CN114347800A

CN114347800A - Distributed four-wheel drive pure range extending system and control method thereof

Info

Publication number: CN114347800A
Application number: CN202210043917.4A
Authority: CN
Inventors: 张春才; 张明宇; 张显波; 赵东峰; 张行; 杨振
Original assignee: FAW Group Corp
Current assignee: FAW Group Corp
Priority date: 2022-01-14
Filing date: 2022-01-14
Publication date: 2022-04-15
Anticipated expiration: 2042-01-14
Also published as: CN114347800B

Abstract

The invention relates to the technical field of vehicles and discloses a distributed four-wheel drive pure range extending system and a control method thereof. The distributed four-wheel-drive pure range extending system comprises: the driving assembly comprises a motor control module and four in-wheel motors, wherein when at least one wheel slips, the motor control module is configured to control other in-wheel motors to drive the wheel to rotate; the range extending assembly comprises a power generation control module, an engine and a generator which is electrically connected with the power battery through a high-voltage wire; the steering assembly comprises a steering control module and four steering machines, and each steering machine corresponds to one wheel. The invention discloses a distributed four-wheel drive pure range extending system and a control method thereof, which solve the problems that the wheels of the vehicle are not easy to get rid of the difficulty, cooling equipment with strong heat dissipation capacity is required to be equipped and the small rotating radius cannot be realized in the conventional vehicle.

Description

Distributed four-wheel drive pure range extending system and control method thereof

Technical Field

The invention relates to the technical field of vehicles, in particular to a distributed four-wheel drive pure range extending system and a control method thereof.

Background

The synchronous action of the hub motors of two front wheels and the synchronous action of the hub motors of two rear wheels of the existing vehicle are not beneficial to the escape of a certain wheel of the vehicle when the certain wheel of the vehicle slips, and meanwhile, the heat loss of the hub motors is increased due to the low-voltage electric connection between the existing hub motors and the corresponding control modules, so that cooling equipment with strong heat dissipation capacity needs to be equipped. In addition, when the vehicle turns, the two front wheels synchronously act, and the two rear wheels synchronously act, so that the whole vehicle with small turning radius cannot be turned.

Disclosure of Invention

Based on the above, the invention aims to provide a distributed four-wheel drive pure range extending system and a control method thereof, and solves the problems that the existing vehicle is not easy to get rid of difficulties when the wheels of the vehicle slip, cooling equipment with strong heat dissipation capacity must be equipped, and small rotation radius cannot be realized.

In order to achieve the purpose, the invention adopts the following technical scheme:

a distributed four-wheel drive pure range extending system, comprising: the driving assembly comprises a motor control module and four hub motors, the motor control module comprises a front double-motor controller and a rear double-motor controller, the front double-motor controller is respectively and electrically connected with the two hub motors corresponding to the two front wheels through high-voltage wires, the rear double-motor controller is respectively and electrically connected with the two hub motors corresponding to the two rear wheels through high-voltage wires, and when at least one wheel slips, the motor control module is configured to control the other hub motors to drive the wheel to rotate; the battery assembly comprises a battery control module and power batteries, the battery control module is electrically connected with the power batteries, and the power batteries are electrically connected with the four motor control modules through high-voltage wires; the range extending assembly comprises a power generation control module, an engine and a generator electrically connected with the power battery through a high-voltage wire, wherein the power generation control module is electrically connected with the generator, the engine is in transmission connection with the generator, the generator is electrically connected with the hub motor, and when the electric quantity of the power battery is lower than a preset low electric quantity, the power generation control module is configured to control the generator or the hub motor to generate power and store electric energy to the power battery; the steering assembly comprises a steering control module and four steering machines, the four steering machines are electrically connected with the steering control module and the power battery, each steering machine corresponds to one wheel, and the steering control module is configured to calculate the steering torque and the steering angle of each steering machine and control the steering machines to steer; and the whole vehicle control module is electrically connected with the motor control module, the power battery control module, the power generation control module and the steering control module respectively.

As a preferred scheme of the distributed four-wheel drive pure range extending system, the distributed four-wheel drive pure range extending system further comprises a brake assembly, wherein the brake assembly comprises a brake control module and four brake motor assemblies, the brake control module is respectively electrically connected with the whole vehicle control module and the four brake motor assemblies, each brake motor assembly is arranged corresponding to one wheel, and the four brake motor assemblies are electrically connected with the power battery and the generator; when the vehicle accelerates or at least one appears in the process of passing through a wet road surface when the wheel skids, the whole vehicle control module passes through the motor control module reduces and skids the wheel corresponds to the output torque of the hub motor, or the whole vehicle control module passes through the brake control module controls and skids the wheel corresponds to the brake motor assembly outputs the braking force.

