A method and system for controlling a hydrogen internal combustion engine to improve transient response capability

Abstract

The present invention discloses a method for controlling a hydrogen internal combustion engine for improving transient response capability, which relates to internal combustion engine control technology. It determines whether the current operating condition of the hydrogen internal combustion engine is a transient operating condition according to the current power demand of the hydrogen internal combustion engine. If so, the transient factor of the current operating condition of the hydrogen internal combustion engine is calculated, and the air-fuel ratio and ignition advance angle of the hydrogen internal combustion engine are transiently enriched according to the transient factor. The present invention also discloses a control system for a hydrogen internal combustion engine for improving transient response capability. The present invention significantly improves the power response speed of the hydrogen internal combustion engine under transient conditions, thereby solving the problem of slow power response speed of the hydrogen internal combustion engine under transient conditions in the prior art.

Description

Technical Field

[0001] The present invention relates to internal combustion engine control technology, and more particularly, to a hydrogen internal combustion engine control method and system for improving transient response capability. Background Art

[0002] In order to improve the efficiency of energy use, the use of new energy engines in automobiles is an important means to achieve the "dual carbon" goal. Hydrogen energy is a common type of new energy. Due to its own characteristics, hydrogen energy has many advantages over traditional energy sources, such as hydrogen does not produce CO2 emissions after combustion. However, due to the high activity of hydrogen and the wide flammable boundary, the requirements for its application in hydrogen injectors are high. And because the air-fuel ratio control of hydrogen is related to NOx emissions (high emissions due to excessively rich air-fuel ratio) and power output (slow power response due to excessively lean air-fuel ratio), especially under transient conditions, the power output response speed of hydrogen internal combustion engines is slow, affecting the driving performance and user experience of the vehicle. In the prior art, although there are some methods for improving power response by adjusting the air-fuel ratio and the ignition advance angle, these methods have limited effects in practical applications and are difficult to accurately control. In order to solve the problem of transient responsiveness of hydrogen internal combustion engines, the present invention proposes a control method and system for hydrogen internal combustion engines for improving transient response capability. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a hydrogen internal combustion engine control method and system for improving transient response capability in view of the deficiencies in the prior art, thereby solving the problem of slow power response speed of hydrogen internal combustion engines under transient conditions in the prior art.

[0004] The present invention discloses a method for controlling a hydrogen internal combustion engine for improving transient response capability. It determines whether the current operating condition of the hydrogen internal combustion engine is a transient operating condition according to the current power demand of the hydrogen internal combustion engine. If so, it calculates the transient factor under the current operating condition of the hydrogen internal combustion engine, and performs transient enrichment control on the air-fuel ratio and ignition advance angle of the hydrogen internal combustion engine according to the transient factor.

[0005] Preferably, the transient enrichment control is:

[0006] Calibrate two ignition advance angle pulse spectra, namely a relatively rich ignition advance angle pulse spectrum and a relatively lean ignition advance angle pulse spectrum;

[0007] Acquiring an actual value of a target air-fuel ratio of the hydrogen internal combustion engine, and querying a target air-fuel ratio value from an air-fuel ratio concentration map of the hydrogen internal combustion engine according to the transient factor;

[0008] Determining the current hydrogen injection concentration in the hydrogen internal combustion engine according to the actual air-fuel ratio value and the target air-fuel ratio value;

[0009] If the actual air-fuel ratio value is greater than the target air-fuel ratio value, it is determined that the current hydrogen injection concentration is too rich, a rich ignition advance angle map is selected as the target ignition advance angle map, and an ignition advance angle corresponding to the actual air-fuel ratio value is searched from the rich ignition advance angle map;

[0010] If the actual air-fuel ratio value is less than the target air-fuel ratio value, it is determined that the current hydrogen injection concentration is lean, a lean ignition advance angle map is selected as the target ignition advance angle map, and the ignition advance angle corresponding to the actual air-fuel ratio value is queried from the lean ignition advance angle map.

[0011] Preferably, the air-fuel ratio concentration map comprises a rich map and a lean map, and selection of the air-fuel ratio concentration map is determined according to the transient factor.

