CN113879275B

CN113879275B - Engine starting method and device

Info

Publication number: CN113879275B
Application number: CN202111155105.0A
Authority: CN
Inventors: 何林林; 杜金鑫; 陈志鹏
Original assignee: Chery Automobile Co Ltd
Current assignee: Chery Automobile Co Ltd
Priority date: 2021-09-29
Filing date: 2021-09-29
Publication date: 2023-06-27
Anticipated expiration: 2041-09-29
Also published as: CN113879275A

Abstract

The application relates to the technical field of automobiles and discloses an engine starting method and device, wherein the method comprises the following steps: acquiring the residual capacity and the battery temperature of a high-voltage battery in a vehicle, gear information and the current speed; and judging which starting mode of the vehicle is suitable for executing the starting of the motor under neutral gear, the starting of the motor during running, the starting of the starter during running and the starting of the starter under neutral gear. The engine starting method and the engine starting device can improve the reliability and the stability of engine starting.

Description

Engine starting method and device

Technical Field

The application relates to the technical field of vehicles, in particular to an engine starting method and device.

Background

Hybrid electric vehicles (Hybrid Electric Vehicle, HEV) have multiple power sources therein, including an engine and an electric machine. In the interval of high fuel consumption of the engine, a part of power is supplied by the motor in a supplementing way so as to improve the drivability and reduce the fuel consumption. During braking or low battery idle speed, the motor may recover energy and charge the high voltage battery to achieve electrical balance.

Currently, the engine in a hybrid vehicle is often powered by an electric motor. However, in a low temperature environment or when the battery power is low, the engine cannot be started normally due to the fact that the motor is used for providing starting power. How to ensure the reliability of the engine start is still a problem to be solved.

Disclosure of Invention

In view of this, the present application provides an engine starting method and apparatus, which can improve the reliability and stability of engine starting. Specifically, the method comprises the following technical scheme:

the embodiment of the application provides an engine starting method, which comprises the following steps:

acquiring the residual capacity and the battery temperature of a high-voltage battery in a vehicle, gear information and the current speed;

when the residual electric quantity is not smaller than an electric quantity threshold value and the battery temperature is not smaller than a temperature threshold value, judging whether the vehicle is in a neutral state according to the gear information;

executing a neutral motor start when the vehicle is in the neutral state;

when the vehicle is not in the neutral state, the current vehicle speed is not less than a vehicle speed threshold value, and the maximum starting torque of the motor is not less than the engine starting torque limit, starting the motor in running;

executing starter starting in running when the vehicle is not in the neutral state and the current vehicle speed is smaller than a vehicle speed threshold value or the maximum starting torque of the motor is smaller than the engine starting torque limit; and is also provided with

And executing the starting of the starter under neutral gear when the residual electric quantity is smaller than an electric quantity threshold value or the battery temperature is smaller than a temperature threshold value and the vehicle is in the neutral gear state.

In an implementation manner of the embodiment of the present application, the executing the start of the motor under neutral gear includes:

acquiring a clutch state, a clutch rotating speed and a motor rotating speed;

requesting the clutch to be quickly combined when the clutch is in a torque control state and the motor rotating speed is higher than the clutch rotating speed;

acquiring the rotating speed of an engine, and requesting the clutch to slide and grind when the rotating speed of the engine is larger than the starting demand rotating speed of the engine;

when the engine is in an operating state and the clutch is in a closed state, the motor is requested to withdraw torque.

In an implementation manner of the embodiment of the present application, the executing the start of the motor during running includes:

requesting a clutch slip mill;

requesting the clutch to close when the engine speed and the motor speed are synchronized;

when the wheel end torques respectively provided by the engine and the motor are synchronous, starting is finished.

In an implementation manner of the embodiment of the present application, the executing starter starting during driving includes:

starting the starter and requesting the clutch slip film;

and when the time of the engine in the running state reaches the preset time, starting is finished.

In an implementation manner of the embodiment of the present application, the performing starter starting includes:

acquiring an engine state and a clutch state;

requesting the starter to stop and requesting the clutch to be engaged slowly when the engine is in an operating state and the clutch is in a torque control state;

acquiring the rotation speed of an engine, and requesting the clutch to slide and grind when the rotation speed of the engine is synchronous with the rotation speed of a motor;

when the clutch is in a closed state, the start-up is ended.

