GB2490943A

GB2490943A - Method for operating an internal combustion engine with electrically powered turbo compressor

Info

Publication number: GB2490943A
Application number: GB1108409.2A
Authority: GB
Inventors: Cesare Maria Meano; Claudio Ciaravino
Original assignee: GM Global Technology Operations LLC
Current assignee: GM Global Technology Operations LLC
Priority date: 2011-05-19
Filing date: 2011-05-19
Publication date: 2012-11-21
Anticipated expiration: 2031-05-19
Also published as: GB201108409D0; GB2490943B

Abstract

Disclosed is a method for operatÂing an internal combustion engine 110 comprising the step of actiÂvating an electrically driven compressor 30 located in an intake pipe 205 of the internal combustion engine 110 during an engine starting phase before the internal combustion engine 110 is supÂplied with fuel. The method provides instant turbo charging of the engine from start up and is particularly useful for idle start-stop type engines where change of mind conditions are likely and in providing instant supercharging during hill starts and other conditions where high engine torque is required at short notice on engine start-up.

Description

A F4ETHCA) FOR OPERATING AN INTERNAL CThIBUSTION ENGINE TEfl FIflD The present invention relates to a method for operating an internal combustion engine, principally an internal combustion engine of a mo-tor vehicle.

More particularly, the present invention relates to a method for op- erating an internal combustion engine during a starting phase the-reof. nmw

It is known that an internal combustion engine starts when it switch-es from an off-condition, in which no fuel is supplied to the engine to an on-condition, in which the fuel is effectively supplied to the engine.

This switching is preceded by a starting phase, in which the internal combustion engine is still in off-condition but it is set in motion by means of an external force, typically by means of a starter motor, until the engine crankshaft reaches a rotational speed sufficient to trigger the combustion of the fuel. :1-

Internal combustion engines for motor vehicle can be currently pro- vided with a turbocharger having the function of increasing the pres-sure of the air entering the engine, in order to enhance the engine torque.

The turbocharger conventionally comprises a turbine located in the exhaust system of the engine, which drives a compressor located in the intake system.

Due to this design, the efficacy of the turbocharger is affected by the so called "turbo lag", which is determined by the time required for the exhaust system driving the turbine to come to high pressure and for the turbine to overcome its rotational inertia and reach the speed necessary for the compressor to effectively increase the air pressure.

During this time, a turbocharged internal combustion engine operates substantially as an aspirated engine, so that the torque generated in this condition depends mainly on the displacement of the engine cy-linders.

For this reason, many turbocharged internal combustion engines, in particular those having small displacement, are generally not able to promptly generate great torque during the first engine cycles after the start of engine.

Hitherto, this drawback has been never considered as a real problem, because the internal combustion engine of a motor vehicle was gener-ally conceived for being started only once at the beginning of each vehicle run.

However, a problem rises in the modem motor vehicles equipped with a start-and-stop system that provides for turning the engine off each time the vehicle stops, for example in proximity of a traffic light or a stop sign, and then for turning it on when the driver wants to move again.

In fact, this system involves that the internal combustion engine is started many times during each vehicle run and that many of these starting phases can be accompanied by the necessity of a prompt ye-hide drive away.

This is particularly true in case of driver's "change of mind", name-ly when the driver has only just caused the engine to stop (due to the start-and-stop system), and suddenly decides to drive away, for example because a traffic light, originally red, has turned suddenly to green.

Another case in which the start of the engine can be accompanied by the necessity of a prompt generation of torque is when the vehicle starts in uphill conditions.

For these reasons, it is an object of an embodiment of the present invention to speed up the capability of an internal combustion en-gine, principally of a turbccharged internal combustion engine, to generate great torque itmiediately after the start of engine.

Another object is that of achieving this goal with a simple, ratio-nale and rather inexpensive solution.

DISCLOSURE

These and other objects are achieved by the embodiments of the inven- tion having the features contained in the independent claims. The de- pendent claim relates to preferred or particularly advantageous as-pects of the embodiments of the invention.

