阅读说明：本技术 一种车辆减排方法和装置 (Vehicle emission reduction method and device ) 是由 崔亚彬 陈立明 邢化锋 耿路 姜兴洪 于 2020-04-01 设计创作，主要内容包括：本发明实施例提供的一种车辆减排方法和装置,应用于车辆中的发动机控制单元,所述方法包括：在所述发动机中处于停缸状态的目标气缸切换至正常状态时,获取进入发动机排气系统的总气量；根据所述总气量确定目标喷油量；控制所述目标气缸的喷油器按照所述目标喷油量进行喷油,并控制所述目标气缸的火花塞进行点火。在发动机中处于停缸状态的目标气缸切换至正常状态时,通过依据发动机进入排气系统的总气量,控制目标气缸中喷油器根据该总气量喷射对应的目标喷油量,使得喷油器所喷射的燃油与发动机排气系统中的空气,可以按照三效催化器要求的空气和然后的标准比值进行混合,从而保证了三效催化器的尾气处理效率。(The embodiment of the invention provides a vehicle emission reduction method and device, which are applied to an engine control unit in a vehicle, and the method comprises the following steps: when a target cylinder in a cylinder deactivation state in the engine is switched to a normal state, acquiring the total air quantity entering an exhaust system of the engine; determining a target fuel injection quantity according to the total gas quantity; and controlling the fuel injector of the target cylinder to inject fuel according to the target fuel injection quantity, and controlling the spark plug of the target cylinder to ignite. When a target cylinder in a cylinder deactivation state in an engine is switched to a normal state, a fuel injector in the target cylinder is controlled to inject corresponding target fuel injection quantity according to the total gas quantity of the engine entering an exhaust system, so that fuel oil injected by the fuel injector and air in the exhaust system of the engine can be mixed according to the air required by the three-way catalyst and a standard ratio, and the tail gas treatment efficiency of the three-way catalyst is ensured.)

1. An emission reduction method for a vehicle, characterized by being applied to an engine control unit in a vehicle, the method comprising:

when a target cylinder in a cylinder deactivation state in the engine is switched to a normal state, acquiring the total air quantity entering an exhaust system of the engine;

determining a target fuel injection quantity according to the total gas quantity;

and controlling the fuel injector of the target cylinder to inject fuel according to the target fuel injection quantity, and controlling the spark plug of the target cylinder to ignite.

2. The method of claim 1, wherein the step of obtaining the total amount of gas entering an exhaust system of an engine when a target cylinder in a deactivated state in the engine is switched to a normal state further comprises:

when a target cylinder in a cylinder deactivation state in the engine needs to be switched to a normal state, switching the target cylinder to a transition state; the transition state refers to that an intake valve and an exhaust valve of the target cylinder are in an operation state, and a throttle valve, an oil injector and a spark plug are in a stop state;

and when the current air pressure of the intake manifold of the target cylinder reaches the target air pressure of the intake manifold, switching the target cylinder to a normal state, wherein the normal state refers to that an intake valve, an exhaust valve, a throttle valve, an oil injector and a spark plug of the target cylinder are in a running state.

3. The method of claim 2, wherein the step of obtaining a total amount of gas entering an engine exhaust system comprises:

acquiring a first air quantity entering an engine exhaust system when the target cylinder is in a transition state;

acquiring a second air quantity entering an engine exhaust system in the process that the target cylinder enters a cylinder deactivation state;

and combining the first air quantity and the second air quantity to obtain the total air quantity entering an exhaust system of the engine.

4. The method of claim 3, wherein the step of obtaining a first amount of air entering an engine exhaust system while the target cylinder is in the transient state comprises:

inquiring a preset first mapping relation according to the target torque and the rotating speed of the engine to obtain the target intake manifold pressure, wherein the preset first mapping relation is used for describing the mapping relation between the target torque and the rotating speed of the engine and the target intake manifold pressure;

obtaining a pressure difference according to the current intake manifold pressure of a target cylinder and the target intake manifold pressure;

determining a first air inflow according to the pressure difference and the volume of an intake manifold;

and adjusting the first air inflow according to a preset mode to obtain a first air amount entering an engine exhaust system.

5. The method of claim 4, wherein the step of adjusting the first intake air amount in a predetermined manner to obtain the first air amount entering the exhaust system of the engine comprises:

inquiring a preset second mapping relation according to the time interval of the engine in the transition state to obtain a transition state correction coefficient, wherein the preset second mapping relation is used for describing the mapping relation between the time interval of the engine in the transition state and the transition state correction coefficient;

and obtaining a first air quantity entering an engine exhaust system according to the first air inflow and the transition state correction coefficient.

6. The method of claim 5, wherein the step of deriving a first air amount into an engine exhaust system based on the first intake air amount and the transient state correction factor comprises:

obtaining air leakage of the throttle valve according to the time interval of the engine in the transition state and the air leakage of the throttle valve in unit time;

correcting the first air inflow according to the transition state correction coefficient to obtain a corrected first air inflow;

and combining the corrected first air inflow with the air leakage of the throttle valve to obtain a first air amount entering an exhaust system of the engine.

7. The method of claim 3, wherein said step of obtaining a second amount of air entering an engine exhaust system during said target cylinder entering a deactivated state comprises:

determining a second air intake quantity according to the effective displacement of the engine and the current intake manifold pressure of the target cylinder, wherein the effective displacement is determined according to the standard displacement of the engine and the valve timing position of an intake valve in the target cylinder;

and determining a second air quantity entering an exhaust system of the engine according to the operation times of the target cylinder and the second air inflow in the process that the target cylinder enters the cylinder deactivation state.

8. The method of claim 1, wherein the step of determining a target fuel injection amount based on the total amount of fuel comprises:

determining a limit value of the air quantity of an exhaust system of the engine according to the current pressure of an exhaust manifold of the engine and the effective volume of the exhaust system;

when the total gas volume is larger than the gas volume limit value, taking the gas volume limit value as a target gas volume;

when the total gas amount is less than or equal to the gas amount limit value, taking the total gas amount as a target gas amount;

and determining a target fuel injection quantity according to the target gas quantity.

9. The method of claim 8, wherein the step of determining a target fuel injection quantity based on the target gas quantity comprises:

determining a standard oil injection quantity according to the target gas quantity;

inquiring a preset fourth mapping relation according to the temperature of a catalyst of the engine to obtain combustion efficiency, wherein the preset fourth mapping relation is used for describing the mapping relation between the temperature of the catalyst and the combustion efficiency;

and determining a target fuel injection quantity according to the standard fuel injection quantity and the combustion efficiency.

10. An emission abatement device for a vehicle, characterised by an engine control unit for use in a vehicle, the device being arranged to apply the method of any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of vehicles, in particular to a vehicle emission reduction method and device.

Background

As an important transportation means, automobiles have been widely used in various aspects of daily life. However, with the increasingly severe global environmental problems and the lack of energy, the more stringent emission standards and lower fuel consumption of automobiles become the mainstream trend of the social demands for automobile engines.

