Title of Invention

METHOD FOR OPERATING A MULTI-CYLINDER INTERNAL COMBUSTION ENGINE

Abstract The invention relates to a method for operating a multi-cylinder internal combustion engine, especially a direct injection internal combustion engine. According to the invention, fuel is injected into a combustion chamber via a high- pressure injection valve in a first operational mode during a compression phase and in a second operational mode during an induction phase. In addition, the engine is switched over between the operated modes, and the torques of the individual cylinders of the internal combustion engine are equated, whereby the cylinder equalization is effected in the first operational mode by means of a controller. In order to be able to effect the cylinder equalization in a simple, quick and effective manner and while using few calculations, the invention provides that the injection correction factors for correcting cylinder-specific torque errors in a number of operating points are determined and stored, statistical flow rate errors and dynamic flow rate errors of the high-pressure injection valve are determined, and the quantity of fuel to be injected into the combustion chamber is corrected for according to the determined flow rate errors of the high-pressure injection valve.
Full Text

Method for operating a multicylinder internal combustion engine
Prior art
The present invention relates to a method for operating a multicylinder internal combustion engine, in particular a direct-injection internal combustion engine, in which fuel is injected into a combustion chamber via a high-pressure injection valve during a compression phase in a first operating mode and during an induction phase in a second operating mode, and in which a change is made between the operating modes and the torques of the individual cylinders in the internal combustion engine are balanced, with the cylinder balancing being carried out in the first operating mode by means of a regulator. The present invention also relates to an internal combustion engine, in particular a direct-injection internal combustion engine, having a combustion chamber into which fuel can be inj ected via a high-pressure injection valve during a compression phase in a first operating mode and during an induction phase in a second operating mode, having a controller for switching between the operating modes, and having a regulator for cylinder balancing at least in the first operating mode. Finally, the present invention also relates to a controller for such an internal combustion engine.
Such systems for direct injection of fuel into the combusti on chamber of an internal combustion engine are generally known. In this case, a distinction is drawn between what is referred to as stratified operation as the first operating mode, and what is referred to as homogeneous operation as the second operating mode.

stratified operation is used in particular ar relatively low loads, while homogeneous operation is used for relatively high loads applied to the internal combustion engine.
During stratified operation, the fuel is injected into the combustion chamber during the compression phase of the internal combustion engine, in such a manner that a fuel cloud is located in the immediate vicinity of a spark plug at the time of ignition. This injection can be carried out in a different way. For example, it is possible for the injected fuel cloud to be located close to the spark plug even during the injection process, or immediately after it, and to be ignited by this spark plug. It is likewise possible for the injected fuel cloud to be passed through a charging movement to the spark plug, and only then to be ignited. The fuel is not distributed uniformly, b.ut in the form of stratified charge, in both combustion processes .
The advantage of stratified operation is that the internal combustion engine can match the relatively small loads applied with only a very small amount of fuel. However, the larger loads cannot be coped with by
means of stratified operation.
In the homogeneous operation which is intended for such relatively large loads, the fuel is injected during the induction phase of the internal combustion engine, so that vortex formation, and hence distribution of the fuel in the combustion chamber, can still take place directly. To this extent, homogeneous operation corresponds approximately to the method operation of internal combustion engines in which fuel is injected into the induction manifold in the normal manner. If required, homogeneous operation can also be used for relatively low loads.

During stratified operation, the throttle valve in the induction manifold leading to the combustion chamber is opened wide, and the combustion process is controlled and/or regulated essentially only by the amount of fuel to be injected. During homogeneous operation, the throttle valve is opened or closed as a function of the required torque, and the amount of fuel to be injected is controlled and/or regulated as a function of the amount of air induced.
In both operating modes, that is to say during stratified operation and during homogeneous operation, the mass of fuel to be injected is also controlled and/or regulated as a function of a number of other operating variables to a value which is optimum with regard to fuel saving, exhaust gas reduction and the like. The control and/or regulation are/is carried out by the controller for the internal combustion engine and differ/differs in the two operating modes.
In direct-injection internal combustion engines, the fuel is generally injected into the combustion chambers of the internal combustion engine via high-pressure injection valves. Owing to manufacturing tolerances and the result of wear, the high-pressure injection valves have a different opening pressure. However, since the same injection pressure is applied to the high-pressure injection valves via a common high-pressure reservoir, different amounts of fuel are injected into the individual combustion chambers which can lead to rough running cf the internal combustion engine, to increased exhaust gas emissions and to increased fuel consumption.
In order to compensate for the effects of production and wear-dependent changes in the flow characteristic through the high-pressure injection valves used for

