WO2021190224A1

WO2021190224A1 - Control method and apparatus for variable geometry turbocharger and vehicle

Info

Publication number: WO2021190224A1
Application number: PCT/CN2021/077508
Authority: WO
Inventors: 刘云辉; 晏双鹤; 杨金鹏; 谭振东; 黄松; 陈海岩; 韩子良; 赵普天; 韩广华; 杨中华; 王岩; 顾亚松; 胡宇辰; 谷凌志; 侯文浩; 谷建毅; 付帅飞; 张召; 董清泉; 段正
Original assignee: 长城汽车股份有限公司
Priority date: 2020-03-23
Filing date: 2021-02-23
Publication date: 2021-09-30
Also published as: CN112392590B; CN112392590A

Abstract

Disclosed is a control method for a variable geometry turbocharger. The method is applied to a vehicle, the vehicle comprising an engine which has a variable geometry turbocharger, and the variable geometry turbocharger comprising a nozzle ring. The method comprises: obtaining the current rotational speed and the target torque of the engine; determining the current inflection point opening degree according to the current rotational speed, with the current inflection point opening degree being the opening degree of the nozzle ring for the current rotational speed and allowing the supercharge pressure of the variable geometry turbocharger to reach the maximum value; determining the desired opening degree of the nozzle ring according to the current rotational speed and the target torque; determining the target opening degree of the nozzle ring according to the greater value of the current inflection point opening degree and the desired opening degree; and adjusting the opening degree of the nozzle ring to the target opening degree. The method can prevent a situation where the supercharge pressure cannot be provided due to the sudden rise of the turbine front-end pressure of the turbocharger, and effectively protect the turbocharger. A control device for a variable geometry turbocharger, and a vehicle are further disclosed.

Description

Control method, device and vehicle of variable section turbocharger

Cross-references to related applications

This disclosure requires the priority of a Chinese patent application filed with the Chinese Patent Office with an application number of 202010210096.X and titled "A control method, device and vehicle for a variable-section turbocharger" on March 23, 2020, The entire content is incorporated into this disclosure by reference.

Technical field

The present disclosure relates to the field of automobile technology, and in particular to a control method, device and vehicle of a variable-section turbocharger.

Background technique

At present, variable geometry turbocharger (VGT) can not only increase the power of the engine, but also reduce the emission pollution of the engine, making it widely used in the engine of fuel vehicles.

Unlike traditional wastegate superchargers, VGT has no bypass valve setting. The exhaust gas sucked in directly passes through the turbine, and a set of nozzles that can change the section of the turbine chamber inlet and the blowing direction of the intake air are installed in the volute.环装置。 Ring device. At high speeds, VGT has better fluidity and lower pressure in front of the turbine, which can effectively improve pumping loss, reduce in-cylinder exhaust gas recirculation residuals and improve combustion boundaries, so that the engine's combustion center of gravity is also largely premised; and In the low-speed state, because the ratio of the supercharger flow passage section to the wheel diameter can be reduced by adjusting the nozzle ring opening, the VGT can effectively increase the turbine end flow rate, generate higher boost pressure, and at the same time make its demand The vortex end pressure ratio is reduced, thereby greatly improving pumping loss and knocking, as well as improving fuel economy.

However, the mechanical structure characteristics of VGT also make it happen that the exhaust gas circulation at the turbine end becomes worse during the nozzle ring adjustment process, which causes the turbo-end boost pressure to be unable to build up normally, which will not only affect the normal performance of the engine at low speeds. The output will also reduce the service life of the supercharger.

Overview

In view of this, the present disclosure aims to provide a variable-section turbocharger control method, device, and vehicle, so as to solve the problem that the variable-section turbocharger in the prior art is prone to excessive pressure at the front end of the turbine, resulting in failure. The problem of normal supercharging and affecting the service life of the supercharger.

In order to achieve the above objective, the technical solution of the present disclosure is achieved as follows:

A method for controlling a variable-section turbocharger is applied to a vehicle. The vehicle includes an engine with a variable-section turbocharger, and the variable-section turbocharger includes a nozzle ring, wherein the method include:

Acquiring the current speed and target torque of the engine;

Determine the current opening of the inflection point according to the current rotation speed; the current opening of the inflection point is the opening of the nozzle ring for the current rotation speed and the boost pressure of the variable area turbocharger reaches a maximum value;

Determine the required opening degree of the nozzle ring according to the current speed and the target torque;

Determining the target opening of the nozzle ring according to the larger value of the current inflection point opening and the required opening;

The opening degree of the nozzle ring is adjusted to the target opening degree.

Optionally, in the control method, the adjusting the opening of the nozzle ring to the target opening includes:

Acquiring the current opening degree of the nozzle ring;

Determine the driving duty cycle and driving direction of the nozzle ring according to the current opening degree and the target opening degree, and through a proportional calculus closed-loop adjustment algorithm;

According to the driving duty ratio and the driving direction, the opening degree of the nozzle ring is adjusted to a larger value of the current inflection point opening degree and the required opening degree.

Acquiring the current opening degree of the nozzle ring;

When the current inflection point opening is less than the required opening, according to the current opening and the target opening, and through the proportional calculus closed-loop adjustment algorithm, the driving duty cycle and driving of the nozzle ring are determined direction;

Adjusting the opening degree of the nozzle ring to the target opening degree according to the driving duty ratio and the driving direction;

When the current inflection point opening is greater than or equal to the required opening, the opening of the nozzle ring is adjusted to the target opening.