The cylinder deactivation technology is a widely used engine technology, and when the engine runs at a low load, the fuel supply, ignition, intake and exhaust valves of a part of cylinders are closed to stop the part of cylinders, so that the load of the rest working cylinders is increased, the working efficiency of the engine is improved, and the fuel consumption is reduced.

For an engine adopting a cylinder deactivation technology, after a part of cylinders of the engine are switched from a normal state to a cylinder deactivation state, a throttle valve, an intake valve and an exhaust valve are all in a stop state, and oil injection and ignition are stopped, the part of cylinders do not consume air at the moment, but the air pressure in an intake manifold can gradually approach the atmospheric pressure due to the influence of factors such as air leakage of the throttle valve and the like, so that when the part of cylinders in the cylinder deactivation state enter the normal state again, the air quantity entering an exhaust system of the engine can not reach the standard ratio of the air and the fuel required by the normal work of a three-way catalyst after being mixed with the fuel, and the efficiency of tail gas treatment of the catalyst is reduced.

Disclosure of Invention

In view of the above, the present invention aims to provide a vehicle emission reduction method and device, so as to solve the problem that in the prior art, when a cylinder in a cylinder deactivation state is switched to a normal state, the exhaust gas treatment efficiency of a three-way catalyst is reduced due to excessive air entering an engine exhaust system.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a vehicle emission reduction method applied to an engine control unit in a vehicle, the method comprising:

when a target cylinder in a cylinder deactivation state in the engine is switched to a normal state, acquiring the total air quantity entering an exhaust system of the engine;

determining a target fuel injection quantity according to the total gas quantity;

and controlling the fuel injector of the target cylinder to inject fuel according to the target fuel injection quantity, and controlling the spark plug of the target cylinder to ignite.

Optionally, before the step of obtaining the total amount of air entering an exhaust system of the engine when a target cylinder in a cylinder deactivation state in the engine is switched to a normal state, the method further includes:

when a target cylinder in a cylinder deactivation state in the engine needs to be switched to a normal state, switching the target cylinder to a transition state; the transition state refers to that an intake valve and an exhaust valve of the target cylinder are in an operation state, and a throttle valve, an oil injector and a spark plug are in a stop state;

and when the current air pressure of the intake manifold of the target cylinder reaches the target air pressure of the intake manifold, switching the target cylinder to a normal state, wherein the normal state refers to that an intake valve, an exhaust valve, a throttle valve, an oil injector and a spark plug of the target cylinder are in a running state.

Optionally, the step of obtaining the total amount of air entering the exhaust system of the engine comprises:

acquiring a first air quantity entering an engine exhaust system when the target cylinder is in a transition state;

acquiring a second air quantity entering an engine exhaust system in the process that the target cylinder enters a cylinder deactivation state;

and combining the first air quantity and the second air quantity to obtain the total air quantity entering an exhaust system of the engine.

Optionally, the step of obtaining a first air volume entering an exhaust system of the engine when the target cylinder is in the transition state includes:

inquiring a preset first mapping relation according to the target torque and the rotating speed of the engine to obtain the target intake manifold pressure, wherein the preset first mapping relation is used for describing the mapping relation between the target torque and the rotating speed of the engine and the target intake manifold pressure;

obtaining a pressure difference according to the current intake manifold pressure of a target cylinder and the target intake manifold pressure;

determining a first air inflow according to the pressure difference and the volume of an intake manifold;

and adjusting the first air inflow according to a preset mode to obtain a first air amount entering an engine exhaust system.

Optionally, the step of adjusting the first intake air amount according to a preset manner to obtain a first air amount entering an engine exhaust system includes:

inquiring a preset second mapping relation according to the time interval of the engine in the transition state to obtain a transition state correction coefficient, wherein the preset second mapping relation is used for describing the mapping relation between the time interval of the engine in the transition state and the transition state correction coefficient;

and obtaining a first air quantity entering an engine exhaust system according to the first air inflow and the transition state correction coefficient.

Optionally, the step of obtaining a first air quantity entering an engine exhaust system according to the first intake air quantity and the transient state correction coefficient includes:

obtaining air leakage of the throttle valve according to the time interval of the engine in the transition state and the air leakage of the throttle valve in unit time;

correcting the first air inflow according to the transition state correction coefficient to obtain a corrected first air inflow;

and combining the corrected first air inflow with the air leakage of the throttle valve to obtain a first air amount entering an exhaust system of the engine.

Optionally, the step of obtaining a second air amount entering an exhaust system of the engine during the process that the target cylinder enters the cylinder deactivation state includes:

determining a second air intake quantity according to the effective displacement of the engine and the current intake manifold pressure of the target cylinder, wherein the effective displacement is determined according to the standard displacement of the engine and the valve timing position of an intake valve in the target cylinder;

and determining a second air quantity entering an exhaust system of the engine according to the operation times of the target cylinder and the second air inflow in the process that the target cylinder enters the cylinder deactivation state.

Optionally, the step of determining the target fuel injection quantity according to the total gas quantity includes:

determining a limit value of the air quantity of an exhaust system of the engine according to the current pressure of an exhaust manifold of the engine and the effective volume of the exhaust system;

when the total gas volume is larger than the gas volume limit value, taking the gas volume limit value as a target gas volume;

when the total gas amount is less than or equal to the gas amount limit value, taking the total gas amount as a target gas amount;

and determining a target fuel injection quantity according to the target gas quantity.

Optionally, the step of determining the target fuel injection quantity according to the target gas quantity includes:

determining a standard oil injection quantity according to the target gas quantity;

inquiring a preset fourth mapping relation according to the temperature of a catalyst of the engine to obtain combustion efficiency, wherein the preset fourth mapping relation is used for describing the mapping relation between the temperature of the catalyst and the combustion efficiency;

and determining a target fuel injection quantity according to the standard fuel injection quantity and the combustion efficiency.

Rounding the first oil injection frequency according to a preset carry system to obtain a second oil injection frequency;

and controlling the oil injector of the target cylinder to inject oil according to the second oil injection frequency and the single oil injection quantity.

A vehicle emission reduction device for use in an engine control unit in a vehicle, the device comprising:

the acquisition module is used for acquiring the total air quantity entering an exhaust system of the engine when a target cylinder in a cylinder deactivation state in the engine is switched to a normal state;

the determining module is used for determining a target fuel injection quantity according to the total gas quantity;

and the control module is used for controlling the oil injector of the target cylinder to inject oil according to the target oil injection quantity and controlling the spark plug of the target cylinder to ignite.

Optionally, the apparatus further includes:

the first switching module is used for switching a target cylinder in a cylinder deactivation state in the engine to a transition state when the target cylinder needs to be switched to a normal state; the transition state refers to that an intake valve and an exhaust valve of the target cylinder are in an operation state, and a throttle valve, an oil injector and a spark plug are in a stop state;

and the second switching module is used for switching the target cylinder to a normal state when the current air pressure of the intake manifold of the target cylinder reaches the target air pressure of the intake manifold, wherein the normal state refers to that an intake valve, an exhaust valve, a throttle valve, an oil injector and a spark plug of the target cylinder are in an operating state.

