CN116255262B

CN116255262B - Engine cold start control method, device, computer equipment and storage medium

Info

Publication number: CN116255262B
Application number: CN202310266310.7A
Authority: CN
Inventors: 庄晓; 张小龙; 陈永瑞; 杨浩; 孙毅; 唐超; 王鹏
Original assignee: FAW Jiefang Automotive Co Ltd; FAW Jiefang Qingdao Automobile Co Ltd
Current assignee: FAW Jiefang Automotive Co Ltd; FAW Jiefang Qingdao Automobile Co Ltd
Priority date: 2023-03-20
Filing date: 2023-03-20
Publication date: 2024-12-03
Anticipated expiration: 2043-03-20
Also published as: CN116255262A

Abstract

The application relates to an engine cold start control method, an engine cold start control device, a computer device, a storage medium and a computer program product. The method comprises the steps of obtaining engine temperature, determining first reverse towing torque of a generator according to real-time engine speed and engine temperature in a first preset duration under the condition that a first preset relation is met between the engine temperature and a temperature threshold, controlling engine cold start based on the first reverse towing torque, the first preset speed, the current engine speed and idle speed, determining target speed of the engine according to battery electric quantity under the condition that a second preset relation is met between the engine temperature and the temperature threshold, determining second reverse towing torque of the generator according to the target speed and the current engine speed, and controlling engine cold start based on the second reverse towing torque, the current engine speed, the second preset speed and the target speed. The method can ensure that the engine is successfully started at low temperature.

Description

Engine cold start control method, device, computer equipment and storage medium

Technical Field

The present application relates to the field of vehicle control, and in particular, to an engine cold start control method, apparatus, computer device, storage medium, and computer program product.

Background

After the engine of the existing hybrid electric vehicle is reversely towed and started at a high rotating speed at normal temperature, an engine controller can maintain to operate at an idle speed by controlling the engine at an idle speed, and at a low temperature, the engine cannot maintain to operate at the idle speed by adopting the method of reversely towing and starting at the high rotating speed. Therefore, the conventional engine cold start control method of the hybrid vehicle has the problem that the engine is difficult to start successfully at low temperature.

Disclosure of Invention

Based on this, it is necessary to provide an engine cold start control method, an apparatus, a computer device, a computer readable storage medium and a computer program product capable of ensuring that an engine is cold started successfully at a low temperature, in order to solve the problem that the engine is difficult to start successfully at a low temperature in the conventional engine cold start control method.

In a first aspect, the present disclosure provides a method for controlling cold start of an engine. The method comprises the following steps:

Acquiring the temperature of an engine;

under the condition that a first preset relation is met between the temperature of the engine and a temperature threshold value, determining a speed change rate according to the real-time speed of the engine within a first preset duration; determining a first reverse dragging torque of the generator according to the temperature and the speed change rate of the engine, and controlling the cold start of the engine based on the first reverse dragging torque, a first preset speed, the current speed and the idle speed of the engine;

Under the condition that a second preset relation between the temperature of the engine and a temperature threshold value is met, acquiring the electric quantity of the battery and the current rotating speed of the engine, determining the target rotating speed of the engine according to the electric quantity of the battery, determining the second anti-dragging torque of the generator according to the target rotating speed and the current rotating speed of the engine, and controlling the cold start of the engine based on the second anti-dragging torque, the current rotating speed of the engine, the second preset rotating speed and the target rotating speed.

In one embodiment, controlling the engine cold start based on the second counter-drag torque, the current engine speed, the second preset speed, and the target speed includes:

controlling the generator to output a second anti-dragging torque, controlling the engine to continuously spray oil for ignition until the compression ignition of the engine is successful, controlling the engine to stop spraying oil for ignition, and controlling the generator to stop outputting the torque within a second preset time period;

And under the condition that the current rotating speed of the engine at any moment in the second preset time is larger than the second preset rotating speed, determining that the cold start of the engine is finished, wherein the second preset rotating speed is larger than the target rotating speed.

In one embodiment, after controlling the generator to output the second counter-drag torque, further comprising:

Opening an air inlet preheating switch when the current rotating speed of the engine is larger than a third preset rotating speed, wherein the third preset rotating speed is smaller than the second preset rotating speed;

And taking the time from the moment of controlling the generator to output the second anti-dragging torque to the moment of determining that the cold start of the engine is completed as cold start time, and closing the air inlet preheating switch under the condition that the cold start time exceeds a first time threshold.

In one embodiment, controlling the engine cold start based on the first counter-drag torque, the first preset rotational speed, the current rotational speed of the engine, and the idle rotational speed includes:

controlling the generator to output a first reverse dragging torque until the current rotating speed of the engine reaches a first preset rotating speed, and controlling the generator to stop torque output;

Under the condition that the current rotating speed of the engine is reduced to the idle rotating speed, determining the output torque of the engine according to the idle rotating speed, and controlling the engine to output corresponding output torque;

and determining that the cold start of the engine is completed when the duration of the output idle speed of the engine exceeds a second duration threshold.

In one embodiment, determining a first counter-drag torque of the generator based on the engine temperature and the rate of change of rotational speed includes:

Searching engine friction torque corresponding to the engine temperature in a first mapping relation, wherein the first mapping relation is used for representing the relation between the engine temperature and the engine friction torque;

searching a generator correction torque corresponding to the rotation speed change rate in a second mapping relation, wherein the second mapping relation is used for representing the relation between the rotation speed change rate and the generator correction torque;

a first counter-drag torque of the generator is determined based on the engine friction torque and the generator correction torque.

