Method for estimating and controlling intake efficiency of an internal combustion engine

Abstract

A method is described for determining the mass of air m trapped in each cylinder 2 of an internal combustion engine 1 comprising a given number of cylinders 2, each cylinder being connected to an intake manifold 4 from which it receives fresh air via an intake valve 5, and to an exhaust manifold 6 into which it introduces exhaust gases resulting from combustion via an exhaust valve 7. At least one intake valve 5 is actuated to vary in a controlled manner the lift H of the intake valve 5. The method provides for determining the value of each quantity of a first set of reference quantities based on a filling model using measured and / or estimated physical quantities, the first set of reference quantities comprising at least an intake pressure P measured inside the intake manifold 4, an engine speed n, a gas mass (OFF) resulting from combustion and present in the cylinder 2 during a previous operating cycle, estimated as a function of the lift H and of the closing delay angle IVC of the intake valve depending on the lift H. The method then provides: based on the aforementioned filling model, determining the effective internal volume V of each cylinder 2 according to the engine speed n, the lift H of the intake valve and the closing delay angle IVC of the intake valve; the method finally provides: based on the aforementioned reference quantities P, V, OFF, determining the air mass m captured in each cylinder 2 according to the first set of reference quantities and the actual volume V in each cylinder 2.

Description

[0001] Technical Background of the Invention

[0002] Application Areas

[0003] The present invention relates to a method for estimating and controlling the intake efficiency of an internal combustion engine by electronic processing.

[0004] In particular, the invention relates to a method for determining an air mass trapped in each cylinder of an internal combustion engine and to a method for controlling and implementing the operation of at least one cylinder of an internal combustion engine.

[0005] Description of the Prior Art

[0006] As is known, an internal combustion engine supercharged by a turbocharger supercharging system comprises a plurality of injectors which inject fuel into respective cylinders, each cylinder being connected to an intake manifold via at least one respective intake valve and to an exhaust manifold via at least one respective exhaust valve.

[0007] The intake manifold receives a gas mixture containing both exhaust gas and fresh air (i.e. air from the external environment through an intake duct), which is equipped with an air filter for the fresh air flow and regulated by a throttle valve. An air flow meter is also arranged along the intake duct, preferably downstream of the air filter.

[0008] The air flow meter is a sensor connected to an electronic control unit and is designed to detect the flow rate of fresh air drawn through an internal combustion engine. The flow rate of fresh air drawn through an internal combustion engine is a very important parameter for engine control, in particular for determining the amount of fuel to be injected into the cylinders in order to obtain a given air-fuel ratio in the exhaust duct downstream of the exhaust manifold.

[0009] However, generally, the air flow meter is a very expensive and also a rather delicate component, because oil vapor and dust may contaminate the air flow meter, thereby changing the reading of the fresh air flow value inhaled by the internal combustion engine.

[0010] Therefore, a need has arisen to determine the fresh air flow rate drawn by an internal combustion engine (ie, the mass captured in each cylinder), possibly avoiding the use of an air flow meter, but maintaining a high degree of accuracy in accordance with the performance requirements of this technical field.

[0011] In this respect, known solutions do not meet the above requirements, in particular in the field of internal combustion engines using VVH (Variable Valve Height) control technology or using VVH and VVT (Variable Valve Timing) technology. Summary of the invention

[0012] The object of the present invention is to provide a method for determining the air mass trapped in each cylinder of an internal combustion engine which allows at least partially to solve the drawbacks described above with reference to the prior art and responds to the above-mentioned needs particularly felt in the considered technical field.

[0013] This object is achieved by the method according to the description of the invention.

[0014] Further embodiments of this method are defined in the description of the invention.

[0015] Another object of the invention is a method for controlling and implementing the operation of at least one cylinder of an internal combustion engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Other features and advantages of the method according to the invention will become apparent in the following description which describes a preferred embodiment by way of illustrative, non-limiting example with reference to the accompanying drawings, in which:

[0017] - Figure 1 Schematically shows a preferred embodiment of an internal combustion engine equipped with an electronic control unit implementing the method according to the invention;

[0018] - Figure 2 Shown in more detail Figure 1 The cylinder of the engine in;

[0019] - Figure 3-5 It is a schematic diagram of the opening and closing rules of the exhaust valve (left curve) and the intake valve (right curve) under the application conditions of VVH lift control only, VVT timing control only, and simultaneous VVH lift control and VVT timing control.

[0020] - Figure 6 Schematically shows Figure 1 The step of intersecting the intake valve and the exhaust valve of the engine;

[0021] - Figure 7 The known law of the trend of the compressibility factor for isentropic flow through an orifice of radius r is shown as a function of the relationship between the pressures after and before the orifice. DETAILED DESCRIPTION

[0022] Before describing the method, for the sake of clarity, the following reference Figure 1 and Figure 2 An example of an engine 1 in which the method according to the invention can be applied is described in a diagrammatic and simplified manner.

[0023] The engine is an internal combustion engine 1 .

[0024] Preferably, such an engine is an internal combustion engine which is supercharged by means of a turbocharger supercharging system.

[0025] The engine comprises a given number of injectors which inject fuel into their respective cylinders 2 (for example four cylinders, preferably arranged in line); usually, a respective injector is provided for each cylinder 2. Each cylinder 2 is connected to an intake manifold 4 via at least one respective intake valve 5 and to an exhaust manifold 6 via at least one respective exhaust valve 7. According to several possible embodiments, the injection may be of the indirect type (wherein each injector is placed in the intake duct connecting the intake manifold to the cylinder, upstream of the respective cylinder), or may be of the direct type (wherein each injector is placed partially inside the cylinder).

[0026] Each cylinder 2 comprises a respective piston 3 which is mechanically connected to a drive shaft 11 by means of a connecting rod for transmitting the forces resulting from the combustion in the cylinder 2 to the drive shaft 11 (in a manner known per se).

[0027] The intake manifold 4 receives a gas mixture comprising exhaust gases and fresh air from the external environment via an intake duct 8, which is preferably provided with an air filter for the fresh air flow and regulated by a throttle valve 12, which is preferably movable between a closed position and a maximum open position. In the solution shown here, no air flow meter is arranged along the intake duct 8.

[0028] The position of each exhaust valve 7 and the position of each intake valve 5 are controlled by, for example, respective camshafts that receive the movement of the drive shaft 11 .

[0029] Preferably, an intercooler is placed along the intake duct 8, which can be integrated into the intake manifold 4 and performs the function of cooling the intake air. An exhaust pipe 9 is connected to the exhaust manifold 6, wherein the exhaust pipe 9 supplies the exhaust gases produced by the combustion to an exhaust system, which discharges the gases produced by the combustion into the atmosphere. The exhaust system generally includes a catalytic converter and a muffler downstream thereof.

[0030] The supercharging system of the internal combustion engine 1 includes a turbocharger provided with a turbine, and a compressor, wherein the turbocharger is arranged along the exhaust pipe 9 to rotate at a high speed under the bias of the exhaust gas discharged from the cylinder 2, and the compressor is arranged along the intake pipe 8 and is mechanically connected to the turbine to be rotationally supplied by the turbine itself, thereby increasing the air pressure in the intake pipe 8.

[0031] In the above description, reference has been made to an internal combustion engine 1 supercharged by a turbocharger. Alternatively, the method of the invention can be advantageously applied to any internal combustion engine. According to another example, the method can be applied to an internal combustion engine supercharged by a dynamic or positive displacement compressor.

[0032] In the internal combustion engine 1 considered here, variable valve height (VVH) control is performed.

[0033] This VVH control is performed by a VVH device or a VVH actuator known per se (for example, of the META or VALVTRONIC type, to mention solutions well known to those skilled in the art). Figure 2 In the figure, it is symbolically represented as a box with reference numeral 50.

[0034] The VVH actuator allows to continuously vary the lift schedule of the intake valve. Typically, each possible lift value H (settable by the VVH actuator) also implies a corresponding value of intake valve opening advance and a corresponding value of intake valve closing delay.

[0035] As will be explained in more detail below, the VVH actuator includes, for example, an intake valve lift shifter that can start from a maximum lift curve and determine a different curve to modify the lift law with a reduced lift H and width, i.e., delay the opening of the intake valve and anticipate its closing. Typically, the variable speed drive of the valve lift works through specific mechanical / geometric characteristics and has a degree of freedom γ corresponding to the position of the variable speed drive / actuator, which corresponds one-to-one to the lift H (γ).

[0036] The internal combustion engine 1 is controlled by an electronic control unit 10 which controls the operation of all the components of the internal combustion engine 1. In particular, the electronic control unit 10 is connected to a plurality of sensors, such as: a sensor measuring the temperature and pressure along the intake duct 8 upstream of the compressor, a sensor measuring the temperature and pressure along the intake duct 8 upstream of the throttle valve 12, a sensor measuring the temperature T and the pressure P of the mixed gas present in the intake manifold 4.

[0037] Furthermore, the electronic control unit 10 may be connected to a sensor which measures the angular position of the drive shaft 11 and thus the rotation speed n of the engine (eg the engine's revolutions per minute, rpm).

[0038] Furthermore, the electronic control unit 10 may be connected to sensors measuring the air-fuel ratio of the exhaust gases upstream of the catalytic converter (e.g. a linear oxygen probe of the UHEGO or UEGO type, which is known per se and need not be described in detail here) and to sensors measuring the intake valve phase and / or the exhaust valve phase.

[0039] exist Figure 2 In the diagram, some of the above sensors are shown diagrammatically as black circles, each named for the variable it can detect.

[0040] The aforementioned “filling model” or calculation model is stored in the electronic control unit 10 , by means of which, in particular, the air mass m captured in each cylinder 2 and the air mass M drawn in by the internal combustion engine 1 are determined (for each cycle). TOT .

[0041] It is worth noting that, as described above, the electronic control unit 10 is operatively connected to all actuators of all engine cylinders (e.g., Figure 2 50, 51, 52 in the figure) and all sensors (e.g. Figure 2 In the reference number P, T, VVti, VVte, H, T EXH ,P EXH These obvious links are not Figure 1 and 2 This makes the description of other aspects clearer.

[0042] refer to Figure 1-7 Now, a method for determining the air mass m trapped in each cylinder 2 of an internal combustion engine 1 comprising a plurality of cylinders 2 is described. Each cylinder 2 is connected to an intake manifold 4 from which it receives fresh air through at least one corresponding intake valve 5 and to an exhaust manifold 6 from which it introduces exhaust gas resulting from combustion through at least one corresponding exhaust valve 7. At least one intake valve 5 is driven to vary the lift H of the intake valve 5 in a controlled manner.

