阅读说明：本技术 多次喷射燃油油量补偿方法、装置、电控单元及存储介质 (Multi-injection fuel quantity compensation method and device, electronic control unit and storage medium ) 是由 李明权 宋国梁 付文杰 王立国 于 2021-06-01 设计创作，主要内容包括：本发明实施例公开了一种多次喷射燃油油量补偿方法、装置、电控单元及存储介质。该补偿方法包括：获取共轨管设定轨压值和设定油量值；确定多次喷射燃油时喷射器的压力波动数学模型；根据所述压力波动数学模型确定第i+1喷射燃油时喷射器的压力值；其中,i为大于等于1的整数；根据所述共轨管设定轨压值及所述第i+1次喷射燃油喷射器的压力值确定轨压偏差；根据所述轨压偏差与所述设定油量值确定油量补偿量,以解决多次喷油引起的燃油压力波动的油量偏差问题,对实际的油量进行补偿,实现更好的燃油油量的控制效果。(The embodiment of the invention discloses a multi-injection fuel quantity compensation method, a multi-injection fuel quantity compensation device, an electronic control unit and a storage medium. The compensation method comprises the following steps: acquiring a set rail pressure value and a set oil mass value of the common rail pipe; determining a mathematical model of pressure fluctuations of the injector during multiple injections of fuel; determining the pressure value of an injector when the (i + 1) th fuel is injected according to the pressure fluctuation mathematical model; wherein i is an integer greater than or equal to 1; determining rail pressure deviation according to the set rail pressure value of the common rail pipe and the pressure value of the i +1 th fuel injection injector; and determining an oil quantity compensation quantity according to the rail pressure deviation and the set oil quantity value so as to solve the problem of oil quantity deviation of fuel pressure fluctuation caused by multiple times of oil injection, compensate the actual oil quantity and realize a better control effect of the fuel oil quantity.)

1. A multiple injection fuel quantity compensation method, comprising:

acquiring a set rail pressure value and a set oil mass value of the common rail pipe;

determining a mathematical model of pressure fluctuations of the injector during multiple injections of fuel;

determining the pressure value of an injector when the (i + 1) th fuel is injected according to the pressure fluctuation mathematical model; wherein i is an integer greater than or equal to 1;

determining rail pressure deviation according to the set rail pressure value of the common rail pipe and the pressure value of the i +1 th fuel injection injector;

and determining an oil quantity compensation quantity according to the rail pressure deviation and the set oil quantity value.

2. The multiple injection fuel quantity compensation method of claim 1, wherein determining a mathematical model of pressure fluctuation of the injector during multiple injections of fuel comprises:

determining an attenuation factor of the pressure fluctuation mathematical model according to the set rail pressure value of the common rail pipe and the power-on time of the injector;

determining a frequency factor of the pressure fluctuation mathematical model according to the fuel temperature and the bulk modulus of elasticity of the fuel;

determining an amplitude factor of the pressure fluctuation mathematical model according to the set rail pressure value of the common rail pipe and the power-on time of the injector;

and determining the pressure fluctuation function model according to the attenuation factor, the frequency factor and the amplitude factor.

3. The multiple injection fuel quantity compensation method according to claim 1, wherein the step of determining the pressure value of the fuel injector at the i +1 th fuel injection according to the pressure fluctuation mathematical model comprises the steps of:

determining the time for the ith fuel injection;

determining the time of the (i + 1) th fuel injection;

determining an injection time interval according to the time of the ith fuel injection and the time of the (i + 1) th fuel injection;

and determining the pressure value of the injector when the (i + 1) th fuel is injected according to the pressure fluctuation mathematical model and the injection time interval.

