阅读说明：本技术 一种车辆换挡控制方法及装置 (Vehicle gear shifting control method and device ) 是由 王继磊 赵甲运 李建东 赵伟 甄雷 于 2019-09-30 设计创作，主要内容包括：本发明提供一种车辆换挡控制方法,包括：在车辆处于匀速状态下,确定车辆的发动机的运行模式；如果发动机处于针对SCR的加热模式,则根据发动机的工况确定发动机是否处于预先标定的排温异常区域；如果发动机处于排温异常区域,则确定SCR当前的转换效率,确定在对变速箱进行档位调整后SCR的预测转换效率；比较SCR当前的转换效率和预测转换效率,得到比较结果；在比较结果满足预设条件时,对变速箱进行档位调整。基于本发明提供的技术方案,能够保证后处理系统针对发动机排气的处理达到最佳状态,提高车辆的尾气排放的一致性。(The invention provides a vehicle gear shifting control method, which comprises the following steps: determining the running mode of an engine of the vehicle when the vehicle is in a constant speed state; if the engine is in a heating mode aiming at the SCR, determining whether the engine is in a pre-calibrated exhaust temperature abnormal area or not according to the working condition of the engine; if the engine is in the abnormal exhaust temperature area, determining the current conversion efficiency of the SCR, and determining the predicted conversion efficiency of the SCR after gear adjustment is carried out on the gearbox; comparing the current conversion efficiency and the predicted conversion efficiency of the SCR to obtain a comparison result; and when the comparison result meets a preset condition, gear adjustment is carried out on the gearbox. Based on the technical scheme provided by the invention, the aftertreatment system can be ensured to reach the optimal state aiming at the treatment of the engine exhaust, and the consistency of the exhaust emission of the vehicle is improved.)

1. A vehicle shift control method, the vehicle being equipped with an aftertreatment system including at least an SCR selective catalytic reduction catalyst, the method comprising:

determining an operation mode of an engine of the vehicle when the vehicle is in a constant speed state;

if the engine is in a heating mode aiming at the SCR, determining whether the engine is in a pre-calibrated exhaust temperature abnormal area or not according to the working condition of the engine;

if the engine is in the abnormal exhaust temperature area, determining the current conversion efficiency of the SCR, and determining the predicted conversion efficiency of the SCR after gear adjustment is carried out on a gearbox;

comparing the current conversion efficiency and the predicted conversion efficiency of the SCR to obtain a comparison result;

and when the comparison result meets a preset condition, performing gear adjustment on the gearbox, wherein the preset condition at least indicates that the predicted conversion efficiency of the SCR is greater than the current conversion efficiency of the SCR.

2. The method according to claim 1, wherein the preset condition is: and the predicted conversion efficiency of the SCR reaches a preset improvement amplitude relative to the current conversion efficiency of the SCR.

3. The method of claim 1 or 2, wherein said determining the current conversion efficiency of the SCR comprises:

determining the current intake air temperature of the SCR;

and determining the current conversion efficiency of the SCR according to the current intake air temperature of the SCR.

4. The method of claim 3, wherein said determining the current intake air temperature of the SCR comprises:

determining the current rotating speed and torque of the engine;

determining the current air inlet temperature of the SCR according to the current rotating speed and torque of the engine;

alternatively, the first and second electrodes may be,

and obtaining a temperature detection value generated by a temperature sensor arranged at the air inlet end of the SCR.

5. The method of claim 3, wherein determining the predicted conversion efficiency of the SCR after gear shifting the transmission comprises:

determining a predicted torque and a predicted speed of the engine after a gear adjustment of the gearbox is performed;

determining a predicted intake air temperature of the SCR according to the predicted rotating speed and the predicted torque of the engine;

and determining the predicted conversion efficiency of the SCR according to the predicted inlet air temperature of the SCR.

