CN116442980A

CN116442980A - Method and system for controlling start and stop of engine of hybrid electric vehicle

Info

Publication number: CN116442980A
Application number: CN202310310365.3A
Authority: CN
Inventors: 伍庆龙
Original assignee: FAW Group Corp
Current assignee: FAW Group Corp
Priority date: 2023-03-27
Filing date: 2023-03-27
Publication date: 2023-07-18

Abstract

The embodiment of the invention discloses a start-stop control method and a start-stop control system for an engine of a hybrid electric vehicle. The method is applied to a vehicle controller and comprises the following steps: receiving control parameter information transmitted by at least two controllers in a target vehicle; determining start-stop control conditions of an engine in a target vehicle based on the control parameter information; and controlling the engine to start and stop according to at least two start and stop control conditions and the preset start and stop priority level. According to the embodiment of the invention, the start-stop control conditions of the engine in the target vehicle are respectively determined through the control parameter information transmitted by the at least two controllers, and the engine is controlled to start and stop according to the at least two start-stop control conditions and the preset start-stop priority level, so that the time for controlling the engine to start can be more effectively identified from multiple aspects, the reasonable control of the start and stop of the engine under different conditions is realized, the stability and the reliability in the running process of the vehicle are ensured, and better vehicle performance is provided for users.

Description

Method and system for controlling start and stop of engine of hybrid electric vehicle

Technical Field

The invention relates to the technical field of vehicles, in particular to a start-stop control method and system for an engine of a hybrid electric vehicle.

Background

Because the power system configuration scheme of the hybrid power vehicle is different from that of the traditional vehicle, the starting and stopping of the engine are controlled based on the power performance, the drivability, the economy and the like, besides taking the starting condition of the vehicle into consideration, the starting and stopping of the engine are controlled based on the purpose of improving the performance of the hybrid power, and if the starting of the engine cannot be controlled effectively, the performance of the whole vehicle is influenced, and the drivability, the comfort, the fuel economy and the like are influenced. How to formulate an effective start-up strategy and control engine start-up and stop is one of the key problems to be solved at present.

In the prior art, in the engine start-stop control, the basis for judging the engine start-up mainly comprises the engine working state and other vehicle related information (such as the opening of an air conditioner), such as: the working conditions of start and stop are determined according to the water temperature of the engine and two dimensions of the storage battery, multiple aspects are not considered for effectively controlling the start and stop of the engine, and the influence of the start and stop triggering function on the running of the vehicle under different working conditions is not considered, so that the stability and the reliability of the running process of the vehicle cannot be ensured.

Disclosure of Invention

In view of the above, the invention provides a method and a system for controlling the start and stop of an engine of a hybrid electric vehicle, which can more effectively identify when to control the start of the engine from multiple aspects, realize reasonable control of the start and stop of the engine under different conditions, and ensure the stability and reliability of the vehicle in the running process, thereby providing better vehicle performance for users.

According to an aspect of the present invention, an embodiment of the present invention provides a method for controlling start and stop of an engine of a hybrid vehicle, which is applied to a vehicle controller, and includes:

receiving control parameter information transmitted by at least two controllers in a target vehicle;

determining start-stop control conditions of an engine in the target vehicle based on each of the control parameter information, respectively;

and controlling the engine to start and stop according to at least two start and stop control conditions and a preset start and stop priority level.

According to another aspect of the present invention, there is provided a system for controlling start and stop of an engine of a hybrid vehicle, the system including: the system comprises an engine, a motor and a whole vehicle controller;

the engine is connected with the whole vehicle controller and the motor and is used for generating engine starting power and engine water temperature, sending the engine starting power and the engine water temperature to the whole vehicle controller and executing starting or stopping operation under the condition that the starting and stopping control conditions are met;

the motor is connected with the whole vehicle controller and the engine, and is used for generating motor required torque, starting reserved torque, motor available charging/discharging power, starting reserved charging/discharging power and motor rotating speed, and driving the engine to start when the starting operation of the engine is met;

The whole vehicle controller is connected with the motor and the engine and is used for executing any method of the embodiment of the invention.

According to the technical scheme provided by the embodiment of the invention, the start-stop control conditions of the engine in the target vehicle are respectively determined through the control parameter information transmitted by the at least two controllers, and the engine is controlled to start and stop according to the at least two start-stop control conditions and the preset start-stop priority level, so that the time of starting the engine can be more effectively identified from multiple aspects, the reasonable control of the start and stop of the engine under different conditions is realized, the stability and the reliability in the running process of the vehicle are ensured, and better vehicle performance is provided for users.

It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the invention or to delineate the scope of the invention. Other features of the present invention will become apparent from the description that follows.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a flow chart of a method for controlling start and stop of an engine of a hybrid vehicle according to an embodiment of the present invention;

FIG. 2 is a flow chart of determining start-stop control conditions of an engine in a hybrid vehicle engine start-stop control method according to an embodiment of the present invention;

FIG. 3 is a flow chart of yet another method for controlling engine start and stop of a hybrid vehicle according to an embodiment of the present invention;

FIG. 4 is a flowchart of yet another method for controlling start and stop of an engine of a hybrid vehicle according to an embodiment of the present invention;

FIG. 5 is a schematic diagram illustrating a control process of starting a motor-driven engine according to an embodiment of the present invention;

FIG. 6 is a block diagram illustrating a hybrid vehicle engine start-stop control system according to an embodiment of the present invention;

fig. 7 is a block diagram illustrating a structure of an engine start-stop control system for a hybrid vehicle according to an embodiment of the present invention.

Detailed Description

In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

In an embodiment, fig. 1 is a flowchart of a method for controlling start and stop of an engine of a hybrid vehicle according to an embodiment of the present invention, where the method may be performed by a hybrid vehicle engine start and stop control system, and the hybrid vehicle engine start and stop control system may be implemented in hardware and/or software.

As shown in fig. 1, the method specifically includes the steps of:

s110, receiving control parameter information transmitted by at least two controllers in the target vehicle.

The control parameter information is understood to be related parameter information that can control the engine to perform start-stop operations. The control parameter information may be obtained by controllers in two or more vehicles.

In some embodiments, the control parameter information may include at least motor allowable torque, reserved torque when the motor is on-coming, motor available charge power, motor available discharge power, motor on-coming reserved charge power, motor on-coming reserved discharge power, motor speed, motor target speed, engine on-coming power, vehicle wheel end torque value, driving mode, engine water temperature, gearbox oil temperature, state of charge of the high voltage battery, temperature of the high voltage battery, battery on-coming temperature, and vehicle speed. Of course, the different control parameter information may be acquired in the same controller or may be acquired in a different controller.

In this embodiment, different parameter information may be obtained from the battery management system, the motor controller, the vehicle body electronic stability system, the gearbox controller, and the engine controller, respectively, to form control parameter information; in some embodiments, the acceleration demand power may also be detected from an acceleration position sensor during the engine start determination, and the power of the engine start while the motor is running, etc. may be determined in the hybrid controller to collectively constitute the control parameter information. Specifically, the state of charge, the battery temperature, the battery starting temperature and the electric quantity mode of the power battery can be obtained from the battery management system; the motor allowable torque, the motor starting reserved torque, the motor available charging power, the motor available discharging power, the motor starting reserved charging power, the motor starting reserved discharging power, the current rotating speed of the motor and the target rotating speed of the motor can be obtained from the motor controller; the current speed of the target vehicle can also be obtained from the vehicle body electronic stability system; the gearbox oil temperature may also be obtained from a gearbox controller; engine start power, engine water temperature, etc. of the engine may also be obtained from the engine controller, and the embodiment is not limited herein.

S120, starting and stopping control conditions of the engine in the target vehicle are respectively determined based on the control parameter information.

The start-stop control condition refers to a control condition related to start-stop operation of the engine in the target vehicle. Of course, the start-stop control conditions of the engine may include two or more, and the start-stop operation of the engine may be controlled in accordance with the start-stop control conditions.

In this embodiment, the start control conditions of the engine may be various start-stop control conditions, and may include, but not limited to, a dynamic start trigger control condition, a driving start trigger control condition, an economical start trigger control condition, a component warm-up start trigger control condition, a high-voltage battery start trigger control condition, a vehicle safety start trigger control condition, an external other start trigger control, and a stop trigger control condition in each corresponding case.

