Single cylinder power-on time correction method and system based on engine speed signal

Abstract

The application discloses a single-cylinder electrification time correction method and system based on an engine rotating speed signal and belongs to the technical field of engines, and the method comprises the following steps: after the engine is in a stable working condition, for each cylinder of the engine, a first time is obtained when the cylinder fires and turns through a corresponding crank angle, and a second time is obtained when the cylinder misfires and turns through the corresponding crank angle; according to the first time, the second time and the corresponding crank angle, the crank speed gain of the cylinder is determined; according to the crank speed gain of all the cylinders, the average rotating speed gain of the engine is determined; the electrification time of the cylinder whose crank speed gain is located outside the set threshold range of the average rotating speed gain of the engine is corrected, so that the crank speed gain of each cylinder after the electrification time correction is located within the set threshold range of the average rotating speed gain of the engine after the electrification time correction. Through the correction of the electrification time of each cylinder of the engine, the consistency of the work of each cylinder of the engine is realized.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and in particular to a method and system for correcting the single-cylinder energization time based on engine speed signals. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Due to differences in the processing of components in each cylinder, assembly deviations, and inconsistencies in the intake and fuel systems, the work capacity of each cylinder in a multi-cylinder diesel engine is not completely consistent when the engine is running stably under a certain operating condition, resulting in uneven work capacity among the cylinders.

[0004] The existing method for improving the consistency of power output of each cylinder in an engine is as follows: during one working cycle of the engine, the difference between the maximum and minimum instantaneous speed of each cylinder during the expansion phase is obtained, and the average speed difference of each cylinder is averaged to obtain the average speed difference. Based on the relationship between the instantaneous speed difference of each cylinder and the average speed difference, the correction parameters of each cylinder are determined, and the energizing time of each cylinder is corrected to improve the consistency of power output of each cylinder in the engine.

[0005] The inventors believe that at present, it is impossible to accurately identify the cylinder expansion stage and obtain the instantaneous maximum and minimum speed of the cylinder, resulting in inaccurate instantaneous speed difference and average speed difference of the cylinder, which in turn leads to limited improvement in the consistency of power output of each cylinder of the engine. Summary of the Invention

[0006] To address the aforementioned problems, this invention proposes a single-cylinder power-on time correction method and system based on engine speed signals. By comparing the crankshaft speed gain of each cylinder with the average engine speed gain, it determines whether the power-on time of the cylinder needs to be corrected. After correcting the power-on time of the cylinders that require correction, the consistency of power output of each cylinder in the engine is achieved.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] Firstly, a single-cylinder energization time correction method based on engine speed signal is proposed, including:

[0009] After the engine is in a stable operating condition, for each cylinder of the engine, the first time when the cylinder rotates through the corresponding crankshaft angle when it fires and the second time when it rotates through the corresponding crankshaft angle when it misfires are obtained; based on the first time, the second time and the corresponding crankshaft angle, the crankshaft speed gain of the cylinder is determined.

[0010] The engine average speed gain is determined based on the crankshaft speed gain of all cylinders.

[0011] For cylinders whose crankshaft speed gain is outside the set threshold range of engine average speed gain, the power-on time is corrected so that the crankshaft speed gain of each cylinder after power-on time correction is within the set threshold range of engine average speed gain after power-on time correction.

[0012] Secondly, a single-cylinder energization time correction system based on engine speed signal is proposed, including:

[0013] The cylinder crankshaft speed gain acquisition module is used to acquire the first time when the cylinder rotates through the corresponding crankshaft angle during firing and the second time when it rotates through the corresponding crankshaft angle during misfiring for each cylinder of the engine after the engine is in a stable operating condition; and to determine the crankshaft speed gain of the cylinder based on the first time, the second time and the corresponding crankshaft angle.

[0014] The engine average speed gain acquisition module is used to determine the engine average speed gain based on the crankshaft speed gain of all cylinders.

[0015] The power-on time correction module is used to correct the power-on time of cylinders whose crankshaft speed gain is outside the set threshold range of the engine average speed gain, so that the crankshaft speed gain of each cylinder is within the set threshold range of the engine average speed gain after the power-on time correction.