6. A shift control device for a vehicle equipped with an aftertreatment system including at least an SCR catalyst, the device comprising:

the running mode determining unit is used for determining the running mode of an engine of the vehicle when the vehicle is in a constant speed state;

the abnormality determination unit is used for determining whether the engine is in a pre-calibrated abnormal exhaust temperature region according to the working condition of the engine if the engine is in a heating mode aiming at SCR;

the conversion efficiency determining unit is used for determining the current conversion efficiency of the SCR and determining the predicted conversion efficiency of the SCR after gear adjustment is carried out on a gearbox if the engine is in the abnormal exhaust temperature region;

the comparison unit is used for comparing the current conversion efficiency and the predicted conversion efficiency of the SCR to obtain a comparison result;

and the control unit is used for adjusting the gear of the gearbox when the comparison result meets a preset condition, wherein the preset condition at least indicates that the predicted conversion efficiency of the SCR is greater than the current conversion efficiency of the SCR.

7. The apparatus of claim 6, wherein the preset condition is: and the predicted conversion efficiency of the SCR reaches a preset improvement amplitude relative to the current conversion efficiency of the SCR.

8. The device according to claim 6 or 7, wherein the conversion efficiency determination unit, in determining the current conversion efficiency of the SCR, is specifically configured to:

determining the current intake air temperature of the SCR; and determining the current conversion efficiency of the SCR according to the current intake air temperature of the SCR.

9. The device according to claim 8, characterized in that the conversion efficiency determination unit, in determining the current intake air temperature of the SCR, is specifically configured to:

determining the current rotating speed and torque of the engine; determining the current air inlet temperature of the SCR according to the current rotating speed and torque of the engine;

alternatively, a temperature detection value generated by a temperature sensor provided at an intake end of the SCR is obtained.

10. The arrangement according to claim 8, characterized in that the conversion efficiency determination unit, in determining the predicted conversion efficiency of the SCR after gear adjustment of the gearbox, is specifically adapted to:

determining a predicted torque and a predicted speed of the engine after a gear adjustment of the gearbox is performed; determining a predicted intake air temperature of the SCR according to the predicted rotating speed and the predicted torque of the engine; and determining the predicted conversion efficiency of the SCR according to the predicted inlet air temperature of the SCR.

Technical Field

The invention relates to the technical field of vehicle control, in particular to a vehicle gear shifting control method and device.

Background

In order to protect the environment, the emission requirements for vehicle exhaust are higher and higher, and the national six-emission standard is newly launched. In order to ensure that the exhaust gas of the vehicle can meet the national emission standards, an after-treatment system is generally arranged in the vehicle. The main function of the aftertreatment system is to reduce nitrogen oxides and particulate matter in the diesel exhaust.

The applicant has found that in vehicles designed for the national emission standards, when the vehicle gears are different, the treatment effect of the aftertreatment system on the engine exhaust gas is greatly different.

Disclosure of Invention

In view of this, embodiments of the present invention provide a vehicle shift control method and apparatus, which ensure that an aftertreatment system can reach an optimal state for engine exhaust gas treatment by adjusting a vehicle gear, and improve consistency of exhaust emission of a vehicle.

In order to achieve the above purpose, the embodiments of the present invention provide the following technical solutions:

in one aspect, the present disclosure provides a shift control method for a vehicle equipped with an aftertreatment system including at least an SCR selective catalytic reduction catalyst, the method comprising:

determining an operation mode of an engine of the vehicle when the vehicle is in a constant speed state;

if the engine is in a heating mode aiming at SCR, determining whether the engine is in a pre-calibrated abnormal exhaust temperature region according to the working condition of the engine;

if the engine is in the abnormal exhaust temperature area, determining the current conversion efficiency of the SCR, and determining the predicted conversion efficiency of the SCR after gear adjustment is carried out on a gearbox;

comparing the current conversion efficiency and the predicted conversion efficiency of the SCR to obtain a comparison result;

and when the comparison result meets a preset condition, performing gear adjustment on the gearbox, wherein the preset condition at least indicates that the predicted conversion efficiency of the SCR is greater than the current conversion efficiency of the SCR.

Optionally, the preset conditions are: and the predicted conversion efficiency of the SCR reaches a preset improvement amplitude relative to the current conversion efficiency of the SCR.

Optionally, the determining the current conversion efficiency of the SCR includes:

determining the current intake air temperature of the SCR;

and determining the current conversion efficiency of the SCR according to the current intake air temperature of the SCR.