[0043] The method first comprises the following steps: Based on a population model using measured and / or estimated physical quantities, a value for each quantity of a first set of reference quantities is determined.

[0044] Such a first set of reference quantities includes: the intake pressure P measured inside the intake manifold 4; and the engine speed n; the gas mass (OFF) produced by combustion in the previous operating cycle and present in the cylinder 2, which is estimated based on the above-mentioned lift H and the closing delay angle IVC of the intake valve depending on the above-mentioned lift H.

[0045] The method then provides, based on the above-mentioned filling model, for determining the actual internal volume V of each cylinder 2 as a function of said engine speed n, said lift H of the intake valve and said closing delay angle IVC of the intake valve.

[0046] The method finally determines the air mass m trapped in each cylinder 2 from the first set of reference quantities and the actual volume V inside each cylinder 2 by means of the following relationship:

[0047] m=(P*V)–OFF[1]

[0048] According to a preferred embodiment, the above-mentioned “filling model” or calculation model is stored in the electronic control unit 10 , which model notably allows determining (for each cycle) the air mass m trapped in each cylinder 2 .

[0049] According to the embodiment (in Figure 3 ), the method further comprises the following steps: driving the intake valve 5 in a controlled manner by changing the lift law of the intake valve with the aid of an intake valve lift shifter 50 so as to define the lift H and the opening advance angle IVO and closing delay angle IVC of the intake valve according to a single degree of freedom γ.

[0050] According to the implementation of this embodiment, the driving step includes determining the intake valve opening advance angle IVO by the following relationship:

[0051] IVO(H)=IVO hmax -Δivo(H)[2]

[0052] IVO hmax is the maximum lift (at Figure 3 Indicated as H max ) is the intake valve opening advance angle of the controlled lift H, and Δivo(H) is the change in the intake valve opening advance angle depending on the controlled lift H.

[0053] In addition, the above-mentioned driving step includes determining the intake valve closing delay angle IVC by the following relationship:

[0054] IVC(H)=IVC hmax -Δivc(H)[3]

[0055] IVC hmax is the maximum lift H max , and Δivc(H) is the change in the intake valve closing delay angle depending on the controlled lift H.

[0056] The above-mentioned quantities (IVO(H), IVC(H), Δivo(H), Δivc(H)) that depend on the lift H also depend on the above-mentioned degree of freedom γ, because, as mentioned above, H depends on γ.

[0057] exist Figure 3 , reference characters "bdc" and "tdc" indicate a bottom dead center and a top dead center, respectively.

[0058] According to an embodiment, the degree of freedom γ is related to the position of the VVH actuator.

[0059] According to the embodiment, the method is applied to the internal combustion engine 1 which also performs variable valve timing (VVT) control. Therefore, the embodiment works in the case where both VVH and VVT control exist.

[0060] In this case, the intake valve 5 and / or the exhaust valve 7 are driven by a VVT device, or a VVT actuator, or a VVT phase shifter, which acts on the shaft driving the intake valve 5 and / or the exhaust valve 7, for example, in a hydraulic manner to modify the timing relative to the drive shaft.

[0061] In particular, according to an embodiment of the method considered here, at least one intake valve 5 is further actuated to vary the intake valve angle displacement VVTi in a controlled manner, and / or at least one exhaust valve 7 is actuated to vary the exhaust valve angle displacement VVTe in a controlled manner.

[0062] The step of determining the values ​​of the first set of reference quantities includes determining a closing delay angle IVC of the intake valve based on both the lift H of the intake valve and the displacement VVTi of the intake valve.

[0063] In this specification, the term "VVTi intake valve displacement (or displacement angle)" is used to indicate the angular amplitude of the deviation (relative to an intake valve reference value corresponding to zero VVTi), which is equal to the change in the angular position of the VVTi intake actuator (relative to the engine (crank) angle).

[0064] Similarly, the term "VVTi exhaust valve displacement (or displacement angle)" is used to denote the angular magnitude of the deviation (relative to an exhaust valve reference value corresponding to zero VVTe), equal to the change in angular position of the VVTe exhaust actuator (relative to engine (crank) angle).

[0065] Thus, as mentioned above, displacement refers to the change in position of the VVT ​​actuator.

[0066] According to the implementation mode of this embodiment, the method also includes the following steps: driving the intake valve 5 in a controlled manner by changing the displacement VVTi of the intake valve with the aid of the intake valve phase shifter 51, so that the intake valve opening advance angle IVO and the intake valve closing delay angle IVC both depend not only on the lift H but also on the displacement VVTi of the intake valve; and driving the exhaust valve 7 in a controlled manner by changing the exhaust valve displacement VVTe with the aid of the exhaust valve phase shifter 52, so that the exhaust valve opening advance angle EVO and the exhaust valve closing delay angle EVC both depend on the displacement VVTe of the exhaust valve timing.

[0067] In more detail, the above-mentioned driving step includes determining the intake valve opening advance angle IVO by the following relationship:

[0068] IVO(H)=IVO ref -Δivo(H)–VVTi[4]

[0069] IVO refis the reference value of the intake valve opening advance angle without phase shift, and VVTi is the intake valve phase shifter 51 relative to the reference value IVO ref The displacement angle of the corresponding reference position.

[0070] The driving step further includes determining the closing delay angle IVC of the intake valve by means of the following relationship:

[0071] IVC(H)=IVC ref -Δivc(H)+VVTi[5]

[0072] IVC ref It is the reference value of the closing delay angle of the intake valve without phase shift.

[0073] The driving step further includes determining the exhaust intake valve opening delay angle EVO by the following relationship:

[0074] EVO=EVO ref –VVTe[6]

[0075] EVO ref is the reference value of the exhaust valve opening advance angle without phase shift, and VVTe is the exhaust valve phase shifter 52 relative to the reference value EVO ref Represents the displacement angle of the corresponding reference position.

[0076] The driving step further includes determining the exhaust valve closing delay angle EVC by means of the following relationship:

[0077] EVC=EVC ref +VVTe[7]

[0078] EVC ref It is the reference value of the exhaust valve closing delay angle without phase shift.

[0079] Since the VVT ​​control changes the timing of the intake valve 5 and its intersection with the exhaust valve 7 (the intersection step is a step during which the intake valve 5 and the exhaust valve 7 are opened at the same time), the filling model should also include the following: knowledge of the above parameters. These parameters (relative to the top dead center TDC and the bottom dead center BDC) Figure 4 The summary is as follows:

[0080] IVCref reference closing angle of intake valve 5;

[0081] IVOref reference opening angle of intake valve 5;

[0082] EVCref reference closing angle of exhaust valve 7;

[0083] EVOref: reference opening angle of exhaust valve 7;

[0084] IVC: closing delay angle of intake valve 5;

[0085] IVO is the opening advance angle of intake valve 5;

[0086] Closing delay angle of EVC exhaust valve 7;

[0087] EVO Exhaust valve 7 opening advance angle.

[0088] As mentioned before, the displacement angles VVTi and VVTe can also be defined as:

[0089] VVTi: angular width of the opening or closing deviation relative to the reference value of the intake valve 5, equal to the phase change of the intake actuator VVT;

[0090] VVTe: The angular width of the opening or closing deviation relative to the reference value of the exhaust valve 7, which is equal to the phase change of the exhaust actuator VVT.

[0091] The combined operation of VVT and VVH control and the corresponding parameters are as follows Figure 5 shown.

[0092] Consider now the step of determining the actual internal volume V of the cylinder 2. It is worth noting that this volume V varies geometrically as a function of the closing delay angle IVC of the corresponding intake valve: V=f(IVC). In fact, the actual internal volume V of the cylinder 2 is determined by the combustion chamber V of the cylinder 2. CC The volume V swept by the corresponding piston 3 until the corresponding intake valve 5 is closed c (i.e. the rotation angle of the crank relative to the top dead center PMS) is obtained by summing them up.

[0093] The law of motion for calculating the effective internal volume V of the cylinder 2 at the crank angle α is given below, without providing further details (because it is well known in the literature): V(α)=V CC +V C (α), when V C After (α) is clarified, it becomes:

[0094] V(α)=VCC+S*r*[(1+1 / λ)*(1-(δ / (1+λ) 2 ) 1 / 2 -cosα-1 / λ*(1-(λ*senα-δ) 2 ) 1 / 2 ][8]

[0095] Where V is the actual internal volume of the cylinder; V CCis the volume of the cylinder combustion chamber; α is the rotation angle of the crank relative to the top dead center PMS; r is the crank radius; L is the length of the connecting rod; S is the surface of the piston; d is the offset between the cylinder axis and the drive shaft rotation axis; λ represents the ratio r / L; δ represents the ratio d / L.

[0096] Typically, the volume used for cylinder filling calculation is a function of the intake valve closing delay angle IVC, the intake valve lift H, the engine speed n, and the intake pressure P.

[0097] Applicants have determined the following based on experiments and calculations to express the above correlation (defined in a very general way that is not very operationally useful) in a more efficient way, such as to constitute a good approximation and allow for simpler model calibration.

[0098] According to an embodiment of the method, the step of determining the actual internal volume V of each cylinder comprises, by means of a first mapping f v (IVC,n), the second mapping f h (H,n) and the third mapping f p (P,n) Calculate the actual internal volume V of each cylinder 2.

[0099] The first mapping f v (IVC,n) is a function of the closing delay angle IVC of the intake valve and the engine speed n.

[0100] The second mapping f h (H,n) is a function of the intake valve lift H and the engine speed n.

[0101] The third mapping f p (P,n) is a function of the intake pressure P and the engine speed n.

[0102] According to a more specific embodiment, the actual internal volume V of each cylinder 2 is calculated by the following relationship:

[0103] V=f v (IVC,n)*f h (H,n)*f p (P,n)[9]

[0104] It should be noted that, according to one embodiment, the actual volume V (which may also be defined as the "effective volume V") calculated and used in the method incorporates a dimensional constant that makes the product P*V dimensionally correspond to mass. In other words, the actual volume V is expressed in volume units (e.g. cm 3 ) is the product of a measured volume and a dimensional constant, whose value is considered in a consistent manner in all formulas used.

[0105] Consider now a further possible improvement to the calculation of the air mass trapped in the cylinder which also takes into account the temperature parameter.

[0106] According to an embodiment of the method, the first set of reference quantities also includes the temperature T detected in the intake manifold 4 and the engine coolant temperature T H2O .