The embodiment of the application also provides an engine starting device, which comprises: the acquisition module is configured to acquire the residual capacity and the battery temperature of the high-voltage battery in the vehicle, gear information and the current vehicle speed;

the judging module is configured to judge whether the vehicle is in a neutral state according to the gear information when the residual electric quantity is not less than an electric quantity threshold value and the battery temperature is not less than a temperature threshold value;

an execution module configured to execute a neutral motor start when the vehicle is in the neutral state; when the vehicle is not in the neutral state, the current vehicle speed is not less than a vehicle speed threshold value, and the maximum starting torque of the motor is not less than the engine starting torque limit, starting the motor in running; executing starter starting in running when the vehicle is not in the neutral state and the current vehicle speed is smaller than a vehicle speed threshold value or the maximum starting torque of the motor is smaller than the engine starting torque limit; and executing a neutral-down starter start when the remaining charge is less than a charge threshold or the battery temperature is less than the temperature threshold and the vehicle is in the neutral state.

In one implementation manner of the embodiment of the present application, the execution module is further configured to:

acquiring a clutch state, a clutch rotating speed and a motor rotating speed;

requesting a clutch slip mill;

starting the starter and requesting the clutch slip film;

acquiring an engine state and a clutch state;

when the clutch is in a closed state, the start-up is ended.

The beneficial effects of the technical scheme provided by the embodiment of the application at least comprise:

the engine starting method and the engine starting device provided by the embodiment of the application comprise various starting modes of various engines, so that normal starting of the engines can be realized under different working conditions, and the reliability and the stability of engine starting are ensured.

Drawings

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

Fig. 1 shows a schematic diagram of an implementation environment of an intelligent driving system according to an embodiment of the present application;

FIG. 2 is a flow chart of an engine starting method according to an embodiment of the present disclosure;

fig. 3 is a schematic flow chart of performing a start of a motor under neutral gear according to an embodiment of the present application;

fig. 4 shows a schematic flow chart of starting a motor in running according to an embodiment of the present application;

fig. 5 shows a schematic flow chart of starting a starter in driving according to an embodiment of the present application;

fig. 6 shows a schematic flow chart of starting a starter under neutral gear according to an embodiment of the present application;

fig. 7 shows a schematic structural diagram of an engine starting device according to an embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure. In order to make the technical solution and advantages of the present application more clear, the engine starting method and the like will be described in detail with reference to the accompanying drawings.

The new energy vehicle of the HEV is a non-plug-in hybrid electric vehicle, which has two power devices, namely a power motor (hereinafter referred to as "motor") and an engine. The motor is powered by the high-voltage battery, or the motor can also store energy for the high-voltage battery. The engine operating power may then be provided by a battery. The voltage of the high voltage battery may be generally above 400V, while the voltage of the low voltage battery may be, for example, 12V. As shown in fig. 1, the hybrid vehicle may be classified into P0, P1, P2, P3, and P4 hybrid architectures according to the arrangement positions of the motors. The P2 hybrid architecture is widely used because of the relative ease of implementation and the small changes to the original gearbox (Continuously Variable Transmission, CVT) production line. As shown in fig. 1, in a P2 hybrid architecture, the electric machine may be placed at the input of the gearbox, between the engine and the gearbox. In a conventional P2 hybrid architecture, a clutch K0 is provided between the motor and the engine, and a clutch K1 is provided between the motor and the transmission.

In the P2 hybrid architecture, when the vehicle is in a pure electric mode, the motor rotates at high speed and the engine is stationary, at which time the K1 clutch is engaged and the K0 clutch is opened; when the vehicle is in the hybrid drive mode, the K0 and K1 clutches are simultaneously engaged; when the vehicle is in a deceleration or coasting mode, the K1 clutch is engaged to cause the motor to generate electricity and the K0 clutch is opened.

Because two sets of power sources capable of working independently or simultaneously exist in the hybrid electric vehicle, when starting the engine is the core control content of the hybrid strategy.

The application provides an engine starting method which can be applied to a hybrid electric vehicle with the P2 hybrid architecture.

Under the conditions of sufficient electric quantity and proper temperature condition of the battery, a pure electric mode is used by default; and when the power is low (e.g., below a predetermined threshold) or the temperature is low, the hybrid mode is used by default. According to the performance and efficiency characteristics of the motor and the engine, the motor is generally used for driving under the low-speed working condition, and the engine is used for driving the vehicle under the high-speed working condition. Two important influencing factors for determining whether the engine is started are respectively as follows: the maximum electric drive power that the present vehicle can provide, and a State Of Charge (SOC) threshold Of the battery.

