阅读说明：本技术 混动车辆发动机启动控制方法、系统及混动车辆 (Hybrid vehicle engine starting control method and system and hybrid vehicle ) 是由 徐洋 刘洋 马海涛 尹亿光 杨俊超 于 2020-07-14 设计创作，主要内容包括：本发明提供一种混动车辆发动机启动控制方法、系统及混动车辆,涉及车辆领域。该方法包括：在处于纯电驱动模式,确定需要启动发动机的情况下：获取三元催化器的温度；确定所述温度是否低于起燃温度；在确定所述温度低于起燃温度的情况下,控制发动机启动并进入高怠速工况,在所述温度达到起燃温度的情况下,控制发动机参与驱动；或在处于油电混合驱动模式,确定需要停用发动机的情况下：获取发动机冷却液温度；确定发动机冷却液温度是否大于设定温度；在确定发动机冷却液温度不大于设定温度的情况下,控制发动机进入低怠速工况,并在发动机冷却液温度大于设定温度时,停用发动机。避免发动机冷机状态下直接输出扭矩导致发动机损伤的问题。(The invention provides a hybrid vehicle engine starting control method and system and a hybrid vehicle, and relates to the field of vehicles. The method comprises the following steps: in the case of determining that the engine needs to be started in the pure electric drive mode: acquiring the temperature of the three-way catalyst; determining whether the temperature is below a light-off temperature; under the condition that the temperature is lower than the ignition temperature, controlling the engine to start and enter a high idle speed working condition, and under the condition that the temperature reaches the ignition temperature, controlling the engine to participate in driving; or in the case of determining that the engine needs to be stopped in the hybrid oil-electric driving mode: obtaining the temperature of engine coolant; determining whether an engine coolant temperature is greater than a set temperature; and under the condition that the temperature of the engine coolant is determined not to be greater than the set temperature, controlling the engine to enter a low-idle working condition, and when the temperature of the engine coolant is greater than the set temperature, stopping the engine. The problem that the engine is damaged due to the fact that torque is directly output under the cold state of the engine is avoided.)

1. A hybrid vehicle engine start control method, characterized by comprising:

in the case where the hybrid vehicle is in an electric-only drive mode, it is determined that the engine needs to be started, performing the following operations:

acquiring the temperature of the three-way catalyst;

determining whether a temperature of the three-way catalyst is lower than a light-off temperature; and

under the condition that the temperature of the three-way catalyst is determined to be lower than the ignition temperature, controlling the engine to start and enter a high-idle speed working condition, and under the condition that the temperature of the three-way catalyst reaches the ignition temperature, controlling the engine to participate in driving; or

In the case where the hybrid vehicle is in a hybrid drive mode, it is determined that the engine needs to be deactivated, performing the following operations:

obtaining the temperature of engine coolant;

determining whether the engine coolant temperature is greater than a set temperature; and

controlling the engine to enter a low idle condition if it is determined that the engine coolant temperature is not greater than the set temperature, and deactivating the engine if the engine coolant temperature is greater than the set temperature.

2. The method of claim 1, wherein the determining that an engine start is required comprises:

acquiring a vehicle torque demand; and

determining that the engine needs to be started if the vehicle torque request is greater than an upper torque threshold limit of the electric-only drive mode.

3. The method of claim 1, wherein said determining that deactivation of the engine is required comprises:

acquiring a vehicle torque demand; and

determining that the engine needs to be deactivated if the vehicle torque request is less than a lower torque threshold limit of the hybrid electric-gasoline drive mode; and/or

In the event that a braking signal is obtained, it is determined that the engine needs to be deactivated.

4. The method of claim 2, further comprising:

after the engine is controlled to participate in driving, distributing torque to the engine according to the vehicle torque demand so as to enter the oil-electric hybrid driving mode.

5. A hybrid vehicle engine start control system characterized by comprising a control apparatus that includes a controller and an acquisition unit connected to each other, the acquisition unit being configured to acquire a temperature of a three-way catalyst and/or an engine coolant temperature, the controller being configured to perform the following operations in accordance with the temperature of the three-way catalyst and/or the engine coolant temperature acquired by the acquisition unit:

when the hybrid vehicle is in a pure electric driving mode and the engine needs to be started, determining whether the temperature of the three-way catalyst is lower than a light-off temperature or not, controlling the engine to start and enter a high-idle speed working condition under the condition that the temperature of the three-way catalyst is lower than the light-off temperature, and controlling the engine to participate in driving under the condition that the temperature of the three-way catalyst reaches the light-off temperature; or

The method includes the steps of determining whether the engine coolant temperature is greater than a set temperature in the case where the hybrid vehicle is in a hybrid electric drive mode, determining that the engine needs to be deactivated, controlling the engine to enter a low idle condition in the case where it is determined that the engine coolant temperature is not greater than the set temperature, and deactivating the engine in the case where the engine coolant temperature is greater than the set temperature.