Optionally, in the control method, the vehicle stores a corresponding relationship between the rotation speed of the engine and the opening of the inflection point, and the corresponding relationship indicates that the engine is at different rotation speeds and the corresponding The opening of the nozzle ring at which the boost pressure of the variable-section turbocharger reaches a maximum value; the determining the current opening of the inflection point according to the current rotation speed includes:

Determine the current inflection point opening degree according to the current rotation speed and the corresponding relationship.

Optionally, in the control method, in the correspondence relationship, the rotation speed is divided into a plurality of rotation speed intervals according to a preset step length, and each of the rotation speed intervals corresponds to an opening degree of the inflection point.

Optionally, use the rotation speed when the engine's external characteristic curve is changed from the constant torque state to the constant power state as the inflection point rotation speed;

When the rotation speed is lower than the inflection point rotation speed, the preset step length is set to 200 revolutions;

When the rotation speed is higher than the inflection point rotation speed, the preset step length is set to 400 revolutions.

Optionally, the determining the required opening degree of the nozzle ring according to the current rotation speed and the target torque includes:

Determine the required intake air volume of the engine according to the target torque;

The required opening degree of the nozzle ring is determined according to the current rotation speed and the required intake air volume.

Another object of the present disclosure is to provide a control device for a variable-section turbocharger, which is applied to a vehicle. The vehicle includes an engine with a variable-section turbocharger, and the variable-section turbocharger includes A nozzle ring, wherein the device includes:

An obtaining module, used to obtain the current speed and target torque of the engine;

The first determining module is configured to determine the current inflection point opening degree according to the current rotation speed; the current inflection point opening degree is for the current rotation speed and maximizes the boost pressure of the variable area turbocharger Value of nozzle ring opening;

A second determining module, configured to determine the required opening degree of the nozzle ring according to the current rotation speed and the target torque;

The third determining module is configured to determine the target opening of the nozzle ring according to the larger value of the current inflection point opening and the required opening;

The control module is used to adjust the opening degree of the nozzle ring to the target opening degree.

Optionally, in the control device, the control module includes:

The first obtaining unit is configured to obtain the current opening degree of the nozzle ring;

The first determining unit is configured to determine the driving duty ratio and driving direction for the nozzle ring according to the current opening degree and the target opening degree and through a proportional calculus closed-loop adjustment algorithm;

The first control unit is configured to adjust the opening degree of the nozzle ring to the larger value of the current inflection point opening degree and the required opening degree according to the driving duty ratio and the driving direction.

Optionally, in the control device, the adjusting the opening of the nozzle ring to the target opening includes:

The second acquiring unit is configured to acquire the current opening degree of the nozzle ring;

The second determining unit is configured to determine the target opening for the nozzle ring according to the current opening and the target opening and using a proportional calculus closed-loop adjustment algorithm when the current inflection point opening is less than the required opening The driving duty cycle and driving direction;

The second control unit is configured to adjust the opening degree of the nozzle ring to the target opening degree according to the driving duty ratio and the driving direction;

The third control unit is configured to adjust the opening degree of the nozzle ring to the target opening degree when the current inflection point opening degree is greater than or equal to the required opening degree.

Optionally, in the control device, the vehicle stores a corresponding relationship between the rotation speed of the engine and the opening degree of the inflection point, and the corresponding relationship indicates that the engine is at different rotation speeds, corresponding to the The opening degree of the nozzle ring at which the boost pressure of the variable section turbocharger reaches a maximum value; the first determining module is specifically configured to determine the current opening degree of the inflection point according to the current rotation speed and the corresponding relationship.

Optionally, in the control device, in the correspondence relationship, the rotation speed is divided into a plurality of rotation speed intervals according to a preset step length, and each of the rotation speed intervals corresponds to an opening degree of the inflection point.

Compared with the prior art, the control method and device of the variable cross-section turbocharger described in the present disclosure have the following advantages:

When the engine is running, first obtain the current speed and target torque of the engine; then, according to the current speed, determine the nozzle ring opening for the current speed and make the boost pressure of the variable area turbocharger reach a maximum value , Obtain the current inflection point opening; and determine the required opening of the nozzle ring according to the current speed and target torque, and then adjust the opening of the nozzle ring to the larger value of the current inflection point opening and the required opening . That is to say, the above-mentioned inflection point opening is regarded as the lower limit of the opening degree of the nozzle ring at the corresponding engine speed. When the torque demand of the engine changes, the larger value of the required opening degree and the current inflection point opening degree corresponding to the current vehicle speed is compared with the nozzle ring. The opening degree is adjusted so that the opening degree of the nozzle ring will not be lower than the current inflection point opening degree, which can also avoid the situation that the supercharger has a sudden increase in the pressure at the front end of the turbo and that the boost pressure cannot be established, thereby effectively protecting the supercharger And the engine can prolong its service life; in addition, because the above-mentioned control process does not require additional devices, that is, it will not increase the production cost of the engine.

Another object of the present disclosure is to provide a vehicle that includes an engine with a variable-section turbocharger, and the variable-section turbocharger includes a nozzle ring, wherein the vehicle further includes the Variable area turbocharger control device.

The vehicle has the same advantages as the above-mentioned variable-section turbocharger control method and device compared with the prior art, and will not be repeated here.

The present disclosure provides a computing processing device, including:

A memory in which computer-readable codes are stored;

One or more processors, and when the computer-readable code is executed by the one or more processors, the computing processing device executes the above-mentioned control method.

