CN109572699B

CN109572699B - Hybrid electric vehicle and gear shifting control method and system thereof

Info

Publication number: CN109572699B
Application number: CN201710911836.0A
Authority: CN
Inventors: 王春生; 许伯良; 罗永官; 赵梅君; 刘学礼
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2017-09-29
Filing date: 2017-09-29
Publication date: 2020-10-23
Anticipated expiration: 2037-09-29
Also published as: TW201914874A; CN109572699A; WO2019062879A1

Abstract

The invention discloses a hybrid electric vehicle and a gear shifting control method and a gear shifting control system thereof, wherein the hybrid electric vehicle comprises an engine, a power motor, a power battery, a transmission and an auxiliary motor connected with the engine, and the gear shifting control method comprises the following steps: when the engine runs, the speed of the hybrid electric vehicle is obtained through the transmission control unit, and the rotating speed of the engine is obtained through the engine control unit; judging whether the assisted gear shifting condition is met or not according to the speed of the hybrid electric vehicle and the rotating speed of the engine; if the assisted gear shifting condition is met, the whole vehicle control unit generates an assisted gear shifting instruction and sends the assisted gear shifting instruction to the auxiliary motor control unit so as to control the auxiliary motor to output torque to the engine and accelerate gear shifting of the transmission. According to the gear shifting control method, the gear shifting time of the hybrid electric vehicle can be effectively shortened, the driving experience of a user is improved, and meanwhile, the service life of the clutch is prolonged.

Description

Hybrid electric vehicle and gear shifting control method and system thereof

Technical Field

The invention relates to the technical field of hybrid electric vehicles, in particular to a gear shifting control method of a hybrid electric vehicle, a non-transitory computer readable storage medium, a gear shifting control system of a hybrid electric vehicle and a hybrid electric vehicle.

Background

During the gear shifting process of the transmission, the rotation speed of the engine is required to be increased or decreased to reach the rotation speed corresponding to the target gear, the process is generally realized through the interaction between the clutch and the engine, the duration is relatively long, and a user generally obviously feels that the power is weakened. In addition, in the gear shifting process, the sliding and grinding work of the clutch is relatively large, so that the abrasion of the clutch can be accelerated, and the service life of the clutch is shortened.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the art described above. Therefore, an object of the present invention is to provide a shift control method for a hybrid vehicle, which can effectively shorten the shift time of the hybrid vehicle, improve the driving experience of the user, and help to prolong the service life of the clutch.

A second object of the invention is to propose a non-transitory computer-readable storage medium.

A third object of the present invention is to provide a shift control system for a hybrid vehicle.

A fourth object of the present invention is to provide a hybrid vehicle.

In order to achieve the above object, a first aspect of the present invention provides a shift control method for a hybrid vehicle, where the hybrid vehicle includes an engine, a power motor, a power battery, a DC-DC converter, a transmission, and a sub-motor connected to the engine, the engine outputs power to wheels of the hybrid vehicle through a clutch and the transmission, the power motor is configured to output driving power to the wheels of the hybrid vehicle, the power battery is configured to supply power to the power motor, the sub-motor is connected to the power motor, the DC-DC converter, and the power battery, and the sub-motor generates power under the driving of the engine, the shift control method includes the following steps: when the engine runs, acquiring the speed of the hybrid electric vehicle through a transmission control unit, and acquiring the rotating speed of the engine through an engine control unit; judging whether the assisted gear shifting condition is met or not according to the speed of the hybrid electric vehicle and the rotating speed of the engine; if the assisted gear shifting condition is met, the whole vehicle control unit generates an assisted gear shifting instruction and sends the assisted gear shifting instruction to the auxiliary motor control unit so as to control the auxiliary motor to output torque to the engine and accelerate gear shifting of the transmission.

According to the gear shifting control method of the hybrid electric vehicle, the gear shifting assisting condition is judged whether to be met or not according to the acquired speed and the acquired rotating speed of the hybrid electric vehicle, and the auxiliary motor is controlled to output the torque to the engine when the gear shifting assisting condition is met, so that the gear shifting time of the hybrid electric vehicle can be effectively shortened, the driving experience of a user is improved, meanwhile, the abrasion to a clutch can be reduced, and the service life of the clutch can be prolonged.

