CN112412584B

CN112412584B - Method for reducing engine emission, VCU, and control system and vehicle with VCU

Info

Publication number: CN112412584B
Application number: CN201910785650.4A
Authority: CN
Inventors: 陈欢; 徐政; 程传辉; 武涛; 杜乐; 王琨
Original assignee: SAIC Motor Corp Ltd
Current assignee: SAIC Motor Corp Ltd
Priority date: 2019-08-23
Filing date: 2019-08-23
Publication date: 2022-03-25
Anticipated expiration: 2039-08-23
Also published as: CN112412584A

Abstract

The invention discloses a method for reducing engine emission, a VCU, a control system with the VCU and a vehicle, wherein the method is used for a catalyst of an exhaust system of the vehicle and is configured as follows: and taking a pre-starting command sent by a user remotely as an activation condition for preheating a catalyst carrier of the catalyst, and outputting a preheating control command to a control end of a carrier heater to enable the catalyst carrier to reach or approach the working temperature before the engine is started. By applying the scheme, the catalyst carrier can be heated to the working temperature before the engine is started, so that the emission generated in the starting process of the engine is completely subjected to catalytic conversion, and the pollutant emission is effectively controlled; meanwhile, the emission of pollutants can be effectively controlled on the basis of not increasing the cost of vehicles without additionally increasing hardware equipment.

Description

Method for reducing engine emission, VCU, and control system and vehicle with VCU

Technical Field

The invention relates to the technical field of emission control of internal combustion engines, in particular to a method for reducing engine emission, a VCU, a control system with the VCU and a vehicle.

Background

It is known that in the initial stage of starting of an engine in a cold state, the mixture of oil and gas is poor, and the temperature of a carrier of a three-way catalyst is low during starting, so that the three-way catalyst does not have catalytic conversion capacity, and in the state, more cold-start emission pollutants are generated.

To solve this problem, the prior art proposes to accelerate the temperature rise rate of the catalyst carrier after the engine is started by electrically heating the catalyst so that the catalyst carrier rapidly enters the operating state, thereby reducing the cold start emissions of the engine. However, the prior art scheme starts to work after the engine is started, and the catalytic converter carrier is heated to the temperature before normal catalytic conversion, so that the remarkable HC emission generated at the moment of cold start cannot be subjected to catalytic conversion and is directly discharged into the atmosphere, thereby causing adverse effects on the environment.

In view of the above, it is desirable to optimize the heating control of the existing catalyst to effectively control the pollutant emission during the engine starting process.

Disclosure of Invention

In order to solve the technical problems, the invention provides a method for reducing the emission of an engine, a VCU, a control system with the VCU and a vehicle.

The invention provides a method for reducing engine emission, which is used for a catalyst of a vehicle exhaust system and is configured to: and taking a pre-starting command sent by a user remotely as an activation condition for preheating a catalyst carrier of the catalyst, and outputting a preheating control command to a control end of a carrier heater to enable the catalyst carrier to reach or approach the working temperature before the engine is started.

Preferably, the outputting the preheating control command to the control terminal of the carrier heater includes: and acquiring user geographical position information and vehicle geographical position information when a user remotely sends a starting instruction, and outputting the preheating control instruction according to the user geographical position information and the vehicle geographical position information.

Preferably, the outputting the preheating control command to the control terminal of the carrier heater further comprises: the method comprises the steps of obtaining the moving speed of a user and the current carrier temperature of a catalyst, and outputting a preheating control command according to the geographical position information of the user, the geographical position information of a vehicle, the moving speed and the carrier temperature, wherein the preheating control command comprises command sending time and command signals representing the heating power of a carrier heater.

Preferably, the outputting the preheating control instruction according to the user geographical position information, the vehicle geographical position information, the moving speed and the carrier temperature comprises: determining a second time length for the user to reach the vehicle according to the user geographical position information, the vehicle geographical position information and the moving speed, determining a first time length for heating the catalyst carrier to reach or be close to the working temperature according to the carrier temperature and the normal heating power of the carrier heater, and outputting the preheating control command according to the second time length and the first time length.

