CN106150737B - A method and device for compensating oil volume of multiple injections - Google Patents

Abstract

The present invention provides a kind of multi-injection oil mass compensation method and devices, when can solve engine operation under the injection mode repeatedly sprayed (more than twice), use the biggish problem of oil mass difference caused by existing oil mass oscillation compensation model compensation, each injection oil mass in engine operational cycle can be accurately compensated for, so that the target value that actual ejection oil mass gives close to ECU, to guarantee the stability of engine torque output and the emission performance of engine.The described method includes: determining the first amendment oil mass that i-th injection sprays the i-th+2 times and the second amendment oil mass that i+1 time injection sprays described the i-th+2 times, wherein, i takes 1 to all integers between N-2, and N is the injecting times of fuel injector in engine one action recycles；It is compensated according to the first amendment oil mass and the second amendment oil mass, the target oil mass sprayed described the i-th+2 times.The present invention is suitable for technical field of engine control.

Description

A method and device for compensating oil volume of multiple injections

technical field

The invention relates to the technical field of engine control, in particular to a method and device for compensating multiple injection fuel quantities.

Background technique

At present, in order to reduce the particles (Particulate Matter, PM) and nitrogen oxides (NO _x ) emitted by the engine, a multiple-injection fuel injection method has been introduced, that is, the fuel injected into the combustion chamber in one working cycle of the engine, from A shot is divided into two or more shots.

In order to ensure the power, economy and low emission requirements of the engine, it is necessary to precisely control the amount of fuel injected each time. However, when the previous injection is performed, the fuel outlet of the injector control chamber will be opened, and when the previous injection is completed, the fuel outlet of the fuel injector control chamber will be closed quickly, so that when connecting the fuel rail and the fuel injection Pressure waves will be generated in the high-pressure oil pipe of the injector and the high-pressure pipe in the injector body, so that the amount of fuel injected after the next time deviates from the target value given by the electronic control unit (Electronic Control Unit, ECU). Therefore, it is necessary to compensate the fuel quantity of the last injection so that the fuel quantity of the latter injection is close to the target value. In the prior art, based on the data of two adjacent injections before and after, the correlation analysis is carried out on the main factors affecting the fluctuation of oil quantity, so as to establish the compensation model of oil quantity fluctuation, and then the compensation is performed according to the fuel quantity fluctuation model. For more than two multiple injections, if only the influence of oil volume fluctuations between two adjacent injections is considered, on the one hand, the oil volume fluctuations between adjacent two injections may not have a clear regularity; on the other hand, There will also be mutual influence between two separate jets. Therefore, compensating the fuel quantity of the next injection according to the existing fuel quantity fluctuation compensation model will cause a large difference between the actual injected fuel quantity and the target fuel quantity.

Contents of the invention

In view of this, the present invention aims to propose a method for compensating the quantity of fuel injected multiple times, to at least solve the problem of using the existing fuel quantity fluctuation compensation model to compensate when the engine works under the fuel injection mode of multiple (more than two) injections. The problem caused by the large difference in oil quantity can accurately compensate the oil quantity of each injection in the engine working cycle, so that the actual injected oil quantity is close to the target value given by the ECU, so as to ensure the stability of the engine torque output and engine emission characteristics.

In order to achieve the above object, technical solution of the present invention is achieved in that way:

A multi-injection fuel quantity compensation method, comprising:

Determine the first corrected oil quantity of the i-th injection to the i+2-th injection and the second corrected oil quantity of the i+1-th injection to the i+2-th injection, wherein i ranges from 1 to N-2 All integers between, N is the number of injections of the injector in one working cycle of the engine;

According to the first corrected oil quantity and the second corrected oil quantity, the target oil quantity of the i+2th injection is compensated.

Further, before the determination of the first corrected oil quantity of the i-th injection to the i+2-th injection and the second corrected oil quantity of the i+1-th injection to the i+2-th injection, it also includes :

determining a first hydraulic delay time of the i-th injection, a second hydraulic delay time of the i+1-th injection, and,

According to the engine water temperature and the temperature value before the fuel oil passes through the fuel filter, the oil temperature influence coefficient is determined, and the oil temperature influence coefficient indicates the degree of influence of the fuel temperature on the fuel density and fuel pressure;

The determination of the first corrected oil quantity of the i-th injection to the i+2-th injection and the second corrected oil quantity of the i+1-th injection to the i+2-th injection includes:

According to the first hydraulic delay time, the oil temperature influence coefficient, the first target oil quantity of the i-th injection, and the first time interval between the i-th injection and the i+1-th injection, determining the first reference corrected oil quantity of the i-th injection to the i+2-th injection; and, according to the second hydraulic delay time, the oil temperature influence coefficient, the i+1-th injection The second target oil quantity, the second time interval between the i+1th injection and the i+2th injection, determine the i+1th injection versus the i+2th injection Two benchmarks to correct the oil quantity;

According to the first target oil quantity, determine a first correction coefficient, the first correction coefficient represents the influence coefficient of the oil quantity of the i-th injection on the i+2-th injection; and, according to the first correction coefficient The third target fuel quantity of i+2 injections and the common rail pressure of the i+1th injection determine a second correction coefficient, and the second correction coefficient represents the relationship between the third target fuel quantity and the ith +2 Influence coefficient of injection;

multiplying the first reference correction oil quantity by the first correction coefficient to obtain the first correction oil quantity; and multiplying the second reference correction oil quantity by the second correction coefficient to obtain The second correction oil quantity.

Further, the determination of the first hydraulic delay time of the i-th injection and the second hydraulic delay time of the i+1-th injection includes:

receiving a control instruction, and determining the first target oil quantity and the second target oil quantity according to the control instruction, wherein the control instruction includes the first target oil quantity and the second target oil quantity ;

Obtaining the common rail pressure of the i-th injection, and determining the first hydraulic delay according to the first target oil quantity, the common-rail pressure of the i-th injection, and the pre-stored first feature map table Time, wherein, the first characteristic Map table includes the corresponding relationship between oil quantity, common rail pressure and hydraulic delay time;

Obtaining the common rail pressure of the i+1th injection, and determining the Two hydraulic delay time.