To achieve the above object, a non-transitory computer-readable storage medium is provided in an embodiment of a second aspect of the present invention, and a computer program is stored thereon, and when executed by a processor, the non-transitory computer-readable storage medium implements the shift control method for a hybrid vehicle according to the embodiment of the first aspect of the present invention.

According to the non-transitory computer readable storage medium of the embodiment of the invention, the stored computer program is executed, so that the gear shifting time of the hybrid electric vehicle can be effectively shortened, the driving experience of a user is improved, meanwhile, the abrasion to the clutch can be reduced, and the service life of the clutch can be prolonged.

In order to achieve the above object, a third aspect of the present invention provides a shift control system for a hybrid vehicle, wherein the hybrid vehicle includes an engine, a power motor, a power battery, a DC-DC converter, a transmission, and a sub-motor connected to the engine, the engine outputs power to wheels of the hybrid vehicle through a clutch and the transmission, the power motor is configured to output driving power to the wheels of the hybrid vehicle, the power battery is configured to supply power to the power motor, the sub-motor is connected to the power motor, the DC-DC converter, and the power battery, and the sub-motor is configured to generate power under the driving of the engine, the shift control system includes: a transmission control unit for acquiring a vehicle speed of the hybrid vehicle; an engine control unit for acquiring a rotation speed of the engine; the whole vehicle control unit is used for judging whether a shift assisting condition is met or not according to the speed of the hybrid electric vehicle and the rotating speed of the engine and generating a shift assisting instruction when the shift assisting condition is met; and the auxiliary motor control unit is used for receiving and executing the auxiliary gear shifting command so as to control the auxiliary motor to output torque to the engine and accelerate gear switching of the transmission.

According to the gear shifting control system of the hybrid electric vehicle, the speed of the hybrid electric vehicle and the rotating speed of the engine are respectively obtained through the transmission control unit and the engine control unit, whether the gear shifting assisting condition is met or not is judged through the vehicle control unit according to the speed and the rotating speed, and when the gear shifting assisting condition is met, the auxiliary motor control unit controls the auxiliary motor to output torque to the engine, so that the gear shifting time of the hybrid electric vehicle can be effectively shortened, the driving experience of a user is improved, meanwhile, the abrasion to a clutch can be reduced, and the service life of the clutch can be prolonged.

In order to achieve the above object, a fourth aspect of the present invention provides a hybrid vehicle including the shift control system of the hybrid vehicle according to the third aspect of the present invention.

According to the hybrid electric vehicle disclosed by the embodiment of the invention, the gear shifting time can be effectively shortened, the driving experience of a user is improved, meanwhile, the abrasion to the clutch can be reduced, and the service life of the clutch can be prolonged.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

Fig. 1 is a schematic structural view of a hybrid vehicle according to an embodiment of the invention;

fig. 2 is a schematic structural view of a hybrid vehicle according to an embodiment of the invention;

FIG. 3 is a flowchart of a shift control method of a hybrid vehicle according to an embodiment of the present invention;

FIG. 4 is a flowchart of a method for detecting a communication status between a vehicle control unit and a secondary motor control unit in accordance with one embodiment of the present invention;

FIG. 5 is a flowchart of a method of detecting a communication status between a vehicle control unit and an engine control unit in accordance with one embodiment of the present invention;

FIG. 6 is a flowchart of a method of detecting a communication status between a vehicle control unit and a transmission control unit in accordance with one embodiment of the present invention;

FIG. 7 is a flowchart of a method of determining whether assisted shift conditions are met, in accordance with an embodiment of the present invention;

FIG. 8 is a flowchart of a method of implementing a control to assist a shift in accordance with a specific embodiment of the present invention;