Optionally, the obtaining module includes:

the first acquisition submodule is used for acquiring a first air quantity entering an engine exhaust system when the target cylinder is in a transition state;

the second obtaining submodule is used for obtaining a second air quantity entering an engine exhaust system in the process that the target cylinder enters the cylinder deactivation state;

and the third obtaining submodule is used for combining the first air quantity and the second air quantity to obtain the total air quantity entering the exhaust system of the engine.

Optionally, the first obtaining sub-module includes:

the first determining unit is used for inquiring a preset first mapping relation according to the target torque and the rotating speed of the engine to obtain the target intake manifold pressure, and the preset first mapping relation is used for describing the mapping relation among the target torque, the rotating speed and the target intake manifold pressure of the engine;

the second determining unit is used for obtaining a pressure difference according to the current intake manifold pressure of the target cylinder and the target intake manifold pressure;

a third determination unit for determining a first intake air amount based on the pressure difference and a volume of an intake manifold;

and the adjusting unit is used for adjusting the first air inflow according to a preset mode to obtain a first air amount entering an engine exhaust system.

Optionally, the adjusting unit is further configured to:

inquiring a preset second mapping relation according to the time interval of the engine in the transition state to obtain a transition state correction coefficient, wherein the preset second mapping relation is used for describing the mapping relation between the time interval of the engine in the transition state and the transition state correction coefficient;

and obtaining a first air quantity entering an engine exhaust system according to the first air inflow and the transition state correction coefficient.

Optionally, the adjusting unit is further configured to:

obtaining air leakage of the throttle valve according to the time interval of the engine in the transition state and the air leakage of the throttle valve in unit time;

correcting the first air inflow according to the transition state correction coefficient to obtain a corrected first air inflow;

and combining the corrected first air inflow with the air leakage of the throttle valve to obtain a first air amount entering an exhaust system of the engine.

Optionally, the second obtaining sub-module includes:

a fourth determination unit, configured to determine a second intake air amount according to an effective displacement of the engine and a current intake manifold pressure of the target cylinder, wherein the effective displacement is determined according to a standard displacement of the engine and a valve timing position of an intake valve in the target cylinder;

and the fifth determining unit is used for determining a second air quantity entering the exhaust system of the engine according to the running times of the target cylinder and the second air inflow in the process that the target cylinder enters the cylinder deactivation state.

Optionally, the determining module includes:

the first determining submodule is used for determining a limit value of a gas quantity of an exhaust system of the engine according to the current exhaust manifold pressure of the engine and the effective volume of the exhaust system;

the first processing submodule is used for taking the gas limit value as a target gas quantity when the total gas quantity is greater than the gas limit value;

the second processing submodule is used for taking the total gas amount as a target gas amount when the total gas amount is less than or equal to the gas amount limit value;

and the second determining submodule is used for determining the target fuel injection quantity according to the target gas quantity.

Optionally, the second determining sub-module includes:

the sixth determining unit is used for determining a standard oil injection quantity according to the target gas quantity;

the seventh determining unit is used for inquiring a preset fourth mapping relation according to the temperature of the catalyst of the engine to obtain the combustion efficiency, and the preset fourth mapping relation is used for describing the mapping relation between the temperature of the catalyst and the combustion efficiency;

and the eighth determining unit is used for determining the target fuel injection quantity according to the standard fuel injection quantity and the combustion efficiency.

Optionally, the control module includes:

the third determining submodule is used for determining the first oil injection frequency according to the ratio of the target oil injection quantity to the single oil injection quantity of the oil injector;

the third processing submodule is used for rounding the first oil injection frequency according to a preset carry system to obtain a second oil injection frequency;

and the control submodule is used for controlling the oil injector of the target cylinder to inject oil according to the second oil injection frequency and the single oil injection quantity.

Compared with the prior art, the vehicle emission reduction method and the vehicle emission reduction device have the following advantages:

the vehicle emission reduction method and the device provided by the embodiment of the invention are applied to an engine control unit in a vehicle, when a target cylinder in a cylinder deactivation state in the engine is switched to a normal state, a fuel injector in the target cylinder is controlled to inject corresponding target fuel injection quantity according to the total gas quantity of the engine entering an exhaust system, so that fuel oil injected by the fuel injector and air in the exhaust system of the engine can be mixed according to the standard ratio of the air and the fuel oil required by a three-way catalyst, and the tail gas treatment efficiency of the three-way catalyst is ensured.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a flow chart illustrating steps of a method for reducing emissions from a vehicle, in accordance with an embodiment of the present invention;

FIG. 2 is a block diagram of an engine according to an embodiment of the present invention;

FIG. 3 is a flow chart illustrating steps of another method for reducing emissions from a vehicle, in accordance with an embodiment of the present invention;

FIG. 4 is a flowchart illustrating steps of a first method for determining an amount of gas according to an embodiment of the present invention;

FIG. 5 is a flowchart illustrating steps of a first method for correcting an amount of gas according to an embodiment of the present invention;

FIG. 6 is a flowchart illustrating steps of a second method for correcting a first air quantity according to an embodiment of the present invention;

fig. 7 is a flowchart illustrating steps of a second gas amount determining method according to an embodiment of the present invention;

FIG. 8 is a logic diagram of calculating a total gas amount according to the embodiment of the present invention;

FIG. 9 is a flowchart illustrating steps of a method for determining a target fuel injection amount according to an embodiment of the present invention;

FIG. 10 is a logic diagram illustrating a calculation of a target fuel injection amount according to an embodiment of the present invention;

fig. 11 is a block diagram of a vehicle emission reduction device according to an embodiment of the present invention.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In this embodiment, the operating state of the engine is divided into a full-cylinder operating state and a random cylinder deactivation operating state. The all-cylinder working state is a state that all cylinders of the engine work; the random cylinder deactivation working state refers to that in the running process of the vehicle, the engine is controlled to work at different cylinder deactivation rates and cylinder deactivation sequences according to torque requirements under different loads, namely the vehicle can randomly control part of cylinders to stop working according to different torque requirements, so that the purpose that the engine can work with the fewest cylinders on the premise of meeting the torque requirements is achieved, and the optimal working condition oil consumption of the engine can be achieved as far as possible. The scheme of the invention aims to solve the problem that when the cylinder in the partial cylinder deactivation state in the engine in the random cylinder deactivation state enters the normal state again, the mixed ratio of air and fuel oil cannot reach the standard ratio required by the three-way catalyst due to excessive air entering the exhaust system of the engine, and the tail gas treatment efficiency of the three-way catalyst is influenced.

