A method for calculating fuel injection quantity

Abstract

The present invention discloses a method for calculating the amount of fuel injection, comprising: obtaining an input signal of a current sampling period; estimating an input signal of a future sampling period; determining the density of fresh air entering a cylinder in a future sampling period based on the estimated input signal; obtaining the remaining time for closing the intake valve of each cylinder; estimating the transient value of the intake density at the moment when the intake valve of each cylinder is closed based on the density of fresh air entering the cylinder in the future sampling period and the remaining time for closing the intake valve of each cylinder; estimating the final value of the intake density when the intake valve of each cylinder is closed based on the input signal of the current sampling period and the estimated transient value of the intake density of each cylinder; and obtaining the amount of fuel injection based on the final value of the intake density when the intake valve of each cylinder is closed, the volume of a single cylinder, and a target air-fuel ratio.

Description

Technical Field

[0001] The present invention relates to the field of engine control, and in particular to a method for calculating fuel injection quantity. Background Art

[0002] The engine's air intake system transfers atmospheric gas to the cylinder. The air intake system is complex and tortuous, and the engine's operating conditions change rapidly. The control of the fuel injection amount is determined based on the amount of air entering the cylinder and the air-fuel ratio requirements. The amount of air entering the cylinder refers to the amount of air entering the cylinder when the intake valve is closed. However, if the amount of air entering the cylinder is calculated only when the intake valve is closed, it is too late, because the engine will inject fuel during the intake stroke, and fuel injection takes time, especially multi-injection control, that is, fuel injection is achieved before the intake valve is closed, thereby improving emissions and combustion stability. Based on this, we need to estimate the amount of air entering the cylinder at the moment the intake valve closes before the intake valve closes. Based on this, this patent proposes real-time estimation of the amount of air entering the cylinder at the moment the intake valve closes, so as to achieve the setting of the fuel injection amount, thereby ensuring timely and accurate control of fuel injection.

[0003] Prior art CN202011247317.7, "Method and System for Estimating Fresh Air Flow Entering a Cylinder," discloses a method for estimating fresh air flow entering a cylinder. The method includes the following steps: obtaining the fresh air flow entering the cylinder before fitting; determining whether all fitting parameter estimation accuracy conditions are met, and if so, calculating the fitting parameters; and calculating the estimated fresh air flow entering the cylinder based on the fitting parameters. This solution calculates the current amount of fresh air entering the cylinder, but does not consider estimating the fresh air flow entering the cylinder when the intake valve is closed.

[0004] Existing technology CN202210687977.X "Engine intake correction method and engine system"

[0005] Provided is a method for correcting the intake air volume of an engine and an engine system, wherein the correction method includes the following steps: obtaining a conversion coefficient between the oil volume and the excess air coefficient; and a feedforward correction value M obtained from the last correction calculation; obtaining an excess air coefficient model value Lambda based on the conversion coefficient; and the feedforward correction value M obtained from the last correction calculation; obtaining an excess air coefficient measured value Lambda, and obtaining an oil volume correction value Δm based on the excess air coefficient measured value Lambda, the excess air coefficient model value Lambda and the conversion coefficient; obtaining an injection volume m, and obtaining a feedforward correction value M based on the oil volume correction value Δm and the injection volume m, to complete this correction calculation; and adjusting the intake air volume of the engine based on the feedforward correction value obtained from each correction calculation. This solution calculates the optimized amount of fresh air entering the cylinder, but it does not consider estimating the amount of fresh air entering the cylinder at the moment when the intake valve is closed. Summary of the Invention

[0006] The object of the present invention is to provide a method for calculating the fuel injection amount so as to accurately calculate the fuel injection amount.

[0007] To solve the above technical problems, the present invention provides a technical solution: a method for calculating the fuel injection amount, comprising:

[0008] Get the input signal of the current sampling period;

[0009] Estimate the input signal for future sampling periods;

[0010] Determine the density of fresh air entering the cylinder in future sampling periods based on the estimated input signal;

[0011] Get the remaining closing time of each cylinder intake valve;

[0012] Based on the fresh air density entering the cylinder in the future sampling period and the remaining closing time of the intake valve of each cylinder, the transient value of the intake density at the closing moment of the intake valve of each cylinder is estimated;

[0013] According to the input signal of the current sampling period and the estimated transient value of the intake density of each cylinder, the final value of the intake density when the intake valve of each cylinder is closed is estimated;

[0014] The fuel injection amount is obtained based on the final value of the intake density when the intake valve of each cylinder is closed, the volume of a single cylinder, and the target air-fuel ratio.

[0015] According to the above scheme, the input signal includes:

[0016] 1) All input signals used to calculate the charging efficiency;

[0017] 2) Input signal for calculating intake manifold gas flow correction value;

[0018] 3) Atmospheric pressure detected by the sensor;

[0019] 4) Throttle inlet gas pressure detected by the sensor;

[0020] 5) Throttle inlet gas temperature detected by the sensor;

[0021] 6) Throttle inlet gas pressure change rate obtained based on the throttle inlet gas pressure;

[0022] 7) Actual effective area of ​​throttle valve; the actual effective area of ​​throttle valve is determined by the actual throttle valve opening detected by the sensor;

[0023] 8) The rate of change of the actual effective area of ​​the throttle valve obtained based on the actual effective area of ​​the throttle valve;

[0024] 9) Throttle actual pressure ratio: The throttle actual pressure ratio is the ratio of the actual pressure of the gas at the throttle outlet to the actual pressure of the gas at the throttle inlet;

[0025] 10) A first characteristic parameter; the first characteristic parameter is determined by the throttle inlet gas temperature;

[0026] 11) Actual gas pressure at throttle outlet;

[0027] 12) The actual pressure change rate of the throttle valve outlet gas obtained based on the actual pressure of the throttle valve outlet gas;

[0028] 13) Actual exhaust gas mass flow rate at the EGR valve outlet;

[0029] 14) Actual EGR rate;

[0030] 15) Gas temperature at the cylinder inlet;

[0031] 16) Mass flow of fresh air entering the cylinder;

[0032] 17) Density of the mixture entering the cylinder; The density of the mixture entering the cylinder is determined by the actual pressure of the gas at the throttle outlet, the gas temperature at the inlet of the cylinder intake valve, and the charging efficiency;

[0033] 18) Engine speed;

[0034] 19) Number of engine cylinders;

[0035] 20) Engine single cylinder volume;

[0036] 21) The mass flow rate of the mixture entering the cylinder; the mass flow rate of the mixture entering the cylinder is determined by the density of the mixture entering the cylinder.