[0107] The step of determining the mass m of air trapped in each cylinder 2 comprises calculating the mass m of air trapped in each cylinder 2 from the first set of reference quantities and the actual volume V in each cylinder 2 by means of the following relationship:

[0108] m=[(P*V)–OFF]*f1(T,P)*f2(T H2O ,P)

[10]

[0109] Where f1(T,P) and f2(T H2O ,P) is a known function belonging to the above filling model.

[0110] The above embodiments are based on the following considerations. The filling model starts from the well-known ideal gas law, from which it can be derived that:

[0111] m=(P*V) / (R*T)

[11]

[0112] Wherein P is the average pressure measured in the intake manifold for the engine cycle; T is the temperature of the fresh air and / or exhaust gas mixture in the intake manifold 4; R is the gas constant, which is equal to 287 [J / kg*K] for an ideal gas; V is the internal volume of the cylinder when the corresponding intake valve 5 and exhaust valve 7 are closed.

[0113] The ideal gas law

[11] is experimentally applied to the filling model by incorporating a constant R for the fresh air and / or exhaust gas mixture, so that the air mass m captured in each cylinder 2 for each cycle is expressed as: m = P*V*f1(T,P)*f2(T H2O ,P), where T H2O is the temperature of the engine 1 , that is, the temperature of the coolant of the engine 1 .

[0114] Then, for the filling model, the ideal gas law is further adjusted experimentally so that the calculation of the air mass m captured in each cylinder 2 for each cycle takes into account the gases produced by combustion in the previous working cycle and present in the cylinder (because they do not escape from the cylinder 2 itself or because they are sucked back into the cylinder), thus obtaining the above formula

[10] , where OFF is a variable (mass) that takes into account the gases produced by combustion in the previous working cycle and present in the cylinder 2.

[0115] The experiment was carried out at temperatures T and T H2O For example, the reference temperature T can be selected as 40°C and the temperature T H2O This can be chosen to be 90° C. At this reference temperature (used for calibration), the above functions f1 and f2 assume the value 1.

[0116] Embodiments of methods applicable to engines capable of operating under internal exhaust gas recirculation (EGRi) and / or exhaust gas removal conditions are described below. Such operating conditions are known, as are devices and features (not further described here) that allow internal combustion engines to operate under the above conditions.

[0117] It has to be taken into account that at the beginning of the intake phase of any engine cycle, there are still residual combustion gases from the previous engine cycle in the cylinder 2 .

[0118] Geometrically, the volume occupied by residual combustion gases from the previous engine cycle (i.e., the "dead volume") can be expressed as the nominal geometric volume of the cylinder combustion chamber and the volume V swept inside the cylinder by the corresponding piston. C The sum.

[0119] This “dead volume” is a type of “actual combustion chamber volume” and for simplicity is referred to below as “combustion chamber volume V CC From a geometric point of view, such a volume can be related to the rotation angle of the crank α using the above formula [8].

[0120] Depending on the possible operating conditions, the volume V swept by the piston 3 inside the cylinder 2 is C is variable and can be described by the parameter TVC, which will be better explained later.

[0121] In particular, according to different possible variants, the volume V swept by the piston inside the cylinder C The corresponding ones are as follows:

[0122] - if the intake valve 5 opens after the exhaust valve 7 has closed, the volume swept by the piston until the moment of closing of the exhaust valve 7; or

[0123] - if the exhaust valve 7 is closed after the inlet valve 5 has opened, the volume swept by the piston until the moment of opening of the inlet valve 5 is reached; or

[0124] - if the opening moment of the intake valve 5 is earlier than the top dead center PMS, it corresponds to the volume swept by the piston until the top dead center PMS; in this case, the volume swept by the piston in the cylinder V C is zero, and the actual internal volume V of the cylinder corresponds exactly to the volume V of the combustion chamber of the cylinderCC .

[0125] Given the above possibilities, the parameter TVC may alternatively correspond to different values ​​(different angles), as described below.

[0126] According to one embodiment, applicable to the following situation, wherein: the engine 1 is operated under the internal exhaust gas recirculation condition EGRi, the method comprises the further step of: based on the fourth mapping f e (TVC,n), the fifth map ge(OVL,n) and the sixth map he(H,n) calculate the volume V of the combustion chamber of cylinder 2 cc (i.e. the volume V occupied by the residual combustion gases from the previous engine cycle cc ), the fourth mapping f e (TVC,n) is a function of the first TVC parameter and the engine speed n, the fifth map ge(OVL,n) is a function of the second parameter OVL and the engine speed n, and the sixth map he(H,n) is a function of the lift H and the engine speed n.

[0127] Alternatively, the above first parameter TVC is equal to the closing delay angle EVC of the exhaust valve 7, or equal to the maximum value between zero and the minimum value between the closing delay angle EVC of the exhaust valve 7 and the opening advance angle IVO of the intake valve 5 multiplied by -1.

[0128] The aforementioned second parameter OVL represents the duration of the intersection step between the intake and exhaust curves (where the intake and exhaust valves are simultaneously open), and is defined as the sum of the exhaust valve closing delay angle EVC and the intake valve opening advance angle IVO.

[0129] Parameter OVL such as Figure 6 shown.

[0130] According to a more specific embodiment, the above-mentioned volume V of the combustion chamber cc Use the following formula to calculate:

[0131] V cc =f e (TVC,n)*g e (OVL,n)*h e (H,n)

[12]

[0132] where f e ,g e ,h e is a known function belonging to the above filling model.

[0133] According to another embodiment, applicable to the following situation: wherein the engine 1 is configured to operate under a SCAV condition where the intake pressure is greater than the exhaust pressure, thereby causing fresh air intake to carry away residual exhaust gas in the combustion chamber, the method further comprises the following steps: based on the fourth mapping f s (TVC,n), the fifth mapping g s (OVL,n) and the sixth mapping h s (H,n) Calculate the volume V of the combustion chamber of cylinder 2 cc , the fourth mapping f s (TVC,n) is a function of the first parameter TVC and the engine speed n. The fifth mapping g s (OVL,n) is a function of the second parameter OVL and the engine speed n, and the sixth map h s (H,n) is a function of lift H and engine speed n.

[0134] In this case, the aforementioned first parameter TVC may alternatively be equal to the closing delay angle EVC of the exhaust valve 7, or equal to the maximum value between zero and the minimum value between the closing delay angle EVC of the exhaust valve 7 and the opening advance angle IVO of the intake valve 5 multiplied by -1.

[0135] In this case, the above second parameter OVL represents the duration of the intersection step between the intake and exhaust curves and is defined as the sum of the exhaust valve closing delay angle EVC and the intake valve opening advance angle EVC, ie OVL=EVC+IVO.

[0136] According to a more specific embodiment, the above-mentioned volume V of the combustion chamber cc Use the following formula to calculate:

[0137] V cc =f s (TVC,n)*g s (OVL,n)*h s (H,n)

[13]

[0138] where f s ,g s ,h s is a known function belonging to the above filling model.

[0139] According to another embodiment, the method provides the further step of calculating the mass M of the gas flow flowing through the intersection step (ie through the intake valve 5 and the exhaust valve 7) in the case of internal exhaust gas recirculation EGRi or exhaust gas removal SCAV based on the following relationship OVL :

[0140] M OVL =PERM*β(P / P0,n)*P0 / P0_REF *(T 0_REF / T0) 1 / 2 / n

[14]

[0141] Where PERM is the hydraulic permeability at the intersection point; n is the engine speed; P 0_REF is the reference pressure upstream of the channel segment or intersection; T 0_REF is the reference temperature upstream of the channel segment or intersection; T0 is the temperature measured upstream of the channel segment or intersection.

[0142] β(P / P0,n) is the compressibility factor of the flow through the orifice and depends on the ratio between the pressures downstream and upstream of the orifice and on the engine speed (n); in the isentropic case, only the ratio P / Po between the upstream and downstream pressures is known.

[0143] Under the condition of internal exhaust gas recirculation, P0 is the exhaust gas pressure and P is the intake air pressure.

[0144] Alternatively, under exhaust gas conditions, P0 is the intake pressure and P is the exhaust gas pressure.

[0145] According to a more specific embodiment, the above hydraulic permeability crossover point PERM is calculated by the following relationship:

[0146] PERM=A(OVL,n)*fo(H,n)*G(g,n)

[15]

[0147] A(OVL,n) is a first function that depends on the engine speed n and on the duration OVL of the intersection step during which the intake valve 5 and the exhaust valve 7 are simultaneously open.

[0148] fo(H,n) is a second function that depends on the lift H and the engine speed n.

[0149] G(g,n) is a third function representing the center of gravity of the intersection area (i.e. the intersection step between each intake valve 5 and the corresponding exhaust valve 7), depending on the engine speed n and the geometric parameter g. The geometric parameter g represents the angular deviation between the top dead center PMS and the aforementioned center of gravity G.

[0150] Parameters G and g are Figure 6 shown.

[0151] The offset of the intersection point from the top dead center PMS can be expressed by the parameter g, such as:

[0152] g=(EVC–IVO) / 2.

[0153] For illustration purposes only, the following is shown for the calculation used to determine the mass M OVLThe law of mass flow M through a pipe (or through an orifice) section (known in the literature and therefore not described in detail) is:

[0154] M=CD*A*P0 / (R / T0) 1 / 2 *B(P / P0)

[16]

[0155] Where A is the area of ​​the channel section; CD is the discharge coefficient; P is the pressure downstream of the channel section; P0 is the inlet pressure of the channel section; T0 is the inlet temperature of the duct section; R is the gas constant relative to the fluid flowing in the duct section; B is a compressible fluid function known per se (e.g., Figure 7 ).

[0156] Formula

[16] is experimentally applicable to the filling model by integrating between the start time t1 of the intersection step and the end time t2 of the intersection step according to the following relationship:

[0157]

[0158] Among them A IS Represents the isentropic region.