Optionally, the determining the current intake air temperature of the SCR includes:

determining the current rotating speed and torque of the engine;

determining the current air inlet temperature of the SCR according to the current rotating speed and torque of the engine;

alternatively, the first and second electrodes may be,

and obtaining a temperature detection value generated by a temperature sensor arranged at the air inlet end of the SCR.

Optionally, the determining the predicted conversion efficiency of the SCR after gear adjustment of the transmission includes:

determining a predicted torque and a predicted speed of the engine after a gear adjustment of the gearbox is performed;

determining a predicted intake air temperature of the SCR according to the predicted rotating speed and the predicted torque of the engine;

and determining the predicted conversion efficiency of the SCR according to the predicted inlet air temperature of the SCR.

In another aspect, the present invention provides a shift control device for a vehicle equipped with an aftertreatment system including at least an SCR selective catalytic reduction catalyst, the device comprising:

the running mode determining unit is used for determining the running mode of an engine of the vehicle when the vehicle is in a constant speed state;

the abnormality determination unit is used for determining whether the engine is in a pre-calibrated abnormal exhaust temperature region according to the working condition of the engine if the engine is in a heating mode aiming at SCR;

the conversion efficiency determining unit is used for determining the current conversion efficiency of the SCR and determining the predicted conversion efficiency of the SCR after gear adjustment is carried out on a gearbox if the engine is in the abnormal exhaust temperature region;

the comparison unit is used for comparing the current conversion efficiency and the predicted conversion efficiency of the SCR to obtain a comparison result;

and the control unit is used for adjusting the gear of the gearbox when the comparison result meets a preset condition, wherein the preset condition at least indicates that the predicted conversion efficiency of the SCR is greater than the current conversion efficiency of the SCR.

Optionally, the conversion efficiency determining unit is specifically configured to, in terms of determining the current conversion efficiency of the SCR:

determining the current intake air temperature of the SCR; and determining the current conversion efficiency of the SCR according to the current intake air temperature of the SCR.

Optionally, the conversion efficiency determining unit is specifically configured to, in terms of determining the current intake air temperature of the SCR:

determining the current rotating speed and torque of the engine; determining the current air inlet temperature of the SCR according to the current rotating speed and torque of the engine;

alternatively, a temperature detection value generated by a temperature sensor provided at an intake end of the SCR is obtained.

Optionally, the conversion efficiency determining unit is specifically configured to, in terms of determining the predicted conversion efficiency of the SCR after gear adjustment of the transmission:

determining a predicted torque and a predicted speed of the engine after a gear adjustment of the gearbox is performed; determining a predicted intake air temperature of the SCR according to the predicted rotating speed and the predicted torque of the engine; and determining the predicted conversion efficiency of the SCR according to the predicted inlet air temperature of the SCR.

The vehicle gear shifting control method disclosed by the invention can be seen in that a temperature exhaust abnormal area is calibrated in advance, whether the engine is in the temperature exhaust abnormal area calibrated in advance is determined according to the working condition of the engine under the condition that the vehicle is in a constant speed state and the engine is in a heating mode aiming at the SCR, if the engine is in the temperature exhaust abnormal area calibrated in advance, the current conversion efficiency of the SCR is determined, and the predicted conversion efficiency of the SCR after the gear adjustment is carried out on the gearbox, and if the predicted conversion efficiency of the SCR is compared with the current conversion efficiency of the SCR and at least the predicted conversion efficiency of the SCR is higher than the current conversion efficiency of the SCR, the gear adjustment is carried out on the gearbox, so that the conversion efficiency of the SCR is improved, the optimal state of the aftertreatment system aiming at the exhaust gas of the engine can be ensured, and the consistency of the.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a flow chart of a vehicle shift control method disclosed herein;

FIG. 2 is a schematic illustration of an abnormal exhaust temperature region of an engine disclosed herein;

FIG. 3 is a flow chart of a method of determining the current conversion efficiency of an SCR in accordance with the present disclosure;

FIG. 4 is a flow chart of a method of determining predicted conversion efficiency of an SCR in accordance with the present disclosure;

FIG. 5 is a flow chart of another disclosed vehicle shift control method;

fig. 6 is a schematic structural diagram of a vehicle gear shift control device disclosed by the invention.

Detailed Description

The operation of the engine will first be briefly described.