6. The system of claim 5, wherein the determining that an engine start is required comprises:

the acquisition unit acquires a vehicle torque demand; and

the controller determines that the engine needs to be started upon determining that the vehicle torque request is greater than an upper torque threshold limit of the electric-only drive mode.

7. The system of claim 5, wherein the determining that the engine needs to be deactivated comprises:

the acquisition unit acquires the vehicle torque demand; and

the controller determines that the engine needs to be deactivated if it is determined that the vehicle torque request is less than a lower torque threshold limit of the hybrid electric-gasoline drive mode; and/or

In the event that a braking signal is obtained, it is determined that the engine needs to be deactivated.

8. The system of claim 6, wherein the controller is further configured to:

after the engine is controlled to participate in driving, distributing torque to the engine according to the vehicle torque demand so as to enter the oil-electric hybrid driving mode.

9. The system of any one of claims 5-8, wherein the controller comprises: vehicle control unit VCU and driving computer ECU.

10. A hybrid vehicle characterized by comprising the hybrid vehicle engine start control system according to any one of claims 5 to 9.

Technical Field

The invention relates to the field of vehicles, in particular to a hybrid vehicle and an engine starting control method and system thereof.

Background

In the process of one-time running of a hybrid electric vehicle (also called a hybrid electric vehicle), the situation that the torque demand of the vehicle is increased and an engine is required to be started to participate in driving after the hybrid electric vehicle starts to run in an electric pure mode for a period of time or continuously runs in the electric pure mode for a long time may occur. Because the engine does not work for a long time and is still in a cold state, if the engine is directly started and participates in driving, the oil consumption is quite high, and meanwhile, the emission of pollutants is increased because the temperature of the three-way catalyst is lower than the ignition temperature; in addition, when the engine is started in a cold state and directly outputs torque, the structure thereof may be damaged.

Disclosure of Invention

The invention aims to provide a hybrid vehicle engine starting control method, a system and a hybrid vehicle, wherein in an electric drive mode, when an engine receives a starting request, the engine does not immediately participate in driving, the temperature of a three-way catalyst is monitored at first, if the temperature is lower than the ignition temperature of the three-way catalyst, the three-way catalyst enters a high-idle working condition, the ignition temperature is quickly established, and then the engine is started; and/or in the oil-electric hybrid driving mode, when the engine receives a stop request, the engine does not stop driving immediately, the engine cooling liquid temperature is monitored firstly, if the engine cooling liquid temperature is not higher than the set temperature, the low-idling condition is entered, and the engine is stopped after the cooling liquid temperature is higher than the set temperature. By the scheme, the problem that the engine is damaged due to the fact that torque is directly output under the cold state of the engine can be avoided or the engine can be ensured to be in a normal working temperature range when being started next time, so that oil consumption is reduced, and emission is reduced.

In order to achieve the above object, an embodiment of the present invention provides a hybrid vehicle engine start control method, including: in the case where the hybrid vehicle is in an electric-only drive mode, it is determined that the engine needs to be started, performing the following operations: acquiring the temperature of the three-way catalyst; determining whether a temperature of the three-way catalyst is lower than a light-off temperature; under the condition that the temperature of the three-way catalyst is determined to be lower than the ignition temperature, the engine is controlled to be started and enters a high-idle-speed working condition, and under the condition that the temperature of the three-way catalyst reaches the ignition temperature, the engine is controlled to participate in driving; or in the case where the hybrid vehicle is in a hybrid electric-fuel driving mode, it is determined that the engine needs to be deactivated, performing the following operations: obtaining the temperature of engine coolant; determining whether the engine coolant temperature is greater than a set temperature; and controlling the engine to enter a low idle condition under the condition that the temperature of the engine coolant is determined not to be greater than the set temperature, and stopping the engine under the condition that the temperature of the engine coolant is greater than the set temperature.

Optionally, the determining that the engine needs to be started comprises: acquiring a vehicle torque demand; and determining that the engine needs to be started if the vehicle torque request is greater than an upper torque threshold limit of the electric-only drive mode.

Optionally, the determining that the engine needs to be deactivated includes: acquiring a vehicle torque demand; and determining that the engine needs to be deactivated if the vehicle torque request is less than a lower torque threshold limit of the hybrid electric-gasoline drive mode; and/or determining that the engine needs to be deactivated if a braking signal is obtained.

Optionally, the method further includes: after the engine is controlled to participate in driving, distributing torque to the engine according to the vehicle torque demand so as to enter the oil-electric hybrid driving mode.

