A method and device for determining engine friction power, a storage medium and a vehicle

Abstract

The application discloses a kind of determination method, device, storage medium and car of engine friction power, based on current operating parameter of engine to obtain burst pressure value, based on engine accessory speed and oil temperature to determine engine accessory power consumption and engine pair friction power, to engine speed and engine oil amount are calibrated to obtain burst pressure friction power correction coefficient, according to burst pressure value, engine accessory power consumption, engine pair friction power and burst pressure friction power correction coefficient, obtain engine friction power.The application decomposes engine friction power into engine accessory power consumption and engine pair friction power, while considering the influence of burst pressure value on engine friction power, so it greatly improves the calculation precision and accuracy of engine friction power, so as to be closer to the engine friction power under actual working condition.

Description

Technical Field

[0001] This invention relates to the field of engine friction power technology, and more specifically, to a method, apparatus, storage medium, and automobile for determining engine friction power. Background Technology

[0002] Currently, the engine control unit (ECU) typically defines the engine's drag power in a non-injecting, non-igniting state as the engine friction power.

[0003] However, the in-cylinder pressure of an engine under actual operating conditions differs significantly from that under conditions of no fuel injection and no firing. Under actual operating conditions, the in-cylinder combustion pressure increases substantially, leading to increased pressure at friction pairs such as the piston thrust, connecting rod, and crankshaft. This results in friction forces far greater than those under conditions of no fuel injection and no firing. Therefore, there is a substantial error between the engine friction power determined under conditions of no fuel injection and no firing and the engine friction power under actual operating conditions. Summary of the Invention

[0004] In view of this, the present invention discloses a method, apparatus, storage medium and automobile for determining engine friction power, so as to achieve engine friction power determined under conditions of no fuel injection and no ignition, which is closer to the engine friction power under actual working conditions.

[0005] A method for determining engine friction power, comprising:

[0006] The burst pressure value is obtained based on the current operating parameters of the engine;

[0007] The power consumption of engine accessories and the friction power of engine moving parts are determined based on the engine accessory speed and oil temperature.

[0008] The engine speed and engine oil quantity are calibrated to obtain the burst pressure friction power correction coefficient;

[0009] The engine friction power is obtained based on the burst pressure value, the power consumption of the engine accessories, the friction power of the engine moving parts, and the burst pressure friction power correction coefficient.

[0010] Optionally, obtaining the burst pressure value based on the current engine operating parameters includes:

[0011] The initial burst pressure value is obtained based on the current operating parameters of the engine;

[0012] The initial burst pressure value is corrected using a pressure correction factor to obtain the burst pressure value.

[0013] Optionally, obtaining the initial burst pressure value based on the current operating parameters of the engine includes:

[0014] The engine's current operating parameters and engine constant parameters are obtained. The current operating parameters include: actual intake manifold pressure, actual intake manifold temperature, engine speed, and engine oil temperature. The engine constant parameters include: gas specific heat ratio and piston compression ratio.

[0015] The heat loss coefficient is obtained based on the engine speed and the oil temperature;

[0016] A temperature correction coefficient is obtained based on the actual intake temperature of the intake pipe and the reference intake temperature of the intake pipe;

[0017] The initial burst pressure value is obtained based on the actual intake pressure of the intake pipe, the specific heat ratio of the gas, the piston compression ratio, the heat loss coefficient, and the temperature correction coefficient.

[0018] Optionally, obtaining the heat loss coefficient based on the engine speed and the oil temperature includes:

[0019] Engine drag tests were conducted at different engine speeds and different engine oil temperatures to obtain the actual burst pressure values.

[0020] Based on the actual intake pressure of the intake manifold, the specific heat ratio of the gas, the piston compression ratio, and the temperature correction coefficient, a reference value for the burst pressure is obtained.

[0021] The heat loss coefficient is obtained by quotienting the actual burst pressure value and the burst pressure reference value.

[0022] Optionally, the initial burst pressure value is corrected using a pressure correction factor to obtain the burst pressure value, including:

[0023] Obtain engine fuel injection quantity and injection advance angle;

[0024] The engine fuel injection quantity and the fuel injection advance angle are calibrated to obtain the burst pressure correction coefficient.

[0025] Based on the actual intake pressure and the reference intake pressure of the intake pipe, the intake pressure correction coefficient is obtained;

[0026] The initial explosion pressure value is corrected using the explosion pressure correction coefficient and the intake pressure correction coefficient to obtain the explosion pressure value;

[0027] The pressure correction coefficient includes the burst pressure correction coefficient and the intake pressure correction coefficient.

[0028] Optionally, determining the power consumption of engine accessories and the frictional power of engine moving parts based on engine accessory speed and oil temperature includes:

[0029] The backward drag test of engine components was conducted at different engine accessory speeds and different engine oil temperatures to obtain the backward drag power of the components;

[0030] Based on the speed ratio between the engine speed and the engine accessory speed, the engine accessory speed, the reverse drag power of the component, and the oil temperature, the power consumption of the engine accessory is obtained.