Further, according to the first hydraulic pressure delay time, the oil temperature influence coefficient, the first target oil quantity of the i-th injection, the difference between the i-th injection and the i+1-th injection The first time interval is to determine the first reference correction oil quantity of the i-th injection to the i+2-th injection, including:

The first hydraulic delay time and the first time interval are added together to obtain a first influence time, and the first influence time represents the time period during which the i-th injection has an influence on the i+2-th injection ;

multiplying the oil temperature influence coefficient by the first influence time to obtain a first correction time;

According to the first target oil quantity, the first correction time, and the pre-stored second characteristic Map table, determine the first reference corrected oil quantity, wherein the second characteristic Map table includes oil quantity, correction time Corresponding relationship with benchmark corrected oil quantity;

According to the second hydraulic pressure delay time, the oil temperature influence coefficient, the second target oil quantity of the i+1 injection, the i+1 injection and the i+2 injection The second time interval for determining the i+1th injection to the i+2th injection's second reference corrected oil quantity includes:

Adding the second hydraulic delay time and the second time interval to obtain a second influence time, the second influence time indicates that the i+1th injection has an influence on the i+2th injection the duration of

multiplying the oil temperature influence coefficient by the second influence time to obtain a second correction time;

The second reference corrected oil quantity is determined according to the second target oil quantity, the second correction time, and the second characteristic Map table.

Further, the compensating the target oil quantity for the i+2th injection according to the first corrected oil quantity and the second corrected oil quantity includes:

adding the first corrected oil quantity and the second corrected oil quantity to obtain the compensated oil quantity;

If the compensation oil amount is greater than the first preset correction value and smaller than the second preset correction value, the third target oil amount is compensated according to the compensation oil amount.

In the prior art, for more than two multiple injections, only the influence of oil quantity fluctuation between two adjacent injections is considered. On the one hand, in more than two multiple injections, the oil volume fluctuation between two adjacent injections may not have a clear regularity; on the other hand, in more than two multiple injections, the two injections separated by also influence each other. Therefore, the fuel quantity fluctuation compensation model established only based on the data of two adjacent injections is not accurate, and then the fuel quantity of the next injection is compensated according to the fuel quantity fluctuation compensation model, which will make the actual injected fuel quantity and the target fuel quantity The difference between them is large. However, the multi-injection oil quantity compensation method described in the embodiment of the present invention not only considers the oil quantity fluctuation between two adjacent injections, but also considers the influence of the oil quantity fluctuation between two separate injections. Therefore, compared with the prior art method of compensating the subsequent injection only based on the oil quantity fluctuation compensation model established based on the data of two adjacent injections, the multi-injection fuel quantity compensation method described in the embodiment of the present invention can The oil quantity injected for each engine working cycle is compensated more accurately, so that the actual injected oil quantity is close to the target value given by the ECU, so as to ensure the stability of the engine torque output and the emission characteristics of the engine.

Another object of the present invention is to propose a multi-injection oil volume compensation device to at least solve the problem that the existing oil volume fluctuation compensation model is not accurate enough when the engine is working in a multiple (more than two) injection mode The resulting difference in oil quantity can accurately compensate the oil quantity injected each time in the engine working cycle, so that the actual injected oil quantity is close to the target value given by the ECU, thereby ensuring the stability of the engine torque output and the stability of the engine. emission characteristics.

In order to achieve the above object, technical solution of the present invention is achieved in that way:

A multi-injection oil volume compensation device, comprising: a corrected oil volume determination unit and a compensation unit;

The corrected oil quantity determination unit is used to determine the first corrected oil quantity of the i-th injection to the i+2-th injection and the second corrected oil quantity of the i+1-th injection to the i+2-th injection , wherein, i takes all integers between 1 and N-2, and N is the number of injections of the fuel injector in one working cycle of the engine;

The compensation unit is configured to compensate the target oil amount of the i+2th injection according to the first corrected oil amount and the second corrected oil amount.

Further, the device further includes: a hydraulic delay time determination unit, an oil temperature influence coefficient determination unit;

The hydraulic delay time determination unit is used to determine the first correction oil quantity of the i-th injection to the i+2-th injection and the i+1-th injection to the i+2-th injection in the correction oil quantity determination unit Before the second corrected oil quantity of the injection, determine the first hydraulic delay time of the i-th injection and the second hydraulic delay time of the i+1-th injection;

The oil temperature influence coefficient determination unit determines the oil temperature influence coefficient according to the engine water temperature and the temperature value before the fuel passes through the fuel filter, and the oil temperature influence coefficient indicates the degree of influence of fuel temperature on fuel density and fuel pressure;

The corrected oil volume determination unit specifically includes: a benchmark corrected oil volume determination module, a correction coefficient determination module, and a corrected oil volume calculation module;

The reference corrected oil quantity determination module is configured to determine the first hydraulic pressure delay time, the oil temperature influence coefficient, the first target oil quantity of the i-th injection, the i-th injection and the In the first time interval of the i+1 injection, determine the first reference corrected oil quantity of the i-th injection to the i+2-th injection; and, according to the second hydraulic delay time, the oil temperature influence coefficient, the second target oil quantity of the i+1 injection, and the second time interval between the i+1 injection and the i+2 injection, determine the i+1 injection The second reference corrected oil quantity for the i+2th injection;

The correction coefficient determination module is configured to determine a first correction coefficient according to the first target oil quantity, and the first correction coefficient represents the oil quantity of the i-th injection to the i+2-th injection influence coefficient; and, according to the third target oil quantity of the i+2th injection and the common rail pressure of the i+1th injection, determine a second correction coefficient, the second correction coefficient represents the The influence coefficient of the three-target oil quantity on the i+2 injection;

The corrected oil volume calculation module is configured to multiply the first reference corrected oil volume by the first correction coefficient to obtain the first corrected oil volume; The second correction coefficient is multiplied to obtain the second correction oil amount.