FIG. 9 is a block schematic diagram of a shift control system for a hybrid vehicle according to an embodiment of the present invention;

fig. 10 is a block schematic diagram of a hybrid vehicle according to an embodiment of the invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In one embodiment of the present invention, as shown in fig. 1, a hybrid vehicle may include an engine 1, a power motor 2, a power battery 3, and a sub-motor 4 connected to the engine 1, wherein the power motor 2 and the sub-motor 4 are both connected to the power battery 3. Further, as shown in fig. 2, the hybrid vehicle may further include a DC-DC converter 5 and a transmission 6, wherein the engine 1 outputs power to wheels of the hybrid vehicle through the clutch and the transmission 6, the power motor 2 is configured to output driving force to the wheels of the hybrid vehicle, the power battery 3 is configured to supply power to the power motor 2, the sub-motor 4 is connected to the power motor 2, the DC-DC converter 5 and the power battery 3, respectively, and the sub-motor 4 is driven by the engine 1 to operate with negative torque to generate power. Wherein, the electric energy generated by the sub-motor 4 can be supplied to at least one of the power battery 3, the power motor 2, the DC-DC converter 5, the low-voltage load 7, and the high-voltage load (not shown in the figure). The low-voltage load 7 may include, but is not limited to, a vehicle lamp, a radio, and the like, and the high-voltage load may include, but is not limited to, a vehicle air conditioner, and the like.

From this, driving motor 2 and auxiliary motor 4 correspond respectively and act as driving motor and generator, because auxiliary motor 4 has higher generating power and generating efficiency during low-speed to can satisfy the power consumption demand that the low-speed traveles, can maintain whole car low-speed electric balance, maintain whole car low-speed ride comfort, promote the dynamic behavior of whole car.

In some embodiments, the secondary electric machine 4 may be a BSG (Belt-driven Starter Generator) electric machine. It should be noted that the auxiliary motor 4 belongs to a high-voltage motor, for example, the generated voltage of the auxiliary motor 4 is equivalent to the voltage of the power battery 3, so that the electric energy generated by the auxiliary motor 4 can directly charge the power battery 3 without voltage conversion, and can also directly supply power to the power motor 2 and/or the DC-DC converter 5. The auxiliary motor 4 also belongs to a high-efficiency generator, and for example, the auxiliary motor 4 is driven to generate electricity at the idle speed of the engine 1, so that the electricity generation efficiency of more than 97% can be realized.

The BSG motor is relatively closely connected with the power of the engine, so that the hybrid electric vehicle, the gear shifting control method and the gear shifting control system are more suitable for implementing the hybrid electric vehicle and the gear shifting control method and the gear shifting control system.

The hybrid vehicle and the shift control method and system thereof according to the embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 3 is a flowchart of a shift control method of a hybrid vehicle according to an embodiment of the present invention.

As shown in fig. 3, the shift control method for a hybrid vehicle according to the embodiment of the present invention includes the following steps:

and S1, when the engine runs, acquiring the speed of the hybrid electric vehicle through the transmission control unit, and acquiring the rotating speed of the engine through the engine control unit.

And S2, judging whether the shift assisting condition is met or not according to the speed of the hybrid electric vehicle and the rotating speed of the engine.

When the gear shift control is performed, it is first possible to confirm whether communication between each control unit that performs the gear shift control in a CAN (Controller Area Network) Network is normal, and whether a device that finally performs the gear shift control action is malfunctioning. Therefore, in an embodiment of the present invention, before determining whether the assisted gear shifting condition is satisfied, the communication states between the vehicle control unit and the sub motor control unit, between the vehicle control unit and the engine control unit, and between the vehicle control unit and the transmission control unit may be detected, and the fault states of the sub motor and the sub motor control unit may be detected. Then, whether the shift assisting condition is met can be judged according to the communication state, the fault state, the speed of the hybrid electric vehicle and the rotating speed of the engine.

Specifically, when communication between a finished automobile control unit and an auxiliary motor control unit, between the finished automobile control unit and an engine control unit, and between the finished automobile control unit and a transmission control unit is normal, and the auxiliary motor control unit do not have faults, if the hybrid electric vehicle accelerates and the rotating speed of an engine is greater than a first preset rotating speed, judging that an assisting upshift condition is met; and if the hybrid electric vehicle decelerates and the rotating speed of the engine is less than a second preset rotating speed, judging that the condition of assisting the downshift is met.

And S3, if the assisted gear shifting condition is met, the whole vehicle control unit generates an assisted gear shifting instruction and sends the assisted gear shifting instruction to the auxiliary motor control unit to control the auxiliary motor to output torque to the engine so as to accelerate gear shifting of the transmission.