As a preferred scheme of the distributed four-wheel drive pure range extending system, the distributed four-wheel drive pure range extending system further includes an engine control module electrically connected to the vehicle control module, the engine control module is electrically connected to the engine, and the engine control module is configured to control the engine to be electrically connected to the generator when the electric quantity of the power battery is lower than a preset low electric quantity.

As a preferred scheme of the distributed four-wheel drive pure range extending system, the distributed four-wheel drive pure range extending system further comprises a direct current converter, the direct current converter is electrically connected with the whole vehicle control module, and the direct current converter, the motor control module, the battery control module, the power generation control module, the steering control module, the whole vehicle control module, the braking control module and the engine control module are integrated in a power domain controller.

As an optimal scheme of the distributed four-wheel drive pure range extending system, the steering control module comprises a steering master control module, a front steering control module and a rear steering control module, the steering master control module is respectively connected with the whole vehicle control module, the front steering control module and the rear steering control module, the front steering control module is respectively electrically connected with the steering machines corresponding to the two front wheels, and the rear steering control module is respectively electrically connected with the steering machines corresponding to the two rear wheels.

A control method suitable for the distributed four-wheel drive pure range extending system in any one of the above aspects, comprising the steps of:

s1, the whole vehicle control module calculates the required driving power and the required output torque of the vehicle;

s2, judging whether one of the preset high discharge power of the power battery is smaller than the required driving power and the electric quantity of the power battery reaches or is lower than a preset low electric quantity or not, if so, executing S3; if not, go to S4;

s3, judging whether the speed of the vehicle is zero or not, and if so, enabling the vehicle to enter an idle speed power generation mode; if not, the engine drives the generator to generate power, and S4 is executed;

s4, judging whether the vehicle enters an off-road mode or not, if so, executing S5; if not, go to S6;

s5, selecting one of an off-road single-drive mode, an off-road two-drive mode, an off-road three-drive mode and an off-road four-drive mode according to the slip state of the wheels, and executing S7;

s6, judging whether the vehicle selects a four-wheel drive mode, if so, enabling the vehicle to enter the four-wheel drive mode; if not, the vehicle enters a two-wheel drive mode, and S7 is executed;

and S7, the whole vehicle control module judges whether the current running state of the vehicle meets the driving requirement, and if not, the whole vehicle control module returns to S2.

As a preferred scheme of the control method of the distributed four-wheel drive pure range extending system, the off-road two-wheel drive mode comprises an off-road front-wheel drive mode, an off-road rear-wheel drive mode and an off-road oblique two-wheel drive mode, when two rear wheels both slip, the off-road front-wheel drive mode is executed in S5, and the motor control module controls the hub motors corresponding to the two front wheels to work; when both the front wheels slip, the off-road rear drive mode is executed in S5, and the motor control module controls the in-wheel motors corresponding to both the rear wheels to operate; when both of the wheels on the diagonal line of the vehicle slip, the diagonal two-drive mode is performed in S5, and the motor control module controls the in-wheel motors corresponding to the other two wheels on the diagonal line of the vehicle to operate.

As a preferable scheme of the control method of the distributed four-wheel drive pure range extending system, when three wheels slip, the off-road single drive mode is executed in S5, and the motor control module controls the operation of the remaining one of the hub motors corresponding to the wheels; when one of the wheels slips, the off-road three-drive mode is executed in S5, and the motor control module controls the operation of the remaining three in-wheel motors corresponding to the wheels; when all four of the wheels slip, the off-road four-wheel drive mode can be performed in S5, and the motor control module controls four of the in-wheel motors corresponding to the wheels to operate.

As a preferable scheme of the control method of the distributed four-wheel drive pure range extending system, the S2 includes the steps of:

s21, judging whether the preset high discharge power of the power battery 22 is smaller than the required driving power, if so, not starting the engine and executing S3; if not, go to S22;

s22, judging whether the electric quantity of the power battery reaches or is lower than a preset low electric quantity, if so, executing S3; if not, the engine is started and S4 is executed.

As a preferred scheme of a control method of a distributed four-wheel drive pure range-increasing system, the four-wheel drive mode comprises a range-increasing four-wheel drive mode and a pure electric four-wheel drive mode, the two-wheel drive mode comprises a pure electric two-wheel drive mode and a range-increasing two-wheel drive mode, the pure electric two-wheel drive mode comprises a pure electric front drive mode and a pure electric rear drive mode, the range-increasing two-wheel drive mode comprises a range-increasing front drive mode and a range-increasing rear drive mode, and when a vehicle passes through S4 and executes S6 from S2, the vehicle enters the pure electric four-wheel drive mode or the pure electric two-wheel drive mode; when the vehicle passes through S4 from S3 and executes S6, the vehicle enters the range-extended four-wheel drive mode or the range-extended two-wheel drive mode.