In one embodiment, determining a target rotational speed of the engine based on the battery level includes:

under the condition that the battery electric quantity is higher than the electric quantity threshold value, determining the target rotating speed of the engine as a fourth preset rotating speed;

And under the condition that the electric quantity of the battery is not higher than the electric quantity threshold value, determining the target rotating speed of the engine as a fifth preset rotating speed, wherein the fifth preset rotating speed is smaller than a fourth preset rotating speed, and the fourth preset rotating speed is smaller than the idle rotating speed.

In one embodiment, determining the second counter-drag torque of the generator based on the target rotational speed, the current rotational speed of the engine, includes:

Determining a speed difference according to the target speed and the current speed of the engine;

according to the rotation speed difference, determining the correction torque of the generator through proportional integral control;

Searching a generator feedforward torque corresponding to the target rotating speed in a third mapping relation, wherein the third mapping relation is used for representing the relation between the target rotating speed and the generator feedforward torque;

a second counter-drag torque of the generator is determined based on the generator feed-forward torque and the generator correction torque.

In a second aspect, the application also provides an engine cold start control device. The device comprises:

the acquisition module is used for acquiring the temperature of the engine;

The first control module is used for determining a speed change rate according to the real-time speed of the engine within a first preset duration under the condition that a first preset relation is met between the temperature of the engine and a temperature threshold value;

The second control module is used for acquiring the battery electric quantity and the current rotating speed of the engine under the condition that a second preset relation between the temperature of the engine and the temperature threshold value is met, determining the target rotating speed of the engine according to the battery electric quantity, determining the second anti-dragging torque of the generator according to the target rotating speed and the current rotating speed of the engine, and controlling the cold start of the engine based on the second anti-dragging torque, the current rotating speed of the engine, the second preset rotating speed and the target rotating speed.

In a third aspect, the present application also provides a computer device. The computer device comprises a memory storing a computer program and a processor which when executing the computer program performs the steps of:

Acquiring the temperature of an engine;

In a fourth aspect, the present application also provides a computer-readable storage medium. The computer readable storage medium having stored thereon a computer program which when executed by a processor performs the steps of:

Acquiring the temperature of an engine;

In a fifth aspect, the present application also provides a computer program product. The computer program product comprises a computer program which, when executed by a processor, implements the steps of:

Acquiring the temperature of an engine;

The engine cold start control method, the device, the computer equipment, the storage medium and the computer program product are used for determining a speed change rate according to the real-time engine speed within a first preset duration when a first preset relation is met between the engine temperature and a temperature threshold value by acquiring the engine temperature, determining first reverse towing torque of a generator according to the engine temperature and the speed change rate, controlling engine cold start based on the first reverse towing torque, the first preset speed, the current engine speed and the idle speed, acquiring battery electric quantity and the current engine speed when a second preset relation is met between the engine temperature and the temperature threshold value, determining the target engine speed according to the battery electric quantity, determining second reverse towing torque of the generator according to the target engine speed and the current engine speed, and controlling engine cold start based on the second reverse towing torque, the current engine speed, the second preset speed and the target speed. According to the method for determining the reverse dragging torque of the different generators under different temperature conditions according to the rotating speed condition of the engine and the electric quantity of the battery, the generators can be controlled to output the corresponding reverse dragging torque under different temperature conditions, and therefore the engine can be successfully started at low temperature.

Drawings

FIG. 1 is an application environment diagram of an engine cold start control method in one embodiment;

FIG. 2 is a flow chart of a method of engine cold start control in one embodiment;

FIG. 3 is a schematic flow chart of a sub-process of S206 in one embodiment;

FIG. 4 is a schematic flow chart of the sub-process of S204 in one embodiment;

FIG. 5 is a schematic diagram of a sub-process of S204 in another embodiment;

FIG. 6 is a schematic diagram of a hybrid system in an embodiment;

FIG. 7 is a general flow diagram of an engine cold start control method in one embodiment;

FIG. 8 is a block diagram of an engine cold start control device according to one embodiment;

fig. 9 is an internal structural diagram of a computer device in one embodiment.

Detailed Description

The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

The engine cold start control method provided by the embodiment of the application can be applied to an application environment shown in fig. 1. Wherein the controller 102 communicates with the engine 104 via a network. The controller 102 obtains an engine temperature, determines a speed change rate according to an engine real-time speed within a first preset time period when a first preset relation is satisfied between the engine temperature and a temperature threshold value, determines a first counter-drag torque of the generator according to the engine temperature and the speed change rate, controls engine cold start based on the first counter-drag torque, the first preset speed, a current engine speed and an idle speed, obtains a battery power and the current engine speed when a second preset relation is satisfied between the engine temperature and the temperature threshold value, determines a target speed of the engine according to the battery power, determines a second counter-drag torque of the generator according to the target speed and the current engine speed, and controls engine cold start based on the second counter-drag torque, the current engine speed, the second preset speed and the target speed. The controller 102 may be, but not limited to, various personal computers, notebook computers, smart phones, tablet computers, internet of things devices, and portable wearable devices, where the internet of things devices may be smart speakers, smart televisions, smart air conditioners, smart vehicle devices, and the like. The portable wearable device may be a smart watch, smart bracelet, headset, or the like.

In one embodiment, as shown in fig. 2, an engine cold start control method is provided, and the method is applied to the controller 102 in fig. 1 for illustration, and includes the following steps:

s202, acquiring the engine temperature.

The engine may be an engine of a planetary hybrid vehicle. The hybrid vehicle can work in a series hybrid power mode or a parallel hybrid power mode, and is a combination of the two modes. The engine temperature may refer to the temperature inside the engine's internal circulation water channel. In some embodiments, the controller may also acquire the ambient temperature. And replacing the engine temperature with the ambient temperature to perform subsequent engine cold start control.

