DE202014009562U1 - Determining the amount of post-injection fuel in an internal combustion engine - Google Patents

Abstract

An internal combustion engine (110) comprising a fuel injector (160) for injecting fuel into a combustion chamber (150) of the engine, a catalyst (281, 282) disposed in an exhaust conduit (275), and an electronic controller (450) adapted therefor To: determine a temperature value of the catalyst (281, 282); To determine an amount of fuel based on the determined temperature value; and - actuating the fuel injector (160) to inject the determined amount of fuel through a post-injection.

Description

TECHNICAL AREA

This invention relates to an internal combustion engine. In particular, the present invention relates to an internal combustion engine, a motor vehicle system, a control device and a method for determining an amount of fuel to be injected by means of a post-injection in the internal combustion engine. This determination can be used to carry out a regeneration of the diesel particulate filter.

BACKGROUND

Modern diesel engines are provided with a particulate filter (eg, a diesel particulate filter, DPF) incorporated into their exhaust aftertreatment system and designed to trap the soot (carbon and other particulates) in the exhaust to meet applicable emission limits.

Electronic control units for controlling the internal combustion engine can detect when the particulate filter is full of soot, and arrange a so-called DPF regeneration process, d. H. a process in which the particulate filter is emptied by burning away the soot accumulated therein.

DPF regeneration is usually accomplished by raising the exhaust gas temperature to a temperature setpoint (eg, 600-640 ° C) for a short period of time (about 10 minutes). To achieve this temperature setpoint, so-called late fuel injections are usually performed in the DPF regeneration process.

In the late fuel injections, small amounts of fuel are injected into the combustion chamber of the internal combustion engine after the piston has passed top dead center (OTP).

The late injections may include secondary injections that actually burn in the combustion chamber and post-injections that are performed after the exhaust valve is opened, exit the combustion chamber unburned, and represent a real contribution to the HC content of the exhaust gas.

The hydrocarbons (HC) present in the exhaust gases burn in catalysts (such as in a diesel oxidation catalyst or a NOx trap for lean operation, which are also referred to in the present specification with DOC and LNT), which may be arranged in the exhaust pipe , typically upstream of the DPF, so that these DOC and / or LNT become a type of heat generator.

The amount of fuel to be injected by the post-injections is usually referred to as the sum of a closed-loop contribution (also referred to herein as a closed-loop contribution) and an open-loop contribution (in the present specification Also known as OL contribution - from the English "open loop contribution").

The CL contribution is determined as a function of an error between a measured value and a target value of the temperature at the DPF inlet.

The OL contribution is usually determined based on engine operating point (i.e., engine speed and engine load).

This means that there are usually specific calibration maps in the electronic control unit that relate each engine operating point (i.e., each pair of engine speed and engine load) to a corresponding value of the OL contribution to the fuel to be injected by the post-injections.

These calibration maps are usually determined on a test bench, taking into account the temperatures that the catalysts and particulate traps reach while the engine is operating in a steady state.

Under real driving conditions, d. H. however, as the automotive system progresses, environmental conditions and transient operating conditions may have a significant effect on the temperature of the catalytic converter and the particulate filter, which at a given engine operating point may differ from the temperatures measured during calibration of the maps.

Due to this deviation, the OL contribution to the fuel quantity of the post-injections may be so incorrect that it is no longer possible with the CL contribution to compensate for the error effectively, whereby the efficiency of the regeneration process is reduced and / or the DPF thermal load is suspended.

An object of the present invention is to provide a solution which remedies the above defects and therefore is able to protect the DPF in a regeneration operation during normal driving operation and to increase the efficiency of the DPF regeneration process.

These and other objects are achieved by the embodiments of the invention having the features described in the independent claims. The dependent claims describe preferred and / or particularly advantageous aspects.

SUMMARY

• – einen Temperaturwert des Katalysators zu bestimmen;
• – eine Kraftstoffmenge auf Basis des bestimmten Temperaturwerts zu bestimmen; und
• – den Kraftstoffinjektor zu betätigen, um die bestimmte Kraftstoffmenge durch eine Nacheinspritzung einzuspritzen.

One embodiment of the disclosure provides an internal combustion engine comprising a fuel injector for injecting fuel into a combustion chamber of the engine, a catalyst disposed in an exhaust conduit, and an electronic control device configured to:

• To determine a temperature value of the catalyst;
• To determine an amount of fuel based on the determined temperature value; and
• - To operate the fuel injector to inject the specific amount of fuel through a post-injection.

Thanks to this solution, an accurate determination of the amount of fuel to be injected by post-injections can be achieved, taking into account the temperatures that the catalyst achieves when the engine is operated under real driving conditions, thereby lowering the thermal load on the DPF during a regeneration process and increasing the Efficiency of the regeneration process can be achieved.