[0037] According to the above scheme, the default value is defined as the first value when the vehicle is powered on. The default value of the input signal includes:

[0038] 1) The default value of the intake pressure is the actual pressure of the throttle outlet gas read in real time;

[0039] 2) The default value of the intake manifold gas flow correction value is 0;

[0040] 3) The default value of the crankcase ventilation flow introduced into the cylinder through the intake manifold is 0;

[0041] 4) The default value of the crankcase ventilation PCV pipe pressure is the real-time atmospheric pressure;

[0042] 5) The fresh air mass flow rate entering the cylinder is the real-time reading of the mixed gas mass flow rate entering the cylinder;

[0043] 6) The default value of the fresh air density entering the cylinder is the real-time reading of the mixed gas density entering the cylinder;

[0044] 7) The default value of the mass flow rate of the mixed gas entering the cylinder is the real-time reading of the mass flow rate of the mixed gas entering the cylinder;

[0045] 8) The default value of the density of the mixed gas entering the cylinder is the real-time reading of the density of the mixed gas entering the cylinder;

[0046] 9) The default value of inflation efficiency is 0;

[0047] 10) The default value of the actual effective area of ​​the throttle valve is the actual effective area of ​​the throttle valve read in real time;

[0048] 11) The default value of the gas mass flow rate flowing through the throttle valve is the real-time reading of the mixed gas mass flow rate entering the cylinder;

[0049] 12) The default value of the actual throttle pressure ratio is 1;

[0050] 13) The default value of the throttle valve pressure ratio flow coefficient is 1; the throttle valve pressure ratio flow coefficient is used to calculate the actual effective area of ​​the throttle valve and the actual intake flow;

[0051] 14) The default value of the throttle gas flow characteristic parameter is 1; after the vehicle is powered on, the throttle gas flow characteristic parameter is determined by the throttle pressure ratio flow coefficient, the actual effective area of ​​the throttle, and the throttle inlet gas temperature;

[0052] 15) The default value of the throttle inlet gas pressure is the real-time atmospheric pressure;

[0053] 16) The default value of the weighting coefficient is 1; the weighting coefficient is determined by the actual throttle outlet gas pressure and the throttle inlet gas pressure after the vehicle is powered on.

[0054] According to the above solution, the method for updating the input signal includes:

[0055] 1) Update the actual throttle pressure ratio based on the actual throttle outlet gas pressure and the throttle inlet gas pressure detected by the sensor;

[0056] 2) updating the gas mass flow rate through the throttle valve based on the real-time acquired throttle valve inlet gas pressure, throttle valve actual effective area, throttle valve inlet gas temperature, and throttle valve outlet gas actual pressure;

[0057] 3) updating the inflation efficiency based on the real-time values ​​of all input signals used to calculate the inflation efficiency;

[0058] 4) updating the density of the mixed gas entering the cylinder based on the real-time acquired gas temperature at the cylinder intake valve inlet, the actual gas pressure at the throttle valve outlet, and the updated charging efficiency;

[0059] 5) Update the mixture mass flow rate according to the updated mixture density entering the cylinder;

[0060] 6) updating the weighting coefficient based on the actual pressure of the gas at the throttle outlet and the gas pressure at the throttle inlet obtained in real time; updating the intake manifold gas flow correction value based on the value of the intake manifold gas flow correction value in the previous sampling period;

[0061] 7) Update the intake pressure using the target intake pressure value obtained in real time;

[0062] 8) Update the throttle gas flow characteristic parameters; update the throttle actual pressure ratio; update the throttle pressure ratio flow coefficient according to the throttle actual pressure ratio; update the gas mass flow rate flowing through the throttle;

[0063] 9) updating the inflation efficiency based on the real-time values ​​of all input signals used to calculate the inflation efficiency;

[0064] 10) updating the density of the mixed gas entering the cylinder based on the real-time acquired gas temperature at the cylinder intake valve inlet, the actual gas pressure at the throttle valve outlet, and the updated charging efficiency;

[0065] 11) updating the density of fresh air entering the cylinder based on the actual EGR rate and the updated density of the mixture entering the cylinder obtained in real time;

[0066] 12) Update the mixture mass flow rate according to the updated mixture density entering the cylinder;

[0067] 13) Update the fresh air mass flow entering the cylinder according to the updated mixture mass flow entering the cylinder and the actual EGR rate obtained in real time.

[0068] According to the above solution, the method for estimating the input signal of the future sampling period includes:

[0069] Estimate the input signal of the next sampling period;

[0070] sequentially estimating input signals of subsequent sampling periods of the next sampling period;

[0071] The method for estimating the input signal of the next sampling period includes:

[0072] 1) Based on the updated input signal of the current sampling period and the real-time input signal acquired during the current sampling period, estimate the weighting coefficient and intake pressure change rate of the next sampling period;

[0073] 2) Based on the throttle inlet gas pressure and the throttle inlet gas pressure change rate of the current sampling period, estimate the throttle inlet gas pressure of the next sampling period, and limit the estimated throttle inlet gas pressure to a set range;

[0074] 3) Based on the actual effective throttle area and the rate of change of the actual effective throttle area in the current sampling period, estimate the actual effective throttle area in the next sampling period, and limit the estimated actual effective throttle area to a set range;

[0075] 4) estimating a correction value of the intake manifold gas flow rate for the next sampling period based on the estimated absolute value of the intake manifold intake pressure change rate;

[0076] 5) Based on the estimated intake pressure change rate and the intake pressure obtained in the current sampling period, estimate the intake pressure in the next sampling period and limit the estimated intake pressure to a set range;

[0077] 6) Estimate the throttle gas flow characteristic parameters, actual throttle pressure ratio, throttle pressure ratio flow coefficient, and gas mass flow through the throttle in the next sampling period;

[0078] 7) Estimate the charging efficiency of the next sampling period based on the updated intake pressure;

[0079] 8) Based on the estimated intake pressure, charging efficiency, and the gas temperature at the cylinder intake valve inlet, estimate the mixture density entering the cylinder in the next sampling period;

[0080] 9) Based on the estimated density of the mixed gas entering the cylinder, estimate the mass flow rate of the mixed gas entering the cylinder in the next sampling period;

[0081] 10) Based on the estimated density of the mixture entering the cylinder and the actual EGR rate obtained in real time during the current sampling period, estimate the density of the fresh air entering the cylinder during the next sampling period;

[0082] 11) Based on the estimated mass flow of the mixed gas entering the cylinder and the actual EGR rate obtained in real time during the current sampling period, estimate the mass flow of fresh air entering the cylinder during the next sampling period;

[0083] 12) Estimate the actual EGR rate for the next sampling period based on the actual EGR rate obtained in real time during this sampling period, the actual exhaust gas mass flow rate at the EGR valve outlet, the gas temperature at the cylinder intake valve inlet, and the estimated mass flow rate of the mixed gas entering the cylinder.

[0084] According to the above solution, the method for sequentially estimating the input signals of subsequent sampling periods of the next sampling period includes:

[0085] estimating the input signal in the subsequent sampling period based on the input signal acquired in real time in the previous sampling period and the updated input signal;

[0086] The estimated input signals of all sampling periods after the Nth sampling period are set as the estimated input signals of the Nth sampling period.

[0087] According to the above scheme, the method for estimating the transient value of the intake density at the closing moment of the intake valve of each cylinder based on the fresh air density entering the cylinder in the future sampling period and the remaining closing time of the intake valve of each cylinder includes:

[0088] Determining the closing time of the intake valve of each cylinder according to the remaining closing time of the intake valve of each cylinder;

[0089] If the closing moment of the intake valve of a certain cylinder is between two adjacent sampling periods, the fresh air density entering the cylinder corresponding to the two sampling periods is linearly interpolated to obtain the transient value of the intake density at the closing moment of the intake valve of the cylinder.

[0090] According to the above solution, the method for estimating the final value of the intake density of each cylinder when the intake valve is closed based on the input signal of the current sampling period and the estimated transient value of the intake density of each cylinder includes:

[0091] The final value of the intake density when the intake valve of each cylinder is closed is estimated based on the obtained transient operating condition coefficient, the density of the fresh air entering the cylinder during the current sampling period, and the transient value of the intake density when the intake valve of each cylinder is closed.