The random cylinder deactivation working state can save the energy consumption of the engine, and the principle thereof is as follows:

the engine pushes the piston to rotate by consuming fuel oil in the working process, but the consumed fuel oil generates energy which is used for pushing the piston to rotate the crankshaft, and besides, part of the energy is taken away by high-temperature tail gas and cooling water, and part of the energy is used for overcoming friction resistance to do work, and in addition, part of the energy is used for overcoming pumping loss. Further, the larger the engine displacement, the greater the capacity loss due to friction and pumping loss, and therefore, the same torque is output and the smaller the energy loss of the small displacement engine to overcome friction and pumping loss is than that of the large displacement engine. Therefore, if the engine is controlled to operate at a low load, that is, when the target torque is small, the torque output by the cylinders which are partially closed and are ensured to continue operating can meet the target torque demand of the engine, and since the partial cylinders are closed, which corresponds to the reduction of the displacement of the engine, the pumping loss and the friction loss can be reduced.

It can be seen that the working principle of the random cylinder deactivation working state is equivalent to dynamically adjusting the displacement of the engine according to different working conditions, thereby realizing the reduction of the energy consumption of the engine. In order to achieve the random cylinder deactivation operating state, each cylinder of the engine should have an intake valve and an exhaust valve that can be closed or opened individually at any time.

In order to realize the random cylinder deactivation working state, each cylinder of the engine is provided with an intake valve, an exhaust valve, an oil nozzle and an ignition device which can be independently opened and closed, so that the intake and the exhaust of any cylinder can be stopped by closing the intake valve and the exhaust valve at any time, and the ignition and the oil injection are simultaneously stopped, thereby realizing the random cylinder deactivation effect.

Specifically, the control process of the random cylinder deactivation of the embodiment may include: acquiring a target torque of an engine; determining whether a random cylinder deactivation working state needs to be entered; if the random cylinder deactivation working state needs to be entered, determining the running state of the vehicle; when the running state of the vehicle is a steady state, determining a target cylinder deactivation rate corresponding to the target torque according to the target torque; when the running state of the vehicle is transient, determining a target cylinder deactivation rate corresponding to the target torque according to the target torque and the acceleration and deceleration state of the vehicle; the acceleration and deceleration state comprises an acceleration state and a deceleration state, and the target cylinder deactivation rate corresponding to the acceleration state is greater than the target cylinder deactivation rate corresponding to the deceleration state; and controlling the engine to work according to the target cylinder deactivation rate.

The method comprises the following steps that different cylinder deactivation rates correspond to different outer characteristic curve graphs, the outer characteristic curve graphs are determined by torque and engine rotating speed, and a preset optimal oil consumption area is arranged in the outer characteristic curve graphs and is obtained in advance according to actual use. Because the outer characteristic curve chart is determined by the torque and the engine rotating speed, and the preset optimal oil consumption area is arranged in the outer characteristic curve chart, after the condition that the engine needs to enter the random cylinder deactivation working state is determined, the corresponding target cylinder deactivation rate is determined according to the target torque and the current rotating speed, so that the target torque is in the optimal oil consumption area of the outer characteristic curve chart, the target torque can be input into the engine, and the engine can work in the optimal oil consumption state on the premise of outputting the target torque, so that the oil consumption is saved.

In addition, a cylinder deactivation table corresponding to the target cylinder deactivation rate can be obtained according to the preset corresponding relation between the cylinder deactivation rate and the cylinder deactivation table; the cylinder deactivation table is preset with the number of cylinders deactivated in a plurality of working cycles and the cylinder sequence of cylinder deactivation. And controlling the engine to work according to the number of cylinders deactivated in a plurality of working cycles in the cylinder deactivation table and the cylinder sequence of cylinder deactivation. On the basis of meeting the target cylinder deactivation rate, the engine can be controlled to perform cylinder deactivation according to a cylinder deactivation table. The cylinder deactivation table may take into account noise, vibration, and harshness factors to minimize vibration when the engine is operating at the same cylinder deactivation rate. When the cylinder deactivation rate of the engine changes, part of the cylinders in the cylinder deactivation state in the engine needs to be switched to a normal state, and at the moment, if the amount of air exhausted into an exhaust system of the engine by the part of the cylinders is too much, the exhaust gas treatment efficiency of the three-way catalyst is affected.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

Referring to fig. 1, an embodiment of the present invention provides a vehicle emission reduction method applied to an engine control unit in a vehicle, and the method may include:

step 101, when a target cylinder in a cylinder deactivation state in the engine is switched to a normal state, acquiring the total air quantity entering an exhaust system of the engine.

In the embodiment of the invention, when the three-way catalyst works, the mass ratio of air to fuel oil in an exhaust system of an engine needs to be ensured to reach a certain standard ratio, and if the mass ratio of air to fuel oil in the exhaust system of the engine is higher than the standard ratio due to overlarge air amount, the exhaust emission of the engine is increased, and the exhaust treatment efficiency of the three-way catalyst is reduced.

During the running process of the vehicle, the engine is switched to a random cylinder deactivation state according to a target torque required to be output, the cylinder deactivation rate required to be switched for starting is determined according to the target torque, and partial cylinders in the engine are switched to the cylinder deactivation state from a normal state according to the cylinder deactivation rate, so that the energy consumption is reduced. However, if the target torque required to be output by the engine increases, the cylinder deactivation rate decreases accordingly, and it is necessary to switch the target cylinder among the partial cylinders in the cylinder deactivation state to the normal state, so as to increase the output torque of the engine. At the moment, air sucked by the target cylinder when the target cylinder is switched from the normal state to the cylinder deactivation state is not used, and the air leakage of the throttle valve is caused to a certain extent, so that the air quantity entering an engine exhaust system when the target cylinder is switched from the cylinder deactivation state to the normal state is too large, fuel oil sprayed by an oil sprayer of the target cylinder is mixed with too much air, and the mass of the air and the fuel oil cannot meet the standard ratio required by the normal operation of the three-way catalyst. Normally, the standard ratio of the air and the fuel mixture entering the exhaust system of the engine required by the three-way catalyst needs to reach 14.7, and the standard ratio can be determined according to the actual condition of the three-way catalyst in the engine, and the standard ratio is only used for illustration, and the embodiment of the invention is not limited in particular.

Therefore, when the target cylinder needs to be switched from the cylinder deactivation state to the normal state, the fuel injection quantity of the target cylinder is adjusted according to the total air quantity entering the engine exhaust system when the target cylinder is switched from the cylinder deactivation state to the normal state instead of performing fuel injection according to the original fuel injection quantity of the target cylinder, so that the mass ratio of air to fuel in the engine exhaust system when the target cylinder is switched from the cylinder deactivation state to the normal state is adjusted.

The cylinder deactivation state refers to the state that an intake valve, an exhaust valve, a throttle valve, a spark plug and an oil injector of a target cylinder are stopped, and the normal state refers to the state that the intake valve, the exhaust valve, the spark plug and the oil injector of the target cylinder are in operation.