In one aspect of the invention, the catalyst may be an oxidation catalyst (i.e., a diesel oxidation catalyst, DOC) and / or a lean NOx trap (LNT).

• – Bestimmen eines ersten im offenen Regelkreis ermittelten Beitrags zur Kraftstoffmenge auf Basis eines Motorbetriebspunkts,
• – Bestimmen eines zweiten im offenen Regelkreis ermittelten Beitrags zur Kraftstoffmenge auf Basis des bestimmten Temperaturwerts des Oxidationskatalysators,
• – Addieren des ersten und des zweiten im offenen Regelkreis ermittelten Beitrags.

According to another aspect of the invention, the electronic control unit may be configured to determine the amount of fuel by the following steps:

• Determining a first open-loop fuel quantity based on an engine operating point,
• Determining a second open-loop fuel quantity determination based on the determined temperature value of the oxidation catalyst,
• - Adding the first and the second determined in the open loop contribution.

In this way, the determination of the amount of fuel to be injected by the post-injections can be rational and simple, since the first open-loop contribution is pre-calibrated (for example, on a bench, taking into account the temperatures reached by the catalysts and particulate traps during the run) Internal combustion engine operating in a stationary state) and then, if necessary, during normal driving operation can be corrected by adding the second open-loop determined contribution, which takes into account the temperatures that the catalysts actually reach during normal driving.

According to one embodiment of the invention, the electronic control unit may be configured to determine the second open loop determined contribution based on a difference between the determined temperature value of the catalyst and a reference value.

For example, the reference value may be determined based on an engine operating point.

In this way, an exact determination or correction of the amount of fuel to be injected by the fuel injector by means of post-injections can be performed by the electronic control unit.

Alternatively or additionally, the reference value may be determined based on an ambient pressure and an ambient temperature, i. H. based on the environmental conditions under which the combustion engine operates.

Thanks to this solution, the electronic control unit can perform a more accurate determination or correction of the amount of fuel to be injected by the fuel injector by means of the post-injections, taking into account the influence of ambient conditions on the exhaust gas temperature.

According to one aspect of the invention, the electronic control unit may be configured to set the second open-loop contribution to zero for multiple engine operating points.

In this way it is possible to carry out a correction of the first contribution determined in the open control loop only if this is necessary, ie. H. when specific regeneration conditions occur during the real driving operation of the internal combustion engine, for example, when the internal combustion engine is idling or in an off state.

• – Bestimmen eines im geschlossenen Regelkreis ermittelten Beitrags zur Kraftstoffmenge auf Basis einer Differenz zwischen einem gemessenen Wert und einem Zielwert einer Temperatur eines in der Abgasleitung angeordneten Partikelfilters,
• – Addieren des im geschlossenen Regelkreis ermittelten Beitrags zum ersten und zum zweiten im offenen Regelkreis ermittelten Beitrag.

According to another aspect of the invention, the electronic control unit may be configured to determine the amount of fuel by the following further steps:

• Determining a contribution to the fuel quantity determined in a closed loop on the basis of a difference between a measured value and a target value of a temperature of a particle filter arranged in the exhaust gas line,
• Adding the contribution determined in the closed loop to the first and second contributions determined in the open loop.

In this way, the closed loop feedback can effectively compensate for the residual temperature error between steady state engine operation and real driving conditions, thereby increasing the efficiency of the regeneration process and / or lowering the thermal load on the DPF.

Another embodiment of the invention provides a motor vehicle system, in particular a passenger car, comprising an internal combustion engine as described above.

• – Bestimmen eines Temperaturwerts des Katalysators;
• – Bestimmen einer Kraftstoffmenge auf Basis des bestimmten Temperaturwerts; und
• – Betätigen des Kraftstoffinjektors, um die bestimmte Kraftstoffmenge durch eine Nacheinspritzung einzuspritzen.

Another embodiment of the invention provides a method for determining an amount of fuel to be injected into the internal combustion engine by post-injection, the internal combustion engine comprising a fuel injector for injecting fuel into a combustion chamber of the engine and a catalyst disposed in an exhaust conduit, the method comprising following steps include:

• Determining a temperature value of the catalyst;
• Determining a fuel quantity based on the determined temperature value; and
• Actuate the fuel injector to inject the determined amount of fuel through a post-injection.

Thanks to this solution, an accurate determination of the amount of fuel to be injected by post-injections can be achieved, taking into account the temperatures that the catalyst achieves when the engine is operated under real driving conditions, thereby lowering the thermal load on the DPF during a regeneration process and increasing the Efficiency of the regeneration process can be achieved.

In one aspect of the invention, the catalyst may be an oxidation catalyst (i.e., a diesel oxidation catalyst, DOC) and / or a lean NOx trap (LNT).