[0092] The present invention also provides a fuel injection amount calculation device, comprising:

[0093] An input signal acquisition module is used to obtain the input signal of the current sampling period;

[0094] Input signal estimation module, used to estimate the input signal of future sampling periods;

[0095] A module for determining the density of fresh air entering the cylinder in the future, for determining the density of fresh air entering the cylinder in the future sampling period according to the estimated input signal;

[0096] A cylinder intake valve closing remaining time determination module is used to obtain the remaining closing time of each cylinder intake valve;

[0097] The intake density transient value estimation module is used to estimate the intake density transient value of each cylinder at the moment of intake valve closing based on the fresh air density entering the cylinder in the future sampling period and the remaining time for the intake valve of each cylinder to close;

[0098] An intake density final value estimation module is used to estimate the final intake density value of each cylinder when the intake valve is closed based on the input signal of the current sampling period and the estimated transient value of the intake density of each cylinder;

[0099] The fuel injection amount determination module is used to obtain the fuel injection amount based on the final value of the intake density when the intake valve of each cylinder is closed, the volume of a single cylinder, and the target air-fuel ratio.

[0100] According to the above scheme, the input signal includes:

[0101] 1) All input signals used to calculate the charging efficiency;

[0102] 2) Input signal for calculating intake manifold gas flow correction value;

[0103] 3) Atmospheric pressure detected by the sensor;

[0104] 4) Throttle inlet gas pressure detected by the sensor;

[0105] 5) Throttle inlet gas temperature detected by the sensor;

[0106] 6) Throttle inlet gas pressure change rate obtained based on the throttle inlet gas pressure;

[0107] 7) Actual effective area of ​​throttle valve; the actual effective area of ​​throttle valve is determined by the actual throttle valve opening detected by the sensor;

[0108] 8) The rate of change of the actual effective area of ​​the throttle valve obtained based on the actual effective area of ​​the throttle valve;

[0109] 9) Throttle actual pressure ratio: The throttle actual pressure ratio is the ratio of the actual pressure of the gas at the throttle outlet to the actual pressure of the gas at the throttle inlet;

[0110] 10) A first characteristic parameter; the first characteristic parameter is determined by the throttle inlet gas temperature;

[0111] 11) Actual gas pressure at throttle outlet;

[0112] 12) The actual pressure change rate of the throttle valve outlet gas obtained based on the actual pressure of the throttle valve outlet gas;

[0113] 13) Actual exhaust gas mass flow rate at the EGR valve outlet;

[0114] 14) Actual EGR rate;

[0115] 15) Gas temperature at the cylinder inlet;

[0116] 16) Mass flow of fresh air entering the cylinder;

[0117] 17) Density of the mixture entering the cylinder; The density of the mixture entering the cylinder is determined by the actual pressure of the gas at the throttle outlet, the gas temperature at the inlet of the cylinder intake valve, and the charging efficiency;

[0118] 18) Engine speed;

[0119] 19) Number of engine cylinders;

[0120] 20) Engine single cylinder volume;

[0121] 21) The mass flow rate of the mixture entering the cylinder; the mass flow rate of the mixture entering the cylinder is determined by the density of the mixture entering the cylinder.

[0122] According to the above scheme, the default value is defined as the first value when the vehicle is powered on. The default value of the input signal includes:

[0123] 1) The default value of the intake pressure is the actual pressure of the throttle outlet gas read in real time;

[0124] 2) The default value of the intake manifold gas flow correction value is 0;

[0125] 3) The default value of the crankcase ventilation flow introduced into the cylinder through the intake manifold is 0;

[0126] 4) The default value of the crankcase ventilation PCV pipe pressure is the real-time atmospheric pressure;

[0127] 5) The fresh air mass flow rate entering the cylinder is the real-time reading of the mixed gas mass flow rate entering the cylinder;

[0128] 6) The default value of the fresh air density entering the cylinder is the real-time reading of the mixed gas density entering the cylinder;

[0129] 7) The default value of the mass flow rate of the mixed gas entering the cylinder is the real-time reading of the mass flow rate of the mixed gas entering the cylinder;

[0130] 8) The default value of the density of the mixed gas entering the cylinder is the real-time reading of the density of the mixed gas entering the cylinder;

[0131] 9) The default value of inflation efficiency is 0;

[0132] 10) The default value of the actual effective area of ​​the throttle valve is the actual effective area of ​​the throttle valve read in real time;

[0133] 11) The default value of the gas mass flow rate flowing through the throttle valve is the real-time reading of the mixed gas mass flow rate entering the cylinder;

[0134] 12) The default value of the actual throttle pressure ratio is 1;

[0135] 13) The default value of the throttle valve pressure ratio flow coefficient is 1; the throttle valve pressure ratio flow coefficient is used to calculate the actual effective area of ​​the throttle valve and the actual intake flow;

[0136] 14) The default value of the throttle gas flow characteristic parameter is 1; after the vehicle is powered on, the throttle gas flow characteristic parameter is determined by the throttle pressure ratio flow coefficient, the actual effective area of ​​the throttle, and the throttle inlet gas temperature;

[0137] 15) The default value of the throttle inlet gas pressure is the real-time atmospheric pressure;

[0138] 16) The default value of the weighting coefficient is 1; the weighting coefficient is determined by the actual throttle outlet gas pressure and the throttle inlet gas pressure after the vehicle is powered on.

[0139] The present invention also provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned method for calculating the fuel injection quantity when executing the computer program.

[0140] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the above-mentioned method for calculating the fuel injection amount.

[0141] The beneficial effects of the present invention are: the intake system is complex and curved and the engine operating conditions change rapidly. By designing a model-based prediction algorithm that is continuously iterated and revised, the intake volume entering the cylinder at the moment the intake valve closes is predicted and estimated before the intake valve closes, so as to realize the setting of the injection volume, thereby ensuring timely and accurate control of the injection. BRIEF DESCRIPTION OF THE DRAWINGS

[0142] Figure 1 is a structural diagram of an intake system according to a first embodiment of the present invention;

[0143] Figure 2 This is a flow chart of fuel injection amount calculation according to the first embodiment of the present invention;

[0144] Figure 3 This is a logic block diagram of fuel injection quantity calculation according to the first embodiment of the present invention. DETAILED DESCRIPTION

[0145] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0146] Example 1:

[0147] See also Figure 3 This embodiment discloses a method for calculating the fuel injection amount, comprising the following steps:

[0148] S1. Get the input signal of the current sampling period;

[0149] S2, estimate the input signal of the future sampling period;

[0150] S3. Determine the density of fresh air entering the cylinder in a future sampling period based on the estimated input signal;

[0151] S4. Obtain the remaining closing time of the intake valve of each cylinder;

[0152] S5. estimating the instantaneous value of the intake air density at the closing moment of the intake valve of each cylinder based on the density of the fresh air entering the cylinder in the future sampling period and the remaining closing time of the intake valve of each cylinder;

[0153] S6. Estimate the final intake density value of each cylinder when the intake valve is closed based on the input signal of the current sampling period and the estimated transient intake density value of each cylinder;

[0154] S7. Obtain a fuel injection amount based on a final value of intake air density when the intake valve of each cylinder is closed, a single cylinder volume, and a target air-fuel ratio.

[0155] The method for calculating the fuel injection amount is specifically shown below.

[0156] See also Figure 2 This embodiment discloses an intake density estimation method for determining the fuel injection amount, which estimates the intake density of the cylinder in the future, and then reads the remaining time of the intake valve closing to determine the intake density of the cylinder at the moment when the intake valve is closed. The acquisition method is also an iterative method. Figure 1 Configure the entire engine intake system.

