Fuel injection quantity calculation method

Abstract

The invention discloses a fuel injection quantity calculation method. The method comprises the steps that an input signal of a current sampling period is obtained; estimating an input signal of a future sampling period; according to the pre-estimated input signal, the density of fresh air entering the air cylinder in the future sampling period is determined; the remaining time of closing of the air inlet valves of all the air cylinders is obtained; according to the density of fresh air entering the air cylinders in the future sampling period and the remaining time of closing of the air inlet valves of the air cylinders, air inlet density transient values at the closing moments of the air inlet valves of the air cylinders are estimated; according to the input signal of the current sampling period, the estimated intake density transient value of each air cylinder and the final intake density value when the intake valve of each air cylinder is closed; and the fuel injection quantity is obtained according to the air inlet density final value, the single-cylinder volume and the target air-fuel ratio when the air inlet valves of all the air cylinders are closed.

Description

Technical Field

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

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

[0003] Prior art CN202011247317.7 "Fresh air flow rate estimation method and system entering the cylinder" discloses a method for estimating the fresh air flow rate entering the cylinder, including the following steps: obtaining the fresh air flow rate entering the cylinder before fitting; judging whether the accuracy conditions of all fitting parameter estimates are met, and if so, calculating the fitting parameters; and calculating the estimated fresh air flow rate entering the cylinder based on the fitting parameters. This scheme calculates the current amount of fresh air entering the cylinder, but does not consider estimating the amount of fresh air entering the cylinder at the moment when the intake valve is closed.

[0004] Prior art CN202210687977.X "Engine intake correction method and engine system"

[0005] A method for correcting the intake amount of an engine and an engine system are provided, wherein the correction method includes the following steps: obtaining a conversion coefficient between the oil quantity 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 quantity 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 amount m, and obtaining a feedforward correction value M based on the oil quantity correction value Δm and the injection amount m, to complete this correction calculation; adjusting the intake amount of the engine based on the feedforward correction value obtained from each correction calculation. This scheme 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] In order to solve the above technical problems, the present invention provides a technical solution: a method for calculating the 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 a future sampling period according to the estimated input signal;

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

[0012] According to the density of fresh air entering the cylinder in the future sampling period and the remaining time of closing 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) The rate of change of the throttle inlet gas pressure 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 opening of throttle valve detected by 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) Actual throttle pressure ratio: The actual throttle 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 outlet gas obtained based on the actual pressure of the throttle 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) Fresh air mass flow entering the cylinder;

[0032] 17) Density of the mixed gas entering the cylinder; The density of the mixed gas 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 taken when the vehicle is powered on. The default values ​​of the input signal include:

[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 atmospheric pressure read in real time;

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

[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 mixed gas mass flow rate entering the cylinder is the mixed gas mass flow rate entering the cylinder read in real time;

[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 pressure ratio flow coefficient is 1; the throttle pressure ratio flow coefficient is used to calculate the actual effective area of ​​the throttle 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 scheme, the updating method of the input signal includes:

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

[0056] 2) updating the gas mass flow rate flowing through the throttle according to the real-time acquired throttle inlet gas pressure, the actual effective area of ​​the throttle, the throttle inlet gas temperature, and the throttle outlet gas actual pressure;

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

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

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

[0060] 6) updating the weighting coefficient according to 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 according to the value of the intake manifold gas flow correction value in the previous sampling period;

[0061] 7) updating the intake pressure with 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 charging efficiency according to the real-time values ​​of all input signals used to calculate the charging efficiency;

[0064] 10) updating the density of the mixed gas entering the cylinder according to the real-time acquired gas temperature at the inlet port of the cylinder intake valve, 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 according to the actual EGR rate obtained in real time and the updated density of the mixed gas entering the cylinder;

[0066] 12) updating the mass flow rate of the mixed gas according to the updated density of the mixed gas entering the cylinder;

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

[0068] According to the above scheme, 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 comprises:

[0072] 1) According to the updated input signal of the current sampling period and the input signal acquired in real time of the current sampling period, the weighting coefficient and the intake pressure change rate of the next sampling period are estimated;