The present disclosure provides a computer program, including computer-readable code, which when the computer-readable code runs on a computing processing device, causes the computing processing device to execute the above-mentioned control method.

The present disclosure provides a computer-readable medium in which the above-mentioned computer program is stored.

The above description is only an overview of the technical solutions of the present disclosure. In order to understand the technical means of the present disclosure more clearly, they can be implemented in accordance with the content of the specification, and in order to make the above and other objectives, features and advantages of the present disclosure more obvious and easy to understand. In the following, specific embodiments of the present disclosure are specifically cited.

Brief description of the drawings

The drawings constituting a part of the present disclosure are used to provide a further understanding of the present disclosure. The exemplary embodiments and descriptions of the present disclosure are used to explain the present disclosure, and do not constitute an improper limitation of the present disclosure. For those of ordinary skill in the art, Without creative work, other drawings can be obtained based on these drawings. In the attached picture:

FIG. 1 is a schematic flow chart of a control method of a variable cross-section turbocharger proposed by an embodiment of the disclosure;

FIG. 2 is a schematic diagram of the boost pressure curve and the pressure curve of the front end of the turbine proposed in a preferred embodiment of the present disclosure;

3 is a schematic flow chart of a control method of a variable cross-section turbocharger proposed in a preferred embodiment of the present disclosure;

4 is an execution flow chart of the control method of the variable section turbocharger proposed by the embodiment of the disclosure;

FIG. 5 is a schematic structural diagram of a control device for a variable cross-section turbocharger proposed by an embodiment of the disclosure;

Fig. 6 schematically shows a block diagram of a computing processing device for executing the method according to the present disclosure; and

Fig. 7 schematically shows a storage unit for holding or carrying program codes for implementing the method according to the present disclosure.

A detailed description

Hereinafter, embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other if there is no conflict.

Hereinafter, the present disclosure will be described in detail with reference to the drawings and in conjunction with the embodiments.

Please refer to FIG. 1, which shows a schematic flowchart of a method for controlling a variable-section turbocharger provided by an embodiment of the present disclosure, which is applied to a vehicle, and the vehicle includes an engine with a variable-section turbocharger, The variable area turbocharger includes a nozzle ring, and the vehicle stores a correspondence relationship between a rotation speed of the engine and an opening degree of an inflection point, and the opening degree of the inflection point is for the rotation speed and makes the variable The supercharging pressure of the cross-section turbocharger reaches the maximum nozzle ring opening degree; the method includes steps S100-S400.

S100. Acquire the current speed and target torque of the engine.

In the above step S100, the current rotation speed refers to the rotation speed in the current state of the engine, and the target torque value mentioned above is the required torque that the driver hopes the engine can provide. Because the opening degree of the nozzle ring is directly related to the engine speed and torque demand, it is necessary to obtain the current engine speed and target torque in real time when the vehicle is running, so as to adjust and control the opening degree of the nozzle ring later. Among them, the current engine speed can be directly obtained by monitoring the engine speed; and the target torque is based on the preset corresponding relationship between the accelerator pedal angle and the torque, and the target torque of the engine can be obtained by obtaining the current accelerator pedal angle. The target torque directly corresponds to the working state of the engine; when the target torque is large, it means that the engine needs to enter a high-load working state; when the target torque is small, it means that the engine needs to enter a low-load working state. Therefore, if the target torque changes, it means that the driver's demand for the engine has changed. Accordingly, the nozzle ring of the turbocharger should be adjusted accordingly to output a torque that matches the target torque.

Step S200: Determine the current opening of the inflection point according to the current rotation speed; the current opening of the inflection point is the nozzle ring for the current rotation speed and the boost pressure of the variable section turbocharger reaches a maximum value Opening.

In the above step S200, the opening degree of the inflection point corresponding to the current rotation speed is determined according to the characteristics of the engine. The opening of the inflection point refers to the opening of the nozzle ring corresponding to the maximum value of the supercharging pressure of the variable-section turbocharger when the engine is in each speed state. That is, when the engine is maintained at various speeds and the opening of the nozzle ring is changed from large to small, the boost pressure of the variable-section turbocharger changes from increasing to decreasing. Opening of the nozzle ring. In each of the above-mentioned speed states, if the opening of the nozzle ring is smaller than the corresponding opening of the inflection point, the pressure at the front end of the turbocharger will rise sharply, causing the turbo-end boost pressure to fail to build up normally. That is to say, the above-mentioned inflection point opening is the minimum nozzle ring opening at which the variable-section turbocharger can be normally supercharged at the corresponding speed, and it is also to ensure that the supercharger and the engine will not be caused by excessive pressure at the front end of the turbocharger. The smallest opening that can cause damage.

Step S300: Determine the required opening degree of the nozzle ring according to the current rotation speed and the target torque.

In the above step S300, the above-mentioned required opening degree refers to the opening degree of the nozzle ring in order to enable the engine to provide the target torque at the current speed. Because the target torque that the engine needs to provide determines the required intake air volume, and the required intake air volume and the current engine speed can determine the boost pressure provided by the supercharger, and the boost pressure of the supercharger is It is achieved by adjusting the opening degree of the nozzle ring. Therefore, according to the current speed and the above-mentioned target torque, the required opening degree of the nozzle ring can be determined.

In practical applications, the above step S300 specifically determines the required intake air volume of the engine according to the above target torque, and then determines the required opening degree of the nozzle ring according to the above current speed and the above required air intake volume.

Step S400: Determine the target opening of the nozzle ring according to the larger value of the current inflection point opening and the required opening.

