WO2014191665A1

WO2014191665A1 - Method for estimating the pollutant emissions of an internal combustion engine and related method for controlling the engine

Info

Publication number: WO2014191665A1
Application number: PCT/FR2014/051212
Authority: WO
Inventors: Vincent Talon; Jamil EL-HADEF; Nicolas BORDET
Original assignee: Renault S.A.S.
Priority date: 2013-05-31
Filing date: 2014-05-23
Publication date: 2014-12-04
Also published as: EP3004608A1; FR3006372A1; FR3006372B1; EP3004608B1

Abstract

The invention relates to a method for managing an internal combustion engine (1), which involves estimating at least one value (Pollut) of emission of a pollutant species by means of engine parameters other than the gas pressure in the cylinders (6) of the engine (1), at least one first value of pollutant emissions being calculated as the product of a first affine function of fuel consumption (Q_carb), a second affine function of the spark advance function (φ) of the engine, a third affine function of the temperature (T) of the coolant of the engine, and a negative exponential term of a power of the richness (R) of the comburent mixture in the cylinders (6) of the engine.

Description

Method for estimating pollutant emissions from an internal combustion engine and associated engine control method

The object of the invention is to control the polluting emissions of an internal combustion engine. The level of pollutant emissions of the engine depends in particular on the combustion conditions of the combustion mixture in the engine cylinders. It therefore depends on the composition of the mixture, but also on the temperature and pressure conditions at which the combustion takes place in the cylinders.

One of the known variables for evaluating the production level of various polluting emissions is the pressure developed in the cylinders at the moment of combustion. The knowledge of this pressure, however, requires the use of specific sensors, which leads to an additional cost of the engine. The sensor can also easily be damaged due to the pressures and temperatures used.

The aim of the invention is to propose methods for evaluating the emissions of one or more polluting species, which use sensors and estimators other than pressure sensors in the cylinders, the sensors used being generally already present on the engine for other engine control purposes, for example to optimize the fuel consumption of the engine.

The object of the invention is also to propose inexpensive estimation methods in computing capacities, and methods which require, in order to be calibrated, a reduced number of bench tests.

The aim of the invention is also to allow a reduction of the pollutant emissions of the engine, by introducing a consideration of the estimated values of pollutant emissions, when driving the engine in order to obtain the desired engine torque by the driver of the vehicle. . To this end, the invention proposes an internal combustion engine, the engine comprising a pollutant emission estimating device. Preferably, the engine has no pressure sensor in any cylinder of the engine, or at least the pollutant estimator does not use pressure values obtained by sensor measurement in one or more cylinders of the engine. The estimation device is configured to calculate a first pollutant emission value by taking into account the rotational speed of the engine, a measured temperature of coolant circulating in the engine, a fuel consumption of the engine, an estimated indicative value. the richness of the gases entering the engine cylinders, and a level of advance ignition engine. The richness of the gases can be calculated in different ways according to the embodiments. According to a first embodiment, the richness can be calculated from a flow of fresh air entering the engine, and the fuel consumption of the engine. The fresh air flow can itself be measured by a flow meter, or can be estimated by means of a flow map which is a function, in particular, of the engine rotation speed and a gas pressure measured in the engine. intake manifold. The value extracted from the flow map can be multip tied by a measured pressure in the engine intake manifold, and can be divided by a temperature measured in the engine intake manifold. The cartography can also take into account instructions for controlling intake valves and gas exhaust from the engine cylinders.

According to another embodiment, the richness of the gases entering the cylinders of the engine can be estimated by taking into account the mass actually trapped in the combustion chamber of the cylinders. It can then typically be calculated by reading a first value in a fill map, and a second value in a trapping map, and multiplying these two values by a constant coefficient and by a measured gas pressure in the coilector. engine intake and dividing the result by a measured gas temperature in the engine intake manifold. In the case where the engine is equipped with a phase shift system of the openings of the intake and exhaust valves of the cylinders, the filling mapping and trapping mapping can take into account, in addition to the engine speed and the pressure of the engines. gas in the intake manifold, instructions for controlling intake valves and exhaust gases from the engine cylinders.

