阅读说明：本技术 失火缸确定方法、装置、设备及计算机可读存储介质 (Method, device and equipment for determining ignition loss cylinder and computer readable storage medium ) 是由 谭治学 梁健星 解同鹏 杨新达 潘永传 于 2019-09-27 设计创作，主要内容包括：本公开提供一种失火缸确定方法、装置、设备及计算机可读存储介质,包括确定发动机的失火模式；获取发动机运行时曲轴的速度信号,并根据发动机运行时目标气缸中的活塞的运动位置,在速度信号中获取目标气缸对应的第一速度、第二速度；根据失火模式、各个目标气缸对应的第一速度、第二速度,在目标气缸中确定失火缸。气缸失火后,其做功时推动曲轴旋转产生的速度会发生改变,因此,本公开提供的方法、装置、设备及计算机可读存储介质,根据气缸推动曲轴产生的速度信号,在各个目标缸中确定失火缸,更加准确、快速。(The present disclosure provides a misfire cylinder determination method, apparatus, device and computer readable storage medium comprising determining a misfire pattern of an engine; acquiring a speed signal of a crankshaft when the engine runs, and acquiring a first speed and a second speed corresponding to a target cylinder from the speed signal according to the movement position of a piston in the target cylinder when the engine runs; and determining a misfiring cylinder in the target cylinders according to the misfire pattern and the first speed and the second speed corresponding to each target cylinder. After the cylinder catches fire, the speed generated by pushing the crankshaft to rotate when the cylinder does work is changed, so that the method, the device, the equipment and the computer readable storage medium provided by the disclosure can determine the ignition cylinder in each target cylinder more accurately and quickly according to the speed signal generated by pushing the crankshaft by the cylinder.)

1. A misfire cylinder determination method comprising:

determining a misfire pattern of the engine;

acquiring a speed signal of a crankshaft when an engine runs, and acquiring a first speed and a second speed corresponding to a target cylinder in the speed signal according to the movement position of a piston in the target cylinder when the engine runs;

and determining a misfiring cylinder in the target cylinders according to the misfiring mode, the first speed and the second speed corresponding to each target cylinder.

2. The method of claim 1, wherein said obtaining a speed signal of a crankshaft while an engine is running comprises:

and acquiring the speed signal according to a gear ring speed measuring mechanism arranged at the flywheel end of the crankshaft.

3. The method of claim 1, wherein if the misfire pattern comprises any of:

single cylinder fire, symmetric cylinder fire, adjacent cylinder fire;

the obtaining, from the speed signal, a first speed and a second speed corresponding to a target cylinder according to a moving position of a piston in the target cylinder when the engine is running includes:

determining, in the speed signal, a first speed of the crankshaft when the crankshaft rotates a preset angle after a piston in the target cylinder moves to a top dead center;

in the speed signal, a second speed of the crankshaft is determined when a piston in the target cylinder moves to top dead center.

4. The method of claim 1, wherein if the misfire pattern comprises any of:

single cylinder fire, symmetric cylinder fire, adjacent cylinder fire;

the first speed comprises a first sub-speed, a second sub-speed; the second speed comprises a third sub-speed and a fourth sub-speed;

the acquiring a first speed and a second speed corresponding to a target cylinder from the speed signal according to the movement position of a piston in the target cylinder when the engine runs comprises the following steps:

determining, in the speed signal, a first sub-speed of the crankshaft when the crankshaft rotates by a first preset angle after the piston in the target cylinder moves to a top dead center, and a second sub-speed of the crankshaft when the crankshaft rotates by a second preset angle;

in the speed signal, a third sub-speed of the crankshaft when the piston in the target cylinder moves to top dead center, and a fourth sub-speed of the crankshaft when the crankshaft rotates a fourth preset angle are determined.

5. The method according to claim 4, wherein the first predetermined angle and the second predetermined angle differ by an angle value between two adjacent gears of the flywheel.

6. The method according to claim 4, wherein the fourth predetermined angle is an angle value between two adjacent gears of the flywheel.

7. A method according to any of claims 4-6, characterized in that if the misfire pattern comprises any of the following patterns:

single cylinder fire, symmetric cylinder fire, adjacent cylinder fire;

determining a misfiring cylinder in the target cylinders according to the misfiring mode and the first speed and the second speed corresponding to each target cylinder, including:

determining a misfire index corresponding to the target cylinder according to the first sub-speed, the second sub-speed, the third sub-speed and the fourth sub-speed;

and determining the misfiring cylinder in the target cylinder according to the misfire pattern and the misfire index of each target cylinder.

8. The method as claimed in claim 7, wherein the determining the misfiring cylinder in the target cylinders according to the misfire pattern and the misfire index of each of the target cylinders comprises:

if the misfire mode is single-cylinder misfire, determining the target cylinder with the minimum misfire index as a misfire cylinder;

and or if the misfire pattern is symmetrical cylinder misfire, determining two symmetrical cylinders with the smallest sum of the misfire indexes as misfiring cylinders;

and or if the misfire pattern is that the adjacent cylinders misfire, determining two adjacent cylinders with the smallest sum of the misfire indexes as the misfiring cylinders.

9. The method of claim 1, wherein if the misfire pattern is a cylinder-by-cylinder misfire;

the obtaining, from the speed signal, a first speed and a second speed corresponding to a target cylinder according to a moving position of a piston in the target cylinder when the engine is running includes:

determining a plurality of first speeds of the crankshaft in the process that the piston of the next cylinder of the target cylinder moves to the top dead center when the crankshaft rotates by a first preset angle after the piston in the target cylinder moves to the top dead center in the speed signal;

and determining a plurality of corresponding second speeds according to the plurality of first speeds.