4. The multiple injection fuel quantity compensation method according to claim 2, characterized in that a decay factor of the pressure fluctuation mathematical model is determined based on the common rail set rail pressure value and the power-on time of the injector; the method specifically comprises the following steps:

k＝k(P_r，ET)

wherein, P_rSetting a rail pressure value for the common rail pipe; ET is the power-up time of the injector; k is the attenuation factor;

determining a frequency factor of the pressure fluctuation mathematical model according to the temperature of the fuel and the bulk modulus of elasticity of the fuel; the method specifically comprises the following steps:

w＝w(T，A)

wherein T is the fuel temperature; a is the bulk modulus of elasticity of the fuel oil; w is the frequency factor;

determining an amplitude factor of the pressure fluctuation mathematical model according to the set rail pressure value of the common rail pipe and the power-on time of the injector; the method specifically comprises the following steps:

f＝f(P_r，ET)

wherein, P_rSetting a rail pressure value for the common rail pipe; ET is the power-up time of the injector; f is an amplitude factor;

determining the pressure fluctuation function model according to the attenuation factor, the frequency factor and the amplitude factor; the method specifically comprises the following steps:

P_cor＝f(P_r，ET)e^-ktsin(wt+θ)

wherein, P_rSetting rail pressure for the common rail pipe; ET is the power-up time of the injector; w is a frequency factor of an oscillation of a pressure wave of the injector; θ is the phase offset; p_corIs the pressure fluctuation value of the ejector.

5. The multiple-injection fuel quantity compensation method according to claim 1, after determining the rail pressure deviation based on the common rail set rail pressure value and the pressure value of the i +1 th injection fuel injector, further comprising:

judging whether the rail pressure deviation is larger than a preset rail pressure deviation value or not;

when the rail pressure deviation is smaller than a preset rail pressure deviation value, determining an oil quantity compensation quantity according to the rail pressure deviation and the set oil quantity value;

and when the rail pressure deviation is larger than the preset rail pressure difference value, determining that the actual oil quantity value is the set oil quantity value.

6. The multiple-injection fuel quantity compensation method according to claim 5, further comprising, after determining the quantity compensation quantity based on the rail pressure deviation and the set fuel quantity value:

and determining the actual oil quantity value according to the oil quantity compensation quantity and the set oil quantity value.

7. The multiple injection fuel quantity compensation method according to claim 1, wherein obtaining the set fuel quantity value includes:

and determining a set oil quantity value according to the angle information of the injector and the oil injection time.

8. A multiple injection fuel quantity compensation device, characterized by comprising:

an acquisition module: the system is used for acquiring a set rail pressure value and a set oil mass value of the common rail pipe;

a fluctuating mathematical model determination module: a mathematical model for determining pressure fluctuations of the injector when injecting fuel multiple times;

a pressure value determination module: the pressure value of the injector when the (i + 1) th fuel is injected is determined according to the pressure fluctuation mathematical model; wherein i is an integer greater than or equal to 1;

a rail pressure differential determination module: the common rail pressure control device is used for determining rail pressure deviation according to the set rail pressure value of the common rail pipe and the pressure value of the injector during the fuel injection of the i +1 times;

the oil quantity compensation quantity determining module: and the oil quantity compensation quantity is determined according to the rail pressure deviation and the set oil quantity value.

9. An electronic control unit, comprising:

one or more processors;

a storage device for storing one or more programs,

when executed by the one or more processors, cause the one or more processors to implement a multiple injection fuel quantity compensation method as recited in any one of claims 1-7.

10. A computer-readable storage medium, on which a computer program is stored, which program, when being executed by a processor, carries out a multiple injection fuel quantity compensation method according to any one of claims 1 to 7.

Technical Field

The embodiment of the invention relates to a fuel control technology, in particular to a multi-injection fuel quantity compensation method, a multi-injection fuel quantity compensation device, an electronic control unit and a storage medium.

Background

The electric control high-pressure common rail system consists of a high-pressure oil pump, a common rail pipe, an oil injector, a sensor and an electronic control unit ECU. The electric control high-pressure common rail system is widely used, so that the combustion effect of the engine is greatly improved, the accurate control of the injection oil quantity is improved, and the emission and the comprehensive performance of the engine are greatly improved.