In this embodiment, the start-stop control condition of the engine in the target vehicle may be determined by the control parameter information respectively corresponding to the engine, the motor, the battery, the gearbox, the driving mode and the whole vehicle information acquired by the same or different controllers; in some embodiments, the dynamic start-stop control condition of the engine can also be determined by the wheel end required torque, the motor allowable torque and the motor start-stop reserved torque; determining driving start-stop control conditions of an engine according to available charging power of a motor, reserved charging power of a motor starting machine, electric quantity mode, available discharging power of the motor, available starting power of an engine and available conditions of a starter, and a vehicle wheel end torque value generated by a user stepping on an accelerator pedal of a target vehicle and a preset wheel end standard value and a driving mode when the target vehicle is in a sliding or braking process; determining partial warm-up start-stop control conditions of the engine according to an electric quantity maintenance mode of a target vehicle, vehicle required power, engine starting power, engine water temperature, gearbox oil temperature and preset oil temperature standard values; determining a power battery start-stop control condition of the engine according to the state of charge of the power battery, a preset battery lower limit value, a preset battery upper limit value, the temperature of the power battery and the battery start-stop temperature; determining a safe start-stop control condition of the vehicle of the engine according to the current vehicle speed, a preset vehicle speed threshold value, the current rotating speed of the motor and a preset rotating speed threshold value; in the state where the vehicle is in the diagnostic service, other external start-stop control of the engine is determined, and the like, the embodiment is not limited herein.

S130, controlling the engine to start and stop according to at least two start and stop control conditions and a preset start and stop priority level.

The preset start-stop priority level refers to a priority level of the engine for start-stop control, and the priority level can be preset manually.

In this embodiment, the grading of the priority may include receiving an engine stop signal sent by the gearbox controller or the engine controller, sending an engine stop request signal to the engine controller, and controlling the engine to perform a stop operation, which is the first priority; receiving an engine starting signal sent by a gearbox controller or an engine controller, sending an engine starting request signal to the engine controller, and controlling the engine to start, wherein the engine starting operation is the second priority; any one of the start-stop control conditions is the third priority. It will be appreciated that engine start-stop control requires a systematic diagnosis that corresponds to a first, i.e., highest, priority.

In this embodiment, the start-stop action sequence of the engine may be determined according to a preset priority level, the first priority, the second priority and the third priority may be sequentially determined, and corresponding operations may be executed according to the determination result. In some embodiments, if the preset priority level is the first priority level, sending an engine stop request signal to an engine controller to control the engine to perform stop operation; if the preset priority level is not the first priority level, continuously judging whether the priority level is the second priority level, if the priority level is the second priority level, sending an engine starting request signal to an engine controller to control the engine to start the engine, and if the priority level is not the second priority level, continuously judging whether the priority level is the third priority level, and if the priority level is the third priority level, controlling the engine to start and stop according to each start and stop control condition; in some embodiments, the basic information of the vehicle and the external information of the vehicle may be used to start the engine when the engine is in the off state, if the basic information of the vehicle satisfies the starting condition of the engine and the external information of the vehicle satisfies the starting condition of the engine; if the basic information of the vehicle does not meet the starting condition of the engine and the external information of the vehicle does not meet the starting condition of the engine, the engine is continuously turned off.

In some embodiments, the preset start-stop priority level classification includes: the first priority, the second priority and the third priority, wherein the first priority is greater than the second priority, and the second priority is greater than the third priority;

wherein the first priority comprises: receiving an engine stop signal sent by a gearbox controller or an engine controller, sending an engine stop request signal to the engine controller, and controlling the engine to stop;

the second priority includes: receiving an engine starting signal sent by a gearbox controller or an engine controller, sending an engine starting request signal to the engine controller, and controlling the engine to start;

The third priority includes: any one of the start-stop control conditions.

In this embodiment, the division of the preset start-stop priority level may include a first priority, a second priority and a third priority, where the first priority is the highest priority, the second priority is the second priority, and the third priority is the lowest priority, that is, the first priority is greater than the second priority, and the second priority is greater than the third priority. In this embodiment, the first priority is that an engine stop signal sent by the gearbox controller or the engine controller is received, an engine stop request signal is sent to the engine controller, and the engine is controlled to perform stop operation; the second priority is that an engine starting signal sent by a gearbox controller or an engine controller is received, an engine starting request signal is sent to the engine controller, and the engine is controlled to start; the third priority includes: any one of the start-stop control conditions is considered from the importance and the safety in the embodiment to set the priority level, so that the reliability of the running of the vehicle is ensured.

Illustratively, the priority is highest: when a gearbox controller in a power system sends a clutch signal C0 OpenReq=1, or an engine signal EngStopReq=1 sent by an engine controller, or an engine signal EngStaInhb=1 sent by the engine controller, if the whole vehicle controller receives one signal, an engine starting request signal=0 is sent to the engine controller, and the engine is controlled to stop; priority order: when a gearbox controller in a power system sends a clutch signal C0 OpenInhb=1 or an engine signal EngStaReq=1 sent by an engine controller, if the whole vehicle controller receives one signal, an engine starting request signal=1 is sent to the engine controller, and engine starting is controlled; the priority is back: each start-stop function control is that when a start-stop or stop request in any start-stop control occurs, the whole vehicle controller controls the start-stop or stop of the engine.

In an embodiment, fig. 2 is a flowchart of determining a start-stop control condition of an engine in a hybrid vehicle engine start-stop control method according to an embodiment of the present invention, where control parameter information transmitted by at least two controllers in a target vehicle is received based on the above embodiments, and the start-stop control condition of the engine in the target vehicle is determined based on the control parameter information, respectively, is further refined.

As shown in fig. 2, the method for controlling start and stop of the engine of the hybrid vehicle in the present embodiment may specifically include the following steps:

s210, acquiring the state of charge, the battery temperature, the battery starting temperature and the electric quantity mode of the power battery from the battery management system.

The power mode refers to a power mode of a power battery in a vehicle, and the power mode may include a power maintenance mode and a power consumption mode.

In this embodiment, the state of charge corresponding to the power battery, the current temperature of the battery, the corresponding temperature of the motor in starting and stopping operation, and the electric quantity mode of the power battery in the vehicle may be collected from the battery management system, so as to determine the start and stop control conditions corresponding to the engine according to the state of charge of the power battery, the comparison between the preset battery lower limit value and the preset battery upper limit value, the comparison between the temperature of the power battery and the preset battery starting and stopping temperature threshold value, and the electric quantity mode of the power battery in the vehicle, respectively. In this embodiment, the state of charge corresponding to the power battery may be tested by the sensor.

S220, acquiring motor allowable torque, motor starting reserved torque, motor available charging power, motor available discharging power, motor starting reserved charging power, motor starting reserved discharging power, motor current rotating speed and motor target rotating speed from a motor controller.

The current rotating speed of the motor is the corresponding rotating speed of the motor in the running process of the vehicle, and the motor can be tested through the sensor.

In this embodiment, the motor allowable torque, the motor start-up reserved torque, the motor available charging power, the motor available discharging power, the motor start-up reserved charging power, the motor start-up reserved discharging power, the current rotation speed of the motor and the target rotation speed of the motor may be obtained from the motor controller, so as to determine the start-stop control condition corresponding to the engine according to the comparison between the motor allowable torque and the motor start-up reserved torque, the comparison between the motor available charging power and the motor start-up reserved charging power, the motor available discharging power, the engine start-up power and the available condition of the starter, and the current rotation speed and the preset rotation speed threshold value of the motor.

S230, acquiring the current speed of the target vehicle from the vehicle body electronic stability system.

The current vehicle speed refers to a vehicle speed in the running process of the vehicle.

In this embodiment, the current vehicle speed of the target vehicle in the running process may be obtained from the vehicle body electronic stability system, and it should be noted that, when the current vehicle speed reaches a certain threshold, an engine start request signal may be triggered to control the engine start; and under the condition that the current vehicle speed is smaller than a certain threshold value, triggering an engine stop request signal to control the engine to stop.

S240, acquiring the oil temperature of the gearbox from the gearbox controller.

In this embodiment, during the running of the vehicle, the oil temperature of the gearbox changes, and the oil temperature corresponding to the gearbox can be measured by the sensor and obtained from the gearbox controller.

S250, acquiring engine starting power and engine water temperature of the engine from an engine controller.

In the present embodiment, the water temperature of the engine, the corresponding power of the engine when the engine starts up, and the engine water temperature may be detected by a sensor mounted on the vehicle, and the engine power may be obtained from the engine controller.

And S260, acquiring a wheel end required torque when a user steps on a target vehicle pedal, and determining a first start-stop control condition of the engine according to the wheel end required torque, the motor allowable torque and the motor start-up reserved torque.

Wherein the first start-stop control condition is a dynamic start-stop control condition.