10. The method of claim 9, wherein said determining a corresponding plurality of second speeds from a plurality of said first speeds comprises:

determining an auxiliary line according to a fifth sub-speed of the crankshaft when the crankshaft rotates by a first preset angle after the piston in the target cylinder moves to a top dead center and a sixth sub-speed of the crankshaft when the piston of a next cylinder of the target cylinder moves to the top dead center;

and determining a plurality of second speeds corresponding to each first speed according to the auxiliary line and the plurality of first speeds.

11. The method as claimed in claim 9, wherein if the misfire pattern is one-cylinder-interval misfire, the determining of the misfiring cylinder among the target cylinders according to the misfire pattern, the first speed and the second speed corresponding to each target cylinder comprises:

determining a misfire index corresponding to the target cylinder according to the first speed and the second speed;

and determining the misfiring cylinder in the target cylinder according to the misfiring index of each target cylinder.

12. The method as claimed in claim 11, wherein the determining the misfiring cylinder in the target cylinders according to the misfire pattern and the misfire index of each of the target cylinders comprises:

and determining the two target cylinders which are separated by one cylinder and have the smallest sum of the misfire indexes.

13. The method of any of claims 1-6, 8-12, further comprising, after obtaining the speed signal of the crankshaft while the engine is running:

and removing the noise signal in the speed signal.

14. The method of any of claims 1-6, 8-12, further comprising, after obtaining the speed signal of the crankshaft while the engine is running:

and determining acceleration according to the speed signal, and removing a trend component in the speed signal according to the acceleration.

15. A misfire cylinder determining apparatus characterized by comprising:

a mode determination module to determine a misfire mode of an engine;

the speed determination module is used for acquiring a speed signal of a crankshaft when an engine runs, and acquiring a first speed and a second speed corresponding to a target cylinder in the speed signal according to the motion position of a piston in the target cylinder when the engine runs;

and the ignition cylinder determining module is used for determining an ignition cylinder in the target cylinders according to the misfire pattern, the first speed and the second speed corresponding to each target cylinder.

16. A misfire cylinder determining apparatus, characterized by comprising:

a memory;

a processor; and

a computer program;

wherein the computer program is stored in the memory and configured to be executed by the processor to implement the method of any of claims 1-14.

17. A computer-readable storage medium, having stored thereon a computer program,

the computer program is executed by a processor to implement the method of any one of claims 1 to 14.

Technical Field

The present disclosure relates to engine technology, and more particularly, to a misfire cylinder determination method, apparatus, device, and computer readable storage medium.

Background

The engine is provided with a cylinder, which refers to a cylindrical metal work that is guided by the cylinder to perform linear reciprocating motion inside the cylinder by a piston, so that air converts thermal energy into mechanical energy through expansion in the engine cylinder.

When the engine is running, the mixture in the cylinder may not ignite, which is called misfire. The isolated fire in a short time can cause high emission of harmful gas and pollute the atmosphere; intermittent long-term misfires cause unburned air-fuel mixtures to burn in the catalyst and cause catalyst damage. Therefore, it is very necessary to determine the misfiring cylinder of the engine and process it.

Disclosure of Invention

The present disclosure provides a misfire cylinder determination method, apparatus, device and computer readable storage medium to solve the problem of inaccurate scheme for determining a misfire cylinder in the prior art.

A first aspect of the present disclosure is to provide a misfire cylinder determination method comprising:

determining a misfire pattern of the engine;

acquiring a speed signal of a crankshaft when an engine runs, and acquiring a first speed and a second speed corresponding to a target cylinder in the speed signal according to the movement position of a piston in the target cylinder when the engine runs;

and determining a misfiring cylinder in the target cylinders according to the misfiring mode, the first speed and the second speed corresponding to each target cylinder.

Another aspect of the present disclosure is to provide a misfire cylinder determining apparatus comprising:

a mode determination module to determine a misfire mode of an engine;

the speed determination module is used for acquiring a speed signal of a crankshaft when an engine runs, and acquiring a first speed and a second speed corresponding to a target cylinder in the speed signal according to the motion position of a piston in the target cylinder when the engine runs;

and the ignition cylinder determining module is used for determining an ignition cylinder in the target cylinders according to the misfire pattern, the first speed and the second speed corresponding to each target cylinder.

It is still another aspect of the present disclosure to provide a misfire cylinder determining apparatus comprising:

a memory;

a processor; and

a computer program;

wherein the computer program is stored in the memory and configured to be executed by the processor to implement the misfire cylinder determination method as described in the above first aspect.

Yet another aspect of the present disclosure is to provide a computer readable storage medium having stored thereon a computer program to be executed by a processor to implement the misfiring cylinder determining method as described in the above first aspect.

The misfire cylinder determining method, the device, the equipment and the computer readable storage medium provided by the disclosure have the technical effects that:

the present disclosure provides a misfire cylinder determination method, apparatus, device and computer readable storage medium comprising determining a misfire pattern of an engine; acquiring a speed signal of a crankshaft when the engine runs, and acquiring a first speed and a second speed corresponding to a target cylinder from the speed signal according to the movement position of a piston in the target cylinder when the engine runs; and determining a misfiring cylinder in the target cylinders according to the misfire pattern and the first speed and the second speed corresponding to each target cylinder. After the cylinder catches fire, the speed generated by pushing the crankshaft to rotate when the cylinder does work is changed, so that the method, the device, the equipment and the computer readable storage medium provided by the disclosure can determine the ignition cylinder in each target cylinder more accurately and quickly according to the speed signal generated by pushing the crankshaft by the cylinder.