In particular, an embodiment of the invention provides a method for operating an internal combustion engine, which comprises the step of activating an electrically driven corrpressor located in an intake pipe of the internal combustion engine, during an engine starting phase before the internal combustion engine is supplied with fuel.

Thanks to this solution, the pressure of the air entering the engine is advantageously increased still before the engine actually starts, so that the engine is able to generate high torque values also during the first engine cycles after the start.

In particular, the high pressure causes an increased mass of air to enter in the engine cylinders, so that also increased quantities of fuel can be supplied during the first engine cycles, which enhance the enthalpy of the cortustion processes, thereby leading not only to a greater generation of engine torque but also to a faster turbo-charger acceleration and then to a briefer turbo lag, in a "virtuous loop".

According to an aspect of the invention, the electrically driven corn-pressor is activated if a sensed value of a parameter indicative of an engine torque demand exceeds a threshold value thereof.

This aspect has the advantage that the electrically driven compressor is not activated during each starting phase unconditionally, but only when the driver actually demands high torque from the internal corn-bustion engine, for example when a quick drive away is requested, thereby saving fuel and reducing polluting emissions in all the other cases.

According to an aspect of the invention, the above mentioned parame- ter of the engine torque demand is a position of an accelerator de-vice of the internal combustion engine, typically of an accelerator pedal.

As a matter of fact, the position of the accelerator pedal is a para- meters which provide a reliable indication of the engine torque de-manded by the driver.

Therefore, this aspect of the invention has the advantage of irnprov-ing the control of the electrically driven compressor, so that it can be effectively activated only when the start of the internal cornbus-tion engine is accompanied by a great torque demand.

According to another aspect of the invention, the electrically driven compressor can be activated if a sensed value of a velocity of a clutch activation device associated to the internal combustion en-gine, typically of a clutch activation pedal, exceeds a threshold value thereof.

The velocity with which the clutch pedal is moved, typically pressed to disengage the clutch, is not directly related to the engine torque demand but nevertheless provides another reliable indication of whether the driver wants a prompt drive away.

Therefore, also this aspect of the invention allows an effective con-trol of the electrically driven compressor.

According to still another aspect of the invention, the electrically driven compressor is activated if a sensed value of a parameter in-dicative of an inclination, with respect to an horizontal plane, of a vehicle equipped with the internal combustion engine, typically the slope of a road on which the vehicle rests, exceeds a threshold value thereof.

This aspect of the invention has the advantage of allowing a smoother drive away in uphill conditions.

Mother aspect of the invention provides that the electrically driven compressor is activated if an engine crankshaft is currently rotat-ing, for example because the vehicle equipped with the engine is still moving.

Thanks to this solution, the electrically driven compressor can be effectively activated for example when a driver's "change of mind" occurs.

The methods according to the invention can be carried out with the help of a computer program comprising a program-code for carrying out all the steps of the methods described above, and in the form of a computer program product comprising the computer program.

The computer program product can be embodied as an internal combus-tion engine provided with an ECU, a data carrier associated to the ECU, and the computer program stored in the data carrier, so that, when the ECU executes the computer program, all the steps of the me-thod described above are carried out.

The method can be also embodied as an electromagnetic signal, said signal being modulated to carry a sequence of data bits which represent a computer program to carry out all steps of the method.

Another embodiment of the present invention provides an apparatus for operating an internal combustion engine equipped with an electrically driven compressor located in an intake pipe, wherein the apparatus comprises means configured for activating the electrically driven compressor during an engine starting phase before the internal corn-bustion engine is supplied with fuel.

This embodiment of the invention has the advantage of the method men-tioned above, namely that of allowing the internal combustion engine to generate great torque as early as possible after the start of en-gine.