• – Bestimmen eines ersten im offenen Regelkreis ermittelten Beitrags zur Kraftstoffmenge auf Basis eines Motorbetriebspunkts,
• – Bestimmen eines zweiten im offenen Regelkreis ermittelten Beitrags zur Kraftstoffmenge auf Basis des bestimmten Temperaturwerts des Oxidationskatalysators,
• – Addieren des ersten und des zweiten im offenen Regelkreis ermittelten Beitrags.

According to another aspect of the invention, the step of determining the amount of fuel may include the steps of:

• Determining a first open-loop fuel quantity based on an engine operating point,
• Determining a second open-loop fuel quantity determination based on the determined temperature value of the oxidation catalyst,
• - Adding the first and the second determined in the open loop contribution.

In this way, the determination of the amount of fuel to be injected by the post-injections can be rational and simple, since the first open-loop contribution is pre-calibrated (for example, on a bench, taking into account the temperatures reached by the catalysts and particulate traps during the run) Internal combustion engine operating in a stationary state) and then, if necessary, during normal driving operation can be corrected by adding the second open-loop determined contribution, which takes into account the temperatures that the catalysts actually reach during normal driving.

• – Bestimmen des zweiten im offenen Regelkreis ermittelten Beitrags auf Basis einer Differenz zwischen dem bestimmten Temperaturwert des Katalysators und einem Referenzwert.

According to one embodiment of the invention, the method may comprise the following steps:

• Determining the second contribution determined in the open control loop on the basis of a difference between the determined temperature value of the catalytic converter and a reference value.

For example, the reference value may be determined based on an engine operating point.

In this way, an exact determination or correction of the fuel quantity to be injected by the fuel injector by means of post-injections can be performed by the electronic control unit.

Alternatively or additionally, the reference value may be determined based on an ambient pressure and an ambient temperature, i. H. based on the environmental conditions under which the combustion engine operates.

Thanks to this solution, the electronic control unit can perform a more accurate determination or correction of the amount of fuel to be injected by the fuel injector by means of the post-injections, taking into account the influence of ambient conditions on the exhaust gas temperature.

According to an aspect of the invention, the method may include the step of zeroing the second open-loop contribution to a plurality of engine operating points.

In this way it is possible to carry out a correction of the first open-loop determined contribution only when necessary, ie when specific regeneration conditions occur during the real driving operation of the internal combustion engine, for example when the internal combustion engine is idling or in an off state is.

• – Bestimmen eines im geschlossenen Regelkreis ermittelten Beitrags zur Kraftstoffmenge auf Basis einer Differenz zwischen einem gemessenen Wert und einem Zielwert einer Temperatur eines in der Abgasleitung angeordneten Partikelfilters,
• – Addieren des im geschlossenen Regelkreis ermittelten Beitrags zum ersten und zum zweiten im offenen Regelkreis ermittelten Beitrag.

According to another aspect of the invention, the step of determining the amount of fuel may include the steps of:

• Determining a contribution to the fuel quantity determined in a closed loop on the basis of a difference between a measured value and a target value of a temperature of a particle filter arranged in the exhaust gas line,
• Adding the contribution determined in the closed loop to the first and second contributions determined in the open loop.

In this way, the closed loop feedback can effectively compensate for the residual temperature error between steady state engine operation and real driving conditions, thereby increasing the efficiency of the regeneration process and / or lowering the thermal load on the DPF.

• – Mittel zum Bestimmen eines Temperaturwerts des Katalysators;
• – Mittel zum Bestimmen einer Kraftstoffmenge auf Basis des bestimmten Temperaturwerts; und
• – Mittel zum Betätigen des Kraftstoffinjektors, um die bestimmte Kraftstoffmenge durch eine Nacheinspritzung einzuspritzen.

Another embodiment of the invention provides a controller for determining an amount of fuel to inject into the internal combustion engine by means of a post-injection, the internal combustion engine comprising a fuel injector for injecting fuel into a combustion chamber of the engine and a catalyst disposed in an exhaust conduit, the controller comprising includes:

• - means for determining a temperature value of the catalyst;
• - means for determining an amount of fuel based on the determined temperature value; and
• - means for actuating the fuel injector to inject the determined amount of fuel through a post-injection.

Thanks to this solution, an accurate determination of the amount of fuel to be injected by post-injections can be achieved, taking into account the temperatures that the catalyst achieves when operating the engine under real driving conditions, thereby lowering the thermal load on the DPF during a regeneration process and increasing the fuel flow Efficiency of the regeneration process can be achieved.

In one aspect of the invention, the catalyst may be an oxidation catalyst (i.e., a diesel oxidation catalyst, DOC) and / or a lean NOx trap (LNT).