fuel injection, means for cylinder balancing in a multicylinder internal combustion engine are known from DE 198 28 279. In this case, the torques produced by the individual cylinders in the internal combustion engine are balanced by varying the amount of fuel to be injected into the combustion chamber. A torque output from the individual cylinders that is as uniform as possible has a positive effect on stable running, emissions and the consumption of internal combustion engine.
DE 198 28 279 Al proposes that each cylinder have a pilot control characteristic map, which is determined adaptively during operation of the internal combustion engine. During stratified operation, cylinder balancing is carried out by means of a regulator, in which case the pilot control characteristic map can be used to reduce the load on the regulator for cylinder balancing and for dynamic response improvement. During homogeneous operation, an injection correction factor, which is determined from the pilot control characteristic map is used to correct the inj ection time. During homogeneous operation, the output variable from the regulator is constant over time, that is to say the regulator is inactive, and cylinder balancing is carried out with the control loop open.
However, in DE 198 2 8 27 9 Al, the open-loop cylinder balancing during homogeneous operation is carried out considering only the steady-state flow quantity error, that is to say only long injaction times are evaluated. The dynamiic flow quantity errors are ignored. Although this allows the torque errors from the individual cylinders to be corrected when the injection times are long, that is to say when the internal combustion engine needs to produce a large torque and is being operated on load. It is, however, not possible to compensate sufficiently for the torque errors when the

injection . times are short, for example when the
internal combustion engine is idling, leading to the
internal combustion engine running roughly and not
uniformly.
The object of the present invention is to improve the cylinder balancing such that it can correct the torque errors from the individual cylinders for both long and short injection times and both in the first operating mode and in the second operating mode of the internal combustion engine.
In order to achieve this object, the invention proposes, against the background of the method of the type mentioned initially, that
- injection correction factors required to correct for torque errors from the individual cylinders are determined at a number of operating points and are stored,
- steady-state flow quantity errors and dynamic flow quantity errors are determined for the high-pressure inj ection valve from the injection correction factors, and
- the amount of fuel to be injected into the combustion chamber is corrected as a function of the determined flow quantity errors for the high-pressure injection valve.
Advantages of the invention
Thus, according to the invention, the injection correction factors for the individual cylinders of the internal combustion engine are first of all detected at a number of operating points. An operating point is defined, inter alia, by the amount of mixture and the mixture composition of the cylinder filling. Once the injection correction factors have been detected, they are stored.

Torque errors from the individual cylinders are caused predominantly by errors, in particular flow quantity errors, between the high-pressure injection valves. The flow quantity errors thus reflect the torque errors from the cylinders relatively accurately. The present invention makes use of this relationship and uses the stored injection correction factors "during normal operating of the internal combustion engine to determine the flow quantity errors of the high-pressure injection valves during stratified operation and/or during homogeneous operation- The amount of fuel to be injected into the combustion chamber is then corrected as a function of the determined flow quantity errors of the high-pressure injection valve, for torque matching for the individual cylinders .
The steady-state error is defined as the flow quantity error that occurs in the steady state when the high-pressure injection valve is fully open. The dynamic error is defined as the flow quantity error occurring in the steady state plus the error, which occurs dynamically when the high-pressure injection valve is being opened and closed. The dynamic flow quantity error of the high-pressure injection valve, in particular, has a critical influence on the amount of fuel injected into the combustion chamber of a cylinder via the high-pressure injection valve, and thus on the torque produced by that cylinder.
Due to the fact that, according to the invention, not only the steady-state but also the dynamic flow quantity errors of the high-pressure injection valves in the internal combustion engine are determined from the stored injection correction factors and are included in the correction of the amount of fuel to be injected into the combustion chamber, steady and uniform running of the internal combustion engine can