[0031] When the engine is in a non-injection condition, the engine is pulled backward at different engine speeds and different oil temperatures to obtain the backward engine power and maximum cylinder pressure;

[0032] The engine friction torque is obtained based on the power of the reverse engine, the engine speed, and the engine displacement constant;

[0033] The friction coefficient of the engine kinematic pair is obtained based on the engine friction torque and the power consumption of the engine accessories.

[0034] The frictional power of the engine kinematic pair is obtained based on the friction coefficient of the engine kinematic pair, the engine speed, and the engine connecting rod length.

[0035] Optionally, the calibration of engine speed and engine oil quantity to obtain the burst pressure friction power correction coefficient includes:

[0036] When the engine is operating under normal fuel injection and normal firing conditions, the engine cylinder pressure curve and engine crankshaft output power are obtained by testing at different engine speeds and different engine oil quantities.

[0037] The engine indicated pressure is obtained based on the engine in-cylinder pressure curve.

[0038] The engine's average effective pressure is obtained based on the engine crankshaft output power.

[0039] The difference between the engine indicated pressure and the engine average effective pressure is used to obtain the friction power test value under firing conditions.

[0040] Based on the friction power test value under ignition state, the power consumption of the engine accessories, the friction power of the engine moving parts, and the explosion pressure value, the explosion pressure friction power correction coefficient is obtained.

[0041] A device for determining engine friction power, comprising:

[0042] The burst pressure value determination unit is used to obtain the burst pressure value based on the current operating parameters of the engine.

[0043] The power consumption determination unit is used to determine the power consumption of engine accessories and the friction power of engine moving pairs based on engine accessory speed and oil temperature.

[0044] The correction coefficient determination unit is used to calibrate the engine speed and engine oil quantity to obtain the burst pressure friction power correction coefficient;

[0045] The friction power determination unit is used to obtain the engine friction power based on the burst pressure value, the power consumption of the engine accessories, the friction power of the engine moving pair, and the burst pressure friction power correction coefficient.

[0046] A computer-readable storage medium storing at least one instruction that, when executed by a processor, implements the steps of the method described above.

[0047] A vehicle includes a control device, the control device including a memory and a processor;

[0048] The memory is used to store at least one instruction;

[0049] The processor is used to execute the at least one instruction to implement the steps of the method described above.

[0050] As can be seen from the above technical solution, this invention discloses a method, device, storage medium, and automobile for determining engine friction power. Based on the current operating parameters of the engine, the explosion pressure value is obtained. Based on the engine accessory speed and oil temperature, the power consumption of engine accessories and the friction power of engine moving parts are determined. The engine speed and oil quantity are calibrated to obtain an explosion pressure friction power correction coefficient. Based on the explosion pressure value, engine accessory power consumption, engine moving part friction power, and the explosion pressure friction power correction coefficient, the engine friction power is obtained. This invention decomposes engine friction power into engine accessory power consumption and engine moving part friction power, while also considering the influence of the explosion pressure value on engine friction power. Therefore, it greatly improves the precision and accuracy of engine friction power calculation, thus more closely approximating the engine friction power under actual operating conditions. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the published drawings without creative effort.

[0052] Figure 1This is a flowchart of a method for determining engine friction power disclosed in an embodiment of the present invention;

[0053] Figure 2 This is a flowchart of a method for obtaining an initial burst pressure value based on the current operating parameters of an engine, as disclosed in an embodiment of the present invention.

[0054] Figure 3 This is a flowchart of a method for correcting an initial burst pressure value to obtain a burst pressure value using a pressure correction coefficient, as disclosed in an embodiment of the present invention.

[0055] Figure 4 This is a flowchart of a method for determining the power consumption of engine accessories and the frictional power of engine moving pairs based on engine accessory speed and oil temperature, as disclosed in an embodiment of the present invention.

[0056] Figure 5 This is a flowchart of a method for obtaining a burst pressure friction power correction coefficient by calibrating engine speed and engine oil quantity according to an embodiment of the present invention;

[0057] Figure 6 This is a schematic diagram of the structure of an engine friction power determination device disclosed in an embodiment of the present invention;

[0058] Figure 7 This is a schematic diagram of the structure of an electronic device disclosed in an embodiment of the present invention. Detailed Implementation

[0059] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] This invention discloses a method, apparatus, storage medium, and automobile for determining engine friction power. Based on the engine's current operating parameters, the method obtains the burst pressure value. Based on the engine accessory speed and oil temperature, it determines the power consumption of engine accessories and the friction power of engine moving parts. The method calibrates the engine speed and oil level to obtain a correction coefficient for burst pressure and friction power. Based on the burst pressure value, engine accessory power consumption, engine moving part friction power, and the correction coefficient, the engine friction power is obtained. This invention decomposes engine friction power into engine accessory power consumption and engine moving part friction power, while also considering the influence of burst pressure on engine friction power. Therefore, it greatly improves the precision and accuracy of engine friction power calculation, thus more closely approximating the engine friction power under actual operating conditions.