[0012] Preferably, when the value of the transient factor is 100%, the concentrated pulse spectrum is selected as the current air-fuel ratio concentration pulse spectrum;

[0013] When the value of the transient factor is 0%, the lean map is selected as the current air-fuel ratio concentration map;

[0014] When the value of the transient factor is other values, the rich pulse spectrum and the lean pulse spectrum are interpolated and selected to determine the target air-fuel ratio of the hydrogen internal combustion engine.

[0015] Preferably, the target air-fuel ratio is determined as follows:

[0016] According to the transient factor, a first air-fuel ratio is obtained from a rich pulse spectrum, and a second air-fuel ratio is obtained from a lean pulse spectrum, and the target air-fuel ratio is calculated by the following formula:

[0017] α 目标 =α 1 ·r+α 2 (1-r);

[0018] Among them, α 目标 is the target air-fuel ratio, α 1 is the first air-fuel ratio, α 2 is the second air-fuel ratio, and r is the transient factor.

[0019] Preferably, the ignition advance angle is optimized according to the actual air-fuel ratio value and the target air-fuel ratio value.

[0020] Preferably, if it is determined that the current hydrogen injection concentration is too rich according to the actual air-fuel ratio value and the target air-fuel ratio value, a preset target step length is used as the increase basis of the ignition advance angle, and the ignition advance angle increases by one unit angle for each target step length difference between the actual air-fuel ratio value and the target air-fuel ratio value;

[0021] If it is determined that the current hydrogen injection concentration is lean based on the actual air-fuel ratio value and the target air-fuel ratio value, the target step length is used as the basis for reducing the ignition advance angle. For every target step length difference between the actual air-fuel ratio value and the target air-fuel ratio value, the ignition advance angle is reduced by one unit angle.

[0022] Preferably, the internal working condition of the hydrogen internal combustion engine is monitored, and if a signal of pre-ignition or knocking is detected in the hydrogen internal combustion engine, the optimization of the ignition advance angle is stopped.

[0023] Preferably, the transient factor is calculated by the following formula:

[0024]

[0025] Among them, r is the transient factor; P 0 is the boost pressure target value of the hydrogen internal combustion engine; P 1 is the actual value of the boost pressure of the hydrogen internal combustion engine; ΔP 1 is the preset boost pressure high pressure difference threshold; ΔP 2 is the preset boost pressure low differential pressure threshold.

[0026] A control system for implementing the method for controlling a hydrogen internal combustion engine for improving transient response capability, comprising:

[0027] A power demand identification module, used to identify the current power demand of the hydrogen internal combustion engine;

[0028] A transient factor calculation module, used to determine whether the current operating condition of the hydrogen internal combustion engine is a transient operating condition according to the current power demand of the hydrogen internal combustion engine, and if so, calculate the transient factor of the hydrogen internal combustion engine under the current operating condition;

[0029] The transient enrichment and ignition advance angle control module is used to perform transient enrichment control on the air-fuel ratio and ignition advance angle of the hydrogen internal combustion engine according to the transient factor.

[0030] Beneficial Effects

[0031] The advantages of the present invention are:

[0032] 1. Under transient conditions, the air-fuel ratio and ignition advance angle of the hydrogen internal combustion engine are transiently enriched according to the transient factor, which significantly improves the power response speed of the hydrogen internal combustion engine under transient conditions, thereby solving the problem of slow power response speed of the hydrogen internal combustion engine under transient conditions in the prior art.

[0033] 2. Through the calculation of transient factors and the selection of pulse spectra, more precise control is achieved, the adaptability and robustness of the system are improved, thereby improving the power output of the hydrogen internal combustion engine under transient conditions, and enhancing the vehicle's driving experience and user satisfaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic flow chart of a method for controlling a hydrogen internal combustion engine with improved transient response capability according to the present invention;

[0035] Figure 2 It is a schematic diagram of the transient factor calculation process of the present invention. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the embodiments, but it does not constitute any limitation to the present invention. Any limited number of modifications made by anyone within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0037] Embodiment 1

[0038] See also Figure 1 , a control method for a hydrogen internal combustion engine for improving transient response capability of the present invention, the method is:

[0039] First, the power demand of the hydrogen internal combustion engine is identified by collecting signals from the engine's speed sensor, boost pressure sensor, intake pressure sensor, throttle, accelerator pedal position, etc., and using the existing power demand model to identify the power demand.