In the above step S400, the current inflection point opening determined in the above step S200 is compared with the required opening determined in the above step S300, and the larger value of the two is used as the final execution target opening of the nozzle ring.

Step S500: The opening degree of the nozzle ring is adjusted to the target opening degree.

Because the opening of the nozzle ring is adjusted according to the larger of the current opening of the inflection point and the required opening, the opening of the nozzle ring is always not lower than the current opening of the inflection point, which can also prevent the supercharger from appearing. A situation in which the pressure at the front end of the turbine rises sharply and the boost pressure cannot be established. Among them, it should be noted that when the aforementioned required opening is less than the aforementioned current inflection point opening, if the nozzle ring is adjusted to the aforementioned required opening, the pressure at the front end of the turbine will rise sharply and the boost pressure cannot be established. The boost pressure provided by the supercharger is actually less than the boost pressure provided by the supercharger when the nozzle ring is at the current inflection point opening, which also causes the pressure on the front end of the turbine to be too large and damage the supercharger.

Compared with the prior art, the control method of the variable cross-section turbocharger described in the present disclosure has the following advantages:

When the engine is running, first obtain the current speed and target torque of the engine; then, according to the current speed, determine the nozzle ring opening for the current speed and make the boost pressure of the variable area turbocharger reach a maximum value , Obtain the current inflection point opening; and determine the required opening of the nozzle ring according to the current speed and target torque, and then adjust the opening of the nozzle ring to the larger value of the current inflection point opening and the required opening . That is to say, the above-mentioned inflection point opening is regarded as the lower limit of the opening degree of the nozzle ring at the corresponding engine speed. When the torque demand of the engine changes, the larger value of the current inflection point opening corresponding to the required opening and the current vehicle speed is compared to the nozzle ring. Adjust the opening degree of the nozzle ring so that the opening degree of the nozzle ring will not be lower than the current inflection point opening degree, which can also avoid the situation that the turbocharger pressure rises rapidly at the front end of the turbo and the boost pressure cannot be established, thereby effectively protecting the boost pressure And engine to extend its service life.

Optionally, in one embodiment, in the control method according to the embodiment of the present disclosure, the vehicle stores a correspondence relationship between the rotation speed of the engine and the opening of the inflection point, and the correspondence relationship indicates that the engine is At different speeds, the corresponding nozzle ring openings that enable the supercharging pressure of the variable cross-section turbocharger to reach a maximum value; the step S200 specifically includes:

Step S201: Determine the current inflection point opening degree according to the current rotation speed and the corresponding relationship.

In this embodiment, taking into account the differences in the performance of each engine, it is necessary to first determine the opening of the inflection point corresponding to each rotation speed, and save each rotation speed and its corresponding inflection point opening in a one-to-one correspondence relationship, that is, the engine rotation speed can be obtained. Correspondence with the opening of the inflection point. Therefore, in the foregoing step S200, the current inflection point opening corresponding to the current rotation speed can be quickly inquired through the current rotation speed and the foregoing corresponding relationship.

In practical applications, the corresponding relationship between the above-mentioned rotation speed and the opening of the inflection point can be determined by bench experiments, as follows:

In the bench test, first set the nozzle ring opening to 100%, and then in each speed state in turn, while keeping the speed constant, first adjust the accelerator pedal opening to 100%, and the engine is at the basic boost pressure. And the nozzle ring is also fully open; then gradually lower the accelerator pedal opening, and the nozzle ring opening will also decrease until the nozzle ring opening drops to 0; continue to record the turbocharger position during the above process. Provided the supercharging pressure change and the pressure change of the front end of the turbine, the supercharging pressure curve and the pressure curve of the front end of the turbine can be obtained for different speeds. Please refer to Fig. 2 for details, which shows a schematic diagram of the supercharging pressure curve and the pressure curve of the front end of the turbine at the same speed. Among them, the abscissa is the opening degree of the nozzle ring, a represents the supercharging pressure curve, and b represents the pressure curve of the turbine front end.

As shown in Figure 2, as the opening of the nozzle ring decreases, the boost pressure and the pressure at the front end of the turbine gradually increase; when the opening of the nozzle ring decreases to a specific value M, the pressure in front of the vortex rises instantly, and the boost When the pressure starts to decrease gradually, the specific value M is determined as the inflection point opening corresponding to the rotation speed, and the specific value is recorded and filled in the inflection point opening map.

The above-mentioned inflection point opening degree diagram shows the corresponding relationship between the rotation speed and the inflection point opening degree. In the inflection point opening degree diagram, the abscissa is the rotation speed, and the ordinate is the inflection point opening degree.

It can be seen from Figure 2 that as long as the actual opening of the nozzle ring is greater than the value of M, there will be no problem of a sudden increase in pressure before the vortex, which can effectively protect the supercharger and the engine.

Optionally, in a specific embodiment, in the above-mentioned correspondence relationship, the above-mentioned rotational speed is divided into a plurality of rotational speed intervals according to a preset step length, and each of the above-mentioned rotational speed intervals corresponds to an opening degree of the inflection point.

In this embodiment, a certain rotation speed is set to correspond to a turning point opening. Considering that the opening of the nozzle ring continues to decrease from the turning point opening, the boost pressure provided by the supercharger does not drop to 0, so you can set an inflection point opening for the similar speed, that is, set an inflection point opening for a certain speed, which can avoid adjusting the inflection point opening too frequently when the engine is running, and at the same time, it can also greatly reduce the determination of the above in the actual experiment. For the workload of the corresponding relationship, it is not necessary to perform the above-mentioned bench test for each rotation speed, but to perform the above-mentioned bench test at a preset step interval. In practical applications, the aforementioned preset step length can be set to 400 revolutions.