At present, in order to effectively improve the exhaust emission effect on the basis of ensuring the fuel economy of a diesel engine, multiple injections are adopted to replace single injection. When multiple injections are carried out, the former injection can cause the oil pipe at the end of the oil injector to generate pressure fluctuation, so that the actual pressure of the next injection is changed. Meanwhile, because the oil quantity is calculated based on the pressure, the difference between the actual pressure and the set pressure when the oil injector is released can be caused by the previous injection, and finally the deviation of the oil quantity is caused, so that the final control effect is poor, and certain influence is caused on the emission.

Disclosure of Invention

The invention provides a method and a device for compensating the fuel quantity of multiple fuel injections, an electric control unit and a storage medium, which are used for solving the problem of fuel quantity deviation of fuel pressure fluctuation caused by multiple fuel injections, compensating the actual fuel quantity and realizing a better control effect of the fuel quantity.

In a first aspect, an embodiment of the present invention provides a multiple injection fuel amount compensation method, where the compensation method includes:

acquiring a set rail pressure value and a set oil mass value of the common rail pipe;

determining a mathematical model of pressure fluctuations of the injector during multiple injections of fuel;

determining the pressure value of an injector when the (i + 1) th fuel is injected according to the pressure fluctuation mathematical model; wherein i is an integer greater than or equal to 1;

determining rail pressure deviation according to the set rail pressure value of the common rail pipe and the pressure value of the i +1 th fuel injection injector;

and determining an oil quantity compensation quantity according to the rail pressure deviation and the set oil quantity value.

Optionally, determining a mathematical model of pressure fluctuation of the injector over multiple injections of fuel comprises:

determining an attenuation factor of the pressure fluctuation mathematical model according to the set rail pressure value of the common rail pipe and the power-on time of the injector;

determining a frequency factor of the pressure fluctuation mathematical model according to the fuel temperature and the bulk modulus of elasticity of the fuel;

determining an amplitude factor of the pressure fluctuation mathematical model according to the set rail pressure value of the common rail pipe and the power-on time of the injector;

and determining the pressure fluctuation function model according to the attenuation factor, the frequency factor and the amplitude factor.

Optionally, determining a pressure value of the injector when the (i + 1) th fuel injection is performed according to the pressure fluctuation mathematical model includes:

determining the time for the ith fuel injection;

determining the time of the (i + 1) th fuel injection;

determining an injection time interval according to the time of the ith fuel injection and the time of the (i + 1) th fuel injection;

and determining the pressure value of the injector when the (i + 1) th fuel is injected according to the pressure fluctuation mathematical model and the injection time interval.

Optionally, determining an attenuation factor of the pressure fluctuation mathematical model according to the set rail pressure value of the common rail pipe and the power-on time of the injector; the method specifically comprises the following steps:

k＝k(P_r，ET)

wherein, P_rSetting a rail pressure value for the common rail pipe; ET is the power-up time of the injector; k is the attenuation factor;

determining a frequency factor of the pressure fluctuation mathematical model according to the temperature of the fuel and the bulk modulus of elasticity of the fuel; the method specifically comprises the following steps:

w＝w(T，A)

wherein T is the fuel temperature; a is the bulk modulus of elasticity of the fuel oil; w is the frequency factor;

determining an amplitude factor of the pressure fluctuation mathematical model according to the set rail pressure value of the common rail pipe and the power-on time of the injector; the method specifically comprises the following steps:

f＝f(P_r，ET)

wherein, P_rSetting a rail pressure value for the common rail pipe; ET is the power-up time of the injector; f is an amplitude factor;

determining the pressure fluctuation function model according to the attenuation factor, the frequency factor and the amplitude factor; the method specifically comprises the following steps:

P_cor＝f(P_r，ET)e^-ktsin(wt+θ)

wherein, P_rSetting rail pressure for the common rail pipe; ET is the power-up time of the injector; w is a frequency factor of an oscillation of a pressure wave of the injector; θ is the phase offset; p_corIs the pressure fluctuation value of the ejector.