Further, the hydraulic delay time determination unit specifically includes: a control instruction receiving module, a target oil volume determination module, a common rail pressure acquisition module, and a hydraulic delay time determination module;

The control instruction receiving module is configured to receive a control instruction, wherein the control instruction includes the first target oil quantity and the second target oil quantity;

The target oil quantity determination module is configured to determine the first target oil quantity and the second target oil quantity according to the control instruction;

The common rail pressure obtaining module is used to obtain the common rail pressure of the i-th injection;

The hydraulic delay time determination module is configured to determine the first hydraulic delay time according to the first target oil quantity, the common rail pressure of the i-th injection, and a pre-stored first feature map table, wherein , the first feature Map table includes the corresponding relationship between oil quantity, common rail pressure and hydraulic delay time;

The common rail pressure obtaining module is also used to obtain the common rail pressure of the i+1th injection;

The hydraulic delay time determining module is further configured to determine the second hydraulic delay time according to the second target oil quantity, the common rail pressure of the (i+1)th injection, and the first characteristic Map table .

Further, the reference correction oil quantity determination module is specifically used for:

The first hydraulic delay time and the first time interval are added together to obtain a first influence time, and the first influence time represents the time period during which the i-th injection has an influence on the i+2-th injection ;

multiplying the oil temperature influence coefficient by the first influence time to obtain a first correction time;

According to the first target oil quantity, the first correction time, and the pre-stored second characteristic Map table, determine the first reference corrected oil quantity, wherein the second characteristic Map table includes oil quantity, correction time Corresponding relationship with benchmark corrected oil quantity;

The reference correction oil quantity determination module is also specifically used for:

Adding the second hydraulic delay time and the second time interval to obtain a second influence time, the second influence time indicates that the i+1th injection has an influence on the i+2th injection the duration of

multiplying the oil temperature influence coefficient by the second influence time to obtain a second correction time;

The second reference corrected oil quantity is determined according to the second target oil quantity, the second correction time, and the second characteristic Map table.

Further, the compensation unit specifically includes: a compensation oil calculation module and a compensation module;

The compensation oil amount calculation module is used to add the first corrected oil amount and the second corrected oil amount to obtain the compensated oil amount;

The compensation module is configured to compensate the third target oil amount according to the compensation oil amount if the compensation oil amount is greater than a first preset correction value and smaller than a second preset correction value.

The multiple-injection oil quantity compensation device has the same advantages as the above-mentioned multiple-injection oil quantity compensation method over the prior art, and will not be repeated here.

Description of drawings

The drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention. In the attached picture:

Figure 1 is a structural diagram of the high pressure common rail fuel system;

Fig. 2 is a schematic flow diagram of the method for compensating the amount of fuel for multiple injections according to the embodiment of the present invention;

Fig. 3 is a schematic diagram of the application of the multi-injection fuel quantity compensation method in the embodiment of the present invention to three injections;

Fig. 4 is a schematic diagram of the application of the multi-injection fuel quantity compensation method in the embodiment of the present invention to four injections;

Fig. 5 is the second schematic flow diagram of the multi-injection oil volume compensation method according to the embodiment of the present invention;

Fig. 6 is a Map diagram of oil quantity, reference correction oil quantity and correction time;

Fig. 7 is the third schematic flow diagram of the multi-injection fuel quantity compensation method according to the embodiment of the present invention;

Fig. 8 is the fourth schematic flow diagram of the multi-injection fuel quantity compensation method according to the embodiment of the present invention;

Fig. 9 is a schematic diagram of the principles of the multi-injection oil quantity compensation method according to the embodiment of the present invention;

Fig. 10 is a structural schematic diagram of a multi-injection oil quantity compensation device according to an embodiment of the present invention;

Fig. 11 is a structural schematic diagram II of the multi-injection oil quantity compensation device according to the embodiment of the present invention;

Fig. 12 is a structural schematic diagram III of the multi-injection oil quantity compensation device according to the embodiment of the present invention;

Fig. 13 is a fourth schematic diagram of the structure of the multi-injection oil quantity compensating device according to the embodiment of the present invention.

Explanation of reference signs:

1-Fuel tank, 2-Fuel filter, 3-High pressure oil pump, 4-Drain valve, 5-High pressure oil pipe, 6-Common rail pipe, 7-Pressure sensor, 8-Injector, 9-ECU, 10- sensor.

Detailed ways

It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

In addition, in order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, words such as "first" and "second" are used to distinguish the same or similar items with basically the same function and effect, Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order.

The present invention will be described in detail below with reference to the accompanying drawings and examples.

In order to facilitate the understanding of the present invention, first, in combination with the structural diagram of the high-pressure common rail fuel system shown in Figure 1, the working principle of the engine fuel system is briefly introduced as follows:

As shown in Figure 1, the fuel in the fuel tank 1 in the figure is sucked into the fuel filter 2, and a part of the fuel is pressurized in the plunger chamber of the high-pressure fuel pump 3 to form high-pressure fuel, which flows from the outlet valve of the high-pressure fuel pump 3 The high-pressure fuel pipe 5 is collected into the common rail pipe 6 to provide a stable and continuous high-pressure fuel source for the high-pressure injection of the fuel injector 8, and a part of the excess fuel is returned from the overflow valve of the high-pressure fuel pump 3 and the fuel injector 8. flow back to the fuel tank 1 together; the high-pressure fuel flows from the common rail pipe 6 through the high-pressure fuel pipe 5 to the fuel injector 8 of each cylinder of the engine; the fuel injector 8 injects the fuel into each in the combustion chamber of the cylinder. One end of the common rail pipe 6 is equipped with a fuel pressure sensor 7, which can monitor the fuel pressure in the common rail pipe 6 in real time. When the fuel pressure exceeds the allowable maximum value, the oil drain valve 4 is opened, and the fuel pressure in the common rail pipe drops rapidly to within the security range to ensure the security of the entire system. The ECU9 collects the state parameters of the engine and the common rail system detected by each sensor 10 in real time, sends out accurate current pulse signals through the control strategy and stored data, and makes the corresponding common rail pump solenoid valves, fuel injector solenoid valves, etc. generate electromagnetic force, To drive the corresponding actuator to act, adjust the fuel supply, common rail pressure, fuel injection angle and fuel injection volume, etc., so that the engine calibration works.