In this embodiment, the user may generate a wheel end demand torque when stepping on the target vehicle pedal, so that the first start-stop control condition of the engine may be determined by the wheel end demand torque, the motor allowable torque and the motor start-up reserve torque acquired from the motor controller, and specifically, if the wheel end demand torque is greater than or equal to a difference between the motor allowable torque and the motor start-up reserve torque in a preset period of time, an engine start request signal is sent to the engine controller to control the engine start; and in a preset time period, if the required torque of the wheel end is smaller than the difference value among the allowable torque of the motor, the reserved torque of the starting machine of the motor and the preset first regulating value, sending an engine starting and stopping request signal to an engine controller, and controlling the engine to stop.

And S270, determining a second start-stop control condition of the engine according to the available charging power of the motor, the reserved charging power of the starting machine of the motor and the electric quantity mode.

In this embodiment, the second start-stop control condition of the engine may be determined according to the available charging power of the motor, the reserved charging power of the motor start-up and the electric quantity mode, specifically, when the current electric quantity maintenance mode is detected, and the available charging power of the motor is smaller than the reserved charging power of the motor start-up, an engine start-up request signal is sent to the engine controller to control the engine start-up; and when detecting that the current power consumption mode exists or the available charging power of the motor is larger than or equal to the reserved charging power of the starting machine of the motor and a preset second regulating value, sending an engine starting and stopping request signal to an engine controller to control the stopping of the engine.

And S280, determining a third start-stop control condition according to the available discharge power of the motor, the available start-up power of the engine and whether the starter is available.

In this embodiment, the third start-stop control condition may be determined according to the available discharge power of the motor, the start-up power of the engine, and whether the starter is available. Specifically, detecting that the starter is unavailable due to failure or that the available discharge power of the motor is smaller than or equal to the difference value between the engine starting power and a preset third regulating value, sending an engine starting request signal to an engine controller, and controlling the engine to start; and detecting that the starter is normally available, or that the available discharge power of the motor is larger than the sum of the starting power of the engine and a preset third regulating value, sending an engine starting and stopping request signal to an engine controller, and controlling the engine to stop.

S290, receiving a vehicle wheel end torque value generated by a user stepping on an accelerator pedal of the target vehicle when the target vehicle is in a sliding or braking process, and determining a fourth start-stop control condition of the engine according to the vehicle wheel end torque value and a preset wheel end standard value.

In this embodiment, during a sliding or braking process of the target vehicle, a vehicle wheel end torque value generated by a user stepping on an accelerator pedal of the target vehicle is received, and a fourth start-stop control condition of the engine is determined according to the vehicle wheel end torque value and a preset wheel end standard value. Specifically, in a preset time period, if the torque value of the wheel end of the vehicle generated by stepping on the accelerator pedal is detected to be larger than or equal to a preset wheel end standard value, an engine starting request signal is sent to an engine controller, and engine starting is controlled; and in a preset time period, if the torque value of the wheel end of the vehicle is smaller than the standard value of the preset wheel end, sending an engine start-stop request signal to an engine controller, and controlling the engine to stop.

S2100, determining a fifth start-stop control condition according to a driving mode of the target vehicle.

Wherein the second start-stop control condition, the third start-stop control condition, the fourth start-stop control condition, and the fifth start-stop control condition are driving start-stop control conditions.

In the present embodiment, the fifth start-stop control condition may be determined in accordance with the driving mode of the target vehicle. Specifically, the current driving mode is detected to be a motion mode, an engine starting request signal is sent to an engine controller, and engine starting is controlled.

S2110, detecting that the target vehicle is in a power maintenance mode, and determining a sixth start-stop control condition of the engine according to the vehicle demand power and the engine start-stop power of the target vehicle.

The sixth start-stop control condition is an economical start-stop control condition.

In this embodiment, when it is detected that the target vehicle is in the electric quantity maintenance mode, a sixth start-stop control condition of the engine may be determined according to the vehicle required power and the engine start-up power of the target vehicle, and specifically, when it is detected that the vehicle is in the electric quantity maintenance mode and the vehicle required power of the target vehicle is greater than or equal to the engine start-up power in a preset time period, an engine start-up request signal is sent to the engine controller to control the engine start-up; the method comprises the steps of detecting that a vehicle is in an electric quantity maintaining mode, and in a preset time period, sending an engine start-stop request signal to an engine controller to control the engine to stop, wherein the vehicle required power is smaller than the difference value between the engine start-up power and a preset fourth regulating value.

S2120, determining a seventh start-stop control condition of the engine according to the water temperature of the engine and a preset engine temperature standard value.

In this embodiment, a seventh start-stop control condition of the engine may be determined according to the engine water temperature and a preset engine temperature standard value, and specifically, if the engine water temperature is less than or equal to the preset engine temperature standard value, an engine start request signal is sent to the engine controller to control the engine start; and when the temperature of the engine water is larger than a preset engine temperature standard value, sending an engine start-stop request signal to an engine controller according to control requirements, and controlling the engine to stop.

S2130, determining an eighth start-stop control condition of the engine according to the oil temperature of the gearbox and a preset oil temperature standard value.

Wherein the seventh start-stop control condition and the eighth start-stop control condition are partial warm-up start-stop control conditions. In this embodiment, the eighth start-stop control condition of the engine may be determined according to the gearbox oil temperature and a preset oil temperature standard value, and specifically, if the gearbox oil temperature is less than or equal to the preset oil temperature standard value, an engine start request signal is sent to the engine controller to control the engine start; and under the condition that the oil temperature of the gearbox is larger than a preset oil temperature standard value, sending an engine start-stop request signal to an engine controller according to control requirements, and controlling the engine to stop.

S2140, a ninth start-stop control condition of the engine is determined according to the state of charge of the power battery, the preset battery lower limit value and the preset battery upper limit value.

In the present embodiment, the ninth start-stop control condition of the engine may be determined in accordance with the state of charge of the power battery, the preset battery lower limit value, and the preset battery upper limit value. Specifically, when the state of charge of the power battery is smaller than or equal to a preset battery lower limit value, an engine starting request signal is sent to an engine controller, and engine starting is controlled; and when the charge state of the power battery is larger than the preset battery upper limit value, sending an engine start-stop request signal to an engine controller, and controlling the engine to stop.

And S2150, determining a tenth start-stop control condition of the engine according to the temperature of the high-voltage battery and the battery start-up temperature when the temperature of the power battery reaches the preset battery start-up temperature threshold.

The ninth start-stop control condition and the tenth start-stop control condition are power battery start-stop control conditions.

In this embodiment, when the temperature of the power battery is detected to reach the preset battery start-up temperature threshold, the tenth start-stop control condition of the engine may be determined according to the temperature of the high-voltage battery and the battery start-up temperature. Specifically, when the temperature of the high-voltage battery reaching the preset battery temperature threshold is smaller than the difference between the preset battery starting temperature threshold and the preset fifth regulating value, an engine starting request signal is sent to an engine controller, and the engine starting is controlled; and when the temperature of the high-voltage battery reaching the preset battery temperature threshold is greater than or equal to the preset battery starting temperature threshold, controlling the engine to start by using the starter.

S2160, determining an eleventh start-stop control condition of the engine according to the current vehicle speed and a preset vehicle speed threshold.

In the present embodiment, the eleventh start-stop control condition of the engine may be determined in accordance with the current vehicle speed and the preset vehicle speed threshold. Specifically, when the current vehicle speed is greater than or equal to a preset first vehicle speed threshold, an engine starting request signal is sent to an engine controller, and engine starting is controlled; when the current vehicle speed is smaller than a preset second vehicle speed threshold, stopping the engine, and sending an engine start-stop request signal to an engine controller according to control requirements to control the engine to stop; when the current vehicle speed is smaller than a preset third vehicle speed threshold value and the front hatch cover of the engine is in an open state, an engine starting request signal is sent to the engine controller, and the engine is controlled to start.

S2170, determining a twelfth start-stop control condition of the engine according to the current rotating speed of the motor and a preset rotating speed threshold value.

Wherein the eleventh start-stop control condition and the twelfth start-stop control condition are vehicle safety start-stop control conditions.

In this embodiment, the twelfth start-stop control condition of the engine may be determined according to the current rotation speed of the motor and the preset rotation speed threshold. Specifically, when the current rotating speed of the motor is greater than or equal to a preset rotating speed threshold value, an engine starting request signal is sent to an engine controller, and engine starting is controlled; and when the current rotating speed of the motor is smaller than the preset rotating speed threshold value, stopping the engine, sending an engine start-stop request signal to an engine controller, and controlling the engine to stop.

In an embodiment, fig. 3 is a flowchart of still another method for controlling start and stop of an engine of a hybrid vehicle according to an embodiment of the present invention, where the start and stop of the engine is controlled according to at least two start and stop control conditions and a preset start and stop priority level based on the above embodiments is further refined.