Specifically, when the condition of assisting the upshift is judged to be met, the whole vehicle control unit generates an assisting upshift instruction and sends the assisting upshift instruction to the auxiliary motor control unit to control the auxiliary motor to output negative torque to the engine, so that the reduction rate of the rotating speed of the engine is increased until the rotating speed of the engine is reduced to a first target rotating speed, wherein the first target rotating speed is the rotating speed of the engine corresponding to the downshift gear.

When the condition of assisting the downshift is judged to be met, the whole vehicle control unit generates an assisting downshift instruction and sends the assisting downshift instruction to the auxiliary motor control unit to control the auxiliary motor to output positive torque to the engine, so that the rising rate of the rotating speed of the engine is increased until the rotating speed of the engine is raised to a second target rotating speed, wherein the second target rotating speed is the rotating speed of the engine corresponding to the shifted gear.

In an embodiment of the present invention, as shown in fig. 4, the communication status between the vehicle control unit and the sub-motor control unit can be detected by the following steps:

s101, the VCU (Vehicle Control Unit) determines whether a BSG message is received. If not, executing step S102; if so, step S103 is performed. In this embodiment, the secondary motor is exemplified as a BSG motor.

S102, the timer accumulates the timing time. Then step S104 is performed.

S103, resetting the timer.

And S104, judging whether the timing time is greater than Cs. Cs is a set time threshold. If not, executing step S105; if so, step S106 is performed.

And S105, judging that the communication between the VCU and the BSG motor control unit is normal.

And S106, judging that the communication between the VCU and the BSG motor control unit is abnormal.

In an embodiment of the present invention, as shown in fig. 5, the communication status between the vehicle Control unit and the engine Control unit ecu (engine Control unit) can be detected by the following steps:

s201, the VCU judges whether an ECU message is received or not. If not, executing step S202; if so, step S203 is performed.

S202, the timer accumulates the timing time. Then, step S204 is performed.

S203, the timer is cleared.

And S204, judging whether the timing time is greater than Cs. If not, go to step S205; if so, step S206 is performed.

And S205, judging that the communication between the VCU and the ECU is normal.

And S206, judging that the communication between the VCU and the ECU is abnormal.

In an embodiment of the present invention, as shown in fig. 6, the communication state between the vehicle Control unit and the transmission Control unit tcu (transmission Control unit) can be detected by the following steps:

s301, the VCU judges whether the TCU message is received. If not, executing step S302; if so, step S303 is performed.

S302, the timer accumulates the timing time. Then, step S304 is performed.

S303, clearing the timer.

S304, judging whether the timing time is greater than Cs. If not, executing step S305; if so, step S306 is performed.

S305, judging that the communication between the VCU and the TCU is normal.

S306, judging the communication abnormality of the VCU and the TCU.

In one embodiment of the present invention, as shown in fig. 7, it can be determined whether the assisted shift condition is satisfied by the following steps:

s401, judging whether the engine is running or not, and judging whether the communication between the VCU and the BSG motor control unit, the ECU and the TCU is normal or not. If yes, go to step S402; if not, step S411 is executed.

S402, judging whether the vehicle is accelerated or not and judging whether the rotating speed of the engine exceeds Brpm or not. Wherein, B is a preset rotating speed threshold value. If yes, go to step S404; if not, step S403 is performed.

And S403, judging whether the vehicle decelerates or not, and judging whether the rotating speed of the engine is reduced to Arpm or not. Wherein A is a preset rotating speed threshold value. If yes, go to step S405; if not, step S408 is performed.

S404, judging whether the BSG self-test is normal. The fault states of the BSG motor and the BSG motor control unit can be detected by an automatic operation detection program of the BSG motor control unit, the process is called BSG self-checking, if the BSG motor and the BSG motor control unit have no fault, the BSG self-checking is normal, and the step S407 can be executed; if the BSG motor or the BSG motor control unit fails, the BSG self-test is abnormal, and step S406 may be performed.

S405, judging whether the BSG self-test is normal. If yes, go to step S409; if not, step S410 is performed.