[0061] See Figure 1 The present invention discloses a flowchart of a method for determining engine friction power, the method comprising:

[0062] Step S101: Obtain the burst pressure value based on the current engine operating parameters.

[0063] The current operating parameters of the engine include, but are not limited to, the actual intake pressure of the intake manifold, the actual intake temperature of the intake manifold, the engine speed, and the engine oil temperature.

[0064] In practical applications, the initial burst pressure value is first obtained based on the current operating parameters of the engine, and then the initial burst pressure value is corrected using a pressure correction coefficient to obtain the final burst pressure value.

[0065] The pressure correction factor is obtained through calibration.

[0066] Step S102: Determine the power consumption of engine accessories and the friction power of engine moving parts based on engine accessory speed and oil temperature.

[0067] In practical applications, there is a certain speed ratio between engine speed and engine accessory speed. Therefore, when the engine speed is known, the engine accessory speed can be obtained based on the speed ratio between the engine speed and the engine accessory speed.

[0068] Engine accessories are various auxiliary devices required to ensure the normal operation of the engine, such as pumps, controllers, sensors, actuators, valves, oil filters, etc.

[0069] It should be noted that this invention decomposes engine friction power into engine accessory power consumption and engine moving pair friction power to improve the precision and accuracy of engine friction power calculation.

[0070] Step S103: Calibrate the engine speed and engine oil quantity to obtain the burst pressure friction power correction coefficient.

[0071] Step S104: Obtain the engine friction power based on the burst pressure value, engine accessory power consumption, engine moving pair friction power, and burst pressure friction power correction coefficient.

[0072] Specifically, the engine friction power FMEP is calculated according to the following formula:

[0073] FMEP=FMEP_fujian_Map+FMEP_motion+PFP_FMEP_corr_map*PFP;

[0074] In the formula, FMEP_fujian_Map represents the power consumption of engine accessories, FMEP_motion represents the friction power of engine moving parts, PFP_FMEP_corr_map represents the correction coefficient for the friction power of the burst pressure, and PFP represents the burst pressure value.

[0075] In summary, this invention discloses a method for determining engine friction power. It obtains the burst pressure value based on the engine's current operating parameters, determines the power consumption of engine accessories and the friction power of engine moving parts based on engine accessory speed and oil temperature, calibrates the engine speed and oil quantity to obtain a burst pressure friction power correction coefficient, and obtains the engine friction power based on the burst pressure value, engine accessory power consumption, engine moving part friction power, and the burst pressure friction power correction coefficient. This invention decomposes engine friction power into engine accessory power consumption and engine moving part friction power, while also considering the influence of the burst pressure value on engine friction power. Therefore, it greatly improves the precision and accuracy of engine friction power calculation, thus more closely approximating the engine friction power under actual operating conditions.

[0076] To further optimize the above embodiments, see [link to relevant documentation]. Figure 2 The present invention discloses a flowchart of a method for obtaining an initial burst pressure value based on the current operating parameters of an engine. The method includes:

[0077] Step S201: Obtain the current operating parameters and constant parameters of the engine.

[0078] The engine's current operating parameters include: actual intake manifold pressure, actual intake manifold temperature, engine speed, and engine oil temperature.

[0079] Engine constant parameters include: gas specific heat ratio and piston compression ratio.

[0080] Step S202: Obtain the heat loss coefficient based on engine speed and oil temperature.

[0081] Specifically, 1) Engine drag tests were conducted at different engine speeds and different oil temperatures to obtain the actual burst pressure value.

[0082] In practical applications, after conducting engine drag tests at different engine speeds and different oil temperatures, the cylinder pressure curve can be obtained based on the test results. The horizontal axis of the cylinder pressure curve represents the engine crankshaft angle, and the vertical axis represents the cylinder pressure. The peak value of the cylinder pressure curve is taken as the actual burst pressure value.

[0083] 2) Based on the actual intake pressure of the intake manifold, the specific heat ratio of the gas, the piston compression ratio, and the temperature correction coefficient, the reference value of the burst pressure is obtained.

[0084] Specifically, the burst pressure reference value is obtained according to the following formula:

[0085] PFP_sim=P*CR^γ / T_correction;

[0086] In the formula, PFP_sim represents the burst pressure reference value, P represents the actual intake pressure of the intake manifold, CR represents the piston compression ratio, γ represents the gas specific heat ratio, and T_correction represents the temperature correction coefficient.

[0087] 3) The heat loss coefficient is obtained by quotienting the actual burst pressure value and the burst pressure reference value.

[0088] The formula for calculating the heat loss coefficient is as follows:

[0089] Heat_correction_mp=PFP_test / PFP_sim;

[0090] In the formula, Heat_correction_mp represents the heat loss coefficient, PFP_test represents the actual burst pressure value, and PFP_sim represents the burst pressure reference value.

[0091] Step S203: Obtain the temperature correction coefficient based on the actual intake temperature of the intake pipe and the reference intake temperature of the intake pipe.

[0092] The formula for calculating the temperature correction factor T_correction is as follows:

[0093] T_correction=SQRT(Tref / T);

[0094] In the formula, Tref represents the reference intake temperature of the intake manifold, T represents the actual intake temperature of the intake manifold, and SQRT represents the square root function.