Referring to fig. 2, in an engine structure diagram, Cyl1 to Cyl4 are fuel injectors of the engine, the number 1 is the engine, the number 2 is an exhaust valve, the number 4 is a TWC (Three Way catalyst Converter), an exhaust system of the engine is a closed region (number 3) between the TWC (number 4) and the exhaust valve (number 2), and the closed region includes an exhaust manifold and a space in front of a part of the Three-Way catalyst.

And step 102, determining a target fuel injection quantity according to the total gas quantity.

In the embodiment of the invention, the total gas quantity is divided by the standard ratio of the air and the fuel oil required by the normal operation of the three-effect catalyst, so that the target fuel injection quantity required by the fuel injector of the target cylinder can be obtained.

And 103, controlling the oil injector of the target cylinder to inject oil according to the target oil injection quantity, and controlling the spark plug of the target cylinder to ignite.

In the embodiment of the invention, when the target cylinder is just switched to a normal state from a cylinder deactivation state, the fuel injector of the target cylinder is controlled to inject the fuel oil with the target fuel injection quantity, so that the mass ratio of the air entering an exhaust system of an engine to the fuel oil reaches the standard ratio required by the normal operation of the three-way catalyst, after the fuel injector of the target cylinder injects the fuel oil with the target fuel injection quantity, because the air quantity entering the exhaust system of the engine is recovered to the normal air suction quantity of the air inlet valve, the fuel injector of the target cylinder determines the required oil injection quantity according to the normal air suction quantity of the air inlet valve at the moment, and oil injection is not required according to the target fuel injection quantity.

The embodiment of the invention provides a vehicle emission reduction method, which is characterized in that when a target cylinder in a cylinder deactivation state in an engine is switched to a normal state, a fuel injector in the target cylinder is controlled to inject corresponding target fuel injection quantity according to the total gas quantity of the engine entering an exhaust system according to the total gas quantity, so that fuel oil injected by the fuel injector and air in the exhaust system of the engine can be mixed according to a standard ratio of air and fuel oil required by a three-way catalyst, and the tail gas treatment efficiency of the three-way catalyst is ensured.

Referring to fig. 3, an embodiment of the present invention provides another vehicle emission reduction method applied to an engine control unit in a vehicle, where the method may include:

step 201, when a target cylinder in a cylinder deactivation state in the engine needs to be switched to a normal state, switching the target cylinder to a transition state; wherein the transitional state refers to that an intake valve and an exhaust valve of the target cylinder are in an operating state, and a throttle valve, an injector and an ignition plug are in a stopping state.

In practical applications, the vehicle may have a plurality of different driving states, such as a normal driving state, an acceleration state, a coasting state and a braking state. The coasting state refers to a driving state of the vehicle when the driver does not step on the accelerator pedal or the accelerator pedal is opened to the maximum (of course, the accelerator pedal opening corresponding to different vehicles in the coasting state may be determined according to actual conditions), and the brake pedal is not operated; the acceleration state refers to a state in which the driver steps on the accelerator pedal more largely to enable the vehicle to run with acceleration; the braking state refers to a state in which the driver steps on a brake pedal to enable the vehicle to stop running; the normal running state is a state in which the driver steps on the accelerator pedal or the accelerator pedal opening is not at the maximum, but the target torque of the engine is not changed.

When the vehicle is in a sliding state or a normal running state, determining a target cylinder deactivation rate corresponding to the target torque according to the target torque, controlling the engine to work at different cylinder deactivation rates and cylinder deactivation sequences according to the target cylinder deactivation rate, and when the vehicle needs to run in an accelerated manner, randomly controlling part of cylinders to stop working by searching the corresponding target cylinder deactivation rate according to the target torque so as to realize the working with the least cylinders on the premise of meeting the torque requirement, so that the engine can realize the optimal working condition oil consumption as much as possible; however, when the vehicle is switched from the coasting state or the normal driving state to the acceleration state, the cylinder in the cylinder deactivation state before exists due to the change of the cylinder deactivation rate to be recovered, and the cylinder in the cylinder deactivation state before is stopped for a period of time, the throttle valve corresponding to the cylinder is closed, the intake and exhaust valves are closed, and the engine stops injecting and igniting. At the moment, a certain air leakage amount exists in the throttle valve, air leaks into the air inlet manifold from the front of the throttle valve, and the pressure in the air inlet manifold of the engine is gradually increased from a state of being lower than the atmospheric pressure before sliding to be close to the atmospheric pressure.

During acceleration, the pressure of the intake manifold of the target cylinder is higher than the required pressure, so the pressure of the intake manifold is adjusted to the required pressure, otherwise, the direct intake can cause the whole vehicle to crash.

Based on the above, the invention provides that before the target cylinder is recovered to the normal state from the cylinder deactivation state, the target cylinder is controlled to enter the transitional state of opening the intake valve and the exhaust valve for idle rotation, and the redundant air quantity in the intake manifold is exhausted, so that the pressure of the intake manifold is adjusted to the required pressure.

Step 202, when the current air pressure of the intake manifold of the target cylinder reaches the air pressure of the target intake manifold, switching the target cylinder to a normal state, wherein the normal state refers to that an intake valve, an exhaust valve, a throttle valve, an oil injector and a spark plug of the target cylinder are in an operating state.

In the embodiment of the invention, because the piston in the target cylinder which is in the cylinder deactivation state in the vehicle coasting state or normal driving state is driven by other cylinders in the engine in the normal state to operate, if the intake valve and the exhaust valve of the target cylinder are switched from the stop state to the operation state, the target cylinder idles, the air quantity in the target cylinder is gradually reduced until the current intake manifold pressure of the target cylinder reaches the target intake manifold pressure required by the engine to output the target torque, and the target cylinder can be switched to the normal state.

And 203, acquiring a first air quantity entering an engine exhaust system when the target cylinder is in a transition state.

In the embodiment of the invention, since the throttle valve of the target cylinder is not opened, when the target cylinder enters the normal state, the throttle valve is opened, so that the first air quantity of air discharged by the target cylinder in the transition state will enter the exhaust system of the engine.

Optionally, referring to fig. 4, the step 203 includes:

step 2031, a preset first mapping relation is queried according to the target torque and the rotational speed of the engine to obtain a target intake manifold pressure, wherein the preset first mapping relation is used for describing the mapping relation between the target torque, the rotational speed and the target intake manifold pressure of the engine.

In the embodiment of the invention, the target torque of the engine is determined according to the degree of depression of the accelerator. The preset first mapping relationship may be a first mapping relationship between a target torque and a rotation speed of the engine and a target intake manifold pressure by detecting the target intake manifold pressure required by the engine under the conditions of different target torques and engine rotation speeds through experiments according to different vehicles and engines. The engine control unit can quickly acquire target intake manifold pressures required by different target torques of the engine and the rotating speed of the engine by inquiring the first mapping relation.

Step 2032, a pressure differential is obtained based on the current intake manifold pressure of the target cylinder and the target intake manifold pressure.