Drawings

FIG. 1 is a schematic illustration of an engine according to an exemplary embodiment of the present invention;

FIG. 2 is a flowchart illustrating a misfire cylinder determination method in accordance with an exemplary embodiment of the present disclosure;

FIG. 3 is a flowchart illustrating a misfire cylinder determination method in accordance with a second exemplary embodiment of the present invention;

FIG. 4 is a flowchart illustrating a misfire cylinder determination method in accordance with a third exemplary embodiment of the present invention;

FIG. 5 is a flowchart illustrating a misfire cylinder determination method in accordance with a fourth exemplary embodiment of the present invention;

FIG. 6 is a schematic diagram of an auxiliary line according to an exemplary embodiment of the present invention;

FIGS. 7A and 7B are schematic views illustrating misfire indexes, respectively, for exemplary embodiments of the present invention;

fig. 8 is a block diagram showing a misfire cylinder determining apparatus in accordance with an exemplary embodiment of the present invention;

fig. 9 is a block diagram illustrating a misfire cylinder determining apparatus in accordance with another exemplary embodiment of the present invention;

fig. 10 is a block diagram illustrating a misfire cylinder determining apparatus according to an exemplary embodiment of the present invention.

Detailed Description

The engine is an important part of the automobile, and the automobile is driven to run by the engine. In the engine, a cylinder is provided, through which four strokes of the engine are realized, namely: an intake stroke, a compression stroke, a power stroke, and an exhaust stroke.

Once a cylinder fire happens, high emission of harmful gas can be caused, and the atmosphere is polluted; or the unburned mixture is burned in the catalyst and causes damage to the catalyst. Thus, when a misfire condition is found, it should be possible to quickly locate the misfiring cylinder so that it can be dealt with, for example, by shutting off the fuel supply to the misfiring cylinder.

The method provided by the embodiment is exemplified by an inline 6-cylinder engine.

FIG. 1 is a schematic illustration of an engine according to an exemplary embodiment of the present invention.

As shown in fig. 1, the engine is provided with 6 cylinders 11, and the 6 cylinders are arranged in a row. The 6 cylinders are mutually matched, so that stable power output is realized. The piston in the cylinder is connected with the crankshaft, and the piston can drive the crankshaft to rotate when moving, so that power is output.

Fig. 2 is a flowchart illustrating a misfire cylinder determination method according to an exemplary embodiment of the present invention.

As shown in fig. 2, the misfire cylinder determination method provided by the present embodiment includes:

in step 201, a misfire pattern of the engine is determined.

The method provided by the embodiment can be applied to a vehicle-mounted computer in a vehicle, and the vehicle-mounted computer determines the ignition cylinder according to the rotating speed output by the engine.

Wherein during operation of an engine of a vehicle, it may be monitored whether a misfire condition exists with the engine. For example, the speed fluctuations may be analyzed by a crankshaft position sensor to determine whether a misfire condition exists. It is also possible to determine whether a misfire condition exists by detecting the gas pressure in the cylinder.

Specifically, when the engine works normally, the crankshaft has acceleration and deceleration processes due to the compression and work-applying strokes. And the misfire can cause the misfire cylinder to work abnormally, so that the engine has one less due acceleration process, and therefore, the rotation speed fluctuation can be analyzed through the crankshaft position sensor, and the misfire condition is determined.

Further, a specific misfire pattern may also be determined when a misfire condition exists in the engine. For an inline six cylinder engine, misfire patterns that may occur include: single cylinder fire, symmetric cylinder fire, alternate cylinder fire, adjacent cylinder fire, etc.

In actual application, a filter algorithm corresponding to each misfire pattern may be set, and the output speed of the engine is filtered through each filter algorithm, so as to determine the final misfire pattern.

Wherein step 202 may be performed after determining that a misfire condition exists in the engine or after determining the misfire pattern.

In step 202, a speed signal of a crankshaft is obtained while an engine is running.

Specifically, when a cylinder in the engine works, a piston arranged in the cylinder moves to push a crankshaft to rotate, and then power is output. As the crankshaft rotates, a speed signal generated by its rotation may be collected.

Furthermore, a flywheel is arranged on the crankshaft, and the flywheel and the crankshaft rotate synchronously. Therefore, a speed measuring gear ring can be arranged on the flywheel, and the speed signal of the crankshaft can be determined by measuring the speed signal of the flywheel.

In practical application, a sensor can be arranged, the sensor is used for detecting the time difference of each tooth on the flywheel passing through the sensor, the rotation speed of the flywheel is further determined according to the time difference, and then the speed signal of the flywheel at each moment is obtained.

Alternatively, the speed signal of the engine output during one duty cycle may be obtained. One working cycle refers to a process that each cylinder in the engine completes one power output, and for an in-line six-cylinder engine, 6 cylinders complete one process of an air inlet stroke, a compression stroke, a power stroke and an exhaust stroke, and the process can be one working cycle.

Optionally, denoising processing may be performed on the speed signal, so that the speed signal is more accurate. Specifically, the engine can be calibrated in advance, the back-dragging signal of the engine can be determined, and the back-dragging signal can be removed from the acquired speed signal, so that the denoised speed signal can be obtained. The following steps can be processed based on the denoised speed signal, and the misfiring cylinder can be identified more accurately according to the speed of the crankshaft.

