Engine transient torque calculation method and device, electronic equipment, storage medium and vehicle

Abstract

The invention discloses an engine transient torque calculation method and device, electronic equipment, a storage medium and a vehicle. The method comprises the steps that according to a crank angle, a stroke correction coefficient is calculated based on a stroke correction coefficient function, and the stroke correction coefficient function is a continuous function; the in-cylinder pressure is corrected according to the stroke correction coefficient, and an in-cylinder pressure correction value is obtained; and calculating the instantaneous torque of the engine according to the in-cylinder pressure correction value, the in-cylinder pressure correction value and the reciprocating inertia torque formed on the crankshaft by the inertia of a reciprocating motion part in the engine. Due to the fact that the stroke correction coefficient function is a continuous function, the stroke correction coefficient function can be derived, solving of the engine torque is continuous and derivable, the requirement of a gradient method for continuous derivation is met, optimization of a search solving mode is avoided, the calculation power requirement is reduced, calculation power resources can be saved, and calculation efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle-related technologies, and in particular to a method, device, electronic equipment, storage medium and vehicle for calculating transient torque of an engine. Background Art

[0002] Precise control of the vehicle engine requires determining the engine torque based on the crankshaft angle. For this purpose, the prior art has established an engine torque model to determine the torque corresponding to different crankshaft angles during the stroke.

[0003] However, during the intake and exhaust strokes, the valves open and the cylinder pressure change is no longer an adiabatic compression and expansion process. The existing torque model does not take into account the differences between strokes, and the method of introducing valve opening is also to judge the stroke and obtain the cylinder pressure through conditional judgment. However, obtaining the cylinder pressure through conditional judgment cannot guarantee that the cylinder pressures calculated under different conditions are continuous, and discontinuous cylinder pressure will make the final torque model discontinuous. When calculating the system state through the torque model, due to the discontinuity of the torque model, it is impossible to derive it, and only some optimization search solutions that consume a lot of computing power can be used. Summary of the invention

[0004] Based on this, it is necessary to provide an engine transient torque calculation method, device, electronic device, storage medium and vehicle to address the problem that the torque model in the prior art is discontinuous, which causes excessive computing power consumption in the solution method of engine torque.

[0005] The present invention provides a method for calculating the transient torque of an engine, comprising:

[0006] According to the crankshaft angle, a stroke correction coefficient is calculated based on a stroke correction coefficient function; the stroke correction coefficient represents the influence of the stroke on the cylinder pressure, and the stroke correction coefficient function is a continuous function;

[0007] Correcting the in-cylinder pressure according to the stroke correction coefficient to obtain a correction value of the in-cylinder pressure;

[0008] The instantaneous torque of the engine is calculated based on the cylinder pressure correction value and the reciprocating inertia torque formed on the crankshaft by the inertia of the reciprocating motion components in the engine.

[0009] Further, the correcting the cylinder pressure according to the stroke correction coefficient to obtain a cylinder pressure correction value includes:

[0010] Calculating a throttle opening correction coefficient according to the throttle opening; the throttle opening correction coefficient represents the influence of the throttle opening on the cylinder pressure;

[0011] Calculating the cylinder pressure corresponding to the crankshaft angle according to the crankshaft angle;

[0012] The in-cylinder pressure is corrected according to the stroke correction coefficient and the throttle opening correction coefficient to obtain an in-cylinder pressure correction value.

[0013] Furthermore, the in-cylinder pressure is corrected according to the stroke correction coefficient and the throttle opening correction coefficient to obtain the in-cylinder pressure correction value, including: calculating the in-cylinder pressure correction value as P M,corred =[(P M -P0)·coe s +P0]·coe K , where P M,corred is the cylinder pressure correction value, P M is the cylinder pressure, P0 is the initial cylinder pressure, coe s is the stroke correction factor, coe K is the throttle opening correction coefficient.

[0014] Furthermore, the calculating, according to the crankshaft angle, the cylinder pressure corresponding to the crankshaft angle includes:

[0015] The instantaneous volume in the cylinder is calculated as: Where V is the instantaneous volume in the cylinder, r is the crankshaft radius, L is the connecting rod length, B is the piston diameter, Vc is the clearance volume, and θ is the crankshaft angle;

[0016] The in-cylinder pressure is calculated based on the instantaneous volume in the cylinder as: Among them, P M is the cylinder pressure, P0 is the initial cylinder pressure, V d is the instantaneous effective volume in the cylinder, V d =VV c , γ is the adiabatic index.

[0017] Further, the calculating of the stroke correction coefficient based on the stroke correction coefficient function according to the crankshaft angle includes:

[0018] Substitute the crankshaft angle into the stroke correction coefficient function to obtain the stroke correction coefficient. The stroke correction function is: Among them, coe s is the stroke correction coefficient, C is the adjustment coefficient, and θ is the crankshaft angle.

[0019] Further, the calculation of the instantaneous torque of the engine according to the cylinder pressure correction value and the reciprocating inertia torque formed on the crankshaft by the inertia of the reciprocating motion components in the engine comprises:

[0020] Calculating instantaneous in-cylinder pressure torque according to the in-cylinder pressure correction value and the crankshaft angle;

[0021] Calculating the reciprocating inertia torque on the crankshaft caused by the inertia of the reciprocating parts in the engine according to the engine speed and the crankshaft angle;

[0022] Calculate the friction torque formed by the friction of the engine and the resistance of the accessories driven by the engine;

[0023] The engine instantaneous torque is calculated based on the instantaneous in-cylinder pressure torque, the instantaneous reciprocating inertia torque, and the friction torque.

[0024] Furthermore, the calculating the instantaneous in-cylinder pressure torque according to the in-cylinder pressure correction value and the crankshaft angle includes: calculating the instantaneous in-cylinder pressure torque as: Among them, P M,corred is the cylinder pressure correction value, P0 is the initial cylinder pressure, r is the crankshaft radius, L is the connecting rod length, θ is the crankshaft angle, and A is the piston area.

[0025] Furthermore, the calculation of the reciprocating inertia torque on the crankshaft caused by the inertia of the reciprocating parts in the engine according to the engine speed and the crankshaft angle includes:

[0026] Calculate the instantaneous reciprocating inertia torque as:

[0027] Among them, T r is the instantaneous reciprocating inertia torque, m is the effective mass of the reciprocating inertia force, ω is the angular velocity corresponding to the speed, θ is the crankshaft angle, r is the crankshaft radius, and L is the connecting rod length.

[0028] Furthermore, the calculation of the friction torque formed by the friction force of the engine and the resistance of the accessories driven by the engine includes:

[0029] Calculate the average piston speed corresponding to the rotational speed;

[0030] The friction torque is calculated based on the average piston speed.

[0031] Further:

[0032] The calculating the average piston speed corresponding to the rotational speed includes: calculating the average piston speed corresponding to the rotational speed is Where u is the average piston speed, Tc is a cycle time, B is the piston diameter, dV is the volume differential, dθ is the crank angle differential, and dt is the time differential;

[0033] The calculation of the friction torque according to the average speed of the piston includes: calculating the friction torque function as: T f =D1+D2·P max +D3·u+D4·u 2, where D1 is the first friction torque weight, D2 is the second friction torque weight, D3 is the third friction torque weight, D4 is the fourth friction torque weight, P max is the maximum cylinder pressure, and the first friction torque weight, the second friction torque weight, the third friction torque weight and the fourth friction torque weight are obtained by fitting according to reverse dragging experimental data.