After entering from the air filter, the air is pressurized by the turbocharger and enters each cylinder of the engine through the intercooler. Fuel oil is injected into the cylinder through the fuel injector, and the fuel oil is mixed with air in the cylinder to form oil-gas mixture. The cylinder compresses the oil-gas mixture to generate heat energy, so that the oil-gas mixture is ignited. The oil-gas mixture is combusted to produce exhaust. The exhaust gas enters the aftertreatment system through the turbocharger, and the exhaust gas is treated by the aftertreatment system.

SCR is an important component of an aftertreatment system. The SCR functions as follows: under the action of catalyst, the ammonia gas and nitrogen oxide in the exhausted gas are reduced to produce harmless nitrogen and water. The intake air temperature of the SCR can have a significant effect on the conversion efficiency of the SCR on nitrogen oxides, thereby affecting the treatment effect of the aftertreatment system on the exhaust.

In a vehicle designed and produced according to the national six-emission standard, a heating mode aiming at SCR is provided, and the purpose is to improve the intake air temperature of the SCR so as to ensure that the SCR has higher conversion efficiency on nitrogen oxides. The heating mode for SCR mainly includes the following thermal management measures: the opening degree of an air inlet valve throttle valve of the engine is reduced, the in-cylinder back injection of the engine is increased, and combustion parameters are changed.

The applicant finds that, in a vehicle designed according to the national emission standards, when the vehicle gears are different, the treatment effect of the aftertreatment system on the engine exhaust gas is greatly different, and the fundamental reason is that:

in vehicles designed for the national six emission standards, an SCR heating mode is provided, and after the heating mode is turned on, various thermal management measures are initiated, which results in the turbocharger exhaust gas temperature no longer being linear with changes in engine speed and load. This is different from the linear relationship between the exhaust temperature of the turbocharger and the engine speed and load under the national fourth and fifth emission standards.

For example, in some operating regions, the exhaust temperature of the turbocharger is higher when the engine is in a low speed and low load state than when the engine is in a high speed and high load state, which is a phenomenon completely contrary to the conventional knowledge. When the gears of the vehicle are different, the conversion efficiency of the SCR to the nitrogen oxide compound is greatly different, so that the treatment effect of the aftertreatment system to the exhaust is greatly different, and the consistency of the exhaust emission cannot be ensured.

Based on the discovery, the invention discloses a vehicle gear shifting control method and device, which can ensure that the post-treatment system can reach the optimal state aiming at the treatment of the engine exhaust by adjusting the vehicle gear, and improve the consistency of the exhaust emission of the vehicle.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the present invention, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Referring to fig. 1, fig. 1 is a flowchart illustrating a vehicle shift control method according to the present disclosure. The vehicle is equipped with an aftertreatment system that includes at least an SCR. The method comprises the following steps:

s101: and determining the running mode of the engine of the vehicle when the vehicle is in a constant speed state.

In the implementation, the speed of the whole vehicle is analyzed to determine whether the speed is uniform.

It should be noted that, when the vehicle is in a constant speed state, the following is meant: the rate of change of the vehicle speed is within the allowable range. That is, if the rate of change of the vehicle speed is within the allowable range, it is determined that the vehicle is in a constant speed state.

S102: if the engine is in the heating mode for the SCR, whether the engine is in a pre-calibrated exhaust temperature abnormal region is determined according to the working condition of the engine.

And further determining the running mode of the engine when the vehicle is in a constant speed state, and if the engine is in a heating mode aiming at the SCR, further determining whether the engine is in a preset exhaust temperature abnormal region according to the working condition of the engine. The operating conditions of the engine include the speed and torque of the engine.

In the implementation, the abnormal exhaust temperature region of the engine is calibrated in advance through experimental means. The exhaust temperature abnormal area is calibrated by an engine abnormal rotating speed interval and an abnormal torque interval.

Determining whether the engine is in a pre-calibrated exhaust temperature abnormal area according to the working condition of the engine, comprising the following steps: judging whether the rotating speed of the engine is in an engine abnormal rotating speed area of the exhaust temperature abnormal area, judging whether the torque of the engine is in an engine abnormal torque area of the exhaust temperature abnormal area, if the two judgment results are yes, determining that the engine is in the exhaust temperature abnormal area calibrated in advance, and if only one judgment result is yes, or if the two judgment results are not, determining that the engine is not in the exhaust temperature abnormal area calibrated in advance.