According to a first embodiment, the estimation device is configured to calculate a first emission value po lluantes as the product of a first function affine of fuel consumption, a second function affine the advance to ignition, a third function refines the coolant temperature, and a negative exponential term a power of the gas richness entering the cylinders. Advantageously, the first emission value is used to estimate the emissions of nitrogen oxides from the engine. By negative exponential term we mean a term where the value under the exponential is of negative sign.

Preferably, the negative term under the exponential function is proportional to a power function of a difference between the richness of gas entering the engine and a threshold richness.

According to a preferred embodiment, the power function is a power equal to two.

According to a second embodiment which can be combined with the above, the estimation device is configured to calculate a second emission value, as a product of an affine function of the coolant temperature by the fuel consumption. of the engine, and by a third function refines the richness of the gases entering the cylinders of the engine. Advantageously, the second emission value is used to estimate the carbon monoxide emissions of the engine.

Below a threshold richness, the estimation device can be configured to replace the third affine function of the richness of the gases entering the cylinders of the engine by a constant value. According to a third embodiment which can be combined with the two preceding embodiments, the estimating device is furthermore connected to a pressure sensor in an engine intake manifold and to a gas temperature sensor in the commutator. intake of the engine, and a means for estimating the rotational speed of the engine and a means for estimating the air flow entering the engine. The pollutant estimating device is then configured to calculate a third pollutant value, such as a product of an affine function of the ignition timing, by an affine function of the coolant temperature. , multip linked by a first polynomial of the second degree according to the inverse of the rotation speed of the motor, by a second polynomial of the second degree depending on the richness, and by a third polynomial of the second degree depending on a reduced variable. The reduced variable is proportional to the air flow entering the engine and the temperature of the gases in the intake manifold, and inversely proportional to the gas pressure in the intake manifold of the engine. Advantageously, the third emission value is used to estimate emissions of incompletely burned hydrocarbons.

According to an advantageous embodiment, the motor may further comprise a regulator configured to take into account a signal of an accelerator pedal. The controller is configured to develop from this signal a position setpoint of an actuator of the engine, by weighting the position setpoint with a value mapped according to at least one polluting emission value calculated by the estimator of the engine. polluting emissions.

According to an advantageous embodiment, the engine comprises a first mapping giving a first multiplier coefficient according to one or more pollutant values calculated by the pollutant estimator, and comprises a second mapping making it possible to read a second multiplying coefficient according to the pedal signal and the motor rotation speed. The regulator is then configured to applying the product of the first and second coefficients to a setpoint variance variable, the setpoint difference variable translating a difference between a setpoint value calculated as a function of the pedal signal, and a measured variable or a derived variable measurements- on the engine.

The invention also proposes a hybrid vehicle comprising an electric machine and comprising a motor as described above. The vehicle may comprise an energy management module configured to deliver an electric torque setpoint to be supplied by the electric machine and to deliver a desired value of thermal torque to be supplied by the internal combustion engine. The vehicle may furthermore comprise a moderator module configured to weight the desired value of thermal torque as a function of an estimated value of pollutant emissions, and to deliver a setpoint thermal torque for developing a position setpoint of an actuator of the internal combustion engine. According to a preferred embodiment, the moderator module also returns the target thermal torque to the energy management module, which accordingly adapts the electrical torque setpoint.

The invention also proposes an engine equipped with a polluting species trap (s) and an estimation device configured to calculate an instantaneous value of polluting emissions corresponding to the species to be trapped. The engine may include a trap monitor configured to determine the amount of pollutant species accumulated in the trap by integrating a value estimated by the estimator. The pollutant species trap may for example be a nitrogen oxide trap. According to a preferred embodiment, the trap monitor is configured to trigger a purge of the trap when the amount of polluting species in the trap reaches or exceeds a threshold, which may be a function of the driving conditions of the vehicle. Purge means elimination by oxidation or reduction of polluting species. In the case of the nitrogen oxide trap, the purge can be done by modifying the operating parameters of the engine so as to heat the trap and to send reducing chemical species. These purge methods are known, for example to reduce nitrogen oxides to nitrogen.

The invention also applies to a method for managing an internal combustion engine, in which at least one emission value of a polluting species is estimated using engine parameters other than the gas pressure in the engine. the engine cylinders, at least one polluting emission value being calculated as the product of a first function affine of the fuel consumption, a second function affine of the ignition advance, a third function refining of the coolant temperature, and a negative exponential term of a power of the richness of the combustion mixture in the engine cylinders.