Optionally, after determining the rail pressure deviation according to the set rail pressure value of the common rail pipe and the pressure value of the i +1 th injection fuel injector, the method further includes:

judging whether the rail pressure deviation is larger than a preset rail pressure deviation value or not;

when the rail pressure deviation is smaller than a preset rail pressure deviation value, determining an oil quantity compensation quantity according to the rail pressure deviation and the set oil quantity value;

and when the rail pressure deviation is larger than the preset rail pressure difference value, determining that the actual oil quantity value is the set oil quantity value.

Optionally, after determining the oil amount compensation amount according to the rail pressure deviation and the set oil amount value, the method further includes:

and determining an actual oil quantity value according to the oil quantity compensation quantity and the set oil quantity value.

Optionally, obtaining the set oil amount value includes:

and determining a set oil quantity value according to the angle information of the injector and the oil injection time.

In a second aspect, an embodiment of the present invention further provides a multiple injection fuel amount compensation device, including:

an acquisition module: the system is used for acquiring a set rail pressure value and a set oil mass value of the common rail pipe;

a fluctuating mathematical model determination module: a mathematical model for determining pressure fluctuations of the injector when injecting fuel multiple times;

a pressure value determination module: the pressure value of the injector when the (i + 1) th fuel is injected is determined according to the pressure fluctuation mathematical model; wherein i is an integer greater than or equal to 1;

a rail pressure differential determination module: the common rail pressure control device is used for determining rail pressure deviation according to the set rail pressure value of the common rail pipe and the pressure value of the injector during the fuel injection of the i +1 times;

the oil quantity compensation quantity determining module: and the oil quantity compensation quantity is determined according to the rail pressure deviation and the set oil quantity value.

In a third aspect, an embodiment of the present invention further provides an electronic control unit, including:

one or more processors;

a storage device for storing one or more programs,

when the one or more programs are executed by the one or more processors, the one or more processors may be caused to implement the multiple injection fuel amount compensation method according to the first aspect described above.

In a fourth aspect, the present invention further provides a computer-readable storage medium, on which a computer program is stored, which when executed by a processor implements the multi-injection fuel quantity compensation method according to the first aspect.

According to the embodiment of the invention, the set rail pressure value and the set oil mass value of the common rail pipe are obtained; determining a mathematical model of pressure fluctuations of the injector during multiple injections of fuel; determining the pressure value of the injector when the (i + 1) th fuel is injected according to the pressure fluctuation mathematical model; wherein i is an integer greater than or equal to 1; determining rail pressure deviation according to a set rail pressure value of the common rail pipe and a pressure value of the i +1 th fuel injection injector; and determining an oil quantity compensation quantity according to the rail pressure deviation and the set oil quantity value so as to solve the problem of oil quantity deviation of fuel pressure fluctuation caused by multiple times of oil injection, compensate the actual oil quantity and realize a better control effect of the fuel oil quantity.

Drawings

Fig. 1 is a flowchart of a multi-injection fuel quantity compensation method according to an embodiment of the present invention;

FIG. 2 is a flow chart illustrating a method for compensating for multiple injections of fuel according to an embodiment of the present invention;

FIG. 3 is a graphical representation of a mathematical model of injector pressure fluctuation during multiple injections of fuel, in accordance with an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a multiple injection fuel quantity compensation device according to a second embodiment of the present invention;

fig. 5 is a schematic structural diagram of an electronic control unit according to a third embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Example one

Fig. 1 is a flowchart of a multiple-injection fuel quantity compensation method according to an embodiment of the present invention, where the present embodiment is applicable to a multiple-injection fuel quantity compensation situation, and the method may be executed by a multiple-injection fuel quantity compensation device, and specifically includes the following steps:

s110, acquiring a set rail pressure value and a set oil mass value of the common rail pipe;

the diesel engine electric control high-pressure common rail system comprises a high-pressure oil pump, a common rail pipe, an injector, a sensor and an ECU. In order to effectively improve the exhaust emission effect on the basis of ensuring the fuel economy of the existing diesel engine, the injector is used for multiple injection instead of single injection. Because the single injection of fuel oil has little influence on the rail pressure in the common rail pipe, the rail pressure value of the common rail pipe is relatively stable and can be used as a reference voltage stabilizing source. In the actual multiple fuel injection process, a reference pressure stabilizing value of the common rail pipe during single fuel injection is obtained, namely a set rail pressure value of the common rail pipe is obtained, and a set fuel quantity value is obtained according to the injection angle information and the fuel injection time of each injector.