Furthermore, considering that the opening of the inflection point is not sensitive to changes in speed at high speeds, the preset step length can be set to 200 when the speed is lower than the inflection point speed, and when the speed is higher than the inflection point speed. The preset step length of is 400, where the inflection point speed is the speed when the engine's external characteristic curve changes from a constant torque state to a constant power state.

Optionally, in a specific implementation manner, the foregoing step S500 includes steps S501 to S503:

Step S501: Obtain the current opening degree of the nozzle ring.

In the above step S501, the current opening degree of the nozzle ring is obtained, so that the opening degree of the nozzle ring can be adjusted to the above-mentioned target opening degree by the principle of proportional calculus closed-loop adjustment. Among them, the current opening degree of the nozzle ring can be obtained directly by monitoring the current state of the nozzle ring.

Step S502: Determine the driving duty ratio and driving direction of the nozzle ring according to the current opening degree and the target opening degree, and using a proportional calculus closed-loop adjustment algorithm.

In the above step S502, the driving direction is determined according to the difference between the current opening and the above target opening, and at the same time, the difference between the current opening and the target opening is input into the proportional calculus closed-loop adjustment algorithm. The integral closed-loop adjustment algorithm uses the proportional calculus closed-loop adjustment principle to calculate, and can calculate the driving duty ratio of the driving motor used to drive the adjustment of the nozzle ring opening. Specifically, the required target opening degree is used as a reference value, and the driving duty ratio is calculated through proportional calculus closed-loop adjustment according to the difference between the above-mentioned target opening degree and the current opening degree.

In practical applications, the above step S502 can be implemented by a proportional calculus controller.

Step S503: Adjust the opening degree of the nozzle ring to the target opening degree according to the driving duty ratio and the driving direction.

In the above step S503, using the driving duty ratio determined in step S502, that is, the driving direction, the driving motor is controlled to adjust the opening degree of the nozzle ring until the opening degree of the nozzle ring is adjusted to the above-mentioned target opening degree.

In this embodiment, the proportional-calculus closed-loop adjustment algorithm is used to perform real-time tracking adjustment to achieve precise control of the opening of the nozzle ring.

Optionally, in an implementation manner, the foregoing step S500 includes steps S511 to S514:

Step S511: Obtain the current opening degree of the nozzle ring.

For the above step S511, reference may be made to the detailed description of step S501, which will not be repeated here.

Step S512: When the current inflection point opening is less than the required opening, determine the driving duty for the nozzle ring according to the current opening and the target opening, and using a proportional calculus closed-loop adjustment algorithm Compared with the driving direction.

In the above step S512, that is, only when the current inflection point opening is less than the required opening, the proportional calculus closed-loop adjustment algorithm is introduced to determine the driving duty ratio and driving direction of the nozzle ring.

Step S513: Adjust the opening degree of the nozzle ring to the target opening degree according to the driving duty ratio and the driving direction.

For the above step S513, refer to the detailed description of step S503, which will not be repeated here.

Step S514: When the current inflection point opening is greater than or equal to the required opening, the opening of the nozzle ring is adjusted to the target opening.

In the above step S514, that is, when the current inflection point opening is greater than or equal to the required opening, the proportional calculus adjustment algorithm is not introduced to adjust the opening of the nozzle ring, but the opening of the nozzle ring is directly adjusted to the target The opening degree can ensure that during the adjustment process, the opening degree of the nozzle ring is always greater than or equal to the above-mentioned current inflection point opening degree, thereby preventing excessive intervention of proportional calculus correction and causing the actual opening degree of the nozzle ring to be less than the current inflection point opening degree. .

In this embodiment, when the demand opening degree is greater than the current inflection point opening degree, the proportional calculus adjustment algorithm is used to adjust the nozzle ring opening degree to the target opening degree; and when the demand opening degree is less than or equal to the current inflection point opening degree, no The proportional calculus adjustment algorithm is introduced to adjust the opening degree of the nozzle ring, but the opening degree of the nozzle ring is directly adjusted to the target opening degree. This embodiment can not only achieve precise control of the opening degree of the nozzle ring, but also can avoid the situation that the actual opening degree of the nozzle ring is smaller than the current opening degree of the inflection point due to excessive intervention of the proportional calculus algorithm correction.

Please refer to FIG. 3, which shows a schematic flow chart of a method for controlling a variable-section turbocharger according to a preferred embodiment of the present disclosure, which is applied to a vehicle, and the vehicle includes a variable-section turbocharger. An engine, the variable-section turbocharger includes a nozzle ring, and the vehicle stores a correspondence relationship between the rotation speed of the engine and the inflection point opening degree, and the correspondence relationship indicates that the engine corresponds to the engine at different rotation speeds. The opening of the nozzle ring that makes the supercharging pressure of the variable-section turbocharger reach a maximum value; The opening degree of the nozzle ring at which the pressure reaches the maximum value; the method includes steps S301 to S308.

Step S301: Obtain the current speed and target torque of the engine.

For the above step S301, reference may be made to the detailed description of step S100, which will not be repeated here.

Step S302: Determine the current inflection point opening degree according to the current rotation speed and the corresponding relationship.

For the foregoing step S302, reference may be made to the detailed description of step S201, which will not be repeated here.