And step 203, acquiring a first speed and a second speed corresponding to the target cylinder from the speed signal according to the motion position of the piston in the target cylinder when the engine runs.

If the cylinder catches fire, the speed signal of the crankshaft has certain characteristics when the cylinder pushes the crankshaft to rotate. Therefore, the method provided by the embodiment can acquire the first speed and the second speed corresponding to the target cylinder from the speed signal according to the movement position of the piston in the target cylinder when the engine runs.

Specifically, the first speed and the second speed extracted in different misfire patterns may be different. For example, when the misfire pattern is single cylinder misfire, symmetric cylinder misfire, adjacent cylinder misfire, a first speed may be taken where each cylinder pushes the crankshaft at the fastest rotational speed, and a second speed that is the slowest.

Further, if the misfire pattern is every other cylinder, the rotating speed of the crankshaft can be collected in the process that the rotating speed of the crankshaft pushed by the current cylinder is the fastest and the rotating speed of the crankshaft pushed by the next cylinder is the slowest. The rotating speed of the flywheel within a period of time can be acquired through the sensor, and a speed signal is obtained. And determining a second speed according to the first speed in the period of time.

In actual use, the first speed and the second speed are speeds generated when the target cylinder pushes the crankshaft, and therefore, whether the target cylinder misfires can be analyzed based on these speeds.

And step 204, determining a misfiring cylinder in the target cylinders according to the misfire pattern and the first speed and the second speed corresponding to each target cylinder.

The misfire index of the target cylinder can be determined according to the first speed and the second speed of the target cylinder. For each cylinder, a corresponding misfire index may be determined, and a misfiring cylinder may be determined according to the misfire index and the misfire pattern of each cylinder.

Specifically, the misfire index may be an index related to a rotational speed of the crankshaft for measuring the rotation of the crankshaft by the target cylinder. If the target cylinder is on fire, the crankshaft rotation speed should be small when the target cylinder pushes the crankshaft to rotate. Therefore, the misfiring cylinder can be determined based on the index. For example, when the misfire pattern is a single cylinder misfire, the cylinder with the smallest index may be determined as the misfire cylinder.

The method provided by the present embodiment is used for determining a misfiring cylinder, and is performed by an apparatus provided with the method provided by the present embodiment, which is generally implemented in hardware and/or software.

The misfire cylinder determination method provided by the embodiment includes determining a misfire pattern of an engine; acquiring a speed signal of a crankshaft when the engine runs, and acquiring a first speed and a second speed corresponding to a target cylinder from the speed signal according to the movement position of a piston in the target cylinder when the engine runs; and determining a misfiring cylinder in the target cylinders according to the misfire pattern and the first speed and the second speed corresponding to each target cylinder. After the cylinder catches fire, the speed generated by pushing the crankshaft to rotate when the cylinder does work can be changed, so that the method provided by the embodiment determines the misfiring cylinder in each target cylinder more accurately and quickly according to the speed signal generated by pushing the crankshaft by the cylinder.

Fig. 3 is a flowchart illustrating a misfire cylinder determination method in accordance with a second exemplary embodiment of the present invention.

As shown in fig. 3, the misfire cylinder determination method provided by the present embodiment includes:

in step 301, a misfire pattern of the engine is determined.

The specific principle and implementation of step 301 are similar to those of step 201, and are not described herein again.

And step 302, acquiring a speed signal according to a gear ring speed measuring mechanism arranged at the flywheel end of the crankshaft.

In the method provided by this embodiment, a speed measuring mechanism for the gear ring may be provided at the flywheel end of the crankshaft. When each gear ring on the wheel passes through the mechanism, the mechanism outputs a corresponding signal, the signals can be sent to a vehicle-mounted computer, and the vehicle speed can be calculated after the vehicle-mounted computer performs filtering and other processing on the signals, so that a speed signal is obtained. For example, if the flywheel has 60 teeth, one revolution of the flywheel will produce sixty speed signals.

Specifically, after a signal is detected by the gear ring speed measuring mechanism, the signal is sent to the vehicle-mounted computer.

If the determined misfire pattern is any one of a single cylinder misfire, a symmetric cylinder misfire, an adjacent cylinder misfire, the steps of steps 303 or 304 may be performed.

Step 303, determining a first speed of the crankshaft when the crankshaft rotates a preset angle after the piston in the target cylinder moves to the top dead center in the speed signal.

In the speed signal, a second speed of the crankshaft at which the piston in the target cylinder moves to top dead center is determined, step 304.

If the misfire pattern determined in step 301 is any one of a single cylinder misfire, a symmetric cylinder misfire, and an adjacent cylinder misfire, steps 303 and 304 may be performed, and the timing for specifically performing steps 303 and 304 is determined by the piston motion position.

Specifically, a first speed of the crankshaft when the crankshaft rotates a preset angle after the piston in the target cylinder moves to the top dead center may be determined in the speed signal. After the piston moves to the top dead center, the piston moves downwards and applies full force to push the crankshaft to rotate, so that when the piston moves to the top dead center and the crankshaft rotates for a certain angle, the crankshaft can reach a faster rotating speed. The preset angle may be specifically set according to the engine structure and experience. For example, it may be set to 60 degrees.

Further, a second speed of the crankshaft when the piston in the target cylinder moves to the top dead center may be obtained. When the piston moves to the top dead center, the kinetic energy output by the piston is the lowest, the force pushing the crankshaft to rotate is the lowest, and the second speed of the crankshaft is the smallest.