The invention has the beneficial effects that: the distributed four-wheel-drive pure range extending system disclosed by the invention has the advantages that each wheel is controlled by one hub motor, once one wheel slips, the motor control module can control the other hub motors to drive the wheels to rotate, so that the difficulty of the vehicle is favorably overcome, the motor control module is electrically connected with each hub motor by adopting high voltage, and compared with the existing low voltage electrical connection, the heat loss of the hub motors is reduced, so that the hub motors do not need to be provided with cooling equipment with stronger heat dissipation capacity, the investment cost of the cooling equipment is reduced, and each wheel is controlled by one steering gear, so that the steering of the vehicle is more flexible, and the steering with small rotating radius can be realized.

The control method of the distributed four-wheel drive pure range extending system can select the current running mode of the vehicle according to the electric quantity of the power battery, so that the electric quantity of the power battery is always maintained in a proper electric quantity range, and when at least one wheel of the vehicle slips, the vehicle can select one of an off-road single-wheel drive mode, an off-road two-wheel drive mode, an off-road three-wheel drive mode and an off-road four-wheel drive mode, so that the vehicle is out of the trouble.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

FIG. 1 is a block diagram of a distributed four-wheel drive pure range extension system provided by an embodiment of the present invention;

fig. 2 is a flowchart of a control method of a distributed four-wheel drive range-only system according to an embodiment of the present invention.

In the figure:

11. a hub motor; 12. a front dual-motor controller; 13. a rear dual-motor controller;

21. a battery control module; 22. a power battery;

31. a power generation control module; 32. an engine; 33. a generator;

41. a steering machine; 42. a steering master control module; 43. a front steering control module; 44. a rear steering control module;

51. a vehicle control module; 52. an engine control module; 53. a DC converter;

61. a brake control module; 62. braking the motor assembly;

100. and (7) wheels.

Detailed Description

In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection or a removable connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The embodiment provides a distributed four-wheel drive pure range extending system, which comprises a driving assembly, a battery assembly, a range extending assembly, a steering assembly and a whole vehicle control module 51, wherein the driving assembly comprises a motor control module and four in-wheel motors 11, the motor control module is respectively electrically connected with each in-wheel motor 11 through a high-voltage wire, each in-wheel motor 11 is respectively in transmission connection with one wheel 100, when at least one wheel 100 slips, the motor control module is configured to control other in-wheel motors 11 to drive the wheels 100 to rotate, the battery assembly comprises a battery control module 21 and a power battery 22, the battery control module 21 is electrically connected with the power battery 22, the power battery 22 is electrically connected with the four motor control modules through the high-voltage wires, the range extending assembly comprises a power generation control module 31, an engine 32 and a generator 33 electrically connected with the power battery 22 through the high-voltage wires, the power generation control module 31 is electrically connected with the power generator 33, the engine 32 is in transmission connection with the power generator 33, the power generator 33 is electrically connected with the in-wheel motor 11, when the electric quantity of the power battery 22 is lower than a preset low electric quantity, the power generation control module 31 is configured to control the power generator 33 or the in-wheel motor 11 to generate power and store electric energy to the power battery 22, the steering assembly comprises a steering control module and four steering machines 41, the four steering machines 41 are electrically connected with the steering control module and the power battery 22, each steering machine 41 corresponds to one wheel 100, the steering control module is configured to calculate the steering torque and the steering angle of each steering machine 41 and control the steering machines 41 to steer, and the whole vehicle control module 51 is electrically connected with the motor control module, the battery control module 21, the power generation control module 31 and the steering control module respectively.

The motor control module of this embodiment includes preceding two motor controller 12 and back two motor controller 13, and preceding two motor controller 12 is connected with two wheel hub motors 11 electricity that two front wheels correspond respectively, and back two motor controller 13 is connected with two wheel hub motors 11 electricity that two back wheels correspond respectively. That is, the front dual-motor controller 12 controls two in-wheel motors 11 corresponding to two front wheels so that each in-wheel motor 11 can drive one front wheel to rotate, respectively, and the rear dual-motor controller 13 controls two in-wheel motors 11 corresponding to two rear wheels so that each in-wheel motor 11 can drive one rear wheel to rotate, respectively.

It should be noted that when the four wheels 100 of the vehicle slightly slip, each in-wheel motor 11 drives one wheel 100 to rotate, so as to make the vehicle get out of the way.