When a hybrid control unit (Hybrid Control Unit, HCU) in the vehicle determines that the current maximum electric drive power cannot meet the driving requirement of a driver, the HCU makes an engine start request and starts the engine after the HCU determines permission. The maximum electric drive power is affected by the residual capacity of the high-voltage battery, the temperature of the electric drive system and other related factors. The driver demand power is determined by the vehicle travel speed, motor/engine speed, and accelerator pedal opening. The residual electric quantity threshold value is calibrated according to parameters such as the vehicle speed, and when the vehicle is in a low-speed working condition, the motor is preferentially used for driving.

Under the condition that the engine needs to be started, how to start the engine under different working conditions so as to ensure the reliability of engine starting is an important control module of the HCU.

The present application provides a method for starting an engine, as shown in fig. 2, the method comprising:

s201, acquiring the residual capacity and the battery temperature of a high-voltage battery in a vehicle, gear information and the current speed;

s202, judging whether the vehicle is in a neutral state according to gear information when the residual electric quantity is not less than an electric quantity threshold value and the battery temperature is not less than a temperature threshold value;

s203, when the vehicle is in a neutral state, executing the start of a neutral motor;

s204, when the vehicle is not in a neutral state, the current vehicle speed is not less than a vehicle speed threshold value, and the maximum starting torque of the motor is not less than the engine starting torque limit, starting the motor in running;

s205, when the vehicle is not in a neutral state and the current vehicle speed is smaller than a vehicle speed threshold value or the maximum starting torque of the motor is smaller than the engine starting torque limit, starting the starter in running;

and S206, when the residual electric quantity is smaller than the electric quantity threshold value or the battery temperature is smaller than the temperature threshold value and the vehicle is in a neutral state, starting the starter under the neutral state.

The engine starting method comprises various starting modes of various engines, normal starting of the engines can be achieved under different working conditions, and reliability and stability of engine starting are guaranteed.

Optionally, performing a neutral motor start includes:

acquiring a clutch state, a clutch rotating speed and a motor rotating speed;

when the clutch is in a torque control state and the motor rotating speed is higher than the clutch rotating speed, requesting the clutch to be quickly combined;

when the engine is in an operating state, the clutch is requested to close and the motor withdraws torque.

Optionally, performing the running motor start includes:

requesting a clutch slip mill;

requesting the clutch to slip when the engine is in an operating state and the clutch is in a closed state;

when the wheel end torques respectively provided by the engine and the motor are synchronous, the starting is finished.

Optionally, performing the start of the running starter includes:

requesting a clutch slip mill;

Optionally, performing starter starting includes:

acquiring an engine state and a clutch state;

when the engine is in an operating state and the clutch is in a torque control state, requesting the starter to stop and requesting the clutch to be combined slowly;

when the clutch is in the closed state, the start-up is ended.

The engine starting method provided by the application can be executed by the HCU, and in a specific implementation, the engine starting method can be integrated into an engine starting control module in the HCU in a program or instruction mode. The HCU may interact with controllers in a hybrid vehicle such as an ECU, TCU (Transmission Control Unit, automatic transmission control unit), MCU (Motor Control Unit ), and BMS (Battery Management System, battery management system).

When the HCU determines that the engine needs to be started or an engine start request is received from the outside, it may first determine whether the engine can be started by the motor according to the SOC of the high-voltage battery and the battery temperature. The battery temperature may refer to the ambient temperature in which the high voltage battery is located, or may specifically be the temperature of the circulating water in the high voltage battery. Specifically, the HCU may transmit a battery status acquisition request to the BMS, and the BMS transmits the current remaining power of the high-voltage battery and the battery temperature to the HCU in response to the battery status acquisition request. In addition, the HCU may send a vehicle running state acquisition request to the ECU to acquire the current vehicle speed and accelerator pedal opening, and the rotational speed and torque of the engine, etc.; transmitting a gearbox state acquisition request to the TCU to acquire gear information, and states, rotating speeds, torque and the like of the clutch; and sending a motor state acquisition request to the MCU to acquire the state, the rotating speed, the torque and the like of the motor.