Still another ertodiment provides an automotive system comprising an internal combustion engine (ICE) including at least a cylinder, a fuel injector for injecting fuel into the cylinder, an intake pipe for leading air into the cylinder, an electrically driven compressor located in the intake line, and an electronic control unit (ECU) in communication with the fuel injector, wherein the ECU is configured to activate the electrically driven compressor during an engine starting phase before the internal combustion engine is supplied with fuel.

Also this embodiment of the invention has the advantage of allowing the internal combustion engine to generate great torque as early as possible after the start of engine.

BRIEF D SCRIFICI OF THE DRAWINGS

The present invention will now be described, by way of example, with reference to the accompanying drawings.

Figure 1 shows an automotive system.

Figure 2 is a section of an internal combustion engine belonging to the automotive system of figure 1.

Figure 3 schematically shows an intake system and an exhaust system of the internal combustion engine of figure 1, according to an embo-diment of the invention.

Figure 4 schematically shows an intake system and an exhaust system of the internal combustion engine of figure 1, according to another embodiment of the invention.

Figure 5 is a graph of the torque released by an internal combustion engine during the first engine cycles after the start of engine.

Figure 6 is a flowchart illustrating a first example of an embodiment of the invention.

Figure 7 is a flowchart illustrating a second example of an ernbodi-ment of the invention.

Figure 8 is a flowchart illustrating a third example of an embodiment of the invention.

DETAILED DESCRIPPICR

Some embodiments may include an automotive system 100, as shown in Figures 1 and 2, that includes an internal combustion engine (ICE) 110, in this exanple a Diesel engine, having an engine block 120 de- fining at least one cylinder 125 having a piston 140 coupled to ro-tate a crankshaft 145. A cylinder head 130 cooperates with the piston 140 to define a combustion chamber 150. A fuel and air mixture (not shown) is disposed in the combustion chamber 150 and ignited, result-ing in hot expanding exhaust gasses causing reciprocal movement of the piston 140. The fuel is provided by at least one fuel injector and the air through at least one intake port 210. The fuel is provided at high pressure to the fuel injector 160 from a fuel rail in fluid corrinunication with a high pressure fuel pump 180 that increase the pressure of the fuel received through a fuel source 190.

Each of the cylinders 125 has at least two valves 215, actuated by a camshaft 135 rotating in time with the crankshaft 145. The valves 215 selectively allow air into the combustion chamber 150 from the port 210 and alternately allow exhaust gases to exit through a port 220.

In some examples, a cam phaser 155 may selectively vary the timing between the camshaft 135 and the crankshaft 145.

The air may be distributed to the air intake port(s) 210 through an intake manifold 200. In other embodiments, a throttle body 330 may be provided to regulate the flow of air into the manifold 200.

According to the scheme of figure 3, an air intake duct 205 may pro-vide air from the ambient environment to the intake manifold 200. In still other embodiments, a forced air system such as a turbocharger 230, having a compressor 240 rotationally coupled to a turbine 250, may be provided. Rotation of the compressor 240 increases the pres-sure and temperature of the air in the duct 205 and manifold 200. A intercooler 260 disposed in the duct 205 may reduce the temperature of the air. The turbine 250 rotates by receiving exhaust gases from an exhaust manifold 225 that directs exhaust gases from the exhaust ports 220 and through a series of vanes prior to expansion through the turbine 250. The exhaust gases exit the turbine 250 and are di- rected into an exhaust system 270. This example shows a variable geo-metry turbine (VGT) with a VGT actuator 290 arranged to move the vanes to alter the flow of the exhaust gases through the turbine 250.

In other embodiments, the turbocharger 230 may be fixed geometry and/or include a waste gate.

The exhaust system 270 may include an exhaust pipe 275 having one or more exhaust aftertreatment devices 280. The aftertreatment devices may be any device configured to change the composition of the exhaust gases. Some examples of aftertreatment devices 280 include, but are not limited to, catalytic converters (two and three way), oxidation catalysts, lean NOx traps, hydrocarbon adsorbers, selective catalytic reduction (5CR) systems, and particulate filters. As shown in figure 1, other embodiments may include an exhaust gas recirculation (EGR) system 300 coupled between the exhaust manifold 225 and the intake manifold 200. The EGR system 300 may include an EGR cooler 310 to re-duce the temperature of the exhaust gases in the EGR system 300. An EGR valve 320 regulates a flow of exhaust gases in the EGR system 300.