Step S303: Determine the required opening degree of the nozzle ring according to the current rotation speed and the target torque.

For the foregoing step S303, reference may be made to the detailed description of step S300, which will not be repeated here.

Step S304: Determine the target opening of the nozzle ring according to the larger value of the current inflection point opening and the required opening.

Step S305: Obtain the current opening degree of the nozzle ring.

For the foregoing step S305, reference may be made to the detailed description of step S501, which will not be repeated here.

Step S306: When the required opening degree is greater than the current inflection point opening degree, according to the current opening degree and the target opening degree, and using a proportional calculus closed-loop adjustment algorithm, determine the driving duty for the nozzle ring Compared with the driving direction.

For the above step S306, reference may be made to the detailed description of step S502, which will not be repeated here.

Step S307: Adjust the opening degree of the nozzle ring to the target opening degree according to the driving duty ratio and the driving direction.

For the foregoing step S307, reference may be made to the detailed description of step S503, which will not be repeated here.

Step S308: When the required opening degree is less than or equal to the current inflection point opening degree, the opening degree of the nozzle ring is adjusted to the target opening degree.

For the foregoing step S308, reference may be made to the detailed description of step S514, which will not be repeated here.

Compared with the prior art, the control method of the variable cross-section turbocharger described in the embodiments of the present disclosure has the following advantages:

The above-mentioned inflection point opening is regarded as the lower limit of the opening of the nozzle ring at the corresponding engine speed. When the torque demand of the engine changes, the larger value of the required opening and the current inflection point opening corresponding to the current vehicle speed is used as the target opening. Adjust the opening of the nozzle ring; and when the required opening is greater than the current inflection point opening, directly adjust the opening of the nozzle ring to the target opening through a proportional calculus closed-loop adjustment algorithm; When the required opening degree is less than or equal to the current inflection point opening degree, the opening degree of the nozzle ring is directly adjusted to the target opening degree; through the above method, the accuracy of the opening degree of the nozzle ring cannot be achieved. Control to avoid the fact that the actual opening of the nozzle ring is less than the current opening of the inflection point due to the excessive intervention of the proportional calculus algorithm correction, which can also prevent the turbocharger from experiencing a sudden increase in the pressure at the front of the turbo and causing the boost pressure to be unable to build Circumstances, thereby effectively protecting the supercharger and engine and extending its service life.

In practical applications, please refer to FIG. 4, which shows an execution flow chart of the control method of the variable cross-section turbocharger proposed by the embodiment of the present disclosure.

As shown in Fig. 4, in step S41, the engine's required air volume is determined by the current engine speed and required torque, and then in step S42, the required air volume is used to determine the nozzle ring required opening; at the same time, in step S43, the aforementioned Determine the opening of the inflection point of the nozzle ring quickly, and use the opening of the inflection point as the minimum opening of the nozzle ring; then in steps S45 and S46, the larger of the minimum opening and the required opening is used as the target opening of the nozzle ring In step S47, when the required opening is greater than the minimum opening, the proportional calculus adjustment mechanism (PID) of the VGT is triggered; in step S48, if the proportional calculus adjustment mechanism is triggered, the proportional calculus adjustment mechanism is triggered , The actual opening of the nozzle ring is controlled until the opening of the nozzle ring is adjusted to the target opening; in step S48, if the proportional calculus adjustment mechanism is not triggered, the opening of the nozzle ring is adjusted to the target opening Spend.

Another object of the present disclosure is to provide a control device for a variable-section turbocharger, which is applied to a vehicle. The vehicle includes an engine with a variable-section turbocharger, and the variable-section turbocharger includes Nozzle ring, please refer to FIG. 5, which shows a schematic structural diagram of a control device for a variable cross-section turbocharger proposed in an embodiment of the present disclosure, and the device includes:

The obtaining module 10 is used to obtain the current speed and target torque of the engine;

The first determining module 20 is configured to determine the current opening of the inflection point according to the current speed; the current opening of the inflection point is for the current speed and makes the supercharging pressure of the variable area turbocharger reach the extreme Large-value nozzle ring opening;

The second determining module 30 is configured to determine the required opening degree of the nozzle ring according to the current speed and the target torque;

The third determining module 40 is configured to determine the target opening degree of the nozzle ring according to the larger value of the current inflection point opening degree and the required opening degree;

The control module 50 is configured to adjust the opening degree of the nozzle ring to the target opening degree.

In the system according to the embodiment of the present disclosure, when the engine is running, the acquisition module 10 first acquires the current engine speed and target torque; then the first determination module 20 determines the current engine speed and target torque according to the current engine speed. The boost pressure of the variable area turbocharger reaches the maximum current inflection point opening; and the second determining module 30 determines the required opening of the nozzle ring according to the current speed and target torque, and then the control module 50 determines the opening of the nozzle ring. The opening degree of the nozzle ring is adjusted to the larger value of the current inflection point opening degree and the required opening degree. That is to say, the above-mentioned inflection point opening is regarded as the lower limit of the opening degree of the nozzle ring at the corresponding engine speed. When the torque demand of the engine changes, the larger value of the required opening degree and the current inflection point opening degree corresponding to the current vehicle speed is compared with the nozzle ring. The opening degree is adjusted so that the opening degree of the nozzle ring will not be lower than the current inflection point opening degree, which can also avoid the situation that the supercharger has a sudden increase in the pressure at the front end of the turbo and that the boost pressure cannot be established, thereby effectively protecting the supercharger And engine to extend its service life.