[0159] Substituting the variable dt for dθ / ω (where θ is the motor angle and ω is the motor speed) yields the following relationship:

[0160]

[0161] Finally, assuming that the speed ω of the internal combustion engine 1 is constant during the intersection step, the previous relationship can be simplified as follows:

[0162]

[0163] According to an embodiment, the conditions for the internal exhaust gas recirculation EGRi are such that the exhaust gas pressure P EXH The method further comprises the following steps: calculating the total mass M of the gas inside the cylinder according to the following formula: EGRi , as the estimated mass M of the exhaust gas in the combustion chamber under the condition of internal exhaust gas recirculation EXH_EGR The estimated mass M of the gas flow passing through the intersection step OVL (i.e. the mass of the gas flow from exhaust to intake through intake valve 5 and exhaust valve 7 and then sucked back into cylinder 2 through intake valve 5 during the intake step):

[0164] M EGRi =M OVL +M EXH_EGR

[17]

[0165] According to a particular embodiment, the estimated mass M of the exhaust gas present in the combustion chamber under conditions of internal exhaust gas recirculation is calculated by the relation EXH_EGR :

[0166] M EXH_EGR =(P EXH *V cc ) / (R*T EXH )

[18]

[0167] Where P EXH is the detected exhaust gas flow pressure; T EXH is the detected exhaust gas flow temperature; V cc is the estimated or calculated volume of the combustion chamber of cylinder 2; R is a constant for the fresh air and / or exhaust gas mixture.

[0168] According to another embodiment of the method, the exhaust gas pressure P EXH is less than the intake pressure P, and during the crossover period the fresh air from the intake flows directly to the exhaust, taking away the residual exhaust gas in the combustion chamber, the method comprises the further step of calculating the total air mass M flowing from the intake manifold to the exhaust manifold during the crossover step SCAV , as the estimated mass M of the above gas flow at the intersection step OVL The residual mass M of the exhaust gas inside the combustion chamber of the cylinder 2 and directed directly to the exhaust manifold 6 via the corresponding exhaust valve 7 EXH_SCAV The difference between.

[0169] This calculation can be done using the following formula:

[0170] M SCAV =M OVL -M EXH_SCAV

[19]

[0171] According to a possible example of an embodiment, the above exhaust gas residual mass M EXH_SCAV Calculated by the following formula:

[0172] M EXH_SCAV =[(P EXH *V cc ) / (R*T EXH )]*f SCAV (M OVL ,n)

[20]

[0173] Where P EXH is the detected exhaust gas flow pressure; T EXH is the detected exhaust gas flow temperature; V cc is the estimated or calculated volume of the combustion chamber of cylinder 2; R is a constant for the fresh air and / or exhaust gas mixture.

[0174] f SCAV (M OVL , n) is the multiplication factor, which is the gas flow mass M flowing through the intersection step OVL and the engine speed n.

[0175] According to another possible example of the embodiment, the above-mentioned exhaust gas residual mass M EXH_SCAV Calculated by the following formula:

[0176] M EXH_SCAV =M OVL *f SCAV (M OVL ,n)*g2(g,n)

[21]

[0177] Among them, M OVL is the mass of gas flow through the intersection step; f SCAV (M OVL ,n) is the multiplication factor, which is the gas flow mass (M) flowing through the intersection step OVL ) and the engine speed n; g2(g,n) is a function of the position of the center of gravity G of the intersection step and the engine speed n.

[0178] An embodiment of the method will now be described which explains in more detail how the above-mentioned OFF variable is determined, which represents the mass of gases produced by combustion in the previous working cycle and present in the cylinder 3 (because they did not escape from the cylinder 3 or because they were sucked back into the cylinder 3).

[0179] The filling model is designed to determine a variable OFF which varies as a function of the operating conditions, in particular as a function of the ratio between the pressure in the intake manifold 4 and the pressure in the exhaust manifold 6 .

[0180] If the pressure in the exhaust manifold 6 is higher than the pressure in the intake manifold 4 (“internal EGR” mode), the variable OFF corresponds to the total mass MEGRi of “internal EGR” expressed according to the aforementioned formula

[17] .

[0181] If the pressure in the intake manifold 4 is higher than the pressure in the exhaust manifold 6 ("exhaust gas removal" mode), the OFF variable will be represented by the following formula

[22] (the meaning of the variables included in it has been explained above):

[0182] OFF=(P EXH *V CC ) / (R*T EXH )–M EXH_SCAV [twenty two]

[0183] In fact, in this case, the gases produced by combustion in the previous working cycle and present in the cylinder 2 (since they do not escape) are directed at least partially during the intersection step directly to the exhaust manifold 6 through the corresponding exhaust valve 7. The OFF variable assumes a positive or null value; if the entire gas flow produced by combustion in the previous working cycle and present in the cylinder 3 is directed directly to the exhaust manifold 6 through the exhaust valve 7 during the intersection step, the electronic control unit 10 is configured to saturate the OFF variable to the value zero.

[0184] If the OFF variable takes negative values, for example due to dynamic and cooling effects in the combustion chamber of the cylinder 3 , the electronic control unit 10 may be configured to saturate the OFF variable to negative values.

[0185] Note that the above model has been implemented in a control unit and experimentally verified with satisfactory results, i.e. with an estimation accuracy lower than 3% absolute error compared to the measurement of the air mass at the engine rig.

[0186] In other words, according to an embodiment of the method, the step of determining the gas mass OFF produced by combustion in the previous operating cycle and present in the cylinder 2 first provides for identifying the exhaust gas flow pressure P in the exhaust manifold 6 EXH Whether it is greater than or less than the intake air flow pressure in the intake manifold 4.

[0187] If the pressure P in the exhaust manifold EXH greater than the pressure P in the intake manifold, providing the following steps: determining, based on the filling model, a measured value or an estimated value for each of a second set of reference quantities, the second set of reference quantities including the exhaust gas flow pressure P EXH , the temperature of the exhaust gas flow T EXH , the volume V of the combustion chamber of the cylinder cc and the mass M flowing from the exhaust to the intake through the intake valve 5 and the exhaust valve 7 and then sucked back into the cylinder 2 through the intake valve 5 during the intake step. OVL Then, based on the above second set of reference quantities, the gas mass OFF produced by combustion in the previous working cycle and present in the cylinder 2 is calculated.

[0188] If the pressure P in the exhaust manifold EXH Below the pressure P in the intake manifold, the following steps are provided: based on the filling model, determining a measured value or an estimated value for each of a second set of reference quantities, the second set of reference quantities including the exhaust gas flow pressure P EXH , the temperature of the exhaust gas flow T EXH , the volume V of the combustion chamber of the cylinder cc and the residual mass M of the exhaust gas present in the combustion chamber of the cylinder 2 which is directed via the corresponding exhaust valve 7 directly to the exhaust manifold 6 EXH_SCAV; Then, based on the above-mentioned second set of reference quantities, the gas mass OFF produced by combustion in the previous operating cycle and present in the cylinder 2 is calculated.

[0189] According to an embodiment, if the pressure PEXH in the exhaust manifold is greater than the pressure P in the intake manifold, the mass OFF of gas produced by combustion in the previous operating cycle and present in the cylinder 2 is calculated by the following relationship:

[0190] OFF=M OVL +(P EXH *V cc ) / (R*T EXH )[twenty three]

[0191] where R is a constant for the fresh air and / or exhaust gas mixture.

[0192] According to the embodiment, considering the above formula

[15] , the quantity M OVL Use formula

[14] to calculate.

[0193] According to another embodiment, if the pressure P in the exhaust manifold EXH Below the pressure P in the intake manifold, the gas mass OFF produced by combustion in the previous operating cycle and present in cylinder 2 is calculated using the previous relation

[22] :

[0194] OFF=(P EXH *V cc ) / (R*T EXH )-M EXH_SCAV

[0195] where R is a constant for the fresh air and / or exhaust gas mixture.

[0196] Depending on the options implemented, the quantity M EXH_SCAV Calculate using the above formula

[20] or the above formula

[21] .

[0197] According to another embodiment of the method, an empirical correction factor is taken into account to improve the estimate of the air mass trapped in the cylinder.

[0198] In particular, according to such an embodiment, the air mass m captured in each cylinder 2 is calculated based on multiple multiplication factors (K1, K2), which take into account the angle of the angular displacement VVTi of the intake valve 5, the angle of the angular displacement (VVTe) of the exhaust valve 7 and the speed n of the internal combustion engine 1.

[0199] According to an embodiment, the air mass m captured in each cylinder 2 is calculated based on a first multiplication factor K1 taking into account the intake valve displacement angle VVti and the exhaust valve displacement angle VVte and based on a second multiplication factor K2 taking into account the engine speed n and the exhaust valve displacement angle VVte.

[0200] According to a specific implementation example, the air mass m trapped in each cylinder 2 is calculated by the following relationship

[24] :

[0201] m=[(P*V)–OFF]*K T *K1(VVT i ,VVT e )*K2(VVT e ,n)

[0202] Where K T is determined by the temperature T detected in the intake manifold 4 and the temperature T of the engine coolant H2O The third coefficient of .

[0203] According to the embodiment, referring to the above functions f1 and f2, the coefficient K T Calculated according to the following formula:

[0204] K T =f1(T,P)*f2(T H2O ,P)

[25]

[0205] An embodiment of the method will now be described which can be applied to an external recirculation circuit EGRe comprising exhaust gases with a known flow rate (corresponding to the mass M recirculated by the external circuit for each cylinder per cycle). EGRe ) of an internal combustion engine 1.

[0206] According to this embodiment, the step of calculating the air mass m trapped in each cylinder 2 comprises calculating the air mass m trapped in each cylinder 2 by the following formula:

[0207] m=(P*V-OFF)*f1(T,P)*f2(T H2O ,P)-M EGRe

[26]

[0208] According to an embodiment, the step of calculating the air mass m trapped in each cylinder 2 comprises calculating the air mass m trapped in each cylinder 2 by the following formula

[27] :

[0209] m=[(P*V)–OFF]*K T *K1(VVT i ,VVT e )*K2(VVT e ,n)–MEGRe

[0210] According to an embodiment, if the external EGR mass flow is known and the total number of cylinders is N cyl , the external EGR mass M absorbed by each cylinder per cycle EGRe It can be derived from the following formula:

[0211]

[0212] So we get the formula:

[0213]

[0214] An embodiment of the method will now be described, which is applicable to situations in which the exhaust gas exclusion condition occurs and in which the internal combustion engine 1 further comprises an external recirculation circuit EGRe of exhaust gas with a known flow rate, which corresponds to the mass M recirculated by the external circuit for each cylinder per cycle. EGRe .

[0215] In such an embodiment, the method comprises the further step of calculating the above mass M recirculated by the external circuit per cylinder per cycle EGRe The total mass M sucked by the engine per cylinder per cycle TOT (i.e. the total mass of the gas mixture flowing in the intake manifold 4 of the cylinder 2) EGR Therefore, R EGR =M EGRe / M TOT .

