GB2500928A - Optimising ammonia generation in an exhaust system having a lean NOx trap and a selective catalytic reduction system - Google Patents

Abstract

A method of optimising ammonia generation in an exhaust system (270, fig 1) of an internal combustion engine 100, the exhaust system comprising at least two after-treatment devices (280, fig 1), the after-treatment devices being at least a lean NOx trap 281 and a selective catalytic reduction system 282 or a selective catalytic reduction system comprising a particulate filter 283, the method comprising: predicting or measuring (20, fig 6) the present ammonia production from said lean NOx trap 281 during its regeneration phase under rich combustion conditions, comparing (21, fig 6) said present ammonia production with an optimal ammonia production needed by the selective catalytic reduction system 282, 283 and acting on at least one parameter, such as a target value air/fuel ratio and/or end criteria (23, fig 7) influencing said lean NOx trap regeneration phase, to reach the optimal ammonia production.

Description

METHOD OF OPTIMIZING AMMONIA GENERATION INAN EXHAUST SYSTEM OF

AN INTERNAL COMBUSTION ENGINE

TECHNICAL FIELD

The present disclosure relates to a method of optimizing ammonia generation in an exhaust system of an internai combustion engine.

BACKGROUND

It is known that the exhaust gas after-treatment systems of a Diesel engine can be provided, among other devices, with a Lean NO Trap (LNT).

A Lean NO Trap (LNT) is provided for trapping nitrogen oxides NO contained in the exhaust gas and is located in the exhaust line.

A LNT is a catalytic device containing catalysts, such as Rhodium, Platinum and Palladium, and adsorbents, such as barium based elements, which provide active sites suitable for binding the nitrogen oxides (NOr) contained in the exhaust gas, in order to trap them within the device itself.

Lean NO Traps (LNT) are subjected to periodic regeneration processes, whereby such regeneration processes are generally provided to release and reduce the trapped nitrogen oxides (NOr) from the LNT.

The LNT are operated cyclically, for example by switching the engine from lean-bum operation to operation whereby an excess amount of fuel is available, referred also as rich operation or regeneration phase. During normal operation of the engine, the NO are stored on a catalytic surface. When the engine is switched to rich operation, the NO stored on the adsorbent site react with the reductants in the exhaust gas and are desorbed and converted to nitrogen and ammonia, thereby regenerating the adsorbent site of the catalyst.

LU

In the art are also known exhaust gas treatment systems for the emissions reduction and in particular of particulates and oxides of nitrogen (NOt) from the diesel engine exhaust gas. These systems are provided with after-treatment devices installed along the exhaust line of the engine and typically comprise a diesel particulate filter (DPF) for control of particulates, and selective catalytic reduction (SCR) system for NOx control.

It is also known in the art, in some exhaust system configuration, to inject a reagent (catalyst) fluid in the exhaust line of the diesel engine in order to reduce emissions by means of the afore-mentioned aftertreatment devices. In particular, hydrocarbon based 2C reagents1 generally indicated as HC, like the same diesel fuel used for fuelling the engine, are injected in the exhaust line in order to promote the regeneration of diesel particulate filter (DPF) with the burning of soot accumulated therein. Furthermore, a fluid catalyst such as urea, or ammonia, or a combination thereof (generally in a water solution) are also injected into the exhaust line of the diesel engine in order to promote the reduction of nitrogen oxides (NOx) in the selective catalytic reduction system (SCR).

1-lydrocarbon (HC) and the urea catalyst are injected into the exhaust gas produced by the engine by means of two separate injectors installed in the exhaust line.

Such a configuration, due to the number of components, and in particular the number of injectors needed for delivery hydrocarbon and urea in the exhaust line, leads to an high system complexity, high costs of production, and also to a reduced installation flexibility of the exhaust gas treatment system.

A possible simplification of such complex exhaust system is to combine a Lean NOx i rap (LIN I) upstream to a irii siorage aevice (a UR, seiective cataiytic reaucuon system or a SCRF, a particulate filter comprising a selective catalytic reduction system).

The big potential of such architecture would be from one side the reduction of the after-treatment device numbers and on the other side the fact that an external urea/ammonia injector would not be needed anymore. In fact, during rich operation, the NO stored on the adsorbent site react with the reductants in the exhaust gas and are desorbed and converted to nitrogen and ammonia too.