The automotive system 100 may further include an electronic control unit (ECU) 450 in coiwriunication with one or more sensors and/or de- vices associated with the ICE 110. The ECU 450 may receive input sig- nals from various sensors configured to generate the signals in pro-portion to various physical parameters associated with the ICE 110.

The sensors include, but are not limited to, a mass airflow and tem-perature sensor 340, a manifold pressure and temperature sensor 350, a combustion pressure sensor 360, coolant and oil temperature and level sensors 380, a fuel rail pressure sensor 400, a cam position sensor 410, a crank position sensor 420, exhaust pressure and temper-ature sensors 430, and an EGR temperature sensor 440. Furthermore, the ECU 450 may generate output signals to various control devices that are arranged to control the operation of the ICE 110, including, but not limited to, the fuel injectors 160, the throttle body 330, the EGR Valve 320, the VGT actuator 290, and the cam phaser 155.

Note, dashed lines are used to indicate communication between the ECU 450 and the various sensors and devices, but some are omitted for clarity.

Turning now to the ECU 450, this apparatus may include a digital cen-tral processing unit (CPU) in communication with a memory system and an interface bus. The CPU is configured to execute instructions stored as a program in the memory system, and send and receive sig-nals to/from the interface bus. The memory system may include various storage types including optical storage, magnetic storage, solid state storage, and other non-volatile memory. The interface bus may be configured to send, receive, and modulate analog and/or digital signals to/from the various sensors and control devices. The program may embody the methods disclosed herein, allowing the CPU to carryout out the steps of such methods and control the ICE 110.

The whole automotive system 100 is mounted on a motor vehicle, which is indicated with 60 in figure 3 and 4.

According to the present embodiment of the invention, the intake duct 205 is further equipped with an electrically driven compressor (e-compressor) 30, which can be either of volumetric or aerodynamic type.

As a matter of fact, a compressor is a mechanical device that gener-ally comprises an external housing having an inlet and an outlet for a gaseous stream, and a movable component that is accommodated inside the external housing, so as to increase the pressure of that gaseous stream.

In a volumetric compressor, the movable component is arranged in the external casing so as to delimit one or more operating chambers, and to alternatively open these chambers to the inlet and to the outlet, so as to cause a cyclical transfer of a certain quantity of gas from the inlet to the outlet, while preventing the gas to flow back. In some embodiments, whilst the chamber is closed for both the inlet and the outlet, the motion of the movable component causes the internal volume of the operating chamber to decrease, so as to further com-press the gas contained therein. Typical volumetric compressors are for example the alternative compressors (comprising a piston that re-ciprocates in a cylinder), the rotary screw compressors, the rotary vane compressors, Roots compressors, Lysholm compressors, G-Lader scroll-type compressors, etc..

In an aerodynamic compressor, the movable component is a rotor or ira-peller equipped with vanes that add kinetic-energy/velocity to the gaseous stream flowing through the external casing. This kinetic energy is then converted to an increase of static pressure by slowing the flow through a diffuser, which is generally located at the outlet of the external casing. Typical volumetric compressors are for exam-ple the centrifugal compressors.

An e-compressor according to the present errbodiment of the invention can be a conventional compressor, either of volumetric or aerodynamic type, which further comprises an electric motor (not shown) provided for driving its movable component.

The electric motor of the e-compressor 30 can be powered by a battery (not shown) of the motor vehicle 60 via a suitable electric circuit.

Possibly, the electric circuit can comprise super-capacitors that are charged by the battery, so as to power the electric motor of the e-compressor 30 with higher starting currents.