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

[0074] 3) According to the actual effective area of ​​the throttle valve and the rate of change of the actual effective area of ​​the throttle valve in the current sampling period, the actual effective area of ​​the throttle valve in the next sampling period is estimated, and the estimated actual effective area of ​​the throttle valve is limited to a set range;

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

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

[0077] 6) Estimate the throttle gas flow characteristic parameters, the actual throttle pressure ratio, the throttle pressure ratio flow coefficient, and the gas mass flow rate flowing 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 gas temperature at the intake port of the cylinder intake valve, estimate the density of the mixed gas 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 mixed gas entering the cylinder and the actual EGR rate obtained in real time during the current sampling period, the density of the fresh air entering the cylinder during the next sampling period is estimated;

[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 of 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 scheme, the method for sequentially estimating the input signals of subsequent sampling periods of the next sampling period includes:

[0085] According to the input signal acquired in real time in the previous sampling period and the updated input signal, the input signal in the subsequent sampling period is estimated;

[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 according to the fresh air density entering the cylinder in the future sampling period and the remaining time of closing the intake valve of each cylinder includes:

[0088] Determine 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 cylinder is between two adjacent sampling periods, the density of fresh air 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 scheme, the method for 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 includes:

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

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

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

[0094] An input signal estimation module is used to estimate the input signal of the future sampling period;

[0095] A module for determining the density of fresh air entering the cylinder in the future, used 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] An intake density transient value estimation module is used to estimate the intake density transient value of each cylinder at the closing moment of the intake valve according to the fresh air density entering the cylinder in the future sampling period and the remaining closing time of the intake valve of each cylinder;

[0098] An intake density final value estimation module is used to estimate the intake density final 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 according to 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) The rate of change of the throttle inlet gas pressure 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 opening of throttle valve detected by 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) Actual throttle pressure ratio: The actual throttle 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 outlet gas obtained according to the actual pressure of the throttle 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) Fresh air mass flow entering the cylinder;

[0117] 17) Density of the mixed gas entering the cylinder; The density of the mixed gas 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 taken when the vehicle is powered on. The default values ​​of the input signal include:

[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 atmospheric pressure read in real time;

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

[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 mixed gas mass flow rate entering the cylinder is the mixed gas mass flow rate entering the cylinder read in real time;

[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 pressure ratio flow coefficient is 1; the throttle pressure ratio flow coefficient is used to calculate the actual effective area of ​​the throttle 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 amount when executing the computer program.

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

[0141] The beneficial effects of the present invention are as follows: 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 amount of intake air entering the cylinder at the moment the intake valve closes is predicted and estimated before the intake valve closes, so as to achieve the setting of the injection amount, 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 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 in the first embodiment of the present invention. DETAILED DESCRIPTION

[0145] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the 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] Embodiment 1:

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

[0148] S1, obtain the input signal of the current sampling period;

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

[0150] S3, determining the density of fresh air entering the cylinder in a future sampling period according to the estimated input signal;

[0151] S4, obtaining the remaining closing time of the intake valve of each cylinder;

[0152] S5. Estimate the instantaneous value of the intake density at the closing time of the intake valve of each cylinder according to 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 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;

[0154] S7. Obtain the fuel injection amount according to 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.

[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, that is, estimating the intake density entering the cylinder in a future period of time, and then reading the remaining time of the intake valve closing, so as to determine the intake density entering the cylinder corresponding to the moment when the intake valve is closed. The acquisition method is also a continuous 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 signal 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 of the engine. For specific input signals, see 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 changes in the air pressure rate 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:

[0165]

[0166] In the formula, dp PreThrottle (z) is dp PreThrottle The value of the previous sampling period. The default value for the first sampling period is 0. PreThrottle (z) is the throttle inlet gas pressure of the previous sampling cycle. 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 changes in the air pressure rate 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:

[0169]

[0170] In the formula, dA ThrottleAct (z) is dA ThrottleAct The value of the previous sampling period. The default value for the first sampling period is 0. 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 2123.7 mm 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 throttle outlet gas pressure p MAP The actual gas pressure at the throttle inlet is 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 gas pressure at throttle outlet p MAP

[0174] 12) Actual gas pressure at throttle outlet p MAP The rate of change of dp MAP In order to avoid the problem of drastic changes in the air pressure rate caused by large air flow 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] In the formula, dp MAP (z) is dp MAP The value of the previous sampling period. The default value for the first sampling period is 0. 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 throttle outlet gas pressure change rate filter time constant, which is 20ms in this example.