FIG. 2 is a schematic flow chart of a method for compensating fuel quantity for multiple injections provided by an embodiment of the present invention. Referring to Figure 2, the method includes:

S201. The multi-injection fuel volume compensation device determines a first corrected fuel volume of the i-th injection to the i+2-th injection and a second corrected fuel volume of the i+1-th injection to the i+2-th injection.

Wherein, i takes all integers between 1 and N-2, and N is the number of injections of the fuel injector in one working cycle of the engine.

S202. The multi-injection fuel quantity compensation device compensates the target fuel quantity of the i+2th injection according to the first corrected fuel quantity and the second corrected fuel quantity.

It should be noted that, for three injections, as shown in Figure 3, the multi-injection fuel quantity compensation method in the embodiment of the present invention only needs to consider the influence of the first injection and the second injection on the third injection, so In one working cycle of the engine, only the target oil quantity of the third injection can be compensated; for more than three multiple injections, oil quantity compensation needs to be performed for every three adjacent injections, for example, for four injections, It is necessary to consider the influence of the first injection and the second injection on the third injection, and the influence of the second injection and the third injection on the fourth injection, as shown in Figure 4. Therefore, for four injections, it is necessary to compensate the target oil quantities of the third injection and the fourth injection respectively.

It can be seen from the above that for more than two multiple injections, the multi-injection oil volume compensation method described in the embodiment of the present invention not only takes into account the oil volume fluctuation between two adjacent injections, but also takes into account the two injections that are separated. Influenced by fluctuations in oil quantity. Therefore, compared with the prior art method of compensating the subsequent injection only based on the oil quantity fluctuation compensation model established based on the data of two adjacent injections, the multi-injection fuel quantity compensation method described in the embodiment of the present invention can The oil quantity injected for each engine working cycle is compensated more accurately, so that the actual injected oil quantity is close to the target value given by the ECU, so as to ensure the stability of the engine torque output and the emission characteristics of the engine.

Preferably, as shown in Figure 5, in the multi-injection oil quantity compensation method provided by the embodiment of the present invention, the first corrected oil quantity of the i-th injection to the i+2-th injection is determined in the multi-injection oil quantity compensation device And before the second corrected oil quantity of the i+1 injection to the i+2 injection, it may also include:

S203. The multi-injection oil quantity compensation device determines the first hydraulic delay time of the i-th injection and the second hydraulic pressure delay time of the i+1-th injection.

It should be noted that due to the influence of the structural characteristics of the injector, there will be a certain delay between the opening and closing time of each injection. The impact of fluctuations is taken into account.

S204. The multi-injection fuel quantity compensation device determines the oil temperature influence coefficient according to the engine water temperature and the temperature value of the fuel before passing through the fuel filter.

Among them, the influence coefficient of oil temperature indicates the influence degree of fuel temperature on fuel density and fuel pressure.

It should be noted that the fuel temperature will affect the fuel density and fuel pressure, and the fuel density and fuel pressure will affect the fuel injection quantity. Therefore, the influence of the fuel temperature needs to be taken into consideration, but based on the existing technology, it is difficult to directly obtain the temperature of the fuel entering the injector. Therefore, the multi-injection fuel quantity compensation method provided by the embodiment of the present invention, by comprehensively considering the influence of the water temperature of the engine and the temperature value before the fuel filter (that is, the oil temperature before the fuel filter) on the fuel density and fuel pressure, indirectly The effect of fuel temperature on fuel density and fuel pressure is obtained to take into account the effect of fuel temperature on fluctuations in injected fuel volume.

Specifically, the engine water temperature, the fuel temperature before passing through the fuel filter, and the dynamic change of the actual injected fuel volume can be monitored through the bench test in advance to obtain the change relationship among the three, and then determine the engine water temperature and the fuel flow rate according to the change relationship. The corresponding relationship between the temperature value before the fuel filter and the oil temperature influence coefficient, and store the corresponding relationship. When executing the method of the present invention, the temperature sensor measures the engine water temperature and the temperature value of the fuel before passing through the fuel filter, and then obtains the oil temperature influence coefficient according to the stored corresponding relationship. This embodiment of the present invention does not specifically limit it.

The multi-injection fuel volume compensation device determines the first corrected fuel volume of the i-th injection to the i+2-th injection and the second corrected fuel volume of the i+1-th injection to the i+2-th injection (ie S201), Specifically can include:

S201a. The multi-injection oil volume compensator determines according to the first hydraulic pressure delay time, the oil temperature influence coefficient, the first target oil volume of the i-th injection, and the first time interval between the i-th injection and the i+1-th injection The i-th injection corresponds to the first reference oil quantity of the i+2 injection; and, according to the second hydraulic delay time, the oil temperature influence coefficient, the second target oil quantity of the i+1 injection, the i+1 The second time interval between the first injection and the (i+2)th injection determines the second reference corrected oil quantity of the (i+1)th injection to the (i+2)th injection.

S201b. The multi-injection fuel quantity compensator determines the first correction coefficient according to the first target fuel quantity; and, according to the third target fuel quantity of the i+2 injection and the common rail pressure of the i+1 injection, determine Second correction factor.

Wherein, the first correction coefficient represents the influence coefficient of the i-th injection fuel quantity on the i+2 injection, and the second correction coefficient represents the influence coefficient of the third target fuel quantity on the i+2 injection.

S201c. The multi-injection fuel quantity compensator multiplies the first reference corrected fuel quantity by the first correction coefficient to obtain the first corrected fuel quantity; and multiplies the second standard corrected fuel quantity by the second correction coefficient to obtain the second correction coefficient. 2. Correct the oil quantity.

Preferably, in step S201a, the multi-injection oil quantity compensator is based on the first hydraulic delay time, the oil temperature influence coefficient, the first target oil quantity of the i-th injection, the i-th injection and the i+1-th injection For a time interval, determine the first reference corrected oil quantity for the i-th injection to the i+2-th injection, which may specifically include:

The multi-injection fuel quantity compensation device adds the first hydraulic delay time and the first time interval to obtain the first influence time, and the first influence time represents the duration of the influence of the i-th injection on the i+2-th injection;

The multi-injection oil quantity compensation device multiplies the oil temperature influence coefficient by the first influence time to obtain the first correction time;

The multi-injection fuel quantity compensation device determines the first reference corrected fuel quantity according to the first target fuel quantity, the first correction time, and the pre-stored second characteristic Map table.