be ensured at every internal combustion engine operating point, both during stratified operation and during homogeneous operation.
One advantageous development of the present invention proposes that the injection correction factors be detected exclusively in the first operating mode, that is to say during stratified operation. During stratified operation, the torque errors -of the individual cylinders are compensated for completely by means of the cylinder balancing regulator. The amount of fuel is proportional to the torque produced by the internal combustion engine. The regulator action by the regulator corresponds to the injection correction factor. During stratified operation, the injection correction factors can thus be detected particularly accurately, and torque differences between the individual cylinders in the internal combustion engine are completely eliminated.
An alternative development of the present invention proposes that the injection correction factors of the individual cylinders be detected both in the first operating mode and in the second operating mode, that
is to say during homogeneous operation. In contrast to the situation during stratified operation, the control system does not carry out cylinder balancing during homogeneous operation, so that there is no assurance that the fuel and torque are proportional. However, an adaptive method can be used to reduce the torque errors in relatively large steps, preferably to zero. The injection correction factor required for this purpose is detected. The use of the adaptive method, which in each case corrects only the two cylinders which differ to the greatest extent, allows the torque differences, and hence the fuel differences, to be reduced.

The injection correction factors determined during homogeneous operation admittedly result in less accuracy than the injection correction factors determined during stratified operation, but the reliability is in this case better owing to the lambda=l combustion, particularly as the components of the internal combustion engine become older.
However, if a cylinder-specific lambda value is available, the torque errors during homogeneous operation can also be compensated for by means of the regulator. In contrast to the situation during stratified operation, the relationship between the amount of fuel and the torque produced by the internal combustion engine is, however, not linear.
One preferred embodiment of the present invention proposes that common steady-state and dynamic flow quantity errors be determined from the injection correction factors detected in the first operating mode and from the injection correction factors detected in the second operating mode, and that these be used as the basis for correcting the amount of fuel to be injected into the combustion chamber. The common flow quantity errors can be determined from the injection correction factors by any desired operations. Averaging, weighting and filtering of the injection correction factors should be mentioned here, by way of example -
The injection correction factors can be processed in any desired way in order to determine the common flow quantity errors. Thus, for example, a common steady-state flow quantity error can be determined from the steady-state flow quantity errors determined during stratified operation and during homogeneous operation, In the same way, a common dynamic flow quantity error can be determined from the dynamic flow quantity errors

determined during stratified operation and during homogeneous operation. Alternatively, both the steady-state and dynamic flow quantity errors can be used when determining the common steady-state and dynamic flow quantity error,
A further option for forming the common flow quantity errors is to use steady-state and dynamic flow quantity errors determined during stratified operation as common flow quantity errors, provided the flow quantity errors determined during stratified operation and during homogeneous operation match, to a first approximation. If, however, the flow quantity errors determined during stratified operation and during homogeneous operation do not match, the steady-state and dynamic flow quantity errors determined during homogeneous operation are used as the common flow quantity errors. This admittedly leads to the torque errors of the individual cylinders in the internal combustion engine probably not being corrected completely, but they are more reliable than the flow quantity errors determined during stratified operation, and are therefore preferable.
Another advantageous development of the present invention proposes that the regulator actions required by the regulator to correct for the torque errors from the individual cylinders be used as injection correction factors for cylinder balancing. The injection correction factors are thus determined and stored in a manner known per se from DE 198 28 279 Al. In this context, reference is expressly made to DE 198 28 279 Al,
One preferred embodiment of the present invention proposes that the injection time of the high-pressure injection valves be varied in order to correct the amount of fuel to be injected into the combustion