Preferably, when the second time length is less than the first time length, the instruction signal indicates that the carrier heater is preheated at a high heating power.

Preferably, engine start is taken as a condition for reducing the heating power of the substrate heater, and the substrate temperature of the catalyst and/or the inlet temperature of the catalyst reaches the operating temperature as an end condition for warming up the catalyst substrate.

The invention provides a vehicle VCU, which can execute a method for reducing engine emission of a catalyst of a vehicle exhaust system, and is configured to: the method is configured to: and taking a pre-starting command sent by a user remotely as an activation condition for preheating a catalyst carrier of the catalyst, and outputting a preheating control command to a control end of a carrier heater to enable the catalyst carrier to reach or approach the working temperature before the engine is started.

The invention provides a vehicle control system, which comprises a vehicle VCU, a catalyst arranged at the downstream side of an engine exhaust pipe and a carrier heater thereof, and further comprises: the mobile terminal is used for remotely sending a pre-starting instruction; the vehicular VCU is specifically a vehicular VCU as described previously.

Preferably, the mobile terminal is a smart phone or a smart car key.

Preferably, the pre-start command is a separate operation command or is integrated with a vehicle unlock command.

Preferably, the communication between the mobile terminal and the vehicle VCU is direct communication or indirect communication based on a wireless network or a radio frequency signal.

Preferably, the carrier heater is an electric heater powered by an on-board battery and has at least a normal heating power and a high heating power.

Preferably, the method further comprises the following steps: the carrier temperature sensor is used for collecting the carrier temperature of the catalyst; and the exhaust temperature sensor is used for collecting the inlet temperature of the catalyst.

The invention provides a vehicle comprising the vehicle control system.

Preferably, the vehicle is a fuel vehicle or a hybrid vehicle.

Compared with the prior art, the invention develops a new method for heating the catalyst in advance, namely heating the catalyst carrier to the temperature capable of carrying out catalytic conversion before the engine is started. Specifically, a pre-starting command sent remotely by a user is used as an activation condition for preheating the catalyst carrier, and a preheating control command is output to a control end of a carrier heater, so that the catalyst carrier reaches or approaches to the working temperature before the engine is started. So set up, can carry out catalytic conversion completely with the emission that the engine start-up process produced, provide reliable guarantee for effectively reducing the emission pollutant of engine. In addition, the scheme does not need to additionally increase hardware equipment, and the vehicle cost cannot be increased on the basis of effectively controlling the emission of pollutants.

In a preferred aspect of the present invention, the warm-up control instruction is output based on the user geographical location information and the vehicle geographical location information to predict a time at which the catalyst carrier is heated up in advance, and the catalyst carrier is heated up to the operating temperature accurately before the engine is started; furthermore, a preheating control command is issued by combining the moving speed and the carrier temperature, and when the time for a user to arrive at the vehicle is less than the time required by normal heating, the carrier heater is controlled to preheat at high heating power. So set up, when satisfying minimum heating electric energy consumption, reasonable time of prejudging catalyst carrier heating to heat the catalyst carrier in advance and be close to or reach the temperature of normal work. The method has the characteristics of reliable operation and stable performance.

Drawings

FIG. 1 is a schematic diagram of a vehicle control system according to an embodiment;

FIG. 2 is a schematic diagram of the electrically heated catalyst according to an embodiment;

FIG. 3 is a block diagram of a method for reducing engine emissions according to an embodiment.

In the figure:

air cleaner 1, intake pipe 2, engine 3, exhaust pipe 4, catalyst 5, vehicle temperature sensor 6, vehicle-mounted battery 7, vehicle VCU8, mobile terminal 9, user 10, vehicle 11, vehicle heater 12, catalyst support 13, exhaust temperature sensor 14.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

Without loss of generality, the present embodiment is directed to an automobile with a catalyst disposed in an exhaust system as a description subject, and innovatively proposes a method for reducing engine emissions based on the heating function of the catalyst carrier in the prior art, please refer to a schematic diagram of a Vehicle Control system shown in fig. 1, where the Control system includes a Vehicle VCU (Vehicle Control Unit) 8, a catalyst 5 disposed on the downstream side of an engine exhaust pipe 4, and a carrier heater 12 thereof. As in the prior art, a catalyst is attached to the inner catalyst carrier 13 of the catalyst 5 to convert harmful gases such as CO, HC, and NOx emitted from automobile exhaust into harmless carbon dioxide, water, and nitrogen by oxidation and reduction. It should be understood that the specific implementation of the catalyst does not constitute a substantial limitation on the technical solution claimed in the present application.