Wherein, the second characteristic Map table includes the corresponding relationship between the oil quantity, the correction time and the reference corrected oil quantity. The second characteristic Map table can be specifically obtained through the Map diagram (see Figure 6) between the oil volume, the correction time and the reference correction oil volume. Specific limits.

Similarly, the multi-injection oil quantity compensation device is based on the second hydraulic delay time, the oil temperature influence coefficient, the second target oil quantity of the i+1 injection, the i+1 injection and the i+2 injection The second time interval is to determine the second reference correction oil quantity for the i+1 injection to the i+2 injection, which may specifically include:

The multi-injection oil quantity compensation device adds the second hydraulic delay time and the second time interval to obtain the second influence time, and the second influence time represents the duration of the influence of the i+1 injection on the i+2 injection;

The multi-injection oil volume compensation device multiplies the oil temperature influence coefficient by the second influence time to obtain the second correction time;

The multi-injection fuel quantity compensation device determines a second reference corrected fuel quantity according to the second target fuel quantity, the second correction time, and the second characteristic Map table.

Preferably, in step S201b, the multi-injection fuel quantity compensation device determines the first correction coefficient according to the first target fuel quantity, which may specifically include:

The multi-injection oil quantity compensation device determines the first correction coefficient according to the first target oil quantity and the corresponding relationship between the pre-stored oil quantity and the first correction coefficient.

The multi-injection fuel quantity compensation device determines the second correction coefficient according to the third target fuel quantity of the i+2 injection and the common rail pressure of the i+1 injection, which may specifically include:

The multi-injection oil quantity compensation device determines the second correction coefficient according to the third target oil quantity, the common rail pressure of the i+1th injection, and the pre-stored third characteristic Map table.

Wherein, the third characteristic Map table includes the corresponding relationship between the oil quantity, the common rail pressure and the second correction coefficient.

In addition, it should be noted that the corresponding relationship between the oil quantity and the first correction coefficient can be a linear or non-linear functional relationship between the oil quantity and the first correction coefficient, and can be obtained through bench experiments in advance, and the specific process is the same as the aforementioned The process of determining the influence coefficient of oil temperature is similar and will not be repeated here.

Preferably, as shown in Figure 7, in the multi-injection oil quantity compensation method provided by the embodiment of the present invention, the multi-injection oil quantity compensation device determines the first hydraulic delay time of the i-th injection, the first hydraulic delay time of the i+1-th injection The second hydraulic pressure delay time (that is, S203) may specifically include:

S203a. The multi-injection fuel quantity compensator receives the control command, and determines the first target fuel quantity and the second target fuel quantity according to the control command, wherein the control command includes the first target fuel quantity and the second target fuel quantity.

S203b. The multi-injection oil volume compensator acquires the common rail pressure of the i-th injection, and determines the first hydraulic delay according to the first target oil volume, the common-rail pressure of the i-th injection, and the pre-stored first characteristic Map table time.

Wherein, the first characteristic Map table includes the corresponding relationship between oil quantity, common rail pressure and hydraulic delay time.

S203c. The multi-injection fuel quantity compensation device acquires the common rail pressure of the i+1 injection, and determines the second Hydraulic delay time.

Specifically, as shown in Fig. 8, in the multi-injection fuel quantity compensation method provided by the embodiment of the present invention, the multiple-injection fuel quantity compensator is based on the first corrected oil quantity and the second corrected oil quantity, Compensate the target oil quantity injected (ie S202), which may specifically include:

S202a. The multi-injection fuel quantity compensation device adds the first corrected fuel quantity and the second corrected fuel quantity to obtain the compensated fuel quantity.

S202b. If the compensation oil amount is greater than the first preset correction value and smaller than the second preset correction value, the multi-injection oil amount compensation device compensates the third target oil amount according to the compensation oil amount.

Wherein, the first preset correction value is the maximum correction value allowed by the system, the second preset correction value is the minimum correction value allowed by the system, and the first preset correction value and the second preset correction value can be based on experience obtained, which is not specifically limited in the embodiments of the present invention.

In this way, when the system breaks down or the parameters obtained by the compensation device are incorrect, which leads to an error in the final calculated compensation oil quantity, the wrong compensation can be avoided and the safety of the system can be ensured.

Exemplarily, in combination with the above-mentioned specific implementation, a specific example of using the multi-injection oil quantity compensation method provided by the embodiment of the present invention to perform oil quantity compensation is given as follows (the principle is shown in FIG. 9 ):

S1. Acquire the first time interval, the first target oil quantity, the first common rail pressure, the second time interval, the second target oil quantity, the second common rail pressure, and the third target oil quantity according to the control instruction; according to the temperature Sensors to obtain engine water temperature and oil temperature before fuel filter.

S2. Determine a first hydraulic delay time according to the first target oil quantity, the first common rail pressure, and the first characteristic Map, and add the first hydraulic delay time to the first time interval to obtain a first influence time.

S3. Determine a second hydraulic delay time according to the second target oil quantity, the second common rail pressure, and the second characteristic Map, and add the second hydraulic delay time to the second time interval to obtain a second influence time.

S4. Determine the oil temperature influence coefficient according to the engine water temperature and the oil temperature before the fuel filter.

S5. Multiply the oil temperature influence coefficient by the first influence time and the second influence time respectively to obtain a first correction time and a second correction time.

S6. Determine a first reference corrected oil amount according to the first correction time, the first target oil amount, and the second characteristic Map table.

S7. Determine a second reference corrected oil amount according to the second correction time, the second target oil amount, and the second characteristic Map table.

S8. Determine a first correction coefficient according to the first target oil quantity.

S9. Determine a second correction coefficient according to the third target oil quantity, the second common rail pressure, and the third characteristic Map table.

S10. Multiply the first reference correction oil quantity by the first correction coefficient to obtain the first correction oil quantity.