chamber. The amount of fuel to be injected via the corresponding high-pressure injection valve is then corrected using the two correction variables determined for each cylinder in the internal combustion engine -the steady-state and the dynamic flow quantity errors. Each injection time is varied multiplicatively with the steady-state flow quantity error, and additively with the dynamic flow quantity error.
The determined injection correction factors for cylinder balancing are advantageously stored in characteristic map. The characteristic map can preferably be stored in the controller for the internal combustion engine. The characteristic map covers firstly the rotation speed of the internal combustion engine and secondly the torque emitted from the internal combustion engine. During operation of the internal combustion engine, the controller can then access the stored injection correction factors, determine the corresponding flow quantity errors of the high-pressure injection valve, and appropriately correct the amount of fuel to be injected into the combustion chamber.
One preferred embodiment of the present invention proposes that, if the injection times are long, the injection correction factor corresponding to the operation point be used as the steady-state flow quantity error. If the injection times are relatively long, the injection correction factor provides a reliable value for the steady-state flow quantity error, since the influence of the dynamic error, that is to say the error resulting from the process of opening and closing the high-pressure injection valve, becomes less as the injection times become longer.
A further preferred embodiment of the present invention likewise proposes that, if the injection times are

short, the injection correction factor corresponding to the operating point be used as the dynamic flow quantity error. The shorter the injection times are, that is to say the shorter the time period in which the high-pressure injection valve is opened or closed, the greater is the influence of the dynamic error on the flow quantity error of the high-pressure injection valve .
The present invention allows the manufacturing tolerances of high-pressure injection valves to be widened. This can be done since the behavior of each individual high-pressure injection valve is detected on a cylinder-specific basis, and is taken into account for cylinder balancing. Furthermore, according to the invention, the dynamic flow quantity errors of the high-pressure injection valves are also taken into account for cylinder balancing, thus allowing complete correction for the torque errors from the individual cylinders, especially when the injection times are short.
The implementation of the method according to the invention in the form of a control element which is provided for a controller for an internal combustion engine, in particular for a direct-injection internal combustion engine, is particularly important. In this case, the control element is used to store a programme which can run on a computation device, in particular on a microprocessor, in the controller, and which is suitable for carrying out the method according to the invention. Thus, in this case, the invention is implemented by a programme stored in the control element, so that this control element, provided with the programme, represents the invention in the same way as the method for whose implementation the programme is suitable. An electrical storage medium can be used, in

particular, as the control element, for example a read only memory (ROM) or a flash memory.
As a further solution for the object of the present invention, and based on the internal combustion engine of the type mentioned initially, it is proposed that, in the controller
- injection correction factors required to correct for torque errors from the individual cylinders determine at a number of operating points and store,
- a steady-state flow quantity error and a dynamic flow quantity error are determined for the high-pressure injection valve from the injection correction factors, and
- the amount of fuel to be injected into the combustion chamber is corrected as a function of the determined flow quantity errors for the high-pressure injection valve.
Finally, as a solution to the object of the present invention and based on the controller for an internal combustion engine of the type mentioned initially, it is proposed that, in the controller
- injection correction factors required to correct for torque errors from the individual cylinders determine at a number of operating points and store,
- a steady-state flow quantity error and a dynamic flow quantity error are determined for the high-pressure injection valve from the injection correction factors, and
- the amount of fuel to be injected into the combustion chamber is corrected as a function of the determined flow quantity errors for the high-pressure injection valve.
The regulator actions of a regulator for cylinder balancing are preferably used as injection correction factors.

Drawings
One preferred exemplary embodiment of the present
invention will be explained in more detail in the
following text with reference to the drawings, in
which:
Figure 1 shows a schematic block diagram of one
preferred embodiment of an internal combustion engine according to the invention;
Figure 2 shows a further schematic block diagram of
the internal combustion engine shown in Figure 1; and
Figure 3 shows one preferred embodiment of a
controller according to the invention.
Description of the exemplary embodiments
Figure 1 shows a direct-injection internal combustion engine 1 for a motor vehicle, in which a piston 2 can move in a reciprocating manner in a cylinder 3. The
internal combustion engine 1 has z cylinders 3. The cylinders 3 are each provided with a combustion chamber 4 which is bounded, inter alia, by the piston 2, an inlet valve 5 and an outlet valve 6. An induction manifold 7 is coupled to the inlet valve 5, and an exhaust manifold 8 is coupled to the outlet valve 6.
A high-pressure injection valve 9 and a spark plug 10 project into the combustion chamber 4 in the area of the inlet valve 5 and of the outlet valve 6. Fuel can be inject-ed into the combustion chamber 4 via the high-pressure injection valve 9. The fuel in the combustion chamber 4 can be ignited by the spark plug 10. In a first operating mode (stratified operation),