The operation of the e-compressor 30, in particular the activation and deactivation of its electric motor via the electric circuit, is controlled by the ECU 450 according to a strategy that will be ex-plained hereafter. Possibly, a dedicated auxiliary control unit can be used to control the operation of the e-compressor 30, instead of the ECU 450.

With reference to the direction of the inducted air, the e-compressor can be located either downstream (as shown in figure 1) or alter-natively upstream of the turbocharger compressor 240 (as shown in figure 2).

As a matter of fact, the e-conpressor 30 located upstream of the tur-bocharger compressor 240 has the advantage of compressing air that is fresher than that compressed by the e-compressor 30 located down-stream, thereby improving the combustion processes within the engine cylinders 125. Conversely, the e-compressor 30 located downstream of the turbocharger compressor 240 has the advantage of compressing air that is directly fed into the intake manifold 200, without any rele-vant pressure loss.

In both cases, the e-compressor 30 is connected in parallel with a bypass valve 18, which opens when the turbocharger 230 reaches an ap- propriate rotational speed, thereby allowing the incoming air to by-pass the e-cornpressor 30.

The ICE 110 is generally provided for driving a group of wheels of the vehicle 60.

This group of vehicle wheels is connected to the ICE 110 by means of a mechanical transmission (not shown), which comprises a gear box and a clutch suitable for engaging and disengaging the gear box from the engine crankshaft 145.

According to the present explanatory embodiment of the invention, the mechanical transmission is manual and comprises a lever 40, provided for the driver to manually shifting the gears, and a clutch pedal 41, provided for activating the clutch.

In particular, the clutch is configured so that the engine crankshaft is disengaged from the gear box when the clutch pedal 41 is pressed, whereas they are mutually engaged when the clutch pedal 41 is released.

The ICE 110 is controlled by means of the engine control unit (ECU) 450, which is particularly provided for regulating the quantity of fuel injected by the fuel injectors 160, on the basis of the position of an accelerator pedal 42 that is pressed by the driver.

According to the present embodiment of the invention, the ECU 450 further implements a start-and-stop strategy, which generally pro-vides for automatically turning the ICE 110 off each time the vehicle stops, for example in proximity of a traffic light or a stop sign, and then for automatically turning it on when the driver wants to drive away.

In greater detail, the ICE 110 is turned off when the driver releases the clutch pedal 41 after having shifted the transmission lever 40 in an idle position, namely a position in which the gear box does not transmit any motion from the engine crankshaft 145 to the vehicle wheels.

More precisely, this stopping manouvre causes the ECU 450 to present- ly prevent the fuel injectors 160 to inject fuel into the engine cy-liriders 125 and consequently the ICE 110 to stop.

Thereafter, the ICE 110 is turned on when the driver presses the clutch pedal 41 again, in order to shift the transmission lever 40 to engage the first gear.

More precisely, this startup manouvre triggers a starting phase in which the ICE 110 is still in off-condition but it is set in motion by means of an external force, typically by means of a starter motor (not shown), until the engine crankshaft 145 reaches a rotational speed sufficient to trigger the contustion of the fuel, whereupon the ECU 450 effectively corrunands the fuel injectors 160 to supply fuel, thereby actually starting the ICE 110.

The e-corrpressor 30 is activated by the ECU 450 during this starting phase, before the fuel injectors 160 begin to supply fueL Once the e-compressor 30 is activated, the ECU 450 keeps it active at least until the end of the starting phase, namely until the injection of fuel actually starts. Preferably, the e-cornpressor 30 is kept active also for a brief period after the start of injection, thereby allow-ing a greater amount of fuel to be injected.

While the e-corrtpressor 30 is active, the bypass valve 18 is closed.

When the fuel injection starts, the e-corrpressor 30 is turned off and the bypass valve 18 is opened.

Thanks to this solution, the e-cornpressor 30 increases the pressure of the inducted air, so that the ICE 110 will promptly generate more torque even during the first engine cycles after the beginning of fuel injection, while the turbocharger 230 is still less effective.