[0034] Furthermore, the calculating the instantaneous torque of the engine according to the instantaneous in-cylinder pressure torque, the instantaneous reciprocating inertia torque and the friction torque comprises:

[0035] Calculate the oil temperature correction coefficient based on the instantaneous oil temperature;

[0036] Calculate the instantaneous torque of a single cylinder as T M =T P +T r -T f ·coe Oil,T , where T M is the instantaneous torque of the single cylinder, T P is the instantaneous cylinder pressure torque, T r is the instantaneous reciprocating inertia torque, T f is the friction torque, coe Oil,T is the oil temperature correction coefficient;

[0037] The single cylinder instantaneous torques of all cylinders of the engine are superimposed to obtain the engine instantaneous torque.

[0038] Furthermore, the oil temperature correction coefficient is calculated according to the instantaneous oil temperature, including:

[0039] Calculate the oil temperature correction factor as: Among them, T Oil is the instantaneous oil temperature, T ref is the standard oil temperature, k is the fitting index, and the fitting index is obtained by fitting the reverse dragging experimental data.

[0040] The present invention provides an engine transient torque calculation device, comprising:

[0041] A stroke correction module, used for calculating a stroke correction coefficient based on a stroke correction coefficient function; the stroke correction coefficient represents the influence of the stroke on the cylinder pressure, and the stroke correction coefficient function is a continuous function;

[0042] An in-cylinder pressure correction module, used to correct the in-cylinder pressure according to the stroke correction coefficient to obtain an in-cylinder pressure correction value;

[0043] The engine instantaneous torque calculation module is used to calculate the engine instantaneous torque according to the cylinder pressure correction value and the reciprocating inertia torque formed on the crankshaft by the inertia of the reciprocating motion parts in the engine.

[0044] The present invention provides an electronic device, comprising:

[0045] at least one processor; and,

[0046] a memory communicatively connected to at least one of the processors; wherein,

[0047] The memory stores instructions that can be executed by at least one of the processors. The instructions are executed by at least one of the processors to enable the at least one of the processors to perform the engine torque modeling method as described above.

[0048] The present invention provides a storage medium, wherein the storage medium stores computer instructions, and when a computer executes the computer instructions, it is used to execute all steps of the engine torque modeling method as described above.

[0049] The present invention provides a vehicle, comprising the engine torque modeling device as described above, or the electronic device as described above.

[0050] The present invention avoids the problem of being unable to be differentiated due to discontinuity caused by conditional judgment, adopts a continuous stroke correction coefficient function to calculate the stroke correction coefficient, and uses the stroke correction coefficient to calculate the instantaneous cylinder pressure torque, and calculates the instantaneous torque of the engine according to the instantaneous cylinder pressure torque. Since the stroke correction coefficient function is a continuous function, the stroke correction coefficient function can be differentiated, and the solution of the engine torque can be continuously differentiated, which meets the requirements of the gradient method for continuous differentiation, avoids optimizing the search solution method, reduces the computing power demand, can save computing power resources, and improves computing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a working flow chart of a method for calculating transient torque of an engine according to an embodiment of the present invention;

[0052] Figure 2 This is a working flow chart of a method for calculating transient torque of an engine according to another embodiment of the present invention;

[0053] Figure 3 This is a schematic diagram of fitting the throttle opening correction coefficient of an example of the present invention;

[0054] Figure 4 This is a schematic diagram of a curve showing the relationship between the average piston speed and the friction torque in one example of the present invention;

[0055] Figure 5 A schematic diagram of an engine torque curve according to an example of the present invention;

[0056] Figure 6 A schematic diagram of an engine transient torque calculation device according to an embodiment of the present invention;

[0057] Figure 7 The figure is a schematic diagram of the hardware structure of an electronic device of the present invention. DETAILED DESCRIPTION

[0058] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. The same components are represented by the same reference numerals. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the accompanying drawings, and the words "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0059] like Figure 1 The figure shows a working flow chart of a method for calculating transient torque of an engine according to an embodiment of the present invention, comprising:

[0060] Step S101, calculating a stroke correction coefficient based on a stroke correction coefficient function according to a crankshaft angle; the stroke correction coefficient represents the influence of the stroke on the cylinder pressure, and the stroke correction coefficient function is a continuous function;

[0061] Step S102, correcting the cylinder pressure according to the stroke correction coefficient to obtain a cylinder pressure correction value;

[0062] Step S103, calculating the instantaneous torque of the engine according to the cylinder pressure correction value and the reciprocating inertia torque formed on the crankshaft by the inertia of the reciprocating parts in the engine.

[0063] Specifically, the present invention can be applied to electronic devices with processing capabilities, such as an electronic control unit (ECU) or an extended domain control unit (XCU) of a vehicle.

[0064] Specifically, the electronic device executes step S101 to perform stroke continuous correction on the cylinder pressure model, and calculates the stroke correction coefficient based on the stroke correction coefficient function according to the crankshaft angle. Since the stroke correction coefficient function is a continuous function, the stroke correction coefficient function can be derived, avoiding the inability to derive due to discontinuity caused by conditional judgment.

[0065] In some embodiments, the stroke correction coefficient function is constructed using a sigmoid function.

[0066] Then, step S102 is executed to correct the cylinder pressure according to the stroke correction coefficient to obtain a cylinder pressure correction value.

[0067] Since the in-cylinder pressure is corrected using the stroke correction coefficient as a parameter, the calculation of the in-cylinder pressure correction value is continuous.

[0068] Specifically, the instantaneous volume in the cylinder can be calculated, and the pressure in the cylinder can be calculated based on the adiabatic process, and then the pressure in the cylinder can be corrected by the stroke correction coefficient and other parameters to obtain a correction value of the pressure in the cylinder.

[0069] Step S103, calculating the instantaneous torque of the engine according to the cylinder pressure correction value and the reciprocating inertia torque formed on the crankshaft by the inertia of the reciprocating parts in the engine.

[0070] Specifically, the reciprocating inertia torque is the torque formed on the crankshaft by the inertia of the reciprocating parts in the engine. The instantaneous torque of the engine at a certain moment can be calculated based on the cylinder pressure correction value and the reciprocating inertia torque formed on the crankshaft by the inertia of the reciprocating parts in the engine.

[0071] In some embodiments, the engine includes multiple cylinders, and the engine torque is obtained by calculating the instantaneous torque of a single cylinder and superimposing the instantaneous torques of the single cylinders of all cylinders.

[0072] For example, if the engine includes four cylinders or six cylinders, the single-cylinder instantaneous torque of each cylinder at a certain moment is calculated respectively, and the single-cylinder instantaneous torques of all cylinders are superimposed to obtain the engine torque at a certain moment.

[0073] More specifically, the crankshaft angle of each cylinder at a certain moment is determined, the corresponding single-cylinder instantaneous torque is calculated, and the single-cylinder instantaneous torques of all cylinders are superimposed to obtain the engine torque at a certain moment. The obtained engine torque can be used for precise control of engine torque shutdown.

[0074] The present invention can use the calculation of the instantaneous torque of the engine based on the stroke correction coefficient function in the scenario where continuous derivation is required, so as to meet the requirement of continuity control and make the torque calculation more accurate.

[0075] The present invention avoids the problem of being unable to be differentiated due to discontinuity caused by conditional judgment, adopts a continuous stroke correction coefficient function to calculate the stroke correction coefficient, and uses the stroke correction coefficient to calculate the instantaneous cylinder pressure torque, and calculates the instantaneous torque of the engine according to the instantaneous cylinder pressure torque. Since the stroke correction coefficient function is a continuous function, the stroke correction coefficient function can be differentiated, and the solution of the engine torque can be continuously differentiated, which meets the requirements of the gradient method for continuous differentiation, avoids optimizing the search solution method, reduces the computing power demand, can save computing power resources, and improves computing efficiency.