S204, under the condition that a first preset relation is met between the temperature of the engine and a temperature threshold value, determining a speed change rate according to the real-time speed of the engine within a first preset time period, determining a first anti-dragging torque of the generator according to the temperature of the engine and the speed change rate, and controlling cold start of the engine based on the first anti-dragging torque, the first preset speed, the current speed of the engine and the idle speed.

The first preset relationship may be that the engine temperature is greater than a temperature threshold, or that the engine temperature is equal to the temperature threshold. Under the condition that a first preset relation is met between the temperature of the engine and the temperature threshold value, the controller determines the speed change rate according to the real-time speed of the engine within a first preset time period. The rate of change of rotational speed is used to indicate a change in rotational speed of the engine over a first predetermined period of time. The difference between the real-time engine speed at the cut-off time and the real-time engine speed at the start time in the first preset time period is obtained, and the ratio of the difference to the first preset time period is taken as the speed change rate.

The controller determines a first counter-drag torque of the generator based on the engine temperature and the rate of change of rotational speed. The generator outputs a first counter-drag torque to counter-drag the engine start. Idle speed refers to the speed at which the engine is operating in neutral. The controller controls the engine to be cold started based on the first reverse torque, the first preset rotating speed, the current rotating speed of the engine and the idle rotating speed.

S206, under the condition that a second preset relation is met between the temperature of the engine and the temperature threshold value, acquiring the electric quantity of the battery and the current rotating speed of the engine, determining the target rotating speed of the engine according to the electric quantity of the battery, determining the second anti-dragging torque of the generator according to the target rotating speed and the current rotating speed of the engine, and controlling the cold start of the engine based on the second anti-dragging torque, the current rotating speed of the engine, the second preset rotating speed and the target rotating speed.

Wherein the second preset relationship may be that the engine temperature is less than a temperature threshold, or that the engine temperature is equal to a temperature threshold. And under the condition that the second preset relation is met between the temperature of the engine and the temperature threshold value, the controller acquires the battery electric quantity and the current rotating speed of the engine, and determines the target rotating speed of the engine according to the battery electric quantity. In some embodiments, the controller presets a mapping relationship between the battery power and the target rotational speed of the engine, and the controller can determine the target rotational speed of the engine under various battery powers.

The controller determines a second counter-drag torque of the generator based on the target rotational speed and the current rotational speed of the engine. The generator outputs a second counter-drag torque to counter-drag the engine start. The controller controls the engine to be cold started based on the second reverse torque, the current engine speed, the second preset speed and the target speed.

The engine cold start control method comprises the steps of obtaining engine temperature, determining a speed change rate according to real-time engine speeds in a first preset time period when a first preset relation is met between the engine temperature and a temperature threshold value, determining first anti-dragging torque of a generator according to the engine temperature and the speed change rate, controlling engine cold start based on the first anti-dragging torque, the first preset speed, the current engine speed and an idle speed, obtaining battery electric quantity and the current engine speed when a second preset relation is met between the engine temperature and the temperature threshold value, determining target engine speeds according to the battery electric quantity, determining second anti-dragging torque of the generator according to the target engine speeds and the current engine speed, and controlling engine cold start based on the second anti-dragging torque, the current engine speed, the second preset speed and the target speed. According to the method for determining the reverse dragging torque of the different generators under different temperature conditions according to the rotating speed condition of the engine and the electric quantity of the battery, the generators can be controlled to output the corresponding reverse dragging torque under different temperature conditions, and therefore the engine can be successfully started at low temperature.

In one embodiment, as shown in FIG. 3, controlling the engine cold start based on the second counter-drag torque, the current engine speed, the second preset speed, and the target speed includes:

S302, controlling the generator to output a second anti-dragging torque, controlling the engine to continuously spray oil and ignite until the compression ignition of the engine is successful, controlling the engine to stop spraying oil and igniting, and controlling the generator to stop outputting the torque within a second preset time.

The controller controls the generator to output second anti-dragging torque and controls the engine to continuously spray oil and ignite until compression ignition of the engine is successful. And when the compression ignition is successful, the controller determines that the compression ignition of the engine is successful according to a sign signal of the successful compression ignition. And when compression ignition of the engine is successful, the controller controls the engine to stop oil injection and ignition, and controls the generator to stop outputting torque within a second preset time period. And when the engine stops oil injection and ignition, the rotation speed of the engine is continuously reduced from the rotation speed peak value within a second preset duration of stopping the output torque of the generator.

S304, determining that the cold start of the engine is finished when the current rotation speed of the engine at any moment in the second preset time is larger than the second preset rotation speed, wherein the second preset rotation speed is larger than the target rotation speed.

And determining that the cold start of the engine is finished under the condition that the current rotating speed of the engine at any moment in the second preset time period is larger than the second preset rotating speed. That is, the engine continues to move at a rotational speed greater than the second preset rotational speed for a second preset duration, and the controller determines that the cold start of the engine is complete. The second preset rotational speed is greater than the target rotational speed.

In this embodiment, the generator is controlled to output the second reverse towing torque, and the engine is controlled to continuously spray oil and ignite until the compression ignition of the engine succeeds, so that the engine speed can be increased to a higher speed value, and the completion of the cold start of the engine is determined under the condition that the current speed of the engine at any time within the second preset time is greater than the second preset speed, so that the success of the reverse towing start of the engine can be ensured.

In one embodiment, after the generator is controlled to output the second anti-drag torque, the method further comprises the steps of opening an air inlet preheating switch when the current rotating speed of the engine is larger than a third preset rotating speed, wherein the third preset rotating speed is smaller than the second preset rotating speed, taking the time period from the moment of controlling the generator to output the second anti-drag torque to the moment of determining that the cold start of the engine is completed as cold start time period, and closing the air inlet preheating switch when the cold start time period exceeds a first time period threshold value.