S11. Multiply the second reference correction oil quantity by the second correction coefficient to obtain a second correction oil quantity.

S12. Add the first corrected oil amount and the second corrected oil amount to obtain the compensated oil amount.

S13. If the compensation oil amount is greater than the first preset correction value and smaller than the second preset correction value, compensate the third target oil amount according to the compensation oil amount.

At this point, the oil quantity compensation is over. Of course, the above example is only a preferred embodiment given by the embodiment of the present invention, and the present invention is not limited thereto.

In the prior art, for more than two multiple injections, only the influence of oil quantity fluctuation between two adjacent injections is considered. On the one hand, in more than two multiple injections, the oil volume fluctuation between two adjacent injections may not have a clear regularity; on the other hand, in more than two multiple injections, the two injections separated by also influence each other. Therefore, the fuel quantity fluctuation compensation model established only based on the data of two adjacent injections is not accurate, and then the fuel quantity of the next injection is compensated according to the fuel quantity fluctuation compensation model, which will make the actual injected fuel quantity and the target fuel quantity The difference between them is large. However, the multi-injection oil quantity compensation method described in the embodiment of the present invention not only considers the oil quantity fluctuation between two adjacent injections, but also considers the influence of the oil quantity fluctuation between two separate injections. Therefore, compared with the prior art method of compensating the subsequent injection only based on the oil quantity fluctuation compensation model established based on the data of two adjacent injections, the multi-injection fuel quantity compensation method described in the embodiment of the present invention can The oil quantity injected for each engine working cycle is compensated more accurately, so that the actual injected oil quantity is close to the target value given by the ECU, so as to ensure the stability of the engine torque output and the emission characteristics of the engine.

FIG. 10 is a schematic structural diagram of a multi-injection fuel quantity compensation device 100 provided by an embodiment of the present invention, including: a corrected fuel quantity determination unit 1001 and a compensation unit 1002 .

Wherein, the corrected oil amount determination unit 1001 is used to determine the first corrected oil amount of the i-th injection to the i+2-th injection and the second corrected oil amount of the i+1-th injection to the i+2-th injection.

Wherein, i takes all integers between 1 and N-2, and N is the number of injections of the fuel injector in one working cycle of the engine.

The compensation unit 1002 is configured to compensate the target oil quantity of the i+2th injection according to the first corrected oil quantity and the second corrected oil quantity.

Further, as shown in FIG. 11 , the multi-injection oil quantity compensation device 100 according to the embodiment of the present invention may further include: a hydraulic delay time determination unit 1003 , and an oil temperature influence coefficient determination unit 1004 .

Among them, the hydraulic delay time determination unit 1003 is used to determine the first corrected oil quantity of the i-th injection versus the i+2-th injection and the i+1-th injection versus the i+2-th injection in the correction oil amount determination unit 1001 Before the second corrected oil quantity, determine the first hydraulic delay time of the i-th injection and the second hydraulic delay time of the i+1-th injection;

The oil temperature influence coefficient determining unit 1004 determines the oil temperature influence coefficient according to the engine water temperature and the temperature value of the fuel before passing through the fuel filter. The oil temperature influence coefficient indicates the degree of influence of the fuel temperature on the fuel density and fuel pressure.

Then, the corrected oil volume determination unit 1001 may specifically include: a reference corrected oil volume determination module 1001a, a correction coefficient determination module 1001b, and a corrected oil volume calculation module 1001c.

Wherein, the reference corrected oil amount determination module 1001a is used to determine the first hydraulic pressure delay time, the oil temperature influence coefficient, the first target oil amount of the i-th injection, the first time of the i-th injection and the i+1th injection interval, determine the first reference corrected oil quantity for the i-th injection to the i+2-th injection; and, according to the second hydraulic delay time, oil temperature influence coefficient, the second target oil quantity for the i+1-th injection, the The second time interval between the i+1 injection and the i+2 injection determines the second reference corrected oil quantity for the i+1 injection to the i+2 injection;

The correction coefficient determination module 1001b is configured to determine a first correction coefficient according to the first target oil quantity, and the first correction coefficient represents the influence coefficient of the i+2 injection on the i+2 injection; and, according to the i+2 Determine the second correction coefficient for the third target oil quantity of the 2 injections and the common rail pressure of the i+1 injection, and the second correction coefficient represents the influence coefficient of the third target oil quantity on the i+2 injection;

The corrected oil quantity calculation module 1001c is used to multiply the first standard corrected oil quantity by the first correction coefficient to obtain the first corrected oil quantity; and multiply the second standard corrected oil quantity by the second correction coefficient to obtain the first 2. Correct the oil quantity.

Further, as shown in FIG. 12 , in the multi-injection oil volume compensation device 100 according to the embodiment of the present invention, the hydraulic delay time determination unit 1003 specifically includes: a control instruction receiving module 1003a, a target oil volume determination module 1003b, a common rail The pressure acquisition module 1003c, the hydraulic pressure delay time determination module 1003d.

A control command receiving module 1003a, configured to receive a control command, wherein the control command includes a first target oil volume and a second target oil volume;

The target oil quantity determination module 1003b is used to determine the first target oil quantity and the second target oil quantity according to the control instruction;

A common rail pressure acquisition module 1003c, configured to acquire the common rail pressure of the i-th injection;

The hydraulic delay time determination module 1003d is configured to determine the first hydraulic delay time according to the first target oil quantity, the common rail pressure of the i-th injection, and the pre-stored first feature map table, wherein the first feature map table includes Corresponding relationship between oil quantity, common rail pressure and hydraulic delay time;

The common rail pressure obtaining module 1003c is also used to obtain the common rail pressure of the i+1th injection;

The hydraulic delay time determining module 1003d is further configured to determine a second hydraulic delay time according to the second target oil quantity, the common rail pressure of the (i+1)th injection, and the first characteristic Map table.