As shown in fig. 3, the method for controlling start and stop of the engine of the hybrid vehicle in the present embodiment may specifically include the steps of:

s310, judging whether the preset priority level is the first priority level, if so, executing S320; if not, S330 is performed.

In this embodiment, the preset priority level includes a first priority, a second priority, and a third priority; the first priority is greater than the second priority, which is greater than the third priority.

In this embodiment, the start-stop action sequence of the engine is determined according to the preset priority level, which can be understood that if the first priority level exists, an engine stop signal sent by the gearbox controller or the engine controller is received, an engine stop request signal is sent to the engine controller, and the engine is controlled to perform stop operation; if the priority is the second priority level, an engine starting signal sent by a gearbox controller or an engine controller is received, an engine starting request signal is sent to the engine controller, and the engine is controlled to start; and if the priority is the third priority level, controlling the engine to start and stop according to each start and stop control condition.

S320, sending an engine stop request signal to an engine controller to control the engine to stop.

In this embodiment, if the first priority level exists, an engine stop signal sent by the gearbox controller or the engine controller is received, and an engine stop request signal is sent to the engine controller to control the engine to perform a stop operation.

S330, continuously judging whether the first priority is the second priority, if so, executing S340; if not, S350 is performed.

In this embodiment, if the first priority level does not exist, whether the second priority level is continuously determined, if yes, an engine starting request signal is sent to the engine controller, the engine is controlled to perform a starting operation, and if not, whether the third priority level is continuously determined.

S340, sending an engine starting request signal to an engine controller to control the engine to start.

In this embodiment, if the priority is the second priority, an engine start request signal is sent to the engine controller to control the engine to start.

S350, continuously judging whether the first priority is the third priority, if so, executing S360; if not, the judgment is carried out again.

In this embodiment, if the engine is not in the second priority, whether the engine is in the third priority is continuously determined, if yes, the engine is controlled to start and stop according to each start and stop control condition, and if not, the engine is re-determined.

S360, controlling the engine to start and stop according to each start and stop control condition.

In the present embodiment, the engine start-stop may include: the motor drives the engine to perform engine start-stop operation and the starter controls the engine to perform start-stop operation, and the engine can be controlled to perform start-stop operation according to each start-stop control condition. In this embodiment, when the gear shift lever is a P (park) gear or an N (neutral) gear, the key is in a start state, and the vehicle controller detects a signal trigger without a failure of starting the vehicle by the starter, if the vehicle has a starting request and any one of the following conditions is satisfied, the vehicle controller controls the vehicle to start the engine by the starter, which may be understood as that the starting mode by the starter may include: 1) The electric quantity of the high-voltage battery is smaller than a specified value (such as 20 percent, and can be calibrated); 2) The available peak power of the motor is smaller than a specified value (such as 15kW, and can be calibrated); 3) The motor or battery fails, and the motor cannot be used to start the engine. In this embodiment, when the gear shift lever is any gear (P/R/N/D), the key is in a start state, and the vehicle controller detects a signal trigger without a motor start failure, and when the vehicle has a start request and the following conditions are all satisfied, the vehicle controller controls the vehicle motor to start the engine, which can be understood as that the motor start mode includes: 1) The electric quantity of the high-voltage battery is larger than a specified value (such as 25 percent, and can be calibrated); 2) The available peak power of the motor is larger than a specified value (such as 20kW and can be calibrated), and the continuous power of the motor is larger than the specified value (such as 15kW and can be calibrated); 3) The motor and battery are not subject to related faults, at which time the motor may be used to start the engine.

In one embodiment, controlling the engine to perform start-stop actions according to each start-stop control condition includes:

in a preset time period, if the required torque of the wheel end is larger than or equal to the difference value between the allowable torque of the motor and the reserved torque of the starting machine of the motor, an engine starting request signal is sent to an engine controller, and the starting machine of the engine is controlled;

in a preset time period, if the required torque of the wheel end is smaller than the difference value among the allowable torque of the motor, the reserved torque of the starting machine of the motor and the preset first regulating value, an engine starting and stopping request signal is sent to an engine controller, and the engine is controlled to stop;

when the current electric quantity maintenance mode is detected, and the available charging power of the motor is smaller than the reserved charging power of the motor starting, an engine starting request signal is sent to an engine controller to control the engine starting;

when detecting that the current power consumption mode exists or the available charging power of the motor is larger than or equal to the reserved charging power of the starting machine of the motor and a preset second regulating value, sending an engine starting and stopping request signal to an engine controller to control the stopping of the engine;

detecting that the starter is unavailable due to fault or the available discharge power of the motor is smaller than or equal to the difference value between the engine starting power and a preset third regulating value, sending an engine starting request signal to an engine controller, and controlling the engine to start;

Detecting that the starter is normally available, or that the available discharge power of the motor is larger than the sum of the starting power of the engine and a preset third regulating value, sending an engine starting and stopping request signal to an engine controller, and controlling the engine to stop;

in a preset time period, if the torque value of the wheel end of the vehicle generated by stepping on the accelerator pedal is detected to be larger than or equal to a preset wheel end standard value, an engine starting request signal is sent to an engine controller, and engine starting is controlled;

in a preset time period, if the torque value of the wheel end of the vehicle is smaller than the standard value of the preset wheel end, sending an engine start-stop request signal to an engine controller, and controlling the engine to stop;

detecting that the current driving mode is a motion mode, sending an engine starting request signal to an engine controller, and controlling the engine to start;

detecting that the vehicle is in an electric quantity maintaining mode, and in a preset time period, the vehicle required power of the target vehicle is greater than or equal to the engine starting power, sending an engine starting request signal to an engine controller, and controlling the engine to start;

detecting that the vehicle is in an electric quantity maintaining mode, and in a preset time period, the vehicle required power is smaller than the difference value between the engine starting power and a preset fourth regulating value, sending an engine starting and stopping request signal to an engine controller, and controlling the engine to stop;

When the temperature of the engine water is smaller than or equal to a preset engine temperature standard value, an engine starting request signal is sent to an engine controller, and engine starting is controlled;

when the temperature of the engine water is larger than a preset engine temperature standard value, sending an engine start-stop request signal to an engine controller according to control requirements, and controlling the engine to stop;

under the condition that the oil temperature of the gearbox is smaller than or equal to a preset oil temperature standard value, an engine starting request signal is sent to an engine controller, and engine starting is controlled;

under the condition that the oil temperature of the gearbox is larger than a preset oil temperature standard value, an engine start-stop request signal is sent to an engine controller according to control requirements, and the engine is controlled to stop;

when the state of charge of the power battery is smaller than or equal to a preset battery lower limit value, an engine starting request signal is sent to an engine controller, and engine starting is controlled;

when the state of charge of the power battery is larger than the preset battery upper limit value, an engine start-stop request signal is sent to an engine controller, and the engine is controlled to stop;

when the temperature of the high-voltage battery reaching the preset battery temperature threshold is smaller than the difference value between the preset battery starting temperature threshold and the preset fifth regulating value, an engine starting request signal is sent to an engine controller, and the engine starting is controlled;

When the temperature of the high-voltage battery reaching the preset battery temperature threshold is greater than or equal to the preset battery starting temperature threshold, controlling the engine to start by using a starter;

when the current vehicle speed is greater than or equal to a preset first vehicle speed threshold value, an engine starting request signal is sent to an engine controller, and engine starting is controlled;

when the current vehicle speed is greater than or equal to a preset second vehicle speed threshold value, stopping the engine, and sending an engine start-stop request signal to an engine controller according to control requirements to control the engine to stop;

when the current vehicle speed is greater than or equal to a preset third vehicle speed threshold value and the front hatch cover of the engine is in an open state, an engine starting request signal is sent to the engine controller, and the engine is controlled to start;

when the current rotating speed of the motor is greater than or equal to a preset rotating speed threshold value, an engine starting request signal is sent to an engine controller, and the engine is controlled to start;

and when the current rotating speed of the motor is smaller than the preset rotating speed threshold value, stopping the engine, sending an engine start-stop request signal to an engine controller, and controlling the engine to stop.

The first vehicle speed threshold value is larger than the second vehicle speed threshold value, and the second vehicle speed threshold value is larger than the third vehicle speed threshold value. The preset first vehicle speed threshold value, the preset second vehicle speed threshold value and the preset third vehicle speed threshold value can be set by people, experience and other modes. Illustratively, the first vehicle speed threshold is preset to 120km/h, the second vehicle speed threshold is preset to 110km/h, and the third vehicle speed threshold is preset to 2km/h.