[0016] Thirdly, an electronic device is proposed, including a memory and a processor, and computer instructions stored in the memory and running on the processor, wherein the computer instructions, when executed by the processor, complete the steps described in a single-cylinder power-on time correction method based on an engine speed signal.

[0017] Fourthly, a computer-readable storage medium is proposed for storing computer instructions, which, when executed by a processor, complete the steps described in a single-cylinder power-on time correction method based on engine speed signals.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. This invention determines whether the cylinder's power-on time needs to be corrected by comparing the crankshaft speed gain of each cylinder with the engine's average speed gain. The power-on time of the cylinders that need correction is corrected until the crankshaft speed gain of each cylinder after the power-on time correction is all within the set threshold range of the engine's average speed gain after the power-on time correction, thereby achieving consistency in the work done by each cylinder of the engine.

[0020] 2. This invention uses the crankshaft speed gain of the cylinder as the standard for whether to perform power-on time correction. It does not require accurate identification of the cylinder expansion stage, thus solving the technical problem that the current stage cannot accurately identify the cylinder expansion stage, resulting in inaccurate instantaneous speed difference and average speed difference of the cylinder, which in turn leads to limited improvement effect on the consistency of power output of each cylinder of the engine.

[0021] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0023] Figure 1 This is a flowchart illustrating the determination process for whether a cylinder needs power-on time correction, as disclosed in Example 1.

[0024] Figure 2 This is a flowchart of the positive correction of power-on time disclosed in Example 1. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0027] Example 1

[0028] To achieve consistent power output across all engine cylinders, this embodiment discloses a single-cylinder power-on time correction method based on engine speed signals, such as... Figure 1 As shown, it includes:

[0029] S1: After the engine is in a stable operating condition, for each cylinder of the engine, obtain the first time when the cylinder rotates through the corresponding crankshaft angle when it fires, and the second time when it rotates through the corresponding crankshaft angle when it misfires; determine the crankshaft speed gain of the cylinder based on the first time, the second time, and the corresponding crankshaft angle.

[0030] This embodiment obtains the first moment when each cylinder fires after all cylinders of the engine have completed one working cycle.

[0031] If one cylinder of the engine misfires, the other cylinders will fire, completing one working cycle of the engine. The second time of the misfired cylinder is obtained, and the fuel injection quantity of the firing cylinder is the same as that of the cylinder when the first time of the cylinder is obtained during this working cycle.

[0032] Calculate the difference between the second time and the first time, and the ratio of this difference to the corresponding crankshaft angle is the crankshaft speed gain of the cylinder.

[0033] The working cycle of an engine consists of four strokes: intake, compression, combustion, and exhaust. When an engine completes these four strokes, it has completed one working cycle.

[0034] The energizing time refers to the time during which the engine controller energizes the electronic fuel injector, enabling it to perform injection.

[0035] Assuming the diesel engine has X cylinders, the cylinders are ordered according to the firing order, with the firing intervals from cylinder 1 to cylinder X being D1, D2, D3, ... D... X-1 .

[0036] If the crankshaft angle corresponding to the top dead center of piston n is set to 0°, then the crankshaft rotation angle between the top dead center of piston n and piston n+1 is D. n °.

[0037] When the engine is operating under a certain stable condition, all cylinders fire. For any cylinder n, obtain the crankshaft angle from 0° to D during an engine working cycle. n ° time t o Time t o That is, the crankshaft rotation angle D when cylinder n fires. n The first step is to shut off the fuel injector function of cylinder n, causing cylinder n to misfire. All cylinders except cylinder n continue firing, and the fuel injection quantity remains unchanged, to begin the next engine working cycle. During this cycle, the crankshaft angle of the misfired cylinder n changes from 0° to D°. n ° time t c Time t c That is, when cylinder n misfires, it rotates through the corresponding crankshaft angle D. n ° Second time.

[0038] According to the first time t o Time t c and the corresponding crankshaft rotation angle D n °, determine the crankshaft speed gain V of cylinder n. n :

[0039]

[0040] Using the above method, the crankshaft speed gain of cylinders one through X is calculated sequentially.

