PILOT CONTROL OF AN INTERNAL COMBUSTION ENGINE

Abstract

A method, computer program product and apparatus for the pilot control of a mixture preparation for an internal combustion engine are disclosed, which include determining a configuration of the internal combustion engine. The configuration is determined by a combination of discrete positions of a plurality of actuators which influence at least one operating parameter of the internal combustion engine. The method, computer program product and apparatus additionally determine a constant adaptation component of the mixture preparation which is fed back by an exhaust gas probe of the internal combustion engine, and store the constant adaptation component and the associated configuration in memory. The pilot control of the mixture preparation is performed with the constant adaptation component when the internal combustion engine is operated in the same configuration.

Claims

1. A method for the pilot control of a mixture preparation for an internal combustion engine, wherein the method comprises: determining a configuration of the internal combustion engine, wherein the configuration is realized by a combination of discrete positions of a plurality of actuators which influence at least one operating parameter of the internal combustion engine; determining a constant adaptation component of the mixture preparation which is fed back by an exhaust gas probe of the internal combustion engine; storing the constant adaptation component and the associated configuration; and performing pilot control of the mixture preparation with the constant adaptation component when the internal combustion engine is operated in the same configuration.

2. The method as claimed in claim 1, wherein a large number of configurations with associated constant adaptation components are used.

3. The method as claimed in claim 2, wherein an associated constant adaptation component is used for each combination of discrete positions of the actuators.

4. The method as claimed in claim 1, wherein the mixture preparation relates to a quantity of fuel to be injected into a combustion chamber of the internal combustion engine.

5. The method as claimed in claim 1, wherein the pilot control operation performed takes into account the constant adaptation component in an additive manner.

6. The method as claimed in claim 1, wherein the pilot control operation performed takes into account the constant adaptation component in a multiplicative manner.

7. The method as claimed in claim 1, wherein the mixture preparation is performed depending on at least one operating parameter of the internal combustion engine, and a way in which the constant adaptation component is taken into account during the pilot control operation is dependent on the at least one operating parameter.

8. The method as claimed in claim 7, wherein the mixture preparation is performed depending on a plurality of operating parameters of the internal combustion engine and respectively associated constant adaptation components are used for different ratios of the plurality of operating parameters.

9. A computer program product for pilot control of a mixture preparation for an internal combustion engine, the computer program product stored in non-transitory memory such that when executed by a processing device, the computer program product causes the processing device to: determine a configuration of the internal combustion engine, wherein the configuration is realized by a combination of discrete positions of a plurality of actuators which influence operating parameters of the internal combustion engine; determine a constant adaptation component of the mixture preparation which is fed back by an exhaust gas probe of the internal combustion engine; store, in the non-transitory memory, the constant adaptation component and the associated configuration; and perform pilot control of the mixture preparation with the constant adaptation component when the internal combustion engine is operated in the same configuration.

10. The computer program product of claim 9, wherein the computer program product determines a constant adaptation component of the mixture preparation for each of a plurality of configurations of the internal combustion engine.

11. The computer program product of claim 9, wherein an associated constant adaptation component is used for each combination of discrete positions of the actuators.

12. The computer program product of claim 9, wherein the mixture preparation relates to a quantity of fuel to be injected into a combustion chamber of the internal combustion engine.

13. The computer program product of claim 9, wherein the pilot control operation takes into account the constant adaptation component in an additive manner or an multiplicative manner.

14. The computer program product of claim 9, wherein the mixture preparation is performed depending on at least one operating parameter of the internal combustion engine, and a way in which the constant adaptation component is taken into account during the pilot control operation is dependent on the at least one operating parameter.

15. The computer program product of claim 9, wherein the mixture preparation is performed depending on the operating parameters of the internal combustion engine and respectively associated constant adaptation components are used for different ratios of the plurality of parameters.

16. An apparatus for the pilot control of a mixture preparation for an internal combustion engine, wherein the apparatus comprises: a first interface configured to sample a configuration of the internal combustion engine, wherein the configuration is realized by a combination of discrete positions of a plurality of actuators which influence operating parameters of the internal combustion engine; a second interface configured to sample a constant adaptation component of a mixture preparation which is fed back by an exhaust gas probe of the internal combustion engine; a memory configured to record the constant adaptation component and the associated configuration; and- a processing device, coupled to the memory, configured to provide the constant adaptation component to the mixture preparation when the internal combustion engine is operated in the same configuration.

17. The apparatus of claim 16, wherein the pilot control takes into account the constant adaptation component in an additive manner or a multiplicative manner.

18. The apparatus of claim 16, wherein the mixture preparation is performed depending on at least one operating parameter of the internal combustion engine, and a way in which the constant adaptation component is taken into account during the pilot control operation is dependent on the at least one operating parameter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The embodiments of the invention will now be described in more detail with reference to the appended figures, in which:

[0023] FIG. 1 shows an internal combustion engine with a mixture preparation; and

[0024] FIG. 2 shows phase spaces of the mixture preparation of FIG. 1.