[0076] like Figure 2 The flowchart of a method for calculating transient torque of an engine according to another embodiment of the present invention is shown, comprising:

[0077] Step S201, calculating a stroke correction coefficient based on a stroke correction coefficient function according to a crankshaft angle; the stroke correction coefficient represents the influence of the stroke on the cylinder pressure, and the stroke correction coefficient function is a continuous function.

[0078] In one embodiment, the calculating of the stroke correction coefficient based on the stroke correction coefficient function according to the crankshaft angle includes:

[0079] Substitute the crankshaft angle into the stroke correction coefficient function to obtain the stroke correction coefficient. The stroke correction function is: Among them, coe s is the stroke correction coefficient, C is the adjustment coefficient, and θ is the crankshaft angle.

[0080] Step S202, calculating a throttle opening correction coefficient according to the throttle opening; the throttle opening correction coefficient represents the influence of the throttle opening on the cylinder pressure.

[0081] Step S203: Calculate the cylinder pressure corresponding to the crankshaft angle according to the crankshaft angle.

[0082] In one embodiment, calculating the cylinder pressure corresponding to the crankshaft angle according to the crankshaft angle includes:

[0083] The instantaneous volume in the cylinder is calculated as: Where V is the instantaneous volume in the cylinder, r is the crankshaft radius, L is the connecting rod length, B is the piston diameter, Vc is the clearance volume, and θ is the crankshaft angle;

[0084] The in-cylinder pressure is calculated based on the instantaneous volume in the cylinder as: Among them, P M is the cylinder pressure, P0 is the initial cylinder pressure, V d is the instantaneous effective volume in the cylinder, V d =VV c , γ is the adiabatic index.

[0085] Step S204: Correct the cylinder pressure according to the stroke correction coefficient and the throttle opening correction coefficient to obtain a cylinder pressure correction value.

[0086] In one embodiment, the in-cylinder pressure is corrected according to the stroke correction coefficient and the throttle opening correction coefficient to obtain the in-cylinder pressure correction value, including: calculating the in-cylinder pressure correction value as P M,corred =[(P M -P0)·coes +P0]·coe K , where P M,corred is the cylinder pressure correction value, P M is the cylinder pressure, P0 is the initial cylinder pressure, coe s is the stroke correction factor, coe K is the throttle opening correction coefficient.

[0087] Step S205, calculating the instantaneous in-cylinder pressure torque according to the in-cylinder pressure correction value and the crankshaft angle.

[0088] In one embodiment, the calculating the instantaneous in-cylinder pressure torque according to the in-cylinder pressure correction value and the crankshaft angle includes: calculating the instantaneous in-cylinder pressure torque as: Among them, P M,corred is the cylinder pressure correction value, P0 is the initial cylinder pressure, r is the crankshaft radius, L is the connecting rod length, θ is the crankshaft angle, and A is the piston area.

[0089] Step S206: Calculate the reciprocating inertia torque on the crankshaft caused by the inertia of the reciprocating parts in the engine according to the engine speed and the crankshaft angle.

[0090] In one embodiment, the step of calculating the reciprocating inertia torque on the crankshaft caused by the inertia of the reciprocating parts in the engine according to the engine speed and the crankshaft angle includes:

[0091] Calculate the instantaneous reciprocating inertia torque as:

[0092] Among them, T r is the instantaneous reciprocating inertia torque, m is the effective mass of the reciprocating inertia force, ω is the angular velocity corresponding to the speed, θ is the crankshaft angle, r is the crankshaft radius, and L is the connecting rod length.

[0093] Step S207, calculating the friction torque formed by the friction force of the engine and the resistance of the accessories driven by the engine.

[0094] In one embodiment, the calculation of the friction torque formed by the friction force of the engine and the resistance of the accessories driven by the engine includes:

[0095] Calculate the average piston speed corresponding to the rotational speed;

[0096] The friction torque is calculated based on the average piston speed.

[0097] In one embodiment:

[0098] The calculating the average piston speed corresponding to the rotational speed includes: calculating the average piston speed corresponding to the rotational speed is Where u is the average piston speed, Tc is a cycle time, B is the piston diameter, dV is the volume differential, dθ is the crank angle differential, and dt is the time differential;

[0099] The calculating of the friction torque according to the average speed of the piston includes: calculating the friction torque as: T f =D1+D2·P max +D3·u+D4·u 2 , where D1 is the first friction torque weight, D2 is the second friction torque weight, D3 is the third friction torque weight, D4 is the fourth friction torque weight, P max is the maximum cylinder pressure.

[0100] Step S208: calculating the instantaneous engine torque according to the instantaneous in-cylinder pressure torque, the instantaneous reciprocating inertia torque and the friction torque.

[0101] In one embodiment, the calculating the instantaneous torque of the engine according to the instantaneous in-cylinder pressure torque, the instantaneous reciprocating inertia torque and the friction torque comprises:

[0102] Calculate the oil temperature correction coefficient based on the instantaneous oil temperature;

[0103] Calculate the instantaneous torque of a single cylinder as T M =T P +T r -T f ·coe Oil,T , where T M is the instantaneous torque of the single cylinder, T P is the instantaneous cylinder pressure torque, T r is the instantaneous reciprocating inertia torque, T f is the friction torque, coe Oil,T is the oil temperature correction coefficient;

[0104] The single cylinder instantaneous torques of all cylinders of the engine are superimposed to obtain the engine instantaneous torque.

[0105] In one embodiment, the calculating of the oil temperature correction coefficient according to the instantaneous oil temperature includes:

[0106] Calculate the oil temperature correction factor as: Among them, T Oil is the instantaneous oil temperature, T ref is the standard oil temperature, k is the fitting index, and the fitting index is obtained by fitting the reverse dragging experimental data.

[0107] Specifically, firstly, step S201 is executed to calculate the stroke correction coefficient according to the crankshaft angle based on the stroke correction coefficient function; the stroke correction coefficient represents the influence of the stroke on the cylinder pressure, and the stroke correction coefficient function is a continuous function.

[0108] In one embodiment, the calculating of the stroke correction coefficient based on the stroke correction coefficient function according to the crankshaft angle includes:

[0109] Substitute the crankshaft angle into the stroke correction coefficient function to obtain the stroke correction coefficient. The stroke correction function is: Among them, coe s is the stroke correction coefficient, C is the adjustment coefficient, and θ is the crankshaft angle.

[0110] Specifically, the stroke continuous correction is performed on the cylinder pressure model, and the sigmoid function is used to avoid the inability to derive due to discontinuity caused by conditional judgment. Therefore, the stroke correction coefficient is as follows:

[0111]

[0112] Among them, e is a natural constant, the stroke cycle is 720°CA, and it is customary from -180°CA to 540°CA. The stroke sequence is compression-expansion-intake-exhaust. The valve is open during the intake and exhaust strokes, and the pressure in the cylinder does not change much, which can be approximated to atmospheric pressure. In the coefficient calculation formula, C can adjust the steepness of the coefficient change. Preferably, C can be 10.

[0113] This embodiment performs stroke continuous correction on the cylinder pressure model and uses the sigmoid function to avoid the inability to obtain derivatives due to discontinuity caused by conditional judgment.

[0114] Then, step S202 is executed to calculate a throttle opening correction coefficient according to the throttle opening; the throttle opening correction coefficient represents the influence of the throttle opening on the cylinder pressure.

[0115] In one embodiment, the throttle opening correction coefficient is calculated according to the throttle opening, including: calculating the throttle opening correction coefficient as coe K =C1+C2log2(C3K+C4), where coe K is the throttle opening correction coefficient, C1 is the first throttle weight, C2 is the second throttle weight, C3 is the third throttle weight, C4 is the fourth throttle weight, K is the throttle opening, C1, C2, C3, C4 are obtained by fitting based on experimental data. For example, they are obtained by fitting based on the reverse drag experiment data. The reverse drag experiment is an experiment in which the engine is not sprayed with fuel and the generator is used to drive the engine to rotate.