The generated ammonia could be advantageously used for the downstream SCR/SCRF to remove excess NOx, while the filter removes particulate mailer. In such a way, no urea injector is needed (see fig. 3), thus allowing a cheaper exhaust system architecture.

It has to be said the ammonia generation must be carefully controlled: a lower amount of it is insufficient to help performing the complete nitrogen reduction without any external catalyst injection, while a higher amount causes an ammonia slip downstream the SCR or the SCRF.

Document LSAE International N. 2011-01-0305" discloses a laboratory study performed to assess the effectiveness of LNT+SCR systems for NO control in lean exhaust. The effects of the catalyst system length and the spatial configuration of the LNT & 8CR catalysts were evaluated for their effects on the NO conversion, NH3 yield, N20 yield, and HC conversion. No mention is done in such document how to control the ammonia generation.

Document "S.A.E. International N. 2011-01-0305" discloses Diesel NOx emissions control utilizing combined Lean NOx Trap (LNT) and so-called passive or in-situ Selective CataiyticReduction (8CR) catalyst technologies (i.e. with reductant species generated by the LNT). Even if the article explicitly discloses the fact that reductant specie are generated by the LNT, no mention is done, how to control the ammonia generation.

Therefore a need exists for a method that optimizes ammonia generation during the rich phase, i.e. during the regeneration process of the LNT.

An object of this invention is to provide a method which optimizes the exhaust architecture, combining a Lean NOx Trap (LNT) upstream to a SCR or a SCRF. In particular, the optimization is related to the management of the rich combustion mode, to generate the right ammonia production.

Another object is to provide an apparatus which allows to perform the above method.

These objects are achieved by a method, by an apparatus, by an engine, by a computer program and computer program product, and by an electromagnetic signal having the features recited in the independent claims.

The dependent claims delineate preferred andlor especially advantageous aspects.

SUMMARY

An embodiment of the disclosure provides a method of optimizing ammonia generation in an exhaust system of an internal combustion engine of an automotive system, the exhaust system comprising at least two after-treatment devices, the after-treatment devices being at least a lean NOx trap and a selective catalytic reduction system or a particulate filter comprising a selective catalytic reduction system, the method comprising: predicting or measuring the present ammonia production from said lean NOx trap during its regeneration phase under rich combustion conditions, * comparing said present ammonia production with an optimal ammonia production needed by the selective catalytic reduction system and in case the present ammonia production is higher or lower than the optimal ammonia production, acting on at least one parameter, influencing said lean NOx trap regeneration phase, to reach the optimal ammonia production.

Consequently, an apparatus is disclosed for optimizing ammonia generation in an exhaust system of an internal combustion engine of an automotive system, the apparatus comprising: * means for predicting or measuring the present ammonia production from said lean NOx trap during its regeneration phase under rich combustion conditions, * means for comparing said present ammonia production with an optimal ammonia production needed by the selective catalytic reduction system and in case the present ammonia production is higher or lower than the optimal ammonia production, * means for acting on at least one parameter, influencing said lean NOx trap regeneration phase, to reach the optimal ammonia production.

An advantage of this embodiment is that it provides a method of optimizing ammonia generation in an exhaust system, thus allowing not to use any external injection of urea for the downstream SCPJSCRF.

Moreover, the method will allow to use only two after-treatment devices, thus bringing further advantages: * further NOx emission reduction, due to the enhancement of NOx storage at low temperature by means of LNT and to additional NOx removal by means of the downstream SCRF; * the optimization of both LNJT and SCRF volumes, would further allow to lower the cost of the LNT catalyst by reducing its rhodium content; * potential to reduce the problem of H2S emissions from LNT, since the downstream SCR/SCRF functiorialities might be useful to this scope.

* packaging reduction: compared to the current after-treatment architectures, this solution offers a reduced number of substrates and canning boxes and, being lighter, potential to reduce C02 emissions and backpressure. Moreover, it allows the urea tank removal.

According to a further embodiment of the invention, the parameter, which influences the lean NOx trap regeneration phase, is one of the possible end criteria of the lean NOx trap regeneration phase.

An advantage of this embodiment is that it provides an easy way to control ammonia generation, without any additional hardware requirement.

According to an aspect of such embodiment, if the present ammonia production is lower than the optimal ammonia production, the end criteria of the lean NOx trap regeneration phase are modified by increasing the fime of the regeneration phase under rich combustion conditions.