Other objects, features and advantages of the invention will become apparent on reading the following description, given solely by way of nonlimiting example, and with reference to the appended drawings in which:

FIG. 1 is a schematic representation of an internal combustion engine equipped with a pollutant emission estimator according to the invention, FIG. 2 is a schematic representation of an internal combustion engine equipped with a trap. IEC 60050 - International Electrotechnical Vocabulary - Details for IEV number 845-02-08 Superposition of a nitric oxide system and a pollutant emission estimator according to the invention FIG. 3 is a diagrammatic representation of a hybrid thermal - electric motorization system, provided with a device for estimating pollutant emissions. pollutant emissions according to the invention.

As illustrated in FIG. 1, an internal combustion engine 1, for example a gasoline engine, comprises combustion cylinders 6, of which there are four, and comprises an air supply circuit 30 extending from one engine to the other. fresh air inlet 3 to exhaust outlet 3 1. The air enters through the fresh air inlet 3, passes through an air filter 4, which may or may not have a flow meter, then passes through a compressor 5a of a turbocharger 5, for arrive in an intake manifold 32 from which it can be admitted into the cylinders 6 of the engine 1.

The gas circuit 30 continues downstream of the cylinders 6 by an exhaust manifold 39 which receives the flue gases from the cylinders 6. The flue gases then pass through a turbine 5b of the turbocharger 5, and then eventually pass through a deposition system. 33, to be returned to the atmosphere via the exhaust outlet 3 1.

The arrival of gasoline to each cylinder 6 from the fuel tank 19 of the vehicle is controlled by an engine control unit 8 which determines the quantity of fuel Q _ca rb admitted in each cylinder at each "stroke" engine, that is to say for each engine cycle of the cylinder. The engine control unit 8 also determines an ignition advance φ which is the angle that remains to be traveled at the crankshaft before reaching the top dead center, at the moment when a spark is triggered in the corresponding cylinder.

The quantity of fuel Q _car b sent to each cylinder at each "stroke" or engine cycle, as well as the ignition advance φ, are sent to a pollutant estimator 10. The pollutant estimator 10 is an electronic control unit further receiving a motor "water temperature" value T, measured by a sensor 34 measuring the temperature of the coolant passing through the engine. The estimator 10 also receives a value of engine speed N, which can for example be expressed in revolutions per minute, and which is measured by a tachometer 35, placed for example facing a solid toothed wheel of the crankshaft of the engine 1 .

The pollutant estimator 10 also receives a richness value R of the oxidant mixture entering the engine cylinders. This wealth value can be delivered by a wealth estimator 2. The estimator 2 oxidizer mixture richness, may be used in particular Q fuel flow _because b entering the engine cylinders at each stroke, and the air flow _Q i _r entering the circuit gas supply 30. The estimator 2 may, according to other embodiments, perform the estimation of wealth from other parameters, as detailed below.

The air flow rate Q _a i _r can be measured by a flowmeter, for example placed at the level of the air filter 4, or can be estimated for example by means of a cartography making it possible to determine the air flow rate by depending on the engine rotation speed and the gas pressure in the intake manifold 32. The intake manifold 32 may be provided with a collector pressure sensor 9 and a gas temperature sensor 11 in the intake manifold.

According to the variant embodiments and depending on the polluting species that one wishes to quantify, the pollutant estimator may also be connected so as to receive, for the purpose of calculating some of the pollutant emissions, the air flow rate. _a i _r, the pressure P i _co gas into the intake manifold, and the temperature T i _co gas into the intake manifold.

The value Q _a i _r can be delivered, instead of a flowmeter at the level of the filter 4, by an estimator of the incoming air flow, using, for example, the cartography mentioned above, as a function of the rotational speed of the engine and the pressure of the gases in the intake manifold 3.

The pollutant estimator 10 delivers one or more values each representing a quantity of polluting species emitted per unit of time. FIG. 1 shows the transmission of a single pollutant emission value "Pollut", which is sent as an input value of a mapping 13. According to the variant embodiments, the Pollut value can represent a flow rate of nitrogen oxides "ΝΟχ", a flow rate of carbon oxides "CO", or a flow rate of unburned hydrocarbons "HC". The estimator 10 can also simultaneously deliver several values corresponding to several polluting emissions. This or these pollutant emission values can be used to adapt the regulation of the engine 1, as illustrated in FIG.