[0095] Step S204: Based on the actual intake pressure of the intake manifold, the specific heat ratio of the gas, the piston compression ratio, the heat loss coefficient, and the temperature correction coefficient, the initial burst pressure value is obtained.

[0096] The formula for calculating the initial burst pressure is as follows:

[0097] PFP_1st=P*CR^γ / T_correction*Heat_correction_mp;

[0098] In the formula, PFP_1st represents the initial burst pressure value, P represents the actual intake pressure of the intake manifold, CR represents the piston compression ratio, γ represents the gas specific heat ratio, T_correction represents the temperature correction coefficient, and Heat_correction_mp represents the heat loss coefficient.

[0099] To further optimize the above embodiments, see [link to relevant documentation]. Figure 3 The present invention discloses a method for correcting an initial burst pressure value using a pressure correction coefficient to obtain a burst pressure value, the method comprising:

[0100] Step S301: Obtain the engine fuel injection quantity and injection advance angle.

[0101] The injection advance angle refers to the crankshaft angle between the piston and top dead center when the injector begins to inject fuel.

[0102] The injection advance angle has a significant impact on the operation of a diesel engine. If the injection advance angle is too large, it will result in a longer standby period, causing the engine to operate roughly. If the injection advance angle is too small, it will result in an excessive delay in the combustion process, a decrease in the maximum pressure value, and thus a significant decrease in the thermal efficiency of the diesel engine.

[0103] The effects of injection advance angle on pressure are as follows: 1. The maximum average pressure in the cylinder increases as the injection time is advanced; 2. As the injection time is advanced, the ignition delay period is lengthened, the amount of fuel evaporation during the ignition delay period increases, and more fuel-air mixture is formed at the moment of ignition. These combustible mixtures burn almost simultaneously during the rapid combustion period, which significantly increases the maximum combustion pressure.

[0104] Step S302: Calibrate the engine fuel injection quantity and injection advance angle to obtain the burst pressure correction coefficient.

[0105] The burst pressure correction coefficient is obtained using the following formula:

[0106] PFP_cor_mp = PB / PFP_1 st ;

[0107] In the formula, PFP_cor_mp represents the burst pressure correction coefficient, PB represents the burst engine value obtained by testing the in-cylinder pressure under different engine injection quantities and different injection advance angles under normal engine operating conditions, and PFP_1 st This represents the initial burst pressure value.

[0108] Step S303: Based on the actual intake pressure of the intake manifold and the reference intake pressure of the intake manifold, obtain the intake pressure correction coefficient.

[0109] The formula for calculating the intake pressure correction coefficient is as follows:

[0110] Int_P_cor=(P_act / P_ref)^(1 / r);

[0111] In the formula, P_act represents the actual intake pressure of the intake manifold, P_ref represents the reference intake pressure of the intake manifold, and r represents the specific heat ratio of the gas.

[0112] Step S304: Correct the initial explosion pressure value using the explosion pressure correction coefficient and the intake pressure correction coefficient to obtain the explosion pressure value.

[0113] The pressure correction factor includes the burst pressure correction factor and the intake pressure correction factor.

[0114] The formula for calculating the burst pressure value is as follows:

[0115] PFP=PFP_1st*PFP_cor_mp*Int_P_cor;

[0116] In the formula, PFP represents the burst pressure value, PFP_1st represents the initial burst pressure value, PFP_cor_mp represents the burst pressure correction coefficient, and Int_P_cor represents the intake pressure correction coefficient.

[0117] In summary, this invention obtains a more accurate burst pressure value by correcting the initial burst pressure value, thereby improving the precision and accuracy of subsequent calculations of engine friction power.

[0118] It should be noted that the present invention decomposes the engine friction power into engine accessory power consumption and engine moving pair friction power.

[0119] Therefore, to further optimize the above embodiments, see [link to relevant documentation]. Figure 4 The present invention discloses a flowchart of a method for determining the power consumption of engine accessories and the frictional power of engine moving pairs based on engine accessory speed and oil temperature. Specifically, step S102 may include:

[0120] Step S401: Conduct backward drag tests on engine components at different engine accessory speeds and different oil temperatures to obtain the backward drag power of the components.

[0121] In practical applications, engine components can be tested for backward dragging at different engine accessory speeds and different oil temperatures on a component test bench to obtain the backward dragging power of the components.

[0122] Step S402: Based on the speed ratio between engine speed and engine accessory speed, engine accessory speed, component reverse power, and oil temperature, obtain the power consumption of engine accessories.

[0123] In practical applications, the power consumption of engine accessories at different engine speeds and different oil temperatures can be obtained based on the speed ratio between engine speed and engine accessory speed, engine accessory speed, component drag power, and oil temperature.

[0124] Step S403: When the engine is in a non-injection condition, the engine is pulled backward at different engine speeds and different oil temperatures to obtain the backward engine power and maximum cylinder pressure.