S120, determining a pressure fluctuation mathematical model of the injector during multiple fuel injection;

compared with the single-injection technology, when the injector performs multiple injections, the former injection of fuel can cause the oil pipe of the next injector to generate pressure fluctuation, so that the actual reference pressure of the next injection of fuel changes, and the fuel quantity of the next injection of fuel is calculated by referring to the actual reference pressure, so that the fuel quantity of the next injection of fuel also has certain deviation. According to the technical scheme, the pressure fluctuation mathematical model of the injector during multiple fuel injection can be established, so that the pressure fluctuation value of the injector during multiple fuel injection can be directly obtained, and the fuel quantity of the multiple fuel injection can be corrected according to the pressure fluctuation value during fuel injection.

It should be noted that after the injector is closed to inject fuel, a pressure wave is suddenly generated in the injector, the pressure in the pipeline of the injector is continuously increased, and when the pressure wave is propagated to the common rail pipe, the pressure in the pipeline of the injector is maximized; at this point, because of the imbalance of pressure in the common rail and injector lines, the unbalanced pressure creates a new pressure wave in the injector line that impinges on the valve between the common rail and injector lines, and the line pressure within the injector decreases until the pressure is at a minimum. Therefore, the process is repeated periodically, the pressure wave is reduced continuously, the frequency of the pressure wave is fixed, the amplitude of the pressure wave is reduced continuously, and based on the pressure wave, the pressure fluctuation mathematical model of the injector during multiple fuel injection is established by combining the pressure change condition of the injected fuel of the actual injector. Specifically, a mathematical model for determining injector pressure fluctuation during multiple injections of fuel is provided, comprising:

determining an attenuation factor of a pressure fluctuation mathematical model according to a set rail pressure value of a common rail pipe and the power-on time of an injector, specifically:

k＝k(P_r，ET)

wherein, P_rSetting a rail pressure value for the common rail pipe; ET is the time of energisation of the injector; k is an attenuation factor; thus, for the same type of high pressure common rail system, the attenuation factor k may be determined based on the power up time through the injector and the common rail set rail pressure value.

Determining a frequency factor of a pressure fluctuation mathematical model according to the temperature of the fuel oil and the volume elastic modulus of the fuel oil; the method specifically comprises the following steps:

w＝w(T，A)

wherein T is the fuel temperature; a is the bulk modulus of fuel oil; w is a frequency factor; when an actual injector injects oil, the main factors influencing the pressure fluctuation frequency of the injector are as follows: the cross section and length of a high-pressure oil pipe of the injector, the length and cross section of an internal oil path of the injector, the density and bulk modulus of elasticity of fuel, the volume of an internal pressure chamber of the injector and the volume of a common rail pipe. Besides the fuel density and the bulk modulus of elasticity, other parameters are fixed for a fixed high-pressure common rail system, wherein the direct influence factor of the fuel density rho is the fuel temperature T, and the influence of the bulk modulus of elasticity of the fuel on the fuel injection fluctuation is too small, so that the frequency factor w of the pressure fluctuation mathematical model can be determined through the fuel temperature T and the bulk modulus of elasticity A of the fuel.

Determining an amplitude factor of a pressure fluctuation mathematical model according to a set rail pressure value of the common rail pipe and the power-on time of the injector; the method specifically comprises the following steps:

f＝f(P_r，ET)

wherein, P_rSetting a rail pressure value for the common rail pipe; ET is the time of energisation of the injector; f is an amplitude factor; here, the amplitude factor f of the pressure wave of the injector and the set rail pressure value of the common rail can be approximately proportional: in addition, the amplitude factor f of the pressure wave of the injector becomes larger and eventually becomes smoother as the energization time ET increases. Therefore, the amplitude factor f can be determined by the amplitude factor of the mathematical model of pressure fluctuation determined by the common rail set rail pressure value and the power-up time of the injector.