According to a further aspect of such embodiment, if the present ammonia production is higher than the optimal ammonia production, the end criteria of the lean NOx trap regeneration phase are modified by interrupting the regeneration phase under rich combustion conditions.

According to a further embodiment of the invention, the parameter, which influences the lean NOx trap regeneration phase, is a target value of the ratio air/fuel.

An advantage of this embodiment is that it also provides an easy way to control ammonia generation, without any additional hardware requirement.

According to an aspect of such embodiment, if the present ammonia production is lower than the optimal ammonia production, the target value of the ratio airtfuel is reduced.

According to a further aspect of such embodiment, if the present ammonia production is higher than the optimal ammonia production, the target value of the ratio air/fuel is increased, by interrupting the regeneration phase under rich combustion conditions.

According to a still further embodiment of the invention, the parameter, which influences the lean NOx trap regeneration phase, is one of the possible criteria to activate the lean NOx trap regeneration phase.

An advantage of this embodiment is that it also provides an easy way to control ammonia generation, without any additional hardware requirement.

According to an aspect of such embodiment, possible criteria to activate the lean NOx trap regeneration phase are temperature, NOx engine-out amount, NOx stared amount and/or space velocity.

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

The computer program product can be embodied as a control apparatus for an internal combustion engine, comprising an Electronic Control Unit (ECU), a data carrier associated to the ECU, and the computer program stored in a data carrier, so that the control apparatus defines the embodiments described in the same way as the method. In this case, when the control apparatus executes the computer program all the steps of the method described above are carried out.

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

A still further aspect of the disclosure provides an internal combustion engine specially arranged for carrying out the method claimed.

BRiEF DESCRIPTION OF THE bRAWl NGS

The various embodiments will now be described, by way of example, with reference to the accompanying drawings, in which: 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 is a schematic view of the after-treatment system according to the invention.

Figure 4 is a graph depicting the behavior of the ammonia generation with respect to the duration of the single event and the lambda value is shown Figure 5 is a flowchart of a method for otpimzing ammonia generation in an internal combustion engine, according to an embodiment of the invention.

Figure 6 is a detail of the flowchart in Fig. 5.

DETAILED DESCRIPTION OF THE DRAWINGS

Some embodiments may include an automotive system 100, as shown in Figures land 2, that includes an internal combustion engine (ICE) 110 having an engine block 120 defining at least one cylinder 125 having a piston 140 coupled to rotate 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, resulting in hot expanding exhaust gasses causing reciprocal movement of the piston 140. The fuel is provided by at least one fuel injector 160 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 170 in fluid communication with a high pressure fuel pump 180 that increase the pressure of the fuel received 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.

An air intake duct 205 may provide air from the ambient environment to the intake manifold 200. In other embodiments, a throttle body 330 may be provided to regulate the flow of air into the 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 pressure and temperature of the air in the duct 205 and manifold 200. An 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 directed into an exhaust system 270. This example shows a variable geometry 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 andlor 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 281, hydrocarbon adsorbers, selective catalytic reduction (8CR) systems 282, particulate filters (DPF) or a combination of the last two devices, i.e. selective catalytic reduction system comprising a particulate filter (SCRF) 283. 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 reduce 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 communication with one or more sensors and/or devices associated with the ICE 110 and equipped with a data carrier 40. The ECU 450 may receive input signals from various sensors configured to generate the signals in proportion to various physical parameters associated with the ICE 110. The sensors include, but are not limited to, a mass airflow and temperature sensor 340, a manifold pressure and temperature sensor 350, a combustion pressure sensor 360, coolant and oil temperature and level sensors 360, a fuel rail pressure sensor 400, a cam position sensor 410, a crank position sensor 420, exhaust pressure and temperature sensors 430, an EGR temperature sensor 440, and an accelerator pedal position sensor 445. 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 tines 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 central 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 signals 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.

Turning back to exhaust system 270, the proposed invention relies on the optimization of the after-treatment system, which features the combination of two NOx after-treatment devices. The combined system consists (Fig. 3) of an upstream LNT 281 and a downstream 5CR 282 or SCRF (SCR on EWE) 283 positioned in all possible close-coupled and/or under floor configurations.

Preferably, the first catalyst could be positioned as close as possible to the exit of the turbocharger to take advantage of the high temperature conditions which are beneficial for both LNT and SCR/SCRF. in -L Li

the LNT reduces engine-out exhaust gas constituents (CO and HC) with high efficiency and stores NOx during lean operating conditions. During rich operating conditions, the NOx is released and converted.