[0177] 13) Actual exhaust gas mass flow 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, see the EGR rate calculated in patent CN202310312052.1 "Control method, device, electronic device and storage medium of EGR rate of engine system".

[0179] 15) Gas temperature T at the cylinder inlet port For details, see the target air intake temperature T finally calculated in patent CN202010752089.2 "Engine air intake temperature control method and system".

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

[0181] CN202011247317.7 "Fresh air flow rate into the cylinder prediction method and system" predicts the fresh air flow rate 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 charging 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 default value for the first time is set as follows:

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

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

[0191] 3) The flow rate 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 into the cylinder The default value is the actual mass flow rate of the mixed gas entering the cylinder. When the vehicle is powered on, the mixture contains 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 rate 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 actually read. ThrottleAct .

[0199] 11) Gas mass flow through the throttle The default value is the actual mass flow rate 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 electronic throttle of exhaust gas turbocharged engine" 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 work:

[0207] 1) Update the actual throttle pressure ratio where p MAP According to the acquisition method of (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 of (2.1), p PreThrottle , A ThrottleAct 、T Thr Information 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 of a supercharged direct injection gasoline engine".

[0209] 3) Update the inflation efficiency r VE , calculate the charging efficiency r based on the real-time data signal 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 It is obtained in step 3), and the other signals in this formula are signals 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) Update the coefficients based on the updated information above 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 the 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 pressure ratio flow coefficient Update the gas mass flow through the throttle

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

[0216] 10) Update the mixture density rho entering the cylinder 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 of the current sampling period.

[0218] 12) Update the mass flow of the mixed gas entering the cylinder where rho GasCyl According to item 10), n is the real-time engine speed.

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

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

[0221] 1) Estimate the coefficient r for the next sampling period UseMAP-1 For the specific update method, please refer to 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), and the same applies to the following.

[0222] 2) Estimate the intake pressure change rate dp of the intake manifold 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 change characteristics of the throttle inlet gas pressure of the engine itself, and 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 in this sampling period (not the estimated next sampling period), Δt is the sampling period, 10ms in this example, dp PreThrottleIt is the rate of change of the throttle inlet gas pressure 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 change range of the engine's own throttle effective area change characteristics, while avoiding the phenomenon of the prediction observer failing 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, 10ms in this example, 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 estimated intake pressure change rate dp of the intake manifold in the next sampling period Man-1 is a function of the absolute value of .

[0228]

[0229] The above determination method, on the one hand, avoids that if the intake manifold gas flow correction value is updated greatly when the intake pressure changes greatly, the intake pressure change rate of the intake manifold will be further increased, thereby causing the control to fail to converge; on the other hand, only when the intake pressure changes slightly, the intake manifold gas flow correction value is adjusted to iteratively dynamically adjust and improve the control accuracy of the intake volume. Its calibration method ultimately ensures that the accuracy of the intake volume and the installed intake volume sensor is within ±2%.

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

[0231] Intake 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 change range of the engine's own throttle effective area change characteristics, while avoiding the phenomenon of the prediction observer failing 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 in this sampling cycle (not the estimated next sampling cycle).

[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 is to use 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 It is the actual EGR rate of this sampling cycle (not the estimated next sampling cycle).

[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 respectively 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 to estimate various signals in the next sampling period is to determine the updated various input signals and real-time acquired signals based on the previous sampling period (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 estimated signal of the next sampling period introduced above refers to the estimated signal of 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 worse and worse. This example refers to the signals beyond the seventh subsequent sampling period being the same as the signals of 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 the intake valve of each cylinder to be closed (i.e., the remaining time for the intake valve of cylinder number 1 to be closed is t1, and so on). The engine body design will provide the relationship between the engine crankshaft phase and the cam phase when the VVT ​​is not in action. Then, when the VVT ​​is in action, based on the actual phase of the intake VVT, 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 can be known how many degrees the crankshaft needs to rotate if the intake valve is to be closed. Based on the current engine speed, the remaining time for the intake valve of each cylinder to be closed can be known.