In order to reduce the fuel consumption of the hybrid vehicle, it is preferable to start the engine with an electric motor. The HCU can first determine whether the motor can provide enough torque to start the engine based on the remaining charge of the high voltage battery and the battery temperature. Specifically, when the SOC of the high-voltage battery is not less than the charge threshold value and the battery temperature is not less than the temperature threshold value, the motor may be considered to have sufficient torque. It will be appreciated that the power threshold and the temperature threshold herein are different from the corresponding thresholds used to determine whether the motor needs to be started, and in a specific implementation, the power threshold and the temperature threshold used to determine the manner in which the engine is started may be less than the corresponding thresholds used to determine whether the motor needs to be started, respectively.

On the basis that the motor has enough torque, whether the vehicle is in a neutral state or not is judged according to gear information of the vehicle, and when the vehicle is in the neutral state, the motor is started under the neutral state. And when the vehicle is not in the neutral state, the vehicle can be considered to be in a normal running state. At this time, when the vehicle speed is in a low speed range (i.e., the vehicle speed is less than the vehicle speed threshold value) or the torque of the motor is insufficient, the starter start in running is performed. And when the vehicle speed is not less than the vehicle speed threshold value and the maximum starting torque of the motor is not less than the engine starting torque limit, starting the motor in running is performed.

When the vehicle is in a normal running state and the motor is required to start the engine, the power output by the motor is divided into a start part and a drive part, and in a low-speed state, the motor can interfere with the motor drive in the starting process of the engine, so that a driver has a sense of temporarily losing power due to the start of the engine, and the driving comfort is affected. In this case, starting the engine with the starter rather than starting the engine with the motor can improve the driving comfort. Similarly, since only a part of the output power of the motor can be used for starting the motor in the normal running state, the maximum electric drive power of the motor can be ensured to ensure the normal starting of the engine in addition to meeting the driving requirement of a driver.

The "maximum starting torque of the motor" in the present application may refer to a torque that the maximum electric drive power of the motor can provide in addition to meeting the driving demand of the driver. The maximum starting torque of the motor may be related to the remaining capacity of the high voltage battery and the battery temperature, as well as to vehicle speed, motor/engine speed, and accelerator pedal opening. The "engine starting torque limit" may refer to the minimum torque required for normal engine starting, and the engine starting torque limit may be a fixed value related to engine parameters and model.

The engine is started in neutral gear and is mainly applied to special working conditions, such as low temperature or insufficient motor capability. Specifically, when the SOC of the high-voltage battery is smaller than the electric quantity threshold value or the battery temperature is smaller than the temperature threshold value, whether the vehicle is in a neutral state is judged according to gear information of the vehicle, and when the vehicle is in the neutral state, engine starting under neutral is executed.

The electric quantity threshold, the temperature threshold, and the vehicle speed threshold in the present application may be fixed values that are predetermined. In some embodiments, after the HCU determines which starting mode is executed according to the remaining power of the high-voltage battery and the battery temperature, the gear information, the current vehicle speed and other related parameters, before the HCU sends an enabling signal to the corresponding TCU, MCU and other controllers to execute the corresponding starting mode, it is further required to determine whether the current driving mode of the vehicle has changed, and if the driving mode has changed, the related parameters are obtained again and the starting mode is determined. The drive mode includes an electric-only mode, a hybrid mode, and the like.

FIG. 3 is a flow chart illustrating motor start-up in neutral according to an exemplary embodiment. As shown in fig. 3, performing the neutral motor start includes:

s301, acquiring a clutch state, a clutch rotating speed and a motor rotating speed.

The clutch referred to hereinafter corresponds to the K0 clutch in fig. 1. Before the motor starts under the neutral gear, the engine and the clutch do not act, so that the engine is in an un-started state, and the K0 clutch is in an opened state. When a start of the neutral motor is initiated, the HCU may send an enable signal to the TCU to gradually engage the K0 clutch, thereby being in a torque controlled state. When the K0 clutch is in a torque control state, part of the torque of the motor can be output to the engine through the K0 clutch to drag the engine to rotate.

And the HCU can also send a gearbox state acquisition request to the TCU in real time so as to acquire gear information, the state of the clutch, the rotating speed, the torque and the like, and the HCU can judge whether the clutch is in a torque control state according to the clutch state fed back by the TCU. The HCU may obtain the motor speed by initiating a motor status acquisition request to the MCU. Similarly, the HCU may also control the state, speed, torque, etc. of the motor by sending an enable signal to the MCU.