However during rich operating conditions, NH3 (ammonia) is also generated even though this is not typically monitored when the LNT catalyst is used as stand alone or with a downstream DPF. The amount of generated ammonia depends on the specific management of the rich combustion conditions, as for example the lambda value, the duration of each single DeNOx events and the temperature conditions.

Experimental activities on the actual LNT technology have been performed in order to assess the real capability to generate ammonia. This activity demonstrates the possibility to manage ammonia production in rich combustion mode.

Such results indicate that: -the higher the duration of the single event, the higher the NH3 generation -the lower the lambda value (the higher the 1-ICs & H2 amount), the higher the NH3 generation -the higher the temperature in front of LNT, the higher the NH3 generation S -the higher the space velocity, the higher the NH3 generation -the higher the NOx amount1 the higher the NH3 generation In Fig. 4, for example, the behavior of the ammonia generation with respect to the duration of the single event and the lambda value is shown.

In general, as shown in Fig. 5, the ammonia production by the LNT during the rich combustion mode could be monitored by means of a specific sensor (i.e Nh3/NOx dual sensor) 284 placed upstream the SCRE. In this way, it will be possible to quantify the amount of NH3 arriving at the SCRF, independently of the LNT technology.

A second specific sensor 285, placed downstream of the SCRF, monitors the amount of NH3 slipping through the SCRF. Thus, combining the information from the two sensors, it will be possible to monitor the present ammonia production stored into the SCRF.

Depending on the calibration status and the extensive knowledge and characterization of the LNT washcoat, the present ammonia production could eventually be predicted and mapped in rich combustion mode. Thus, the sensor 284 upstream the SCR/SCRF could be avoided.

The SCRISCRF stores the ammonia released from the LNT catalyst. The ammonia stored over the SCR/SCRF contributes to an additional reduction of NOx which are not converted through the LNT catalyst. As consequence, the LNT catalyst formulation could be changed reducing the amount of Rhodium. The sensor placed downstream the SCRISCRF monitors simultaneously the amount of NOx not converted and the amount of ammonia slipping through the SCRF.

Turning to Fig. 6, according to a preferred embodiment, the method of optimizing ammonia generation comprises the following steps: -predicting or measuring 20 the present ammonia production from said lean NOx trap 281 during its regeneration phase under rich combustion conditions, 10. comparing 21 said present ammonia production with an optimal ammonia production needed by the selective catalytic reduction system 282, 283 and in case the present ammonia production is higher or lower than the optimal ammonia production, -acting 22 on at least one parameter 23, 24, 25, influencing said lean NOx trap regeneration phase, to reach the optimal ammonia production.

In particular, block 20 represents the way how the ammonia generation is measured or modelled, as mentioned above. Block 21 represents the conditions determining the optimal production of the ammonia: SCRJSCRF specifications and other parameters (e.g. NC poisoning on SCRF, fuel penalty). Block 22 (see also the same block 22 in greater detail in Fig. 7), represents the procedure to manage the regeneration phase of the LNT.

The sub black 26 shows the sequence "engine operating conditions, start of the regeneration, regeneration, end of the regeneration, successful event". The regeneration is enabled under the conditions of sub block 25, either the determination of the best conditions or the maximum NIOx engine-out emissions. These are determined by several parameter, among others, temperature, NOx engine-out amount, NOx stored amount, space velocity (depending on exhaust gas temperature and flowrate and exhaust pipe 275 characteristics). Block 24 represents the air/fuel target value and block 23 are the end criteria of the regeneration event: fixed time, adaptive time, lambda breakthrough.

By acting on one of the three blocks 23-25 to control ammonia generation, there is the big advantage not to use any further hardware but just to interact with the existing control method of the [NT regeneration phase.

In particular, by acting on the end criteria 23 would be possible, if the present ammonia production is insufficient, to increase the time of the regeneration phase under rich combustion conditions, while if the present ammonia production is higher than the optimal ammonia production, the end criteria 23 of the lean NOx trap regeneration phase are modified by interrupting the regeneration phase under rich combustion conditions.

If the chosen parameter is the target value of the ratio air/fuel 24, if the present ammonia production is lower than the optimal ammonia production, the target value of the ratio air/fuel 24 would be reduced, while, if the present ammonia production is higher than the optimal ammonia production, the target value of the ratio air/fuel 24 would be increased, by interrupting the regeneration phase under rich combustion conditions.