As shown in fig. 2, the horizontal axis is the engine speed, the vertical axis is the engine torque, and the data points in the graph are the turbocharger exhaust temperature corresponding to the engine speed and torque. The region defined by the boxes in fig. 2 is an exhaust temperature abnormal region, which is demarcated by an engine abnormal speed region (1050,2350) and an abnormal torque region (100,400), and it should be noted that fig. 2 is only one example of the exhaust temperature abnormal region.

S103: and if the engine is in the abnormal exhaust temperature region, determining the current conversion efficiency of the SCR, and determining the predicted conversion efficiency of the SCR after gear adjustment is carried out on the gearbox.

If the engine is in an abnormal exhaust temperature region, the current conversion efficiency of the SCR is determined. Additionally, there is a need to determine the predicted conversion efficiency of the SCR after gear shifting of the transmission. It should be noted here that the gear of the gearbox is not actually adjusted in step S103, but the conversion efficiency of the SCR after gear adjustment of the gearbox is assumed to be determined, which is referred to as the predicted conversion efficiency of the SCR.

S104: and comparing the current conversion efficiency and the predicted conversion efficiency of the SCR to obtain a comparison result.

S105: and when the comparison result meets a preset condition, gear adjustment is carried out on the gearbox.

Wherein the preset condition indicates at least: the predicted conversion efficiency of the SCR is greater than the current conversion efficiency of the SCR.

And comparing the current conversion efficiency and the predicted conversion efficiency of the SCR, and if the comparison result meets a preset condition, adjusting the gear of the gearbox.

In one embodiment, the preset conditions are: the predicted conversion efficiency of the SCR is greater than the current conversion efficiency of the SCR.

It should be noted that the gear adjustment for the gearbox in step S105 is the same as the gear adjustment intended for the gearbox in step S103.

In an implementation, determining a predicted conversion efficiency of the SCR after a gear adjustment of the transmission comprises: the predicted conversion efficiency of the SCR after 1 gear upshift and/or 1 gear downshift of the transmission is determined.

In one embodiment, if the engine is in an abnormal exhaust temperature region, the current conversion efficiency of the SCR is determined, the predicted conversion efficiency of the SCR after the first gear adjustment is carried out on the gearbox is determined, and the current conversion efficiency and the predicted conversion efficiency of the SCR are compared to obtain a comparison result. And if the comparison result meets the preset condition, performing first gear adjustment on the gearbox. And if the comparison result does not meet the preset condition, determining the predicted conversion efficiency of the SCR after the second gear adjustment is carried out on the gearbox, and comparing the current conversion efficiency and the predicted conversion efficiency of the SCR to obtain a comparison result. And if the comparison result meets the preset condition, performing second gear adjustment on the gearbox, and if the comparison result does not meet the preset condition, keeping the gear of the gearbox unchanged.

Wherein the first gear is adjusted to one of upshift 1 and downshift 1, and the second gear is adjusted to the other of upshift 1 and downshift 1.

The invention discloses a vehicle gear shifting control method, which comprises the steps of pre-calibrating an abnormal exhaust temperature region, determining whether an engine is in the abnormal exhaust temperature region pre-calibrated according to the working condition of the engine under the condition that the vehicle is in a constant speed state and the engine is in a heating mode aiming at an SCR (Selective catalytic reduction), determining the current conversion efficiency of the SCR if the engine is in the abnormal exhaust temperature region pre-calibrated, and predicting the conversion efficiency of the SCR after gear adjustment is carried out on a gearbox, wherein if the predicted conversion efficiency of the SCR is compared with the current conversion efficiency of the SCR, the condition that the predicted conversion efficiency of the SCR is at least higher than the current conversion efficiency of the SCR is met, gear adjustment is carried out on the gearbox, so that the conversion efficiency of the SCR is improved, the condition that the post-processing system can reach the optimal state aiming at the treatment of.

In another embodiment, the preset condition is configured to: and the predicted conversion efficiency of the SCR reaches a preset improvement range relative to the current conversion efficiency of the SCR.