In some embodiments, after the HCU sends the enable signal to the TCU for a period of time, if the HCU still does not detect that the clutch is in the torque control state, it may be that the clutch or the gearbox is malfunctioning, at which time the HCU may send an error signal to the overall vehicle controller and continue to send a gearbox state acquisition request.

S302, when the clutch is in a torque control state and the motor rotating speed is larger than the clutch rotating speed, the clutch is requested to be quickly combined.

The clutch status may be fed back to the HCU by the TCU. In a particular embodiment, the motor speed may be considered to be greater than the clutch speed when the motor speed is greater than the maximum speed in the inner and outer races of the clutch. When the motor is required to drag the engine to start, the HCU can start the motor through the MCU, so that the rotating speed of the motor is slightly increased, and the motor is ready for dragging the engine. When the motor rotation speed is detected to be larger than the clutch rotation speed, the fact that the clutch cannot fully transmit the starting torque of the motor at the moment is indicated, and therefore the clutch is controlled to be combined quickly, and starting efficiency of an engine is improved.

S303, acquiring the engine speed, and requesting the clutch to slide and grind when the engine speed is greater than the engine starting demand speed.

In a specific embodiment, the HCU may send a vehicle running state acquisition request to the ECU to perform acquisition of the engine speed. When the engine speed is higher than the engine starting demand speed, the engine can start autonomous oil injection ignition to increase the speed, and at the moment, the clutch can be slipped again to enable the clutch to gradually reach a closed state, so that the interference of the motor on the engine speed is gradually reduced, and the overrunning of the engine speed is prevented. The engine start demand rotational speed in the present application may be a preset fixed value, or the engine start demand rotational speed may be determined according to the water temperature of the engine circulating water.

S304, when the engine is in an operating state and the clutch is closed, the motor is requested to withdraw torque.

The engine status may be fed back to the HCU by the ECU. In particular embodiments, the engine may be considered to be in operation when the engine speed is greater than an engine start demand speed (i.e., a speed threshold). Alternatively, the engine may be considered to be in an operating state when the engine speed attains a speed threshold and the state continues for a certain period of time. When the engine is in a running state, the engine is considered to be started successfully, and the clutch is controlled to be closed at the moment so as to facilitate the engine to drive the motor to rotate for power generation, and the motor does not output torque to the engine any more.

Alternatively, when the engine speed is synchronized with the motor speed, the clutch is requested to be closed to ensure stable operation of the powertrain of the vehicle.

In a specific embodiment, the motor outputs torque at a speed above the engine start demand speed (i.e., speed threshold) to drive the engine to start, and when the engine speed reaches the speed threshold, the motor continues to output torque for a period of time until the engine speed is synchronized with the motor speed. When the engine speed is synchronous with the motor speed, the clutch is requested to be closed, so that power impact between the motor and the engine can be avoided.

Further, the HCU may continuously send and ECU send an engine start request to the TCU while performing the neutral motor start. When the engine is detected to be in an operating state, the engine start request is stopped from being sent. By continuously sending the engine start request, no other type of request signal is added in this way, and furthermore, whether the engine start process described above has failed can also be detected by continuously sending the request signal.

In the motor starting mode provided by the application, when the motor has enough torque under the neutral position, the motor drags the engine to start, and the engine sends idle torque under the neutral idle speed to charge the battery. Firstly, judging the actual gear and the clutch state, ensuring that the clutch is in a torque control state and then sending torque to the motor, enabling the clutch to act, and avoiding wasting the power output of the motor. When the synchronous rotation speeds of the engine and the motor are detected, the engine is in an operating state, the clutch is in a closed state, the motor withdraws torque, and the engine is started.

Fig. 4 is a flowchart illustrating motor start-up during travel according to an exemplary embodiment. As shown in fig. 4, performing the motor start during running includes:

s401, requesting clutch slipping.

Before the motor starts during running, the engine and the clutch do not act, so that the engine is in an un-started state, and the K0 clutch is in an opened state. When starting to perform motor start-up during running, the relationship between the wheel end target torque limit and the motor start-up maximum wheel end torque target may be first determined. That is, performing the motor start during running further includes: and calculating a wheel end target torque limit and a motor starting maximum wheel end torque target. The clutch slip is requested when the wheel end target torque limit is less than the motor start maximum wheel end torque target.