The distributed four-wheel-drive pure range extending system provided by the embodiment is characterized in that each wheel 100 is controlled by one in-wheel motor 11, once one wheel 100 skids, the motor control module can control the rest in-wheel motors 11 to drive the wheel 100 to rotate, so that the vehicle is beneficial to getting rid of difficulties, the motor control module is electrically connected with each in-wheel motor 11 through high voltage, compared with the existing low voltage electric connection, the heat loss of the in-wheel motor 11 is reduced, therefore, the in-wheel motor 11 is not required to be provided with cooling equipment with stronger heat dissipation capacity, the investment cost of the cooling equipment is reduced, and each wheel 100 is controlled by one steering machine 41, so that the steering of the vehicle is more flexible, and the steering with small rotating radius can be realized.

The distributed four-wheel-drive pure range extending system further comprises a brake assembly, the brake assembly comprises a brake control module 61 and four brake motor assemblies 62, the brake control module 61 is electrically connected with the whole vehicle control module 51 and the four brake motor assemblies 62 respectively, each brake motor assembly 62 corresponds to one wheel 100, and the four brake motor assemblies 62 are electrically connected with the power battery 22 and the generator 33. Specifically, each brake motor assembly 62 includes a brake motor body, a brake caliper connected to the brake motor body, and a friction plate connected to the brake caliper, the brake motor body is electrically connected to the brake control module 61 through a low-voltage wire harness, and when the brake motor assembly 62 brakes, the brake motor body can apply pressure on the friction plate through the brake caliper, so that the friction plate contacts with the wheel 100, thereby implementing a braking function of the vehicle.

In the vehicle braking process, the vehicle control module 51 distributes the braking force of each braking motor assembly 62 and the output torque of each in-wheel motor 11 according to the deceleration requirement of the vehicle, so as to fully utilize the braking capability of each wheel 100; in the vehicle braking process, when the wheel 100 is in a locking state, the whole vehicle control module 51 coordinates the braking force of each braking motor assembly 62 and the output torque of each in-wheel motor 11 to prevent the wheel 100 from being locked; during the braking process of the vehicle, when the lateral force of the wheel 100 is insufficient, the whole vehicle control module 51 controls the brake motor assembly 62 to apply the braking force and controls the output torque of the in-wheel motor 11 to prevent the wheel 100 from slipping laterally.

When at least one wheel 100 slips during the process of vehicle acceleration or passing through a wet road surface, the whole vehicle control module 51 reduces the output torque of the hub motor 11 corresponding to the slipped wheel 100 through the motor control module, or the whole vehicle control module 51 controls the brake motor assembly 62 corresponding to the slipped wheel 100 to output the brake force through the brake control module 61.

Specifically, once one or at least two wheels 100 are accelerated or slip on a wet road surface, the entire vehicle control module 51 reduces the output torque of the in-wheel motor 11 corresponding to the slipping wheel 100 through the motor control module, so that the rotation speed of the wheel 100 is reduced, or reduces the rotation speed of the wheel 100 through braking the brake motor assembly 62 corresponding to the wheel 100, so that the probability of the wheel 100 slipping is reduced.

The distributed four-wheel drive pure range extending system further comprises an engine control module 52 electrically connected with the whole vehicle control module 51, the engine control module 52 is electrically connected with the engine 32, and the engine control module 52 is configured to control the engine 32 to be electrically connected with the generator 33 when the electric quantity of the power battery 22 is lower than a preset low electric quantity, and control the engine 32 to be electrically disconnected with the generator 33 until the electric quantity of the power battery 22 reaches a preset high electric quantity. Specifically, in the present embodiment, the preset high power level is that the power of the power battery 22 reaches 90% of the full power level, and the preset low power level is that the power of the power battery 22 reaches 30% of the full power level, that is, the electrical connection state between the generator 33 and the engine 32 is related to the power of the power battery 22, if the power of the power battery 22 is low, the generator 33 is connected to the engine 32, and then the generator 33 can generate electricity; if the power battery 22 has a high electric quantity, the generator 33 does not need to be connected with the engine 32, and the power battery 22 directly provides electric energy for the electric equipment of the vehicle.

The distributed four-wheel drive pure range extending system further comprises a direct current converter 53, the direct current converter 53 is electrically connected with a whole vehicle control module 51, the direct current converter 53, a motor control module, a battery control module 21, a power generation control module 31, a steering control module, a whole vehicle control module 51, a brake control module 61 and an engine control module 52 are integrated in a power domain controller, the direct current converter 53 can convert high-voltage direct current into low-voltage direct current so as to be used by electric equipment, and the power domain controller has a wireless signal receiving function.