In the example illustrated in FIG. 1, where the pollutant emission value Pollut may for example correspond to a flow of oxides of nitrogen, the Pollut emission level is used as the input value of the map 13, in which a multiplying coefficient Kpoi i is read, which is then sent to a multiplier 16.

The multiplier 16 receives on another input a second coefficient K _N c which is read in a second map 14. The second map 14 has at least two inputs, whose rotation speed N of the engine 1 is a reference torque C, which is determined for example from the signal of an accelerator pedal 12. The setpoint torque C is also used by a calculator 1 5 of reference supercharging pressure, which is configured to calculate a reference supercharging pressure P _cons ruling in the co llecteur inlet 32 in order to obtain the engine 1 C requested torque.

The map 14 can use as a second input value another value related to the torque, for example the reference supercharging pressure P _CO ns.

The multip licateur 16 delivers a control coefficient K _regu i which is used by a controller 8. The controller 1 1 8 receives as input a ε difference between the pressure P i _co gas measured in the co llecteur inlet 32, and the corresponding setpoint pressure P _CO ns delivered by the calculator 15 of the setpoint pressure switch.

The regulator 18 converts this difference ε into a correction value δ sent to a conversion unit 7. The regulator 18 may be of the proportional type, but may also be of proportional integral, proportional derivative or other type of regulator, of PID type. One can also consider other types of controllers, involving corrections not multiplicative and / or functions involving clipping based regulatory coefficients K _regu i received.

It is not departing from the scope of the invention if the combination of the coefficients from maps 1 3 and 14 is other than by a simple multiplication. The coefficient resulting from the mapping 1 3 can for example impose a bound to the coefficient from mapping 14.

The conversion unit 7 is configured to deliver a position command "u" for adapting the geometry of the turbine 5b in order to modify the flow rate passing through the turbine. The value "u" may for example correspond to the blade positions of a variable geometry turbine 5b. The conversion unit 7 uses of course other values than the correction value δ to calculate the position "u" of the actuator of the turbine 5b. These values correspond to calculation methods known from the literature and may in particular comprise a gas temperature measured upstream of the turbine, a flow of gas passing through the turbine and a gas pressure downstream of the turbine.

In general, the internal combustion engine 1 may comprise a pollutant estimator 10, the Pollut estimation of which is taken into account for the calculation of a regulation coefficient K _r allowing the calculation of a "u" position d an actuator for modifying the combustion conditions of the engine 1, and in particular making it possible to evaluate the pressures established inside the gas circuit 30.

In a first embodiment, the estimator 10 calculates a production of nitrogen oxide - by cylinder stroke - using the richness R, the fuel flow Q _ca rb, the ignition advance φ, the water temperature T and engine speed N, according to equation (1):

NOx _mgc = K {Q _carb + Q ₀ φ + φ ₀ τ + T ₀ ) expf - -t ^ ° Î | E quatio n (1)

With:

Qcarb: fuel flow mg / stroke

φ: ignition advance (crankshaft position in degrees) T: engine coolant temperature (degrees Celsius)

R: richness in cylinders (without dimensions) Qo values, (po, T ₀ , Ro, s) are engine-specific calibration parameters, which can be determined by bench tests for a particular engine model.

The value obtained NOX _mgc is expressed for a crankshaft revolution. If we want to convert mass production per unit of time, we can use the conversion formula (valid for a four-stroke and four-cylinder engine):

NOX _mgd = 2.NOX _mgc . Equation (2)

N being the rotational speed of the engine in revolutions / minute.

According to another embodiment which can be combined with the preceding one, the pollutant estimator calculates the carbon monoxide emissions CO _mgc , according to a formula of the type:

If R <R _e

CO _mgc = H. Q _carb . (T + T ₀ ) Equation (3)

If R> R _f

CO _mgc = MiR + R,). Q _carb . (T + T ₀ ) Equation (4)

The values H, R _ls M are engine-specific calibration parameters, which can be determined by bench tests for a particular engine model. The To value can be the same as above for the evaluation of the production of nitrogen oxides.