the fuel is injected into the combustion chamber 4 during a compression phase, and in a second operating mode (homogeneous operation) , it is injected into the combustion chamber 4 during an induction phase. It is possible to switch between the two operating modes during operation of the internal combustion engine 1.
The combustion of the fuel in the combustion chamber 4 causes the piston 2 to carry out a reciprocating movement, which is transmitted to a crankshaft 11 (see Figure 2) and exerts a torque Milk on this crankshaft 11,
An encoder wheel 12 is arranged on the crankshaft 11, and its rotation angle is detected by means of a sensor 13. A further sensor 14 is arranged on the cylinder 3 and detects, for example, the top dead center position of the piston 2 as the boundary between two operating cycles of a four-stroke internal combustion engine. The signals from the sensors 13 and 14 are transmitted to a controller 15, which generates an injection pulse signal tic for actuating the high-pressure injection valve 9 in a cylinder i (i = 1 . . , z) at the operating point k for the internal combustion engine 1. An operating point k is defined, inter alia, by the amount of mixture and the mixture composition for cylinder filling.
A detail of the controller 15 is illustrated in Figure 3. The controller 15 generates, in a manner known per se from DE 198 28 279 Al, injection correction factors rich for each cylinder i in the internal combustion engine 1, by means of suitable regulators Rim (1=1 ... z), for example PI regulators. In this context, reference is made expressly to DE 198 28 279 Al , The signals from the sensors 13, 14 for the cylinder i are passed to the regulator R i.

The injection correction factors r_ik are the factors required for correction of the torque errors M_f_ik from the individual cylinders i in the internal combustion engine 1. The determined injection correction factors r_ik are stored in a cylinder-specific characteristic map K_(i = 1 .>, 2) as a function of the operating point. The rotation speed n_k and the torque M_k of the internal combustion engine 1 are passed to the characteristic maps K_i in order to determine the operating point k.
The injection correction factors _kin for the individual cylinders i are detected both during stratified operation and during homogeneous operation, During stratified operation, the torque errors M__f__ik from the individual cylinders i are compensated for completely by means of a regulator R_i. The amount of fuel is thus proportional to the torque M_k produced by the internal combustion engine 1, The regulator actions of the regulator R__i correspond to the injection correction factor r_ik. During stratified operation, the injection correction factors can thus be detected particularly accurately, and torque differences between the individual cylinders i in the internal combustion engine 1 are completely eliminated.
In contrast to the situation during stratified operation, the control system does not operate during homogeneous operation, so that no proportionality is ensured between the fuel and the torque M_k. However, an adaptive method can be used which reduces the torque errors M_f_ik in relatively large steps, preferably to zero. The injection correction factor r_ik required for this purpose is detected. The injection correction factors determined during homogeneous operation

are admittedly less accurate, but they are more reliable owing to the lambda - 1 combustion,
However, if a cylinder-specific lambda value is available, the torque errors M_f_ik even in homogeneous operation can be compensated for by means of the regulator R_i down to a lambda value of approximately 0.85. In contrast to the situation during stratified operation, the relationship between the amount of fuel and the torque M_k produced by the internal combustion engine 1 is, however, nonlinear.
Steady-state flow quantity errors q_stat and dynamic flow quantity errors q__dyn are then determined in a function block 17 from the injection correction factors r__ik. During stratified operation of the internal combustion engine 1, the injection correction factors r_ik generated by the regulators R_i are used to determine the flow quantity errors q_stat, q_dyn. During homogenous operation of the internal combustion engine 1, the injection correction factors r__ik for the respective operating point k are taken from the characteristic map K_i. Switches 18 are used to switch between stratified operation ("S" position) and homogeneous operation ("H" position) . The switches 18 are operated via an operating unit 19 in the controller 15. The operating unit 19 determines the present operating mode of the internal combustion engine 1 as a function of various characteristic operating variables 20 of the internal combustion engine 1.
According to' the invention, if the injection times t_ik are long, the injection correction factor r_ik corresponding to the operating point k is used as the steady-state flow quantity errors q_stat in the function block 17, since the influence of the dynamic flow quantity errors q_dyn becomes less the longer the injection time t ik is, that is to say the longer the