• – Mittel zum Bestimmen eines ersten im offenen Regelkreis ermittelten Beitrags zur Kraftstoffmenge auf Basis eines Motorbetriebspunkts,
• – Mittel zum Bestimmen eines zweiten im offenen Regelkreis ermittelten Beitrags zur Kraftstoffmenge auf Basis des bestimmten Temperaturwerts des Oxidationskatalysators,
• – Mittel zum Addieren des ersten und des zweiten im offenen Regelkreis ermittelten Beitrags.

According to another aspect of the invention, the means for determining the amount of fuel may include:

• Means for determining a first open loop fuel quantity estimate based on an engine operating point,
• Means for determining a second open-loop contribution to fuel quantity based on the determined temperature value of the oxidation catalyst,
• - means for adding the first and the second open loop determined contribution.

In this way, the determination of the amount of fuel to be injected by the post-injections can be rational and simple, since the first open-loop contribution is pre-calibrated (for example, on a bench, taking into account the temperatures reached by the catalysts and particulate traps during the run) Internal combustion engine operating in a stationary state) and then, if necessary, during normal driving operation can be corrected by adding the second open-loop determined contribution, which takes into account the temperatures that the catalysts actually reach during normal driving.

• – Mittel zum Bestimmen des zweiten im offenen Regelkreis ermittelten Beitrags auf Basis einer Differenz zwischen dem bestimmten Temperaturwert des Katalysators und einem Referenzwert.

According to one embodiment of the invention, the controller may include:

• - means for determining the second contribution determined in the open loop on the basis of a difference between the determined temperature value of the catalyst and a reference value.

For example, the reference value may be determined based on an engine operating point.

In this way, an exact determination or correction of the fuel quantity to be injected by the fuel injector by means of post-injections can be performed by the electronic control unit.

Alternatively or additionally, the reference value may be determined based on an ambient pressure and an ambient temperature, i. H. based on the environmental conditions under which the combustion engine operates.

Thanks to this solution, the electronic control unit can perform a more accurate determination or correction of the amount of fuel to be injected by the fuel injector by means of the post-injections, taking into account the influence of ambient conditions on the exhaust gas temperature.

According to one aspect of the invention, the controller may include means for zeroing the second open loop contribution to a plurality of engine operating points.

In this way it is possible to carry out a correction of the first contribution determined in the open control loop only if this is necessary, ie. H. when specific regeneration conditions occur during the real driving operation of the internal combustion engine, for example, when the internal combustion engine is idling or in an off state.

• – Mittel zum Bestimmen eines im geschlossenen Regelkreis ermittelten Beitrags zur Kraftstoffmenge auf Basis einer Differenz zwischen einem gemessenen Wert und einem Zielwert einer Temperatur eines in der Abgasleitung angeordneten Partikelfilters,
• – Mittel zum Addieren des im geschlossenen Regelkreis ermittelten Beitrags zum ersten und zum zweiten im offenen Regelkreis ermittelten Beitrag.

According to another aspect of the invention, the means for determining the amount of fuel may include:

• Means for determining a contribution to the fuel quantity determined in the closed-loop control on the basis of a difference between a measured value and a target value of a temperature of a particle filter arranged in the exhaust gas conduit,
• - means for adding the contribution determined in the closed-loop control to the first and second open-loop contributions.

In this way, the closed loop feedback can effectively compensate for the residual temperature error between steady state engine operation and real driving conditions, thereby increasing the efficiency of the regeneration process and / or lowering the thermal load on the DPF.

BRIEF DESCRIPTION OF THE DRAWINGS

Now, the various embodiments will be described by way of example with reference to the accompanying drawings, in which:

1 shows a motor vehicle system;

2 a cross-section of a to the motor vehicle system of 1 belonging internal combustion engine;

3 FIG. 4 is a block diagram of an engine and exhaust after-treatment system according to one embodiment of the invention; FIG.

4 FIG. 3 is a flow chart of a method performed according to one embodiment of the invention. FIG.

DETAILED DESCRIPTION OF THE DRAWINGS

Some embodiments may be a motor vehicle system 100 include that in the 1 and 2 is shown and that an internal combustion engine (ICE) 110 with an engine block 120 owns at least one cylinder 125 with a piston 140 defined, which has a coupling with which the crankshaft 145 is turned. A cylinder head 130 works with the piston 140 together to a combustion chamber 150 define. An air-fuel mixture (not shown) enters the combustion chamber 150 introduced and ignited, resulting in hot expanding combustion gases, leading to a reciprocation of the piston 140 to lead. The fuel is from at least one fuel injector 160 provided and the air through at least one inlet 210 , The fuel is under high pressure from a fuel pipe 170 , the fluid zueitend with a high-pressure pump 180 that the pressure of a fuel source 190 increased fuel, is connected to the fuel injector 160 guided.