In the embodiment, in a preset time period, if the required torque of the wheel end is greater than or equal to the difference value between the allowable torque of the motor and the reserved torque of the starting machine of the motor, an engine starting request signal is sent to an engine controller, and the starting machine of the engine is controlled; and in a preset time period, if the required torque of the wheel end is smaller than the difference value among the allowable torque of the motor, the reserved torque of the starting machine of the motor and the preset first regulating value, sending an engine starting and stopping request signal to an engine controller, and controlling the engine to stop. For example, if the driver wheel end required torque is greater than (the motor allowable torque minus the dynamic engine starting reserved torque) and the specified time is maintained within a certain period of time, the whole vehicle controller should send an engine starting request signal=1 to the engine controller so as to control the engine to start; when the driver demand torque is less than the motor allowable torque minus the dynamic engine starting reserved torque, and minus a hysteresis torque value (e.g. 10 Nm) for a prescribed time, the vehicle controller should send an engine starting request signal=0 to the engine controller to control the engine to stop. The hysteresis torque value is a preset first regulating value, and 1 represents True, namely the vehicle has an engine starting requirement; 0 indicates False, i.e. the vehicle has no engine start demand.

In some embodiments, when the current electric quantity maintenance mode is detected, and the available charging power of the motor is smaller than the reserved charging power of the motor starting, an engine starting request signal is sent to an engine controller, and the engine starting is controlled; and when detecting that the current power consumption mode exists or the available charging power of the motor is larger than or equal to the reserved charging power of the starting machine of the motor and a preset second regulating value, sending an engine starting and stopping request signal to an engine controller to control the stopping of the engine. For example, when the available charging power of the motor is smaller than the reserved charging power of the starting machine and is currently in a CS mode (electric quantity maintenance mode) and lasts for a specified time, the whole vehicle controller sends an engine starting request signal=1 to the engine controller to control the starting of the engine; when the available charging power of the motor is larger than the reserved charging power of the starting machine plus a hysteresis value (such as 2kW, which can be calibrated), or the motor is currently in a CD mode (electric quantity consumption mode) and lasts for a specified time, the whole vehicle controller sends an engine starting request signal=0 to the engine controller, and the engine is controlled to stop.

In some embodiments, detecting that the starter failure is unavailable or the available discharge power of the motor is smaller than or equal to the difference between the engine starting power and a preset third regulation value, sending an engine starting request signal to an engine controller, and controlling the engine to start; and detecting that the starter is normally available, or that the available discharge power of the motor is larger than the sum of the starting power of the engine and a preset third regulating value, sending an engine starting and stopping request signal to an engine controller, and controlling the engine to stop. For example, when the available discharge power of the motor is less than or equal to the engine start power, the preset third adjustment value (the preset third adjustment value=5 kW, calibratable) is subtracted, or the starter is unavailable due to fault, the whole vehicle controller sends an engine start request signal=1 to the engine controller to control the engine start; when the available discharge power of the motor is greater than the engine starting power and the preset third regulating value (the preset third regulating value=5 kW and the calibratable value) and the starter is normally available, the whole vehicle controller sends an engine starting request signal=0 to the engine controller to control the engine to stop.

In some embodiments, in a preset time period, if the torque value of the wheel end of the vehicle generated by stepping on the accelerator pedal is detected to be greater than or equal to a preset wheel end standard value, an engine starting request signal is sent to an engine controller, and the engine is controlled to start; and in a preset time period, if the torque value of the wheel end of the vehicle is smaller than the standard value of the preset wheel end, sending an engine start-stop request signal to an engine controller, and controlling the engine to stop. For example, when the vehicle is in the process of braking or sliding and the engine is stopped, if the driver steps on the accelerator pedal at the moment, the whole vehicle controller calculates that the wheel end of the vehicle is greater than a preset wheel end standard value (such as 100Nm and can be calibrated) for a period of time, the whole vehicle controller sends an engine start request signal=1 to the engine controller, and controls the engine to start; when the vehicle is in a braking or sliding process, the whole vehicle controller calculates that the wheel end of the vehicle is smaller than a preset wheel end standard value (such as 30Nm and can be calibrated) and lasts for a period of time, and then the whole vehicle controller sends an engine starting request signal=0 to the engine controller to control the engine to stop.

In some embodiments, detecting that the current driving mode is a motion mode, sending an engine starting request signal to an engine controller, and controlling the engine to start; it is understood that the vehicle driving modes include an E mode (economy mode), an N mode (normal mode), and an S mode (sport mode), and when the driver selects the S mode, in order to achieve better sport performance, the engine should be started at this time, and the whole vehicle controller sends an "engine start request signal=1" to the engine controller to control the engine start.

In some embodiments, it is detected that the vehicle is in a power-on-demand mode, and in a preset period of time, the vehicle demand power of the target vehicle is greater than or equal to the engine start power, an engine start request signal is sent to an engine controller, and engine start is controlled; the method comprises the steps of detecting that a vehicle is in an electric quantity maintaining mode, and in a preset time period, sending an engine start-stop request signal to an engine controller to control the engine to stop, wherein the vehicle required power is smaller than the difference value between the engine start-up power and a preset fourth regulating value. For example, when the vehicle is in the charge sustaining mode and the vehicle demand power exceeds the engine start power for a prescribed time, the overall vehicle controller sends an "engine start request signal=1" to the engine controller to control the engine start. When the vehicle is in the electric quantity maintaining mode and the vehicle required power is less than the engine starting power minus a preset fourth regulating value (such as 3kw, calibratable) and lasting for a prescribed time, the whole vehicle controller sends an engine starting request signal=0 to the engine controller to control the engine to stop.

In some embodiments, if the temperature of the engine water is less than or equal to a preset engine temperature standard value, sending an engine start request signal to an engine controller to control the engine start; and when the temperature of the engine water is larger than a preset engine temperature standard value, sending an engine start-stop request signal to an engine controller according to control requirements, and controlling the engine to stop. For example, in one driving cycle, if the engine is started, when the temperature of the engine is lower than the preset engine temperature standard value (such as 30 degrees celsius and can be calibrated), the whole vehicle controller sends an engine start request signal=1 to the engine controller to control the engine start. When the temperature of the engine water is larger than the preset standard value of the engine temperature (such as 40 ℃ and can be calibrated), the engine is allowed to be controlled to stop, and the whole vehicle controller can send an engine starting request signal=0 to the engine controller according to the control requirement to control the engine to stop.

In some embodiments, if the oil temperature of the gearbox is less than or equal to a preset oil temperature standard value, an engine start request signal is sent to an engine controller to control the engine to start; and under the condition that the oil temperature of the gearbox is larger than a preset oil temperature standard value, sending an engine start-stop request signal to an engine controller according to control requirements, and controlling the engine to stop. For example, when the oil temperature of the gearbox is smaller than a preset oil temperature standard value (such as 15 ℃ and can be calibrated), the whole vehicle controller sends an engine start request signal=1 to the engine controller to control the engine start; when the oil temperature of the gearbox is larger than a preset oil temperature standard value (such as 20 ℃ and can be calibrated), the engine is allowed to be controlled to stop, and the whole vehicle controller can send an engine starting request signal=0 to the engine controller according to control requirements to control the engine to stop.

In some embodiments, when the state of charge of the power battery is less than or equal to a preset battery lower limit value, an engine start request signal is sent to an engine controller to control the engine to start; when the state of charge of the power battery is larger than the preset battery upper limit value, an engine start-stop request signal is sent to an engine controller, and the engine is controlled to stop; for example, when the state of charge of the high-voltage battery is less than or equal to the preset lower limit value (for example, 30% and can be calibrated), the whole vehicle controller sends an engine start request signal=1 to the engine controller to control the engine start, and the high-voltage battery can be charged through engine operation. When the state of charge of the high-voltage battery is greater than the preset upper limit value (such as 90% and can be calibrated), the whole vehicle controller sends an engine starting request signal=0 to the engine controller to control the engine to stop, and the high-voltage battery can be preferentially used for discharging and driving the motor in the next vehicle driving running control, so that the vehicle is driven.

In some embodiments, when the temperature of the high-voltage battery reaching the preset battery temperature threshold is less than the difference between the preset battery start-up temperature threshold and the preset fifth adjustment value, an engine start-up request signal is sent to the engine controller to control the engine start-up; when the temperature of the high-voltage battery reaching the preset battery temperature threshold is greater than or equal to the preset battery starting temperature threshold, controlling the engine to start by using a starter; for example, when the maximum single temperature in the high-voltage battery is less than a preset battery starting temperature threshold (such as 55 ℃ and calibratable) minus a preset fifth adjustment value (such as 6 ℃ and calibratable), the high-voltage battery is allowed to discharge output energy to the motor for starting engine control; it should be noted that, when the maximum single temperature in the high-voltage battery is greater than the preset battery starting temperature threshold (for example, 55 ℃ and can be calibrated), the high-voltage battery is not allowed to be output to the motor for starting the engine, but the starter can be used for controlling the starting of the engine.