[0216] In addition, the air mass M flowing from the intake manifold to the exhaust manifold during the intersection step is calculated SCAV The steps include calculating the total gas mass M inside the cylinder by the following equation SCAV :

[0217] M SCAV =(M OVL -M EXH_SCAV )*(1–R EGR )

[28]

[0218] An embodiment of the method will now be described which can be applied to situations in which the exhaust gas exclusion condition occurs and in which, moreover, the internal combustion engine 1 comprises an external recirculation circuit EGRe of exhaust gas with a known flow rate, which corresponds to a mass M recirculated by the external circuit for each cylinder per cycle. EGRe .

[0219] In such an embodiment, the method comprises the further step of calculating the above mass M recirculated by the external circuit per cylinder per cycle EGRe The total mass M sucked by the engine per cylinder per cycle TOT (i.e. the total mass of the gas mixture flowing in the intake manifold 4 of the cylinder 2) EGR .

[0220] Furthermore, the step of calculating the gas mass OFF produced by combustion in the previous working cycle and present in cylinder 2 is calculated by the following formula

[29] :

[0221] OFF=(P EXH *Vcc) / (R*T EXH )-[M EXH_SCAV *(1–R EGR )]

[0222] According to an embodiment of the method, the above relationship between the mass trapped in the cylinder 2 and the intake pressure P in the intake manifold 4 is expressed by the following formula

[30] :

[0223] m=[(P*f v (IVC,n)*f h (H,n)*f p (P,n))–OFF]*K T *K1(VVT i ,VVT e )*K2(VVT e ,n)

[0224] According to different possible implementations of the method, the intake pressure P of the intake manifold and / or the lift H and / or the intake valve angular displacement VVTi and / or the exhaust valve angular displacement VVTe and / or the temperature T in the intake manifold 4 and / or the temperature T of the engine coolant H2O and / or the exhaust pressure P in the exhaust manifold 6 EXH and / or the detected temperature T of the exhaust gas flow EXH It is detected by corresponding sensors placed at corresponding positions.

[0225] According to different embodiments of the method, the above coefficients or mappings or functions f v (IVC,n) and / or f h (H,n) and / or f p (P,n) and / or f1(T,P) and / or f2(TH2O,P) and / or f e (TVC,n) and / or g e (OVL,n) and / or h e (OVL,n) and / or fs (TVC,n) and / or g s (OVL,n) and / or h s (OVL,n) and / or β(P / P0,n) and / or A(OVL,n) and / or fo(H,n) and / or G(g,n) and / or f SCAV (M OVL ,n) and / or g2(g,n) and / or K1 and / or K2 and / or K T It is determined by a known theoretical relationship or by a relationship obtained by an experiment or characterization step performed on the engine 1 under operating conditions before use, and the above coefficients or mapping or function is stored in a storage device accessible by the device for controlling the operation of the internal combustion engine 1.

[0226] The aforementioned steps of the calculation or determination steps are performed by one or more processors included in the device for controlling the operation of the internal combustion engine 1 (for example, the aforementioned electronic control unit 10).

[0227] According to any of the above-described embodiments, the estimated value of the air mass trapped in the cylinder 3 can be used in many useful ways, for example in order to obtain a target value of the air-fuel ratio (or heading) of the exhaust gases. In other words, once the air mass m trapped in each cylinder 3 has been determined for each cycle by means of the filling model, the electronic control unit 30 is configured to determine the amount of fuel to be injected into the cylinder 3, which allows obtaining a target value of the air-fuel ratio of the exhaust gases.

[0228] Also advantageously, the above relationship between the air mass m trapped in the cylinder and the intake pressure P (or other quantity) may be expressed as a function of the intake pressure P (or other quantity) to obtain a “target value”.

[0229] In this regard, a method for controlling and implementing the operation of at least one cylinder 2 of an internal combustion engine 1 is described herein and is also included in the present invention (for the sake of simplicity, this method will be referred to as a "command and control model" or "command model" below).

[0230] The method comprises the following steps: determining, based on a calculation model using measured and / or estimated physical quantities, a target mass M of combustion air required for each cylinder 2 to meet the engine torque requirement OBJ ; The relationship between the mass captured in the cylinder 2 and the intake pressure P in the intake manifold 4 is then derived by executing the method for determining the mass m of the air captured in each cylinder 2 according to any embodiment previously described in this specification.

[0231] The method for controlling and implementing the operation of at least one cylinder also provides for calculating a target pressure value P that must be present in the intake manifold 4 based on the above-mentioned relationship between the mass trapped in the cylinder 2 and the intake pressure P, as a function of the measured, estimated or applied value of the intake valve lift H of the intake valve 5 and / or the intake valve displacement angle VVTi and / or the exhaust valve displacement angle VVTe. OBJ In order to obtain the above target mass M in cylinder 2 OBJ Finally, the pressure and flow control valve of the intake manifold 4 is started to obtain the above target pressure P in the intake manifold 4. OBJ and the above target mass M in cylinder 2 OBJ .

[0232] According to the embodiment, the target mass M captured in cylinder 2 OBJ and the target intake pressure P in the intake manifold 4 OBJ The above relationship is expressed by the following formula

[31] :

[0233] M OBJ =[(P OBJ *f v (IVC,n)*f h (H,n)*f p (P,n))–OFF]*K T *K1(VVT i ,VVT e )*K2(VVT e ,n) where OFF is the mass of gas produced by combustion and present in the cylinder during the previous operating cycle; f v (IVC,n),f h (H,n),f p (P,n) is a map whose product represents the actual volume V inside each cylinder 2, where the first map f v (IVC,n) is a function of the intake valve closing delay angle IVC and the engine speed n. The second mapping f h (H,n) is a function of the intake valve lift H and the engine speed n. The third mapping f p (P,n) is a function of the intake pressure P and the engine speed n.

[0234] K1 and K2 are multiplication factors which take into account the angle of the intake valve angular displacement VVTi, the angle of the exhaust valve angular displacement VVTe and the rotational speed n of the internal combustion engine 1 .

[0235] K T is a coefficient that depends on the temperature T detected in the intake manifold 4 and the temperature TH2O of the engine coolant.

[0236] According to the example described above, KT It can be expressed by the following formula:

[0237] K T =f1(T,P)*f2(T H2O ,P).

[0238] As an example, more details are given below regarding the above-described method of controlling and implementing the operation of cylinders of an internal combustion engine.

[0239] According to an embodiment, a calculation chain is also stored in the electronic control unit 10, which, starting from the engine torque requested by the user acting on the accelerator pedal, can provide the combustion air mass M required for each cylinder 2 to meet this engine torque demand. OBJ The calculation chain provides that, after the user's action on the accelerator pedal, the engine torque C required at the drive shaft 11 is determined by means of a map stored in the electronic control unit 10 and knowing the speed n (or rpm) of the internal combustion engine 1 . r , then based on the engine torque C r Determine the total drive torque C required at the drive shaft 11 t , then calculate the required engine torque C for each cylinder 2 t,cyl The calculation chain is also configured to determine for each cylinder 2 the value C of the engine torque obtained above t,cyl The required combustion air mass M OBJ .

[0240] Once the mass M has been calculated OBJ To obtain the engine torque value C t,cyl , the electronic control unit 30 is prepared to use the previously described formula between m and P (for example, the above-mentioned formulas [1] or

[10] or

[24] or

[27] of the filling model) in an inverse manner (explicitly expressed with respect to variables other than m).

[0241] In other words, the mass M of combustion air required for each cylinder 2 OBJ A given value of (in this case corresponding to the mass m of air captured in each cylinder 2 for each cycle, according to one of the above formulas), the target pressure value P inside the intake manifold 4 is calculated from the same formula OBJ For example, starting from formula

[24] , interpret m as M OBJ and interpreting P as P OBJ The following formula is given

[32] :

[0242] P OBJ =[M OBJ / (K T *K1*K2)+OFF] / V

[0243] Therefore, the throttle valve 12 is controlled by the electronic control unit 10 to achieve a target pressure value P inside the intake manifold 4 determined by the formula

[32] OBJ .

[0244] Normally, the throttle valve dynamics are faster than the VVH dynamics, which are faster than or comparable to the VVT ​​dynamics, so the command control principle shown above can work properly.

[0245] If the VVH dynamics are higher than the dynamics of the throttle valve (or intake manifold), or in the absence of a throttle valve, the target H lift can be calculated using the command model given a target air mass.

[0246] As mentioned above, the filling model stored inside the electronic control unit 10 uses measured and / or estimated physical quantities (such as temperature and pressure values). The filling model can also use other measured physical quantities and / or target physical quantities, such as: VVT position (which can be measured for estimation of m, and which is measured or "target" for the control and command model) and / or VVH position (which can be measured for estimation of m, and which is measured or "target" for the control and command model).

[0247] For example, the command and control model described herein was tested on a 1500cc turbine engine with VVH and VVT intake and exhaust, achieving satisfactory accuracy within the performance indicators defined for this type of control (ie, ±3%).

[0248] In all the above cases, starting from the estimated mass per cylinder and per engine cycle, taking into account the number of cylinders and the engine speed n (in particular, starting from the estimated mass per cylinder per engine cycle and multiplying it by the number of cylinders, by the engine speed n and by 1 / 2), the flow of the internal combustion engine 1 can be calculated.

[0249] It can be seen that the objects of the present invention are fully achieved by the above estimation and control methods, and the advantages thereof are obvious from the above discussion.

[0250] In particular, the described method and the associated filling model allow the determination of the air mass m trapped in each cylinder and the total air mass M taken in by the internal combustion engine. TOT and / or exhaust gas mass M SCAV and / or internal EGR mass M EGRI .

[0251] The determination of the above variables is performed by this method efficiently, effectively, i.e. with sufficient accuracy (as mentioned before, based on experiments), effectively, i.e. quickly and without requiring excessive computing power in the electronic control unit 10, and cost-effectively, since it does not require the installation of expensive additional components and / or sensors, such as an air flow meter.

[0252] With regard to the embodiments and methods for determining the mass of air captured in each cylinder of an internal combustion engine and the methods for controlling and implementing the operation of at least one cylinder of an internal combustion engine, as described above, without departing from the scope of the appended claims, those skilled in the art may carry out modifications, adaptations and substitutions of the elements with other functionally equivalent elements to meet possible requirements.

[0253] All sign conventions used in all the above formulas are intended to be consistent with the diagrams shown in the accompanying drawings.

[0254] In all the above formulas, all quantities expressed as functions can be understood as vectors that are mapped and / or stored.