The method for reducing the engine emission provided by the embodiment is specifically configured as follows: the pre-start command remotely issued by the user 10 is used as an activation condition for preheating the catalyst carrier 13 of the catalyst 5, and the preheating control command is output to the control end of the carrier heater 12, so that the catalyst carrier 13 reaches or approaches the working temperature before the engine 3 is started. The "operating temperature" herein refers to a temperature at which the catalyst carrier 13 normally operates, and is generally set to a temperature corresponding to a conversion efficiency of the catalyst of 90%.

After the engine 3 is started, external air enters a working cavity of the engine 3 through the air filter 1 and the air inlet pipe 2, emissions generated in the starting process enter the catalyst 5 through the exhaust pipe 4, and at the moment, the catalyst carrier 13 reaches or approaches to the working temperature, so that the emissions generated in the starting process are completely subjected to catalytic conversion, and reliable guarantee is provided for effectively reducing the emission pollutants of the engine. The scheme does not need to additionally increase hardware equipment, and can effectively control the emission of pollutants on the basis of not increasing the cost of vehicles.

The carrier heater 12 is preferably in the form of a heating plate, and reference is also made to fig. 2, which shows a schematic view of the electrically heated catalytic converter. As shown in fig. 1 and 2 in combination, the carrier heater is preferably an electric heater powered by an on-board battery 7 and having at least normal heating power and high heating power. In addition to the normal heating power, the storage battery can be preheated in a manner of different output currents, and the carrier heaters 12 with different powers have different heating speeds. It is to be understood that the catalyst heater sheet may be disposed at the front end of the catalyst carrier 13, and the disposition area and range may be selected according to the actual requirements of the vehicle, rather than being limited to the case where the entire catalyst carrier 13 is heated.

Specifically, the user 10 may remotely issue the pre-boot instruction through the mobile terminal 9; the mobile terminal 9 is a smart phone or a smart car key. Of course, the mobile terminal 9 may be other forms of intelligent terminal devices, such as, but not limited to, a computer installed with a communication application program that establishes communication with the vehicle VCU, and reliably implement communication and data processing with the vehicle VCU based on the intelligent networking technology, and also can satisfy the issue of the basic pre-start instruction.

It should be noted that the pre-start command is an operation command sent separately, and may also be sent integrally with the vehicle unlock command, as long as the command for preheating the catalyst carrier can be issued in advance is within the scope of the present application. Here, the wireless communication between the mobile terminal 9 and the vehicle VCU8 may be in the form of network signal transmission, or in the form of short-distance radio frequency signals, and may be direct communication with each other, or in an indirect communication mode including intermediate transfer.

In order to accurately heat the catalyst carrier to the operating temperature, the location where the user 10 remotely issues the start command and the location where the vehicle 11 is located may be considered in the control strategy. Specifically, user geographical position information and vehicle geographical position information when a user remotely sends a starting instruction are obtained, and the preheating control instruction is output according to the user geographical position information and the vehicle geographical position information; the corresponding geographical displacement information can be acquired in real time by using the GPS positioning systems of the mobile terminal 9 and the vehicle 11. That is, the actual physical distance that the user moves to the vehicle is fully considered.

Referring further to FIG. 2, FIG. 2 shows a block diagram of the method for reducing engine emissions.