Each of the cylinders 125 has at least two valves 215 coming from a camshaft 135 operated at the same time as the crankshaft 145 rotates. The valves 215 selectively release air from the inlet 210 in the combustion chamber 150 and alternately allow the outlet of the exhaust gases through the outlet 220 , In some examples, a camshaft phasing system 155 used to selectively the timing between the camshaft 135 and the crankshaft 145 to change.

The air can be the air inlets 210 via an intake manifold 200 be supplied. An air inlet pipe 205 leads the intake manifold 200 Ambient air too. In other embodiments, a throttle 330 be selected to control the air flow to the intake manifold 200 to regulate. In other embodiments, a compressed air system such as a turbocharger is used 230 with a compressor 240 that is together with a turbine 250 turns, used. The rotation of the compressor 240 increases the pressure and the temperature of the air in the pipe 205 and the intake manifold 200 , One in the lead 205 containing intercooler 260 can reduce the temperature of the air. The turbine 250 turns when flowing from an exhaust manifold 225 coming exhaust gases, the exhaust gas from the outlet 220 passes through a series of vanes before passing through the turbine 250 is expanded. The exhaust gases leave the turbine 250 and become an exhaust aftertreatment system 270 guided. This example shows a variable geometry turbine (VGT) 250 with a VGT actuator 290 configured to move the vanes to cause the vanes to alter the flow of exhaust gas through the turbine. In other embodiments, the turbocharger may have a fixed geometry and a wastegate. The exhaust aftertreatment system 270 can a exhaust pipe 275 comprising one or more exhaust aftertreatment devices 280 having.

The also in 3 illustrated exhaust pipe 275 can be an exhaust pipe 276 with one or more of said exhaust aftertreatment devices 280 exhibit. exhaust aftertreatment devices 280 may be any devices with which the composition of the exhaust gases can be changed. Some examples of exhaust aftertreatment devices 280 are catalytic (two- and three-way) converters, for example an oxidation catalyst (ie diesel oxidation catalyst DOC 281 ) and a NOx trap for lean operation (LNT 282 ). Other examples of aftertreatment devices 280 include a particulate filter (ie, a diesel particulate filter DPF 283 as described above) and Selective Catalytic Reduction (SCR) systems. Other embodiments include an exhaust gas recirculation (EGR) system. 300 that with the exhaust manifold 225 and the intake manifold 200 connected is. The EGR system 300 can be an EGR cooler 310 exhibit the temperature of the exhaust gases in the EGR system 300 to reduce. An EGR valve 320 regulates the flow of exhaust gases in the EGR system 300 ,

In the present example, the DOC is 281 in the exhaust pipe 275 along the exhaust pipe 276 upstream of the DPF 283 arranged. The DOC 281 usually comprises a catalyst substrate, which may be a body (brick) of ceramic or metal with a honeycomb structure, the purpose of which is to provide a large surface area. The catalyst substrate is provided with a coating which acts as a support for the catalytic materials and serves to distribute these materials over a large surface area. The coating can be made by various technologies and materials, such as. Example, alumina, titania, silica or a mixture of silica and alumina. The coating materials are selected to form a rough, irregular surface which greatly increases the area compared to the smooth surface of the bare substrate. This maximizes the catalytically active area available for reaction with the exhaust gas. The DOC 281 further comprises a mixture of platinum group materials (PGM), which constitute the catalytic materials dispersed in the coating. The PGM mixture is suspended in the coating before the coating is applied to the catalyst substrate. The PGM mixture usually comprises palladium (Pd), which increases the thermal stability of the catalyst, thereby reducing its wear due to aging effects, and platinum (Pt), which is mainly used as the oxidation catalyst.

The DOC 281 is mainly designed to oxidise hydrocarbons (HC) and carbon monoxide (CO) into carbon dioxide (CO ₂ ) and water. In other words, the catalyst substrate (ie, the material of which it is made, its dimensions, volume, etc.) as well as the coating (ie, the material of which it is made, production technology, etc.) and the PGM mixture (ie, materials, Quantities, etc.) of the DOC 281 chosen such that substantially the above-mentioned effect is achieved, namely the oxidation of the hydrocarbons contained in the exhaust gases (KW) and the carbon monoxide contained therein (CO) in carbon dioxide (CO ₂ ) and water. In particular, the PGM mixture of the DOC 281 an amount of palladium (Pd) and an amount of platinum (Pt), wherein the ratio (Pt: Pd) of platinum to palladium (in terms of weight) is relatively low in order to increase the thermal stability and the wear of the DOC 281 due to aging. For example, the ratio Pt: Pd in the DOC 281 be equal to 1: 1. The catalyst substrate of the DOC 281 can be a metal. The coating of the DOC 281 may be a normal oxidation layer.