In the embodiment of the invention, since the target cylinder needs to adjust the current intake manifold pressure to the target intake manifold pressure in the transition state, the air quantity entering the target cylinder into the exhaust system of the engine in the transition state can be determined according to the pressure difference between the current intake manifold pressure and the target intake manifold pressure.

Step 2033, a first intake air amount is determined based on the pressure differential and the intake manifold volume.

In the embodiment of the invention, the target cylinder enters the air quantity of the exhaust system of the engine in the transition state under the ideal state by using the pressure difference and the volume of the intake manifold through the ideal gas state equation.

P V R T, M V/R T (1)

M is the molar mass of the gas, P is the pressure, V is the manifold volume, R is a constant, and T is the Kelvin temperature. Specifically, in step 2033, M is the first intake air amount, P is the pressure difference, and V is the volume of the intake manifold of the target cylinder, and the following step refers again to the above formula (1), and the following operation will be indicated depending on the amount represented by M, P, V for different operation targets.

Step 2034, adjusting the first intake air amount according to a preset mode to obtain a first air amount entering an engine exhaust system.

In the embodiment of the invention, the error exists between the first air inflow entering the engine exhaust system when the target cylinder is in the transition state and the first air inflow actually entering the engine exhaust system, so that the first air inflow needs to be corrected according to a preset mode, and the obtained first air inflow is more in line with the actual situation.

Optionally, referring to fig. 5, the step 2034 includes:

step 20341, a preset second mapping relation is queried according to the time interval of the engine in the transition state to obtain a transition state correction coefficient, where the preset second mapping relation is used to describe a mapping relation between the time interval of the engine in the transition state and the transition state correction coefficient.

In the embodiment of the invention, since the amount of air in the intake manifold is gradually reduced when the target cylinder is in the transient state, there is an error between the first amount of air actually entering the exhaust system and the first intake air amount, and there is a correlation between the time interval during which the engine is in the transient state and the error. Therefore, the second mapping relationship between the target cylinder at different time intervals in the transient state and the transient state correction coefficient can be experimentally measured. The engine control unit can inquire a corresponding transient state correction coefficient according to the time interval that the target cylinder is in the transient state, and correct the first air inflow to obtain the first air amount. The transient state correction coefficient is used to indicate a correlation between a first intake air amount entering the exhaust system and a first air amount.

And 20342, obtaining a first air quantity entering an engine exhaust system according to the first air inflow and the transient state correction coefficient.

In an embodiment of the present invention, the first amount of air actually taken into the engine exhaust system is equal to the first amount of intake air multiplied by the transient state correction factor.

Optionally, referring to fig. 6, the step 20342 includes:

step 203421, obtaining the air leakage of the throttle valve according to the time interval when the engine is in the transition state and the air leakage of the throttle valve in unit time.

In the embodiment of the invention, because the throttle valve of the target cylinder still has certain air leakage phenomenon when the engine is in the transition state, the air leakage of different throttle valves in unit time can be measured in an experiment according to different engines, and then the air leakage of the throttle valve in the transition state is obtained according to the time interval of the air leakage of the unit time multiplied by the time interval of the engine in the transition state.

Step 203422, the first intake air amount is corrected according to the transient state correction factor, so as to obtain a corrected first intake air amount.

In the embodiment of the invention, the specifically corrected first intake air amount is equal to the product of the obtained transient state correction coefficient and the first intake air amount.

Step 203423, combining the corrected first intake air amount with the throttle leakage to obtain a first air amount entering an engine exhaust system.

In the embodiment of the invention, since the target cylinder needs to adjust the pressure of the intake manifold to the target intake manifold pressure in the transition state, the air leakage of the throttle valve is also introduced into the exhaust system of the engine, and the first air quantity of the target cylinder entering the exhaust system of the engine in the transition state can be obtained by adding the air leakage of the throttle valve and the first air inlet quantity.

And 204, acquiring a second air quantity entering an exhaust system of the engine in the process that the target cylinder enters the cylinder deactivation state.

In the embodiment of the invention, during the process of switching the target cylinder from the normal state to the cylinder deactivation state, as the intake valve and the exhaust valve are gradually closed, a part of air quantity can be sucked into an engine exhaust system along with the rotation of the piston.

Optionally, referring to fig. 7, the step 204 includes:

step 2041, determining a second air intake quantity according to the effective displacement of the engine and the current intake manifold pressure of the target cylinder, wherein the effective displacement is determined according to the standard displacement of the engine and the valve timing position of an intake valve in the target cylinder.

In the embodiment of the invention, after the engine control unit queries the displacement correction coefficient table according to the valve timing position of the intake valve and acquires the corresponding displacement correction coefficient, the displacement correction coefficient is multiplied by the standard displacement of the engine to obtain the effective displacement of the engine at the current valve timing position of the intake valve. The displacement correction coefficient is used for describing a correlation between the standard displacement and the effective displacement of the target cylinder, and the amount of air exhausted and inhaled in each operation period of the target cylinder is changed along with the variation of the displacement correction coefficient under different valve timing positions of the intake valve, so that experiments can be carried out according to the valve timing positions of the different intake valves, the standard displacement and the actual displacement of the engine are counted, and the displacement correction coefficient is obtained so as to establish a third mapping relation between the displacement correction coefficient and the valve timing position of the intake valve. The displacement correction coefficient representation is obtained by integrating a third mapping relationship between the displacement correction coefficient and the valve timing position of the intake valve for subsequent inquiry.

And 2042, determining a second air quantity entering an engine exhaust system according to the running times of the target cylinder and the second air inflow in the process that the target cylinder enters the cylinder deactivation state.

In the embodiment of the invention, the single displacement of the target cylinder in one cycle of operation at the current valve timing position of the intake valve can be obtained by substituting the effective displacement and the current intake manifold pressure into the ideal gas state equation (1). In step 2042, V is the volume of the intake manifold, P is the current intake manifold pressure, and M is the second air quantity.

In the embodiment of the invention, the operation times of the target cylinder can be represented by the operation times of the piston of the target cylinder, the piston can also run up and down twice when the target cylinder runs for one period, and at the moment, the intake valve and the exhaust valve are respectively opened once, so that the operation times of the target cylinder can be determined by the operation times of the piston, and the operation times of the target cylinder can also be determined by the operation period of the crankshaft; of course, the actual opening and closing times of the intake and exhaust valves in each cylinder operation cycle can also be determined according to the valve timing positions of the intake and exhaust valves, so that the operation times of the target cylinder can be represented according to the opening and closing times of the intake and exhaust valves. Of course, the specific representation manner of the operation times of the target cylinder may be determined according to actual requirements, and is not particularly limited herein.

During the switching of the target cylinder from the normal state to the deactivated state, the engine control unit records the operation times of the target cylinder. And multiplying the operation times by the effective displacement to obtain a second air quantity entering an exhaust system of the engine in the process of the target cylinder from the normal state to the cylinder deactivation state.

And step 205, combining the first air quantity and the second air quantity to obtain the total air quantity entering an exhaust system of the engine.