An embodiment of the present invention also provides a hybrid vehicle engine start control system, including a control apparatus that includes a controller and an acquisition unit connected to each other, the acquisition unit being configured to acquire a temperature of a three-way catalyst and/or an engine coolant temperature, the controller being configured to perform the following operations according to the temperature of the three-way catalyst and/or the engine coolant temperature acquired by the acquisition unit: when the hybrid vehicle is in a pure electric driving mode and the engine needs to be started, determining whether the temperature of the three-way catalyst is lower than a light-off temperature or not, controlling the engine to start and enter a high-idle speed working condition under the condition that the temperature of the three-way catalyst is lower than the light-off temperature, and controlling the engine to participate in driving under the condition that the temperature of the three-way catalyst reaches the light-off temperature; or determining whether the temperature of the engine coolant is greater than a set temperature under the condition that the temperature of the engine coolant is determined to be not greater than the set temperature when the hybrid vehicle is in a gasoline-electric hybrid driving mode and the engine needs to be stopped, controlling the engine to enter a low idle condition under the condition that the temperature of the engine coolant is determined to be not greater than the set temperature, and stopping the engine under the condition that the temperature of the engine coolant is greater than the set temperature.

Optionally, the determining that the engine needs to be started comprises: the acquisition unit acquires a vehicle torque demand; and the controller determines that the engine needs to be started if it is determined that the vehicle torque request is greater than an upper torque threshold limit of the electric-only drive mode.

Optionally, the determining that the engine needs to be deactivated includes: the acquisition unit acquires the vehicle torque demand; and the controller determining that the engine needs to be deactivated if it is determined that the vehicle torque request is less than a lower torque threshold limit of the hybrid electric-gasoline drive mode; and/or determining that the engine needs to be deactivated if a braking signal is obtained.

Optionally, the controller is further configured to: after the engine is controlled to participate in driving, distributing torque to the engine according to the vehicle torque demand so as to enter the oil-electric hybrid driving mode.

Optionally, the controller includes: vehicle control unit VCU and driving computer ECU.

The embodiment of the invention also provides a hybrid vehicle which comprises the engine starting control system of the hybrid vehicle.

According to the technical scheme, in the pure electric driving mode, when the engine receives a starting request, the engine does not immediately participate in driving, the temperature of the three-way catalyst is monitored at first, if the temperature is lower than the ignition temperature of the three-way catalyst, the high-idle speed working condition is entered, the ignition temperature is quickly established, and then the engine is started; and/or in the oil-electric hybrid driving mode, when the engine receives a stop request, the engine does not stop driving immediately, the engine cooling liquid temperature is monitored firstly, if the engine cooling liquid temperature is not higher than the set temperature, the low-idling condition is entered, and the engine is stopped after the cooling liquid temperature is higher than the set temperature. By the scheme, the problem that the engine is damaged due to the fact that torque is directly output under the cold state of the engine can be avoided or the engine can be ensured to be in a normal working temperature range when being started next time, so that oil consumption is reduced, and emission is reduced.

Additional features and advantages of embodiments of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the embodiments of the invention without limiting the embodiments of the invention. In the drawings:

FIG. 1 is a schematic diagram of a P2.5 configuration hybrid vehicle powertrain;

FIG. 2 is a schematic flow chart illustrating a method for controlling engine start of a hybrid vehicle according to an embodiment of the present invention;

FIG. 3 is a flowchart illustrating a method for controlling engine start of a hybrid vehicle according to a second embodiment of the present invention;

FIG. 4 is a schematic flow chart illustrating a method for controlling engine start of a hybrid vehicle according to a third embodiment of the present invention;

fig. 5 is a schematic structural diagram of an engine start control system of a hybrid vehicle according to an embodiment of the present invention.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating embodiments of the invention, are given by way of illustration and explanation only, not limitation.

The invention provides a method for controlling the starting of an engine of a hybrid vehicle, wherein in a pure electric driving mode, when the engine receives a starting request, the engine does not immediately participate in driving, but the temperature of a three-way catalyst is monitored at first, if the temperature is lower than the ignition temperature of the three-way catalyst, the high-idle working condition is entered, the ignition temperature is quickly established, and then the engine is started and participates in normal driving; when the torque demand is reduced and the vehicle is switched to pure electric drive again, whether the temperature of the engine coolant is in a normal working temperature range or not is judged, and the engine is stopped and fuel cut off or enters a low-idle working condition for warming up until the temperature is higher than a certain threshold value.

The embodiment of the invention aims at the design of a hybrid electric vehicle with a P2.5 configuration, and FIG. 1 shows a schematic structural diagram of a power system of the hybrid electric vehicle with the P2.5 configuration. Without being limited thereto, the embodiment of the invention may also be applied to a hybrid vehicle having at least one engine and one motor, and the transmission relationship between the engine and the motor is decoupled. The invention can reduce the working time of the engine under severe conditions, further reduce the oil consumption of the engine and reduce the emission of pollutants by coordinately controlling the temperature value of the engine coolant for starting and stopping the engine under the above conditions.