The value obtained CO _mgc is expressed for a crankshaft revolution. If we want to convert the mass production per unit of time, we can use conversion ormule:

CO mg I s 2.CO "Equation (5)

N being the rotational speed of the engine in revolutions / minute.

According to a third embodiment which can be combined with the first and / or second embodiment, the emission estimator Pollutants calculates unburned hydrocarbon emissions C _mgc , using a formula such as:

Equation (6)

Where T: engine coolant temperature (degrees Celsius)

R: richness in cylinders (without dimensions)

N: the rotation speed of the engine in revolutions / minute

The X value is a reduced variable defined as follows:

Y _ Qai ^' Tool - Q 1 3 - ^MGC' ^ °° ^L

Equation (7) with

® ^air : ^air flow in kg / h

Qair mgc: airflow in mg / shot

P _col : pressure in the co llector [Pa]

T

m ^l : intake manifold temperature in [K]

The values L, T ₀ (pi, d, e, r, p, u, v are specific calibration parameters to the motor which can be determined by bench tests for a mo faithful particular motor. The value T ₀ may to be the same as before.

Of course, the equations (1), (3), (4) and (6) can be replaced by equivalent equations by putting in factor differently the calibration constants.

The value obtained C _mgc is expressed for a crankshaft revolution. If we want to convert mass production per unit of time, we can use the conversion formula:

HC _{mg / s} = 2.HC _mgc . ffl Equation (8) The value obtained C _mgc is expressed for a crankshaft revolution. If we want to convert mass production per unit of time, we can use the conversion formula:

Equation (9)

Equations (1), (3), (4) can be replaced by equivalent equations, where for example the fuel flow is expressed in mg / s instead of expressed in mg / stroke. The terms relating to the fuel flow Q _carb and Q ₀ are then to be taken into account divided by the rotation speed N, and the calibration constants K, H, M are to be adapted, for example by dividing them by 30.

In all previous calculations, the air richness R of the oxidant mixture in the cylinders can be evaluated in different ways. According to a first embodiment, it can be measured by a probe of the "lambda probe" type. The lambda probe is generally placed on the gas circuit 30, downstream of the cylinders and upstream of the possible pollution control system 33. It makes it possible to determine the oxygen richness of the exhaust gases and to deduce the composition of the gas entering the cylinders.

According to another embodiment, the richness R of the gases in the cylinders is calculated by taking into account the flow of air entering and the flow of fuel entering the cylinders. According to the simplest model, one can calculate the richness R of the gases enclosed in the cylinders at the moment of the combustion by

R = Q _carb / Q _alr * PC O Equation (10)

With PC O = fuel comburivore power, PC O = 14.7 for gasoline for example.

Q _carb and Q _a i _r are both expressed here per unit of time, or both "per shot". It can be seen that the pollutant estimator 1 0, using equations (1) and (2) to estimate the production of nitrogen oxide, allows the introduction of an additional control factor in the development of the instruction "u" for the turbine 5b. It is thus possible, for example, during a rise in power of the engine required from the pedal 12, to moderate the rise in power of the engine 1 as a function of the values of nitrogen oxide emissions calculated by the estimator. 1 0: we can for example make this increase in power more progressive, limit the instantaneous emissions, and if possible the global emissions, of nitrogen oxide by the engine 1.

The same type of limitation can be applied, independently or simultaneously, from carbon monoxide emission values calculated from equations (3), (4) and (5).

The pollutant emission estimator 10 may, for example, deliver two separate NOX _mg / _s and CO _mg / _s values giving instantaneous productions of these two pollutants. These values (or their values converted into mass / second) can be sent to two mappings (not shown in FIG. 1) making it possible to read two correction coefficients which will multiply the coefficient K _C delivered by the mapping 14 according to the operating point. of the motor.

A third correction may be added, depending on the amount of unburned hydrocarbons, also calculated by the pollutant estimator, and may be read in a third reading (not shown). ) to extract a dedicated correction coefficient.

