept, the embodiment of the present specification further provides a power distribution device for the four-wheel drive electric vehicle. FIG. 7 is a schematic diagram of the module composition of the four-wheel drive electric vehicle power distribution device provided in the embodiment of the present specification. At least two motors are installed on the four-wheel drive electric vehicle, and the device is used to execute the four-wheel drive electric vehicle described in FIGS. 2 to 6 . The vehicle power distribution method, as shown in Figure 7, the device includes:

The data acquisition module 201 acquires the required torque of the driver to operate the vehicle and the real-time rotational speed of the motor during the operation of the vehicle;

The torque acquisition module 202 acquires, from the loss power table corresponding to each motor, the power loss when the corresponding motor generates different torques at the real-time rotational speed;

The combination calculation module 203, according to the torque value and the required torque value, arbitrarily selects a torque from the obtained torque corresponding to each motor for combination, and calculates the loss power and value corresponding to each torque combination;

The torque distribution module 204 determines the torque distribution ratio of the required torque in the at least two motors according to the loss power and value corresponding to each torque combination, so that the loss power sum value corresponding to the determined torque distribution ratio meets the preset value Require.

Optionally, the power loss when the motor generates torque may include: the motor is in a working state and the output power loss when the output torque is generated;

Correspondingly, the combination calculation module 203 arbitrarily selects an output torque for combination from the obtained output torques corresponding to each motor according to the torque sum value and calculates the output loss power sum value corresponding to each torque combination.

Optionally, the power loss when the motor generates torque may include: the motor is in a working state, and the output loss power when the output torque is generated; and, the motor is in a non-working state, and the drag power when the drag torque is generated;

Correspondingly, the combination calculation module 203 arbitrarily selects an output torque or drag torque from the obtained output torque and the drag torque corresponding to each of the motors according to the torque value and the value of the demand torque. combinations, and calculate the lost power and values for each torque combination.

Optionally, the torque distribution module 204 selects a torque combination that meets a preset requirement from all the torque combinations, and determines the torque distribution ratio corresponding to the torque combination as the torque distribution of the required torque among the at least two motors. Proportion.

Optionally, the above-mentioned four-wheel drive electric vehicle power distribution device may further include:

The interpolation calculation module, if all the torque combinations formed cannot meet the preset requirements based on the loss power of the corresponding motors when they generate different torques at the real-time rotation speed based on the loss power table corresponding to each motor, then in the From the loss power table corresponding to each motor, after obtaining the loss power when the corresponding motor generates different torques at the real-time speed, the obtained torque and loss power of each motor are calculated by linear interpolation to obtain the corresponding torque and loss power of each motor. Interpolation torque and interpolation loss power;

Correspondingly, the combination calculation module 203 arbitrarily selects a torque for combination from the obtained torque corresponding to each motor and the interpolated torque obtained based on these torques according to the torque value and the required torque value, and calculates the corresponding torque of each torque combination. power loss and value to form a torque combination that meets the preset requirements. Optionally, the data acquisition module 201, during the operation of the vehicle, analyzes the operation signal of the driver operating the vehicle and the operating state signal of the vehicle to obtain the required torque for the driver to operate the vehicle.

Optionally, the above-mentioned operation signal may include: an operation signal generated by operating at least one of an accelerator pedal, a gear position, and a brake pedal; the above-mentioned vehicle operating state signal may include: at least one signal of a vehicle's running speed and a vehicle temperature .

Optionally, the above-mentioned four-wheel drive electric vehicle power distribution device may further include:

The data table builds the module, obtains the power loss of each motor when generating different torques at different speeds, and constructs the loss power table corresponding to the corresponding motor.

Optionally, the above-mentioned preset requirement may include: the power loss sum value corresponding to the determined torque distribution ratio is smaller than a preset threshold value, or is the smallest among the loss power sum values corresponding to all torque distribution ratios.

In the four-wheel-drive electric vehicle power distribution device provided by the embodiments of this specification, at least two motors are installed on the four-wheel-drive electric vehicle, by obtaining the required torque of the driver to operate the vehicle and the real-time rotational speed of the motors during the running of the vehicle; From the loss power table corresponding to each motor, obtain the loss power of the corresponding motor when different torques are generated at the real-time speed; according to the torque value and the required torque, from the obtained torque corresponding to each motor, select any torque for combination. , and calculate the loss power and value corresponding to each torque combination; according to the loss power and value corresponding to each torque combination, determine the torque distribution ratio of the required torque in at least two motors, so that the determined torque distribution ratio corresponds to The loss power and value meet the preset requirements, so as to realize the reasonable distribution of the power of the whole vehicle, improve the efficiency of the motor system of the four-wheel drive electric vehicle, and reduce the adverse impact on energy consumption and battery life.