Wherein the wheel end target torque limit is operable to indicate a minimum wheel end torque required to maintain a current driving state of the vehicle; the motor start maximum wheel end torque target may be used to indicate the maximum wheel end torque that the motor may provide while dragging the engine start. When the end target torque limit is less than the motor start maximum wheel end torque target, the torque provided by the motor is considered sufficient to simultaneously start the engine and provide drive torque to ensure reliability of engine start and stability of vehicle travel.

In the step S204, the relationship between the maximum starting torque of the motor and the engine starting torque limit is determined, so that the step of determining the starting mode is matched, and whether the motor starting can be reliably performed in the running state of the current vehicle is further determined, thereby improving the reliability of the engine starting through redundancy determination.

In a specific embodiment, if the wheel end target torque limit is detected to be greater than the motor start maximum wheel end torque target, the detection signal is continued to be sent until the wheel end target torque limit is detected to be less than the motor start maximum wheel end torque target. The wheel end target torque limit is related to engine torque and gear.

When it is confirmed that the motor start-up can be reliably performed during running, the clutch is requested to be slipped, and the clutch is in a torque control state, so that part of the torque of the motor can be output to the engine through the K0 clutch to drag the engine to rotate.

S402, when the engine rotating speed and the motor rotating speed are synchronous, the clutch is requested to be closed.

In particular embodiments, the HCU may request engine status and clutch status from the ECU and TCU, respectively, and receive ECU feedback of engine status and TCU feedback of clutch status. Alternatively, the HCU may also acquire engine speed and motor speed and request clutch closure when the engine speed is synchronized with the motor speed and/or when the engine speed is greater than a skid control minimum engine speed to reduce power shock during driving. The minimum engine speed for the slip control in the present application may be a fixed value, and specifically may refer to a minimum value reached by the motor that may drag the engine when the clutch is in the slip control state. When the engine speed and the motor speed are synchronized, or the engine speed is greater than the slip control minimum engine speed, it can be considered that the engine is already in an operating state, at which time the clutch K0 is closed, and the torque of the engine can be output to the transmission. In particular embodiments, when the clutch is requested to close, the clutch may continue to slip (fast or slow) from the torque control state to the closed state.

Because there are two driving forces, namely the torque provided by the engine and the torque provided by the motor in the vehicle, the engine needs to be ensured to work in the area with the best comprehensive performance so as to reduce oil consumption and emission, and the wheel end torque provided by the engine can be adjusted by controlling the clutch to slide and grind.

S403, when the wheel end torques respectively provided by the engine and the motor are synchronized, the start is ended.

When the torque of the wheel end provided by the engine and the motor is synchronous, the torque can be better controlled, and a power system in the vehicle can realize stable power switching under the condition, and the engine is ensured to work in the area with the best comprehensive performance by adjusting the torque provided by the motor.

The motor starts in driving that this application provided is the engine start under the common operating mode, starts the engine through clutch closure when acceleration section or speed of a motor reaches certain limit value. Firstly, judging whether the torque limit of the wheel end can meet the starting requirement of a large motor, then executing the starting of an engine, and enabling a clutch to enter a torque control state. And the clutch is in a sliding grinding state after the rotation speed of the engine is synchronous with the rotation speed of the motor, when the engine is in a running state and the clutch is in a closing state, the wheel end torque provided by the engine and the motor is also synchronous, and the starting is finished at the moment.

Fig. 5 shows a flowchart of the start of the starter during driving according to an exemplary embodiment. As shown in fig. 5, performing the running starter start includes:

s501, starting a starter and requesting a clutch to slide and grind.

Before the motor starts during running, the engine and the clutch do not act, so that the engine is in an un-started state, and the K0 clutch is in an opened state. When starting the starter while running is started, the relationship between the maximum starting torque of the motor and the engine starting torque limit may be determined first. And through redundancy judgment, the reliability of engine starting is improved. When the maximum starting torque of the electric machine is less than the engine starting torque limit, the electric machine is considered not to be able to provide enough torque to pull the engine on. At this time, the starter is started, and the clutch is requested to be slipped, so that the clutch is in a torque control state, and thus the torque provided by the starter can be output to the engine through the K0 clutch to drag the engine to rotate. In particular embodiments, the starter may be integrated within the transmission.

S502, when the engine rotating speed and the motor rotating speed are synchronous, the clutch is requested to be closed.