Figure 2 illustrates another application of the methods for calculating pollutant emissions according to the invention. FIG. 2 shows a motor equipped with the same sensors as that of FIG. 1, the same sensors being designated by the same references. In Figure 2 however, the air filter 4 is not equipped with a flow meter. The incoming airflow Q _a i _r and the richness R must therefore be evaluated from the data of the other sensors. For this purpose, an air mass estimator 40 is used passing through the intake valves of the cylinders. The estimator comprises a mapping 41 of filling, which gives a filling coefficient η _ν as a function of the pressure

Pcoi measured in the intake manifold 32, rotational speed

N of the engine, and instructions VVTa and VVTe for controlling respectively the intake valves and the cylinder exhaust valves. These instructions may correspond for example to a position at a given moment, or to a phase shift with respect to the passage of the piston of the cylinder by its top dead center.

The estimator 40 may further comprise a map 42 which gives a coefficient η, of "trapping" according to the same four parameters.

Thus, the estimator 40 reads in the map 41:

η _ν = f _v (N, P _pass , WT _a , WT _e ) Equation (1 1)

η _ν : filling factor

and possibly reads in mapping 42

_t = f _t {N, P _col , WT _a , WT _e )

ηί: trapping coefficient (mapped)

An estimate of the incoming airflow Q _a ir _mg c can then be obtained by the following equation:

p

Q _{air mgc} = ^co 'η _ν £ _yl Equation (12)

¹ * I ¹ collar

with

Qair mgc: estimated mass of air passing through the intake valves, in mg "per stroke"

Cyi: maximum internal volume of a cylinder of the engine ("displacement")

And the air mass actually trapped in the cylinders and available for combustion can be estimated by

Oairjiégé = Q air _ _mgc · η, Equation (13)

In FIG. 2, these estimates are obtained by means of a divider 43, sending the ratio P _C o 1 / T _co i to a multiplier 44 receiving on its other input the input coefficient of filling η _ν . The result Q _a ir _mg c is then sent, if necessary, to the estimator 1 0 pollutant emissions, and is sent to another multiplier 45 receiving on its other input the trapping coefficient ηί. The trapped Qair result is sent to the wealth estimator 2 which then estimates the richness R for example according to the formula:

Richness R = ^ ^carb -. PCO Equation (14)

Qair _ trapped

With

PCO: comburivorous fuel (eg 14.7 for gasoline)

The engine 1 of Figure 2 equipped with the estimator 1 0 of pollutant emissions, using the same types of equations as those mentioned above to estimate the level of production of one or more polluting species. The engine 1 is equipped with a trap 33 of nitrogen oxides and a trap monitor 20 configured to trigger "purge" phases of the trap, during which the operating conditions of the engine are such that the oxides of nitrogen accumulated in the trap are reduced, at the cost of temporary overconsumption of engine fuel. In the example illustrated in FIG. 2, the nitric oxide production value is sent to the trap monitor 20, which is a cumulative computing unit, for example using an integrator 21. nitrogen oxide production values calculated by the estimator 10.

The monitor 20 includes a comparator 22 which detects when the total amount of nitrogen oxides accumulated in a delivery system 33 exceeds a threshold referred to herein as "ThresholdCumul".

Until this threshold is reached, the monitor 20 continues to calculate each increment of the total amount stored in the delivery system 33. When the threshold is reached, the trap monitor 20 initiates a procedure 23 which reduces the oxides of nitrogen present in the pollution control system 33. Procedure 23, triggered by a purge control unit, may for example consist of modifying the air / fuel ratios sent to the cylinder as well as the pressures in the gas supply circuit 30, so as to obtain at the cylinder outlet reducing chemical species which will reduce the nitrogen oxides stored in the deposition system 33.

This "purge" mode of operation can typically involve higher temperature combustion, and thus be less expensive to trigger for some modes of operation than for others. The trigger threshold indicated in step 22 may therefore be a function of the instantaneous driving conditions of the vehicle.

In the example illustrated in FIG. 2, the estimation of the total quantity of pollutants accumulated in the deposition system 33 makes it possible to trigger the elimination phases of these pollutants, which are costly in energy, only when these phases are really become necessary.

Figure 3 illustrates yet another example of application of an engine equipped with a system 1 0 estimating pollutants according to the invention. FIG. 3 shows elements that are common to FIGS. 1 and 2, the same elements being designated by the same references.