[0116] Where V is the instantaneous volume in the cylinder, Vc is the clearance volume, γ is the adiabatic index, and T0 is the initial cylinder temperature.

[0117] Specifically, this embodiment fits the effect of throttle opening on cylinder pressure according to experimental parameters, takes the maximum pressure ratio as the fitting object, and as the throttle opening increases, the maximum compression pressure has a saturation trend, so the fitting is performed in the form of an ln function, and the fitting formula for constructing the throttle opening correction coefficient function is as follows:

[0118] coe K =C1+C2 log2(C3K+C4) (2)

[0119] According to the reverse drag test data, the maximum in-cylinder pressure ratio corresponding to multiple throttle openings is calculated as the experimental value of the throttle opening correction coefficient, and the constant terms C1-C4 are optimized using the least square method according to the experimental values ​​of multiple throttle openings and the corresponding throttle opening correction coefficients. Among them, the maximum in-cylinder pressure ratio corresponding to the throttle opening is the ratio of the in-cylinder pressure corresponding to the throttle opening to the maximum in-cylinder pressure.

[0120] In some embodiments, according to the reverse drag test data, the maximum in-cylinder pressure ratios corresponding to a plurality of throttle openings are calculated as experimental values ​​of the throttle opening correction coefficients;

[0121] According to the experimental values ​​of multiple throttle openings and the corresponding throttle opening correction coefficients, the throttle opening correction coefficient function is fitted to obtain the fitting value of the first throttle weight, the fitting value of the second throttle weight, the fitting value of the third throttle weight and the fitting value of the fourth throttle weight, and the fitting value of the first throttle weight, the fitting value of the second throttle weight, the fitting value of the third throttle weight and the fitting value of the fourth throttle weight are substituted into the throttle opening correction coefficient function.

[0122] As an example, Figure 3 shown. Figure 3 The horizontal axis is the throttle opening, and the vertical axis is the maximum pressure ratio. It can be seen that the fitted intake coefficient curve 31 obtained by fitting is very close to the actual intake coefficient curve 32 actually measured.

[0123] This embodiment fits the effect of throttle opening on the in-cylinder pressure according to experimental parameters, thereby correcting the in-cylinder pressure based on the throttle opening. At the same time, the throttle opening correction coefficient function is continuous and differentiable. Since the throttle opening correction coefficient is used to correct the in-cylinder pressure, and the in-cylinder pressure correction value is used to calculate the instantaneous in-cylinder pressure torque, the throttle opening correction coefficient function is continuous, which can also ensure the continuity of the calculation of the instantaneous in-cylinder pressure torque.

[0124] Then, step S203 is executed to calculate the cylinder pressure corresponding to the crankshaft angle according to the crankshaft angle.

[0125] In one embodiment, calculating the cylinder pressure corresponding to the crankshaft angle according to the crankshaft angle includes:

[0126] The instantaneous volume in the cylinder is calculated as: Where V is the instantaneous volume in the cylinder, r is the crankshaft radius, L is the connecting rod length, B is the piston diameter, Vc is the clearance volume, and θ is the crankshaft angle;

[0127] The in-cylinder pressure is calculated based on the instantaneous volume in the cylinder as: Among them, P M is the cylinder pressure, P0 is the initial cylinder pressure, V d is the instantaneous effective volume in the cylinder, V d =VV c , γ is the adiabatic index.

[0128] Specifically, the instantaneous volume in the cylinder can be calculated based on the engine structural parameters:

[0129]

[0130] Where r is the crankshaft radius, L is the connecting rod length, B is the piston diameter, V c is the clearance volume.

[0131] Then, the cylinder pressure is calculated based on the adiabatic process

[0132]

[0133] Then, step S204 is executed to correct the in-cylinder pressure according to the stroke correction coefficient and the throttle opening correction coefficient to obtain a correction value of the in-cylinder pressure.

[0134] In one embodiment, the in-cylinder pressure is corrected according to the stroke correction coefficient and the throttle opening correction coefficient to obtain the in-cylinder pressure correction value, including: calculating the in-cylinder pressure correction value as P M,corred =[(P M -P0)·coe s +P0]·coe K , where P M,corred is the cylinder pressure correction value, P M is the cylinder pressure, P0 is the initial cylinder pressure, coe s is the stroke correction factor, coe K is the throttle opening correction coefficient.

[0135] Specifically, the aforementioned stroke correction coefficient and throttle opening correction coefficient are used to correct the in-cylinder pressure respectively, and the in-cylinder pressure correction function is obtained:

[0136] P M,corred =[(P M -P0)·coe s +P0]·coe K (5)

[0137] In this embodiment, the cylinder pressure is calculated using formula (4), the stroke correction coefficient is calculated using formula (1), and the throttle opening correction coefficient is calculated using formula (2). All formulas are continuously differentiable, so the cylinder pressure correction function provided in this embodiment is also continuously differentiable.

[0138] This embodiment realizes the correction of the cylinder pressure through the stroke and the throttle opening.

[0139] Thereafter, step S205 is executed to calculate the instantaneous in-cylinder pressure torque according to the in-cylinder pressure correction value and the crankshaft angle.

[0140] In one embodiment, the calculating the instantaneous in-cylinder pressure torque according to the in-cylinder pressure correction value and the crankshaft angle includes: calculating the instantaneous in-cylinder pressure torque as: Among them, P M,corred is the cylinder pressure correction value, P0 is the initial cylinder pressure, r is the crankshaft radius, L is the connecting rod length, θ is the crankshaft angle, and A is the piston area.

[0141] Specifically, based on the in-cylinder pressure and the force calculation on the connecting rod and crankshaft, the instantaneous in-cylinder pressure torque function is constructed as follows:

[0142]

[0143] Among them, P M,corred is the cylinder pressure correction value, P0 is the initial cylinder pressure, r is the crankshaft radius, L is the connecting rod length, θ is the crankshaft angle, and A is the piston area.

[0144] After calculating the instantaneous cylinder pressure torque, the reciprocating inertia torque formed on the crankshaft by the inertia of the reciprocating parts in the engine is calculated in step S206. The friction torque formed by the friction force of the engine and the resistance of the accessories driven by the engine is calculated in step S207.

[0145] Specifically, the reciprocating inertia torque is the torque formed on the crankshaft by the inertia of the reciprocating parts in the engine. The friction torque is the torque formed by the friction of the engine and the resistance of the accessories driven by the engine, including the water pump, oil pump camshaft, etc.

[0146] In one embodiment, the step of calculating the reciprocating inertia torque on the crankshaft caused by the inertia of the reciprocating parts in the engine according to the engine speed and the crankshaft angle includes:

[0147] Calculate the instantaneous reciprocating inertia torque as:

[0148] Among them, T r is the instantaneous reciprocating inertia torque, m is the effective mass of the reciprocating inertia force, ω is the angular velocity corresponding to the speed, θ is the crankshaft angle, r is the crankshaft radius, and L is the connecting rod length.

[0149] Specifically, the instantaneous reciprocating inertia torque function constructed to calculate the reciprocating inertia force generated by the inertia of the reciprocating parts in the engine is:

[0150]

[0151] Among them, T r is the instantaneous reciprocating inertia torque, m is the effective mass of the reciprocating inertia force, ω is the angular velocity corresponding to the speed, θ is the crankshaft angle, r is the crankshaft radius, and L is the connecting rod length. The calculation formula for ω when the speed is n is as follows:

[0152]

[0153] In one embodiment, the calculation of the friction torque formed by the friction force of the engine and the resistance of the accessories driven by the engine includes:

[0154] Calculate the average piston speed corresponding to the rotational speed;

[0155] The friction torque is calculated based on the average piston speed.