When the engine 32 is stopped and the vehicle enters a coasting phase, the in-wheel motor 11 is configured to convert kinetic energy of the wheels 100 into electrical energy and store the electrical energy in the power battery 22. That is, when the engine 32 and the generator 33 are both stopped, the four in-wheel motors 11 can convert kinetic energy of the four wheels 100 of the vehicle into electric energy, respectively, and store the electric energy in the power battery 22, while the power battery 22 is in a charged state and the vehicle is in a braking energy recovery mode.

The steering control module of this embodiment includes a steering main control module 42, a front steering control module 43 and a rear steering control module 44, the steering main control module 42 is electrically connected to the vehicle control module 51, the front steering control module 43 and the rear steering control module 44, the front steering control module 43 is electrically connected to the steering gears 41 corresponding to the two front wheels, and the rear steering control module 44 is electrically connected to the steering gears 41 corresponding to the two rear wheels. That is, the steering main control module 42 controls the two steering gears 41 corresponding to the two front wheels through the front steering control module 43 so that each of the in-wheel motors 11 can brake one front wheel, respectively, and the steering main control module 42 controls the two steering gears 41 corresponding to the two rear wheels through the rear steering control module 44 so that each of the steering gears 41 can brake one rear wheel, respectively.

The distributed four-wheel-drive pure range extending system of the embodiment has a pure electric drive mode, a range extending mode, an off-road mode, a braking energy recovery mode and an idle speed power generation mode, specifically, in the pure electric drive mode, when the energy of the power battery 22 is high, the engine 32 is stopped, the power battery 22 supplies energy to the motor control module to control the in-wheel motor 11 to work, and the power is transmitted to the wheel 100 through the output shaft of the in-wheel motor 11, so that the wheel 100 rotates. The pure electric drive mode comprises a pure electric front drive mode, a pure electric rear drive mode and a pure electric four-wheel drive mode, wherein the pure electric front drive mode and the pure electric rear drive mode belong to a pure electric two-wheel drive mode, the pure electric front drive mode refers to the condition that an engine 32 and a generator 33 are both stopped, a power battery 22 discharges electricity, so that the front double-motor controller 12 controls two front wheels to rotate, the two rear wheels rotate along with the rotation of the front wheels, and the pure electric front drive mode belongs to a pure electric front drive mode; the pure electric rear-drive mode means that the engine 32 and the generator 33 are both stopped, the power battery 22 discharges, so that the rear dual-motor controller 13 controls the two rear wheels to rotate, and at the moment, the two front wheels rotate along with the rotation of the following wheels, and at the moment, the two front wheels belong to the rear-drive mode; the pure electric four-wheel drive mode means that the engine 32 and the generator 33 are both stopped, the power battery 22 is discharged, so that the front dual-motor controller 12 and the rear dual-motor controller 13 control two wheels 100 to rotate simultaneously, and at the moment, the four wheels 100 are all driven, and at the moment, the four-wheel drive mode is adopted.

Specifically, the range extending mode is that the electric quantity of the power battery 22 is insufficient, the engine 32 works and drives the generator 33 to generate electricity, the generator 33 transmits the electricity to the motor control module after generating electricity, and the motor control module controls the in-wheel motor 11 to work, so that the wheel 100 rotates, at this time, the power battery 22 can be charged or standby, and is specifically determined according to the electric quantity generated by the generator 33 and the electric quantity consumed by the equipment. The range-increasing mode comprises a series front driving mode, a series rear driving mode and a series four-driving mode, wherein the series front driving mode and the series rear driving mode belong to a range-increasing two-driving mode, the working conditions of a motor control module, a front wheel, a rear wheel and a hub motor 11 are the same as those of a pure front driving mode in the series front driving mode, the engine 32 and the generator 33 work at the moment, the power battery 22 can be charged or standby, and the range-increasing two-driving mode is realized at the moment; in the series rear-drive mode, the working conditions of the motor control module, the front wheel, the rear wheel and the in-wheel motor 11 are the same as those of the pure electric rear-drive mode, at the moment, the engine 32 and the generator 33 work, the power battery 22 can be charged or standby, and at the moment, the two-drive mode with the increased range is adopted; the series four-wheel drive mode is also called a range-extended four-wheel drive mode, and in the series four-wheel drive mode, the working conditions of the motor control module, the front wheel, the rear wheel and the in-wheel motor 11 are the same as those in the pure four-wheel drive mode, at this time, the engine 32 and the generator 33 work, the power battery 22 can be charged or standby, and at this time, the range-extended four-wheel drive mode is adopted.