In the present example, the LNT 282 which captures the nitrogen oxides (NOx) contained in the exhaust gas, in the exhaust pipe 275 along the exhaust pipe 276 upstream of the DPF 283 and, for example, downstream from the DOC 281 arranged, the LNT 282 for example in the DOC 281 can be integrated and / or connected to it. Specifically, it is the LNT 282 to a catalytic device, the catalyst materials such. As rhodium, Pt and Pd and adsorbents such. B. barium-based substances that provide active sites that are suitable for binding the exhaust oxides contained in the exhaust gas (NOx), to catch them in the device itself.

In the in 3 example shown, the exhaust pipe 276 a variety of connecting pipes 277 . 278 . 279 comprising the aftertreatment devices 280 connect with each other. So connects a first connecting pipe 277 in particular the exhaust manifold 225 with an inlet of the DOC 281 , a second connecting pipe 278 may be an outlet of the DOC 281 with an inlet of the LNT 282 connect, and a third connecting pipe 279 connects an outlet of the LNT 282 with an inlet of the DPF 283 , The DPF 282 has an outlet tube that can release exhaust into the environment, or it can be connected to other components, such as a selective catalytic reduction (SCR) system, an exhaust damper (not shown), or other components.

The motor vehicle system 100 can still use an electronic control unit (ECM) 450 configured to receive signals from or to various, with the ICE 110 connected sensors and / or devices to send or receive. The ECM 450 It can receive input signals from various sensors designed to generate the signals proportional to various physical parameters associated with the ICE 110 are. The sensors include, but are not limited to, a mass flow, pressure, and temperature sensor 340 for the air, a pressure and temperature sensor 350 for the manifold, a sensor 360 for the pressure in the combustion chamber, sensors 380 for the coolant and oil temperature and / or the associated fill level, a pressure sensor 400 for the fuel, a camshaft position sensor 410 , a crankshaft position sensor 420 , Sensors 430 for the pressure and the temperature of the exhaust gases, an EGR temperature sensor 440 as well as a position sensor 445 for the gas pedal. Furthermore, the sensors can be a sensor 284 for the temperature of the DOC, for example, upstream of the DOC 281 on the first connecting pipe 277 is arranged.

Furthermore, the ECM 450 to output various signals to control the operation of the ICE 110 to control, for example, to fuel injectors 160 , to the throttle 330 , to the EGR valve 320 , to the wastegate actuator 290 and to the camshaft adjusting system 155 , It should be noted that dashed lines are used to indicate various connections between the various sensors, devices and the ECM 450 but others have been omitted for purposes of clarity.

The control unit 450 may have a digital microprocessor unit (CPU) data-connected to a memory system and a bus system. The CPU is adapted to execute instructions executed as a program stored in a memory system, to detect input signals from the data bus, and to output signals to the data bus. The storage system may have various storage media such as optical, magnetic, solid state and other non-volatile media. The data bus may be configured to send, receive, and modulate analog and / or digital signals to and from the various sensors and control devices. The program may be such that it is capable of embodying the methods described herein so that the CPU may perform the steps of such methods, and thus the ICE 110 can control. The stored program in the storage medium is the control unit from the outside wired or supplied by radio. Outside the vehicle system 100 it regularly appears on a computer program product, also referred to in the art as a computer or machine readable medium, which is to be understood as a computer program code on a carrier. The wearer may be volatile or non-volatile with the result that one can also speak of a volatile or non-volatile nature of the computer program product.

An example of a volatile computer program product is a signal, such as an electromagnetic signal, such as an optical signal, that is a transient carrier for the computer program code. The carrying of the computer program code can be achieved by modulating the signal with a conventional modulation technique such as QPSK for digital data, so that binary data representing the computer program code is impressed on the volatile electromagnetic signal. Such signals are used, for example, when a computer program code is wirelessly transmitted to a laptop over a WiFi connection.

In the case of a non-transitory computer program product, computer program code is embodied in a substrate-bound storage medium. The storage medium is then the non-volatile carrier referred to above, such that the computer program code is permanently or non-permanently stored in or on the storage medium in a retrievable manner. The storage medium may be of the conventional type known in the field of computer technology, for example a flash memory, an asic, a CD and the like.

Instead of an engine control unit 450 can the motor vehicle system 100 have a different type of processor to provide the electronic logic, such as an embedded controller, an on-board computer, or any other type of processor that can be used in a vehicle.

What the exhaust aftertreatment system 270 so concerns the ECM 450 z. B. during operation of the ICE 110 a regeneration of the DPF 283 carry out.

As described above, during operation of the ICE 110 Particles and other pollutants in the DPF 283 a regeneration is required if their amount exceeds a predetermined threshold.