In greater detail, the high pressure generated by the e-compressor 30 S increases the mass of air entering the engine cylinders 125 during the above named first engine cycles, so that also the fuel injected quantities can be advantageously increased.

In this way, the enthalpy of the combustion processes is advanta-geously enhanced, thereby allowing the ICE 110 not only to promptly generate torque but also to achieve a faster acceleration of the tur-bocharger 230 and thus to reduce the turbo lag.

The benefit of this strategy is illustrated in figure 5, which shows in continuous line A the torque generated during the first engine cycles by the ICE 110 started with the aid of the e-corrpressor 30, and in dotted line B the torque that the same ICE 110 would release if the e-compressor 30 was absent or not active.

According to the present embodiment of the invention, the e-compressor 30 can be activated during each starting phase of the ICE unconditionally, or it can be activated only under certain condi-tions, such those explained in the examples below.

According to an example illustrated in figure 6, the ECU 450 is pro- vided for checking whether the starting phase of the ICE 110 is ac-tually accompanied by a request of a prompt drive away or not.

Therefore, before the startup manouvre is completed, the ECU 450 senses a value TD of a parameter indicative of the above mentioned promptness and then activates the e-compressor 30 only if the value TO exceeds a predetermined threshold value TDb, thereof, otherwise the c-compressor 30 is kept inactive and the ICE 110 is started conven-tionally.

The above mentioned parameter can be the position of the accelerator pedal 42, which basically represents an engine torque demanded by the driver, or the velocity with which the clutch pedalS 41 is pressed to release the clutch during the startup rnanouvre. In these cases the accelerator pedal 42 or the clutch pedal 41 should be equipped with a position sensor (potentiometer) connected to the ECU 450.

This strategy has the advantage that the e-compressor 30 is activated only when a quick drive away is requested, thereby saving fuel and reducing polluting emissions in all the other cases.

According to another example illustrated in figure 7, the ECU 450 is provided for checking whether the starting phase of the ICE 110 is triggered while the engine crankshaft 145 is motionless or still ro-tating.

As a matter of fact, the first condition represents the conventional case in which the vehicle 60 is motionless when the driver decides to drive away, whereas the second condition represents a typical case of driver's "change of mind", that is a case in which the driver has al-ready completed the stopping manouvre and suddenly decides to drive away, so that he performs the startup manouvre while the vehicle 60 is still moving.

In view of the above, if the startup manouvre is completed while the engine crankshaft 145 is motionless, then the e-compressor 30 is kept inactive and the ICE 110 is started conventionally.

If conversely the startup manouvre is completed while the engine crankshaft 145 is still rotating, then the ECU 450 activates the e-compressor 30, in order to allow the ICE 110 to promptly generate torque.

In this latter case, the ECU 450 further determines if the ICE 110 can be restarted by simply restart the fuel injection, or if it is necessary to activate also the start motor to accelerate the engine crankshaft 145.

According to a third example illustrated in figure 8, the ECU 450 is provided for checking whether the starting phase of the ICE 110 oc-curs while the vehicle 60 is in uphill condition or not.

More precisely, before the startup manouvre is completed, the ECU 450 senses a value IV of a parameter indicative of an inclination of the vehicle 60 with respect to a generic horizontal plane, and then acti- vates the e-compressor 30 only if the value IV exceeds a predeter-mined threshold value IV thereof, otherwise the e-cornpressor 30 is kept inactive and the ICE 110 is started conventionally.

The parameter indicative of the vehicle inclination can be the slope of the road on which this vehicle 60 rests, and can be measured by a longitudinal accelerometer located on the vehicle 60 itself, for ex-ample integrated in an airbag or in an Electronic Stability Program (ESP) system.

According to an aspect of the invention, the strategies described above are performed by the ECU 450, with the aid of a computer pro-gram stored in a data carrier 101 connected to the ECU 450, so that when the ECU 450 runs the program all the steps of the strategies are carried out.