[0157] The intake density estimation method is mainly divided into several steps. The first step is to determine the input signal required by the entire algorithm; the second step is to execute the observer under the current sampling period (the sampling period in this example is 10ms), and the observer outputs various signals under the current sampling period; the third step is to continuously output the predictor under multiple future sampling periods, and the predictor predicts various signals under multiple future sampling periods.

[0158] The first step is to determine the input signals required by the entire algorithm, that is, the general method of obtaining various signals:

[0159] 1) Used to calculate the inflation efficiency r VEAll input signals. Specific input signals can be found in patent CN201910204711.3, "A Method and System for Correcting Charging Efficiency," and Yi Yulan, "Factors Affecting Engine Charging Efficiency and Measures to Improve It," Industry and Technology Forum, 2011.

[0160] 2) Used to calculate the intake manifold gas flow correction value dm in patent CN202210301971.4 "Gas flow calculation method, device and readable storage medium" ManCorr Input signal.

[0161] 3) Atmospheric pressure p Ambient , which can be detected by sensors.

[0162] 4) Throttle inlet gas pressure p PreThrottle , which can be detected by sensors.

[0163] 5) Throttle inlet gas temperature T Thr , which can be detected by sensors.

[0164] 6) Throttle inlet gas pressure change rate dp PreThrottle , is the throttle inlet gas pressure p PreThrottle In order to avoid the problem of drastic pressure change rate caused by large airflow fluctuations and overly aggressive calculation caused by the hysteresis of the intake system, the calculation method of the optimized change rate is as follows:

[0165]

[0166] Where, dp PreThrottle (z) is dp PreThrottle The value of the previous sampling period, the initial default value is 0, p PreThrottle (z) is the throttle inlet gas pressure of the previous sampling period. Its initial default value is the atmospheric pressure value read at that time. c1 is the throttle inlet gas pressure change rate filter time constant, which is 20ms in this example.

[0167] 7) Actual effective area of ​​throttle valve A ThrottleAct , which can be obtained based on the correspondence between the actual throttle opening and the effective throttle area measured by the sensor in patent CN202010109520.1 "Control system and method for electronic throttle of exhaust gas turbocharged engine".

[0168] 8) Throttle actual effective area change rate dA ThrottleAct , is the actual effective area of ​​the throttle valve A ThrottleActIn order to avoid the problem of drastic pressure change rate caused by large airflow fluctuations and overly aggressive calculation caused by the hysteresis of the intake system, the calculation method of the optimized change rate is as follows:

[0169]

[0170] In the formula, dA ThrottleAct (z) is dA ThrottleAct The value of the previous sampling period, the initial default value is 0, A ThrottleAct (z) is the actual effective area of ​​the throttle valve in the previous sampling period. Its initial default value is the maximum effective area of ​​the throttle valve. In this example, it is 2123.7mm 2 , t c2 is the filtering time constant of the actual effective area change rate of the throttle valve, which is 20ms in this example.

[0171] 9) Actual throttle pressure ratio Actual pressure of gas at throttle valve outlet p MAP The actual pressure of the gas at the throttle inlet p PreThrottle Ratio

[0172] 10) Characteristic parameter 1 Where R is the gas constant, which is 287 J / (kg·K) in this example.

[0173] 11) Actual pressure of gas at throttle valve outlet p MAP

[0174] 12) Actual pressure of gas at throttle valve outlet p MAP The rate of change of dp MAP To avoid the problem of drastic pressure change rate changes caused by large airflow fluctuations and overly aggressive calculations due to the hysteresis of the intake system, the calculation method for optimizing the change rate is as follows:

[0175]

[0176] Where, dp MAP (z) is dp MAP The value of the previous sampling period, the initial default value is 0, p MAP (z) is the actual pressure of the throttle outlet gas in the previous sampling period. Its initial default value is the atmospheric pressure value read at that time. c3 is the filtering time constant of the throttle outlet gas pressure change rate, which is 20ms in this example.

[0177] 13) Actual exhaust gas mass flow rate at EGR valve outlet For details, please refer to the gas flow at the EGR valve in patent CN202210756041.8 "A method for controlling an EGR valve of a low-pressure EGR system"

[0178] 14) Actual EGR rate r EGRAct For details, please refer to the EGR rate calculated in patent CN202310312052.1 "Control method, device, electronic device and storage medium of engine system EGR rate".

[0179] 15) Gas temperature T at the cylinder inlet port For details, please refer to the target air intake temperature T finally calculated in patent CN202010752089.2 "Engine Air Inlet Temperature Control Method and System".

[0180] 16) Fresh air mass flow entering the cylinder See patent for details

[0181] CN202011247317.7 "Fresh air flow into the cylinder prediction method and system" estimates the fresh air flow into the cylinder

[0182] 17) Density of the mixture entering the cylinder rho GasCyl , Where M is the molar mass of the mixed gas, which is 29 g / mol in this example, R is the ideal gas constant, which is 8.314 J / (mol·K) in this example, and r VE For the inflation efficiency.

[0183] 18) Engine speed n.

[0184] 19) Number of engine cylinders CNT.

[0185] 20) Engine single cylinder volume V.

[0186] 21) Mass flow of mixed gas entering the cylinder

[0187] The second step is to execute the observer under the current sampling period (the sampling period in this example is 10ms), and the observer outputs various signals under the current sampling period.

[0188] (2.1) First, determine the input signal required to execute the current sampling cycle. The input signal is the default value when the vehicle is powered on and is only executed once. When calculating the next sampling cycle, the same input signal still directly uses the output signal calculated in the previous sampling cycle. The initial default value is set as follows:

[0189] 1) Inlet pressure p MAPThe default value is the real-time actual intake pressure read, that is, the actual pressure of the throttle outlet gas p MAP .

[0190] 2) Intake manifold gas flow correction value dmManCorr The default value is 0.

[0191] 3) The flow of crankcase ventilation introduced into the cylinder through the intake manifold dmCC The default value is 0.

[0192] 4) Crankcase ventilation PCV pipe pressure p CC The default value is the current actual atmospheric pressure p Ambient .

[0193] 5) Fresh air mass flow entering the cylinder The default value is the actual mass flow of the mixed gas entering the cylinder. When the vehicle is powered on, the mixture consists of only fresh air.

[0194] 6) Density of fresh air entering the cylinder rho AirCyl The default value is the current actual density of the mixed gas entering the cylinder, rho GasCyl When the vehicle is powered on, the mixture consists only of fresh air.

[0195] 7) Mass flow of mixed gas entering the cylinder The default value is the actual mass flow of the mixed gas entering the cylinder.

[0196] 8) Density of the mixture entering the cylinder rho GasCyl The default value is the current actual density of the mixed gas entering the cylinder, rho GasCyl .

[0197] 9) Inflating efficiency r VE The default value is 0.

[0198] 10) Actual effective area of ​​throttle valve A ThrottleAct The default value is the actual effective area A of the throttle valve. ThrottleAct .

[0199] 11) Mass flow of gas flowing through the throttle The default value is the actual mass flow of the mixed gas entering the cylinder.

[0200] 12) Actual throttle pressure ratio The default value is 1.