In detail, the regeneration of the DPF 283 one from the ECM 450 controlled process in which the DPF 283 Trapped particles are burned away.

The regeneration of the DPF 283 is through the ECM 450 triggered the operating mode of the ICE 110 from a normal mode of operation to a regeneration mode, usually with the fuel injectors changing 160 By secondary injections and / or post-injections, a certain amount of fuel is commanded to the combustion chambers 150 inject. In this way, the exhaust gas temperature becomes upstream of the DPF 283 (and downstream from the DOC 281 ) is increased to a predetermined temperature set point which can be determined as a calibration parameter and stored in the memory system.

The determination of the amount of fuel by means of a post-injection into the ICE 110 is to be injected by the ECM 450 performed and controlled, as described below and in 4 is shown.

The ECM 450 determined (block 500 ) based on the current engine operating point, that is, the current values of the engine speed and the engine load, a first in the open loop determined contribution to the amount of fuel to be injected by the post-injection. In particular, the ECM 450 use a first specific calibration map stored in the storage system and correlating each engine operating point (ie, each pair of engine speed and engine load) with a corresponding value of a first open loop contribution to the fuel to be injected by the post-injections. This first specific calibration map can be calibrated on a bench during the ICE 110 operating in a steady state and under standard environmental conditions.

Now the ECM 450 determine a second contribution to the fuel quantity, which is to be injected by means of post injection, in the open control loop (block 501 ).

This second open loop contribution may be a positive or negative fuel amount added to the first open loop feedback to determine an open loop fuel quantity to be injected by post injection.

The second open-loop contribution may be based on a temperature value of the DOC 281 be determined.

For example, the temperature value of the DOC 281 through the DOC temperature sensor 284 be measured (block 502 ), which in this example at the entrance of the DOC 281 is arranged.

More precisely, the ECM 450 the measured temperature value of the DOC 281 with a predetermined reference value of the temperature of the DOC 281 compare (block 503 ) and the second open loop determined contribution based on the difference between the measured temperature value and the reference value.

The reference value of the DOC temperature may be determined based on the current engine operating point.

In particular, the ECM 450 use a second specific calibration map stored in the storage system. This second specific calibration map relates each engine operating point (ie each pair of engine speed and engine load) to a corresponding reference DOC temperature value. The second specific map can be calibrated on a test bench while the ICE 110 works in a stationary state.

In some embodiments, the reference value of the temperature of the DOC may also be determined based on the ambient pressure and the ambient temperature.

For example, the reference values provided by the second map can be multiplied by a correction contribution (block 505 ), which is determined based on the actual environmental conditions under which the ICE 110 is operated, ie based on the measured ambient pressure and the measured ambient temperature. Ambient pressure and ambient temperature may be determined by the mass flow, pressure and temperature sensor, for example 340 be measured for the air.

According to one aspect of the strategy, the ECM 450 be set to zero the second open-loop contribution for certain predetermined engine operating points (Block 506 ).

For this, the ECM 450 use another specific calibration map determined as a calibration parameter and stored in the memory system that relates multiple engine operating points (ie, multiple engine speed and load engine pairs) with a factor of zero and several other engine operating points with a non-zero factor. The factor determined by this map is then multiplied by the second contribution determined in the open loop.

For example, the factor may be non-zero (eg, a factor equal to 1 or equal to another Value that is not zero) associated with one or more engine operating points that are an idle state of the ICE 110 Show.

Additionally or alternatively, the non-zero factor (eg, a factor equal to 1 or equal to a non-zero value) may be associated with one or more engine operating points that are a shutdown state of the ICE 110 indicate, in particular a shutdown state of the ICE 110 (For example, during a stop-start sailing operation of the ICE 110 ) occurring after an engine operating point that has a high engine load and / or a high engine speed of the ICE 110 displays.

The ECM 450 It may also be designed to calculate the total quantity determined in the open loop (ie the sum of the open loop contributions) of the fuel delivered by the fuel injector 160 injecting by post-injection is to be determined by means of a closed-loop control method (block 507 ).

In particular, the ECM 450 be designed to determine a contribution determined in the closed loop (which may be a positive or a negative value) of the fuel quantity corresponding to the fuel quantity determined in the open loop (eg the sum of the first and the second in the open loop) Loop determined contribution) is added.

The closed loop fuel amount contribution may be based on a difference between a measured value of the DPF temperature measured by, for example, a DPF temperature sensor or in a manner known to those skilled in the art, and a target temperature of the DPF 282 determined as a calibration parameter and stored in the memory system.

The ECM 450 It may be designed to add the contribution determined in the closed loop to the first and second open-loop contributions.