In practical application, when the scheme can obtain the output kinetic energy of the target cylinder, the crankshaft rotates at a higher first speed and at a lower second speed.

And step 305, determining a misfiring cylinder in the target cylinders according to the misfire pattern and the first speed and the second speed corresponding to each target cylinder.

The specific principle and implementation of step 305 are similar to those of step 204, and are not described herein again.

Fig. 4 is a flowchart illustrating a misfire cylinder determination method in accordance with a third exemplary embodiment of the present invention.

As shown in fig. 4, the present embodiment provides a misfire cylinder determination method including:

in step 401, a misfire pattern of an engine is determined.

And step 402, acquiring a speed signal according to a gear ring speed measuring mechanism arranged at the flywheel end of the crankshaft.

Steps 401 and 402 are similar to steps 301 and 302 in specific principles and implementation, and are not described herein again.

If the determined misfire pattern is any one of a single cylinder misfire, a symmetric cylinder misfire, an adjacent cylinder misfire, the steps of steps 403 or 404 may be performed.

In step 403, a first sub-speed of the crankshaft when the crankshaft rotates by a first preset angle after the piston in the target cylinder moves to the top dead center and a second sub-speed of the crankshaft when the crankshaft rotates by a second preset angle are determined in the speed signal.

In the method provided by this embodiment, due to the influence of the structural connection relationship in the engine, when the crankshaft rotates by a first preset angle after the piston in the target cylinder moves to the top dead center, the crankshaft may not reach the fastest speed, so that the second sub-speed of the crankshaft when the crankshaft rotates by a second preset angle after the piston in the target cylinder moves to the top dead center can be obtained, and the fastest speed reached by the crankshaft when the target cylinder does work is predicted by the two sub-speeds.

Specifically, the second sub-speed is a speed adjacent to the first sub-speed, for example, the flywheel includes 60 gears, and the first sub-speed is collected when the crankshaft rotates by 60 degrees, and the speed collected when the crankshaft rotates by 54 degrees or 66 degrees can be used as the second sub-speed.

The first preset angle and the second preset angle are different by an angle value between two adjacent gears of the flywheel. The difference value between the first preset angle and the second preset angle is equal to the angle value between two adjacent gears on the flywheel. Specifically, the center of the flywheel can be used as a circle center to determine two adjacent gear angles.

The method provided by the embodiment is that the crankshaft rotating speed is determined according to the fact that the gear passes through the speed measuring mechanism. Therefore, each gear can be considered as a sampling point, the first preset angle and the second preset angle are set to be different from each other by an angle value between the two gears, the speed of the sampling point when the crankshaft reaches the position near the fastest speed can be obtained, and the obtained speed can be further used as the fastest speed to be processed.

In the speed signal, a third sub-speed of the crankshaft when the piston in the target cylinder moves to the top dead center and a fourth sub-speed of the crankshaft when the crankshaft rotates by a fourth preset angle are determined, step 404.

In the method provided by the embodiment, due to the influence of the structural connection relationship in the engine, the crankshaft may not reach the lowest speed when the piston in the target cylinder moves to the top dead center, so that the fourth sub-speed of the crankshaft when the crankshaft rotates by the fourth preset angle after the piston in the target cylinder moves to the top dead center can be obtained, and the lowest speed reached by the crankshaft when the target cylinder does work is predicted through the third sub-speed and the fourth sub-speed.

Specifically, the fourth sub-speed is a speed close to the third sub-speed, for example, if the flywheel includes 60 gears, the third sub-speed is collected when the piston moves to the top dead center, and the fourth sub-speed of the crankshaft is collected when the crankshaft rotates by 6 degrees.

Further, the fourth preset angle is an angle value between two adjacent gears of the flywheel. The method provided by the embodiment is that the crankshaft rotating speed is determined according to the fact that the gear passes through the speed measuring mechanism. Therefore, each gear can be considered as a sampling point, the fourth preset angle is set to be an angle value which is different between the two gears, the speed of the sampling point when the crankshaft reaches the position near the lowest speed can be obtained, and the obtained speed can be further used as the lowest speed to be processed.

The timing of execution of steps 403, 404 is not limited.

And step 405, determining the misfire index corresponding to the target cylinder according to the first sub-speed, the second sub-speed, the third sub-speed and the fourth sub-speed.

In practical application, the fastest speed of the target cylinder when pushing the crankshaft to rotate can be measured through the first sub-speed and the second sub-speed, and the lowest speed of the target cylinder when pushing the crankshaft to rotate can be measured through the third sub-speed and the fourth sub-speed. And then the speed of the crankshaft under the action of the target cylinder is measured by the four speeds.

If the cylinder misfires, the speed of the cylinder pushing the crankshaft to rotate differs from the speed of the cylinder in normal operation pushing the crankshaft to rotate, so that the misfire index corresponding to the target cylinder can be determined according to the first sub-speed, the second sub-speed, the third sub-speed and the fourth sub-speed. And determining the misfiring cylinders according to the misfiring indexes of the cylinders.

Specifically, the misfire index may be determined by the following equation:

I＝(αs_e-1+(1-α)s_e)-(αs_t+1+(1-α)s_t)

wherein I is the misfire index, s_e-1Is the second sub-speed, s_eIs the first sub-speed, s_t+1Is the fourth sub-speed, s_tIs the third sub-speed. α is a preset smoothing coefficient, and can be taken as needed, for example, 0.2.