Then determining a pressure fluctuation function model according to the attenuation factor k, the frequency factor w and the amplitude factor f; the method specifically comprises the following steps:

P_cor＝f(P_r，ET)e^-ktsin(wt+θ)

wherein, P_rSetting rail pressure for the common rail pipe; ET is the time of energisation of the injector; w is the frequency factor of the oscillation of the pressure wave of the injector; θ is the phase offset; p_corIs the pressure fluctuation value of the injector. FIG. 2 is a graphical representation of a mathematical model of injector pressure fluctuation during multiple injections of fuel, in accordance with an embodiment of the present invention. As shown in fig. 2, the model curve is established by the common rail set rail pressure, the power-on time of the injector, the fuel temperature and the bulk modulus, and the model curve can simulate the change situation that the pressure wave of the injected fuel of the actual injector is reduced continuously, the frequency of the pressure wave is fixed, and the amplitude of the pressure wave is reduced continuously.

S130, determining a pressure value of the injector when the (i + 1) th fuel is injected according to the pressure fluctuation mathematical model; wherein i is an integer greater than or equal to 1;

wherein, as shown in fig. 2, the abscissa of the mathematical model curve is the injection time interval; the ordinate is the pressure value of the injector; firstly, determining the time of fuel injection for the ith time, and then determining the time of fuel injection for the (i + 1) th time; determining an injection time interval according to the time of injecting fuel for the ith time and the time of injecting fuel for the (i + 1) th time; and substituting the injection time interval into the pressure fluctuation mathematical model, and finally determining the pressure value of the injector when the (i + 1) th injection fuel is injected according to the pressure fluctuation mathematical model and the injection time interval.

S140, determining rail pressure deviation according to a set rail pressure value of the common rail pipe and a pressure value of the i +1 th fuel injection injector;

and S150, determining an oil quantity compensation quantity according to the rail pressure deviation and the set oil quantity value.

The pressure value of the injector when the (i + 1) th fuel injection is carried out is obtained by substituting the injection time interval into a pressure fluctuation mathematical model, and then the rail pressure deviation value of the set rail pressure value of the common rail pipe and the pressure value of the (i + 1) th fuel injection injector is calculated; then regard this rail pressure deviation value and the product of setting for the oil mass value as the oil mass offset to revise actual oil mass, can realize more accurate oil mass correction effect, promote the controllability of automatically controlled common rail system, can the effectual burning that improves the engine.

Optionally, on the basis of the foregoing embodiment, fig. 3 is a flowchart of another method for compensating fuel quantity of multiple injections according to an embodiment of the present invention, and as shown in fig. 3, the method specifically includes the following steps:

s210, acquiring a set rail pressure value and a set oil mass value of the common rail pipe;

s220, determining a pressure fluctuation mathematical model of the injector during multiple fuel injection;

s230, determining the pressure value of the injector when the (i + 1) th fuel is injected according to the pressure fluctuation mathematical model; wherein i is an integer greater than or equal to 1;

s240, determining rail pressure deviation according to a set rail pressure value of the common rail pipe and a pressure value of the i +1 th fuel injection injector;

s250, judging whether the rail pressure deviation is larger than a preset rail pressure deviation value or not;

s260, when the rail pressure deviation is smaller than the preset rail pressure deviation value, determining an oil quantity compensation quantity according to the rail pressure deviation and a set oil quantity value;

s270, when the rail pressure deviation is larger than the preset rail pressure difference value, determining the actual oil quantity value as the set oil quantity value;

and S280, determining an actual oil quantity value according to the oil quantity compensation quantity and the set oil quantity value.