When the engine is reversely towed and started at a low temperature, the engine is often required to be preheated in air. After the generator is controlled to output the second reverse traction torque, when the current rotating speed of the engine is increased to a third preset rotating speed, the controller controls the air inlet preheating switch, so that the engine is preheated, and smooth start of cold start is facilitated.

The controller takes the time period from the moment of controlling the generator to output the second anti-dragging torque to the moment of determining that the cold start of the engine is completed as the cold start time period. And under the condition that the cold start time length exceeds the first time length threshold value, the air inlet preheating switch is controlled to be closed, so that continuous heating is avoided, and the engine is prevented from being damaged.

In this embodiment, after the generator is controlled to output the second reverse traction torque, the air inlet preheating switch is turned on to preheat the engine when the current rotation speed of the engine is greater than the third preset rotation speed, so that smooth completion of cold start is facilitated, and the air inlet preheating switch is turned off when the cold start duration exceeds the first duration threshold value, so that continuous heating is avoided and the engine is damaged.

In one embodiment, as shown in FIG. 4, controlling the engine cold start based on the first counter-drag torque, the first preset rotational speed, the current rotational speed of the engine, and the idle rotational speed includes:

S402, controlling the generator to output first anti-dragging torque until the current rotating speed of the engine reaches a first preset rotating speed, and controlling the generator to stop torque output, wherein the first preset rotating speed is larger than the idle rotating speed.

The controller controls the generator to output a first reverse torque until the current rotating speed of the engine reaches a first preset rotating speed. And the rotating speed of the engine is continuously increased along with the first anti-dragging torque output of the generator, and the generator is controlled to stop the torque output when the current rotating speed of the engine reaches a first preset rotating speed. As the torque of the generator stops being output, the rotational speed of the engine is continuously reduced from the first preset rotational speed. The first preset rotating speed is larger than the idle rotating speed, so that the engine is favorable for successful cold start.

S404, under the condition that the current rotating speed of the engine is reduced to the idle rotating speed, determining the output torque of the engine according to the idle rotating speed, and controlling the engine to output corresponding output torque, wherein the output torque is used for controlling the engine to output the idle rotating speed.

Wherein, as the engine speed decreases, the controller determines the output torque of the engine according to the idle speed when the current engine speed is about to be at the idle speed. That is, after the generator stops outputting torque, the engine is required to continue outputting torque in order to maintain the engine to continue running at the idle speed. The controller controls the engine to output a corresponding output torque at the idle speed to instruct the engine to continue operating at the idle speed.

S406, determining that the cold start of the engine is completed when the duration of the output idle speed of the engine exceeds a second duration threshold.

The controller obtains the duration of the engine running at the idle speed, and determines that the cold start of the engine is completed under the condition that the duration of the engine output idle speed exceeds a second duration threshold.

In the embodiment, the first counter-drag torque is output by controlling the generator until the current rotating speed of the engine reaches the first preset rotating speed, the rotating speed of the engine can be guaranteed to be increased to a higher rotating speed value, the output torque of the engine is determined according to the idle rotating speed under the condition that the current rotating speed of the engine is reduced to the idle rotating speed, the corresponding output torque is output by controlling the engine, and the cold start of the engine is determined to be completed under the condition that the duration of the idle rotating speed output by the engine exceeds the second duration threshold value, so that the smooth cold start of the engine can be guaranteed to be completed.

In one embodiment, as shown in FIG. 5, determining the first counter-drag torque of the generator based on the engine temperature and the rate of change of rotational speed includes:

s502, searching engine friction torque corresponding to the engine temperature in a first mapping relation, wherein the first mapping relation is used for representing the relation between the engine temperature and the engine friction torque.

S504, searching a generator correction torque corresponding to the rotation speed change rate in a second mapping relation, wherein the second mapping relation is used for representing the relation between the rotation speed change rate and the generator correction torque;

S506, determining the first anti-drag torque of the generator according to the engine friction torque and the generator correction torque.

According to historical experimental data, a first mapping relation representing the relation between the engine temperature and the engine friction torque and a second mapping relation representing the relation between the rotating speed change rate and the generator correction torque are determined. The controller searches engine friction torque corresponding to the engine temperature in the first mapping relation, and searches generator correction torque corresponding to the rotating speed change rate in the second mapping relation. For engine temperatures not in the first map, a linear interpolation method may be employed to obtain engine friction torque at the corresponding engine temperature. Likewise, for the rotation speed change rate not in the second mapping relationship, a linear interpolation method may be adopted to obtain the generator correction torque at the corresponding rotation speed change rate.

And the controller brings the friction torque of the engine and the correction torque of the generator into a first counter-drag torque calculation formula to obtain the first counter-drag torque of the generator. The first counter drag torque calculation formula is as follows:

Where k is a planet row characteristic parameter, Δadd represents generator correction torque, T _ef represents engine friction torque, and T _1h represents first counter-drag torque.

In this embodiment, the engine friction torque corresponding to the engine temperature and the generator correction torque corresponding to the rotation speed change rate are searched in the mapping relation, so that the acquisition efficiency of the first anti-dragging torque of the engine is improved, the first anti-dragging torque of the generator is obtained based on the engine temperature and the rotation speed change rate, the corresponding anti-dragging torque of the generator is determined under the conditions of different temperatures and different rotation speeds of the engine, and the success of the start of the anti-dragging engine is facilitated.

In one embodiment, the target rotating speed of the engine is determined according to the battery electric quantity, wherein the target rotating speed of the engine is determined to be a fourth preset rotating speed under the condition that the battery electric quantity is higher than an electric quantity threshold value, and is determined to be a fifth preset rotating speed under the condition that the battery electric quantity is not higher than the electric quantity threshold value, and the fifth preset rotating speed is smaller than the fourth preset rotating speed, and the fourth preset rotating speed is smaller than the idle rotating speed.