And 406, determining a misfiring cylinder in the target cylinders according to the misfiring mode and the misfiring indexes of the target cylinders.

Specifically, the misfire index is an index determined according to the speed generated by the target cylinder pushing the crankshaft to rotate, and can be used for measuring the work-doing capacity of the target cylinder. Therefore, it is possible to determine a misfiring cylinder among the target cylinders according to the misfire pattern, the misfire index of each target cylinder.

In one case, if the misfire pattern is a single cylinder misfire, the target cylinder with the smallest misfire index may be determined as the misfiring cylinder. As can be seen from the formula for determining the misfire index, the misfire index may be used to represent the difference between the fastest and lowest speeds of the crankshaft as the target cylinder is pushing the crankshaft to rotate. If the cylinder catches fire, the power of the cylinder for pushing the crankshaft to rotate is reduced, and further the fastest speed of the crankshaft is reduced, so that the value of the fire catching index is reduced, therefore, if the fire catching mode is single-cylinder fire catching, the target cylinder with the minimum fire catching index can be determined as the fire catching cylinder.

In one case, if the misfire pattern is a symmetric cylinder misfire, the two symmetric cylinders with the smallest sum of misfire indexes may be identified as the misfiring cylinders. If the cylinder catches fire, the power for pushing the crankshaft to rotate is reduced, the fastest speed of the crankshaft is further reduced, and the value of the fire catching index is reduced, so that the fire catching indexes of the cylinders which are symmetrical in pairs can be added to obtain a first index sum, and the first index sum and the two smallest symmetrical cylinders are determined as the fire catching cylinders.

For an inline six cylinder engine, the symmetric cylinders therein may be determined according to the work order of the individual cylinders. In the engine, a cylinder 1, a cylinder 2, a cylinder 3, a cylinder 4, a cylinder 5, and a cylinder 6 are arranged in this order. In general, the working sequence is cylinder 1, cylinder 5, cylinder 3, cylinder 6, cylinder 2, and cylinder 4. In this case, the combination of the symmetric cylinders is: cylinders 1 and 6, cylinders 5 and 2, and cylinders 3 and 4.

In one case, if the misfire pattern is adjacent cylinder misfire, the two adjacent cylinders with the smallest sum of misfire indices are identified as misfiring cylinders. If the cylinder catches fire, the power for pushing the crankshaft to rotate is reduced, the fastest speed of the crankshaft is further reduced, and the value of the fire catching index is reduced, so that the fire catching indexes of every two adjacent cylinders can be added to obtain a second index sum, and the second index sum and the two smallest adjacent cylinders are determined as the fire catching cylinders.

For an inline six cylinder engine, the symmetric cylinders therein may be determined according to the work order of the individual cylinders. In the engine, a cylinder 1, a cylinder 2, a cylinder 3, a cylinder 4, a cylinder 5, and a cylinder 6 are arranged in this order. In general, the working sequence is cylinder 1, cylinder 5, cylinder 3, cylinder 6, cylinder 2, and cylinder 4. In this case, the combinations of adjacent cylinders are: cylinders 1 and 5, cylinders 5 and 3, cylinders 3 and 6, cylinders 6 and 2, cylinders 2 and 4, and cylinders 4 and 1.

Fig. 5 is a flowchart illustrating a misfire cylinder determination method in accordance with a fourth exemplary embodiment of the present invention.

As shown in fig. 5, the misfire cylinder determination method provided by the present embodiment includes:

in step 501, a misfire pattern of an engine is determined.

And 502, acquiring a speed signal according to a gear ring speed measuring mechanism arranged at the flywheel end of the crankshaft.

Steps 501 and 502 are similar to steps 301 and 302 in specific principle and implementation manner, and are not described herein again.

If the determined misfire pattern is in every one cylinder misfire, step 503 may be performed.

In the speed signal, a plurality of first speeds of the crankshaft from the time the crankshaft rotates by a first preset angle to the time the piston of the cylinder next to the target cylinder moves to the top dead center after the piston in the target cylinder moves to the top dead center are determined, in step 503.

If one cylinder is on fire at intervals, for example, the first cylinder doing work is on fire, the second cylinder doing work is in normal operation, and the third cylinder doing work is on fire, the misfiring cylinder cannot be inferred according to the instantaneous speed of the cylinder pushing the crankshaft due to interference among the cylinders. Therefore, if it is determined that the misfire pattern is an interval-cylinder misfire, it is possible to acquire the continuous velocity of the crankshaft by one cylinder, and thereby estimate whether the cylinder misfires based on the continuous velocity.

Specifically, for the target cylinder, the crankshaft may rotate by a first preset angle after the piston of the target cylinder moves to the top dead center until the piston of the next cylinder of the target cylinder moves to the top dead center at a plurality of first speeds of the crankshaft. When the piston of the target cylinder moves to the top dead center and the crankshaft rotates by a first preset angle, the crankshaft may reach the fastest rotation speed, and after the piston of the next cylinder moves to the top dead center, the next cylinder is used as the main power output. Therefore, the process of the piston moving to the top dead center from the first preset angle of rotation of the crankshaft until the piston of the cylinder next to the target cylinder moves to the top dead center may be regarded as the process of the kinetic energy output of the target cylinder. The speed of the crankshaft of this process can be captured for measurement of the kinetic energy of the target cylinder output.

Further, in this process, a plurality of first speeds can be obtained, and the crankshaft speed can be determined by detecting the time difference of every two adjacent gears passing through the gear ring speed measuring mechanism in this process.