[0201] 13) Throttle pressure ratio flow coefficient The default value is 1. Patent

[0202] The parameters corresponding to the throttle target effective area and the throttle target intake flow can be seen in CN202010109520.1 "Control system and method for exhaust gas turbocharged engine electronic throttle" Similarly, the actual effective area of ​​the throttle and the actual intake flow are calculated using

[0203] 14) Throttle gas flow characteristic parameter K ThrManDyn The default value is 1. Under normal circumstances, the throttle gas flow characteristic parameter K ThrManDyn Pick

[0204] 15) Throttle inlet gas pressure p PreThrottle The default value is the current actual atmospheric pressure p Ambient .

[0205] 16) Coefficient rUseMAP The default value is 1. rUseMAP The definition and the acquisition method under normal circumstances can be found in patent CN202210301971.4 "Gas flow calculation method, device and readable storage medium".

[0206] (2.2) After determining all the above input signals, complete the following tasks:

[0207] 1) Update the actual throttle pressure ratio where p MAP According to the acquisition method (2.1), p PreThrottle The sensor value read in real time

[0208] 2) Update the gas mass flow rate flowing through the throttle where p MAP According to the acquisition method (2.1), p PreThrottle 、A ThrottleAct 、T Thr Information is read in real time. is p obtained according to the method of (2.1) MAP And the real-time read p PreThrottle Obtained, the acquisition method can be found in patent CN202210755703.X "A method for controlling an electronic throttle valve of a supercharged direct injection gasoline engine".

[0209] 3) Update the inflation efficiency r VE , calculate the inflation efficiency r based on real-time data signals VE .

[0210] 4) Update the density of the mixture entering the cylinder rho GasCyl , where p MAP According to the acquisition method of (2.1), the inflation efficiency r VE The other signals in this formula are obtained in real time.

[0211] 5) Update the mass flow of the mixed gas entering the cylinder where rho GasCyl According to step 4), n is the engine speed obtained in real time.

[0212] 6) Based on the updated information above, update the coefficient rUseMAP , update the intake manifold gas flow correction value dmManCorr For the specific update method, please refer to patent CN202210301971.4 "Gas flow calculation method, device and readable storage medium".

[0213] 7) Update intake pressure p MAP , take the target intake pressure value p obtained in real time from patent CN202210344294.4 "Model optimization method, device, equipment and readable storage medium for intake pressure" s .

[0214] 8) Update the throttle gas flow characteristic parameter K ThrManDyn , update the actual throttle pressure ratio Update throttle valve pressure ratio flow coefficient Update the gas mass flow rate flowing through the throttle

[0215] 9) Update the inflation efficiency r VE , calculate the inflation efficiency r based on real-time data signals VE .

[0216] 10) Update the density of the mixture entering the cylinder rho GasCyl , where p MAP According to the acquisition method of (2.1), the inflation efficiency r VE It is obtained in step 9), and the other signals in this formula are signals obtained in real time.

[0217] 11) Update the fresh air density rho entering the cylinder AirCyl , rho AirCyl =rho GasCyl ×(1-r EGRAct ), where r EGRAct is the actual EGR rate during the current sampling period.

[0218] 12) Update the mass flow of the mixed gas entering the cylinder where rho GasCyl Obtained according to step 10), n is the engine speed obtained in real time.

[0219] 13) Update the fresh air mass flow entering the cylinder

[0220] The third step is to estimate the observer under the next sampling period, and the observer outputs various signals under the next sampling period.

[0221] 1) Estimate the coefficient r for the next sampling period UseMAP-1 For specific update methods, see patent CN202210301971.4, "Gas Flow Calculation Method, Apparatus, and Readable Storage Medium." The input signals required for this estimation method come from the updated data during the current sampling period and the real-time data read (real-time data includes data not updated during the current sampling period). The same applies to the following.

[0222] 2) Estimate the intake manifold intake pressure change rate dp in the next sampling period Man-1 The specific update method can also be found in patent CN202210301971.4 "Gas flow calculation method, device and readable storage medium". The input signal required for its estimation method comes from the data updated in this sampling period and the data read in real time (the data read in real time includes the data not updated in this sampling period). In this patent, the intake pressure change rate dp Man-1 The acquisition of the intake manifold gas flow correction value dm calculated in real time will be used ManCorr .

[0223] 3) Estimate the throttle inlet gas pressure p in the next sampling period PreThrottle-1 , p PreThrottle-1 The initial value is p PreThrottle +Δt×dp PreThrottle , and restrict it to p PreThrottle +Δp Max and p PreThrottle +Δp Min Internal (based on the range of the engine's own throttle inlet gas pressure change characteristics, while avoiding the phenomenon of the prediction observer not being able to converge to improve the prediction control accuracy, this example Δp Max and Δp Min Take 200kPa and -200kPa respectively), where p PreThrottle is the throttle inlet gas pressure during this sampling period (not the next estimated sampling period), Δt is the sampling period, which is 10ms in this example, and dp PreThrottleis the rate of change of gas pressure at the throttle inlet during this sampling period.

[0224] 4) Estimate the actual effective area A of the throttle valve in the next sampling period ThrottleAct-1

[0225] Actual effective area A ThrottleAct-1 The initial value is A ThrottleAct +Δt×dA ThrottleAct , and restrict it to A ThrottleAct +ΔA Max and A ThrottleAct +ΔA Min Internal (based on the range of the engine's own throttle effective area variation characteristics, while avoiding the phenomenon of the prediction observer not being able to converge to improve the prediction control accuracy, this example ΔA Max and ΔA Min Take 2000mm respectively 2 and -2000mm 2 ), where A ThrottleAct is the actual effective area of ​​the throttle valve in this sampling period (not the estimated next sampling period), Δt is the sampling period, which is 10ms in this example, and dA ThrottleAct is the actual effective area change rate of the throttle during this sampling period

[0226] 5) Estimate the intake manifold gas flow correction value dm in the next sampling period ManCorr-1 :

[0227] dm ManCorr-1 =dm ManCorr +f(|dp Man-1 |), where f(|dp Man-1 |) is the intake manifold intake pressure change rate dp estimated for the next sampling period Man-1 The absolute value function of .

[0228]

[0229] This determination method, on the one hand, avoids the situation where a large update to the intake manifold gas flow correction value during large intake pressure changes would further increase the intake manifold pressure change rate, thereby preventing control convergence. On the other hand, iterative dynamic adjustment of the intake manifold gas flow correction value is performed only when the intake pressure changes are small, improving intake air volume control accuracy. This calibration method ultimately ensures that the intake air volume, compared to the installed intake air volume sensor, is within ±2%.

[0230] 6) Estimate the intake pressure p in the next sampling period MAP-1

[0231] Inlet pressure pMAP-1 The initial value is p MAP +dp Man-1 ×Δt, and limit it to p MAP +Δp MAPMax and p MAP +Δp MAPMin Internal (based on the range of the engine's own throttle effective area variation characteristics, while avoiding the phenomenon of the prediction observer not being able to converge to improve the prediction control accuracy, this example Δp MAPMax and Δp MAPMin Take 200kPa and -200kPa respectively).

[0232] Among them, p MAP The intake pressure obtained during this sampling period (not the estimated next sampling period).

[0233] 7) Estimate the throttle gas flow characteristic parameter K in the next sampling period ThrManDyn-1 , estimate the actual throttle pressure ratio in the next sampling period Estimate the throttle pressure-to-flow coefficient for the next sampling period Estimate the gas mass flow rate through the throttle valve in the next sampling period

[0234] 8) Estimate the inflation efficiency r in the next sampling period VE-1 , the estimation method only uses the updated intake pressure p MAP-1 , other inputs are not updated.