Preferably, the reference correction oil quantity determination module 1001a is specifically used for:

Add the first hydraulic delay time and the first time interval to obtain the first influence time, and the first influence time represents the duration of the influence of the i-th injection on the i+2-th injection;

Multiply the oil temperature influence coefficient by the first influence time to obtain the first correction time;

According to the first target oil quantity, the first correction time, and the pre-stored second characteristic Map table, determine the first reference correction oil quantity, wherein the second characteristic Map table includes the corresponding relationship between the oil quantity, correction time and the reference correction oil quantity .

The reference correction oil quantity determination module 1001a is also specifically used for:

Add the second hydraulic delay time and the second time interval to obtain the second influence time, and the second influence time represents the duration of the influence of the i+1 injection on the i+2 injection;

Multiply the oil temperature influence coefficient by the second influence time to obtain the second correction time;

According to the second target oil quantity, the second correction time, and the second characteristic Map table, a second reference corrected oil quantity is determined.

Preferably, the correction coefficient determination module 1001b is specifically used for:

Determine the first correction coefficient according to the first target oil quantity and the corresponding relationship between the pre-stored oil quantity and the first correction coefficient;

The correction coefficient determination module 1001b is also specifically used for:

According to the third target oil quantity, the common rail pressure of the i+1th injection, and the pre-stored third characteristic Map table, the second correction coefficient is determined, wherein the third characteristic Map table includes the oil quantity, the common rail pressure and the second Correspondence of correction coefficients.

Further, as shown in FIG. 13 , in the multi-injection fuel volume compensation device 100 according to the embodiment of the present invention, the compensation unit 1002 specifically includes: a compensation fuel volume calculation module 1002a and a compensation module 1002b.

Wherein, the compensation oil amount calculation module 1002a is used to add the first correction oil amount and the second correction oil amount to obtain the compensation oil amount.

The compensation module 1002b is configured to compensate the third target oil quantity according to the compensated oil quantity if the compensated oil quantity is greater than the first preset correction value and smaller than the second preset correction value.

Specifically, the method for compensating the target oil quantity by using the multi-injection oil quantity compensating device 100 provided by the embodiment of the present invention may refer to the above-mentioned relevant description of the embodiment of the present invention, and details are not repeated here.

In the prior art, for more than two multiple injections, only the influence of oil quantity fluctuation between two adjacent injections is considered. On the one hand, in more than two multiple injections, the oil volume fluctuation between two adjacent injections may not have a clear regularity; on the other hand, in more than two multiple injections, the two injections separated by also influence each other. Therefore, the fuel quantity fluctuation compensation model established only based on the data of two adjacent injections is not accurate, and then the fuel quantity of the next injection is compensated according to the fuel quantity fluctuation compensation model, which will make the actual injected fuel quantity and the target fuel quantity The difference between them is large. However, the multi-injection fuel volume compensating device according to the embodiment of the present invention not only considers the oil volume fluctuation between two adjacent injections, but also considers the influence of the oil volume fluctuation between two separate injections. Therefore, compared with the prior art method of compensating the subsequent injection only based on the fuel quantity fluctuation compensation model established based on the data of two adjacent injections, the multi-injection fuel quantity compensating device described in the embodiment of the present invention can The oil quantity injected for each engine working cycle is compensated more accurately, so that the actual injected oil quantity is close to the target value given by the ECU, so as to ensure the stability of the engine torque output and the emission characteristics of the engine.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (8)