[0156] Specifically, the average piston speed is the average value of the piston speed in one cycle, which corresponds to the rotation speed. Among them, four strokes can be regarded as one cycle. Then, the friction torque is calculated based on the average piston speed.

[0157] In one embodiment:

[0158] The calculating the average piston speed corresponding to the rotational speed includes: calculating the average piston speed corresponding to the rotational speed is Where u is the average piston speed, Tc is a cycle time, B is the piston diameter, dV is the volume differential, dθ is the crank angle differential, and dt is the time differential;

[0159] The calculating of the friction torque according to the average speed of the piston includes: calculating the friction torque as: T f =D1+D2·P max +D3·u+D4·u 2, where D1 is the first friction torque weight, D2 is the second friction torque weight, D3 is the third friction torque weight, D4 is the fourth friction torque weight, P max is the maximum cylinder pressure.

[0160] Specifically, the pressure generated by the piston, connecting rod, water pump, oil pump, and some accessories of the engine will cause friction torque. The friction torque can be fitted based on experimental data, such as reverse drag experimental data. The magnitude of the friction torque takes into account the maximum reverse drag pressure, the first-order term of the piston speed, and the second-order term. Therefore, the friction torque function can be constructed as follows:

[0161] T f =D1+D2·P max +D3·u+D4·u 2 (9)

[0162] Wherein, D1 is the first friction torque weight, D2 is the second friction torque weight, D3 is the third friction torque weight, D4 is the fourth friction torque weight, P max is the maximum cylinder pressure, that is, the highest pressure of reverse dragging. D1, D2, D3, and D4 are obtained by fitting experimental data, for example, by fitting reverse dragging experimental data.

[0163] Among them, u is the average piston speed corresponding to the rotation speed, and the calculation formula is as follows:

[0164]

[0165] Where u is the average speed of the piston, Tc is a cycle time, B is the piston diameter, dV is the volume differential, dθ is the crank angle differential, and dt is the time differential. Specifically, when calculating the average speed of the piston, at the speed n, one cycle can be divided into multiple small times, and each small time is a time differential dt. The volume change within each time differential dt is obtained as the volume differential dV, and the crank angle change is obtained as the crank angle differential dθ. Substitute the corresponding dt, dV, and dθ into formula (10) to obtain the average speed u of the piston corresponding to the speed n.

[0166] Since formula (9) describes the friction torque corresponding to the average piston speed, the average piston speed corresponding to the speed is first calculated according to formula (10), and then formula (9) is fitted according to the reverse drag test data to obtain the fitting values ​​of D1, D2, D3, and D4. It should also be made clear that the average torque of the reverse drag test is the torque of the multi-cylinder as a whole, so the single-cylinder data needs to be averaged according to the number of cylinders. Therefore, the friction torque corresponding to different speeds in the conduction test data is averaged according to the number of cylinders to obtain the friction torque of a single cylinder corresponding to different speeds, and the average piston speed calculated by the speed and the friction torque of a single cylinder corresponding to the same speed are substituted into formula (10), and the fitting values ​​of D1, D2, D3, and D4 are obtained by least squares fitting.

[0167] As an example, Figure 4 shown. Figure 4 The horizontal axis is the average piston speed, and the vertical axis is the pressure corresponding to the friction torque. It can be seen that the fitting pressure curve 41 of the friction torque corresponding pressure obtained by the fitting method of this embodiment is very close to the actual pressure curve 42 of the friction torque corresponding pressure actually measured.

[0168] This embodiment fits the friction torque according to the experimental parameters.

[0169] Finally, step S208 is executed to calculate the instantaneous torque of the engine according to the instantaneous in-cylinder pressure torque, the instantaneous reciprocating inertia torque and the friction torque.

[0170] Specifically, the engine torque is jointly affected by the instantaneous cylinder pressure torque, the instantaneous reciprocating inertia torque and the friction torque. Therefore, a torque model is constructed to calculate the engine instantaneous torque based on the instantaneous cylinder pressure torque, the instantaneous reciprocating inertia torque and the friction torque.

[0171] Since the instantaneous in-cylinder pressure torque function calculated based on the stroke correction coefficient can be continuously differentiated, and the throttle opening correction coefficient function is continuously differentiable, the final engine torque model can also be continuously differentiated.

[0172] In one embodiment, the calculating the instantaneous torque of the engine according to the instantaneous in-cylinder pressure torque, the instantaneous reciprocating inertia torque and the friction torque comprises:

[0173] Calculate the oil temperature correction coefficient based on the instantaneous oil temperature;

[0174] Calculate the instantaneous torque of a single cylinder as T M =T P +T r -T f ·coe Oil,T , where T M is the instantaneous torque of the single cylinder, TP is the instantaneous cylinder pressure torque, T r is the instantaneous reciprocating inertia torque, T f is the friction torque, coe Oil,T is the oil temperature correction coefficient;

[0175] The single cylinder instantaneous torques of all cylinders of the engine are superimposed to obtain the engine instantaneous torque.

[0176] Specifically, among the three torques, the friction torque is greatly affected by the temperature of the lubricating oil, so the friction torque is corrected for oil temperature using the oil temperature correction coefficient.

[0177] At the same time, the engine includes multiple cylinders, and the crankshaft angles of different cylinders differ greatly (for example, 180 degrees). Therefore, the instantaneous torque function of a single cylinder is first constructed: T M =T P +T r -T f ·coe Oil,T (11)

[0178] Among them, T M is the instantaneous torque of the single cylinder, T P is the instantaneous cylinder pressure torque, T r is the instantaneous reciprocating inertia torque, T f is the friction torque, coe Oil,T is the oil temperature correction coefficient.

[0179] Then, the single-cylinder instantaneous torques of all cylinders of the engine are superimposed to obtain a torque model for outputting the instantaneous torque of the engine.

[0180] Specifically, at any moment, the crankshaft angle of each cylinder in the engine is determined at that moment. Under the crankshaft angle condition of each cylinder, the single-cylinder instantaneous torque of each cylinder is calculated by formula (11), and then the single-cylinder instantaneous torques of each cylinder are superimposed to obtain the engine instantaneous torque, that is, the overall torque of the engine.

[0181] This embodiment takes the temperature influence into consideration and introduces an oil temperature correction coefficient to correct the friction torque. By superimposing the single-cylinder instantaneous torques of all cylinders of the engine, a torque model for outputting the engine instantaneous torque is obtained to accurately predict the engine instantaneous torque and facilitate shutdown continuity control.

[0182] In one embodiment, constructing an oil temperature correction coefficient function for calculating the oil temperature correction coefficient according to the instantaneous oil temperature includes:

[0183] The oil temperature correction coefficient function is constructed as: Among them, T Oil is the instantaneous oil temperature, Tref is the standard oil temperature, k is the fitting index, and the fitting index is obtained by fitting the reverse dragging experimental data.

[0184] Specifically, construct the oil temperature correction coefficient function:

[0185]

[0186] Among them, T Oil is the instantaneous oil temperature, in Kelvin temperature, T ref is the standard oil temperature, Kelvin temperature is used, k is the fitting index, and k is obtained by fitting the reverse drag test data. The friction torque at different oil temperatures is obtained from the reverse drag test data, and the ratio of the friction torque at different oil temperatures to the friction torque at the standard temperature is calculated as the measured value of the oil temperature correction coefficient. The measured value of the oil temperature correction coefficient and the corresponding oil temperature are substituted into formula (12) to obtain the fitting index k.