The rail pressure deviation value of the actual common rail pipe set rail pressure value and the pressure value of the (i + 1) th fuel injection injector exceeds the preset rail pressure deviation value, and the compensation quantity of the oil quantity compensation quantity determined by the rail pressure deviation and the set oil quantity value exceeds the preset range. According to the technical scheme, the pressure value of the injector when the (i + 1) th injector injects fuel is obtained through a pressure fluctuation mathematical model, the rail pressure deviation is determined according to the set rail pressure value of the common rail pipe and the pressure value of the (i + 1) th injector injecting fuel, whether the rail pressure deviation is greater than the preset rail pressure deviation value is judged, and when the rail pressure deviation is smaller than the preset rail pressure deviation value, the fuel quantity compensation quantity is determined according to the rail pressure deviation and the set fuel quantity value, so that the actual fuel quantity value is determined according to the fuel quantity compensation quantity and the set fuel quantity value, the excessive compensation of the fuel quantity is avoided, the effect of correcting the fuel quantity is improved, and the control output effect of the actual fuel quantity value is further improved; and when the rail pressure deviation is larger than the preset rail pressure difference value, the actual oil quantity value is not corrected, and the actual oil quantity value is the set oil quantity value.

Example two

The multi-injection fuel quantity compensation device provided by the second embodiment of the invention can execute the multi-injection fuel quantity compensation method provided by the first embodiment of the invention, and has corresponding functional modules and beneficial effects of the execution method. Fig. 4 is a schematic structural diagram of a multiple injection fuel quantity compensation device according to an embodiment of the present invention; as shown in fig. 4, the multiple injection fuel amount compensating device includes:

the acquisition module 10: the system is used for acquiring a set rail pressure value and a set oil mass value of the common rail pipe;

the fluctuation mathematical model determination module 20: a mathematical model for determining pressure fluctuations of the injector when injecting fuel multiple times;

pressure value determination module 30: the pressure value of the injector when the (i + 1) th fuel is injected is determined according to the pressure fluctuation mathematical model; wherein i is an integer greater than or equal to 1;

the rail pressure difference determination module 40: the system is used for determining the rail pressure deviation according to the set rail pressure value of the common rail pipe and the pressure value of the injector when the fuel is injected for i +1 times;

the oil amount compensation amount determination module 50: and the oil quantity compensation quantity is determined according to the rail pressure deviation and the set oil quantity value.

Optionally, the fluctuation mathematical model determination module 20 includes:

an attenuation factor determination unit: the attenuation factor of the pressure fluctuation mathematical model is determined according to the set rail pressure value of the common rail pipe and the power-on time of the injector;

a frequency factor determination unit: the frequency factor of the pressure fluctuation mathematical model is determined according to the fuel temperature and the bulk modulus of elasticity of the fuel;

a magnitude factor determination unit: the amplitude factor of the pressure fluctuation mathematical model is determined according to the set rail pressure value of the common rail pipe and the power-on time of the injector;

pressure fluctuation function model determination unit: and the pressure fluctuation function model is determined according to the attenuation factor, the frequency factor and the amplitude factor.

Optionally, the pressure value determining module 30 includes:

a first time determination unit: for determining the time for the ith fuel injection;

a second time determination unit: for determining the time for the (i + 1) th injection of fuel;

a time interval determination unit: for determining an injection time interval based on the time of the ith fuel injection and the time of the (i + 1) th fuel injection;

a pressure value determination unit: and the pressure value of the injector when the (i + 1) th fuel is injected is determined according to the pressure fluctuation mathematical model and the injection time interval.

Optionally, the attenuation factor determining unit is configured to:

k＝k(P_r，ET)

wherein, P_rSetting a rail pressure value for the common rail pipe; ET is the time of energisation of the injector; k is an attenuation factor;

a frequency factor determination unit, which functions as:

w＝w(T，A)

wherein T is the fuel temperature; a is the bulk modulus of fuel oil; w is a frequency factor;

a magnitude factor determination unit that functions to:

f＝f(P_r，ET)

wherein, P_rSetting a rail pressure value for the common rail pipe; ET is the time of energisation of the injector; f is an amplitude factor;

a pressure fluctuation function model determination unit; the function is as follows:

P_cor＝f(P_r，ET)e^-ktsin(wt+θ)

wherein, P_rSetting rail pressure for the common rail pipe; ET is the time of energisation of the injector; w is the frequency factor of the oscillation of the pressure wave of the injector; θ is the phase offset; p_corIs the pressure fluctuation value of the injector.