In particular, the ECM 450 as part of the closed-loop control method, a cyclic measurement of the temperature value of the DPF 283 with the DPF temperature sensor to detect an error (ie a difference) between the measured temperature value of the DPF 283 and the target value, and then use this error as input to a controller, for example a proportional-integral-derivative (PID) controller designed to match the open-loop contribution (the first and second) set in the open loop) is adjusted so that the calculated error is minimized.

In the foregoing summary and detailed description, at least one exemplary embodiment has been presented; however, it should be noted that there are a large number of modification options. It should also be noted that the exemplary embodiment or exemplary embodiments are only examples and are not intended to limit the scope, applicability, or construction in any way whatsoever. Rather, the foregoing summary and detailed description will provide those skilled in the art with a practical guide to implementing at least one example embodiment, it being understood that various changes may be made in the functions and arrangements of the elements described with reference to an exemplary embodiment without departing from the spirit of the invention Scope of protection as defined in the appended claims and their legal equivalents.

LIST OF REFERENCE NUMBERS

100

Automotive system

110

internal combustion engine

120

block

125

cylinder

130

cylinder head

135

camshaft

140

piston

145

crankshaft

150

combustion chamber

155

Cam Phaser System

160

fuel injector

165

Fuel injection system

170

Fuel pipe

180

Fuel pump

190

Fuel source

200

intake manifold

205

Air inlet line

210

inlet

215

valves

220

outlet

225

exhaust manifold

230

turbocharger

240

compressor

245

turbocharger shaft

250

turbine

260

Intercooler

270

aftertreatment system

275

exhaust pipe

276

exhaust pipe

277

first connecting pipe

278

second connecting pipe

279

third connecting pipe

280

aftertreatment devices

281

DOC

282

LNT

283

DPF

284

DOC temperature sensor

290

VGT

300

Exhaust gas recirculation system (EGR)

310

EGR cooler

320

EGR valve

330

throttle

340

Mass flow, pressure and temperature sensor for the air

350

Sensor for manifold pressure and temperature

360

Combustion pressure sensor

380

Sensors for coolant temperature and the associated level

385

Sensors for oil temperature and the associated level

390

Metal temperature sensor

400

digital fuel rail pressure sensor

410

Camshaft position sensor

420

Crankshaft position sensor

430

Sensors for pressure and temperature of the exhaust gases

440

EGR temperature sensor

445

Accelerator position sensor

446

accelerator

450

electronic control unit (ECM) / controller

500

block

501

block

502

block

503

block

504

block

505

block

506

block

507

block

Claims (10)

Internal combustion engine ( 110 ) comprising a fuel injector ( 160 ) for injecting fuel into a combustion chamber ( 150 ) of the engine, one in an exhaust pipe ( 275 ) arranged catalyst ( 281 . 282 ) and an electronic control unit ( 450 ) designed to: - a temperature value of the catalyst ( 281 . 282 ) to determine; To determine an amount of fuel based on the determined temperature value; and - the fuel injector ( 160 ) to inject the determined amount of fuel through a post-injection. Internal combustion engine ( 110 ) according to claim 1, wherein the catalyst comprises an oxidation catalyst ( 281 ). Internal combustion engine ( 110 ) according to one of the preceding claims, wherein the catalyst comprises a NOx trap for lean operation ( 282 ). Internal combustion engine ( 110 ) according to one of the preceding claims, wherein the electronic control unit ( 450 ) is arranged to determine the amount of fuel by the following steps: determining a first open loop fuel ratio based on an engine operating point, determining a second open loop fuel ratio based on the determined temperature value, adding the first and second contributions determined in the open loop. Internal combustion engine ( 110 ) according to claim 4, wherein the electronic control unit ( 450 ) is adapted to calculate the second open-loop contribution based on a difference between the determined temperature value of the catalyst ( 281 . 282 ) and a reference value. Internal combustion engine ( 110 ) according to claim 5, wherein the reference value is determined based on an engine operating point. Internal combustion engine ( 110 ) according to claim 5 or 6, wherein the reference value is determined based on an ambient pressure and an ambient temperature. Internal combustion engine ( 110 ) according to one of claims 4 to 7, wherein the electronic control unit ( 450 ) is configured to zero the second open loop estimated value for a plurality of predetermined engine operating points. Internal combustion engine ( 110 ) according to one of claims 4 to 8, wherein the electronic control unit ( 450 ) is adapted to determine the amount of fuel by the following further steps: - determining a contribution to fuel quantity determined in a closed loop on the basis of a difference between a measured value and a target value of a temperature in the exhaust pipe ( 275 ) arranged particulate filter ( 283 ), - Adding the contribution determined in the closed loop to the first and second open-loop contributions. Motor vehicle system ( 100 ) comprising an internal combustion engine ( 110 ) according to any one of the preceding claims.

Images