time period is during which the high-pressure injection valve 9 is opened or closed. If the injection times t_ik are short, the correction factor q_dyn which corresponds to the operating point k is used as the dynamic flow quantity error q_dyn, since the influence of the steady-state flow quantity error q_stat becomes less the shorter the injection times t_ik are, that, is to say the shorter the time period is during which the high-pressure injection valve 9 is operated.
The injection correction factors ^_ik for the individual cylinders i are then used in a processing unit 21 in the controller 15 to determine the corrected injection time t_ik for a specific cylinder i at a specific operating point k. To be more precise, the steady-state flow quantity error q_stat is used to multiplicatively correct each calculated injection time, and the dynamic flow quantity error q__dyn is used to additively correct each injection time. Furthermore, the processing unit 21 can also be used to carry out filtering or normalization of the determined injection times t_ik.
Thus, in summary, the injection correction factors t__ik
are determined first of all. During stratified operation and during homogeneous operation down to lambda = 0.85, the torque errors M__f_ik are reduced to zero by means of the regulator R_i. The regulator actions of the regulator R__i correspond to the injection correction factors r_ik. During stratified operation, there is a proportional relationship between the amount "of fuel and the torque M_k that is produced, while the relationship is non-linear during homogeneous operation down to lambda = 0.85. The injection correction factors r_ik are stored in cylinder-specific characteristic maps K i in the controller 15,

During operation of the internal combustion ' engine 1, the injection correction factors ^__ik stored for a specific operating point k in the characteristic maps K_i are used to determine steady-state and dynamic flow quantity errors q_stat, q_dyn. The amount of fuel to be injected into the combustion chambers 4 is corrected as a function of the flow quantity errors q_stat, q_dyn, so that each cylinder i produces the same torque M_ik irrespective of the magnitude of the error from the individual high-pressure injection valves 9. This has a positive effect on smooth running, emissions and the consumption of the internal combustion engine 1.
The present invention allows the manufacturing tolerances of high-pressure injection valves 9 to be widened. This is possible since the dynamic flow quantity errors q_dyn are also taken into account in the correction of the torque errors M_f_ik, and because the behavior of each individual high-pressure injection valve 9 in the internal combustion engine 1 is detected on a cylinder-specific basis, and is taken into account for cylinder balancing.




Claims
1. Meth'
comb'
Injection internal combustion engine, in which fuel is injected into a combustion chamber (4) via a high-pressure injection valve (9) during a compression phase in a first operating mode and during an induction phase in a second operating mode, and in which a change is made between the operating modes and the torques of the individual cylinders in the internal combustion engine are balanced, with the cylinder balancing being carried out in the first operating mode by means of a regulator, characterized in that
- Injection correction factors (r__ik) required to
correct for torque errors (M f ik) from the
individual cylinders (i) are determined at a number of operating points (k) and are stored,
- steady-state flow quantity errors (q stat) and
dynamic flow quantity errors (q dyn) are
determined for the high-pressure injection valve (9) from the injection correction factors (r_ik), and
the amount of fuel to be injected into the combustion chamber (4) is corrected as a function of the determined flow quantity errors
(q_stat, q_dyn) for the high-pressure injection valve (9).
2. Method according to Claim 1, characterized in that
the injection correction factors (r_ ik) are
detected only during the first operating mode.