In particular embodiments, the HCU may request engine status and clutch status from the ECU and TCU, respectively. When the engine speed is greater than the starter start demand speed, or the engine speed is synchronized with the motor speed, the engine may be considered to be in an operating state. When the engine speed and the motor speed are synchronized, the clutch slip film may be requested to gradually bring the clutch closer from the torque control state to the closed state until the clutch K0 is in the closed state, and the torque of the engine may be output to the transmission. Also, by controlling the clutch slip, the torque provided by the engine can be adjusted and the noise, vibration and harshness (Noise, vibration, harshness, NVH) of the vehicle can be improved.

S503, when the time of the engine in the running state reaches the preset time, starting is finished.

In order to determine that the engine has been successfully started and that the engine has achieved a successful and stable one-time operation, the start is ended when the time the engine is in the running state reaches a preset time. When the time that the engine is in the running state does not reach the preset time, the HCU still continuously transmits the engine start request.

The starter starting mode in the driving provided by the application is mainly used for a low-speed section, and when the torque of the motor is insufficient, the starter is used for driving the engine to start. Firstly, judging whether the motor torque is smaller than the torque limit supporting the starting of the engine, if so, enabling a starter to drive the engine to start, and enabling a clutch to be in a torque control state. When the rotating speed of the engine is larger than the set rotating speed or in the running state, the clutch is combined and slipped, and the engine is started and stopped after the engine keeps in the running state continuously.

Fig. 6 illustrates a flowchart of a neutral-down starter start according to an exemplary embodiment. As shown in fig. 6, performing the neutral-down starter start includes:

s601, acquiring an engine state and a clutch state.

Before the starter starts under neutral gear, the clutch can be controlled to be in an open state so as to isolate the engine from the motor and avoid power impact. And, an engine state is obtained, when the engine is in an inactive state, the HCU may request that the starter be enabled and that the clutch be slipping to be in a torque control state, so that torque provided by the starter may be output to the engine to drag the engine to rotate. While the engine is in a start state, the HCU may request that the clutch slip to be in a torque control state. Meanwhile, the HCU can also acquire the engine speed, and when the engine speed is greater than the starting demand speed or the engine speed is greater than a preset speed threshold, the engine can be considered to be in a running state.

S602, when the engine is in an operating state and the clutch is in a torque control state, requesting the starter to stop and requesting the clutch to be combined slowly.

When the engine is in an operating state, the starter may stop outputting power to the engine, and the clutch may be slowly engaged to output torque of the engine to the motor, and in the process, the engine may autonomously adjust its own rotation speed. By controlling the clutch to engage slowly, the NVH of the vehicle may be better improved. In a specific embodiment, the process of closing the clutch at a rate greater than a certain rate threshold may be referred to as clutch fast-engaging, and the process of closing the clutch at a rate less than the rate threshold may be referred to as clutch slow-engaging. And in some embodiments, the clutch slip film may be at a set rate threshold.

S603, acquiring the engine speed, and requesting the clutch to slide and grind when the engine speed is synchronous with the motor speed.

When the rotation speed of the engine is synchronous with the rotation speed of the motor, the clutch is requested to be slipped so that the clutch approaches to the closed state from the torque control state, and therefore the torque provided by the engine can be output to the motor, and the engine can conveniently drive the motor to rotate to generate electricity.

S604, when the clutch is in a closed state, starting is finished.

When the clutch is in the closed state, the torque provided by the engine may be considered to be fully output to the electric machine, at which point the HCU may stop cranking the engine start request to end the engine start-up process.

The starter starting mode under neutral gear is mainly used for starting an engine by a starter under special working conditions, such as low temperature or other conditions of insufficient motor capacity. Firstly, judging whether an engine is in a starting state, if not, judging that a clutch position is in an opening state and the vehicle is in a neutral gear condition, and enabling a starter. When the engine speed is higher than the set speed or in an operating state, the clutch is controlled to be combined and in a sliding mode, and when the clutch is in a closed state and the engine speed is synchronous with the motor speed, starting is finished.