The off-road mode of the embodiment is that under the condition that any wheel 100 slips, the motor control module can control other in-wheel motors 11 to work, so as to escape from driving the wheel 100, and the off-road mode includes an off-road four-wheel drive mode, an off-road three-wheel drive mode, an off-road front-wheel drive mode, an off-road rear-wheel drive mode, an off-road oblique two-wheel drive mode and an off-road single-wheel drive mode. In the off-road mode, the engine 32 and the generator 33 can not work, and the electric energy required by the motor control module and the hub motor 11 is provided by the power battery 22; it is also possible that both the engine 32 and the generator 33 are operated, and the generator 33 directly supplies power to the motor control module and the in-wheel motor 11, and at this time, the power battery 22 is in a standby or charging state.

Specifically, the cross-country four-wheel drive mode means that when the four wheels 100 all slip slightly, the working conditions of the motor control module, the front wheels, the rear wheels and the hub motor 11 are all the same as those of the pure electric four-wheel drive mode, and at this time, the four-wheel drive mode is adopted; the cross-country three-wheel drive mode is that when one wheel 100 slips, the motor control module controls the other three in-wheel motors 11 to drive the wheel 100 to rotate, at the moment, the three wheels 100 are all driven, and one slipping wheel 100 is in a follow-up state and belongs to a three-wheel drive mode; the cross-country two-wheel drive mode is that when two wheels 100 slip, the motor control module controls the other two in-wheel motors 11 to drive the wheels 100 to rotate, at the moment, the two wheels 100 are both driven, and the two slipping wheels 100 are both in a follow-up state and belong to a two-wheel drive mode; the cross-country single-drive mode is that when three wheels 100 skid, the motor control module controls the remaining one in-wheel motor 11 to drive the wheels 100 to rotate, at the moment, one wheel 100 is driven, and the three skid wheels 100 are all in a follow-up state, and belong to a single-drive mode.

The braking energy recovery mode of the present embodiment means that when both the engine 32 and the generator 33 are stopped, the four in-wheel motors 11 can respectively convert the kinetic energy of the four wheels 100 of the vehicle into electric energy and store the electric energy in the power battery 22, and at this time, the power battery 22 is in a charging state.

The idle power generation mode of the present embodiment means that the engine 32 and the generator 33 are both operated, and the generator 33 can store the converted electric energy in the power battery 22 through the high-voltage wire harness, and at this time, the in-wheel motor 11 of each wheel 100 is in a stopped state, and the power battery 22 is in a charged state.

The embodiment also provides a control method applicable to the distributed four-wheel drive pure range extending system in the above scheme, and the method includes the steps of:

s1, the whole vehicle control module 51 calculates the required driving power and the required output torque of the vehicle;

s2, determining whether one of a preset high discharge power of the power battery 22 being less than the required driving power and an electric quantity of the power battery 22 reaching or being less than a preset low electric quantity occurs, if so, executing S3; if not, go to S4;

s3, judging whether the speed of the vehicle is zero or not, and if so, enabling the vehicle to enter an idle speed power generation mode; if not, the engine 32 drives the generator 33 to generate power, and S4 is executed;

s4, judging whether the vehicle enters the off-road mode, if so, executing S5; if not, go to S6;

s5, selecting one of the cross-country single-wheel drive mode, the cross-country two-wheel drive mode, the cross-country three-wheel drive mode and the cross-country four-wheel drive mode according to the slip state of the wheels 100, and executing S7;

s6, judging whether the vehicle selects a four-wheel drive mode, if so, entering the four-wheel drive mode; if not, the vehicle enters a two-wheel drive mode, and S7 is executed;

and S7, the whole vehicle control module 51 judges whether the current running state of the vehicle meets the driving requirement, and if not, the control returns to S2.

Wherein, S2 includes the following steps:

s21, judging whether the preset high discharge power of the power battery 22 is smaller than the required driving power, if so, not starting the engine 32 and executing S3; if not, go to S22;

s22, judging whether the electric quantity of the power battery 22 reaches or is lower than a preset low electric quantity, if so, executing S3; if not, the engine 32 is started and S4 is executed.

Before S1, the vehicle is started, and after the power domain controller receives the start high-voltage power-on signal, the power domain controller sends a high-voltage power-on command to the power battery 22, the in-wheel motor 11, the dc converter 53, and the generator 33, respectively. After the high-voltage electrification is finished, the vehicle has a running condition.

The control method of the distributed four-wheel drive pure range extending system provided by the embodiment can select the current running mode of the vehicle according to the electric quantity of the power battery 22, so that the electric quantity of the power battery 22 is always maintained in a proper electric quantity range, and when at least one wheel 100 of the vehicle slips, the vehicle can select one of an off-road single-wheel drive mode, an off-road two-wheel drive mode, an off-road three-wheel drive mode and an off-road four-wheel drive mode, so that the vehicle is out of the trouble.