In some embodiments, when the current vehicle speed is greater than or equal to a preset first vehicle speed threshold, an engine start request signal is sent to an engine controller to control the engine to start; when the current vehicle speed is smaller than a preset second vehicle speed threshold, stopping the engine, and sending an engine start-stop request signal to an engine controller according to control requirements to control the engine to stop; when the current vehicle speed is smaller than a preset third vehicle speed threshold value and the front hatch cover of the engine is in an open state, an engine starting request signal is sent to the engine controller, and the engine is controlled to start; it should be noted that, the preset first vehicle speed threshold is greater than the preset second vehicle speed threshold, and the preset second vehicle speed threshold is greater than the preset third vehicle speed threshold. For example, when the vehicle speed is greater than a first vehicle speed threshold (e.g., 120km/h, calibratable), the overall vehicle controller sends an engine start request signal=1 to the engine controller to control engine start; when the vehicle speed is smaller than a second vehicle speed threshold (such as 110km/h, calibration is realized), the engine is allowed to stop, and the whole vehicle controller can send an engine starting request signal=0 to the engine controller according to control requirements to control the engine to stop. When the vehicle speed is smaller than a third vehicle speed threshold (such as 2km/h, calibration is realized) and the front hatch of the engine is in an open state, the whole vehicle controller sends an engine start request signal=1 to the engine controller, and the engine start is controlled. The engine is started to remind passengers or passersby, and the vehicle is running at the moment, so that the aim of the operation is to avoid the triggering accident caused by the fact that a person touches a high-voltage component in the front cabin. When the driver closes the front cabin cover of the engine, the whole vehicle controller sends an engine starting request signal=0 to the engine controller to control the engine to stop.

In some embodiments, when the current rotation speed of the motor is greater than or equal to a preset rotation speed threshold value, an engine starting request signal is sent to an engine controller to control the engine to start; when the current rotating speed of the motor is smaller than a preset rotating speed threshold value, stopping the engine, sending an engine start-stop request signal to an engine controller, and controlling the engine to stop; for example, when the motor speed is greater than a preset speed threshold (e.g., 3500rpm, calibratable), the overall vehicle controller sends an "engine start request signal=1" to the engine controller to control engine start. When the motor speed is lower than a preset speed threshold (such as 3000rpm, and can be calibrated), the engine is allowed to stop, and the whole vehicle controller can send an engine starting request signal=0 to the engine controller according to control requirements to control the engine to stop.

In one embodiment, controlling engine start includes:

controlling the output shaft torque of the gearbox controller to be reduced to the required torque so that the gearbox controller controls the clutch to be opened;

controlling a motor controller to increase motor torque and increase the motor rotation speed of the motor to a target rotation speed;

maintaining a target rotating speed to enable the motor controller to control the motor to drive the engine to run to the target rotating speed, and enabling the engine controller to control the engine to start ignition;

Under the condition that the engine controller controls the engine to successfully ignite, a control instruction is sent to control the motor controller so that the motor controller controls the motor to reduce torque;

sending a control command to an engine controller so that the engine controller controls the engine speed to continuously increase the speed to reach the target result speed on the basis of the target speed, and the gearbox controller controls the clutch to be closed;

and in the state that the clutch is closed, a control instruction is respectively sent to the engine controller and the motor controller so that the engine controller controls the engine to lift the torque, the motor controller controls the motor to reduce the torque, and when the torque is alternately controlled by the engine controller and the motor controller, the starting process of the engine is finished.

In this embodiment, the output shaft torque of the transmission controller is controlled to be reduced to the required torque so that the transmission controller controls the clutch to be opened; controlling a motor controller to increase motor torque and increase the motor rotation speed of the motor to a target rotation speed; maintaining a target rotating speed to enable the motor controller to control the motor to drive the engine to run to the target rotating speed, and enabling the engine controller to control the engine to start ignition; under the condition that the ignition of the engine is successful, a control instruction is sent to control the motor controller so that the motor controller controls the motor to reduce torque; sending a control command to an engine controller so that the engine controller controls the engine speed to continuously increase the speed to reach the target result speed on the basis of the target speed, and the gearbox controller controls the clutch to be closed; and in the state that the clutch is closed, a control instruction is respectively sent to the engine controller and the motor controller so that the engine controller controls the engine to lift the torque, the motor controller controls the motor to reduce the torque, and when the torque is alternately controlled by the engine controller and the motor controller, the starting process of the engine is finished.

According to the technical scheme, the motor allowable torque, the motor starting reserved torque, the motor available charging power, the motor available discharging power, the motor starting reserved charging power, the motor starting reserved discharging power, the current motor rotating speed and the motor target rotating speed are obtained from the motor controller; acquiring the current speed of a target vehicle from a vehicle body electronic stabilization system; acquiring a gearbox oil temperature from a gearbox controller; acquiring engine starting power and engine water temperature of an engine from an engine controller, forming control parameter information, respectively determining starting and stopping control conditions of the engine in a target vehicle based on the control parameter information, determining the starting and stopping action sequence of the engine according to a preset priority level, and judging whether the preset priority level is a first priority level; if yes, sending an engine stopping request signal to an engine controller, and controlling the engine to stop; if not, continuously judging whether the engine is in the second priority, if so, sending an engine starting request signal to an engine controller to control the engine to start operation, if not, continuously judging whether the engine is in the third priority, if so, controlling the engine to start and stop according to each start and stop control condition to further and more effectively identify when to control the engine to start from multiple aspects, reasonably control the engine start and stop under different conditions, and ensure the stability and reliability in the running process of the vehicle, thereby providing better vehicle performance for users.

In one embodiment, to facilitate better understanding of the method for controlling engine start and stop of a hybrid vehicle, fig. 4 is a flowchart of another method for controlling engine start and stop of a hybrid vehicle according to an embodiment of the present invention. In the embodiment, the preset priority level is used as the third priority, the engine start-stop control module is developed in the whole vehicle controller based on the whole vehicle controller as a core by designing the engine start-stop function control framework, and various factors and conditions such as the dynamic property, the driving property, the economy, the component warmup, the high-voltage battery, the safety of the vehicle and the like of the vehicle are considered in the engine start-stop control process.

As shown in fig. 4, the specific steps of the engine start-stop control method of the hybrid vehicle are as follows:

a1, acquiring control parameter information transmitted by a plurality of controllers.

and a2, under the condition that the priority is the third priority, determining engine start-stop control conditions according to control parameter information, wherein the engine start-stop control function mainly comprises engine start-stop control, start-stop arbitration function and the like, and the engine start-stop control mainly comprises 7 types, namely power start-up trigger control, drivability start-up trigger control, economy start-up trigger control, component warm-up start-up trigger control, high-voltage battery start-up trigger control, vehicle safety start-up trigger control, external other start-up trigger control and stop trigger control under corresponding conditions.

In the embodiment, a first start-stop control condition of an engine is determined according to a wheel end required torque, a motor allowable torque and a motor start-up reserved torque; wherein the first start-stop control condition is a dynamic start-stop control condition; determining a second start-stop control condition of the engine according to the available charging power of the motor, the reserved charging power of the starting machine of the motor and the electric quantity mode; determining a third start-stop control condition according to the available discharge power of the motor, the available start-up power of the engine and whether the starter is available; receiving a vehicle wheel end torque value generated by a user stepping on an accelerator pedal of a target vehicle when the target vehicle is in a sliding or braking process, and determining a fourth start-stop control condition of the engine according to the vehicle wheel end torque value and a preset wheel end standard value; determining a fifth start-stop control condition according to the driving mode of the target vehicle, wherein the second start-stop control condition, the third start-stop control condition, the fourth start-stop control condition and the fifth start-stop control condition are driving start-stop control conditions; detecting that the target vehicle is in an electric quantity maintenance mode, and determining a sixth start-stop control condition of the engine according to the vehicle demand power of the target vehicle and the engine start-stop power; the sixth start-stop control condition is an economical start-stop control condition; determining a seventh start-stop control condition of the engine according to the water temperature of the engine and a preset engine temperature standard value; determining an eighth start-stop control condition of the engine according to the oil temperature of the gearbox and a preset oil temperature standard value; wherein the seventh start-stop control condition and the eighth start-stop control condition are partial warm-up start-stop control conditions; determining a ninth start-stop control condition of the engine according to the state of charge of the power battery, the preset battery lower limit value and the preset battery upper limit value; when the temperature of the power battery is detected to reach a preset battery starting temperature threshold value, determining a tenth starting and stopping control condition of the engine according to the temperature of the high-voltage battery and the battery starting temperature; the ninth start-stop control condition and the tenth start-stop control condition are power battery start-stop control conditions; determining an eleventh start-stop control condition of the engine according to the current vehicle speed and a preset vehicle speed threshold value; determining a twelfth start-stop control condition of the engine according to the current rotating speed of the motor and a preset rotating speed threshold value; the eleven start-stop control conditions and the twelve start-stop control conditions are vehicle safety start-stop control conditions.