[0125] Step S404: Obtain the engine friction torque based on the engine power, engine speed, and engine displacement constant.

[0126] Specifically, the engine friction torque is obtained according to the following formula:

[0127] FMEP_eng = (P1*2) / (Vd*N);

[0128] In the formula, FMEP_eng represents the engine friction torque, P1 represents the power of the reverse engine, Vd represents the engine displacement constant, and N represents the engine speed.

[0129] Step S405: Obtain the friction coefficient of the engine moving pair based on the engine friction torque and the power consumption of engine accessories.

[0130] The formula for calculating the friction coefficient of engine moving parts is as follows:

[0131] Friction_corr_mp=(FMEP_eng-0.005*PFP-FMEP_fujian_mp) / (2*L*rpm / 60)

[0132] In the formula, Friction_corr_mp represents the friction coefficient of the engine moving parts, FMEP_eng represents the engine friction torque, PFP represents the burst pressure value, FMEP_fujian_mp represents the power consumption of engine accessories, L represents the engine connecting rod length, and rpm represents the engine speed.

[0133] Step S406: Based on the friction coefficient of the engine kinematic pair, the engine speed, and the engine connecting rod length, obtain the friction power of the engine kinematic pair.

[0134] The formula for calculating the frictional power of the engine's moving parts is as follows:

[0135] FMEP_motion=Friction_corr_mp*2*L*rpm / 60;

[0136] In the formula, FMEP_motion represents the frictional power of the engine moving pair, Friction_corr_mp represents the friction coefficient of the engine moving pair, L represents the length of the engine connecting rod in units, and rpm represents the engine speed.

[0137] For further optimization of the above embodiments, please refer to Figure 5The present invention discloses a method for calibrating engine speed and engine oil quantity to obtain a correction coefficient for burst pressure friction power, specifically step S103 includes:

[0138] Step S501: When the engine is in normal fuel injection and normal firing conditions, the engine cylinder pressure curve and engine crankshaft output power are obtained by testing at different engine speeds and different engine oil quantities.

[0139] Step S502: Obtain the engine indicated pressure based on the engine cylinder pressure curve.

[0140] In practical applications, the engine indicated pressure is obtained by solving the curve integral of the engine cylinder pressure curve.

[0141] Step S503: Obtain the engine's average effective pressure based on the engine crankshaft output power.

[0142] Specifically, the engine mean effective pressure is determined according to the following formula:

[0143] BMEP = (P2*2) / (Vd*N);

[0144] In the formula, BMEP represents the engine mean effective pressure, P2 represents the engine crankshaft output power, Vd represents the engine displacement constant, and N represents the engine speed.

[0145] Step S504: Calculate the difference between the engine indicated pressure and the engine mean effective pressure to obtain the friction power test value under firing conditions.

[0146] The formula for calculating the friction power test value is as follows:

[0147] FMEP = IMEP - BMEP;

[0148] In the formula, FMEP represents the friction power test value, IMEP represents the engine indicated pressure, and BMEP represents the engine mean effective pressure.

[0149] Step S505: Based on the friction power test value under ignition state, engine accessory power consumption, engine moving pair friction power and explosion pressure value, obtain the explosion pressure friction power correction coefficient.

[0150] The formula for calculating the burst pressure friction power correction coefficient is as follows:

[0151] PFP_FMEP_corr_map=(FMEP-FMEP_fujian_Map-FMEP_motion) / PFP;

[0152] In the formula, PFP_FMEP_corr_map represents the burst pressure friction power correction coefficient, FMEP represents the friction power test value, FMEP_fujian_Map represents the power consumption of engine accessories, FMEP_motion represents the friction power of engine moving parts, and PFP represents the burst pressure value.

[0153] In summary, this invention calibrates the engine speed and engine oil quantity to obtain the burst pressure friction power correction coefficient, and uses the burst pressure friction power correction coefficient to correct the engine friction power, thereby improving the calculation precision and accuracy of the engine friction power, and thus more closely approximating the engine friction power under actual working conditions.

[0154] Corresponding to the above method embodiments, the present invention discloses a device for determining engine friction power.

[0155] join Figure 6 A schematic diagram of a device for determining engine friction power disclosed in an embodiment of the present invention is shown. The device includes:

[0156] The burst pressure value determination unit 601 is used to obtain the burst pressure value based on the current operating parameters of the engine.

[0157] The current operating parameters of the engine include, but are not limited to, the actual intake pressure of the intake manifold, the actual intake temperature of the intake manifold, the engine speed, and the engine oil temperature.

[0158] In practical applications, the initial burst pressure value is first obtained based on the current operating parameters of the engine, and then the initial burst pressure value is corrected using a pressure correction coefficient to obtain the final burst pressure value.

[0159] The pressure correction factor is obtained through calibration.

[0160] The power consumption determination unit 602 is used to determine the power consumption of engine accessories and the friction power of engine moving pairs based on the engine accessory speed and oil temperature.

[0161] In practical applications, there is a certain speed ratio between engine speed and engine accessory speed. Therefore, when the engine speed is known, the engine accessory speed can be obtained based on the speed ratio between the engine speed and the engine accessory speed.