[0187] like Figure 5 The figure shows a schematic diagram of an engine torque curve of an example of the present invention, wherein the horizontal axis is time, unit: s, and the vertical axis is torque, unit: N·m. Figure 5 The test torque curve 51 is a torque curve obtained by calculating the heat release rate based on the cylinder pressure, and the simulation torque curve 52 is a torque curve obtained by the method of this embodiment. Specifically, the torque model of this embodiment is used to obtain the instantaneous torque of the engine at each moment, and then the instantaneous torques of the engine at multiple moments are connected to obtain the simulation torque curve 52. By comparison, it can be seen that after the engine runs stably, the method of this embodiment has a higher accuracy on the basis of obtaining continuity, laying a foundation for continuity control.

[0188] In this embodiment, the stroke cylinder pressure is continuously modeled in a differentiable manner, which enables the gradient method system control to avoid optimizing the search solution method and reduce the computing power requirement. At the same time, the influence of the throttle on the reverse drag torque is introduced in the form of a differentiable model, and the corresponding function is fitted through the reverse drag experimental data. In the torque model that calculates the instantaneous torque of the engine through the instantaneous cylinder pressure torque, the instantaneous reciprocating inertia torque and the friction torque, the temperature effect is considered, and the friction torque is corrected for oil temperature, which can accurately predict the reverse drag torque and facilitate shutdown continuity control.

[0189] Based on the same inventive concept, Figure 6 FIG. 1 is a schematic diagram of an engine transient torque calculation device according to an embodiment of the present invention, comprising:

[0190] A stroke correction module 601 is used to calculate a stroke correction coefficient based on a stroke correction coefficient function; the stroke correction coefficient represents the effect of the stroke on the cylinder pressure, and the stroke correction coefficient function is a continuous function;

[0191] The cylinder pressure correction module 602 is used to correct the cylinder pressure according to the stroke correction coefficient to obtain a cylinder pressure correction value;

[0192] The engine instantaneous torque calculation module 603 is used to calculate the engine instantaneous torque according to the cylinder pressure correction value and the reciprocating inertia torque formed on the crankshaft by the inertia of the reciprocating parts in the engine.

[0193] The present invention avoids the problem of being unable to be differentiated due to discontinuity caused by conditional judgment, adopts a continuous stroke correction coefficient function to calculate the stroke correction coefficient, and uses the stroke correction coefficient to calculate the instantaneous cylinder pressure torque, and calculates the instantaneous torque of the engine according to the instantaneous cylinder pressure torque. Since the stroke correction coefficient function is a continuous function, the stroke correction coefficient function can be differentiated, and the solution of the engine torque can be continuously differentiated, which meets the requirements of the gradient method for continuous differentiation, avoids optimizing the search solution method, reduces the computing power demand, can save computing power resources, and improves computing efficiency.

[0194] In one embodiment, the correcting the cylinder pressure according to the stroke correction coefficient to obtain the cylinder pressure correction value includes:

[0195] Calculating a throttle opening correction coefficient according to the throttle opening; the throttle opening correction coefficient represents the influence of the throttle opening on the cylinder pressure;

[0196] Calculating the cylinder pressure corresponding to the crankshaft angle according to the crankshaft angle;

[0197] The in-cylinder pressure is corrected according to the stroke correction coefficient and the throttle opening correction coefficient to obtain an in-cylinder pressure correction value.

[0198] In one embodiment, the in-cylinder pressure is corrected according to the stroke correction coefficient and the throttle opening correction coefficient to obtain the in-cylinder pressure correction value, including: calculating the in-cylinder pressure correction value as P M,corred =[(P M -P0)·coe s +P0]·coe K , where P M,corred is the cylinder pressure correction value, P M is the cylinder pressure, P0 is the initial cylinder pressure, coe s is the stroke correction factor, coe K is the throttle opening correction coefficient.

[0199] In one embodiment, calculating the cylinder pressure corresponding to the crankshaft angle according to the crankshaft angle includes:

[0200] The instantaneous volume in the cylinder is calculated as: Where V is the instantaneous volume in the cylinder, r is the crankshaft radius, L is the connecting rod length, B is the piston diameter, Vc is the clearance volume, and θ is the crankshaft angle;

[0201] The in-cylinder pressure is calculated based on the instantaneous volume in the cylinder as: Among them, P M is the cylinder pressure, P0 is the initial cylinder pressure, V d is the instantaneous effective volume in the cylinder, V d =VV c , γ is the adiabatic index.

[0202] In one embodiment, the calculating of the stroke correction coefficient based on the stroke correction coefficient function according to the crankshaft angle includes:

[0203] Substitute the crankshaft angle into the stroke correction coefficient function to obtain the stroke correction coefficient. The stroke correction function is: Among them, coe s is the stroke correction coefficient, C is the adjustment coefficient, and θ is the crankshaft angle.

[0204] In one embodiment, the calculating of the instantaneous torque of the engine according to the cylinder pressure correction value and the reciprocating inertia torque formed on the crankshaft by the inertia of the reciprocating parts in the engine comprises:

[0205] Calculating instantaneous in-cylinder pressure torque according to the in-cylinder pressure correction value and the crankshaft angle;

[0206] Calculating the reciprocating inertia torque on the crankshaft caused by the inertia of the reciprocating parts in the engine according to the engine speed and the crankshaft angle;

[0207] Calculate the friction torque formed by the friction of the engine and the resistance of the accessories driven by the engine;

[0208] The engine instantaneous torque is calculated based on the instantaneous in-cylinder pressure torque, the instantaneous reciprocating inertia torque, and the friction torque.

[0209] In one embodiment, the calculating the instantaneous in-cylinder pressure torque according to the in-cylinder pressure correction value and the crankshaft angle includes: calculating the instantaneous in-cylinder pressure torque as: Among them, P M,corred is the cylinder pressure correction value, P0 is the initial cylinder pressure, r is the crankshaft radius, L is the connecting rod length, θ is the crankshaft angle, and A is the piston area.

[0210] In one embodiment, the step of calculating the reciprocating inertia torque on the crankshaft caused by the inertia of the reciprocating parts in the engine according to the engine speed and the crankshaft angle includes:

[0211] Calculate the instantaneous reciprocating inertia torque as:

[0212] Among them, T r is the instantaneous reciprocating inertia torque, m is the effective mass of the reciprocating inertia force, ω is the angular velocity corresponding to the speed, θ is the crankshaft angle, r is the crankshaft radius, and L is the connecting rod length.

[0213] In one embodiment, the calculation of the friction torque formed by the friction force of the engine and the resistance of the accessories driven by the engine includes:

[0214] Calculate the average piston speed corresponding to the rotational speed;

[0215] The friction torque is calculated based on the average piston speed.

[0216] In one embodiment:

[0217] The calculating the average piston speed corresponding to the rotational speed includes: calculating the average piston speed corresponding to the rotational speed is Where u is the average piston speed, Tc is a cycle time, B is the piston diameter, dV is the volume differential, dθ is the crank angle differential, and dt is the time differential;

[0218] The calculation of the friction torque according to the average speed of the piston includes: calculating the friction torque function as: T f =D1+D2·P max +D3·u+D4·u 2 , where D1 is the first friction torque weight, D2 is the second friction torque weight, D3 is the third friction torque weight, D4 is the fourth friction torque weight, P max is the maximum cylinder pressure, and the first friction torque weight, the second friction torque weight, the third friction torque weight and the fourth friction torque weight are obtained by fitting according to reverse dragging experimental data.