[0255] All the features described above belonging to one possible embodiment can be implemented independently of the other described embodiments. It is further worth noting that the word "comprising" does not exclude other elements or steps, and the article "a" does not exclude a plurality. The figures are not drawn to scale because they give priority to the requirement of appropriately highlighting the various parts to make the description clearer.

Claims

1. A method for determining an air mass m trapped in each cylinder (2) of an internal combustion engine (1) comprising a plurality of cylinders (2), wherein each cylinder (2) is connected to an intake manifold (4), from which the cylinder (2) receives fresh air via at least one respective intake valve (5); and each cylinder (2) is connected to an exhaust manifold (6), into which the cylinder (2) introduces exhaust gases resulting from combustion via at least one respective exhaust valve (7), wherein at least one intake valve (5) is driven so as to change the lift H of the intake valve (5) in a controlled manner, The method comprises the following steps: - determining the value of each quantity of a first set of reference quantities, based on a filling model using measured and / or estimated physical quantities, the first set of reference quantities comprising the intake pressure P measured in the intake manifold (4), the engine speed n, the gas mass OFF generated by combustion in a previous operating cycle and present inside the cylinder (2), estimated according to the lift H and according to the closing delay angle IVC of the intake valve depending on the lift H; - based on the filling model, determining the effective internal volume V of each cylinder (2) according to the engine speed n, the lift H of the intake valve and the closing delay angle IVC of the intake valve and the intake pressure P; - The mass m of air trapped in each cylinder (2) is determined from the first set of reference quantities and the effective internal volume V in each cylinder (2) by the following relationship: m=(P*V)–OFF Therein, the effective internal volume V is the product of the volume expressed in volume units and a dimensional constant, which makes the product P*V dimensionally correspond to the mass.

2. The method according to claim 1, characterized in that Also driving at least one intake valve (5) so as to change the intake valve angular displacement VVTi in a controlled manner, and / or driving at least one exhaust valve (7) so as to change the exhaust valve angular displacement VVTe in a controlled manner; Therein, the step of determining the values ​​of the first set of reference quantities includes determining the closing delay angle IVC of the intake valve based on both the lift H of the intake valve and the intake valve angular displacement VVTi.

3. The method according to claim 1, characterized in that The step of determining the effective internal volume V of each cylinder comprises: - through the first mapping f v (IVC,n), the second mapping f h (H,n), the third mapping f p (P,n) Calculate the effective internal volume V of each cylinder (2), The first mapping f v (IVC,n) is a function of the intake valve closing delay angle IVC and the engine speed n. The second mapping f h (H, n) is a function of the intake valve lift H and the engine speed n, and the third mapping f p (P,n) is a function of the intake pressure P and the engine speed n.

4. The method according to claim 1, characterized in that: The step of determining the effective internal volume V of each cylinder comprises: - through the first mapping f v (IVC,n), the second mapping f h (H,n), the third mapping f p (P,n) Calculate the effective internal volume V of each cylinder (2), The first mapping f v (IVC,n) is a function of the intake valve closing delay angle IVC and the engine speed n. The second mapping f h (H, n) is a function of the intake valve lift H and the engine speed n, and the third mapping f p (P,n) is a function of the intake pressure P and the engine speed n.

5. The method according to claim 3, characterized in that: The effective internal volume V of each cylinder (2) is calculated by the following relationship: V=f v (IVC,n)*f h (H,n)*f p (P,n)。 6. The method according to claim 1, characterized in that The first set of reference quantities also includes a temperature T detected inside the intake manifold (4) and a temperature T of the engine coolant. H2O , And the step of determining the mass m of air trapped in each cylinder (2) comprises calculating the mass m of air trapped in each cylinder (2) from the first set of reference quantities and the effective internal volume V in each cylinder (2) by the following relationship: m=[(P*V)–OFF]*f1(T,P)*f2(T H2O ,P) Where f1(T,P) and f2(T H2O ,P) is a known function belonging to the filling model.

7. The method according to any one of claims 1 to 6, characterized in that The following steps are also included: - The intake valve (5) is driven by means of an intake valve lift converter (50) by changing the lift law of the intake valve in a controlled manner, thereby defining the lift H and the intake valve opening advance angle IVO and the intake valve closing delay angle IVC according to a single degree of freedom (γ).

8. The method according to claim 7, characterized in that The driving steps include: - The intake valve opening advance angle IVO is determined by the following relationship IVO(H)=IVO hmax -Live(H), IVO hmax is the intake valve opening advance angle corresponding to the maximum lift, Δivo(H) is the intake valve opening advance angle change depending on the controlled lift H; - The intake valve closing delay angle IVC is determined by the following relationship IVC(H)=IVC hmax -Δivc(H), IVC hmax is the intake valve closing delay angle corresponding to the maximum lift, and Δivc(H) is the change in the intake valve closing delay angle depending on the controlled lift H.

9. The method according to claim 2, characterized in that: The following steps are also included: - further driving the intake valve (5) by means of an intake valve phase shifter (51) by varying the intake valve angular displacement VVTi in a controlled manner, so that the intake valve opening advance angle IVO and the intake valve closing delay angle IVC depend not only on the lift H but also on the intake valve angular displacement VVTi; - the exhaust valve (7) is driven by means of an exhaust valve phase shifter (52) by varying the exhaust valve angle displacement VVTe in a controlled manner, so that both the exhaust valve opening advance angle EVO and the exhaust valve closing delay angle EVC depend on the exhaust valve angle displacement VVTe.

10. The method according to claim 7, characterized in that The following steps are also included: - further driving the intake valve (5) by means of an intake valve phase shifter (51) by varying the intake valve angular displacement VVTi in a controlled manner, so that the intake valve opening advance angle IVO and the intake valve closing delay angle IVC depend not only on the lift H but also on the intake valve angular displacement VVTi; - the exhaust valve (7) is driven by means of an exhaust valve phase shifter (52) by varying the exhaust valve angle displacement VVTe in a controlled manner, so that both the exhaust valve opening advance angle EVO and the exhaust valve closing delay angle EVC depend on the exhaust valve angle displacement VVTe.

11. The method according to claim 8, characterized in that The driving step comprises: - The intake valve opening advance angle IVO is determined by the following relationship IVO(H)=IVO ref -Live(H)–VVTi IVO ref is a reference value of the opening advance angle of the intake valve without phase shift, VVTi is the intake valve phase shifter (51) relative to the reference value IVO ref The displacement angle of the corresponding reference position; - The intake valve closing delay angle IVC is determined by the following relationship IVC(H)=IVC ref -Δivc(H)+VVTi, IVC ref It is the reference value of the intake valve closing delay angle without phase shift; -The exhaust valve opening advance angle EVO is determined by the following relationship HERE=HERE ref -VVTe, EVO ref is a reference value of the exhaust valve opening advance angle in the absence of phase shift, and VVTe is the exhaust valve phase shifter (52) relative to the reference value EVO ref The displacement angle of the corresponding reference position represented by ; - The exhaust valve closing delay angle EVC is determined by the following relationship EVC=EVC ref +VVTe, EVC ref It is the reference value of the exhaust valve closing delay angle without phase shift.

12. The method according to claim 9, characterized in that The driver includes: - The intake valve opening advance angle IVO is determined by the following relationship IVO(H)=IVO ref -Live(H)–VVTi IVO ref is a reference value of the opening advance angle of the intake valve without phase shift, VVTi is the intake valve phase shifter (51) relative to the reference value IVO ref , and Δivo(H) is the change in intake valve opening advance angle depending on the controlled lift H; - The intake valve closing delay angle IVC is determined by the following relationship IVC(H)=IVC ref -Δivc(H)+VVTi, IVC ref is a reference value of the intake valve closing delay angle in the absence of a phase shift, and Δivc(H) is a change in the intake valve closing delay angle depending on the controlled lift H; -The exhaust valve opening advance angle EVO is determined by the following relationship HERE=HERE ref -VVTe, EVO ref is a reference value of the exhaust valve opening advance angle in the absence of phase shift, and VVTe is the exhaust valve phase shifter (52) relative to the reference value EVO ref The displacement angle of the corresponding reference position represented by ; - The exhaust valve closing delay angle EVC is determined by the following relationship EVC=EVC ref +VVTe, EVC ref It is the reference value of the exhaust valve closing delay angle without phase shift.

13. The method according to any one of claims 1 to 6, characterized in that include: If the internal combustion engine (1) is operated with internal exhaust gas recirculation EGRi, a further step is: -Based on the fourth mapping f e (TVC,n), the fifth mapping g e (OVL,n) and the sixth mapping h e (H, n) Calculate the combustion chamber volume Vcc of cylinder (2), the fourth mapping f e (TVC,n) is a function of the first parameter TVC and the engine speed n. The fifth mapping g e (OVL,n) is a function of the second parameter OVL and the engine speed n, and the sixth map h e (H,n) is a function of lift H and engine speed n, wherein the first parameter TVC is alternatively equal to the closing delay angle EVC of the exhaust valve (7) or to the maximum value between zero and the minimum value between the closing delay angle EVC of the exhaust valve (7) and the opening advance angle IVO of the intake valve (5) multiplied by -1, And wherein the second parameter OVL represents the duration of the intersection step between the intake and exhaust curves and is defined as the sum of the exhaust valve closing delay angle EVC and the intake valve opening advance angle IVO.

14. The method according to claim 13, characterized in that The combustion chamber volume V cc Calculated by the following formula: V cc =f e (TVC,n)*g e (OVL,n)*h e (H,n) where f e , g e ,h e is a known function belonging to the filling model.

15. The method according to any one of claims 1 to 6, characterized in that If the internal combustion engine (1) is configured to operate under exhaust gas removal conditions in which the intake pressure is greater than the exhaust pressure, thereby causing the intake of fresh air, which takes away the residual exhaust gas in the combustion chamber, the method further comprises the following steps: -Based on the fourth mapping f s (TVC,n), the fifth mapping g s (OVL,n) and the sixth mapping h s (H,n) Calculate the combustion chamber volume V of cylinder (2) cc , the fourth mapping f s (TVC,n) is a function of the first parameter TVC and the engine speed n. The fifth mapping g s (OVL,n) is a function of the second parameter OVL and the engine speed n, and the sixth map h s (H,n) is a function of lift H and engine speed n, wherein the first parameter TVC is alternatively equal to the closing delay angle EVC of the exhaust valve (7) or to the maximum value between zero and the minimum value between the closing delay angle EVC of the exhaust valve (7) and the opening advance angle IVO of the intake valve (5) multiplied by -1, And wherein the second parameter OVL represents the duration of the intersection step between the intake and exhaust curves and is defined as the sum of the exhaust valve closing delay angle EVC and the intake valve opening advance angle IVO.