Specifically, the off-road two-wheel drive mode in S5 includes an off-road front-wheel drive mode, an off-road rear-wheel drive mode and an off-road diagonal two-wheel drive mode, when both rear wheels slip, the off-road front-wheel drive mode is executed in S5, and the motor control module controls the operation of the in-wheel motors 11 corresponding to the two front wheels; when both the two front wheels slip, the cross-country rear drive mode is executed in S5, and the motor control module controls the in-wheel motors 11 corresponding to the two rear wheels to operate; when both the wheels 100 on the diagonal of the vehicle slip, the diagonal two-drive mode is performed in S5, and the motor control module controls the in-wheel motors 11 corresponding to the other two wheels 100 on the diagonal of the vehicle to operate.

When three wheels 100 slip, the off-road single-drive mode is executed in S5, and the motor control module controls the operation of the remaining one of the in-wheel motors 11 corresponding to the wheels 100; when one wheel 100 slips, the cross-country three-wheel drive mode is executed in S5, and the motor control module controls the operation of the remaining three in-wheel motors 11 corresponding to the wheel 100; when all four wheels 100 slip, the off-road four-wheel drive mode can be performed in S5, and the motor control module controls the four in-wheel motors 11 corresponding to the wheels 100 to operate.

The four-wheel drive mode of the embodiment comprises a range-extended four-wheel drive mode and a pure electric four-wheel drive mode, the two-wheel drive mode comprises a pure electric two-wheel drive mode and a range-extended two-wheel drive mode, the pure electric two-wheel drive mode comprises a pure electric front drive mode and a pure electric rear drive mode, the range-extended two-wheel drive mode comprises a range-extended front drive mode and a range-extended rear drive mode, and when S6 is executed by S4 from S2, the vehicle enters the pure electric four-wheel drive mode or the pure electric two-wheel drive mode; when the vehicle passes through S4 from S3 and executes S6, the vehicle enters the range-extended four-wheel drive mode or the range-extended two-wheel drive mode.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A distributed four-wheel drive pure range extending system is characterized by comprising:

the driving assembly comprises a motor control module and four hub motors (11), wherein the motor control module comprises a front double-motor controller (12) and a rear double-motor controller (13), the front double-motor controller (12) is respectively and electrically connected with the two hub motors (11) corresponding to two front wheels through high-voltage wires, the rear double-motor controller (13) is respectively and electrically connected with the two hub motors (11) corresponding to two rear wheels through high-voltage wires, and when at least one wheel (100) slips, the motor control module is configured to control the other hub motors (11) to drive the wheel (100) to rotate;

the battery assembly comprises a battery control module (21) and power batteries (22), wherein the battery control module (21) is electrically connected with the power batteries (22), and the power batteries (22) are electrically connected with the four motor control modules through high-voltage wires;

the range extending assembly comprises a power generation control module (31), an engine (32) and a generator (33) electrically connected with the power battery (22) through a high-voltage line, wherein the power generation control module (31) is electrically connected with the generator (33), the engine (32) is in transmission connection with the generator (33), the generator (33) is electrically connected with the hub motor (11), and when the electric quantity of the power battery (22) is lower than a preset low electric quantity, the power generation control module (31) is configured to control the generator (33) or the hub motor (11) to generate electricity and store electric energy to the power battery (22);

a steering assembly including a steering control module and four steering machines (41), the four steering machines (41) being electrically connected to the steering control module and the power battery (22), each steering machine (41) corresponding to one of the wheels (100), the steering control module being configured to calculate a steering torque and a steering angle of each steering machine (41) and control the steering machines (41) to steer;

and the finished vehicle control module (51) is respectively and electrically connected with the motor control module, the battery control module (21), the power generation control module (31) and the steering control module.

2. The distributed four-wheel drive pure range extending system according to claim 1, further comprising a brake assembly, wherein the brake assembly comprises a brake control module (61) and four brake motor assemblies (62), the brake control module (61) is electrically connected with the entire vehicle control module (51) and the four brake motor assemblies (62) respectively, each brake motor assembly (62) is arranged corresponding to one wheel (100), and the four brake motor assemblies (62) are electrically connected with the power battery (22) and the generator (33);

when the vehicle accelerates or at least one appears in the process of passing through wet and slippery road surface when wheel (100) skids the condition, whole car control module (51) passes through motor control module reduces and skids wheel (100) correspond the output torque of in-wheel motor (11), or whole car control module (51) passes through brake control module (61) control and skid wheel (100) correspond brake motor subassembly (62) output brake force.