While at least one exemplary embodiment has been presented in the foregoing summary 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 examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those 1.6 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 arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents.

REFERENCE NUMBERS block

21 block 22 block 23 block 24 block block data carrier automotive system 110 internai combustion engine engine block cylinder cylinder head camshaft 140 piston crankshaft combustion chamber cam phaser fuel injector 170 fuel rail fuel pump fuel source intake manifold 205 air intake pipe 210 intake port 215 valves 220 port 225 exhaust manifold 230 turbocharger 240 compressor 245 turbocharger shaft 250 turbine 260 intercooler 270 exhaust system 275 exhaust pipe 280 aftertreatment devices 281 lean NOx trap 282 selective catalytic reduction (SCR) system 283 selective catalytic reduction systems comprising a particulate filters (SCRF) 284 NH3INOx dua' sensor upstream the SCRISCRF 285 NH3/NOx dual sensor downstream the SCR/SCRF 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 temperature and level sensors 385 lubricating oil temperature and level sensor 390 metal temperature sensor 400 fuel rail pressure sensor 410 cam position sensor 420 crank position sensor 430 exhaust pressure and temperature sensors 440 EGR temperature sensor 445 accelerator position sensor 446 accelerator pedal I fl Aff(1 rt-I I i_U tUU CL'U

Claims (14)

1. CLAIMS1. Method of optimizing ammonia generation in an exhaust system (270) of an internal combustion engine (110) of an automotive system (100), the exhaust system comprising at least two after-treatment devices (280), the after-treatment devices being at least a lean NOx trap (281) and a selective catalytic reduction system (282) or a selective catalytic reduction system comprising a particulate filter (283), the method comprising: -predicting or measuring (20) the present ammonia production from said lean NOx trap (281) during its regeneration phase under rich combustion conditions, -comparing (21) said present ammonia production with an optimal ammonia production needed by the selective catalytic reduction system (282, 283) and in case the present ammonia production is higher or lower than the optimal ammonia production, -acting (22) on at least one parameter (23, 24, 25), influencing said lean NOx trap regeneration phase, to reach the optimal ammonia production.
2. 2. Method according to claim 1, wherein said parameter is one of the possible end criteria (23) of the lean NOx trap regeneration phase.
3. 3. Method according to claim 2, wherein if the present ammonia production is lower than the optimal ammonia production, the end criteria (23) of the lean NOx trap regeneration phase are modified by increasing the time of the regeneration phase under rich combustion conditions.
4. 4. Method according to claim 2, wherein if the present ammonia production is higher than the optimal ammonia production, the end criteria (23) of the lean NOx trap regeneration phase are modified by interrupting the regeneration phase under rich combustion conditions.
5. 5. Method according to claim 1, wherein said parameter is a target value of the ratio air/fuel (24).
6. 6. Method according to claim 5, wherein if the present ammonia production is lower than the optimal ammonia production, the target value of the ratio air/fuel (24) is reduced.
7. 7. Method according to claim 5, wherein if the present ammonia production is higher than the optimal ammonia production, the target value of the ratio air/fuel (24) is increased, by interrupting the regeneration phase under rich combustion conditions.
8. 8. Method according to claim 1, wherein said parameter is one of the possible criteria (25)10 activate the lean NOx trap regeneration phase.
9. 9. Method according to claim 8, wherein possible criteria to activate the lean NOx trap regeneration phase are temperature, NOx engine-out amount, NOx stored amount and/or space velocity.
10. 10. Internal combustion engine (110) of an automotive system (100) equipped with an exhaust system (270), comprising at least two after-treatment devices (280), the after-treatment devices being at least a lean NOx trap (281) and a selective catalytic reduction system (282) or a selective catalytic reduction system comprising a particulate filter (253), the automotive system (100) comprising an electronic control unit (450) configured for carrying out the method according to claims 1-9.
11. 11. A computer program comprising a computer-code suitable for performing the method according to any of the claims 1-9.
12. 12. Computer program product on which the computer program according to claim 11 is stored.
13. 13. Control apparatus for an internal combustion engine, comprising an Electronic Control Unit (450), a data carrier (40) associated to the Electronic Control Unit (450) and a computer program according to claim 11 stored in the data carrier (40).
14. 14. An electromagnetic signal modulated as a carrier for a sequence of data bits representing the computer program according to claim 11.