[0040] After the current power demand of the hydrogen internal combustion engine is obtained, it is determined whether the current operating condition of the hydrogen internal combustion engine is a transient operating condition according to the current power demand of the hydrogen internal combustion engine. If the current operating condition is a transient operating condition, the transient factor of the hydrogen internal combustion engine under the current operating condition is calculated, and the air-fuel ratio and the ignition advance angle of the hydrogen internal combustion engine are transiently enriched according to the transient factor to improve the power response capability of the hydrogen internal combustion engine, thereby solving the problem of slow power response speed of the hydrogen internal combustion engine under transient operating conditions in the prior art.

[0041] like Figure 2 As shown, in this embodiment, the transient factor is calculated by the following formula:

[0042]

[0043] Among them, r is the transient factor; P 0 is the boost pressure target value of the hydrogen internal combustion engine; P 1 is the actual value of the boost pressure of the hydrogen internal combustion engine; ΔP 1 is the preset boost pressure high pressure difference threshold; ΔP 2 is the preset boost pressure low differential pressure threshold.

[0044] For transient enrichment control, the present invention adopts a dual-spectrum method to calibrate the air-fuel ratio and the ignition advance angle. The specific method is as follows:

[0045] The parameters of the working condition of the hydrogen internal combustion engine are calibrated on the engine bench. The boundary between the rich and lean hydrogen injection concentration is distinguished based on the working condition of the hydrogen internal combustion engine. The boundary adopts the boundary standard of the rich and lean hydrogen injection concentration of the hydrogen internal combustion engine, and finally the rich pulse spectrum and the lean pulse spectrum are obtained. In addition, two ignition advance angle pulse spectra need to be calibrated for the positive and negative deviations based on the air-fuel ratio target value, namely the rich ignition advance angle pulse spectrum and the lean ignition advance angle pulse spectrum.

[0046] When the hydrogen internal combustion engine is running, the actual value of the target air-fuel ratio of the hydrogen internal combustion engine is obtained, and the selection of the rich pulse spectrum or the lean pulse spectrum is determined from the two air-fuel ratio concentration pulse spectra according to the transient factor calculated above. The specific selection method is:

[0047] When the value of the transient factor is 100%, the rich pulse spectrum is selected as the current air-fuel ratio concentration spectrum, and then the air-fuel ratio target value is found from the rich pulse spectrum according to the transient factor.

[0048] When the value of the transient factor is 0%, the lean map is selected as the current air-fuel ratio concentration map, and the air-fuel ratio target value is found from the lean map according to the transient factor.

[0049] When the value of the transient factor is other values, the target air-fuel ratio of the hydrogen internal combustion engine is determined by interpolating the rich pulse spectrum and the lean pulse spectrum, and the target air-fuel ratio is the air-fuel ratio target value. Specifically, according to the transient factor, the first air-fuel ratio is found from the rich pulse spectrum, and the second air-fuel ratio is found from the lean pulse spectrum, and the target air-fuel ratio is calculated by the following formula:

[0050] α 目标 =α 1 ·r+α 2 (1-r);

[0051] Among them, α 目标 is the target air-fuel ratio, α 1 is the first air-fuel ratio, α 2 is the second air-fuel ratio, and r is the transient factor.

[0052] After determining the target value of the air-fuel ratio, the ignition advance angle can be queried. The specific method is: determine the current hydrogen injection concentration in the hydrogen internal combustion engine based on the actual value of the air-fuel ratio and the target value of the air-fuel ratio. If the actual value of the air-fuel ratio is greater than the target value of the air-fuel ratio, it is judged that the current hydrogen injection concentration is too rich, and a rich ignition advance angle pulse spectrum is selected as the target ignition advance angle pulse spectrum, and the ignition advance angle corresponding to the actual value of the air-fuel ratio is queried from the rich ignition advance angle pulse spectrum. If the actual value of the air-fuel ratio is less than the target value of the air-fuel ratio, it is judged that the current hydrogen injection concentration is too lean, and a lean ignition advance angle pulse spectrum is selected as the target ignition advance angle pulse spectrum, and the ignition advance angle corresponding to the actual value of the air-fuel ratio is queried from the lean ignition advance angle pulse spectrum. In this way, the air-fuel ratio and ignition advance angle parameters of hydrogen injection can be obtained, transient enrichment is achieved, and power output can be quickly increased under transient conditions.