Optionally, in the control device, the control module 50 includes:

A second acquiring unit, configured to acquire the current opening degree of the nozzle ring when the current inflection point opening degree is less than the required opening degree;

The second determining unit is configured to determine the driving duty ratio and driving direction of the nozzle ring according to the current opening degree and the target opening degree and using a proportional calculus closed-loop adjustment algorithm;

Optionally, in the control device, the vehicle stores a corresponding relationship between the rotation speed of the engine and the opening degree of the inflection point, and the corresponding relationship indicates that the engine is at different rotation speeds, corresponding to the The opening of the nozzle ring at which the boost pressure of the variable section turbocharger reaches a maximum value; the first determining module 20 is specifically configured to determine the current opening of the inflection point according to the current rotation speed and the corresponding relationship.

The vehicle has the same advantages as the above-mentioned variable-section turbocharger control method and device compared to the prior art, and will not be repeated here.

The technical details and benefits of the above-mentioned system and vehicle have been described in detail in the above-mentioned method, and will not be repeated here.

In summary, the control method, device, and vehicle of the variable-section turbocharger provided by the present disclosure first obtain the current engine speed and target torque when the engine is running; And the nozzle ring opening that makes the supercharging pressure of the variable cross-section turbocharger reach the maximum value to obtain the current inflection point opening; and the required opening of the nozzle ring is determined according to the current speed and the target torque, and then the The larger value of the current inflection point opening and the required opening is used as the target opening, and the opening of the nozzle ring is adjusted according to the target opening. That is to say, the above-mentioned inflection point opening is regarded as the lower limit of the opening degree of the nozzle ring at the corresponding engine speed. When the torque demand of the engine changes, the larger value of the required opening degree and the current inflection point opening degree corresponding to the current vehicle speed is compared with the nozzle ring. The opening degree is adjusted so that the opening degree of the nozzle ring will not be lower than the current inflection point opening degree, which can also avoid the situation that the supercharger has a sudden increase in the pressure at the front end of the turbo and that the boost pressure cannot be established, thereby effectively protecting the supercharger And the engine can prolong its service life; in addition, because the above-mentioned control process does not require additional devices, that is, it will not increase the production cost of the engine.

Those skilled in the art can clearly understand that, for the convenience and conciseness of description, the specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in One place, or it can be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the objectives of the solutions of the embodiments. Those of ordinary skill in the art can understand and implement it without creative work.

The various component embodiments of the present disclosure may be implemented by hardware, or by software modules running on one or more processors, or by a combination of them. Those skilled in the art should understand that a microprocessor or a digital signal processor (DSP) may be used in practice to implement some or all of the functions of some or all of the components in the computing processing device according to the embodiments of the present disclosure. The present disclosure can also be implemented as a device or device program (for example, a computer program and a computer program product) for executing part or all of the methods described herein. Such a program for realizing the present disclosure may be stored on a computer-readable medium, or may have the form of one or more signals. Such a signal can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

For example, FIG. 6 shows a computing processing device that can implement the method according to the present disclosure. The computing processing device traditionally includes a processor 1010 and a computer program product in the form of a memory 1020 or a computer readable medium. The memory 1020 may be an electronic memory such as flash memory, EEPROM (Electrically Erasable Programmable Read Only Memory), EPROM, hard disk, or ROM. The memory 1020 has a storage space 1030 for executing program codes 1031 of any method steps in the above methods. For example, the storage space 1030 for program codes may include various program codes 1031 respectively used to implement various steps in the above method. These program codes can be read from or written into one or more computer program products. These computer program products include program code carriers such as hard disks, compact disks (CDs), memory cards, or floppy disks. Such a computer program product is usually a portable or fixed storage unit as described with reference to FIG. 7. The storage unit may have storage segments, storage spaces, etc., arranged similarly to the memory 1020 in the computing processing device of FIG. 6. The program code can be compressed in an appropriate form, for example. Generally, the storage unit includes computer-readable codes 1031', that is, codes that can be read by, for example, a processor such as 1010. These codes, when run by a computing processing device, cause the computing processing device to execute the method described above. The various steps.

In the claims, any reference signs placed between parentheses should not be constructed as a limitation to the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of multiple such elements. The present disclosure can be realized by means of hardware including several different elements and by means of a suitably programmed computer. In the unit claims listing several devices, several of these devices may be embodied in the same hardware item. The use of the words first, second, and third, etc. do not indicate any order. These words can be interpreted as names.

The above descriptions are only preferred embodiments of the present disclosure, and are not intended to limit the present disclosure. Any modification, equivalent replacement and improvement made within the spirit and principle of the present disclosure shall be included in the protection of the present disclosure. Within range.