[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 the transient value of the intake density at the time 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 the intake 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 value of intake density rho for 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 to determine 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 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 condition, the transient condition coefficient r Trans is 0, otherwise the transient operating coefficient r Trans Once the throttle is in a stable condition, the transient condition coefficient r Trans Set to 1; however, the transient operating coefficient r Trans The rate of change of reduction is not less than -0.2 / 10ms.

[0252] Based on this, the estimated final value of intake density rho when the intake valve of each cylinder 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 injection amount.

[0254] Embodiment 2:

[0255] The present embodiment provides a computer device, such as a smart phone, tablet computer, laptop computer, desktop computer, rack server, blade server, tower server or cabinet server (including an independent server or a server cluster composed of multiple servers) that can execute programs. The computer device of the present embodiment includes at least but is not limited to: a memory and a processor that can communicate with each other through a system bus.

[0256] In this embodiment, the memory (i.e., readable storage medium) includes flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory, etc.), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM). The memory may also be an external storage device of a computer device, such as a plug-in hard disk, a smart memory card (SmartMedia Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the computer device. Of course, the memory may also include both the internal storage unit of the computer device and its external storage device. In this embodiment, the memory is generally used to store the operating system and various application software installed on the computer device, such as the program code of the method for calculating the injection amount in the first embodiment. In addition, the memory may also be used to temporarily store various data that have been output or are 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 a 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 the first embodiment.

[0258] Embodiment three:

[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, etc.), 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 memory, a disk, an optical disk, a server, an App application store, etc., on which a computer program is stored, and the program realizes corresponding functions when executed by a processor. The computer-readable storage medium of this embodiment is used to store the program code of the fuel injection amount calculation method, and when executed by the processor, the fuel injection amount calculation method in the first embodiment is realized.