Here, the user movement speed and the current catalyst substrate temperature are further taken into account in the control strategy to more accurately determine the output warm-up control command, such as but not limited to a command signal including a command issuance time and a heating power characteristic of the substrate heater. And outputting a corresponding preheating control instruction according to the user geographical position information, the vehicle geographical position information, the moving speed and the carrier temperature by acquiring the moving speed of the user and the current carrier temperature of the catalyst. The GPS positioning application matched with the mobile terminal 9 can determine the moving speed of the user in real time, and the carrier temperature sensor 6 is used for acquiring the carrier temperature of the catalyst 5 in real time. The substrate temperature sensor 6 is preferably arranged in the front end region of the catalyst substrate 13 so that good catalytic conversion capability can be obtained at a position upstream of the exhaust path.

Specifically, a first time length t1 for heating the catalyst carrier to reach or approach the operating temperature is determined with the current carrier temperature and the normal heating power of the carrier heater, a second time length t2 for the user to reach the vehicle is determined with the user geographical position information, the vehicle geographical position information and the moving speed, and the warm-up control command is output with the second time length t2 and the first time length t 2.

When t1< t2, the catalyst 5 is not warmed up for a while to save electric power.

When t1 equals t2, the vehicle VCU8 controls the battery 7 to supply power to the catalyst heater 12, so as to heat the catalyst carrier 13 inside the catalyst 5 at a normal warm-up rate, that is, when the user 10 arrives at the position of the vehicle 11, the catalyst 5 is just in a state of being able to operate with full catalytic reduction; next, the vehicle VCU8 reduces the supply current to the carrier heater 12 so that the temperature of the catalyst carrier 13 can be maintained near the operating temperature based on the engine exhaust gas temperature, resulting in good catalytic conversion capability. That is, engine startup is taken as a condition for reducing the heating power of the carrier heater to save electric power.

When t1> t2, the command signal indicates that the carrier heater is warming up at high heating power. Specifically, the vehicle VCU8 controls the battery 7 to supply the carrier heater 12 with a larger or maximum capacity according to the extent that the first time period t1 is higher than the second time period t2, that is, the high heating power can be correspondingly graded, so as to heat the catalyst carrier 13 inside the catalyst 5 with a larger or maximum heating capacity, so as to ensure that the temperature of the catalyst carrier 13 inside the catalyst 5 can approach or reach the working temperature when the engine 3 starts to start, so that the vehicle VCU8 has a good catalytic conversion capacity, and can effectively reduce the pollutant emission generated during the cold start of the engine.

Preferably, the end condition for preheating the catalyst carrier 13 is set to the operating temperature reached by the carrier temperature of the catalyst 5 and/or the inlet temperature of the catalyst 5. Wherein the system may use an exhaust gas temperature sensor 14 to collect the inlet temperature of the catalyst 5, as shown in fig. 2, preferably installed near the inlet of the catalyst 5 to obtain a relatively accurate temperature value. As shown in connection with fig. 3, when the engine exhaust temperature is greater than the operating temperature of the catalyst support 13, the vehicle VCU8 stops providing current to the support heater 12 and the heat carried by the engine exhaust continues to preheat the catalyst 13 so that the temperature of the catalyst support 13 is always above the operating temperature, maintaining efficient conversion efficiency.

The present embodiments also provide a vehicle VCU that can perform the aforementioned method for reducing engine emissions for a catalyst of an exhaust system of a vehicle, the method configured to: the method is configured to: and taking a pre-starting command sent by a user remotely as an activation condition for preheating a catalyst carrier of the catalyst, and outputting a preheating control command to a control end of a carrier heater to enable the catalyst carrier to reach or approach the working temperature before the engine is started. The implementation of other functional principles of the vehicle VCU is not the core invention point of the present application, and those skilled in the art can implement the same by using the prior art, so that the detailed description thereof is omitted.

The embodiment also provides a vehicle comprising the vehicle control system. The vehicle can be a fuel vehicle or a hybrid vehicle, and similarly, other functional components of the vehicle are not the core invention points of the present application, and can be realized by adopting the prior art by a person skilled in the art, so that the details are not described herein. Such as, but not limited to, a car, motorcycle, or truck.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements should also be considered as the protection scope of the present invention.