The present application also provides an engine starting apparatus, as shown in fig. 7, comprising:

an acquisition module 701 configured to acquire a remaining power of a high-voltage battery in the vehicle and a battery temperature, gear information, and a current vehicle speed;

a judging module 702 configured to judge whether the vehicle is in a neutral state according to the gear information when the remaining power is not less than the power threshold and the battery temperature is not less than the temperature threshold;

an execution module 703 configured to execute a neutral motor start when the vehicle is in a neutral state; when the vehicle is not in a neutral state, the current vehicle speed is not less than a vehicle speed threshold value, and the maximum starting torque of the motor is not less than the engine starting torque limit, starting the motor in running; when the vehicle is not in a neutral state and the current vehicle speed is smaller than a vehicle speed threshold value or the maximum starting torque of the motor is smaller than the engine starting torque limit, starting the starter in running; and executing the start of the starter under neutral gear when the remaining electric quantity is smaller than the electric quantity threshold value or the battery temperature is smaller than the temperature threshold value and the vehicle is in the neutral gear state.

Optionally, the execution module is further configured to:

acquiring a clutch state, a clutch rotating speed and a motor rotating speed;

Optionally, the execution module is further configured to:

requesting a clutch slip mill;

requesting clutch closure when the engine speed and the motor speed are synchronized;

Optionally, the execution module is further configured to:

starting a starter and requesting a clutch slip film;

Optionally, the execution module is further configured to:

acquiring an engine state and a clutch state;

when the clutch is in the closed state, the start-up is ended.

The specific manner in which the various modules perform the operations in the apparatus of the above embodiments have been described in detail in connection with the embodiments of the method, and will not be described in detail herein.

It should be noted that: the engine starting device provided in the above embodiment is only exemplified by the division of the above functional modules, and in practical application, the above functional allocation may be performed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to perform all or part of the functions described above. In addition, the engine starting device provided in the above embodiment and the engine starting method embodiment belong to the same concept, and the specific implementation process is detailed in the method embodiment, which is not repeated here.

In this application, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "plurality" refers to two or more, unless explicitly defined otherwise.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the application pertains. The specification and examples are to be regarded in an illustrative manner only.

It is to be understood that the present application is not limited to the precise arrangements and instrumentalities shown in the drawings, which have been described above, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims

1. An engine starting method for an electric machine disposed at an input of a transmission and between the engine and the transmission, the electric machine and the engine having a first clutch therebetween, and the electric machine and the transmission having a hybrid architecture of a second clutch therebetween, the method comprising:

executing a neutral motor start when the vehicle is in the neutral state;

When the remaining power is less than a power threshold or the battery temperature is less than the temperature threshold, and the vehicle is in the neutral state, a neutral-down starter start is performed,

wherein said executing a neutral motor start comprises:

acquiring a clutch state, a clutch rotating speed and a motor rotating speed;

requesting the motor to withdraw torque when the engine is in an operating state and the clutch is in a closed state,

wherein the executing the motor start in running includes:

requesting a clutch slip mill;

when the wheel end torques respectively provided by the engine and the motor are synchronous, the starting is finished,

wherein the executing the starter start in the driving includes:

starting the starter and requesting the clutch to slide;

when the time that the engine is in the running state reaches the preset time, the starting is finished,

wherein said executing a neutral lower starter start comprises:

acquiring an engine state and a clutch state;

when the clutch is in a closed state, the start-up is ended.

2. An engine starting device for use with a hybrid architecture having an electric machine disposed at an input of a transmission and between the engine and the transmission, a first clutch between the electric machine and the engine, and a second clutch between the electric machine and the transmission, the device comprising:

the acquisition module is configured to acquire the residual capacity and the battery temperature of the high-voltage battery in the vehicle, gear information and the current vehicle speed;

an execution module configured to execute a neutral motor start when the vehicle is in the neutral state; when the vehicle is not in the neutral state, the current vehicle speed is not less than a vehicle speed threshold value, and the maximum starting torque of the motor is not less than the engine starting torque limit, starting the motor in running; executing starter starting in running when the vehicle is not in the neutral state and the current vehicle speed is smaller than a vehicle speed threshold value or the maximum starting torque of the motor is smaller than the engine starting torque limit; and when the remaining power is less than a power threshold or the battery temperature is less than the temperature threshold, and the vehicle is in the neutral state, performing a neutral-down starter start,

wherein said executing a neutral motor start comprises:

acquiring a clutch state, a clutch rotating speed and a motor rotating speed;

wherein the executing the motor start in running includes:

requesting a clutch slip mill;

wherein the executing the starter start in the driving includes:

starting the starter and requesting the clutch to slide;

wherein said executing a neutral lower starter start comprises:

acquiring an engine state and a clutch state;

when the clutch is in a closed state, the start-up is ended.