The method comprises the steps of determining a target rotating speed of an engine to be a fourth preset rotating speed under the condition that battery electric quantity is higher than an electric quantity threshold value, determining the target rotating speed of the engine to be a fifth preset rotating speed under the condition that the battery electric quantity is not higher than the electric quantity threshold value, wherein the fifth preset rotating speed is smaller than the fourth preset rotating speed, and the fourth preset rotating speed is smaller than an idle rotating speed.

In this embodiment, the higher preset rotation speed is adopted as the target rotation speed under the condition of higher electric quantity, and the lower preset rotation speed is adopted as the target rotation speed under the condition of lower electric quantity, so that smooth cold start of the engine under low temperature is facilitated.

In one embodiment, the second anti-dragging torque of the generator is determined according to the target rotating speed and the current rotating speed of the engine, the generator correction torque is determined according to the rotating speed difference through proportional integral control, the generator feedforward torque corresponding to the target rotating speed is searched in a third mapping relation, the third mapping relation is used for representing the relation between the target rotating speed and the generator feedforward torque, and the second anti-dragging torque of the generator is determined according to the generator feedforward torque and the generator correction torque.

The controller makes a difference between the target rotating speed and the current rotating speed of the engine to obtain a rotating speed difference. And determining the corrected torque of the generator through proportional integral control according to the rotation speed difference. The determination formula of the correction torque of the generator is as follows:

Where T _adj denotes a generator correction torque, K _d denotes a proportional coefficient, K _i denotes an integral coefficient, and Δ _e denotes a rotational speed difference.

And determining a third mapping relation representing the relation between the target rotating speed and the feedforward torque of the generator according to historical experimental data. And the controller searches the feedforward torque of the generator corresponding to the target rotating speed in the third mapping relation. And adding the generator feedforward torque and the generator correction torque to obtain a second anti-drag torque of the generator. In some embodiments, the generator feed-forward torque and the speed difference are brought into a second counter-drag torque calculation formula to obtain a second counter-drag torque of the generator. The second counter-drag torque calculation formula is as follows:

Wherein T _set represents the second counter-drag torque, T _lead represents the generator feed-forward torque, K _d represents the proportionality coefficient, K _i represents the integral coefficient, and Δ _e represents the rotational speed difference.

In this embodiment, the speed difference is determined by the target speed and the current speed of the engine, and the feedforward torque of the generator corresponding to the target speed is found in the third mapping relationship, so as to obtain the second anti-drag torque of the generator.

To describe the engine cold start control method of the present embodiment in detail, the following describes one of the most detailed embodiments:

An application scenario of engine cold start control for a series-parallel hybrid power system is shown in fig. 6, which is a schematic diagram of a composition structure of the series-parallel hybrid power system. The series-parallel hybrid power system comprises an engine, a generator MG1, a main driving motor MG2, a planet row PG1 and a system output shaft. Fig. 7 is a general flow chart of the engine cold start control method.

First, judging a starting mode:

1.1 if the ambient temperature or the engine water temperature is higher than a temperature threshold, for example, the engine water temperature is 5 ℃, a high-rotation-speed reverse towing mode is adopted, the first reverse towing torque of the generator is calculated by 2.1, and the exiting reverse towing starting condition is judged by 3.1.

1.2, If the ambient temperature or the engine water temperature is lower than a temperature threshold, for example, the engine water temperature is 0 ℃, a low-rotation-speed reverse-dragging mode is adopted, the target rotation speed of the engine is judged by the battery electric quantity, if the battery electric quantity is higher than the electric quantity threshold, for example, the battery electric quantity is 30%, the reverse-dragging is maintained at 600rpm by adopting a fourth preset rotation speed, which is lower than the idle rotation speed of the engine by 800rpm, and if the battery electric quantity is lower than the electric quantity threshold, for example, the battery electric quantity is 20%, the reverse-dragging is maintained at 400rpm by adopting a fifth preset rotation speed, which is lower than the fourth preset rotation speed.

And 1.3, when the engine is started in the low-rotation-speed reverse-dragging mode, enabling the air inlet preheating function when the current rotation speed of the engine is greater than the third preset rotation speed of 50rpm, and stopping the air inlet preheating function if the cold start of the engine is successful and the cold start time exceeds the first time threshold for 5 s.

Step two, calculating the reverse dragging torque of the generator:

2.1, if a high-rotation-speed reverse-dragging starting mode is adopted, the friction torque of the engine is obtained through interpolation calculation according to the temperature of the engine, and a first reverse-dragging torque calculation formula of the generator is as follows:

2.2, If the low-rotation-speed anti-dragging starting mode is adopted, firstly, calculating a feedforward torque Tlead according to a target rotation speed, then calculating a rotation speed difference delta e according to the target rotation speed of the engine and the current rotation speed of the engine, and calculating a generator correction torque Tadj, wherein a second anti-dragging torque calculation formula is as follows:

2.3 If the high-speed reverse towing mode is adopted for starting, when the first reverse towing torque is released and the engine speed is reduced to the vicinity of the idle speed, the engine speed is maintained by the engine idle speed control. If the engine is started by adopting the low-rotation-speed reverse towing, in the second reverse towing torque application process, the engine is injected simultaneously to try to ignite, and the engine is continuously injected until the compression ignition of the engine is successful.

Thirdly, judging the exit reverse towing starting condition:

And 3.1, if the high-rotation-speed reverse towing mode is adopted, when the current rotation speed of the engine exceeds a first preset rotation speed, for example, the first preset rotation speed is 1200rpm, and the successful signal of the cold start of the engine is received, the completion of the cold start of the engine is determined, the whole vehicle controller controls the generator to release the reverse towing torque, and the high-rotation-speed reverse towing mode is exited.