It should be understood that the strategies described above can be also combined each other, in order to achieve a more effective con-trol of the e-cornpressor 30.

It should also be understood that the strategies described above can be effectively performed even if the vehicle' s transmission is auto-matic and the start-and-stop strategy accordingly configured for an automatic transmission.

While at least one exemplary embodiment has been presented in the foregoing surrimary and detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only exam- ples, and are not intended to limit the scope, applicability, or con- figuration in any way. Rather, the foregoing surrimary and detailed de-scription will provide those skilled in the art with a convenient road map for implementing at least one exemplary embodiment, it being understood that various changes may be made in the function and ar-rangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents.

REFES

18 Bypass valve e-compressor 40 transmission lever 41 clutch pedal 42 accelerator pedal motor vehicle automotive system 101 data carrier internal combustion engine engine block cylinder cylinder head 135 camshaft piston crankshaft combustion chamber cam phaser 160 fuel injector fuel rail fuel pump fuel source intake manifold 205 air intake duct 210 intake pcrt 215 valves 220 port 225 exhaust manifold 230 turbocharger 240 compressor 250 turbine 260 intercooler 270 exhaust system 275 exhaust pipe 280 aftertreatment devices 290 VGT actuator 300 exhaust gas recirculation system 310 EGR cooler 320 EGR valve 330 throttle body 340 mass airflow and temperature sensor 350 manifold pressure and temperature sensor 360 combustion pressure sensor 380 coolant and oil temperature and level sensors 400 fuel rail pressure sensor 410 cam position sensor 420 crank position sensor 430 exhaust pressure and temperature sensors 440 EGR temperature sensor 450 ECU aanc

Claims

1. A method for operating an internal combustion engine (110), corn-prising the step of activating an electrically driven compressor (30) located in an intake pipe (205) of the internal combustion engine (110), during an engine starting phase before the internal combustion engine (110) is supplied with fuel.

2. A method according to claim 1, wherein the electrically driven compressor (30) is activated if a sensed value of a parameter in-dicative of an engine torque demand exceeds a threshold value thereof.

3. A method according to claim 2, wherein the parameter is a posi- tion of an accelerator device (42) of the internal combustion en-gine (110).

4. A method according to claim 1, wherein the electrically driven compressor (30) is activated if a sensed value of a velocity of a clutch activation device (41) associated to the internal combus-tion engine (110) exceeds a threshold value thereof.

5. A method according to claim I, wherein the electrically driven compressor (30) is activated if a sensed value (IV) of a pararne-ter indicative of an inclination of a vehicle (60) equipped with the internal combustion engine (110) exceeds a threshold value (IVb,) thereof.

6. A method according to claim 1, wherein the electrically driven compressor (30) is activated if an engine crankshaft (145) is to-tating.

7. A computer program comprising a computer code suitable for per-fonning the method according to any of the preceding claims.

8. A computer program product on which the computer program of claim 7 is stored.

9. An internal combustion engine (110) comprising an engine control unit (450), a data carrier (101) associated to the engine control unit (450), and a computer program according to claim 7 stored in the data carrier (101).

10. An electromagnetic signal modulated as a carrier for a sequence of data bits representing the computer program according to claim 7.

11. An apparatus for operating an internal combustion engine (110) equipped with an electrically driven compressor (30) located in an intake pipe (205), wherein the apparatus comprises means (450) configured for activating the electrically driven compressor (30) during an engine starting phase before the internal combustion engine (110) is supplied with fuel.

12. An automotive system (100) comprising: an internal combustion engine (110) including a cylinder (125), a fuel injector (160) for injecting fuel into the cylinder (125), an intake pipe (205) for leading air into the cylinder (125), an electrically driven compressor (30) located in the intake pipe (205), and an electronic control unit (ECU) in corranunication with the fuel injector (160), wherein the ECU (450) is configured to activate the electrically driven compressor (30) during an engine starting phase before the internal combustion engine (110) is supplied with fuel.