[0219] In one embodiment, the calculating the instantaneous torque of the engine according to the instantaneous in-cylinder pressure torque, the instantaneous reciprocating inertia torque and the friction torque comprises:

[0220] Calculate the oil temperature correction coefficient based on the instantaneous oil temperature;

[0221] Calculate the instantaneous torque of a single cylinder as T M =T P +T r -T f ·coe Oil,T , where T M is the instantaneous torque of the single cylinder, T P is the instantaneous cylinder pressure torque, T r is the instantaneous reciprocating inertia torque, Tf is the friction torque, coe Oil,T is the oil temperature correction coefficient;

[0222] The single cylinder instantaneous torques of all cylinders of the engine are superimposed to obtain the engine instantaneous torque.

[0223] In one embodiment, the calculating of the oil temperature correction coefficient according to the instantaneous oil temperature includes:

[0224] Calculate the oil temperature correction factor as: Among them, T Oil is the instantaneous oil temperature, T ref is the standard oil temperature, k is the fitting index, and the fitting index is obtained by fitting the reverse dragging experimental data.

[0225] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0226] like Figure 7 The figure shows a hardware structure diagram of an electronic device of the present invention, including:

[0227] at least one processor 701; and,

[0228] A memory 702 that is communicatively connected to at least one of the processors 701; wherein,

[0229] The memory 702 stores instructions that can be executed by at least one of the processors. The instructions are executed by at least one of the processors to enable the at least one of the processors to perform the engine transient torque calculation method as described above.

[0230] Figure 7 A processor 701 is taken as an example.

[0231] The electronic device may further include: an input device 703 and a display device 704 .

[0232] The processor 701, the memory 702, the input device 703 and the display device 704 may be connected via a bus or other means, and the figure takes the connection via a bus as an example.

[0233] The memory 702 is a non-volatile computer-readable storage medium that can be used to store non-volatile software programs, non-volatile computer executable programs and modules, such as program instructions / modules corresponding to the engine transient torque calculation method in the embodiment of the present application, for example, Figure 1 , Figure 2The processor 701 executes various functional applications and data processing by running the non-volatile software programs, instructions and modules stored in the memory 702, that is, the engine transient torque calculation method in the above embodiment is implemented.

[0234] The memory 702 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required by at least one function; the data storage area may store data created according to the use of the engine transient torque calculation method, etc. In addition, the memory 702 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 702 may optionally include a memory remotely arranged relative to the processor 701, and these remote memories may be connected to a device for executing the engine transient torque calculation method via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0235] The input device 703 can receive user clicks and generate signal inputs related to user settings and function controls of the engine transient torque calculation method. The display device 704 can include display devices such as a display screen.

[0236] The one or more modules are stored in the memory 702 , and when run by the one or more processors 701 , the engine transient torque calculation method in any of the above method embodiments is executed.

[0237] The present invention avoids the problem of being unable to be differentiated due to discontinuity caused by conditional judgment, adopts a continuous stroke correction coefficient function to calculate the stroke correction coefficient, and uses the stroke correction coefficient to calculate the instantaneous cylinder pressure torque, and calculates the instantaneous torque of the engine according to the instantaneous cylinder pressure torque. Since the stroke correction coefficient function is a continuous function, the stroke correction coefficient function can be differentiated, and the solution of the engine torque can be continuously differentiated, which meets the requirements of the gradient method for continuous differentiation, avoids optimizing the search solution method, reduces the computing power demand, can save computing power resources, and improves computing efficiency.

[0238] An embodiment of the present invention provides a storage medium, wherein the storage medium stores computer instructions. When a computer executes the computer instructions, the storage medium is used to execute all steps of the engine transient torque calculation method as described above.

[0239] In the context of the present disclosure, a storage medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or apparatus. The storage medium may be a machine-readable signal medium or a machine-readable storage medium. Alternatively, the storage medium may be a non-temporary computer-readable storage medium, for example, a non-temporary computer-readable storage medium may be a ROM, a random access memory (Random Access Memory, RAM), a compact disc read-only memory (Compact Disc ROM, CD-ROM), a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0240] An embodiment of the present invention provides a vehicle, including the above-mentioned engine transient torque calculation device, or the above-mentioned electronic device. It is understandable that the vehicle may also include: a processor, a memory, and a computer program. The computer program is stored in the memory and is configured to be executed by the processor to implement the engine transient torque calculation method provided in the embodiment of the present disclosure. The processor and the memory are already in Figure 6 The parts described in the illustrated embodiment will not be repeated here.

[0241] An embodiment of the present invention provides an engine torque model, including:

[0242] A stroke correction coefficient function for calculating a stroke correction coefficient according to a crankshaft angle; the stroke correction coefficient represents the influence of the stroke on the cylinder pressure, and the stroke correction coefficient function is a continuous function;

[0243] An in-cylinder pressure correction function for correcting the in-cylinder pressure according to the stroke correction coefficient to obtain an in-cylinder pressure correction value;

[0244] an instantaneous in-cylinder pressure torque function for calculating the instantaneous in-cylinder pressure torque according to the in-cylinder pressure correction value and the crankshaft angle;

[0245] An engine instantaneous torque function is used to calculate the engine instantaneous torque based on the cylinder pressure correction value and the reciprocating inertia torque formed on the crankshaft by the inertia of the reciprocating motion components in the engine.

[0246] Specifically, the stroke correction coefficient function is a function of formula (1), and the stroke correction coefficient function is continuously differentiable.

[0247] The in-cylinder pressure correction function is represented by formula (5). The in-cylinder pressure correction function corrects the in-cylinder pressure according to the stroke correction coefficient and the throttle opening correction coefficient to obtain a in-cylinder pressure correction value.

[0248] In some embodiments, the engine torque model further includes:

[0249] A throttle opening correction coefficient function for calculating a throttle opening correction coefficient according to the throttle opening;

[0250] Volume function for calculating the instantaneous volume in the cylinder;

[0251] An in-cylinder pressure function is used to calculate the in-cylinder pressure based on the instantaneous in-cylinder volume.

[0252] Specifically, the throttle opening correction coefficient function is formula (2), which is also a continuous function. The volume function is formula (3), which calculates the instantaneous volume in the cylinder according to the engine structural parameters. The cylinder pressure function is formula (4), which calculates the cylinder pressure according to the adiabatic process.

[0253] The instantaneous in-cylinder pressure torque function is expressed as formula (6). The instantaneous in-cylinder pressure torque function is constructed based on the in-cylinder pressure and the force calculation on the connecting rod and crankshaft.

[0254] In some embodiments, the engine torque module further includes:

[0255] An instantaneous reciprocating inertia torque function for calculating the reciprocating inertia torque formed on the crankshaft by the inertia of the reciprocating parts in the engine;

[0256] A friction torque function for calculating the friction torque formed by the friction force of the engine and the resistance of the accessories driven by the engine;

[0257] Single cylinder instantaneous torque function used to calculate the instantaneous torque of a single cylinder.

[0258] Among them, the instantaneous reciprocating inertia torque function is formula (7), which is used to calculate the reciprocating inertia torque formed on the crankshaft by the inertia of the reciprocating motion parts in the engine. The friction torque function is formula (9), which is used to calculate the friction torque formed by the friction force of the engine and the resistance of the accessories driven by the engine. The single cylinder instantaneous torque function is formula (11), which is used to calculate the instantaneous torque of a single cylinder.

[0259] The instantaneous torque function of the engine is Among them, T total is the instantaneous torque of the engine, n c is the number of cylinders contained in the engine, T M,i is the instantaneous torque of a single cylinder of the i-th cylinder.

[0260] The engine torque model of this embodiment can be used in the continuous control of the engine. Since the engine torque model is continuously differentiable, it meets the requirement of the gradient method for continuous differentiation. Therefore, based on the engine torque model of this embodiment, the gradient method system control can be enabled to avoid the optimization search solution method and reduce the computing power requirement.