[0041] S2: Determine the engine average speed gain based on the crankshaft speed gain of all cylinders.

[0042] The average crankshaft speed gain of all cylinders is taken as the average value to obtain the engine average speed gain V. ave .

[0043]

[0044] Among them, V X Let X be the crankshaft speed gain of cylinder X, where X is the total number of cylinders.

[0045] S3: Correct the power-on time for cylinders whose crankshaft speed gain is outside the set threshold range of engine average speed gain, so that the crankshaft speed gain of each cylinder after power-on time correction is within the set threshold range of engine average speed gain after power-on time correction.

[0046] By comparing the crankshaft speed gain of the cylinder with the average speed gain of the engine, it is determined whether the cylinder's energizing time needs to be corrected.

[0047] When the crankshaft speed gain of a cylinder is outside the set threshold range of the engine average speed gain, it is determined that the cylinder needs to be corrected for the power-on time; when the crankshaft speed gain of a cylinder is within the set threshold range of the engine average speed gain, it is determined that the cylinder does not need to be corrected for the power-on time.

[0048] The engine average speed gain setting threshold range is: [Vave + Vs, Vave - Vs], where V S To set a threshold.

[0049] For a cylinder that satisfies formula (3), it means that the crankshaft speed gain of the cylinder is within the set threshold range of the engine average speed gain, and the energizing time of the cylinder does not need to be corrected.

[0050] Vn∈

Vave+Vs, Vave-Vs

[0051] For cylinders that do not conform to formula (3), it means that the crankshaft speed gain of the cylinder is outside the set threshold range of the engine average speed gain, and the power-on time of the cylinder needs to be corrected.

[0052] The power-on time of the cylinders that need to be corrected is corrected at least once. For each round of correction, the power-on time of all cylinders that need to be corrected is corrected, and the crankshaft speed gain of each cylinder after the round of correction is obtained.

[0053] Based on the crankshaft speed gain of all cylinders after the round correction, the average engine speed gain after the round correction is obtained.

[0054] When the crankshaft speed gain of all cylinders after the correction is within the set threshold range of the engine average speed gain after the correction, the correction is stopped.

[0055] If the crankshaft speed gain of a cylinder after the current correction is outside the set threshold range of the engine average speed gain after the current correction, the next round of power-on time correction will be performed for that cylinder.

[0056] In addition, in order to ensure the smooth progress of the power-on time correction, this embodiment limits the correction round k to a maximum of a set correction round threshold K. When the correction round k equals the set correction round threshold K, the correction process ends.

[0057] When correcting the cylinder's energizing time, the relationship between the cylinder's crankshaft speed gain and the engine's average speed gain threshold range is also considered to perform positive or negative corrections on the cylinder's energizing time. This ensures the accuracy of the energizing time correction direction and improves the efficiency of the correction. Specifically, for cylinders whose crankshaft speed gain is less than the lower limit of the engine's average speed gain threshold range, negative energizing time correction is performed; for cylinders whose crankshaft speed gain is greater than the upper limit of the engine's average speed gain threshold range, positive energizing time correction is performed.

[0058] Furthermore, this embodiment also determines the cumulative correction ratio based on the correction ratio of each round and the number of correction rounds, and uses the cumulative correction ratio to perform the next round of correction on the power-on time obtained after the correction rounds.

[0059] like Figure 2 As shown, when V n >V ave +V s Then, the energizing time of cylinder n is positively corrected, with the correction multiplier set to r per round, the number of corrected rounds being k, and the energizing time obtained after k corrected rounds being T. n The cumulative correction ratio is determined by the correction ratio r and the number of correction cycles k. The cumulative correction ratio = r * k. The power-on time T obtained after the correction cycle k is then calculated using r * k. n Perform the next round of correction to obtain the power-on time T after the corrected round k+1. n The power-on time T obtained after round k+1 has been corrected. n = The power-on time T obtained after correcting round k n *(1-r*k).