And 3.2, if the low-rotation-speed reverse-dragging mode is adopted, the whole vehicle controller judges that the current rotation speed of the engine is higher than a second preset rotation speed, for example, the second preset rotation speed is 700rpm, the stop output torque of the generator exceeds the second preset time period for 5s, the cold start of the engine is considered to be completed, and if the cold start of the engine is considered to be failed within a third preset time period, for example, the third preset time period is 60s, the cold start of the engine is considered to be unsuccessful, and the low-rotation-speed reverse-dragging mode is exited. The third preset time period is longer than the second preset time period.

The engine cold start control method comprises the steps of obtaining engine temperature, determining a speed change rate according to real-time engine speeds in a first preset time period when a first preset relation is met between the engine temperature and a temperature threshold, determining first anti-dragging torque of a generator according to the engine temperature and the speed change rate, controlling engine cold start based on the first anti-dragging torque, the first preset speed, the current engine speed and an idle speed, obtaining battery electric quantity and the current engine speed when a second preset relation is met between the engine temperature and the temperature threshold, determining target engine speeds according to the battery electric quantity, determining second anti-dragging torque of the generator according to the target engine speeds and the current engine speed, and controlling engine cold start based on the second anti-dragging torque, the current engine speed, the second preset speed and the target speed. According to the method for determining the reverse dragging torque of the different generators under different temperature conditions according to the rotating speed condition of the engine and the electric quantity of the battery, the generators can be controlled to output the corresponding reverse dragging torque under different temperature conditions, and therefore the engine can be successfully started at low temperature. When the ambient temperature or the engine water temperature is higher, the engine speed is reversely dragged to a high speed by adopting a high-speed reverse dragging mode, and then the first reverse dragging torque is released. And when the current rotating speed of the engine is close to the idling speed, the engine resumes oil injection, and the reverse dragging start of the engine is realized. When the ambient temperature or the water temperature of the engine is low, the target rotating speed of the engine is firstly judged according to the electric quantity of the battery. And then the generator outputs a second anti-dragging torque to drive the engine to rotate around the target rotating speed, and simultaneously the fuel injector is controlled to spray fuel until the compression ignition is successful. After compression ignition is successful, the rotation speed of the engine is automatically increased, and the whole vehicle controller determines whether the starting is successful in the low-rotation-speed reverse towing mode according to the current rotation speed of the engine and the output torque of the generator.

It should be understood that, although the steps in the flowcharts related to the embodiments described above are sequentially shown as indicated by arrows, these steps are not necessarily sequentially performed in the order indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least some of the steps in the flowcharts described in the above embodiments may include a plurality of steps or a plurality of stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of the steps or stages is not necessarily performed sequentially, but may be performed alternately or alternately with at least some of the other steps or stages.

Based on the same inventive concept, the embodiment of the application also provides an engine cold start control device for realizing the engine cold start control method. The implementation of the solution provided by the device is similar to that described in the above method, so the specific limitation in the embodiments of the cold start control device for an engine provided below may be referred to the limitation of the cold start control method for an engine hereinabove, and will not be repeated here.

In one embodiment, as shown in FIG. 8, an engine cold start control apparatus 100 is provided, comprising an acquisition module 120, a first control module 140, and a second control module 160, wherein:

an acquisition module 120 for acquiring an engine temperature;

the first control module 140 is configured to determine a speed change rate according to an engine real-time speed within a first preset duration when a first preset relationship between an engine temperature and a temperature threshold is satisfied;

The second control module 160 is configured to obtain a battery power and a current engine speed when a second preset relationship between the engine temperature and a temperature threshold is satisfied, determine a target engine speed according to the battery power, determine a second anti-drag torque of the generator according to the target engine speed and the current engine speed, and control a cold start of the engine based on the second anti-drag torque, the current engine speed, the second preset engine speed, and the target engine speed.

The engine cold start control device is used for determining a speed change rate according to an engine real-time speed within a first preset duration under the condition that a first preset relation is met between the engine temperature and a temperature threshold value by acquiring the engine temperature, determining a first anti-dragging torque of a generator according to the engine temperature and the speed change rate, controlling engine cold start based on the first anti-dragging torque, the first preset speed, the current engine speed and an idle speed, acquiring battery electric quantity and the current engine speed under the condition that a second preset relation is met between the engine temperature and the temperature threshold value, determining a target speed of the engine according to the battery electric quantity, determining a second anti-dragging torque of the generator according to the target speed and the current engine speed, and controlling engine cold start based on the second anti-dragging torque, the current engine speed, the second preset speed and the target speed. According to the method for determining the reverse dragging torque of the different generators under different temperature conditions according to the rotating speed condition of the engine and the electric quantity of the battery, the generators can be controlled to output the corresponding reverse dragging torque under different temperature conditions, and therefore the engine can be successfully started at low temperature.

In one embodiment, the engine cold start is controlled based on the second reverse torque, the current engine speed, the second preset speed and the target speed, and the second control module 160 is further configured to control the generator to output the second reverse torque, control the engine to continuously spray fuel and ignite until the compression ignition of the engine succeeds, control the engine to stop spraying fuel and ignite, and control the generator to stop outputting torque within a second preset time period, and determine that the engine cold start is completed when the current engine speed at any time within the second preset time period is greater than the second preset speed, and the second preset speed is greater than the target speed.

In one embodiment, the second control module 160 is further configured to turn on the intake preheating switch when the current rotational speed of the engine is greater than a third preset rotational speed, the third preset rotational speed is less than the second preset rotational speed, and turn off the intake preheating switch when the cold start duration exceeds the first time threshold after determining a duration between a time when the generator is controlled to output the second counter-drag torque and a time when the engine is determined to be cold started.