That is, if the engine is in an abnormal exhaust temperature region, determining the current conversion efficiency of the SCR, determining the predicted conversion efficiency of the SCR after gear adjustment is performed on the transmission, comparing the current conversion efficiency of the SCR with the predicted conversion efficiency, and if the predicted conversion efficiency of the SCR is greater than the current conversion efficiency of the SCR and the predicted conversion efficiency of the SCR reaches a preset boost magnitude (e.g., 2%) relative to the current conversion efficiency of the SCR, gear adjustment is performed on the transmission. Otherwise, the gear of the gearbox remains unchanged.

In the above embodiment, if after the gear adjustment is performed on the gearbox, the conversion efficiency of the SCR can be greatly improved, and then the corresponding gear adjustment is performed on the gearbox, thereby avoiding the problem that the gear of the gearbox is frequently adjusted but the conversion efficiency of the SCR is not obviously improved.

The following describes a process for determining the current conversion efficiency of the SCR with reference to fig. 3, including:

s301: and determining the current intake air temperature of the SCR.

In one possible implementation, the current speed and torque of the engine are determined, and the current intake air temperature of the SCR is determined according to the current speed and torque of the engine.

In the implementation, a corresponding relation between the engine speed and the torque and the SCR air inlet temperature is established in advance, after the current engine speed and the current engine torque are determined, the air inlet temperature corresponding to the current engine speed and the current engine torque is determined according to the pre-established corresponding relation between the engine speed and the torque and the SCR air inlet temperature, and the air inlet temperature is the SCR current air inlet temperature.

In another possible implementation manner, a temperature sensor is arranged at the air inlet end of the SCR, and a temperature detection value generated by the temperature sensor is obtained.

S302: and determining the current conversion efficiency of the SCR according to the current intake air temperature of the SCR.

In the implementation, the corresponding relation between the intake air temperature of the SCR and the conversion efficiency of the SCR is established in advance. After the current air inlet temperature of the SCR is determined, the conversion efficiency corresponding to the current air inlet temperature of the SCR is determined according to the pre-established corresponding relation between the air inlet temperature of the SCR and the conversion efficiency of the SCR, and the conversion efficiency is the current conversion efficiency of the SCR.

The process of determining the predicted conversion efficiency of the SCR after a gear shift of the transmission is explained below with reference to fig. 4, including:

s401: a predicted torque and a predicted speed of the engine after a gear adjustment of the transmission are determined.

And at the moment of gear shifting of the gearbox, the output power of the engine is the same, the vehicle speed is the same, and the rotating speed and the torque of the engine corresponding to the gear-adjusted gearbox are calculated by combining the gear and the speed ratio of the gearbox.

S402: a predicted intake air temperature of the SCR is determined based on a predicted speed and a predicted torque of the engine.

In the implementation, the corresponding relation between the engine speed and the torque and the air inlet temperature of the SCR is established in advance, after the predicted engine speed and the predicted torque of the engine are determined, the air inlet temperature corresponding to the predicted engine speed and the predicted torque of the engine is determined according to the corresponding relation between the engine speed and the torque and the air inlet temperature of the SCR, and the air inlet temperature is the predicted air inlet temperature of the SCR.

S403: the predicted conversion efficiency of the SCR is determined based on the predicted intake air temperature of the SCR.

In the implementation, the corresponding relation between the intake air temperature of the SCR and the conversion efficiency of the SCR is established in advance. After the predicted inlet air temperature of the SCR is determined, the conversion efficiency corresponding to the predicted inlet air temperature of the SCR is determined according to the pre-established corresponding relation between the inlet air temperature of the SCR and the conversion efficiency of the SCR, and the conversion efficiency is the predicted conversion efficiency of the SCR.

The disclosed vehicle shift control method of the present invention is described in more detail below with reference to FIG. 5. The method comprises the following steps:

s501: and analyzing the speed of the whole vehicle.

S502: and judging whether the vehicle is in a constant speed state or not according to the speed of the whole vehicle. And if the vehicle is in the constant speed state, executing the step S503, otherwise, returning to execute the step S501.

S503: an operating mode of the engine is detected.

S504: it is determined whether the engine is in a heating mode for the SCR. If the engine is in the heating mode for SCR, step S505 is executed, otherwise, execution returns to step S503.