16. The method according to claim 15, characterized in that The combustion chamber volume V cc Calculated by the following formula: V cc =f s (TVC,n)*g s (OVL,n)*h s (H,n) where f s , g s ,h s is a known function belonging to the filling model.

17. The method according to any one of claims 1 to 6, characterized in that The further step of calculating the estimated mass M of the gas flow passing through the intersection of the intake valve (5) and the exhaust valve (7) in the case of internal exhaust gas recirculation EGRi or exhaust gas removal SCAV based on the following relationship OVL : M OVL =PERM*β(P / P0,n)*P0 / P 0_REF *(T 0_REF / T0) 1 / 2 / n Where PERM is the hydraulic permeability at the intersection point; n is the engine speed; P 0_REF is the reference pressure upstream of the channel segment or intersection; T 0_REF is the reference temperature upstream of the channel segment or intersection; T0 is the temperature measured upstream of the channel segment or intersection; β(P / P0,n) is the compressibility factor of the flow through the orifice, which depends on the ratio between the pressures downstream and upstream of the orifice and on the engine speed n; And wherein, under the condition of internal recirculation of exhaust gas, P0 is the exhaust pressure, P is the intake pressure, Alternatively, under exhaust gas conditions, P0 is the intake pressure and P is the exhaust pressure.

18. The method according to claim 17, characterized in that The hydraulic permeability PERM of the intersection point is calculated by the following relationship: PERM=A(OVL,n)*fo(H,n)*G(g,n) wherein A(OVL,n) is a first function that depends on the engine speed n and on the duration of the intersection step OVL during which the intake valve (5) and the exhaust valve (7) are simultaneously open; fo(H,n) is the second function, which depends on the lift H and the engine speed n; G(g,n) is a third function representing the centre of gravity of the intersection zone, depending on the engine speed n and a geometric parameter g representing the angular deviation between top dead centre and the centre of gravity G of the intersection step.

19. The method according to claim 17, characterized in that Under the condition of internal exhaust gas recirculation EGRi, the exhaust gas pressure P EXH Greater than the intake pressure, where the exhaust pressure P EXH is the detected or estimated air flow pressure in the exhaust manifold (6), the method further comprising the following steps: - Calculate the total mass M of the gas in the cylinder according to the following formula: EGRi , as the estimated mass M of the exhaust gas in the combustion chamber under the condition of internal exhaust gas recirculation EXH_EGR The estimated mass M of the gas flow passing through the intersection step OVL The sum of which is the estimated mass M OVL is the mass of gas flow from exhaust to intake through intake valve (5) and exhaust valve (7) and then sucked back into cylinder (2) through intake valve (5) during the intake step: M EGRi =M OVL +M EXH_EGR 。 20. The method according to claim 18, characterized in that Under the condition of internal exhaust gas recirculation EGRi, the exhaust gas pressure P EXH is greater than the intake pressure, the method further comprising the following steps: - Calculate the total mass M of the gas in the cylinder according to the following formula: EGRi , as the estimated mass M of the exhaust gas in the combustion chamber under the condition of internal exhaust gas recirculation EXH_EGR The estimated mass M of the gas flow passing through the intersection step OVL The sum of which is the estimated mass M OVL is the mass of the gas flow from exhaust to intake through the intake valve (5) and the exhaust valve (7) and then sucked back into the cylinder (2) through the intake valve (5) during the intake step: M EGRi =M OVL +M EXH_EGR 。 21. The method according to claim 19, characterized in that The estimated mass M of the exhaust gas in the combustion chamber under exhaust gas internal recirculation conditions is calculated by the following relationship: EXH_EGR : M EXH_EGR =(P EXH *V cc ) / (R*T EXH ) The exhaust pressure P EXH is the detected air flow pressure in the exhaust manifold (6); T EXH is the airflow temperature detected in the exhaust; V cc is the estimated or calculated volume of the combustion chamber of cylinder (2); R is a constant for the fresh air and / or exhaust gas mixture.

22. The method according to claim 17, characterized in that Under the condition of eliminating the exhaust gas SCAV, the exhaust pressure P EXH The pressure of the intake air is less than that of the intake air, and during the intersection, fresh air from the intake air flows directly to the exhaust air, taking away the residual exhaust gas in the combustion chamber, and the method further includes the following steps: - Calculate the total air mass M flowing from the intake manifold to the exhaust manifold during the intersection step according to the following formula: SCAV , as the estimated mass M of the gas flow at the intersection step OVL The residual mass M of the exhaust gas inside the combustion chamber of the cylinder (2) and directly led to the exhaust manifold (6) via the corresponding exhaust valve (7) EXH_SCAV The difference between: M SCAV =M OVL -M EXH_SCAV 。 23. The method according to claim 18, characterized in that Under the condition of eliminating the exhaust gas SCAV, the exhaust pressure P EXH The pressure of the intake air is less than that of the intake air, and during the intersection, fresh air from the intake air flows directly to the exhaust air, taking away the residual exhaust gas in the combustion chamber, and the method further includes the following steps: - Calculate the total air mass M flowing from the intake manifold to the exhaust manifold during the intersection step according to the following formula: SCAV , as the estimated mass M of the gas flow at the intersection step OVL The residual mass M of the exhaust gas inside the combustion chamber of the cylinder (2) and directly led to the exhaust manifold (6) via the corresponding exhaust valve (7) EXH_SCAV The difference between: M SCAV =M OVL -M EXH_SCAV 。 24. The method according to claim 22, characterized in that The exhaust gas residual mass M EXH_SCAV Calculated by the following relationship: M EXH_SCAV =[(P EXH *V cc ) / (R*T EXH )]*f SCAV (M OVL ,n) The exhaust pressure P EXH is the detected air flow pressure in the exhaust manifold (6); T EXH is the airflow temperature detected in the exhaust; V cc is the estimated or calculated volume of the combustion chamber of cylinder (2); R is a constant for the fresh air and / or exhaust gas mixture; f SCAV (M OVL , n) is the multiplication factor, which is the estimated mass M of the gas flow flowing through the intersecting step OVL and engine speed n.

25. The method according to claim 22, characterized in that The exhaust gas residual mass M EXH_SCAV Calculated by the following relationship: M EXH_SCAV =M OVL *f SCAV (M OVL ,n)*g2(g,n) Among them, M OVL is the mass of gas flow through the intersection step; f SCAV (M OVL , n) is the multiplication factor, which is the estimated mass M of the gas flow flowing through the intersection step OVL and the function of engine speed n; g2(g,n) is a function of the position of the center of gravity G of the intersection step and the engine speed n.

26. The method according to any one of claims 1 to 6, characterized in that The step of determining the gas mass OFF produced by combustion in the previous operating cycle and present inside the cylinder (2) comprises the following steps: - Identify the exhaust pressure P EXH whether it is greater than or less than the intake air flow pressure P in the intake manifold (4); If the exhaust pressure P EXH Greater than the intake manifold pressure P: - based on said filling model, determining a measured or estimated value for each of a second set of reference quantities, said second set of reference quantities comprising the exhaust gas pressure P EXH , the air flow temperature in the exhaust gas T EXH , cylinder combustion chamber volume V cc and the estimated mass M that flows from the exhaust to the intake through the intake valve (5) and the exhaust valve (7) and is then sucked back into the cylinder (2) through the intake valve (5) during the intake step OVL - calculating, from said second set of reference quantities, the gas mass OFF produced by combustion during the preceding operating cycle and present inside the cylinder (2); If the exhaust pressure P EXH Less than the intake manifold pressure P: - based on said filling model, determining a measured or estimated value for each of a second set of reference quantities, said second set of reference quantities comprising the exhaust gas pressure P EXH , the air flow temperature in the exhaust gas T EXH , cylinder combustion chamber volume V cc and the residual mass M of the exhaust gas present in the combustion chamber of the cylinder (2) and directed via the corresponding exhaust valve (7) to the exhaust manifold (6) EXH_SCAV ; - Based on the second set of reference quantities, the gas mass OFF produced by combustion during the previous operating cycle and present inside the cylinder (2) is calculated.

27. The method according to claim 26, characterized in that If the exhaust pressure P EXH Greater than the pressure in the intake manifold, the mass OFF of the gas produced by combustion in the previous operating cycle and present inside the cylinder (2) is calculated by the following relationship: OFF=M OVL +(P EXH *V cc ) / (R*T EXH ) where R is a constant for the fresh air and / or exhaust gas mixture, M OVL is the estimated mass of the gas flow flowing through the intersection step of the intake valve (5) and the exhaust valve (7).

28. The method according to claim 27, characterized in that In the case of internal exhaust gas recirculation EGRi or exhaust gas removal SCAV, the estimated mass M of the gas flow flowing through the intersection step of the intake valve (5) and the exhaust valve (7) is calculated based on the following relationship OVL : M OVL =PERM*β(P / P0,n)*P0 / P 0_REF *(T 0_REF / T0) 1 / 2 / n Where PERM is the hydraulic permeability at the intersection point; n is the engine speed; P 0_REF is the reference pressure upstream of the channel segment or intersection; T 0_REF is the reference temperature upstream of the channel segment or intersection; T0 is the temperature measured upstream of the channel segment or intersection; β(P / P0,n) is the compressibility factor of the flow through the orifice, which depends on the ratio between the pressures downstream and upstream of the orifice and on the engine speed n; And wherein, under the condition of internal recirculation of exhaust gas, P0 is the exhaust pressure, P is the intake pressure, Alternatively, under exhaust gas conditions, P0 is the intake pressure and P is the exhaust pressure.

29. The method according to claim 26, characterized in that If the exhaust pressure P EXH is less than the pressure P in the intake manifold, the gas mass OFF produced by combustion in the previous operating cycle and present inside the cylinder (2) is calculated by the following relationship: OFF=(P EXH *V cc ) / (R*T EXH )-M EXH_SCAV where R is a constant for the fresh air and / or exhaust gas mixture.

30. The method of claim 29, wherein: The exhaust gas residual mass M EXH_SCAV Calculated by the following relationship: M EXH_SCAV =[(P EXH *V cc ) / (R*T EXH )]*f SCAV (M OVL ,n) The exhaust pressure P EXH is the detected exhaust pressure in the exhaust manifold (6); T EXH is the airflow temperature detected in the exhaust; V cc is the estimated or calculated volume of the combustion chamber of cylinder (2); R is a constant for the fresh air and / or exhaust gas mixture; f SCAV (M OVL , n) is the multiplication factor, which is the estimated mass M of the gas flow flowing through the intersecting step OVL and engine speed n.