Optionally, the multiple injection fuel amount compensation device further includes:

the rail pressure deviation value judgment module: the device is used for judging whether the rail pressure deviation is larger than a preset rail pressure deviation value or not;

the oil quantity compensation quantity determining module: the method is particularly used for determining the oil quantity compensation quantity according to the rail pressure deviation and the set oil quantity value when the rail pressure deviation is smaller than the preset rail pressure deviation value.

Optionally, the multiple injection fuel amount compensation device further includes:

the actual oil quantity value determining module: the oil quantity compensation device is used for determining an actual oil quantity value according to the oil quantity compensation quantity and a set oil quantity value; and when the rail pressure deviation is larger than the preset rail pressure difference value, determining that the actual oil quantity value is the set oil quantity value.

Optionally, the obtaining module 10 includes:

set oil amount value determination unit: the oil injection device is used for determining the set oil quantity value according to the angle information of the injector and the oil injection time.

EXAMPLE III

Fig. 5 is a schematic structural diagram of an electronic control unit according to a third embodiment of the present invention, as shown in fig. 5, the electronic control unit includes a processor 70, a memory 71, an input device 72, and an output device 73; the number of the processors 70 in the electronic control unit can be one or more, and one processor 70 is taken as an example in fig. 5; the processor 70, the memory 71, the input device 72 and the output device 73 in the electronic control unit may be connected by a bus or other means, and the bus connection is exemplified in fig. 5.

The memory 71 is a computer-readable storage medium for storing software programs, computer-executable programs, and modules, such as program instructions corresponding to the multi-injection fuel amount compensation method according to the embodiment of the present invention. The processor 70 executes various functional applications of the electronic control unit and data processing by executing software programs, instructions and modules stored in the memory 71, that is, implements the multi-injection fuel quantity compensation method described above.

The memory 71 may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created according to the use of the terminal, and the like. Further, the memory 71 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device. In some examples, the memory 71 may further include a memory remotely located from the processor 70, and these remote memories may be connected to the electronic control unit via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The input device 72 may be used to receive input numeric or character information and to generate key signal inputs relating to user settings and function controls of the electronic control unit. The output device 73 may include a display device such as a display screen.

Example four

A fourth embodiment of the present invention further provides a storage medium containing computer-executable instructions, which when executed by a computer processor, perform a multiple injection fuel quantity compensation method, the method comprising:

acquiring a set rail pressure value and a set oil mass value of the common rail pipe;

determining a mathematical model of pressure fluctuations of the injector during multiple injections of fuel;

determining the pressure value of the injector when the (i + 1) th fuel is injected according to the pressure fluctuation mathematical model; wherein i is an integer greater than or equal to 1;

determining rail pressure deviation according to a set rail pressure value of the common rail pipe and the pressure value of the i +1 th fuel injection injector;

and determining the oil quantity compensation quantity according to the rail pressure deviation and the set oil quantity value.

Of course, the embodiment of the present invention provides a storage medium containing computer-executable instructions, and the computer-executable instructions are not limited to the operations of the method described above, and may also perform the operations related to the multiple injection fuel amount compensation method provided in any embodiment of the present invention.

From the above description of the embodiments, it is obvious for those skilled in the art that the present invention can be implemented by software and necessary general hardware, and certainly, can also be implemented by hardware, but the former is a better embodiment in many cases. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as a floppy disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a FLASH Memory (FLASH), a hard disk or an optical disk of a computer, and includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network device) to execute the methods according to the embodiments of the present invention.

It should be noted that, in the embodiment of the above search apparatus, each included unit and module are merely divided according to functional logic, but are not limited to the above division as long as the corresponding functions can be implemented; in addition, specific names of the functional units are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present invention.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.