Claims

1. A method of reducing engine emissions for a catalyst of an exhaust system of a vehicle, the method configured to: taking a pre-starting command sent by a user remotely as an activation condition for preheating a catalyst carrier, and outputting a preheating control command to a control end of a carrier heater to enable the catalyst carrier to reach or approach a working temperature before an engine is started; the outputting of the preheating control command to the control terminal of the carrier heater includes: acquiring user geographical position information and vehicle geographical position information when a user remotely sends a starting instruction, and outputting the preheating control instruction according to the user geographical position information and the vehicle geographical position information;

the outputting of the preheating control command to the control end of the carrier heater further comprises: acquiring the moving speed of a user and the current carrier temperature of a catalyst, and outputting a preheating control instruction according to the geographical position information of the user, the geographical position information of a vehicle, the moving speed and the carrier temperature, wherein the preheating control instruction comprises instruction sending time and an instruction signal representing the heating power of a carrier heater;

the outputting the preheating control instruction according to the user geographical position information, the vehicle geographical position information, the moving speed and the carrier temperature comprises:

determining a second time length for the user to reach the vehicle according to the user geographical position information, the vehicle geographical position information and the moving speed, determining a first time length for heating the catalyst carrier to reach or be close to the working temperature according to the carrier temperature and the normal heating power of the carrier heater, and outputting the preheating control command according to the second time length and the first time length.

2. The method of reducing engine emissions according to claim 1, wherein the command signal is indicative of the carrier heater warming up at a high heating power when the second length of time is less than the first length of time.

3. Method for reducing engine emissions according to claim 1 or 2, characterised in that engine start-up is taken as a condition for reducing the heating power of the substrate heater and the substrate temperature of the catalyst and/or the inlet temperature of the catalyst reaching the operating temperature is taken as an end condition for the catalyst substrate warming-up.

4. A vehicle VCU that implements a method for reducing engine emissions for a catalyst of a vehicle exhaust system, the method configured to: taking a pre-starting command sent by a user remotely as an activation condition for preheating a catalyst carrier of the catalyst, and outputting a preheating control command to a control end of a carrier heater to enable the catalyst carrier to reach or approach a working temperature before an engine is started; the outputting of the preheating control command to the control terminal of the carrier heater includes: acquiring user geographical position information and vehicle geographical position information when a user remotely sends a starting instruction, and outputting the preheating control instruction according to the user geographical position information and the vehicle geographical position information;

5. The vehicular VCU of claim 4, wherein the command signal indicates that the carrier heater is warming up at a high heating power when the second length of time is less than the first length of time.

6. The vehicular VCU according to claim 4 or 5, wherein engine start is used as a condition for reducing the heating power of the carrier heater, and the carrier temperature of the catalyst and/or the inlet temperature of the catalyst reaches the operating temperature as an end condition for warming up the catalyst carrier.

7. A vehicle control system comprising a vehicle VCU and a catalyst and its carrier heater disposed on the downstream side of an engine exhaust pipe, characterized by further comprising:

the mobile terminal is used for remotely sending a pre-starting instruction;

the vehicular VCU is in particular the vehicular VCU of any one of claims 4 to 6.

8. The vehicle control system of claim 7, wherein the mobile terminal is a smart phone or a smart car key.

9. The vehicle control system of claim 8, wherein the pre-start command is a separate operation command or is integrated with a vehicle unlock command.

10. The vehicle control system of claim 7, wherein the communication between the mobile terminal and the vehicle VCU is direct communication or indirect communication based on a wireless network or radio frequency signals.

11. The vehicle control system of claim 7, wherein the carrier heater is an electric heater powered by an on-board battery and having at least a normal heating power and a high heating power.

12. The vehicle control system according to claim 11, characterized by further comprising:

the carrier temperature sensor is used for collecting the carrier temperature of the catalyst;

and the exhaust temperature sensor is used for collecting the inlet temperature of the catalyst.

13. A vehicle characterized by comprising the vehicle control system of any one of claims 7 to 12.

14. The vehicle of claim 13, characterized in that the vehicle is a fuel vehicle, a hybrid vehicle.