In the embodiment of the invention, the first air quantity of the target cylinder entering the exhaust system of the engine in the transition state and the second air quantity of the target cylinder entering the exhaust system of the engine from the normal state are added, so that the total air quantity of the target cylinder entering the exhaust system of the engine from the cylinder deactivation state to the normal state can be obtained.

In practical application, referring to a logic diagram for calculating total air quantity shown in fig. 8, firstly, a first mapping relation is inquired according to target torque and rotating speed of an engine to obtain target intake manifold pressure, pressure difference is obtained by subtracting the target intake manifold pressure from the current intake manifold pressure, then a second mapping relation is inquired through a time interval when a target cylinder runs in a transition state, then air quantity entering an exhaust system of the target cylinder in the transition state is preliminarily obtained according to the pressure difference, the volume of the intake manifold and a transition state correction coefficient, and then the air quantity is added with a throttle air leakage quantity to obtain the first air quantity entering exhaust of the target cylinder in the transition state; acquiring a Valve Timing position of an intake Valve by inquiring VVT (Variable Valve Timing), acquiring an effective displacement correction coefficient by inquiring a third mapping relation according to the Valve Timing position, then multiplying the effective displacement by the standard displacement of the engine to obtain effective displacement, then acquiring a single air extraction amount of the engine according to the effective displacement and the current pressure of an intake manifold, and multiplying the single air extraction amount by the operation times of a target cylinder in the process that the target cylinder enters a cylinder deactivation state from a normal state to obtain a second air amount entering an exhaust system of the engine in the process that the target cylinder enters the cylinder deactivation state; and finally, adding the first air quantity and the second air quantity to obtain the total air quantity entering the exhaust system.

And step 206, determining a limit value of the air quantity of the exhaust system of the engine according to the current exhaust manifold pressure of the engine and the effective volume of the exhaust system.

In an embodiment of the present invention, the current exhaust manifold pressure of the engine may be measured by a pressure sensor disposed in the exhaust manifold. Since the engine exhaust system in the embodiment of the invention comprises the exhaust manifold and the partial area in front of the three-way catalyst, and air enters the engine exhaust system from the exhaust manifold, the current exhaust manifold pressure measured by the pressure sensor in the exhaust manifold may be greater than the pressure in the space in front of the partial three-way catalyst in the engine exhaust system, and if the air distribution is uniform, the current exhaust manifold pressure is not lower than the pressure in the space in front of the three-way catalyst in the engine exhaust system, so that the limit of the air amount entering the engine exhaust system can be obtained by limiting the air amount in the engine exhaust system through the current exhaust manifold pressure and the effective volume of the exhaust system by the ideal gas state equation (1).

And step 207, taking the gas amount limit value as a target gas amount when the total gas amount is larger than the gas amount limit value.

In an embodiment of the present invention, the air flow limit is based on the current exhaust manifold pressure and the effective volume of the engine exhaust system. And if the total gas quantity is larger than the gas quantity limit value, determining that the total gas quantity entering the exhaust system of the engine has an error, and adopting the gas quantity limit value as a target gas quantity.

And 208, when the total gas amount is less than or equal to the gas amount limit value, taking the total gas amount as a target gas amount.

In the embodiment of the present invention, if the total gas amount is less than or equal to the gas amount limit, it is determined that the total gas amount can be adopted, and the total gas amount is determined as the target gas amount. The total gas quantity which is calculated before and enters the exhaust system of the engine is verified according to the gas quantity limit value which is calculated according to the pressure of the current exhaust manifold, so that the condition that the target air inflow is not in accordance with the reality due to the measurement error is avoided.

And 209, determining a target fuel injection quantity according to the target gas quantity.

In the embodiment of the invention, the target fuel injection quantity can be obtained by dividing the target gas quantity by the standard ratio of air to fuel required by the three-way catalyst.

Optionally, referring to fig. 9, the step 209 includes;

and 2091, determining a standard oil injection quantity according to the target gas quantity.

In the embodiment of the invention, the standard fuel injection quantity is directly obtained by dividing the target gas quantity by the standard ratio of the air and the fuel of the three-way catalyst during normal operation.

Step 2092, a preset fourth mapping relation is inquired according to the temperature of the catalyst of the engine to obtain the combustion efficiency, and the preset fourth mapping relation is used for describing the mapping relation between the temperature of the catalyst and the combustion efficiency.

In the embodiment of the invention, after the fuel injector injects fuel, the fuel gas mixture in the exhaust system of the engine is ignited along with the fuel gas mixture due to the higher temperature, so that the combustion efficiency of the injected standard fuel injection quantity at different catalyst temperatures is measured according to experiments to establish the fourth mapping relation.

Step 2093, determining a target fuel injection quantity according to the standard fuel injection quantity and the combustion efficiency.

In the embodiment of the invention, the target fuel injection quantity is obtained by dividing the standard fuel injection quantity by the combustion efficiency. The fuel quantity injected by the fuel injector is ensured to enable the fuel-air mass mixing ratio in the exhaust system of the engine to meet the standard ratio of the three-way catalyst.

And step 210, determining a first oil injection frequency according to the ratio of the target oil injection quantity to the single oil injection quantity of the oil injector.

In the embodiment of the invention, in the process of injecting oil by the oil injector for multiple times, air in an exhaust system of the engine is mixed with fuel oil, and a spark plug of a target cylinder is matched for multiple times of ignition, so that the temperature of the exhaust system of the engine is increased, and a fuel gas mixture which meets the standard mixing ratio of the three-way catalyst is combusted, thereby ensuring the combustion efficiency of the three-way catalyst.

And step 211, rounding the first oil injection frequency according to a preset carry system to obtain a second oil injection frequency.

In the embodiment of the invention, since the single injection quantity of the injector of the cylinder in different engines is a limit value, the fuel of the target injection quantity needs to be injected in multiple times. The first injection number of injections to be injected is obtained by dividing the target injection amount by the single injection amount. If the first oil injection frequency has a decimal number, the number of the first oil injection frequency can be directly increased to one unit, so that the second oil injection frequency is obtained, and the oil injection quantity injected by the oil injector can be ensured to effectively mix redundant air. In practical applications, the specific default carry system may be determined according to the characteristics of the engine and the actual needs, and is not specifically limited herein.

And 212, controlling an oil injector of the target cylinder to inject oil according to the second oil injection frequency and the single oil injection quantity, and controlling a spark plug of the target cylinder to ignite.

In practical application, referring to fig. 10, a logic diagram of calculating a target fuel injection quantity provided by the invention is shown, and a total quantity of gas entering an exhaust system is obtained by adding a first quantity of gas entering the exhaust system of an engine in a transition state of a target cylinder and a second quantity of gas entering the exhaust system in a process of entering a cylinder deactivation state from a normal state; then obtaining the maximum air quantity from an exhaust valve to a TWC (Three Way catalyst) according to the current exhaust manifold pressure and the effective volume of an exhaust system; determining a target gas amount entering the exhaust system by comparing a gas amount limit from the exhaust valve to the TWC with a total gas amount entering the exhaust system; dividing the target gas quantity by a gas standard ratio of the three-way catalyst to 14.7 to obtain a standard fuel injection quantity; inquiring a combustion efficiency curve (a third mapping relation) according to the TWC temperature to obtain combustion efficiency, and multiplying the combustion efficiency by the standard fuel injection quantity to obtain a target fuel injection quantity; and dividing the target fuel injection quantity by the single fuel injection quantity of the fuel injector to obtain the fuel injection times, and inputting the fuel injection times into a fuel injection distribution management module to control the fuel injector to operate.