In one embodiment, the first control module 140 is further configured to control the generator to output a first counter-drag torque based on the first counter-drag torque, a first preset speed, a current engine speed, and an idle speed, control the generator to stop torque output until the current engine speed reaches the first preset speed, the first preset speed is greater than the idle speed, determine an output torque of the engine based on the idle speed when the current engine speed decreases to the idle speed, control the engine to output a corresponding output torque, control the engine to output the idle speed when the duration of the engine to output the idle speed exceeds a second duration threshold, and determine that the engine cold start is complete.

In one embodiment, the first control module 140 is further configured to determine a first anti-drag torque of the generator according to the engine temperature and the rate of change of the rotational speed, search for an engine friction torque corresponding to the engine temperature in a first mapping relationship, the first mapping relationship is used for representing a relationship between the engine temperature and the engine friction torque, search for a generator correction torque corresponding to the rate of change of the rotational speed in a second mapping relationship, the second mapping relationship is used for representing a relationship between the rate of change of the rotational speed and the generator correction torque, and determine the first anti-drag torque of the generator according to the engine friction torque and the generator correction torque.

In one embodiment, the second control module 160 is further configured to determine, based on the battery level, a target speed of the engine, where the target speed is determined to be a fourth preset speed if the battery level is above the level threshold, and determine, where the fifth preset speed is less than the fourth preset speed, where the fourth preset speed is less than the idle speed if the battery level is not above the level threshold.

In one embodiment, the second control module 160 is further configured to determine a second anti-drag torque of the generator according to the target rotational speed and the current rotational speed of the engine, determine a rotational speed difference according to the target rotational speed and the current rotational speed of the engine, determine a generator correction torque according to the rotational speed difference through proportional integral control, find a generator feedforward torque corresponding to the target rotational speed in a third mapping relationship, wherein the third mapping relationship is used for representing a relationship between the target rotational speed and the generator feedforward torque, and determine the second anti-drag torque of the generator according to the generator feedforward torque and the generator correction torque.

The above-described respective modules in the engine cold start control apparatus may be implemented in whole or in part by software, hardware, and a combination thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.

In one embodiment, a computer device is provided, which may be a terminal, and the internal structure thereof may be as shown in fig. 9. The computer device includes a processor, a memory, an input/output interface, a communication interface, a display unit, and an input means. The processor, the memory and the input/output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input/output interface. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input/output interface of the computer device is used to exchange information between the processor and the external device. The communication interface of the computer device is used for carrying out wired or wireless communication with an external terminal, and the wireless mode can be realized through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. The computer program when executed by a processor implements a method of engine cold start control.

It will be appreciated by persons skilled in the art that the architecture shown in fig. 9 is merely a block diagram of some of the architecture relevant to the present inventive arrangements and is not limiting as to the computer device to which the present inventive arrangements are applicable, and that a particular computer device may include more or fewer components than shown, or may combine some of the components, or have a different arrangement of components.

In one embodiment, a computer device is provided comprising a memory and a processor, the memory having stored therein a computer program, the processor when executing the computer program performing the steps of:

The method comprises the steps of obtaining engine temperature, determining a speed change rate according to real-time engine speeds within a first preset time period under the condition that a first preset relation is met between the engine temperature and a temperature threshold value, determining first reverse towing torque of a generator according to the engine temperature and the speed change rate, controlling engine cold start based on the first reverse towing torque, the first preset speed, the current engine speed and an idle speed, obtaining battery electric quantity and the current engine speed under the condition that a second preset relation is met between the engine temperature and the temperature threshold value, determining target engine speeds according to the battery electric quantity, determining second reverse towing torque of the generator according to the target engine speeds and the current engine speed, and controlling the engine cold start based on the second reverse towing torque, the current engine speed, the second preset speed and the target speed.

In one embodiment, the processor when executing the computer program further performs the steps of:

And controlling the generator to output a second reverse towing torque, controlling the engine to continuously spray oil and ignite until the compression ignition of the engine is successful, controlling the engine to stop spraying oil and igniting, and controlling the generator to stop outputting the torque within a second preset time, and determining that the cold start of the engine is completed under the condition that the current rotating speed of the engine at any moment within the second preset time is larger than the second preset rotating speed, wherein the second preset rotating speed is larger than the target rotating speed.

Opening an air inlet preheating switch under the condition that the current rotating speed of the engine is larger than a third preset rotating speed; and taking the time from the moment when the generator is controlled to output the second reverse dragging torque to the moment when the cold start of the engine is determined to be completed as cold start time, and closing the air inlet preheating switch under the condition that the cold start time exceeds a first time threshold value.

the method comprises the steps of controlling a generator to output first reverse dragging torque until the current rotating speed of the engine reaches a first preset rotating speed, controlling the generator to stop torque output, enabling the first preset rotating speed to be larger than an idle rotating speed, determining output torque of the engine according to the idle rotating speed when the current rotating speed of the engine is reduced to the idle rotating speed, controlling the engine to output corresponding output torque, controlling the engine to output the idle rotating speed when the current rotating speed of the engine is reduced to the idle rotating speed, and determining that cold starting of the engine is completed when the duration of the idle rotating speed of the engine exceeds a second duration threshold.

The method comprises the steps of searching engine friction torque corresponding to engine temperature in a first mapping relation, searching generator correction torque corresponding to a rotating speed change rate in a second mapping relation, and determining first anti-tugging torque of a generator according to the engine friction torque and the generator correction torque.

And determining the target rotating speed of the engine as a fourth preset rotating speed under the condition that the battery electric quantity is higher than the electric quantity threshold value, and determining the target rotating speed of the engine as a fifth preset rotating speed under the condition that the battery electric quantity is not higher than the electric quantity threshold value, wherein the fifth preset rotating speed is smaller than the fourth preset rotating speed, and the fourth preset rotating speed is smaller than the idle rotating speed.