And S406, the BSG motor assists in gear shifting and is invalid, and the TCU performs gear-up control. That is, when the BSG self-test is abnormal, the assisted shift condition is not satisfied, and the upshift process is performed under the control of the TCU.

And S407, the BSG motor assists in gear shifting.

And S408, disabling the BSG motor assisted gear shifting. The speed of a vehicle does not meet the shift assisting condition, and the BSG motor does not assist the shift.

And S409, assisting the BSG motor in downshifting.

And S410, the BSG motor assists in gear shifting and is invalid, and the TCU performs downshift control. That is, when the BSG self-test is abnormal, the shift assist condition is not satisfied, and the downshift process is controlled by the TCU.

And S411, disabling the BSG motor assisted gear shifting. The communication between the VCU and the BSG motor control unit is abnormal, or the communication between the VCU and the ECU is abnormal, or the communication between the VCU and the TCU is abnormal, namely the communication state between each control unit executing the gear shifting control in the CAN network does not meet the gear shifting assisting condition, and the BSG motor does not assist the gear shifting, namely the gear shifting control method of the embodiment of the invention is not continuously executed.

In one embodiment of the present invention, as shown in fig. 8, the control to assist the shift may be achieved by:

s501, the BSG motor control unit judges whether a assistant gear-up instruction is received. If not, executing step S502; if so, step S503 is executed.

S502, the BSG motor control unit judges whether a downshift assisting instruction is received. If not, executing step S504; if so, step S505 is performed.

And S503, controlling the BSG motor to run with negative torque, and withdrawing after the rotating speed of the engine is reduced to the first target rotating speed. The BSG motor is controlled to run with negative torque, braking torque is applied to the engine, and therefore the reduction rate of the rotating speed of the engine is increased until the rotating speed of the engine is reduced to the rotating speed corresponding to the target gear. It should be appreciated that due to the negative torque operation of the BSG motor, the BSG motor may generate power simultaneously during the assisted upshift of the BSG motor, enabling a portion of the energy to be recovered.

And S504, the BSG motor assists in gear shifting and is invalid, and the output torque of the BSG motor is 0.

And S505, controlling the BSG motor to operate at positive torque, and withdrawing after the rotating speed of the engine is increased to a second target rotating speed. And applying driving torque to the engine by controlling the positive torque operation of the BSG motor so as to improve the rising rate of the rotating speed of the engine until the rotating speed of the engine is raised to the rotating speed corresponding to the target gear.

In summary, according to the shift control method of the hybrid electric vehicle in the embodiment of the invention, the vehicle speed and the rotation speed of the engine of the hybrid electric vehicle are acquired, whether the shift assisting condition is met or not is judged according to the acquired vehicle speed and rotation speed, and the auxiliary motor is controlled to output the torque to the engine when the shift assisting condition is met, so that the shift time of the hybrid electric vehicle can be effectively shortened, the driving experience of a user is improved, meanwhile, the wear of the clutch can be reduced, and the service life of the clutch can be prolonged.

The invention also provides a non-transitory computer readable storage medium corresponding to the above embodiment.

A non-transitory computer-readable storage medium of an embodiment of the present invention has stored thereon a computer program that, when executed by a processor, implements the shift control method for a hybrid vehicle set forth in the above-described embodiment of the present invention.

Corresponding to the embodiment, the invention further provides a gear shifting control system of the hybrid electric vehicle.

As shown in fig. 9, a shift control system 100 for a hybrid vehicle according to an embodiment of the present invention includes a transmission control unit 10, an engine control unit 20, a vehicle control unit 30, and a sub motor control unit 40.

The transmission control unit 10 is used for acquiring the speed of the hybrid electric vehicle; the engine control unit 20 is used for acquiring the rotating speed of the engine; the whole vehicle control unit 30 is configured to determine whether the shift assist condition is satisfied according to the speed of the hybrid electric vehicle and the rotational speed of the engine, and generate a shift assist instruction when the shift assist condition is satisfied; the auxiliary motor control unit 40 is configured to receive and execute an assist shift instruction to control the auxiliary motor to output torque to the engine to accelerate gear shifting of the transmission.