[0235] 9) Estimate the density of the mixed gas entering the cylinder in the next sampling period rho GasCyl-1 ,

[0236]

[0237] 10) Estimate the mass flow rate of the mixed gas entering the cylinder in the next sampling period where rho GasCyl According to step 4), n is the engine speed obtained in real time.

[0238] 11) Estimate the fresh air density rho entering the cylinder in the next sampling period AirCyl-1 , rho AirCyl-1 =rho GasCyl-1 ×(1-r EGRAct ), where r EGRAct The actual EGR rate during this sampling period (not the estimated next sampling period).

[0239] 12) Estimate the fresh air mass flow rate entering the cylinder in the next sampling period

[0240] 13) Estimate the actual EGR rate r in the next sampling period EGRAct-1

[0241] in

[0242] V IntakeManifold is the intake manifold volume, r EGRAct and They are the actual EGR rate in this sampling period (not the estimated next sampling period) and the actual exhaust gas mass flow rate at the EGR valve outlet.

[0243] In the fourth step, the same method is used to estimate the observer in the subsequent sampling period, and the observer outputs various signals in the subsequent sampling period. The input determination method used when estimating various signals in the next sampling period is to determine the updated various input signals based on the previous sampling period and the real-time acquired signals (wherein the real-time acquired signals refer to various signals that have not been updated in the previous sampling period). This example estimates various signals up to the seventh subsequent sampling period (wherein the previously mentioned estimation of the signal in the next sampling period refers to the estimation of the signal in the first subsequent sampling period). The more subsequent sampling periods are estimated, the greater the computing power, and at the same time, the accuracy of subsequent estimates becomes increasingly poor. This example means that the signals beyond the seventh subsequent sampling period are the same as the signals in the seventh sampling period.

[0244] Based on the above method, the fresh air density [rho AirCyl ,rho AirCyl-1 ...,rho AirCyl-N ]. A sampling period of 0 (in ms) refers to the current sampling period, a sampling period of 10 (in ms) refers to the next sampling period, and so on.

[0245] rho AirCyl is the fresh air density entering the cylinder in the current sampling period, rho AirCyl-1 is the density of fresh air entering the cylinder in the next sampling period, and so on.

[0246] The next step is to determine the remaining time for each cylinder's intake valve to close (i.e., the remaining time for the intake valve of cylinder number 1 to close is t1, and so on). The engine design will provide the relationship between the engine crankshaft phase and the cam phase when the VVT ​​is not in effect. Then, when the VVT ​​is in effect, based on the actual intake VVT ​​phase, the relationship between the engine crankshaft phase and the cam phase at the actual VVT phase can be obtained. The intake valve closing position and the cam phase are uniquely determined, so the relationship between the engine crankshaft phase and the intake valve closing position can be known. By reading the crankshaft phase, it is possible to determine how many crankshaft angles are required for the intake valve to close. Based on the current engine speed, the remaining time for each cylinder's intake valve to close can be determined.

[0247] Based on the determined remaining time [t1, t2, ..., t CNT ], and the fresh air density [rho AirCyl ,rho AirCyl-1 ...,rho AirCyl-N ], linear interpolation is used to obtain the estimated transient value of intake density rho of each cylinder AirCylTrans (The linear interpolation method is that if the remaining time is between a certain sampling period and the adjacent sampling period, the estimated intake density corresponding to the two sampling periods is used to interpolate to obtain the transient value of the intake density at the moment when the intake valve is closed. In particular, if the remaining time is greater than 10×N ms, then rho AirCyl-N as the transient value of intake air density at the moment of intake closing).

[0248] The density of fresh air entering the cylinder during the current sampling period is rho AirCyl and the estimated transient intake density rho of each cylinder AirCylTrans , and transient operating coefficient r Trans , we can determine the estimated final intake density rho when the intake valve of each cylinder is closed AirCylFinal ;

[0249] rho AirCylFinal =r Trans ×rho AirCylTrans +(1-r Trans )×rho AirCyl

[0250] Transient operating coefficient r Trans The method for determining is:

[0251] The throttle mentioned in patent CN202210345939.6 "Throttle effective area calculation method, device, equipment and readable storage medium" is in a steady-state working condition, which includes the throttle target intake density is stable, the ratio of throttle flow and effective area is stable, the actual intake pressure at the throttle outlet is stable, the actual intake pressure at the throttle inlet is stable and the throttle is not fully open. If the throttle is in a stable working condition, the transient working condition coefficient r Trans is 0, otherwise the transient operating coefficient r Trans Once the throttle is in a stable working condition, the transient working condition coefficient r Trans Set to 1; however, the transient operating coefficient r Trans The rate of change of the reduction is not less than -0.2 / 10ms.

[0252] Based on this, the estimated final intake density rho of each cylinder when the intake valve is closed is determined AirCylFinal , multiply it by the volume V of a single cylinder to get the intake volume of each cylinder, and divide the intake volume by the target air-fuel ratio to get the target fuel injection volume of the intake cylinder.

[0253] Based on the target injection amount, the injector is controlled to achieve the desired injection amount.

[0254] Example 2:

[0255] This embodiment provides a computer device, such as a smartphone, tablet computer, laptop computer, desktop computer, rack-mounted server, blade server, tower server, or cabinet-mounted server (including a standalone server or a server cluster consisting of multiple servers), capable of executing programs. The computer device of this embodiment includes at least, but is not limited to, a memory and a processor that are communicatively connected via a system bus.

[0256] In this embodiment, the memory (i.e., readable storage medium) includes flash memory, hard disks, multimedia cards, card-type memories (e.g., SD or DX memories), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and programmable read-only memory (PROM). The memory may also be an external storage device of the computer device, such as a plug-in hard disk, a SmartMedia Card (SMC), a Secure Digital (SD) card, a flash memory card, etc. Of course, the memory may also include both the internal storage unit of the computer device and its external storage devices. In this embodiment, the memory is typically used to store the operating system and various application software installed on the computer device, such as the program code of the fuel injection amount calculation method in Example 1. Furthermore, the memory may also be used to temporarily store various data that has been output or is about to be output.

[0257] In some embodiments, the processor may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chip. The processor is generally used to control the overall operation of the computer device. In this embodiment, the processor is used to run the program code stored in the memory or process data, such as running the program code of the fuel injection amount calculation method to implement the fuel injection amount calculation method in Example 1.

[0258] Example 3:

[0259] The present application also provides a computer-readable storage medium, such as a flash memory, a hard disk, a multimedia card, a card-type memory (e.g., an SD or DX memory), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic storage device, a disk, an optical disk, a server, an app store, etc., storing a computer program that, when executed by a processor, implements a corresponding function. The computer-readable storage medium of this embodiment is used to store program code for a method for calculating the amount of fuel injection, and, when executed by a processor, implements the method for calculating the amount of fuel injection in Example 1.

[0260] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, or two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0261] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for calculating fuel injection quantity, characterized in that: include: Get the input signal of the current sampling period; Estimate the input signal for future sampling periods; Determine the density of fresh air entering the cylinder in future sampling periods based on the estimated input signal; Get the remaining closing time of each cylinder intake valve; Based on the fresh air density entering the cylinder in the future sampling period and the remaining closing time of the intake valve of each cylinder, the transient value of the intake density at the closing moment of the intake valve of each cylinder is estimated; According to the input signal of the current sampling period and the estimated transient value of the intake density of each cylinder, the final value of the intake density when the intake valve of each cylinder is closed is estimated; The fuel injection amount is obtained based on the final value of the intake density when the intake valve of each cylinder is closed, the volume of a single cylinder, and the target air-fuel ratio.