S505: and judging whether the engine is in an abnormal exhaust temperature area. If the engine is in the abnormal exhaust temperature region, step S506 is executed, otherwise, step S505 is continuously executed.

S506: the current conversion efficiency of the SCR and a first predicted conversion efficiency of the SCR after a first gear adjustment is carried out on the gearbox are determined.

S507: and judging whether the first predicted conversion efficiency of the SCR reaches 2% relative to the current conversion efficiency of the SCR. If the boosting amplitude reaches 2%, step S508 is executed, otherwise, step S509 is executed.

S508: a first gear adjustment is performed on the gearbox.

S509: and determining the current conversion efficiency of the SCR and a second predicted conversion efficiency of the SCR after a second gear adjustment is carried out on the gearbox.

S510: and judging whether the second predicted conversion efficiency of the SCR reaches 2% relative to the current conversion efficiency of the SCR. If the boosting amplitude reaches 2%, step S511 is performed, otherwise, step S512 is performed.

S511: and carrying out second gear adjustment on the gearbox.

S512: the gearbox maintains the current gear.

Wherein the first gear is adjusted to one of upshift 1 and downshift 1, and the second gear is adjusted to the other of upshift 1 and downshift 1.

The invention discloses a vehicle gear shifting control method and correspondingly discloses a vehicle gear shifting control device. The descriptions of the two in the specification can be mutually referred.

Referring to fig. 6, fig. 6 is a schematic structural diagram of the vehicle shift control device disclosed in the present invention. The vehicle shift control device includes:

an operation mode determination unit 601 for determining an operation mode of an engine of the vehicle when the vehicle is in a constant speed state;

an abnormality determination unit 602, configured to determine whether the engine is in a pre-calibrated exhaust temperature abnormal region according to a working condition of the engine if the engine is in a heating mode for SCR;

a conversion efficiency determination unit 603, configured to determine a current conversion efficiency of the SCR and determine a predicted conversion efficiency of the SCR after gear adjustment is performed on the transmission if the engine is in an abnormal exhaust temperature region;

a comparing unit 604, configured to compare the current conversion efficiency of the SCR with the predicted conversion efficiency to obtain a comparison result;

a control unit 605, configured to perform gear adjustment on the transmission when the comparison result meets a preset condition, where the preset condition at least indicates that the predicted conversion efficiency of the SCR is greater than the current conversion efficiency of the SCR.

The invention discloses a vehicle gear shifting control device, which pre-calibrates an abnormal temperature exhaust area, determines whether an engine is in the abnormal pre-calibrated temperature exhaust area according to the working condition of the engine under the condition that the vehicle is in a constant speed state and the engine is in a heating mode aiming at an SCR (selective catalytic reduction), determines the current conversion efficiency of the SCR if the engine is in the abnormal pre-calibrated temperature exhaust area, and predicts the conversion efficiency of the SCR after gear adjustment is carried out on a gearbox.

Optionally, the preset conditions are: and the predicted conversion efficiency of the SCR reaches a preset improvement range relative to the current conversion efficiency of the SCR.

Optionally, the conversion efficiency determining unit 603 is specifically configured to, in terms of determining the current conversion efficiency of the SCR: determining the current intake air temperature of the SCR; and determining the current conversion efficiency of the SCR according to the current intake air temperature of the SCR.

Optionally, the conversion efficiency determining unit 603 is specifically configured to, in determining the current intake air temperature of the SCR: determining the current rotating speed and torque of the engine; determining the current air inlet temperature of the SCR according to the current rotating speed and torque of the engine; alternatively, a temperature detection value generated by a temperature sensor provided at an intake end of the SCR is obtained.

Optionally, the conversion efficiency determining unit 603 is specifically configured to, in terms of determining the predicted conversion efficiency of the SCR after gear adjustment of the transmission: determining a predicted torque and a predicted rotation speed of the engine after gear adjustment is performed on the gearbox; determining the predicted air inlet temperature of the SCR according to the predicted rotating speed and the predicted torque of the engine; the predicted conversion efficiency of the SCR is determined based on the predicted intake air temperature of the SCR.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the apparatus embodiment, since it is substantially similar to the method embodiment, it is relatively simple to describe, and reference may be made to some descriptions of the method embodiment for relevant points.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.