When the gear shifting control is carried out, whether the communication between each control unit executing the gear shifting control in the CAN network is normal or not and whether the device finally executing the gear shifting control action breaks down or not CAN be confirmed. Therefore, in an embodiment of the present invention, before determining whether the shift assist condition is satisfied, the entire vehicle control unit 30 may further detect communication states with the sub-motor control unit 40, the engine control unit 20, and the transmission control unit 10, respectively, the sub-motor control unit 40 is further configured to detect fault states of the sub-motor and the sub-motor control unit 40, and then the entire vehicle control unit 30 may determine whether the shift assist condition is satisfied according to the communication states, the fault states, the vehicle speed of the hybrid vehicle, and the engine speed.

Specifically, when the communication between the vehicle control unit 30 and the sub-motor control unit 40, the communication between the vehicle control unit 30 and the engine control unit 20, and the communication between the vehicle control unit 30 and the transmission control unit 10 are normal and the sub-motor and sub-motor control unit 40 does not fail, the vehicle control unit 30 determines that the assist upshift condition is satisfied when the hybrid vehicle is accelerated and the rotation speed of the engine is greater than a first preset rotation speed, and determines that the assist downshift condition is satisfied when the hybrid vehicle is decelerated and the rotation speed of the engine is less than a second preset rotation speed.

When the condition of assisting the upshift is judged to be met, the entire vehicle control unit 30 may generate an assisting upshift instruction and send the assisting upshift instruction to the auxiliary motor control unit 40, and the auxiliary motor control unit 40 receives and executes the assisting upshift instruction to control the auxiliary motor to output a negative torque to the engine, so as to increase a reduction rate of the rotation speed of the engine until the rotation speed of the engine is reduced to a first target rotation speed, where the first target rotation speed is the rotation speed of the engine corresponding to the downshift gear.

When the condition of assisting the downshift is judged to be met, the entire vehicle control unit 30 may generate an instruction of assisting the downshift and send the instruction of assisting the downshift to the auxiliary motor control unit 40, and the auxiliary motor control unit 40 receives and executes the instruction of assisting the downshift to control the auxiliary motor to output a positive torque to the engine, so as to increase the rising rate of the rotation speed of the engine until the rotation speed of the engine rises to a second target rotation speed, where the second target rotation speed is the rotation speed of the engine corresponding to the shifted gear.

For further implementation of the shift control system of the hybrid electric vehicle according to the embodiment of the present invention, reference may be made to the contents disclosed in the shift control method of the hybrid electric vehicle, and details thereof are not repeated herein.

The invention further provides a hybrid electric vehicle corresponding to the embodiment.

As shown in fig. 10, a hybrid vehicle 1000 according to an embodiment of the present invention includes a shift control system 100 for a hybrid vehicle according to the above embodiment of the present invention.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A gear shifting control method of a hybrid electric vehicle is characterized in that the hybrid electric vehicle comprises an engine, a power motor, a power battery, a DC-DC converter, a transmission and an auxiliary motor connected with the engine, the engine outputs power to wheels of the hybrid electric vehicle through a clutch and the transmission, the power motor is used for outputting driving force to the wheels of the hybrid electric vehicle, the power battery is used for supplying power to the power motor, the auxiliary motor is respectively connected with the power motor, the DC-DC converter and the power battery, the auxiliary motor generates power under the driving of the engine, and the gear shifting control method comprises the following steps:

when the engine runs, acquiring the speed of the hybrid electric vehicle through a transmission control unit, and acquiring the rotating speed of the engine through an engine control unit;

respectively detecting the communication states between a finished automobile control unit and an auxiliary motor control unit, between the finished automobile control unit and the engine control unit and between the finished automobile control unit and the transmission control unit;

detecting a fault state of the secondary motor and the secondary motor control unit;

judging whether a shift assisting condition is met or not according to the communication state, the fault state, the speed of the hybrid electric vehicle and the rotating speed of the engine;

if the assisted gear shifting condition is met, the whole vehicle control unit generates an assisted gear shifting instruction and sends the assisted gear shifting instruction to an auxiliary motor control unit so as to control the auxiliary motor to output torque to the engine and accelerate gear shifting of the transmission;

wherein when the communication between the whole vehicle control unit and the auxiliary motor control unit, between the whole vehicle control unit and the engine control unit and between the whole vehicle control unit and the transmission control unit is normal and the auxiliary motor control unit do not have faults,

if the hybrid electric vehicle is accelerated and the rotating speed of the engine is greater than a first preset rotating speed, judging that a condition for assisting the upshift is met;

and if the hybrid electric vehicle decelerates and the rotating speed of the engine is less than a second preset rotating speed, judging that the condition of assisting the downshift is met.