In the example illustrated in FIG. 3, the vehicle on which the gasoline engine 1 is mounted is also provided with a second electric motor unit 38, comprising for example an electric motor 36 and a battery 37. To arbitrate on the distribution of couples to be provided by the internal combustion engine 1 and the electric motor 36, the vehicle is equipped with a 25 energy management module "LGE" referenced 25.

The torque command C _to t emanating from the pedal 12 is thus transmitted to the energy management module 25 which, depending on the requested torque level, the instantaneous speed of the vehicle, and possibly other parameters, sends a first torque set C ei ec to the electric motor group 38 and a second set point of Ctherm torque to a calculation module 24 involved in the regulation of the heat engine 1.

The arbitration between the amount of torque to be supplied by the electric motor and the amount of torque to be supplied by the heat engine may for example take into account the low efficiency of the engine at moderate torques and reduced speeds, for example when starting the vehicle. which is preferably done with the electric motor 36.

Other elements can of course intervene in the arbitration, such as the level of charge of the battery 37 and / or the reserves of energy available in the battery 37 and in the fuel tank 19.

The computing unit 24, which can act as a moderator module, can send a modified setpoint value C _cons to the energy management module 25, this modified setpoint C _cons being the one that the control systems the engine 1 will actually seek to achieve by acting on various operating parameters, including the position setpoint "u" of the turbine 5b. The energy management module 25 can thus take into account this setpoint modi ed to compensate for the differential between the initial setpoint Ctherm and the modulated setpoint C _cons by increasing or decreasing accordingly the setpoint Ceiec sent to the electric motor 36.

The pollutant estimator 10, again using the equation j 's described previously, can calculate one or more quantities of polluting species which make it possible to read, in one or more maps 26, the correction coefficients of which here only one is represented K _po i ₂ . This corrective coefficient may, for example, multiply the setpoint torque Ctherm sent a priori by the management module 25 to the moderator module 24. A multiplier 27 can thus deliver the modified torque setpoint C _cons on the one hand to the module energy management system 25, and on the other hand, a calculator 15 for boosting the set pressure P _CO ns - P corresponding to the gas pressure to be reached in the intake manifold 32. The set pressure can then be subtracted at a subtractor 29 from the measured pressure P _co i delivered by the pressure sensor 9. The difference to the setpoint ε can be sent to a regulator 8 which can be a regulator of the PID type or another type of regulator and which delivers a regulation value δ to the conversion unit 7 which, using other control parameters as well as to the value δ then develops the position setpoint "u" blades of the turbine 5b.

In the example illustrated in FIG. 3, the pollutant estimator 10 thus makes it possible to optimize the distribution of couples between thermal engines and electric motors, not only on consumption criteria, which are taken into account at the module level. energy management 25, but also to limit the instantaneous emission, and if possible the global emissions, of one or more polluting species.

In the application examples described in FIGS. 1, 2 or 3, which are in no way limiting, a limited number of sensors are used, which sensors are generally already present for other aspects of the control of the heat engine 1. Measurements of these sensors, using the estimator 10, extract information to adapt the control of the internal combustion engine 1 in order to limit the rejuss pollutants thereof. According to the variant embodiments, these sensors may comprise a flowmeter placed to measure the flow of incoming fresh air, or may not include such a flow meter, the estimates of the incoming air flow and of the richness being then, for example, as in the embodiment illustrated in FIG.

It reduces the ecological footprint of the vehicle, by not modifying almost the engine architecture, and without increasing the cost of the vehicle. The sensors used are already present for other engine control stages, and are generally subject to control procedures as the vehicle is being driven, which makes it possible to guarantee the reliability of the data transmitted to the vehicle. pollutant estimator 10. The invention is not limited to the embodiments described, and can be declined in many variants. Thus the richness and flow rates of air entering the cylinders and trapped in the cylinders can be estimated in various ways, corresponding to the embodiment of Figure 1, the embodiment of Figure 2, or other modes of realization. Filling coefficient mapping 41 can be used and no trapping coefficient mapping can be used, considering that it is equal to 1 in first approximation. Only cartography that is already the product of a filler mapping and trapping mapping can be used, and omit the multiplier 44, if for example there is no need to calculate HC production of unburned hydrocarbons. , and therefore no need to know the total flow of air entering the cylinders Q _a i _r .