[0053] In this embodiment, the ignition advance angle is also optimized according to the actual value of the air-fuel ratio and the target value of the air-fuel ratio to further improve the combustion efficiency and power output of the engine.

[0054] Specifically, if the current hydrogen injection concentration is judged to be rich based on the actual value of the air-fuel ratio and the target value of the air-fuel ratio, a preset target step size is used as the growth basis of the ignition advance angle, and the ignition advance angle increases by one unit angle for each target step size difference between the actual value of the air-fuel ratio and the target value of the air-fuel ratio. If the current hydrogen injection concentration is judged to be lean based on the actual value of the air-fuel ratio and the target value of the air-fuel ratio, the target step size is used as the reduction basis of the ignition advance angle, and the ignition advance angle decreases by one unit angle for each target step size difference between the actual value of the air-fuel ratio and the target value of the air-fuel ratio. Among them, the target step size can be set to 0.04, and the unit angle can be set to 1°. For example, if the actual value of the air-fuel ratio is 2.54, and the target value of the air-fuel ratio is 2.30, then the current hydrogen injection concentration is rich, and the difference between the two is 0.24, so the final increased ignition advance angle is 6°.

[0055] This embodiment dynamically adjusts the ignition advance angle to avoid the problem of knock or premature combustion when the air-fuel ratio is too rich and the ignition advance angle remains unchanged. However, if a signal of premature combustion or knock is detected in the hydrogen internal combustion engine, the optimization of the ignition advance angle is stopped.

[0056] Embodiment 2

[0057] A control system for implementing the above-mentioned hydrogen internal combustion engine control method for improving transient response capability comprises a power demand identification module, a transient factor calculation module and a transient enrichment and ignition advance angle control module.

[0058] Among them, the power demand identification module is used to realize the recognition of the current power demand of the hydrogen internal combustion engine in the above control method; the transient factor calculation module is used to realize the above control method to determine whether the current operating condition of the hydrogen internal combustion engine is a transient operating condition according to the current power demand of the hydrogen internal combustion engine, and if so, calculate the transient factor under the current operating condition of the hydrogen internal combustion engine; the transient enrichment and ignition advance angle control module is used to realize the above control method to perform transient enrichment control on the air-fuel ratio and ignition advance angle of the hydrogen internal combustion engine according to the transient factor. In this way, the power response capability of the hydrogen internal combustion engine can be improved, thereby solving the problem of slow power response speed of the hydrogen internal combustion engine under transient conditions in the prior art.

[0059] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A method for controlling a hydrogen internal combustion engine for improving transient response capability, characterized in that: It is determined whether the current operating condition of the hydrogen internal combustion engine is a transient operating condition according to the current power demand of the hydrogen internal combustion engine. If so, a transient factor under the current operating condition of the hydrogen internal combustion engine is calculated, and transient enrichment control is performed on the air-fuel ratio and ignition advance angle of the hydrogen internal combustion engine according to the transient factor.

2. A method for controlling a hydrogen internal combustion engine for improving transient response capability according to claim 1, characterized in that: The transient enrichment control is: Calibrate two ignition advance angle pulse spectra, namely a relatively rich ignition advance angle pulse spectrum and a relatively lean ignition advance angle pulse spectrum; Acquiring an actual value of a target air-fuel ratio of the hydrogen internal combustion engine, and querying a target air-fuel ratio value from an air-fuel ratio concentration map of the hydrogen internal combustion engine according to the transient factor; Determining the current hydrogen injection concentration in the hydrogen internal combustion engine according to the actual air-fuel ratio value and the target air-fuel ratio value; If the actual air-fuel ratio value is greater than the target air-fuel ratio value, it is determined that the current hydrogen injection concentration is too rich, a rich ignition advance angle map is selected as the target ignition advance angle map, and an ignition advance angle corresponding to the actual air-fuel ratio value is searched from the rich ignition advance angle map; If the actual air-fuel ratio value is less than the target air-fuel ratio value, it is determined that the current hydrogen injection concentration is lean, a lean ignition advance angle map is selected as the target ignition advance angle map, and the ignition advance angle corresponding to the actual air-fuel ratio value is queried from the lean ignition advance angle map.