The above are only specific implementations of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present disclosure. It should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

A method for controlling a variable-section turbocharger is applied to a vehicle, the vehicle includes an engine with a variable-section turbocharger, the variable-section turbocharger includes a nozzle ring, and is characterized in that: The methods include:

Acquiring the current speed and target torque of the engine;

Determine the current opening of the inflection point according to the current rotation speed; the current opening of the inflection point is the opening of the nozzle ring for the current rotation speed and the boost pressure of the variable area turbocharger reaches a maximum value;

Determine the required opening degree of the nozzle ring according to the current speed and the target torque;

Determining the target opening of the nozzle ring according to the larger value of the current inflection point opening and the required opening;

The opening degree of the nozzle ring is adjusted to the target opening degree.
The control method according to claim 1, wherein the adjusting the opening degree of the nozzle ring to the target opening degree comprises:

Acquiring the current opening degree of the nozzle ring;

Determine the driving duty cycle and driving direction of the nozzle ring according to the current opening degree and the target opening degree, and through a proportional calculus closed-loop adjustment algorithm;

According to the driving duty ratio and the driving direction, the opening degree of the nozzle ring is adjusted to a larger value of the current inflection point opening degree and the required opening degree.
The control method according to claim 1, wherein the adjusting the opening degree of the nozzle ring to the target opening degree comprises:

Acquiring the current opening degree of the nozzle ring;

When the current inflection point opening is less than the required opening, according to the current opening and the target opening, and through the proportional calculus closed-loop adjustment algorithm, the driving duty cycle and driving of the nozzle ring are determined direction;

Adjusting the opening degree of the nozzle ring to the target opening degree according to the driving duty ratio and the driving direction;

When the current inflection point opening is greater than or equal to the required opening, the opening of the nozzle ring is adjusted to the target opening.
The control method according to claim 1, wherein the vehicle stores a correspondence relationship between the rotation speed of the engine and the inflection point opening, and the correspondence relationship indicates that the corresponding relationship between the engine speed and the inflection point opening is The opening degree of the nozzle ring that enables the supercharging pressure of the variable-section turbocharger to reach a maximum value; the determining the current opening degree of the inflection point according to the current rotation speed includes:

Determine the current inflection point opening degree according to the current rotation speed and the corresponding relationship.
The control method according to claim 4, wherein, in the correspondence relationship, the rotation speed is divided into a plurality of rotation speed intervals according to a preset step length, and each of the rotation speed intervals corresponds to an opening degree of the inflection point.
The control method according to claim 5, characterized in that the rotation speed when the external characteristic curve of the engine is changed from the constant torque state to the constant power state is taken as the inflection point rotation speed;

When the rotation speed is lower than the inflection point rotation speed, the preset step length is set to 200 revolutions;

When the rotation speed is higher than the inflection point rotation speed, the preset step length is set to 400 revolutions.
The control method according to claim 1, wherein the determining the required opening degree of the nozzle ring according to the current rotation speed and the target torque comprises:

Determine the required intake air volume of the engine according to the target torque;

The required opening degree of the nozzle ring is determined according to the current rotation speed and the required intake air volume.
A control device for a variable section turbocharger is applied to a vehicle. The vehicle includes an engine with a variable section turbocharger, the variable section turbocharger includes a nozzle ring, and is characterized in that: The device includes:

An obtaining module, used to obtain the current speed and target torque of the engine;

The first determining module is configured to determine the current inflection point opening degree according to the current rotation speed; the current inflection point opening degree is for the current rotation speed and maximizes the boost pressure of the variable area turbocharger Value of nozzle ring opening;

A second determining module, configured to determine the required opening degree of the nozzle ring according to the current rotation speed and the target torque;

The third determining module is configured to determine the target opening of the nozzle ring according to the larger value of the current inflection point opening and the required opening;

The control module is used to adjust the opening degree of the nozzle ring to the target opening degree.
The control device according to claim 8, wherein the control module comprises:

The first obtaining unit is configured to obtain the current opening degree of the nozzle ring;

The first determining unit is configured to determine the driving duty ratio and driving direction for the nozzle ring according to the current opening degree and the target opening degree and through a proportional calculus closed-loop adjustment algorithm;

The first control unit is configured to adjust the opening degree of the nozzle ring to the larger value of the current inflection point opening degree and the required opening degree according to the driving duty ratio and the driving direction.
The control device according to claim 8, wherein the control module comprises:

A second acquiring unit, configured to acquire the current opening degree of the nozzle ring when the current inflection point opening degree is less than the required opening degree;

The second determining unit is configured to determine the driving duty ratio and driving direction of the nozzle ring according to the current opening degree and the target opening degree and using a proportional calculus closed-loop adjustment algorithm;

The second control unit is configured to adjust the opening degree of the nozzle ring to the target opening degree according to the driving duty ratio and the driving direction;

The third control unit is configured to adjust the opening degree of the nozzle ring to the target opening degree when the current inflection point opening degree is greater than or equal to the required opening degree.
The control device according to claim 8, wherein the vehicle stores a corresponding relationship between the rotation speed of the engine and the opening of the inflection point, and the corresponding relationship indicates that the corresponding relationship between the engine speed and the inflection point opening is The opening of the nozzle ring that enables the supercharging pressure of the variable-section turbocharger to reach a maximum value;

The first determining module is specifically configured to determine the current inflection point opening degree according to the current rotation speed and the corresponding relationship.
The control device according to claim 11, wherein, in the correspondence relationship, the rotation speed is divided into a plurality of rotation speed intervals according to a preset step length, and each of the rotation speed intervals corresponds to an opening degree of the inflection point.
A vehicle, characterized in that the vehicle includes an engine with a variable-section turbocharger, and the variable-section turbocharger includes a nozzle ring, wherein the vehicle further includes any of claims 8-12. A control device for a variable cross-section turbocharger described in one item.
A computing processing device, characterized in that it comprises:

A memory in which computer-readable codes are stored;

One or more processors, and when the computer-readable code is executed by the one or more processors, the computing processing device executes the control method according to any one of claims 1-7.
A computer program comprising computer readable code, when the computer readable code runs on a computing processing device, causes the computing processing device to execute the control method according to any one of claims 1-7.
A computer readable medium in which the computer program according to claim 15 is stored.