The first predetermined angle may be the same as the first predetermined angle in the above embodiments, and is 60 degrees.

Step 504, a plurality of corresponding second speeds are determined according to the plurality of first speeds.

And when the device is actually applied, the corresponding second speed is determined according to each first speed.

Specifically, the auxiliary line may be determined according to a fifth sub-speed of the crankshaft when the crankshaft rotates by a first preset angle after the piston in the target cylinder moves to the top dead center, and a sixth sub-speed of the crankshaft when the piston in the next cylinder of the target cylinder moves to the top dead center. For example, a line connecting the fifth sub-velocity and the sixth sub-velocity may be drawn according to the first velocity, resulting in an auxiliary line.

A plurality of second speeds corresponding to each of the first speeds are determined based on the auxiliary line and the plurality of first speeds. A second speed corresponding to each first speed may be determined on the auxiliary line.

Fig. 6 is a schematic diagram of an auxiliary line according to an exemplary embodiment of the present invention.

As shown in fig. 6, the graph is used to show the velocity signal, the abscissa is used to represent the angle of rotation of the crankshaft after the piston reaches top dead center, and the ordinate is used to show the velocity of each sampling point. As shown in the figure, the speed of the crankshaft at which the crankshaft rotates by a first preset angle after the piston of the target cylinder reaches the top dead center and the speed of the crankshaft at which the piston of the cylinder next to the target cylinder moves to the top dead center can be connected to obtain the auxiliary line.

Wherein, the next cylinder of the target cylinder is determined according to the working sequence of the cylinders.

Specifically, in the auxiliary line, the second speed corresponding to each first speed may be determined. Specifically, in the auxiliary line, a velocity value having the same angle as the first velocity may be determined as the second velocity. For example, a vertical line passing through the first velocity point may be determined, and an intersection point of the vertical line and the auxiliary line may be determined, where the velocity value corresponding to the intersection point is the second velocity.

And 505, determining a misfire index corresponding to the target cylinder according to the first speed and the second speed.

Further, the first speed is an actual speed of the crankshaft, and the second speed is a virtual speed of the crankshaft, from which a speed variation tendency of the crankshaft can be determined as the misfire index.

In practice, the misfire index may be determined according to the following equation:

J＝∑(s_i-s′_i)

wherein J is the misfire index, s_iIs the first speed, s_i' is a second speed corresponding to the first speed.

And step 506, determining a misfiring cylinder in the target cylinder according to the misfiring index of each target cylinder.

Specifically, the cylinder group having the smallest misfire index value every one cylinder may be determined as the misfire cylinder. For example, the order of work performed by the cylinders is 1, 5, 3, 6, 2, 4, and assuming that the misfire index values of the cylinders 1 and 3 are the smallest, the cylinders 1 and 3 can be considered as misfiring cylinders.

Optionally, in the above embodiment, after obtaining the speed signal of the crankshaft when the engine is running, the method may further include:

the noise signal in the velocity signal is removed.

The dragging signal of the engine can be calibrated in advance, and the dragging signal is removed from the acquired speed signal, so that the purpose of removing the noise signal in the speed signal is achieved.

Specifically, after removing the noise signal in the speed signal or acquiring the speed signal, the method provided by this embodiment may further include:

an acceleration is determined from the velocity signal, and a trend component in the velocity signal is removed from the acceleration.

During smooth engine operation, the output speed signal should exhibit a periodic variation, e.g., the speed profile during the first and second operating cycles should be the same. However, there may be acceleration or deceleration conditions during actual driving, in which case the periodicity of the acquired speed signal may be affected.

The acceleration of the vehicle may be determined from the speed change, and may specifically be a number greater than 0, such as when the vehicle is accelerating, or may be a number less than 0, such as when the vehicle is decelerating. The trend component in the speed signal may be removed based on the determined acceleration, enabling a periodic signal of the speed of the engine output to be recovered.

Fig. 7A and 7B are schematic views each showing a misfire index in accordance with an exemplary embodiment of the present invention.

Fig. 7A shows a misfire index (ordinate is misfire index) when each cylinder misfires under the operating condition of engine speed 800 rpm and load 200 N.M. By taking the non-misfire condition as an example, the misfire indexes of all the cylinders are balanced, and by taking the cylinder 1 as an example of misfire, the misfire indexes of the cylinder 1 are obviously smaller than those of other cylinders, so that the misfire cylinders can be directly determined. The other cases are similar and will not be described again.

FIG. 7B is a misfire index when each cylinder misfires under operating conditions of engine speed 1800 rpm and load 200 N.M. The principle of fig. 7B is similar to that of fig. 7A, and it can be seen that, under the condition of high rotation speed, the misfiring cylinder can still be determined according to the misfire index, so that the accuracy of determining the misfiring cylinder by the scheme is high.

Fig. 8 is a structural diagram illustrating a misfire cylinder determining apparatus according to an exemplary embodiment of the present invention.

As shown in fig. 8, the present embodiment provides a misfire cylinder determining apparatus including:

a mode determination module 81 for determining a misfire mode of the engine;

the speed determining module 82 is configured to obtain a speed signal of a crankshaft when the engine operates, and obtain a first speed and a second speed corresponding to a target cylinder in the speed signal according to a motion position of a piston in the target cylinder when the engine operates;

and the misfiring cylinder determining module 83 is configured to determine a misfiring cylinder in the target cylinders according to the misfire pattern, the first speed and the second speed corresponding to each target cylinder.