2. The shift control method for a hybrid vehicle according to claim 1, wherein when it is determined that the assist upshift condition is satisfied, the vehicle control unit generates an assist upshift instruction and sends the assist upshift instruction to the sub-motor control unit to control the sub-motor to output a negative torque to the engine until the rotation speed of the engine is reduced to a first target rotation speed.

3. The shift control method of a hybrid vehicle according to claim 1, wherein when it is determined that the assisted downshift condition is satisfied, the vehicle control unit generates an assisted downshift instruction and sends the assisted downshift instruction to the sub-motor control unit to control the sub-motor to output a positive torque to the engine until the rotational speed of the engine is increased to a second target rotational speed.

4. A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that the program, when executed by a processor, implements a shift control method of a hybrid vehicle according to any one of claims 1-3.

5. A gear shifting control system of a hybrid electric vehicle is characterized in that the hybrid electric vehicle comprises an engine, a power motor, a power battery, a DC-DC converter, a transmission and an auxiliary motor connected with the engine, the engine outputs power to wheels of the hybrid electric vehicle through a clutch and the transmission, the power motor is used for outputting driving force to the wheels of the hybrid electric vehicle, the power battery is used for supplying power to the power motor, the auxiliary motor is respectively connected with the power motor, the DC-DC converter and the power battery, the auxiliary motor generates power under the driving of the engine, and the gear shifting control system comprises:

a transmission control unit for acquiring a vehicle speed of the hybrid vehicle;

an engine control unit for acquiring a rotation speed of the engine;

the whole vehicle control unit is used for respectively detecting the communication states between the whole vehicle control unit and the auxiliary motor control unit, between the whole vehicle control unit and the engine control unit and between the whole vehicle control unit and the transmission control unit;

the auxiliary motor control unit is used for detecting fault states of the auxiliary motor and the auxiliary motor control unit;

the whole vehicle control unit is also used for judging whether a shift assisting condition is met according to the communication state, the fault state, the vehicle speed of the hybrid electric vehicle and the rotating speed of the engine, and generating a shift assisting instruction when the shift assisting condition is met;

the auxiliary motor control unit is further used for receiving and executing the gear shifting assisting instruction so as to control the auxiliary motor to output torque to the engine and accelerate gear shifting of the transmission;

wherein, work as whole car the control unit with between the vice motor control unit whole car the control unit with between the engine control unit with whole car the control unit with the communication is normal just between the derailleur the vice motor with when vice motor control unit does not break down, whole car the control unit is in hybrid vehicle accelerates with speed just when the rotational speed of engine is greater than first predetermined rotational speed, judges to satisfy and assists the condition of upshifting, and hybrid vehicle decelerates just when the rotational speed of engine is less than the second predetermined rotational speed, judges to satisfy and assists the condition of downshifting.

6. The shift control system of a hybrid electric vehicle according to claim 5, wherein the vehicle control unit generates a supplementary upshift instruction when it is determined that the supplementary upshift condition is satisfied, and sends the supplementary upshift instruction to the sub-motor control unit, and the sub-motor control unit is configured to receive and execute the supplementary upshift instruction to control the sub-motor to output a negative torque to the engine until the rotation speed of the engine is reduced to a first target rotation speed.

7. The shift control system of a hybrid electric vehicle according to claim 5, wherein the vehicle control unit generates an assist downshift instruction when determining that the assist downshift condition is satisfied, and sends the assist downshift instruction to the auxiliary motor control unit, and the auxiliary motor control unit is configured to receive and execute the assist downshift instruction to control the auxiliary motor to output a positive torque to the engine until the rotation speed of the engine is increased to a second target rotation speed.

8. A hybrid vehicle characterized by comprising the shift control system of a hybrid vehicle according to any one of claims 5 to 7.