3. The distributed four-wheel drive only range extending system according to claim 2, further comprising an engine control module (52) electrically connected with the vehicle control module (51), wherein the engine control module (52) is electrically connected with the engine (32), and the engine control module (52) is configured to control the engine (32) to be electrically connected with the generator (33) when the power battery (22) is lower than a preset low power.

4. The distributed four-wheel drive pure range extending system according to claim 3, further comprising a DC converter (53), wherein the DC converter (53) is electrically connected with the whole vehicle control module (51), and the DC converter (53), the motor control module, the battery control module (21), the power generation control module (31), the steering control module, the whole vehicle control module (51), the brake control module (61) and the engine control module (52) are integrated in a power domain controller.

5. The distributed four-wheel drive pure range extending system according to claim 1, wherein the steering control module comprises a steering main control module (42), a front steering control module (43) and a rear steering control module (44), the steering main control module (42) is respectively connected with the whole vehicle control module (51), the front steering control module (43) and the rear steering control module (44), the front steering control module (43) is respectively electrically connected with the steering machines (41) corresponding to two front wheels, and the rear steering control module (44) is respectively electrically connected with the steering machines (41) corresponding to two rear wheels.

6. A control method suitable for the distributed four-wheel drive pure range extending system according to any one of claims 1-5, characterized by comprising the following steps:

s1, the vehicle control module (51) calculates the required driving power and the required output torque of the vehicle;

s2, judging whether one of the situation that the preset high discharge power of the power battery (22) is smaller than the required driving power and the situation that the electric quantity of the power battery (22) reaches or is lower than the preset low electric quantity occurs, if yes, executing S3; if not, go to S4;

s3, judging whether the speed of the vehicle is zero or not, and if so, enabling the vehicle to enter an idle speed power generation mode; if not, the engine (32) drives the generator (33) to generate power, and S4 is executed;

s5, selecting one of an off-road single-drive mode, an off-road two-drive mode, an off-road three-drive mode and an off-road four-drive mode according to the slip state of the wheel (100), and executing S7;

and S7, the vehicle control module (51) judges whether the current running state of the vehicle meets the driving requirement, if not, the vehicle control module returns to S2.

7. The control method of a distributed four-wheel drive range-only system according to claim 6, wherein the off-road two-drive mode includes an off-road front-drive mode, an off-road rear-drive mode and an off-road diagonal two-drive mode, the off-road front-drive mode is executed in S5 when both rear wheels slip, the motor control module controls the operation of the in-wheel motors (11) corresponding to both front wheels; when both the front wheels slip, the off-road rear drive mode is executed in S5, and the motor control module controls the in-wheel motors (11) corresponding to both the rear wheels to operate; when both of the wheels (100) located on the diagonal line of the vehicle slip, the diagonal two-drive mode is performed in S5, and the motor control module controls the in-wheel motors (11) corresponding to the other two wheels (100) located on the diagonal line of the vehicle to operate.

8. The control method of the distributed four-wheel drive range-only system according to claim 6, wherein when three of the wheels (100) slip, the off-road single drive mode is performed in S5, and the motor control module controls the operation of the remaining one of the in-wheel motors (11) corresponding to the wheels (100); when one of the wheels (100) slips, the off-road three-drive mode is executed in S5, and the motor control module controls the operation of the remaining three in-wheel motors (11) corresponding to the wheels (100); when the four wheels (100) are all slipped, the off-road four-wheel drive mode can be executed in S5, and the motor control module controls the four in-wheel motors (11) corresponding to the wheels (100) to operate.

9. The control method of the distributed four-wheel drive pure range extending system according to claim 6, wherein S2 includes the steps of:

s21, judging whether the preset high discharge power of the power battery (22) is smaller than the required driving power, if so, not starting the engine (32) and executing S3; if not, go to S22;

s22, judging whether the electric quantity of the power battery (22) reaches or is lower than a preset low electric quantity, if so, executing S3; if not, the engine (32) is started and S4 is executed.

10. The control method of the distributed four-wheel drive pure range extending system according to claim 6, wherein the four-wheel drive mode comprises a range extending four-wheel drive mode and an electric four-wheel drive mode, the two-wheel drive mode comprises an electric two-wheel drive mode and a range extending two-wheel drive mode, the electric two-wheel drive mode comprises an electric front drive mode and an electric rear drive mode, the range extending two-wheel drive mode comprises a range extending front drive mode and a range extending rear drive mode, and when a vehicle passes through S4 and executes S6 from S2, the vehicle enters the electric four-wheel drive mode or the electric two-wheel drive mode; when the vehicle passes through S4 from S3 and executes S6, the vehicle enters the range-extended four-wheel drive mode or the range-extended two-wheel drive mode.