[0162] Engine accessories are various auxiliary devices required to ensure the normal operation of the engine, such as pumps, controllers, sensors, actuators, valves, oil filters, etc.

[0163] It should be noted that this invention decomposes engine friction power into engine accessory power consumption and engine moving pair friction power to improve the precision and accuracy of engine friction power calculation.

[0164] The correction coefficient determination unit 603 is used to calibrate the engine speed and engine oil quantity to obtain the burst pressure friction power correction coefficient.

[0165] Friction power determination unit 604 is used to obtain engine friction power based on the burst pressure value, the power consumption of engine accessories, the friction power of engine moving parts, and the burst pressure friction power correction coefficient.

[0166] Specifically, the engine friction power FMEP is calculated according to the following formula:

[0167] FMEP=FMEP_fujian_Map+FMEP_motion+PFP_FMEP_corr_map*PFP;

[0168] In the formula, FMEP_fujian_Map represents the power consumption of engine accessories, FMEP_motion represents the friction power of engine moving parts, PFP_FMEP_corr_map represents the correction coefficient for the friction power of the burst pressure, and PFP represents the burst pressure value.

[0169] In summary, this invention discloses a device for determining engine friction power. It obtains the burst pressure value based on the engine's current operating parameters, determines the power consumption of engine accessories and the friction power of engine moving parts based on engine accessory speed and oil temperature, calibrates the engine speed and oil quantity to obtain a burst pressure friction power correction coefficient, and obtains the engine friction power based on the burst pressure value, engine accessory power consumption, engine moving part friction power, and the burst pressure friction power correction coefficient. This invention decomposes engine friction power into engine accessory power consumption and engine moving part friction power, while also considering the influence of the burst pressure value on engine friction power. Therefore, it greatly improves the precision and accuracy of engine friction power calculation, thus more closely approximating the engine friction power under actual operating conditions.

[0170] To further optimize the above embodiments, the burst pressure value determination unit 601 may specifically include:

[0171] An initial value determination subunit is used to obtain an initial burst pressure value based on the current operating parameters of the engine;

[0172] The engine's current operating parameters include: actual intake manifold pressure, actual intake manifold temperature, engine speed, and engine oil temperature.

[0173] Engine constant parameters include: gas specific heat ratio and piston compression ratio.

[0174] The pressure value correction subunit is used to correct the initial burst pressure value using a pressure correction coefficient to obtain the burst pressure value.

[0175] Specifically, the initial value determination sub-unit can be used for

[0176] The engine's current operating parameters and engine constant parameters are obtained. The current operating parameters include: actual intake manifold pressure, actual intake manifold temperature, engine speed, and engine oil temperature. The engine constant parameters include: gas specific heat ratio and piston compression ratio.

[0177] The heat loss coefficient is obtained based on the engine speed and the oil temperature;

[0178] A temperature correction coefficient is obtained based on the actual intake temperature of the intake pipe and the reference intake temperature of the intake pipe;

[0179] The initial burst pressure value is obtained based on the actual intake pressure of the intake pipe, the specific heat ratio of the gas, the piston compression ratio, the heat loss coefficient, and the temperature correction coefficient.

[0180] The process by which the initial value determination subunit obtains the heat loss coefficient based on engine speed and oil temperature can specifically include:

[0181] Engine drag tests were conducted at different engine speeds and different engine oil temperatures to obtain the actual burst pressure values.

[0182] Based on the actual intake pressure of the intake manifold, the specific heat ratio of the gas, the piston compression ratio, and the temperature correction coefficient, a reference value for the burst pressure is obtained.

[0183] The heat loss coefficient is obtained by quotienting the actual burst pressure value and the burst pressure reference value.

[0184] To further optimize the above embodiments, the pressure value correction subunit can specifically be used for

[0185] Obtain engine fuel injection quantity and injection advance angle;

[0186] The engine fuel injection quantity and the fuel injection advance angle are calibrated to obtain the burst pressure correction coefficient.

[0187] Based on the actual intake pressure and the reference intake pressure of the intake pipe, the intake pressure correction coefficient is obtained;

[0188] The initial explosion pressure value is corrected using the explosion pressure correction coefficient and the intake pressure correction coefficient to obtain the explosion pressure value;

[0189] The pressure correction coefficients include: the burst pressure correction coefficient and the intake pressure correction coefficient.

[0190] The formula for calculating the burst pressure value is as follows:

[0191] PFP=PFP_1st*PFP_cor_mp*Int_P_cor;

[0192] In the formula, PFP represents the burst pressure value, PFP_1st represents the initial burst pressure value, PFP_cor_mp represents the burst pressure correction coefficient, and Int_P_cor represents the intake pressure correction coefficient.

[0193] In summary, this invention obtains a more accurate burst pressure value by correcting the initial burst pressure value, thereby improving the precision and accuracy of subsequent calculations of engine friction power.

[0194] It should be noted that the present invention decomposes the engine friction power into engine accessory power consumption and engine moving pair friction power.