It should be noted that the embodiment of the four-wheel drive electric vehicle power distribution device in this specification and the embodiment of the four-wheel drive electric vehicle power distribution method in this specification are based on the same inventive concept, so the specific implementation of this embodiment can refer to the above-mentioned corresponding The implementation of the four-wheel drive electric vehicle power distribution method is not repeated.

The foregoing describes specific embodiments of the present specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that in the embodiments and still achieve desirable results. Additionally, the processes depicted in the figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

In the 1930s, improvements in a technology could be clearly distinguished as improvements in hardware (eg, improvements in circuit structures such as diodes, transistors, switches, etc.) or improvements in software (improvements in method flow). However, with the development of technology, the improvement of many methods and processes today can be regarded as a direct improvement of the hardware circuit structure. Designers almost get the corresponding hardware circuit structure by programming the improved method flow into the hardware circuit. Therefore, it cannot be said that the improvement of a method flow cannot be realized by hardware entity modules. For example, a Programmable Logic Device (PLD) (such as a Field Programmable Gate Array (FPGA)) is an integrated circuit whose logic function is determined by user programming of the device. It is programmed by the designer to "integrate" a digital system on a PLD without having to ask the chip manufacturer to design and manufacture a dedicated integrated circuit chip. Moreover, today, instead of making integrated circuit chips by hand, this kind of programming is also mostly implemented using "logic compiler" software, which is similar to the software compiler used in program development and writing, and needs to be compiled before compiling. The original code also has to be written in a specific programming language, which is called Hardware Description Language (HDL), and there is not only one HDL, but many kinds, such as ABEL (Advanced Boolean Expression Language) , AHDL (Altera Hardware Description Language), Confluence, CUPL (Cornell University Programming Language), HDCal, JHDL (Java Hardware Description Language), Lava, Lola, MyHDL, PALASM, RHDL (Ruby Hardware Description Language), etc., currently the most commonly used The ones are VHDL (Very-High-Speed Integrated Circuit Hardware Description Language) and Verilog. It should also be clear to those skilled in the art that a hardware circuit for implementing the logic method process can be easily obtained by simply programming the method process in the above-mentioned several hardware description languages and programming it into the integrated circuit.

The controller may be implemented in any suitable manner, for example, the controller may take the form of eg a microprocessor or processor and a computer readable medium storing computer readable program code (eg software or firmware) executable by the (micro)processor , logic gates, switches, application specific integrated circuits (ASICs), programmable logic controllers and embedded microcontrollers, examples of controllers include but are not limited to the following microcontrollers: ARC625D, Atmel AT91SAM, Microchip PIC18F26K20 and Silicon Labs C8051F320, the memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art also know that, in addition to implementing the controller in the form of pure computer-readable program code, the controller can be implemented as logic gates, switches, application-specific integrated circuits, programmable logic controllers and embedded devices by logically programming the method steps. The same function can be realized in the form of a microcontroller, etc. Therefore, such a controller can be regarded as a hardware component, and the devices included therein for realizing various functions can also be regarded as a structure within the hardware component. Or even, the means for implementing various functions can be regarded as both a software module implementing a method and a structure within a hardware component.

The systems, devices, modules or units described in the above embodiments may be specifically implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or A combination of any of these devices.

For the convenience of description, when describing the above device, the functions are divided into various units and described respectively. Of course, when implementing the embodiments of the present specification, the functions of each unit may be implemented in one or more software and/or hardware.

As will be appreciated by one skilled in the art, one or more embodiments of this specification may be provided as a method, system or computer program product. Accordingly, one or more embodiments of this specification may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present specification may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The specification is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the specification. It will be understood that each flow and/or block in the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flow of a flowchart and/or a block or blocks of a block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions The apparatus implements the functions specified in the flow or flow of the flowcharts and/or the block or blocks of the block diagrams.

These computer program instructions can also be loaded on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process such that The instructions provide steps for implementing the functions specified in the flow or blocks of the flowcharts and/or the block or blocks of the block diagrams.

In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

Memory may include forms of non-persistent memory, random access memory (RAM) and/or non-volatile memory in computer readable media, such as read only memory (ROM) or flash memory (flash RAM). Memory is an example of a computer-readable medium.