31. The method according to any one of claims 3 to 5, characterized in that The air mass m trapped in each cylinder (2) is calculated according to a plurality of multiplication factors which take into account the angle of the intake valve angular displacement VVTi, the angle of the exhaust valve angular displacement VVTe and the rotational speed n of the internal combustion engine (1).

32. The method according to claim 31, characterized in that The air mass m captured in each cylinder (2) is calculated as follows: - a first multiplication factor K1, which takes into account the angle of the intake valve angular displacement VVTi and the angle of the exhaust valve angular displacement VVTe, and a second multiplication factor K2 which takes into account the rotational speed n of the internal combustion engine (1) and the angle of the exhaust valve angular displacement VVTe.

33. The method according to claim 32, characterized in that The air mass m trapped in each cylinder (2) is calculated by the following relationship: m=[(P*V)–OFF]*K T *K1(VVT i ,VVT e )*K2(VVT e ,n) Where K T is determined by the temperature T detected in the intake manifold (4) and the temperature T of the engine coolant H2O The third coefficient of .

34. The method according to claim 6, characterized in that The internal combustion engine (1) comprises an external recirculation circuit EGRe of exhaust gas with a known flow rate, corresponding to a mass M recirculated by the external circuit for each cylinder per cycle EGRe , The step of calculating the air mass m captured in each cylinder (2) comprises calculating the air mass m captured in each cylinder (2) by the following formula: m=(P*V-OFF)*f1(T,P)*f2(T H2O ,P)-M EGRe 。 35. The method according to claim 33, characterized in that The internal combustion engine (1) comprises an external recirculation circuit EGRe of exhaust gas with a known flow rate, corresponding to a mass M recirculated by the external circuit for each cylinder per cycle EGRe , The step of calculating the air mass m trapped in each cylinder (2) comprises calculating the air mass m trapped in each cylinder (2) by the following formula: m=[(P*V)–OFF]*K T *K1(VVT i ,VVT e )*K2(VVT e ,n)-M EGRe in, K1 is the first multiplication factor, which takes into account the angle of the intake valve angular displacement VVTi and the angle of the exhaust valve angular displacement VVTe, K2 is a second multiplication factor, which takes into account the rotation speed n of the internal combustion engine (1) and the angle of the exhaust valve angular displacement VVTe; M EGRe is the mass recirculated by the external circuit per cylinder per cycle.

36. The method according to claim 22, characterized in that The exhaust gas exclusion condition occurs and the internal combustion engine (1) comprises an external recirculation circuit EGRe of exhaust gas with a known flow rate, corresponding to the mass M recirculated by the external circuit for each cylinder per cycle EGRe , The method further comprises the step of calculating the mass M recirculated by the external circuit per cylinder in each cycle. EGRe The total mass M sucked by the engine per cylinder per cycle TOT The ratio R EGR , total mass M TOT is the total mass of the gas mixture flowing in the intake manifold (4) of the cylinder (2); and wherein the air mass M flowing from the intake manifold to the exhaust manifold during the intersection step SCAV It is calculated by the following relationship: M SCAV =(M OVL -M EXH_SCAV )*(1–R EGR )。 37. The method according to claim 23, characterized in that The exhaust gas exclusion condition occurs and the internal combustion engine (1) comprises an external recirculation circuit EGRe of exhaust gas with a known flow rate, corresponding to the mass M recirculated by the external circuit for each cylinder per cycle EGRe , The method further comprises the step of calculating the mass M recirculated by the external circuit per cylinder in each cycle. EGRe The total mass M sucked by the engine per cylinder per cycle TOT The ratio R EGR , total mass M TOT is the total mass of the gas mixture flowing in the intake manifold (4) of the cylinder (2); and wherein the air mass M flowing from the intake manifold to the exhaust manifold during the intersection step SCAV It is calculated by the following relationship: M SCAV =(M OVL -M EXH_SCAV )*(1–R EGR )。 38. The method according to claim 24, characterized in that The exhaust gas exclusion condition occurs and the internal combustion engine (1) comprises an external recirculation circuit EGRe of exhaust gas with a known flow rate, corresponding to the mass M recirculated by the external circuit for each cylinder per cycle EGRe , The method further comprises the step of calculating the mass M recirculated by the external circuit per cylinder in each cycle. EGRe The total mass M sucked by the engine per cylinder per cycle TOT The ratio R EGR， Total mass M TOT is the total mass of the gas mixture flowing in the intake manifold (4) of the cylinder (2); and wherein the air mass M flowing from the intake manifold to the exhaust manifold during the intersection step SCAV It is calculated by the following relationship: M SCAV =(M OVL -M EXH_SCAV )*(1–R EGR )。 39. The method according to claim 29, characterized in that The exhaust gas exclusion condition occurs, and wherein the internal combustion engine (1) comprises an external recirculation circuit EGRe of exhaust gas with a known flow rate, which corresponds to a mass M recirculated by the external circuit for each cylinder per cycle EGRe , The method further comprises the step of calculating the mass M recirculated by the external circuit per cylinder in each cycle. EGRe The total mass M sucked by the engine per cylinder per cycle TOT The ratio R EGR , total mass M TOT is the total mass of the gas mixture flowing in the intake manifold (4) of the cylinder (2); And wherein the step of calculating the gas mass OFF produced by combustion in the previous operating cycle and present inside the cylinder (2) is calculated by the following relationship: OFF=(P EXH *Vcc) / (R*T EXH )-[M EXH_SCAV *(1–R EGR )]。 40. The method according to claim 30, characterized in that The exhaust gas exclusion condition occurs, and wherein the internal combustion engine (1) comprises an external recirculation circuit EGRe of exhaust gas with a known flow rate, which corresponds to a mass M recirculated by the external circuit for each cylinder per cycle EGRe , The method further comprises the step of calculating the mass M recirculated by the external circuit per cylinder in each cycle. EGRe The total mass M sucked by the engine per cylinder per cycle TOT The ratio R EGR , where the total mass M TOT is the total mass of the gas mixture flowing in the intake manifold (4) of the cylinder (2); And wherein the step of calculating the gas mass OFF produced by combustion in the previous operating cycle and present inside the cylinder (2) is calculated by the following relationship: OFF=(P EXH *Vcc) / (R*T EXH )-[M EXH_SCAV *(1–R EGR )]。 41. The method according to claim 35, characterized in that The target mass M captured in cylinder (2) is expressed by OBJ and the target intake pressure P in the intake manifold (4) OBJ The relationship between: M OBJ =[(P OBJ *f v (IVC,n)*f h (H,n)*f p (P,n))–OFF]*K T *K1(VVT i ,VVT e )*K2(VVT e ,n), The effective internal volume V of each cylinder (2) is calculated by the following relationship: V=f v (IVC,n)*f h (H,n)*f p (P,n)。 42. The method according to claim 6, characterized in that The intake pressure P and / or the lift H of the intake valve and / or the intake valve angular displacement VVTi and / or the exhaust valve angular displacement VVTe and / or the temperature T in the intake manifold (4) and / or the temperature T of the engine coolant H2O and / or an exhaust pressure P of the exhaust manifold (6) for detecting or estimating the air flow pressure EXH and / or the detected temperature T of the exhaust gas flow EXH It is detected by corresponding sensors placed at corresponding positions.

43. The method according to claim 31, characterized in that: - the coefficients or mapping or function f v (IVC,n) and / or f h (H,n) and / or f p (P,n) and / or f0(T,P) and / or f2(T H2O ,P) and / or fe(TVC,n) and / or g e (OVL,n) and / or h e (OVL,n) and / or f s (TVC,n) and / or g s (OVL,n) and / or h s (OVL,n) and / or β(P / P0,n) and / or A(OVL,n) and / or fo(H,n) and / or G(g,n) and / or f SCAV (M OVL ,n) and / or g2(g,n) and / or K1 and / or K2 and / or K T is determined under operating conditions using previously known theoretical relationships or relationships obtained by experimental or characterization steps performed on the internal combustion engine (1), and the above coefficients or mapping or function is stored in a storage device accessible by the device for controlling the operation of the internal combustion engine (1), And wherein the calculating or determining step is performed by one or more processors included in the device (10) for controlling the operation of the internal combustion engine (1).

44. A method for controlling and implementing the operation of at least one cylinder (2) of an internal combustion engine (1), comprising the following steps: - Based on a calculation model using measured and / or estimated physical quantities, determining the target mass M of combustion air required for each cylinder (2) to meet the engine torque requirement OBJ ; - obtaining a relationship between the mass trapped in the cylinder (2) and the intake pressure in the intake manifold (4) by carrying out a method for determining the air mass m trapped in each cylinder (2) according to any one of claims 1 to 43; - Based on the relationship between the mass trapped in the cylinder (2) and the intake pressure, the target pressure P present in the intake manifold (4) is calculated as a function of the measured, estimated or set value of the lift H of the intake valve (5) and / or the angle of the intake valve angular displacement VVTi and / or the angle of the exhaust valve angular displacement VVTe OBJ In order to obtain the target mass M in the cylinder (2) OBJ ; - actuating the pressure and flow control valve of the intake manifold (4) so ​​as to obtain said target pressure P in the intake manifold (4) OBJ and the target mass M in cylinder (2) OBJ .

45. The method according to claim 44, characterized in that The target mass M captured in the cylinder (2) OBJ and the target pressure P in the intake manifold (4) OBJ The relationship between is expressed by the following formula: M OBJ =[(P OBJ *f v (IVC,n)*f h (H,n)*f p (P,n))–OFF] *K T *K1(VVT i ,VVT e )*K2(VVT e ,n) where OFF is the mass of gas produced by combustion during the preceding operating cycle and present inside the cylinder (2); f v (IVC,n),f h (H,n),f p (P,n) is a map whose product represents the actual volume V inside each cylinder (2), where the first map f v (IVC,n) is a function of the intake valve closing delay angle IVC and the engine speed n. The second mapping f h (H,n) is a function of the intake valve lift H and the engine speed n. The third mapping f p (P,n) is a function of intake pressure and engine speed n; K1 and K2 are multiplication coefficients which take into account the angle of the intake valve angular displacement VVTi, the angle of the exhaust valve angular displacement VVTe and the speed n of the internal combustion engine (1); K T is determined by the temperature T detected in the intake manifold (4) and the temperature T of the engine coolant H2O The coefficient of .

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