[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, and 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 specification 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 the amount of fuel injection, 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 a future sampling period according to the estimated input signal; Get the remaining closing time of each cylinder intake valve; According to the density of fresh air entering the cylinder in the future sampling period and the remaining time of closing 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) The rate of change of the throttle inlet gas pressure 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 opening of throttle valve detected by 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) Actual throttle pressure ratio: The actual throttle 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 outlet gas obtained according to the actual pressure of the throttle 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) Fresh air mass flow entering the cylinder; 17) Density of the mixed gas entering the cylinder; The density of the mixed gas 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 value is defined as the first value taken 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 atmospheric pressure read in real time; 5) The fresh air mass flow rate entering the cylinder is the mixed gas mass flow rate entering the cylinder read in real time; 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 mixed gas mass flow rate entering the cylinder is the mixed gas mass flow rate entering the cylinder read in real time; 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 pressure ratio flow coefficient is 1; the throttle pressure ratio flow coefficient is used to calculate the actual effective area of ​​the throttle 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 comprises: 1) Update the actual throttle pressure ratio according to the actual throttle outlet gas pressure and the throttle inlet gas pressure detected by the sensor; 2) updating the gas mass flow rate flowing through the throttle according to the real-time acquired throttle inlet gas pressure, the actual effective area of ​​the throttle, the throttle inlet gas temperature, and the throttle outlet gas actual pressure; 3) updating the charging efficiency according to the real-time values ​​of all input signals used to calculate the charging efficiency; 4) Update the density of the mixed gas entering the cylinder according to the real-time acquired gas temperature at the inlet port of the cylinder intake valve, the actual gas pressure at the throttle outlet, and the updated charging efficiency; 5) Update the mass flow rate of the mixed gas according to the updated density of the mixed gas entering the cylinder; 6) updating the weighting coefficient according to 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 according to the value of the intake manifold gas flow correction value in the previous sampling period; 7) updating the intake pressure with 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 charging efficiency according to the real-time values ​​of all input signals used to calculate the charging efficiency; 10) updating the density of the mixed gas entering the cylinder according to the real-time acquired gas temperature at the inlet port of the cylinder intake valve, the actual gas pressure at the throttle valve outlet, and the updated charging efficiency; 11) updating the density of fresh air entering the cylinder according to the actual EGR rate obtained in real time and the updated density of the mixed gas entering the cylinder; 12) updating the mass flow rate of the mixed gas according to the updated density of the mixed gas entering the cylinder; 13) Update the fresh air mass flow entering the cylinder according to the updated mixed gas 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 comprises: 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 comprises: 1) According to the updated input signal of the current sampling period and the input signal acquired in real time of the current sampling period, the weighting coefficient and the intake pressure change rate of the next sampling period are estimated; 2) based on the throttle inlet gas pressure and the throttle inlet gas pressure change rate of the current sampling period, the throttle inlet gas pressure of the next sampling period is estimated, and the estimated throttle inlet gas pressure is limited to a set range; 3) According to the actual effective area of ​​the throttle valve and the rate of change of the actual effective area of ​​the throttle valve in the current sampling period, the actual effective area of ​​the throttle valve in the next sampling period is estimated, and the estimated actual effective area of ​​the throttle valve is limited to a set range; 4) estimating a gas flow correction value of the intake manifold in the next sampling period according to the estimated absolute value of the intake pressure change rate of the intake manifold; 5) Based on the estimated intake pressure change rate and the intake pressure obtained in the current sampling period, the intake pressure of the next sampling period is estimated, and the estimated intake pressure is limited to a set range; 6) Estimate the throttle gas flow characteristic parameters, the actual throttle pressure ratio, the throttle pressure ratio flow coefficient, and the gas mass flow rate flowing 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 gas temperature at the intake port of the cylinder intake valve, estimate the density of the mixed gas 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 mixed gas entering the cylinder and the actual EGR rate obtained in real time during the current sampling period, the density of the fresh air entering the cylinder during the next sampling period is estimated; 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 of 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 for sequentially estimating input signals of subsequent sampling periods of the next sampling period comprises: According to the input signal acquired in real time in the previous sampling period and the updated input signal, the input signal in the subsequent sampling period is estimated; 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 according to 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: Determine 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 cylinder is between two adjacent sampling periods, the density of fresh air 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 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 includes: According to the obtained transient operating condition coefficient, the density of fresh air entering the cylinder in the current sampling period, and the transient value of the intake density when the intake valve of each cylinder is closed, the estimated final value of the intake density when the intake valve of each cylinder is closed is estimated.

9. A fuel injection amount calculation device, characterized in that: include: An input signal acquisition module is used to acquire the input signal of the current sampling period; An input signal estimation module is used to estimate the input signal of the future sampling period; A module for determining the density of fresh air entering the cylinder in the future, used 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; An intake density transient value estimation module is used to estimate the intake density transient value of each cylinder at the closing moment of the intake valve according to the fresh air density entering the cylinder in the future sampling period and the remaining closing time of the intake valve of each cylinder; An intake density final value estimation module is used to estimate the intake density final 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 according to 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) The rate of change of the throttle inlet gas pressure 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 opening of throttle valve detected by 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) Actual throttle pressure ratio: The actual throttle 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 outlet gas obtained according to the actual pressure of the throttle 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) Fresh air mass flow entering the cylinder; 17) Density of the mixed gas entering the cylinder; The density of the mixed gas 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 value is defined as the first value taken 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 atmospheric pressure read in real time; 5) The fresh air mass flow rate entering the cylinder is the mixed gas mass flow rate entering the cylinder read in real time; 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 mixed gas mass flow rate entering the cylinder is the mixed gas mass flow rate entering the cylinder read in real time; 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 pressure ratio flow coefficient is 1; the throttle pressure ratio flow coefficient is used to calculate the actual effective area of ​​the throttle 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, characterized in that: When the processor executes the computer program, the steps of the method for calculating the fuel injection amount 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.

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