The embodiment of the invention provides another vehicle emission reduction method, which comprises the steps of determining a target fuel injection quantity according to a first gas quantity entering an engine exhaust system of a target cylinder in a cylinder deactivation state and a second gas quantity entering the engine exhaust system of the target cylinder in a transition state, enabling a fuel injector of the target cylinder to inject fuel according to the target fuel injection quantity, and mixing the injected fuel with air in the engine exhaust system according to a standard ratio of the air and the fuel required by a three-way catalyst, so that the tail gas treatment efficiency of the three-way catalyst is ensured.

Referring to fig. 11, there is shown a block diagram 30 of a vehicle emission reduction device, applied to an engine control unit in a vehicle, the device comprising:

the obtaining module 301 is configured to obtain a total amount of air entering an exhaust system of an engine when a target cylinder in a cylinder deactivation state in the engine is switched to a normal state.

And the determining module 302 is configured to determine a target fuel injection amount according to the total gas amount.

And the control module 303 is configured to control the fuel injector of the target cylinder to inject fuel according to the target fuel injection amount, and control the spark plug of the target cylinder to ignite.

Optionally, the apparatus further includes:

the first switching module 304 is used for switching a target cylinder in a cylinder deactivation state in the engine to a transition state when the target cylinder needs to be switched to a normal state. Wherein the transitional state refers to that an intake valve and an exhaust valve of the target cylinder are in an operating state, and a throttle valve, an injector and an ignition plug are in a stopping state.

The second switching module 305 is configured to switch the target cylinder to a normal state when the current intake manifold air pressure of the target cylinder reaches a target intake manifold air pressure, where the normal state refers to an operation state of an intake valve, an exhaust valve, a throttle valve, an injector, and a spark plug of the target cylinder.

Optionally, the obtaining module 301 includes:

the first obtaining submodule 3011 is configured to obtain a first air amount entering an exhaust system of the engine when the target cylinder is in a transition state.

And the second obtaining submodule 3012 is configured to obtain a second air amount entering an exhaust system of the engine when the target cylinder enters the cylinder deactivation state.

And the third obtaining submodule 3013 is configured to combine the first air quantity and the second air quantity to obtain a total air quantity entering an exhaust system of the engine.

Optionally, the first obtaining sub-module 3011 includes:

the first determining unit 30111 is configured to query a preset first mapping relationship according to a target torque of the engine and a rotation speed of the engine to obtain a target intake manifold pressure, where the preset first mapping relationship is used to describe a mapping relationship between the target torque of the engine, the rotation speed of the engine, and the target intake manifold pressure.

A second determination unit 30112, configured to obtain a pressure difference according to the current intake manifold pressure of the target cylinder and the target intake manifold pressure.

A third determination unit 30113, configured to determine the first intake air amount based on the pressure difference and the volume of the intake manifold.

And the adjusting unit 30114 is configured to adjust the first intake air amount according to a preset manner, so as to obtain a first air amount entering an engine exhaust system.

Optionally, the adjusting unit 30114 is further configured to:

inquiring a preset second mapping relation according to the time interval of the engine in the transition state to obtain a transition state correction coefficient, wherein the preset second mapping relation is used for describing the mapping relation between the time interval of the engine in the transition state and the transition state correction coefficient;

and obtaining a first air quantity entering an engine exhaust system according to the first air inflow and the transition state correction coefficient.

Optionally, the adjusting unit 30114 is further configured to:

obtaining air leakage of the throttle valve according to the time interval of the engine in the transition state and the air leakage of the throttle valve in unit time;

correcting the first air inflow according to the transition state correction coefficient to obtain a corrected first air inflow;

and combining the corrected first air inflow with the air leakage of the throttle valve to obtain a first air amount entering an exhaust system of the engine.

Optionally, the second obtaining sub-module 3012 includes:

a fourth determining unit 30121, configured to determine the second intake air amount according to an effective displacement of the engine and a current intake manifold pressure of the target cylinder, where the effective displacement is determined according to a standard displacement of the engine and a valve timing position of an intake valve in the target cylinder.

A fifth determining unit 30122, configured to determine, according to the number of times the target cylinder is operated and the second intake air amount, a second air amount entering an exhaust system of the engine during a process in which the target cylinder enters the cylinder deactivation state.

Optionally, the determining module 302 includes:

the first determining submodule 3021 is configured to determine a limit value of an air quantity in the exhaust system of the engine according to a current exhaust manifold pressure of the engine and an effective volume of the exhaust system.

The first processing submodule 3022 is configured to, when the total gas amount is greater than the gas amount limit value, use the gas amount limit value as a target gas amount.

And a second processing submodule 3023, configured to take the total gas amount as a target gas amount when the total gas amount is less than or equal to the gas amount limit value.

And the second determining submodule 3024 is configured to determine a target fuel injection quantity according to the target gas quantity.

Optionally, the second determining submodule 3024 includes:

a sixth determining unit 30241, configured to determine a standard fuel injection amount according to the target air amount.

A seventh determining unit 30242, configured to query a preset fourth mapping relationship according to the catalyst temperature of the engine, so as to obtain the combustion efficiency, where the preset fourth mapping relationship is used to describe a mapping relationship between the catalyst temperature and the combustion efficiency.

An eighth determining unit 30243, configured to determine a target fuel injection amount according to the standard fuel injection amount and the combustion efficiency.

Optionally, the control module 303 includes:

and the third determining submodule 3031 is configured to determine the first fuel injection frequency according to a ratio between the target fuel injection quantity and the single fuel injection quantity of the fuel injector.

And the third processing submodule 3032 is configured to round the first oil injection frequency according to a preset carry system to obtain a second oil injection frequency.

And the control submodule 3033 is used for controlling the oil injector of the target cylinder to inject oil according to the second oil injection frequency and the single oil injection quantity.

The embodiment of the invention provides a vehicle emission reduction device, when a target cylinder in a cylinder deactivation state in an engine is switched to a normal state, a fuel injector in the target cylinder is controlled to inject corresponding target fuel injection quantity according to the total gas quantity of the engine entering an exhaust system, so that fuel oil injected by the fuel injector and air in the exhaust system of the engine can be mixed according to the standard ratio of the air and the fuel oil required by a three-way catalyst, and the tail gas treatment efficiency of the three-way catalyst is ensured.

The embodiment of the present invention further provides a vehicle, which may specifically include: the engine control unit described above.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.