Claims

1. Internal combustion engine (1) comprising a device (10) for estimating pollutant emissions, the estimating device being configured to calculate a first value (Po llut) of pollutant emissions taking into account the engine speed (N ) of rotation of the engine (1), a measured temperature (T) of coolant circulating in the engine (1), a fuel consumption (Q _ca rb) of the engine, an estimated value (R) indicative of the gas entering the cylinders (6) of the engine, and a level of ignition advance (φ) of the engine.

An engine according to claim 1, wherein the estimating device (10) is configured to calculate a first pollutant value of pollutants as the product of a first affine function of the fuel consumption (Q _ca rb ), a second refining function of the ignition advance (φ), a third affine function of the coolant temperature (T), and a negative exponential term of a power the richness (R) of gas entering the cylinders.

3. Motor according to claim 2, the negative term under the exponential function being proportional to a power function of a difference between the richness (R) of gas entering the engine and a threshold richness.

An engine according to claim 3, wherein the estimating device (10) is configured to calculate a second pollutant value (Pollut) as a product of an affine function of the temperature (T) of the liquid of cooling by the fuel consumption (Qcarb) of the engine, and by a third function refines the richness (R) of the gases entering the cylinders of the engine.

5. Motor according to claim 4, wherein, below a threshold richness, the estimation device (10) is configured to replace the third affine function of the richness (R) of the gases entering the engine cylinders by a constant value.

6. Motor according to any one of claims 3 to 5, wherein the estimating device (10) is further connected to a pressure sensor (9) (P _co i) in an intake manifold (32). of the engine (1) and to a temperature sensor (1 1) (T _co i) of the gases in the intake manifold (32) of the engine, as well as a means (35) for estimating the speed of rotation (N) of the motor (1) and means for estimating (44) the air flow rate (Q _a ir, Qair _mg c) entering the engine (1), and wherein the device (10) emission estimator is configured to calculate a third pollutant value of pollutant emissions, such as a product of an affine function of ignition timing (φ), by an affine temperature function ( T) of coolant, multiplied by a first polynomial of the second degree function of the inverse of the speed (N) of rotation of the motor, by a second polynomial of the second degree depending on the richness (R) , and by a third polynomial of the second degree depending on a reduced variable, the reduced variable being proportional to the air flow rate (Q _a ir, Qair _mg c) entering the engine and to the temperature (Tcoi) of the gases in the intake manifold, and conversely proportional to the pressure (P _co i) of the gases in the intake manifold (32) of the engine.

7. Motor according to any one of the preceding claims, further comprising a regulator (1 8) configured to take into account a signal of an accelerator pedal, and configured to develop from this signal a position command ( u) of an actuator of the motor (1), by weighting the position setpoint (u) with a mapped value (Κ _ρο π) as a function of at least one emission value po lluante (Pollut) calculated by the pollutant emission estimator (10).

8. Motor according to any one of claims 1 to 7, comprising a trap (33) polluting species and an estimation device (10) configured to calculate an instantaneous value (pollut) of pollutant emissions corresponding to the species to trap, the engine (1) further comprising a trap monitor (20) configured to determine the amount (Cumul) accumulated pollutant species in the trap (33) by integrating an estimated value (Pollut) by the estimation device (1 0).

9. Hybrid vehicle comprising an electric machine (36) and comprising an internal combustion engine (1) according to any one of claims 1 to 8, the vehicle comprising an energy management module (25) configured to deliver a set of instructions (Celec) of electric torque to be supplied by the electric machine (36) and to deliver a desired value (Ctherm) of thermal torque to be supplied by the internal combustion engine (1), the vehicle further comprising a moderator module (24) configured to weight the desired value (Ctherm) of thermal torque according to an estimated value (Pollut) of pollutant emissions, and to deliver a setpoint thermal torque (Ccons) for developing a position command (u) of an actuator of the internal combustion engine (1).

A method of managing an internal combustion engine (1), wherein at least one pollutant emission value of a polluting species is estimated using engine parameters other than the gas pressure in the engines. cylinders (6) of the engine (1), at least one polluting emission value being calculated as the product of a first function affine consumption (Q _ca rb) of fuel, a second function refines the advance (φ) on ignition of the engine, a third function refines the temperature (T) of the engine coolant, and a negative exponential term of a power of the richness (R) of the mixture oxidant in the cylinders (6) of the engine.