3. A method for controlling a hydrogen internal combustion engine for improving transient response capability according to claim 2, characterized in that: The air-fuel ratio concentration map includes a rich map and a lean map, and selection of the air-fuel ratio concentration map is determined according to the transient factor.

4. A method for controlling a hydrogen internal combustion engine for improving transient response capability according to claim 3, characterized in that: When the value of the transient factor is 100%, the rich pulse spectrum is selected as the current air-fuel ratio concentration pulse spectrum; When the value of the transient factor is 0%, the lean map is selected as the current air-fuel ratio concentration map; When the value of the transient factor is other values, the rich pulse spectrum and the lean pulse spectrum are interpolated and selected to determine the target air-fuel ratio of the hydrogen internal combustion engine.

5. A method for controlling a hydrogen internal combustion engine for improving transient response capability according to claim 4, characterized in that: The target air-fuel ratio is determined as follows: According to the transient factor, a first air-fuel ratio is obtained from a rich pulse spectrum, and a second air-fuel ratio is obtained from a lean pulse spectrum, and the target air-fuel ratio is calculated by the following formula: α 目标 ＝α1·r+α2·(1-r)； Among them, α 目标 is the target air-fuel ratio, α1 is the first air-fuel ratio, α2 is the second air-fuel ratio, and r is the transient factor.

6. A method for controlling a hydrogen internal combustion engine for improving transient response capability according to claim 2, characterized in that: The ignition advance angle is optimized according to the actual air-fuel ratio value and the target air-fuel ratio value.

7. A method for controlling a hydrogen internal combustion engine for improving transient response capability according to claim 6, characterized in that: If it is determined that the current hydrogen injection concentration is too rich according to the actual air-fuel ratio value and the target air-fuel ratio value, a preset target step length is used as the increase basis of the ignition advance angle, and the ignition advance angle increases by one unit angle for each target step length difference between the actual air-fuel ratio value and the target air-fuel ratio value; If it is determined that the current hydrogen injection concentration is lean based on the actual air-fuel ratio value and the target air-fuel ratio value, the target step length is used as the basis for reducing the ignition advance angle. For every target step length difference between the actual air-fuel ratio value and the target air-fuel ratio value, the ignition advance angle is reduced by one unit angle.

8. A method for controlling a hydrogen internal combustion engine for improving transient response capability according to claim 7, characterized in that: The internal working condition of the hydrogen internal combustion engine is monitored, and if a signal of pre-ignition or knocking is detected in the hydrogen internal combustion engine, the optimization of the ignition advance angle is stopped.

9. A method for controlling a hydrogen internal combustion engine for improving transient response capability according to any one of claims 1 to 8, characterized in that: The transient factor is calculated by the following formula: Among them, r is the transient factor; P0 is the boost pressure target value of the hydrogen internal combustion engine; P1 is the actual boost pressure value of the hydrogen internal combustion engine; ΔP1 is the preset boost pressure high difference threshold; ΔP2 is the preset boost pressure low difference threshold.

10. A control system for implementing the method for controlling a hydrogen internal combustion engine for improving transient response capability as claimed in any one of claims 1 to 8, characterized in that: include: A power demand identification module, used to identify the current power demand of the hydrogen internal combustion engine; A transient factor calculation module, used to determine whether the current operating condition of the hydrogen internal combustion engine is a transient operating condition according to the current power demand of the hydrogen internal combustion engine, and if so, calculate the transient factor of the hydrogen internal combustion engine under the current operating condition; The transient enrichment and ignition advance angle control module is used to perform transient enrichment control on the air-fuel ratio and ignition advance angle of the hydrogen internal combustion engine according to the transient factor.

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