2. The method for calculating the fuel injection amount according to claim 1, characterized in that: The input signal includes: 1) All input signals used to calculate the charging efficiency; 2) Input signal for calculating intake manifold gas flow correction value; 3) Atmospheric pressure detected by the sensor; 4) Throttle inlet gas pressure detected by the sensor; 5) Throttle inlet gas temperature detected by the sensor; 6) Throttle inlet gas pressure change rate obtained based on the throttle inlet gas pressure; 7) Actual effective area of ​​throttle valve; the actual effective area of ​​throttle valve is determined by the actual throttle valve opening detected by the sensor; 8) The rate of change of the actual effective area of ​​the throttle valve obtained based on the actual effective area of ​​the throttle valve; 9) Throttle actual pressure ratio: The throttle actual pressure ratio is the ratio of the actual pressure of the gas at the throttle outlet to the actual pressure of the gas at the throttle inlet; 10) A first characteristic parameter; the first characteristic parameter is determined by the throttle inlet gas temperature; 11) Actual gas pressure at throttle outlet; 12) The actual pressure change rate of the throttle valve outlet gas obtained based on the actual pressure of the throttle valve outlet gas; 13) Actual exhaust gas mass flow rate at the EGR valve outlet; 14) Actual EGR rate; 15) Gas temperature at the cylinder inlet; 16) Mass flow of fresh air entering the cylinder; 17) Density of the mixture entering the cylinder; The density of the mixture entering the cylinder is determined by the actual pressure of the gas at the throttle outlet, the gas temperature at the inlet of the cylinder intake valve, and the charging efficiency; 18) Engine speed; 19) Number of engine cylinders; 20) Engine single cylinder volume; 21) The mass flow rate of the mixture entering the cylinder; the mass flow rate of the mixture entering the cylinder is determined by the density of the mixture entering the cylinder.

3. The method for calculating the fuel injection amount according to claim 2, characterized in that: The default values ​​are defined as the initial values ​​when the vehicle is powered on. The default values ​​of the input signals include: 1) The default value of the intake pressure is the actual pressure of the throttle outlet gas read in real time; 2) The default value of the intake manifold gas flow correction value is 0; 3) The default value of the crankcase ventilation flow introduced into the cylinder through the intake manifold is 0; 4) The default value of the crankcase ventilation PCV pipe pressure is the real-time atmospheric pressure; 5) The fresh air mass flow rate entering the cylinder is the real-time reading of the mixed gas mass flow rate entering the cylinder; 6) The default value of the fresh air density entering the cylinder is the real-time reading of the mixed gas density entering the cylinder; 7) The default value of the mass flow rate of the mixed gas entering the cylinder is the real-time reading of the mass flow rate of the mixed gas entering the cylinder; 8) The default value of the density of the mixed gas entering the cylinder is the real-time reading of the density of the mixed gas entering the cylinder; 9) The default value of inflation efficiency is 0; 10) The default value of the actual effective area of ​​the throttle valve is the actual effective area of ​​the throttle valve read in real time; 11) The default value of the gas mass flow rate flowing through the throttle valve is the real-time reading of the mixed gas mass flow rate entering the cylinder; 12) The default value of the actual throttle pressure ratio is 1; 13) The default value of the throttle valve pressure ratio flow coefficient is 1; the throttle valve pressure ratio flow coefficient is used to calculate the actual effective area of ​​the throttle valve and the actual intake flow; 14) The default value of the throttle gas flow characteristic parameter is 1; after the vehicle is powered on, the throttle gas flow characteristic parameter is determined by the throttle pressure ratio flow coefficient, the actual effective area of ​​the throttle, and the throttle inlet gas temperature; 15) The default value of the throttle inlet gas pressure is the real-time atmospheric pressure; 16) The default value of the weighting coefficient is 1; the weighting coefficient is determined by the actual throttle outlet gas pressure and the throttle inlet gas pressure after the vehicle is powered on.

4. The method for calculating the fuel injection amount according to claim 3, characterized in that: The updating method of the input signal includes: 1) Update the actual throttle pressure ratio based on the actual throttle outlet gas pressure and the throttle inlet gas pressure detected by the sensor; 2) updating the gas mass flow rate through the throttle valve based on the real-time acquired throttle valve inlet gas pressure, throttle valve actual effective area, throttle valve inlet gas temperature, and throttle valve outlet gas actual pressure; 3) updating the inflation efficiency based on the real-time values ​​of all input signals used to calculate the inflation efficiency; 4) updating the density of the mixed gas entering the cylinder based on the real-time acquired gas temperature at the cylinder intake valve inlet, the actual gas pressure at the throttle valve outlet, and the updated charging efficiency; 5) Update the mixture mass flow rate according to the updated mixture density entering the cylinder; 6) updating the weighting coefficient based on the actual pressure of the gas at the throttle outlet and the gas pressure at the throttle inlet obtained in real time; updating the intake manifold gas flow correction value based on the value of the intake manifold gas flow correction value in the previous sampling period; 7) Update the intake pressure using the target intake pressure value obtained in real time; 8) Update the throttle gas flow characteristic parameters; update the throttle actual pressure ratio; update the throttle pressure ratio flow coefficient according to the throttle actual pressure ratio; update the gas mass flow rate flowing through the throttle; 9) updating the inflation efficiency based on the real-time values ​​of all input signals used to calculate the inflation efficiency; 10) updating the density of the mixed gas entering the cylinder based on the real-time acquired gas temperature at the cylinder intake valve inlet, the actual gas pressure at the throttle valve outlet, and the updated charging efficiency; 11) updating the density of fresh air entering the cylinder based on the actual EGR rate and the updated density of the mixture entering the cylinder obtained in real time; 12) Update the mixture mass flow rate according to the updated mixture density entering the cylinder; 13) Update the fresh air mass flow entering the cylinder according to the updated mixture mass flow entering the cylinder and the actual EGR rate obtained in real time.

5. The method for calculating the fuel injection amount according to claim 4, characterized in that: The method for estimating an input signal of a future sampling period includes: Estimate the input signal of the next sampling period; sequentially estimating input signals of subsequent sampling periods of the next sampling period; The method for estimating the input signal of the next sampling period includes: 1) Based on the updated input signal of the current sampling period and the real-time input signal acquired during the current sampling period, estimate the weighting coefficient and intake pressure change rate of the next sampling period; 2) Based on the throttle inlet gas pressure and the throttle inlet gas pressure change rate of the current sampling period, estimate the throttle inlet gas pressure of the next sampling period, and limit the estimated throttle inlet gas pressure to a set range; 3) Based on the actual effective throttle area and the rate of change of the actual effective throttle area in the current sampling period, estimate the actual effective throttle area in the next sampling period, and limit the estimated actual effective throttle area to a set range; 4) estimating a correction value of the intake manifold gas flow rate for the next sampling period based on the estimated absolute value of the intake manifold intake pressure change rate; 5) Based on the estimated intake pressure change rate and the intake pressure obtained in the current sampling period, estimate the intake pressure in the next sampling period and limit the estimated intake pressure to a set range; 6) Estimate the throttle gas flow characteristic parameters, actual throttle pressure ratio, throttle pressure ratio flow coefficient, and gas mass flow through the throttle in the next sampling period; 7) Estimate the charging efficiency of the next sampling period based on the updated intake pressure; 8) Based on the estimated intake pressure, charging efficiency, and the gas temperature at the cylinder intake valve inlet, estimate the mixture density entering the cylinder in the next sampling period; 9) Based on the estimated density of the mixed gas entering the cylinder, estimate the mass flow rate of the mixed gas entering the cylinder in the next sampling period; 10) Based on the estimated density of the mixture entering the cylinder and the actual EGR rate obtained in real time during the current sampling period, estimate the density of the fresh air entering the cylinder during the next sampling period; 11) Based on the estimated mass flow of the mixed gas entering the cylinder and the actual EGR rate obtained in real time during the current sampling period, estimate the mass flow of fresh air entering the cylinder during the next sampling period; 12) Estimate the actual EGR rate for the next sampling period based on the actual EGR rate obtained in real time during this sampling period, the actual exhaust gas mass flow rate at the EGR valve outlet, the gas temperature at the cylinder intake valve inlet, and the estimated mass flow rate of the mixed gas entering the cylinder.