[0195] To further optimize the above embodiments, the power consumption determination unit 602 may specifically include:

[0196] The backward drag power determination subunit is used to conduct backward drag tests on engine components under different engine accessory speeds and different oil temperatures to obtain the backward drag power of the components;

[0197] The accessory power consumption determination subunit is used to obtain the power consumption of the engine accessory based on the speed ratio relationship between the engine speed and the engine accessory speed, the engine accessory speed, the reverse drag power of the component, and the oil temperature;

[0198] The engine back-towing subunit is used to back-tow the engine at different engine speeds and oil temperatures when the engine is not injecting oil, thereby obtaining the back-towing engine power and maximum cylinder pressure.

[0199] The friction torque determination subunit is used to obtain the engine friction torque based on the power of the reverse engine, the engine speed, and the engine displacement constant.

[0200] A secondary friction coefficient determination sub-unit is used to obtain the friction coefficient of the engine kinematic pair based on the engine friction torque and the power consumption of the engine accessories;

[0201] The secondary friction power determination subunit is used to obtain the friction power of the engine kinematic pair based on the friction coefficient of the engine kinematic pair, the engine speed, and the engine connecting rod length.

[0202] To further optimize the above embodiment, the correction coefficient determination unit 603 may specifically include:

[0203] The test subunit is used to test the engine cylinder pressure curve and engine crankshaft output power at different engine speeds and different engine oil quantities when the engine is in normal fuel injection and normal firing conditions.

[0204] The indicated pressure determination subunit is used to obtain the engine indicated pressure based on the engine cylinder pressure curve.

[0205] An effective pressure determination subunit is used to obtain the engine's average effective pressure based on the engine crankshaft output power.

[0206] The power test value determination subunit is used to calculate the difference between the engine indicated pressure and the engine average effective pressure to obtain the friction power test value under the firing state.

[0207] The correction coefficient determination subunit is used to obtain the explosion pressure friction power correction coefficient based on the friction power test value under ignition state, the power consumption of the engine accessory, the friction power of the engine moving pair, and the explosion pressure value.

[0208] In summary, this invention calibrates the engine speed and engine oil quantity to obtain the burst pressure friction power correction coefficient, and uses the burst pressure friction power correction coefficient to correct the engine friction power, thereby improving the calculation precision and accuracy of the engine friction power, and thus more closely approximating the engine friction power under actual working conditions.

[0209] It should be noted that the specific working principles of each component in the device embodiment can be found in the corresponding section of the method embodiment, and will not be repeated here.

[0210] Corresponding to the above method embodiments, the present invention also discloses a computer-readable storage medium that stores at least one instruction, which, when executed by a processor, implements the process shown in the embodiment of the engine friction power determination method.

[0211] In summary, this invention discloses a computer-readable storage medium that obtains the burst pressure value based on the engine's current operating parameters, determines the power consumption of engine accessories and the frictional power of engine moving parts based on engine accessory speed and oil temperature, calibrates the engine speed and oil quantity to obtain a burst pressure frictional power correction coefficient, and obtains the engine frictional power based on the burst pressure value, engine accessory power consumption, engine moving part frictional power, and the burst pressure frictional power correction coefficient. This invention decomposes engine frictional power into engine accessory power consumption and engine moving part frictional power, while also considering the influence of the burst pressure value on engine frictional power. Therefore, it greatly improves the precision and accuracy of engine frictional power calculation, thus more closely approximating the engine frictional power under actual operating conditions.

[0212] Corresponding to the above embodiments, the present invention also discloses an automobile, which includes a control device, such as... Figure 7 As shown, the electronic device may include: a processor 1 and a memory 2;

[0213] The processor 1 and memory 2 communicate with each other via communication bus 3.

[0214] Processor 1, for executing at least one instruction;

[0215] Memory 2 is used to store at least one instruction;

[0216] Processor 1 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention.

[0217] Memory 2 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0218] The processor executes at least one instruction to implement the process shown in the embodiment of the engine friction power determination method.

[0219] In summary, this invention discloses an automobile, which includes a control device. The processor 1 in the control device obtains the burst pressure value based on the current engine operating parameters, determines the power consumption of engine accessories and the frictional power of engine moving parts based on the engine accessory speed and oil temperature, calibrates the engine speed and oil quantity to obtain a burst pressure frictional power correction coefficient, and obtains the engine frictional power based on the burst pressure value, engine accessory power consumption, engine moving part frictional power, and the burst pressure frictional power correction coefficient. This invention decomposes engine frictional power into engine accessory power consumption and engine moving part frictional power, while considering the influence of the burst pressure value on engine frictional power. Therefore, it greatly improves the precision and accuracy of engine frictional power calculation, thus more closely approximating the engine frictional power under actual operating conditions.

[0220] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0221] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0222] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for determining the frictional power of an engine, characterized in that, include: The burst pressure value is obtained based on the current operating parameters of the engine; The power consumption of engine accessories and the friction power of engine moving parts are determined based on the engine accessory speed and oil temperature. The engine speed and engine oil quantity are calibrated to obtain the burst pressure friction power correction coefficient; The engine friction power is obtained based on the burst pressure value, the power consumption of the engine accessories, the friction power of the engine moving parts, and the burst pressure friction power correction coefficient.