[0060] If V n <V ave +V sThen, the energizing time of cylinder n is negatively corrected. The difference between negative and positive correction is that, during negative correction, the energizing time T obtained after correction cycle k+1 is already corrected. n = The power-on time T obtained after correcting round k n *(1+r*k).

[0061] Obtain the power-on time T after the corrected round k+1. n When the electric motor is doing work, the crankshaft speed gain V of cylinder n n This allows us to obtain the engine's average speed gain V after the current power-on time correction. ave If V here n and V ave If equation (3) is satisfied, the correction ends, the correction count is cleared to 0, k = 0, and the cylinder energizing time correction state is exited; if V here n and V ave If equation (3) is not satisfied, the energizing time correction will continue for the cylinder that does not satisfy equation (3) until V. n When equation (3) is satisfied or the number of corrections reaches the set correction round threshold K, the correction ends, the correction count is cleared to 0, k = 0, and the cylinder power-on time correction state is exited.

[0062] This embodiment discloses a method that determines whether the cylinder's energizing time needs correction by comparing the crankshaft speed gain of each cylinder with the engine's average speed gain. The method then corrects the energizing time of the cylinders requiring correction. When the crankshaft speed gain of each cylinder after correction is entirely within a set threshold range for the engine's average speed gain after correction, the correction is complete, achieving consistency in the power output of each cylinder. This method eliminates the need for accurate determination of the cylinder's expansion stage, requires no additional sensors or equipment, and necessitates no engine modifications. It offers excellent real-time performance while also being simple to operate, low-cost, and fast in correction.

[0063] The method disclosed in this embodiment determines the direction of the power-on time correction for each cylinder by using the relationship between the crankshaft speed gain of each cylinder and the average speed gain of the engine. When the power-on time of the cylinder is corrected by using this direction, the efficiency of the power-on time correction is improved while ensuring the accuracy of the power-on time correction.

[0064] The method disclosed in this embodiment corrects the power-on time of the cylinders that need correction in each round, and then performs engine power based on the corrected power-on time, thereby obtaining the crankshaft speed gain of each cylinder after correction and the crankshaft speed gain of each cylinder after correction, which improves the correction efficiency of power-on time, and at the same time ensures the accuracy of engine power consistency determination.

[0065] Example 2

[0066] In this embodiment, a single-cylinder energization time correction system based on engine speed signal is disclosed, comprising:

[0067] The cylinder crankshaft speed gain acquisition module is used to acquire the first time when the cylinder rotates through the corresponding crankshaft angle during firing and the second time when it rotates through the corresponding crankshaft angle during misfiring for each cylinder of the engine after the engine is in a stable operating condition; and to determine the crankshaft speed gain of the cylinder based on the first time, the second time and the corresponding crankshaft angle.

[0068] The engine average speed gain acquisition module is used to determine the engine average speed gain based on the crankshaft speed gain of all cylinders.

[0069] The power-on time correction module is used to correct the power-on time of cylinders whose crankshaft speed gain is outside the set threshold range of the engine average speed gain, so that the crankshaft speed gain of each cylinder is within the set threshold range of the engine average speed gain after the power-on time correction.

[0070] Example 3

[0071] In this embodiment, an electronic device is disclosed, including a memory and a processor, as well as computer instructions stored in the memory and running on the processor. When the processor executes the computer instructions, it completes the steps described in the single-cylinder power-on time correction method based on engine speed signal disclosed in Embodiment 1.