In addition to other external start-stop control conditions, the vehicle controller should send an engine start request signal=0 to the engine controller to control the engine to remain in a stopped state, for example, when the vehicle is in a transportation or diagnostic service. When the vehicle is not in transportation or in diagnostic service, the whole vehicle controller can send an engine start request signal=0 to the engine controller according to control requirements to control the engine to stop.

and a3, under the condition that any starting/stopping trigger control is met, judging the starting/stopping conditions of the engine, and performing starting and stopping control operations of the engine according to the judging results of the conditions.

In an embodiment, in order to better understand a control process of starting a motor-driven engine, fig. 5 is a schematic diagram of a control process of starting a motor-driven engine according to an embodiment of the present invention, where in this embodiment, a whole vehicle controller is used as a core controller, and when it is determined that a vehicle meets a certain start-stop condition or strategy, the engine needs to be controlled to start or stop, where a control step of starting the engine by using a motor is shown in fig. 5, and specific steps are as follows:

S510, the whole vehicle controller coordinates and controls the output shaft torque of the gearbox to be reduced to the torque required by the driver, namely, the torque reducing process of the power source is controlled, namely, the output shaft torque is required to meet the torque required by the driver.

S520, the gearbox controller controls the clutch to be opened.

And S530, controlling the motor controller to lift the torque of the motor, and increasing the rotating speed of the motor to the target rotating speed, namely controlling the speed regulation process of the power source.

S540, the gearbox controller controls the clutch to increase torque and enter a slipping state.

S550, the motor controller controls the motor to further increase the torque to maintain the target rotating speed, the engine starts to increase the rotating speed under dragging of the motor, and ignition is started after the rotating speed of the engine is increased to the ignition rotating speed.

And S560, after the ignition of the engine is successful, the gearbox controller controls the clutch to be opened, and the motor controller controls the motor to start reducing the torque.

And S570, controlling the engine speed to continuously rise by the engine controller and adopting the speed control after reaching the stable speed, and controlling the clutch to be closed by the gearbox controller after synchronizing with the motor speed.

And S580, performing torque control after the clutch is closed, controlling the engine to lift the torque by the engine controller, controlling the motor to reduce the torque by the motor controller, and ending the engine starting process after the torque alternation control is realized by the engine controller and the motor controller.

In one embodiment, fig. 6 is a block diagram of a hybrid vehicle engine start-stop control system according to an embodiment of the present invention. As shown in fig. 6, a hybrid vehicle powertrain, the system comprising: engine 620, motor 630, and vehicle controller 610;

the engine 620 is connected to the vehicle controller 610 and the motor 630, and is configured to generate engine start power and engine water temperature, and send the engine start power and the engine water temperature of the engine 620 to the vehicle controller 610, and perform start or stop operations when a start-stop control condition is satisfied;

the motor 630 is connected to the vehicle controller 610 and the engine 620, and is configured to generate a motor required torque, a starting reserved torque, a motor available charging/discharging power, a starting reserved charging/discharging power, and a motor rotation speed, and to drive the engine to start when the engine starting operation is satisfied;

the vehicle controller 610, coupled to the electric machine 630 and the engine 620, is configured to implement the method according to any one of the embodiments of the present invention.

In an embodiment, the system further comprises: the system comprises a battery management system, a motor controller, a gearbox controller, an engine controller and a vehicle body electronic stabilization system;

The battery management system is connected to the vehicle controller 610 and the power battery, for controlling the charge and discharge of the battery, and transmits the parameter information of charge and discharge to the vehicle controller 610;

the motor controller is connected with the motor and the whole vehicle controller 610, and is used for controlling the charge, discharge and motor rotation speed of the motor and transmitting the motor to the whole vehicle controller 610;

the electronic stabilizing system of the vehicle body is connected with the whole vehicle controller 610 and is used for calculating the speed of the vehicle and transmitting the speed to the whole vehicle controller 610;

the engine controller is connected with the engine and the whole vehicle controller 610, and is used for controlling the engine to start and stop, and transmitting the generated engine starting power and the generated engine water temperature to the whole vehicle controller 610;

the gearbox controller is connected with the gearbox and the whole vehicle controller 610, and is used for controlling the oil temperature of the gearbox and transmitting the oil temperature to the whole vehicle controller 610.

In one embodiment, to facilitate a better understanding of a hybrid vehicle powertrain, FIG. 7 is a block diagram of yet another hybrid vehicle engine start-stop control system provided in an embodiment of the present invention. In this embodiment, the hybrid vehicle power system mainly comprises assembly components such as a battery management system 710, a motor controller 720, a motor 730, a gearbox controller 740, a gearbox 750, an engine controller 760, an engine 770, a clutch, a whole vehicle controller 780, and a transmission mechanism, wherein the controllers communicate with each other through a CAN network, and a specific connection manner is shown in fig. 6. In this embodiment, the battery management system 710 is configured to control charging and discharging of the battery, and transmit parameter information of charging and discharging to the vehicle controller 780; the motor controller 720 is used for controlling the charge and discharge of the motor and the rotation speed of the motor, and transmits the charge and discharge to the vehicle controller 780; the engine controller 760 is configured to control the engine 770 to perform start-stop operation, and transmit the generated engine start-up power and the generated engine water temperature to the vehicle controller 780; the transmission controller 740 is connected to the transmission 750 and the vehicle controller 780, and is configured to control the transmission oil temperature and transmit the same to the vehicle controller 780.

It should be appreciated that various forms of the flows shown above may be used to reorder, add, or delete steps. For example, the steps described in the present invention may be performed in parallel, sequentially, or in a different order, so long as the desired results of the technical solution of the present invention are achieved, and the present invention is not limited herein.

The above embodiments do not limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.

Claims

1. The method is characterized by being applied to a whole vehicle controller, and comprises the following steps:

2. The method of claim 1, wherein receiving control parameter information transmitted by at least two controllers in a target vehicle comprises:

acquiring the state of charge, battery temperature, battery starting temperature and electric quantity mode of a power battery from a battery management system; wherein the power mode includes a power maintenance mode and a power consumption mode;

acquiring motor allowable torque, motor starting reserved torque, motor available charging power, motor available discharging power, motor starting reserved charging power, motor starting reserved discharging power, motor current rotating speed and motor target rotating speed from a motor controller;

acquiring the current speed of the target vehicle from a vehicle body electronic stabilization system;

acquiring a gearbox oil temperature from a gearbox controller;

and acquiring the engine starting power and the engine water temperature of the engine from an engine controller.

3. The method according to claim 2, wherein the determining start-stop control conditions of the engine in the target vehicle based on each of the control parameter information, respectively, includes at least one of:

acquiring a wheel end required torque when a user steps on the target vehicle pedal;

Determining a first start-stop control condition of the engine according to the wheel end required torque, the motor allowable torque and the motor starting reserved torque; wherein the first start-stop control condition is a dynamic start-stop control condition;

determining a second start-stop control condition of the engine according to the available charging power of the motor, the reserved charging power of the starting machine of the motor and the electric quantity mode;

determining a third start-stop control condition according to the available discharge power of the motor, the starting power of the engine and whether a starter is available;

receiving a vehicle wheel end torque value generated by a user stepping on an accelerator pedal of the target vehicle when the target vehicle is in a sliding or braking process, and determining a fourth start-stop control condition of the engine according to the vehicle wheel end torque value and a preset wheel end standard value;

determining a fifth start-stop control condition according to the driving mode of the target vehicle, wherein the second start-stop control condition, the third start-stop control condition, the fourth start-stop control condition and the fifth start-stop control condition are driving start-stop control conditions;

detecting that the target vehicle is in an electric quantity maintaining mode, and determining a sixth start-stop control condition of the engine according to the vehicle required power of the target vehicle and the engine start-stop power; wherein the sixth start-stop control condition is an economical start-stop control condition;

Determining a seventh start-stop control condition of the engine according to the engine water temperature and a preset engine temperature standard value;

determining an eighth start-stop control condition of the engine according to the oil temperature of the gearbox and a preset oil temperature standard value; wherein the seventh start-stop control condition and the eighth start-stop control condition are partial warm-up start-stop control conditions;

determining a ninth start-stop control condition of the engine according to the state of charge of the power battery, a preset battery lower limit value and a preset battery upper limit value;

when the temperature of the power battery is detected to reach a preset battery starting temperature threshold value, determining a tenth starting and stopping control condition of the engine according to the temperature of the high-voltage battery and the battery starting temperature; wherein the ninth start-stop control condition and the tenth start-stop control condition are power battery start-stop control conditions;

determining an eleventh start-stop control condition of the engine according to the current vehicle speed and a preset vehicle speed threshold value;

determining a twelfth start-stop control condition of the engine according to the current rotating speed of the motor and a preset rotating speed threshold value; the eleven start-stop control conditions and the twelve start-stop control conditions are vehicle safety start-stop control conditions.