2. The determination method according to claim 1, characterized in that, The process of obtaining the burst pressure value based on the current engine operating parameters includes: The initial burst pressure value is obtained based on the current operating parameters of the engine; The initial burst pressure value is corrected using a pressure correction factor to obtain the burst pressure value.

3. The determination method according to claim 2, characterized in that, The process of obtaining the initial burst pressure value based on the current operating parameters of the engine includes: The engine's current operating parameters and engine constant parameters are obtained. The current operating parameters include: actual intake manifold pressure, actual intake manifold temperature, engine speed, and engine oil temperature. The engine constant parameters include: gas specific heat ratio and piston compression ratio. The heat loss coefficient is obtained based on the engine speed and the oil temperature; A temperature correction coefficient is obtained based on the actual intake temperature of the intake pipe and the reference intake temperature of the intake pipe; The initial burst pressure value is obtained based on the actual intake pressure of the intake pipe, the specific heat ratio of the gas, the piston compression ratio, the heat loss coefficient, and the temperature correction coefficient.

4. The determination method according to claim 3, characterized in that, The process of obtaining the heat loss coefficient based on the engine speed and the oil temperature includes: Engine drag tests were conducted at different engine speeds and different engine oil temperatures to obtain the actual burst pressure values. Based on the actual intake pressure of the intake manifold, the specific heat ratio of the gas, the piston compression ratio, and the temperature correction coefficient, a reference value for the burst pressure is obtained. The heat loss coefficient is obtained by quotienting the actual burst pressure value and the burst pressure reference value.

5. The determination method according to claim 2, characterized in that, The initial burst pressure value is corrected using a pressure correction factor to obtain the burst pressure value, including: Obtain engine fuel injection quantity and injection advance angle; The engine fuel injection quantity and the fuel injection advance angle are calibrated to obtain the burst pressure correction coefficient. Based on the actual intake pressure and the reference intake pressure of the intake manifold, the intake pressure correction coefficient is obtained. The initial explosion pressure value is corrected using the explosion pressure correction coefficient and the intake pressure correction coefficient to obtain the explosion pressure value; The pressure correction coefficient includes the burst pressure correction coefficient and the intake pressure correction coefficient.

6. The determination method according to claim 1, characterized in that, The method of determining the power consumption of engine accessories and the frictional power of engine moving parts based on engine accessory speed and oil temperature includes: The backward drag test of engine components was conducted at different engine accessory speeds and different engine oil temperatures to obtain the backward drag power of the components; Based on the speed ratio between the engine speed and the engine accessory speed, the engine accessory speed, the reverse drag power of the component, and the oil temperature, the power consumption of the engine accessory is obtained. When the engine is in a non-injection condition, the engine is pulled backward at different engine speeds and different oil temperatures to obtain the backward engine power and maximum cylinder pressure; The engine friction torque is obtained based on the power of the reverse engine, the engine speed, and the engine displacement constant; The friction coefficient of the engine kinematic pair is obtained based on the engine friction torque and the power consumption of the engine accessories. The frictional power of the engine kinematic pair is obtained based on the friction coefficient of the engine kinematic pair, the engine speed, and the engine connecting rod length.

7. The determination method according to claim 1, characterized in that, The calibration of engine speed and engine oil quantity to obtain the burst pressure friction power correction coefficient includes: When the engine is operating under normal fuel injection and normal firing conditions, the engine cylinder pressure curve and engine crankshaft output power are obtained by testing at different engine speeds and different engine oil quantities. The engine indicated pressure is obtained based on the engine in-cylinder pressure curve. The engine's average effective pressure is obtained based on the engine crankshaft output power. The difference between the engine indicated pressure and the engine average effective pressure is used to obtain the friction power test value under firing conditions. Based on the friction power test value under ignition state, the power consumption of the engine accessories, the friction power of the engine moving parts, and the explosion pressure value, the explosion pressure friction power correction coefficient is obtained.

8. A device for determining the frictional power of an engine, characterized in that, include: The burst pressure value determination unit is used to obtain the burst pressure value based on the current operating parameters of the engine. The power consumption determination unit is used to determine the power consumption of engine accessories and the friction power of engine moving pairs based on engine accessory speed and oil temperature. The correction coefficient determination unit is used to calibrate the engine speed and engine oil quantity to obtain the burst pressure friction power correction coefficient; The friction power determination unit is used to obtain the engine friction power based on the burst pressure value, the power consumption of the engine accessories, the friction power of the engine moving pair, and the burst pressure friction power correction coefficient.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one instruction, which, when executed by a processor, implements the steps of the method as described in any one of claims 1 to 7.

10. A vehicle, comprising a control device, characterized in that, The control device includes a memory and a processor; The memory is used to store at least one instruction; The processor is configured to execute the at least one instruction to implement the steps of the method as described in any one of claims 1 to 7 above.

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