[0261] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for calculating engine transient torque, characterized in that: include: Calculating a stroke correction coefficient based on a stroke correction coefficient function according to the crankshaft angle; The stroke correction coefficient represents the effect of the stroke on the in-cylinder pressure, and the stroke correction coefficient function is a continuous function; Correcting the in-cylinder pressure according to the stroke correction coefficient to obtain a correction value of the in-cylinder pressure; The instantaneous torque of the engine is calculated based on the cylinder pressure correction value and the reciprocating inertia torque generated on the crankshaft by the inertia of the reciprocating motion components in the engine.

2. The method for calculating engine transient torque according to claim 1, characterized in that: The step of correcting the in-cylinder pressure according to the stroke correction coefficient to obtain a corrected value of the in-cylinder pressure includes: Calculating a throttle opening correction coefficient based on the throttle opening; the throttle opening correction coefficient represents the effect of the throttle opening on the cylinder pressure; calculating, based on the crankshaft angle, the in-cylinder pressure corresponding to the crankshaft angle; The in-cylinder pressure is corrected according to the stroke correction coefficient and the throttle opening correction coefficient to obtain an in-cylinder pressure correction value.

3. The method for calculating engine transient torque according to claim 2, characterized in that: The in-cylinder pressure is corrected according to the stroke correction coefficient and the throttle opening correction coefficient to obtain the in-cylinder pressure correction value, including: calculating the in-cylinder pressure correction value as P M,corred =[(P M -P0)·coe s +P0]·coe K , where P M,corred is the cylinder pressure correction value, P M is the cylinder pressure, P0 is the initial cylinder pressure, coe s is the stroke correction coefficient, coe K is the throttle opening correction coefficient.

4. The method for calculating the instantaneous engine torque according to claim 2, characterized in that: Calculating the in-cylinder pressure corresponding to the crankshaft angle according to the crankshaft angle includes: The instantaneous volume in the cylinder is calculated as: Where V is the instantaneous volume in the cylinder, r is the crankshaft radius, L is the connecting rod length, B is the piston diameter, Vc is the clearance volume, and θ is the crankshaft angle; The in-cylinder pressure is calculated based on the instantaneous volume in the cylinder as: Among them, P M is the cylinder pressure, P0 is the initial cylinder pressure, V d is the instantaneous effective volume in the cylinder, V d =VV c , γ is the adiabatic index.

5. The method for calculating engine transient torque according to claim 1, characterized in that: The calculating of the stroke correction coefficient based on the stroke correction coefficient function according to the crankshaft angle includes: Substitute the crankshaft angle into the stroke correction coefficient function to obtain the stroke correction coefficient. The stroke correction function is: Among them, coe s is the stroke correction coefficient, C is the adjustment coefficient, and θ is the crankshaft angle.

6. The method for calculating engine transient torque according to claim 1, characterized in that: The calculating of the instantaneous torque of the engine according to the cylinder pressure correction value and the reciprocating inertia torque generated on the crankshaft by the inertia of the reciprocating motion components in the engine includes: Calculating instantaneous in-cylinder pressure torque according to the in-cylinder pressure correction value and the crankshaft angle; Calculating the reciprocating inertia torque on the crankshaft caused by the inertia of the reciprocating parts in the engine according to the engine speed and the crankshaft angle; Calculate the friction torque generated by the friction of the engine and the resistance of the accessories driven by the engine; The engine instantaneous torque is calculated based on the instantaneous in-cylinder pressure torque, the instantaneous reciprocating inertia torque, and the friction torque.

7. The method for calculating engine transient torque according to claim 6, characterized in that: Calculating the instantaneous in-cylinder pressure torque according to the in-cylinder pressure correction value and the crankshaft angle includes: calculating the instantaneous in-cylinder pressure torque as: Among them, P M,corred is the correction value of the in-cylinder pressure, P0 is the initial in-cylinder pressure, r is the crankshaft radius, L is the connecting rod length, θ is the crankshaft angle, and A is the piston area.

8. The method for calculating engine transient torque according to claim 6, characterized in that: The calculating, based on the engine speed and the crankshaft angle, of the reciprocating inertia torque generated on the crankshaft by the inertia of the reciprocating components in the engine comprises: Calculate the instantaneous reciprocating inertia torque as: Among them, T r is the instantaneous reciprocating inertia torque, m is the effective mass of the reciprocating inertia force, ω is the angular velocity corresponding to the speed, θ is the crankshaft angle, r is the crankshaft radius, and L is the connecting rod length.

9. The method for calculating engine transient torque according to claim 6, characterized in that: The calculation of the friction torque generated by the friction force of the engine and the resistance of the accessories driven by the engine includes: Calculate the average piston speed corresponding to the rotational speed; The friction torque is calculated based on the average piston speed.

10. The method for calculating engine transient torque according to claim 9, characterized in that: The calculation of the average piston speed corresponding to the rotational speed includes: calculating the average piston speed corresponding to the rotational speed as Where u is the average piston speed, Tc is the cycle time, B is the piston diameter, dV is the volume differential, dθ is the crank angle differential, and dt is the time differential; The calculation of the friction torque according to the average speed of the piston includes: calculating the friction torque function as: T f =D1+D2·P max +D3·u+D4·u 2 , where D1 is the first friction torque weight, D2 is the second friction torque weight, D3 is the third friction torque weight, D4 is the fourth friction torque weight, P max is the maximum cylinder pressure, and the first friction torque weight, the second friction torque weight, the third friction torque weight and the fourth friction torque weight are obtained by fitting according to reverse dragging experimental data.

11. The method for calculating engine transient torque according to claim 6, characterized in that: The calculating of the instantaneous engine torque according to the instantaneous in-cylinder pressure torque, the instantaneous reciprocating inertia torque, and the friction torque includes: Calculate the oil temperature correction coefficient based on the instantaneous oil temperature; Calculate the instantaneous torque of a single cylinder as T M =T P +T r -T f ·coe Oil,T , where T M is the instantaneous torque of the single cylinder, T P is the instantaneous in-cylinder pressure torque, T r is the instantaneous reciprocating inertia torque, T f is the friction torque, coe Oil,T is the oil temperature correction coefficient; The instantaneous torque of the single cylinder of all cylinders of the engine is superimposed to obtain the instantaneous torque of the engine.

12. The method for calculating engine transient torque according to claim 11, characterized in that: Calculating the oil temperature correction coefficient based on the instantaneous oil temperature includes: Calculate the oil temperature correction coefficient as: Among them, T Oil is the instantaneous oil temperature, T ref is the standard oil temperature, k is the fitting index, and the fitting index is obtained by fitting the reverse drag test data.

13. An engine transient torque calculation device, characterized in that: include: A stroke correction module, configured to calculate a stroke correction coefficient based on a stroke correction coefficient function; The stroke correction coefficient represents the effect of the stroke on the in-cylinder pressure, and the stroke correction coefficient function is a continuous function; an in-cylinder pressure correction module, configured to correct the in-cylinder pressure according to the stroke correction coefficient to obtain a in-cylinder pressure correction value; The engine instantaneous torque calculation module is used to calculate the engine instantaneous torque according to the cylinder pressure correction value and the reciprocating inertia torque formed on the crankshaft by the inertia of the reciprocating motion components in the engine.

14. An electronic device, characterized in that: include: at least one processor; as well as, a memory communicatively connected to at least one of the processors; wherein, The memory stores instructions that can be executed by at least one processor, and the instructions are executed by at least one processor to enable at least one processor to perform the engine transient torque calculation method according to any one of claims 1 to 12.

15. A storage medium, characterized in that: The storage medium stores computer instructions, and when a computer executes the computer instructions, it is used to execute all steps of the engine transient torque calculation method according to any one of claims 1 to 12.

16. A vehicle, characterized in that: The device comprises the engine transient torque calculation device according to claim 13 or the electronic device according to claim 14.

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