1. A method for compensating the amount of fuel injected multiple times, characterized in that the method comprises: determining the first hydraulic delay time for the i-th injection, the second hydraulic delay time for the i+1-th injection, and, According to the engine water temperature and the temperature value before the fuel oil passes through the fuel filter, the oil temperature influence coefficient is determined, and the oil temperature influence coefficient indicates the degree of influence of the fuel temperature on the fuel density and fuel pressure; Determining the first corrected oil quantity of the i-th injection to the i+2-th injection and the second corrected oil quantity of the i+1-th injection to the i+2-th injection, wherein i is 1 All integers between N-2, N is the number of injections of the injector in one working cycle of the engine, specifically including: According to the first hydraulic delay time, the oil temperature influence coefficient, the first target oil quantity of the i-th injection, and the first time interval between the i-th injection and the i+1-th injection, determining the first reference corrected oil quantity of the i-th injection to the i+2-th injection; and, according to the second hydraulic delay time, the oil temperature influence coefficient, the i+1-th injection The second target oil quantity, the second time interval between the i+1th injection and the i+2th injection, determine the i+1th injection versus the i+2th injection Two benchmarks to correct the oil quantity; According to the first target oil quantity, determine a first correction coefficient, the first correction coefficient represents the influence coefficient of the oil quantity of the i-th injection on the i+2-th injection; and, according to the first correction coefficient The third target fuel quantity of i+2 injections and the common rail pressure of the i+1th injection determine a second correction coefficient, and the second correction coefficient represents the relationship between the third target fuel quantity and the ith +2 Influence coefficient of injection; multiplying the first reference correction oil quantity by the first correction coefficient to obtain the first correction oil quantity; and multiplying the second reference correction oil quantity by the second correction coefficient to obtain The second corrected oil quantity; According to the first corrected oil quantity and the second corrected oil quantity, the target oil quantity of the i+2th injection is compensated. 2. The method according to claim 1, wherein the determining the first hydraulic delay time of the i-th injection and the second hydraulic delay time of the i+1-th injection comprises: receiving a control instruction, and determining the first target oil quantity and the second target oil quantity according to the control instruction, wherein the control instruction includes the first target oil quantity and the second target oil quantity ; Obtain the common rail pressure of the i-th injection, and determine the first hydraulic delay time according to the first target oil quantity, the common-rail pressure of the i-th injection, and the pre-stored first characteristic Map table , wherein, the first feature Map table includes the corresponding relationship between oil quantity, common rail pressure and hydraulic delay time; Obtaining the common rail pressure of the i+1th injection, and determining the Two hydraulic delay time. 3. The method according to claim 1, characterized in that, according to the first hydraulic pressure delay time, the oil temperature influence coefficient, the first target oil quantity of the ith injection, the ith The first time interval between the i-th injection and the i+1-th injection is used to determine the first reference correction oil quantity of the i-th injection to the i+2-th injection, including: The first hydraulic delay time and the first time interval are added together to obtain a first influence time, and the first influence time represents the time period during which the i-th injection has an influence on the i+2-th injection ; multiplying the oil temperature influence coefficient by the first influence time to obtain a first correction time; According to the first target oil quantity, the first correction time, and the pre-stored second characteristic Map table, determine the first reference corrected oil quantity, wherein the second characteristic Map table includes oil quantity, correction time Corresponding relationship with benchmark corrected oil quantity; According to the second hydraulic pressure delay time, the oil temperature influence coefficient, the second target oil quantity of the i+1 injection, the i+1 injection and the i+2 injection The second time interval for determining the i+1th injection to the i+2th injection's second reference corrected oil quantity includes: Adding the second hydraulic delay time and the second time interval to obtain a second influence time, the second influence time indicates that the i+1th injection has an influence on the i+2th injection the duration of multiplying the oil temperature influence coefficient by the second influence time to obtain a second correction time; The second reference corrected oil quantity is determined according to the second target oil quantity, the second correction time, and the second characteristic Map table. 4. The method according to any one of claims 1-3, characterized in that, according to the first corrected oil quantity and the second corrected oil quantity, the i+2th injection target Oil volume compensation, including: adding the first corrected oil quantity and the second corrected oil quantity to obtain the compensated oil quantity; If the compensation oil amount is greater than the first preset correction value and smaller than the second preset correction value, the third target oil amount is compensated according to the compensation oil amount. 5. A multi-injection oil volume compensation device, characterized in that the device includes: a hydraulic delay time determination unit, an oil temperature influence coefficient determination unit, a corrected oil volume determination unit, and a compensation unit; The hydraulic delay time determination unit is used to determine the first hydraulic delay time of the i-th injection and the second hydraulic delay time of the i+1-th injection; The oil temperature influence coefficient determination unit determines the oil temperature influence coefficient according to the engine water temperature and the temperature value before the fuel passes through the fuel filter, and the oil temperature influence coefficient indicates the degree of influence of fuel temperature on fuel density and fuel pressure; The corrected oil quantity determining unit is used to determine the first corrected oil quantity of the i-th injection to the i+2-th injection and the first corrected oil quantity of the i+1-th injection to the i+2-th injection 2. Correction of oil quantity, wherein, i takes all integers between 1 and N-2, and N is the number of injections of the fuel injector in one working cycle of the engine, specifically including: a reference correction oil quantity determination module, a correction coefficient determination module, a correction Oil calculation module; The reference corrected oil quantity determination module is configured to determine the first hydraulic pressure delay time, the oil temperature influence coefficient, the first target oil quantity of the i-th injection, the i-th injection and the In the first time interval of the i+1 injection, determine the first reference corrected oil quantity of the i-th injection to the i+2-th injection; and, according to the second hydraulic delay time, the oil temperature influence coefficient, the second target oil quantity of the i+1 injection, and the second time interval between the i+1 injection and the i+2 injection, determine the i+1 injection The second reference corrected oil quantity for the i+2th injection; The correction coefficient determination module is configured to determine a first correction coefficient according to the first target oil quantity, and the first correction coefficient represents the oil quantity of the i-th injection to the i+2-th injection influence coefficient; and, according to the third target oil quantity of the i+2th injection and the common rail pressure of the i+1th injection, determine a second correction coefficient, the second correction coefficient represents the The influence coefficient of the three-target oil quantity on the i+2 injection; The corrected oil volume calculation module is configured to multiply the first reference corrected oil volume by the first correction coefficient to obtain the first corrected oil volume; The second correction coefficient is multiplied to obtain the second correction oil quantity; The compensation unit is configured to compensate the target oil amount of the i+2th injection according to the first corrected oil amount and the second corrected oil amount. 6. The device according to claim 5, wherein the hydraulic delay time determining unit specifically comprises: a control instruction receiving module, a target oil quantity determining module, a common rail pressure obtaining module, and a hydraulic delay time determining module; The control instruction receiving module is configured to receive a control instruction, wherein the control instruction includes the first target oil quantity and the second target oil quantity; The target oil quantity determination module is configured to determine the first target oil quantity and the second target oil quantity according to the control instruction; The common rail pressure obtaining module is used to obtain the common rail pressure of the i-th injection; The hydraulic delay time determination module is configured to determine the first hydraulic delay time according to the first target oil quantity, the common rail pressure of the i-th injection, and a pre-stored first characteristic Map table, wherein, The first feature Map table includes the corresponding relationship between oil quantity, common rail pressure and hydraulic delay time; The common rail pressure obtaining module is also used to obtain the common rail pressure of the i+1th injection; The hydraulic delay time determining module is further configured to determine the second hydraulic delay time according to the second target oil quantity, the common rail pressure of the (i+1)th injection, and the first characteristic Map table . 7. The device according to claim 5, wherein the reference correction oil quantity determination module is specifically used for: The first hydraulic delay time and the first time interval are added together to obtain a first influence time, and the first influence time represents the time period during which the i-th injection has an influence on the i+2-th injection ; multiplying the oil temperature influence coefficient by the first influence time to obtain a first correction time; According to the first target oil quantity, the first correction time, and the pre-stored second characteristic Map table, determine the first reference corrected oil quantity, wherein the second characteristic Map table includes oil quantity, correction time Corresponding relationship with benchmark corrected oil quantity; The reference correction oil quantity determination module is also specifically used for: Adding the second hydraulic delay time and the second time interval to obtain a second influence time, the second influence time indicates that the i+1th injection has an influence on the i+2th injection the duration of multiplying the oil temperature influence coefficient by the second influence time to obtain a second correction time; The second reference corrected oil quantity is determined according to the second target oil quantity, the second correction time, and the second characteristic Map table. 8. The device according to any one of claims 5-7, characterized in that the compensation unit specifically includes: a compensation oil volume calculation module and a compensation module; The compensation oil amount calculation module is used to add the first corrected oil amount and the second corrected oil amount to obtain the compensated oil amount; The compensation module is configured to compensate a third target oil amount according to the compensation oil amount if the compensation oil amount is greater than a first preset correction value and smaller than a second preset correction value.