6. The method for calculating the fuel injection amount according to claim 5, characterized in that: The method of sequentially estimating input signals of subsequent sampling periods of the next sampling period includes: estimating the input signal in the subsequent sampling period based on the input signal acquired in real time in the previous sampling period and the updated input signal; The estimated input signals of all sampling periods after the Nth sampling period are set as the estimated input signals of the Nth sampling period.

7. The method for calculating the fuel injection amount according to claim 1 or 6, characterized in that: The method for estimating the transient value of the intake density at the closing moment of the intake valve of each cylinder based on the fresh air density entering the cylinder in a future sampling period and the remaining closing time of the intake valve of each cylinder includes: Determining the closing time of the intake valve of each cylinder according to the remaining closing time of the intake valve of each cylinder; If the closing moment of the intake valve of a certain cylinder is between two adjacent sampling periods, the fresh air density entering the cylinder corresponding to the two sampling periods is linearly interpolated to obtain the transient value of the intake density at the closing moment of the intake valve of the cylinder.

8. The method for calculating the fuel injection amount according to claim 6, characterized in that: The method for estimating the final value of the intake density of each cylinder when the intake valve is closed based on the input signal of the current sampling period and the estimated transient value of the intake density of each cylinder includes: The final value of the intake density when the intake valve of each cylinder is closed is estimated based on the obtained transient operating condition coefficient, the density of the fresh air entering the cylinder during the current sampling period, and the transient value of the intake density when the intake valve of each cylinder is closed.

9. A fuel injection amount calculation device, characterized in that: include: An input signal acquisition module is used to obtain the input signal of the current sampling period; Input signal estimation module, used to estimate the input signal of future sampling periods; A module for determining the density of fresh air entering the cylinder in the future, for determining the density of fresh air entering the cylinder in the future sampling period according to the estimated input signal; A cylinder intake valve closing remaining time determination module is used to obtain the remaining closing time of each cylinder intake valve; The intake density transient value estimation module is used to estimate the intake density transient value of each cylinder at the moment of intake valve closing based on the fresh air density entering the cylinder in the future sampling period and the remaining time for the intake valve of each cylinder to close; An intake density final value estimation module is used to estimate the final intake density value of each cylinder when the intake valve is closed based on the input signal of the current sampling period and the estimated transient value of the intake density of each cylinder; The fuel injection amount determination module is used to obtain the fuel injection amount based on the final value of the intake density when the intake valve of each cylinder is closed, the volume of a single cylinder, and the target air-fuel ratio.

10. The fuel injection amount calculation device according to claim 9, characterized in that: The input signal includes: 1) All input signals used to calculate the charging efficiency; 2) Input signal for calculating intake manifold gas flow correction value; 3) Atmospheric pressure detected by the sensor; 4) Throttle inlet gas pressure detected by the sensor; 5) Throttle inlet gas temperature detected by the sensor; 6) Throttle inlet gas pressure change rate obtained based on the throttle inlet gas pressure; 7) Actual effective area of ​​throttle valve; the actual effective area of ​​throttle valve is determined by the actual throttle valve opening detected by the sensor; 8) The rate of change of the actual effective area of ​​the throttle valve obtained based on the actual effective area of ​​the throttle valve; 9) Throttle actual pressure ratio: The throttle actual pressure ratio is the ratio of the actual pressure of the gas at the throttle outlet to the actual pressure of the gas at the throttle inlet; 10) A first characteristic parameter; the first characteristic parameter is determined by the throttle inlet gas temperature; 11) Actual gas pressure at throttle outlet; 12) The actual pressure change rate of the throttle valve outlet gas obtained based on the actual pressure of the throttle valve outlet gas; 13) Actual exhaust gas mass flow rate at the EGR valve outlet; 14) Actual EGR rate; 15) Gas temperature at the cylinder inlet; 16) Mass flow of fresh air entering the cylinder; 17) Density of the mixture entering the cylinder; The density of the mixture entering the cylinder is determined by the actual pressure of the gas at the throttle outlet, the gas temperature at the inlet of the cylinder intake valve, and the charging efficiency; 18) Engine speed; 19) Number of engine cylinders; 20) Engine single cylinder volume; 21) The mass flow rate of the mixture entering the cylinder; the mass flow rate of the mixture entering the cylinder is determined by the density of the mixture entering the cylinder.

11. The fuel injection amount calculation module according to claim 10, characterized in that: The default values ​​are defined as the initial values ​​when the vehicle is powered on. The default values ​​of the input signals include: 1) The default value of the intake pressure is the actual pressure of the throttle outlet gas read in real time; 2) The default value of the intake manifold gas flow correction value is 0; 3) The default value of the crankcase ventilation flow introduced into the cylinder through the intake manifold is 0; 4) The default value of the crankcase ventilation PCV pipe pressure is the real-time atmospheric pressure; 5) The fresh air mass flow rate entering the cylinder is the real-time reading of the mixed gas mass flow rate entering the cylinder; 6) The default value of the fresh air density entering the cylinder is the real-time reading of the mixed gas density entering the cylinder; 7) The default value of the mass flow rate of the mixed gas entering the cylinder is the real-time reading of the mass flow rate of the mixed gas entering the cylinder; 8) The default value of the density of the mixed gas entering the cylinder is the real-time reading of the density of the mixed gas entering the cylinder; 9) The default value of inflation efficiency is 0; 10) The default value of the actual effective area of ​​the throttle valve is the actual effective area of ​​the throttle valve read in real time; 11) The default value of the gas mass flow rate flowing through the throttle valve is the real-time reading of the mixed gas mass flow rate entering the cylinder; 12) The default value of the actual throttle pressure ratio is 1; 13) The default value of the throttle valve pressure ratio flow coefficient is 1; the throttle valve pressure ratio flow coefficient is used to calculate the actual effective area of ​​the throttle valve and the actual intake flow; 14) The default value of the throttle gas flow characteristic parameter is 1; after the vehicle is powered on, the throttle gas flow characteristic parameter is determined by the throttle pressure ratio flow coefficient, the actual effective area of ​​the throttle, and the throttle inlet gas temperature; 15) The default value of the throttle inlet gas pressure is the real-time atmospheric pressure; 16) The default value of the weighting coefficient is 1; the weighting coefficient is determined by the actual throttle outlet gas pressure and the throttle inlet gas pressure after the vehicle is powered on.

12. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the fuel injection quantity calculation method according to any one of claims 1 to 8 are implemented.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for calculating the fuel injection amount according to any one of claims 1 to 8 are implemented.

Images