The method comprises the steps of determining a rotating speed difference according to a target rotating speed and the current rotating speed of an engine, determining a generator correction torque according to the rotating speed difference through proportional integral control, searching a generator feedforward torque corresponding to the target rotating speed in a third mapping relation, wherein the third mapping relation is used for representing the relation between the target rotating speed and the generator feedforward torque, and determining a second anti-tugging torque of the generator according to the generator feedforward torque and the generator correction torque.

In one embodiment, a computer readable storage medium is provided having a computer program stored thereon, which when executed by a processor, performs the steps of:

In one embodiment, the computer program when executed by the processor further performs the steps of:

In one embodiment, a computer program product is provided comprising a computer program which, when executed by a processor, performs the steps of:

It should be noted that, the user information (including but not limited to user equipment information, user personal information, etc.) and the data (including but not limited to data for analysis, stored data, presented data, etc.) related to the present application are information and data authorized by the user or sufficiently authorized by each party, and the collection, use and processing of the related data need to comply with the related laws and regulations and standards of the related country and region.

Those skilled in the art will appreciate that implementing all or part of the above described methods may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed, may comprise the steps of the embodiments of the methods described above. Any reference to memory, database, or other medium used in embodiments provided herein may include at least one of non-volatile and volatile memory. The nonvolatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical Memory, high density embedded nonvolatile Memory, resistive random access Memory (ReRAM), magneto-resistive random access Memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric Memory (Ferroelectric Random Access Memory, FRAM), phase change Memory (PHASE CHANGE Memory, PCM), graphene Memory, and the like. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, and the like. By way of illustration, and not limitation, RAM can be in various forms such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), etc. The databases referred to in the embodiments provided herein may include at least one of a relational database and a non-relational database. The non-relational database may include, but is not limited to, a blockchain-based distributed database, and the like. The processor referred to in the embodiments provided in the present application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, or the like, but is not limited thereto.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The foregoing examples illustrate only a few embodiments of the application and are described in detail herein without thereby limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of the application should be assessed as that of the appended claims.

Claims

1. A method for controlling cold start of an engine, the method comprising:

Acquiring the temperature of an engine;

Determining a first reverse towing torque of a generator according to the engine temperature and the speed change rate, and controlling the cold start of the engine based on the first reverse towing torque, the first preset speed, the current speed and the idle speed;

Under the condition that a second preset relation is met between the temperature of the engine and a temperature threshold value, acquiring battery electric quantity and the current rotating speed of the engine, determining the target rotating speed of the engine according to the battery electric quantity, determining the second anti-dragging torque of the generator according to the target rotating speed and the current rotating speed of the engine, and controlling the cold start of the engine based on the second anti-dragging torque, the current rotating speed of the engine, the second preset rotating speed and the target rotating speed.

2. The method of claim 1, wherein the controlling the engine cold start based on the second counter-drag torque, the current engine speed, a second preset speed, and the target speed comprises:

Controlling the generator to output the second anti-dragging torque, controlling the engine to continuously spray oil and ignite until the compression ignition of the engine is successful, controlling the engine to stop spraying oil and igniting, and controlling the generator to stop outputting the torque within a second preset time period;

And determining that the cold start of the engine is finished when the current rotating speed of the engine at any moment in the second preset time is larger than the second preset rotating speed, wherein the second preset rotating speed is larger than the target rotating speed.

3. The method of claim 2, wherein after the controlling the generator to output the second counter-drag torque, further comprising:

4. The method of claim 1, wherein the controlling the engine cold start based on the first counter-drag torque, a first preset rotational speed, a current engine rotational speed, and an idle rotational speed comprises:

controlling the generator to output the first anti-dragging torque until the current rotating speed of the engine reaches a first preset rotating speed, and controlling the generator to stop outputting the torque, wherein the first preset rotating speed is larger than the idle rotating speed;

Determining output torque of the engine according to the idle speed under the condition that the current rotating speed of the engine is reduced to the idle speed, and controlling the engine to output the output torque;

And determining that the cold start of the engine is finished under the condition that the duration of the output of the idle speed of the engine exceeds a second duration threshold.

5. The method of claim 1, wherein said determining a first counter-drag torque of a generator based on said engine temperature and said rate of change of rotational speed comprises:

and determining a first anti-drag torque of the generator according to the engine friction torque and the generator correction torque.

6. The method of claim 1, wherein determining a target speed of the engine based on the battery charge comprises:

under the condition that the battery electric quantity is higher than an electric quantity threshold value, determining that the target rotating speed of the engine is a fourth preset rotating speed;

And determining the target rotating speed of the engine as a fifth preset rotating speed under the condition that the electric quantity of the battery is not higher than the electric quantity threshold value, wherein the fifth preset rotating speed is smaller than the fourth preset rotating speed, and the fourth preset rotating speed is smaller than the idle rotating speed.

7. The method of claim 1, wherein determining a second counter-drag torque of a generator based on the target speed, the current engine speed, comprises:

and determining a second anti-drag torque of the generator according to the generator feedforward torque and the generator correction torque.

8. An engine cold start control apparatus, characterized by comprising:

the acquisition module is used for acquiring the temperature of the engine;

the second control module is used for acquiring battery electric quantity and current engine rotating speed under the condition that a second preset relation is met between the temperature of the engine and a temperature threshold value, determining target engine rotating speed according to the battery electric quantity, determining second anti-dragging torque of the generator according to the target rotating speed and the current engine rotating speed, and controlling cold start of the engine based on the second anti-dragging torque, the current engine rotating speed, the second preset rotating speed and the target rotating speed.

9. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method of any of claims 1 to 7 when the computer program is executed.

10. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1 to 7.

11. A computer program product comprising a computer program, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1 to 7.