[0072] Example 4

[0073] In this embodiment, a computer-readable storage medium is disclosed for storing computer instructions, which, when executed by a processor, complete the steps described in the single-cylinder power-on time correction method based on engine speed signal disclosed in Embodiment 1.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for correcting the single-cylinder energization time based on engine speed signals, characterized in that, include: After the engine is in a stable operating condition, for each cylinder of the engine, the first time when the cylinder rotates through the corresponding crankshaft angle when it fires and the second time when it rotates through the corresponding crankshaft angle when it misfires are obtained; based on the first time, the second time and the corresponding crankshaft angle, the crankshaft speed gain of the cylinder is determined; the difference between the second time and the first time is calculated, and the ratio of this difference to the corresponding crankshaft angle is the crankshaft speed gain of the cylinder. The engine average speed gain is determined based on the crankshaft speed gain of all cylinders. For cylinders whose crankshaft speed gain is outside the set threshold range of engine average speed gain, the power-on time is corrected so that the crankshaft speed gain of each cylinder after power-on time correction is within the set threshold range of engine average speed gain after power-on time correction. The power-on time is corrected at least once. For each correction, the power-on time of all cylinders that need to be corrected is corrected, and the crankshaft speed gain of each cylinder after the correction is obtained. Based on the crankshaft speed gain of all cylinders after the round correction, the average engine speed gain after the round correction is obtained. When the crankshaft speed gain of all cylinders after the correction is within the set threshold range of the engine average speed gain after the correction, the correction is stopped. If the crankshaft speed gain of a cylinder after the current correction is outside the set threshold range of the engine average speed gain after the current correction, the next round of power-on time correction will be performed for that cylinder. The cumulative correction ratio is determined by the correction ratio in each round and the number of rounds already corrected. The power-on time obtained after the previous rounds is then corrected using the cumulative correction ratio in the next round.

2. The single-cylinder power-on time correction method based on engine speed signal as described in claim 1, characterized in that, All cylinders are fired to perform engine power, and the first moment of each cylinder's firing is captured.

3. The single-cylinder power-on time correction method based on engine speed signal as described in claim 1, characterized in that, If one cylinder misfires, the remaining cylinders will fire to power the engine, thus obtaining the second time of the misfired cylinder.

4. The single-cylinder power-on time correction method based on engine speed signal as described in claim 1, characterized in that, For cylinders where the crankshaft speed gain exceeds the upper limit of the set threshold range for the engine's average speed gain, a positive correction of the power-on time is performed.

5. The single-cylinder power-on time correction method based on engine speed signal as described in claim 1, characterized in that, For cylinders whose crankshaft speed gain is less than the lower limit of the set threshold range for engine average speed gain, a negative correction of the power-on time is performed.

6. A single-cylinder power-on time correction system based on engine speed signal, characterized in that, include: The cylinder crankshaft speed gain acquisition module is used to acquire, after the engine is in a stable operating condition, the first time when the cylinder rotates through the corresponding crankshaft angle during firing and the second time when it rotates through the corresponding crankshaft angle during misfiring for each cylinder of the engine; determine the crankshaft speed gain of the cylinder based on the first time, the second time and the corresponding crankshaft angle; calculate the difference between the second time and the first time, and the ratio of this difference to the corresponding crankshaft angle is the crankshaft speed gain of the cylinder; The engine average speed gain acquisition module is used to determine the engine average speed gain based on the crankshaft speed gain of all cylinders. The power-on time correction module is used to correct the power-on time of cylinders whose crankshaft speed gain is outside the set threshold range of engine average speed gain, so that the crankshaft speed gain of each cylinder is within the set threshold range of engine average speed gain after power-on time correction. The power-on time is corrected at least once. For each correction, the power-on time of all cylinders that need to be corrected is corrected, and the crankshaft speed gain of each cylinder after the correction is obtained. Based on the crankshaft speed gain of all cylinders after the round correction, the average engine speed gain after the round correction is obtained. When the crankshaft speed gain of all cylinders after the correction is within the set threshold range of the engine average speed gain after the correction, the correction is stopped. If the crankshaft speed gain of a cylinder after the current correction is outside the set threshold range of the engine average speed gain after the current correction, the next round of power-on time correction will be performed for that cylinder. The cumulative correction ratio is determined by the correction ratio in each round and the number of rounds already corrected. The power-on time obtained after the previous rounds is then corrected using the cumulative correction ratio in the next round.

7. An electronic device, characterized in that, It includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor, which, when executed by the processor, complete the steps of the single-cylinder power-on time correction method based on engine speed signal as described in any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, Used to store computer instructions, which, when executed by a processor, complete the steps of the single-cylinder power-on time correction method based on engine speed signal as described in any one of claims 1-5.

Images