The misfire cylinder determining apparatus provided in this embodiment is similar to the embodiment shown in fig. 2 and will not be described in detail.

Fig. 9 is a structural view of a misfire cylinder determining apparatus shown in another exemplary embodiment of the present invention.

As shown in fig. 9, the misfire cylinder determining apparatus provided in the present embodiment is based on the above embodiment, and optionally, the speed determining module 82 is specifically configured to:

and acquiring the speed signal according to a gear ring speed measuring mechanism arranged at the flywheel end of the crankshaft.

Optionally, if the misfire pattern comprises any one of the following:

single cylinder fire, symmetric cylinder fire, adjacent cylinder fire;

the speed determination module 82 is specifically configured to:

determining, in the speed signal, a first speed of the crankshaft when the crankshaft rotates a preset angle after a piston in the target cylinder moves to a top dead center;

in the speed signal, a second speed of the crankshaft is determined when a piston in the target cylinder moves to top dead center.

Optionally, if the misfire pattern comprises any one of the following:

single cylinder fire, symmetric cylinder fire, adjacent cylinder fire;

the first speed comprises a first sub-speed, a second sub-speed; the second speed comprises a third sub-speed and a fourth sub-speed;

the speed determination module 82 is specifically configured to:

determining, in the speed signal, a first sub-speed of the crankshaft when the crankshaft rotates by a first preset angle after the piston in the target cylinder moves to a top dead center, and a second sub-speed of the crankshaft when the crankshaft rotates by a second preset angle;

in the speed signal, a third sub-speed of the crankshaft when the piston in the target cylinder moves to top dead center, and a fourth sub-speed of the crankshaft when the crankshaft rotates a fourth preset angle are determined.

Optionally, the first preset angle and the second preset angle are different by an angle value between two adjacent gears of the flywheel.

Optionally, the fourth preset angle is an angle value between two adjacent gears of the flywheel.

Optionally, if the misfire pattern comprises any one of the following:

single cylinder fire, symmetric cylinder fire, adjacent cylinder fire;

the misfiring cylinder determining module 83 is specifically configured to:

determining a misfire index corresponding to the target cylinder according to the first sub-speed, the second sub-speed, the third sub-speed and the fourth sub-speed;

and determining the misfiring cylinder in the target cylinder according to the misfire pattern and the misfire index of each target cylinder.

Optionally, the ignition cylinder determining module 83 is specifically configured to:

if the misfire mode is single-cylinder misfire, determining the target cylinder with the minimum misfire index as a misfire cylinder;

and or if the misfire pattern is symmetrical cylinder misfire, determining two symmetrical cylinders with the smallest sum of the misfire indexes as misfiring cylinders;

and or if the misfire pattern is that the adjacent cylinders misfire, determining two adjacent cylinders with the smallest sum of the misfire indexes as the misfiring cylinders.

Optionally, if the misfire pattern is an alternate cylinder misfire;

the speed determination module 82 is specifically configured to:

determining a plurality of first speeds of the crankshaft in the process that the piston of the next cylinder of the target cylinder moves to the top dead center when the crankshaft rotates by a first preset angle after the piston in the target cylinder moves to the top dead center in the speed signal;

and determining a plurality of corresponding second speeds according to the plurality of first speeds.

Optionally, the speed determination module 82 is specifically configured to:

determining an auxiliary line according to a fifth sub-speed of the crankshaft when the crankshaft rotates by a first preset angle after the piston in the target cylinder moves to a top dead center and a sixth sub-speed of the crankshaft when the piston of a next cylinder of the target cylinder moves to the top dead center;

and determining a plurality of second speeds corresponding to each first speed according to the auxiliary line and the plurality of first speeds.

Optionally, if the misfire pattern is a cylinder misfire at intervals, the misfire cylinder determination module 83 is specifically configured to:

determining a misfire index corresponding to the target cylinder according to the first speed and the second speed;

and determining the misfiring cylinder in the target cylinder according to the misfiring index of each target cylinder.

Optionally, the ignition cylinder determining module 83 is specifically configured to:

and determining the two target cylinders which are separated by one cylinder and have the smallest sum of the misfire indexes.

Optionally, the apparatus preferably includes a signal processing module 84 for removing noise from the speed signal after the speed determination module 82 obtains the speed signal of the crankshaft during engine operation.

Optionally, the signal processing module 84 is further configured to:

and determining acceleration according to the speed signal, and removing a trend component in the speed signal according to the acceleration.

The apparatus provided in this embodiment is similar to the embodiments shown in fig. 3-7B, and is not described again.

Fig. 10 is a block diagram illustrating a misfire cylinder determining apparatus according to an exemplary embodiment of the present invention.

As shown in fig. 10, the present embodiment provides the misfire cylinder determining apparatus including:

a memory 101;

a processor 102; and

a computer program;

wherein the computer program is stored in the memory 101 and configured to be executed by the processor 102 to implement any of the misfire cylinder determination methods as described above.

The present embodiments also provide a computer-readable storage medium, having stored thereon a computer program,

the computer program is executed by a processor to implement any of the misfire cylinder determination methods described above.

The present embodiment also provides a computer program comprising program code for executing any one of the misfire cylinder determination methods as described above when the computer program is run by a computer.

Those of ordinary skill in the art will understand that: all or a portion of the steps of implementing the above-described method embodiments may be performed by hardware associated with program instructions. The program may be stored in a computer-readable storage medium. When executed, the program performs steps comprising the method embodiments described above; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.