4. The method of claim 1, wherein said controlling the engine to start and stop according to at least two of said start and stop control conditions and a preset start and stop priority level comprises:

judging whether the preset priority level is the first priority level or not; the preset priority level comprises a first priority, a second priority and a third priority; the first priority is greater than the second priority, which is greater than the third priority;

if yes, sending an engine stopping request signal to an engine controller, and controlling the engine to stop; if not, continuing to judge whether the engine is at the second priority, if so, sending an engine starting request signal to an engine controller to control the engine to start operation, if not, continuing to judge whether the engine is at the third priority, and if so, controlling the engine to start and stop according to each start and stop control condition.

5. A method according to claim 3, wherein the engine start-stop comprises: the motor drives the engine to perform engine start-stop operation and starter control engine start-stop operation, and the engine is controlled to perform start-stop operation according to each start-stop control condition, comprising:

in the preset time period, if the wheel end required torque is smaller than the difference value among the motor allowable torque, the motor starting reserved torque and the preset first regulating value, an engine starting and stopping request signal is sent to the engine controller, and the engine is controlled to stop;

when the current electric quantity maintenance mode is detected, and the available charging power of the motor is smaller than the reserved charging power of the motor starting, an engine starting request signal is sent to the engine controller to control the engine starting;

when detecting that the current power consumption mode exists or the available charging power of the motor is larger than or equal to the reserved charging power of the starting machine of the motor and a preset second regulating value, sending an engine start-stop request signal to the engine controller to control the engine to stop;

detecting that the starter is unavailable due to fault or the available discharge power of the motor is smaller than or equal to the difference value between the engine starting power and a preset third regulating value, and sending an engine starting request signal to the engine controller to control the engine to start;

Detecting that a starter is normally available, or that the available discharge power of the motor is larger than the sum of the engine starting power and the preset third regulating value, sending an engine starting and stopping request signal to the engine controller, and controlling the engine to stop;

in the preset time period, if the torque value of the wheel end of the vehicle generated by stepping on the accelerator pedal is detected to be larger than or equal to the preset wheel end standard value, an engine starting request signal is sent to the engine controller, and engine starting is controlled;

in the preset time period, if the torque value of the wheel end of the vehicle is smaller than the standard value of the preset wheel end, an engine start-stop request signal is sent to the engine controller to control the engine to stop;

detecting that the current driving mode is a motion mode, sending an engine starting request signal to the engine controller, and controlling the engine to start;

detecting that the vehicle is in an electric quantity maintaining mode, and in the preset time period, the vehicle required power of the target vehicle is greater than or equal to the engine starting power, sending an engine starting request signal to the engine controller, and controlling the engine to start;

detecting that the vehicle is in an electric quantity maintaining mode, and in the preset time period, sending an engine start-stop request signal to the engine controller to control the engine to stop, wherein the vehicle required power is smaller than the difference value between the engine start-up power and a preset fourth regulating value;

When the temperature of the engine water is smaller than or equal to a preset engine temperature standard value, an engine starting request signal is sent to the engine controller to control the engine to start;

when the temperature of the engine water is larger than the preset engine temperature standard value, sending an engine start-stop request signal to the engine controller according to control requirements, and controlling the engine to stop;

under the condition that the oil temperature of the gearbox is smaller than or equal to a preset oil temperature standard value, an engine starting request signal is sent to the engine controller, and engine starting is controlled;

when the oil temperature of the gearbox is larger than the preset oil temperature standard value, an engine start-stop request signal is sent to the engine controller according to control requirements, and the engine is controlled to stop;

when the state of charge of the power battery is smaller than or equal to a preset battery lower limit value, an engine starting request signal is sent to the engine controller, and engine starting is controlled;

when the state of charge of the power battery is larger than a preset battery upper limit value, an engine start-stop request signal is sent to the engine controller to control the engine to stop;

when the temperature of the high-voltage battery reaching the preset battery temperature threshold is smaller than the difference value between the preset battery starting temperature threshold and the preset fifth regulating value, an engine starting request signal is sent to the engine controller, and the engine starting is controlled;

when the current vehicle speed is greater than or equal to a preset first vehicle speed threshold value, an engine starting request signal is sent to the engine controller, and engine starting is controlled;

when the current vehicle speed is smaller than the preset second vehicle speed threshold value, stopping the engine, and sending an engine start-stop request signal to the engine controller according to control requirements to control the engine to stop;

when the current vehicle speed is smaller than the preset third vehicle speed threshold and the front hatch cover of the engine is in an open state, an engine starting request signal is sent to the engine controller to control the engine to start, wherein the preset first vehicle speed threshold is larger than the preset second vehicle speed threshold, and the preset second vehicle speed threshold is larger than the preset third vehicle speed threshold;

when the current rotating speed of the motor is greater than or equal to the preset rotating speed threshold, an engine starting request signal is sent to the engine controller, and engine starting is controlled;

and when the current rotating speed of the motor is smaller than the preset rotating speed threshold value, stopping the engine, sending an engine start-stop request signal to the engine controller, and controlling the engine to stop.

6. The method of claim 5, wherein said controlling engine start comprises:

controlling the output shaft torque of a gearbox controller to be reduced to required torque so that the gearbox controller controls a clutch to be opened;

controlling a motor controller to increase motor torque and increasing the motor speed of the motor to a target speed;

maintaining the target rotating speed to enable the motor controller to control the motor to drive the engine to run to the target rotating speed, and enabling the engine controller to control the engine to start ignition;

sending a control command to the engine controller so that the engine controller controls the engine speed to continuously increase the speed to reach the target result speed on the basis of the target speed, and the gearbox controller controls the clutch to be closed;

and in the state that the clutch is closed, a control instruction is respectively sent to the engine controller and the motor controller so that the engine controller controls the engine to lift the torque, the motor controller controls the motor to reduce the torque, and when the torque is alternately controlled, the engine starting process is finished.

7. The method of claim 1, wherein the dividing of the preset start-stop priority level comprises: a first priority, a second priority, and a third priority, wherein the first priority is greater than the second priority, and the second priority is greater than the third priority;

wherein the first priority includes: receiving an engine stop signal sent by a gearbox controller or an engine controller, sending an engine stop request signal to the engine controller, and controlling the engine to stop;

the second priority includes: receiving an engine starting signal sent by the gearbox controller or the engine controller, sending an engine starting request signal to the engine controller, and controlling the engine to start;

the third priority includes: and any one of the start-stop control conditions.

8. The method according to claim 1, wherein the control parameter information comprises at least: the method comprises the following steps of motor allowable torque, reserved torque when a motor starts, motor available charging power, motor available discharging power, motor starting reserved charging power, motor starting reserved discharging power, motor rotating speed, motor target rotating speed, engine starting power, vehicle wheel end torque value, driving mode, engine water temperature, gearbox oil temperature, state of charge of a high-voltage battery, temperature of the high-voltage battery, battery starting temperature and vehicle speed.

9. A hybrid vehicle powertrain, the system comprising: the system comprises an engine, a motor and a whole vehicle controller;

the vehicle control unit is connected with the motor and the engine and is used for executing the method of claims 1-7.

10. The system of claim 9, wherein the system further comprises: the system comprises a battery management system, a motor controller, a gearbox controller, an engine controller and a vehicle body electronic stabilization system;

the battery management system is connected with the whole vehicle controller and the power battery, and is used for controlling the charging and discharging of the battery and transmitting the parameter information of the charging and discharging to the whole vehicle controller;

The motor controller is connected with the motor and the whole vehicle controller, and is used for controlling the charge and discharge of the motor and the rotation speed of the motor and transmitting the motor to the whole vehicle controller;

the vehicle body electronic stabilizing system is connected with the whole vehicle controller and is used for calculating the vehicle speed and transmitting the vehicle speed to the whole vehicle controller;

the engine controller is connected with the engine and the whole vehicle controller and is used for controlling the engine to start and stop and transmitting the generated engine starting power and the generated engine water temperature to the whole vehicle controller;

the gearbox controller is connected with the gearbox and the whole vehicle controller and is used for controlling the oil temperature of the gearbox and transmitting the oil temperature to the whole vehicle controller.