Computer-readable media includes both persistent and non-permanent, removable and non-removable media, and storage of information may be implemented by any method or technology. Information may be computer readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read only memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), Flash Memory or other memory technology, Compact Disc Read Only Memory (CD-ROM), Digital Versatile Disc (DVD) or other optical storage, Magnetic tape cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media, such as modulated data signals and carrier waves.

It should also be noted that the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device comprising a series of elements includes not only those elements, but also Other elements not expressly listed, or which are inherent to such a process, method, article of manufacture, or apparatus are also included. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article of manufacture, or device that includes the element.

One or more embodiments of this specification may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. One or more embodiments of this specification may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including storage devices.

Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, as for the system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and for related parts, please refer to the partial descriptions of the method embodiments.

The above descriptions are only examples of this document, and are not intended to limit this document. Various modifications and variations of this document are possible for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this document shall be included within the scope of the claims of this document.

Claims (18)

1. A power distribution method for a four-wheel drive electric vehicle, wherein at least two motors are installed on the four-wheel drive electric vehicle, and the method includes:

   During the operation of the vehicle, obtain the required torque of the driver to operate the vehicle and the real-time rotational speed of the motor;

   From the loss power table corresponding to each of the motors, obtain the loss power when the corresponding motors generate different torques at the real-time rotational speed;

   According to the torque and the value of the required torque, from the obtained torque corresponding to each of the motors, arbitrarily select a torque to combine, and calculate the loss power and value corresponding to each torque combination;

   According to the loss power sum value corresponding to each torque combination, the torque distribution ratio of the required torque in the at least two electric machines is determined, so that the loss power sum value corresponding to the determined torque distribution ratio meets the preset requirement.
2. The method according to claim 1, wherein the loss of power when the motor generates torque comprises: the motor is in a working state and the output loss of power when the output torque is generated;

   According to the torque sum value, according to the demand torque, from the obtained torque corresponding to each of the motors, arbitrarily select a torque for combination, and calculate the loss power and value corresponding to each torque combination, including:

   According to the torque sum value of the demand torque, an output torque is arbitrarily selected from the obtained output torques corresponding to each of the motors to be combined, and the output loss power sum value corresponding to each torque combination is calculated.
3. The method according to claim 1, wherein the loss of power when the motor generates torque comprises: the motor is in a working state and the output power is lost when the output torque is generated; and, when the motor is in a non-working state, the dragging torque is generated power;

   According to the torque sum value, according to the demand torque, from the obtained torque corresponding to each of the motors, arbitrarily select a torque for combination, and calculate the loss power and value corresponding to each torque combination, including:

   According to the torque value and the required torque, from the obtained output torque and the drag torque corresponding to each motor, select an output torque or drag torque to combine, and calculate each torque combination Corresponding loss power and value.
4. 2. The method of claim 1, wherein a torque distribution ratio of the demanded torque among the at least two electric machines is determined according to the power loss sum value corresponding to each torque combination, so that the determined torque distribution The loss power and value corresponding to the ratio meet the preset requirements including:

   One torque combination that meets the preset requirement is selected from all the torque combinations, and the torque distribution ratio corresponding to the torque combination is determined as the torque distribution ratio of the required torque in the at least two electric machines.
5. The method of claim 4, wherein the method further comprises:

   If all the torque combinations formed cannot meet the preset requirements based on obtaining the power loss of the corresponding motors when they generate different torques at the real-time rotation speed from the loss power table corresponding to each of the motors, then in the From the loss power table corresponding to each of the motors, after obtaining the loss power of the corresponding motors when they generate different torques at the real-time rotational speed, the method further includes:

   Calculate the obtained torque and power loss corresponding to each of the motors by using a linear interpolation method to obtain the corresponding interpolation torque and power loss;

   According to the torque value and the required torque, from the obtained torque corresponding to each of the motors and the interpolated torque obtained based on these torques, arbitrarily select a torque to combine, and calculate the loss power and the corresponding torque combination. value.
6. The method of claim 1 , wherein, during operation of the vehicle, obtaining the torque demanded by the driver to operate the vehicle comprises:

   During the operation of the vehicle, the operation signal of the driver operating the vehicle and the operating state signal of the vehicle are analyzed to obtain the required torque for the driver to operate the vehicle.
7. The method according to claim 6, wherein the operation signal comprises: an operation signal generated by operating at least one of an accelerator pedal, a gear position, and a brake pedal; the running state signal of the vehicle comprises: a driving speed of the vehicle, a At least one signal of vehicle temperature.
8. The method of claim 1, wherein the method further comprises:

   Obtain the power loss of each of the motors when they generate different torques at different speeds, and construct the loss power table corresponding to the corresponding motors.
9. The method according to any one of claims 1-8, wherein the preset requirement comprises: the sum of the lost power corresponding to the determined torque distribution ratio is smaller than a preset threshold, or the lost power corresponding to all torque distribution ratios and the smallest value.
10. A power distribution device for a four-wheel drive electric vehicle, wherein at least two motors are installed on the four-wheel drive electric vehicle, and the device comprises:

    The data acquisition module, during the operation of the vehicle, acquires the required torque of the driver to operate the vehicle and the real-time rotational speed of the motor;

    The torque acquisition module acquires, from the loss power table corresponding to each of the motors, the loss power of the corresponding motor when different torques are generated at the real-time rotational speed;

    The combination calculation module, according to the torque and the value of the required torque, arbitrarily selects a torque to combine from the obtained torque corresponding to each of the motors, and calculates the loss power and value corresponding to each torque combination;

    The torque distribution module determines the torque distribution ratio of the demanded torque in the at least two motors according to the loss power and value corresponding to each torque combination, so that the loss power and value corresponding to the determined torque distribution ratio meet the predetermined requirements. set requirements.
11. The power distribution device for a four-wheel drive electric vehicle according to claim 10, wherein the loss of power when the motor generates torque comprises: the output power loss when the motor is in a working state and the output torque is generated;

    The combination calculation module, according to the torque and the value of the required torque, arbitrarily selects an output torque from the obtained output torques corresponding to each of the motors for combination, and calculates the output loss corresponding to each torque combination power and value.
12. The power distribution device for a four-wheel drive electric vehicle according to claim 10, wherein the loss of power when the motor generates torque comprises: the motor is in a working state, and the output power is lost when the output torque is generated; Drag power at drag torque;

    The combination calculation module, according to the torque and the value of the required torque, arbitrarily selects an output torque or a drag torque from the obtained output torque and the drag torque corresponding to each of the motors to combine, And calculate the lost power and value corresponding to each torque combination.
13. The four-wheel drive electric vehicle power distribution device according to claim 10, wherein the torque distribution module selects a torque combination that meets the preset requirements from all the torque combinations, and determines the torque distribution ratio corresponding to the torque combination. A torque distribution ratio of the required torque among the at least two electric machines is provided.
14. The four-wheel drive electric vehicle power distribution device according to claim 10, wherein the four-wheel drive electric vehicle power distribution device further comprises:

    The interpolation calculation module, if all the torque combinations formed cannot meet the preset requirements based on the loss power of the corresponding motors when they generate different torques at the real-time rotation speed based on the loss power table corresponding to each motor, then in the From the loss power table corresponding to each motor, after obtaining the loss power when the corresponding motor generates different torques at the real-time speed, the obtained torque and loss power of each motor are calculated by linear interpolation to obtain the corresponding torque and loss power of each motor. Interpolation torque and interpolation loss power;

    The combination calculation module, according to the torque and the value of the required torque, selects a torque arbitrarily for combination from the obtained torque corresponding to each motor and the interpolation torque obtained based on these torques, and calculates the loss corresponding to each torque combination power and value.
15. The four-wheel drive electric vehicle power distribution device according to claim 10, wherein the data acquisition module analyzes the operation signal of the driver operating the vehicle and the operating state signal of the vehicle during the operation of the vehicle, and obtains the operation signal of the driver operating the vehicle. required torque.
16. The power distribution device for a four-wheel drive electric vehicle according to claim 15, wherein the operation signal comprises: an operation signal generated by operating at least one of an accelerator pedal, a gear position, and a brake pedal; the running state signal of the vehicle comprises: : At least one signal of vehicle speed and vehicle temperature.
17. The four-wheel drive electric vehicle power distribution device according to claim 10, wherein the four-wheel drive electric vehicle power distribution device further comprises: a data table building module to obtain the power loss when each motor generates different torques at different speeds, And construct the loss power table corresponding to the corresponding motor.
18. The power distribution device for a four-wheel drive electric vehicle according to any one of claims 10-17, wherein the preset requirement includes: the sum of the lost power corresponding to the determined torque distribution ratio is less than a preset threshold, or when all torques The loss power and the value corresponding to the distribution ratio are the smallest.

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