3. Method according to Claim 1, characterized in that
the injection correction factors (r ik) are
detected both in the first operating mode and in the second operating mode.
4. Method according to Claim 3^ characterized in that
common steady-state and dynamic flow quantity
errors (q stat, q dyn) are determined from the
injection correction factors (r ik) detected in
the first operating mode and from the injection
correction factors (r ik) detected in the second
operating mode, and this is used as the basis for correcting the amount of fuel to be injected into the combustion chamber (4).
5. Method according to one of Claims 1 to 4, characterized in that the regulator actions required by the regulator to correct for the torque errors (M_f__ik) of the individual cylinders (i) are used as injection correction factors (r_ik) for cylinder balancing.
6. Method according to one of Claims 1 to 5, characterized in that the injection time is varied in order to correct the amount of fuel to be injected into the combustion chamber (4).
7. Method according to one of Claims 1 to 6, characterized in that the injection correction factors (r_ik) are stored in characteristic map (K_i).
8 . Method according to one of Claims 1 to 1, characterized in that, for long injection times, the
injection correction factor (r ik) corresponding
to the operating point (k) is used as the steady-state flow quantity error (q_stat).

9. Method according to one of Claims 1 to 8, charac
terized in that, for short injection times, the
injection correction factor (r ik) corresponding
to the operating point (k) is used as the dynamic flow quantity error (q_dyn).
10. Control element, in particular a read only memory
(ROM) or flash-Memory, for a controller (15) for an internal combustion engine (1), in particular a direct-injection internal combustion engine, in which a programme is stored which can run on a computation device, in particular on a microprocessor, in the controller (15), and is suitable for carrying out a method according to one of the preceding claims.
11. Internal combustion engine (1), in particular a
direct-injection internal combustion engine,
having a combustion chamber (4) into which fuel
can be injected via a high-pressure injection
valve (9) during a compression phase in a -first
operating mode and during an induction phase in a
second operating mode, having a controller (15)
for switching between the operating modes, and
having a regulator for cylinder balancing at least
in the first operating mode, characterized in
that, in the controller (15)
- injection correction factors (r__ik) required to
correct for torque errors (M f ik) from the
individual cylinders (i) are determined at a number of operating points (k) and are stored,
- A steady-state flow quantity error (q_stat) and
a dynamic flow quantity error (q dyn) are
determined for the high-pressure injection valve
(9) from the injection correction factors (r_ik), and
the amount of fuel to be injected into the combustion chamber (4) is corrected as a f
of the determined flow quantity errors (q_stat, q_dyn) for the high-pressure injection valve (9).
12. Controller (15) for an internal combustion engine (1), in particular a direct-injection internal combustion engine, which has a combustion chamber (4) into which fuel can be -^injected via a high-pressure injection valve (9) during a compression phase in a first operating mode and during an induction phase in a second operating mode, and having a regulator for cylinder balancing at least in the first operating mode, with the controller (15) being provided for switching between the operating modes, characterized in that, in the controller (15)
- injection correction factors (r_ik) required to
correct for torque errors (M f ik) from the
individual cylinders (i) determined at a number of operating points (k) and are stored,
- A steady-state flow quantity error (q_stat) and
a dynamic flow quantity error (q dyn) are
determined for the high-pressure injection valve (9) from the injection correction factors (r_ik)f and
the amount of fuel to be injected into the combustion chamber (4) is corrected as a function of the determined flow quantity errors
(q_stat, q_dyn) for the high-pressure in action valve (9),

Method for operating a multicylinder internal combustion engine, substantially as hereinabove described and illustrated with reference to the accompanying drawings.


Documents:


Patent Number 208671
Indian Patent Application Number IN/PCT/2001/1546/CHE
PG Journal Number 35/2007
Publication Date 31-Aug-2007
Grant Date 07-Aug-2007
Date of Filing 07-Nov-2001
Name of Patentee m/s. ROBERT BOSCH GMBH
Applicant Address Postfach 30 02 20, 70442 Stuttgart
Inventors:
# Inventor's Name Inventor's Address
1 KLENK, Martin Stresemannstrasse 11, 71522 Backnang
2 UHL, Stephan Saint-DiƩ-Strasse 14, 88045 Friedrichshafen
PCT International Classification Number F02D 41/34
PCT International Application Number PCT/DE01/00346
PCT International Filing date 2001-01-30
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 100 12 025.3 2000-03-11 Germany