DETAILED DESCRIPTION

[0025] FIG. 1 shows an internal combustion engine 100 with a mixture preparation 105. The internal combustion engine 100 may be designed, in particular, for operation in a motor vehicle. The internal combustion engine 100 may include a multi-cylinder reciprocating-piston engine. The mixture preparation 105 is connected to a number of sensors 125 and actuators 130. The mixture preparation 105 determines the quantity of fuel which should be injected into the internal combustion engine 100 for combustion. In one embodiment, the mixture preparation 105 is designed to drive a fuel injector 135 for dispensing the determined quantity of fuel. The quantity of fuel is usually determined with respect to one or more parameters which may be tapped off from the internal combustion engine 100. For example, one of the sensors 125 may be an airflow meter, a rotation speed sensor or a torque sensor. Further sensors are likewise possible and may determine, for example, different temperatures or pressures in the internal combustion engine 100.

[0026] The operation of the internal combustion engine 100 may additionally be influenced by means of at least one actuator 130, wherein the actuator 130 has a fixedly predetermined number of discrete positions. A plurality of actuators 130 are usually provided, the actuators controlling, for example, a stroke or a phase of an inlet valve, a stroke or a phase of an outlet valve, a compression of a cylinder or the use of one or more possible injectors.

[0027] The mixture preparation 105 is connected to a processing device 155 by means of an interface 150, the processing device in turn being connected to a memory 160. The processing device 155 is configured to determine, during conventional operation in which a λ probe 140 is available, a deviation between a quantity of fuel which is determined on the basis of the sensors 125 and positions of the actuators 130, and the quantity of fuel which is determined on the basis of the signal from the λ probe 140. In particular, a constant proportion is determined and stored in the memory 160 from this difference. This value is associated with a configuration of the internal combustion engine 100, which configuration is dependent on assumed discrete positions of the actuators 130 owing to the combination. In other words, a pair of values may be formed, which pair of values comprises the combination and the constant adaptation component used. In another embodiment, a fixed location in the memory 160 is associated with one combination and the determined constant adaptation component is stored at the associated point.

[0028] If the internal combustion engine 100 is operated at a later time without the λ probe 140 being available, for example because it does not yet output a useful signal during a warm-running phase of the internal combustion engine 100, the mixture preparation 105 has to control the internal combustion engine 100 or determine the quantity of fuel to be injected in the pilot control mode, that is to say without feedback by the signal of the λ probe 140. To this end, it is proposed to obtain, via the interface 150, that constant adaptation component which corresponds to the current configuration of the internal combustion engine 100 from the memory 160 using the processing device 155. This adaptation component is then used to correct the quantity of fuel which was determined on the basis of the positions of the actuators 130 and the signal values from the sensors 125.

[0029] A direct relationship between the mixture adaptation and the actuators 130 which are involved in the deviation may be expressed by the constant adaptation component. Temperature dependences of an actuator 130 and of the drive strategy of the actuator 130 may be automatically taken into account since the drive strategy is reflected in the configuration of the internal combustion engine 100. If, for example, a piston stroke of the internal combustion engine 100 is first changed over at a predetermined operating temperature, this changeover is also automatically taken into account in the pilot control mode by the proposed procedure. Adaptations to the actuators 130 which can adapt the drive strategy, for example by means of influences such as aging of an actuator 130, may automatically also influence the position of the mixture adaptation range. Different configurations of the internal combustion engine 100 at the same operating point in respect of rotation speed, load and temperature of the internal combustion engine 100 may also have different adaptation values in this way.

[0030] FIG. 2 shows phase spaces 200 of the mixture preparation 105 of FIG. 1. A load L of the internal combustion engine 100 is plotted in the horizontal direction, and the rotation speed N of said internal combustion engine is plotted in the vertical direction. Different configurations K of the internal combustion engine 100 are indicated along a third axis.

[0031] At least one constant adaptation component, which is used for determining the quantity of fuel to be injected, is prespecified for each configuration K. In the illustration of FIG. 2, two adaptation values, which cover different parts of the respective phase space, are prespecified for each configuration K. Purely by way of example, the phase spaces are separated into subspaces 205 which have a substantially triangular shape.

[0032] The associated constant adaptation components may be taken into account in an additive manner or in a multiplicative manner in different embodiments. In one embodiment, the way in which the adaptation components are taken into account may be dependent on the load of the internal combustion engine 100. In this case, the transfer may be made in discrete steps or continuously. For example, the stored constant adaptation component may be taken into account in an additive manner in the case of a low load, while the adaptation component is taken into account in a multiplicative manner in the case of a higher load. For a continuous transfer, the processes of taking into account the adaptation component both in an additive manner and in a multiplicative manner are determined and weighted by means of weighting factors which are dependent on the load. The sum of the weighted correction terms is then passed on to the processing device 105.

[0033] As in the case of a known mixture adaptation, the correction of the fuel pilot control may be taken into account directly during calculation of the quantity of fuel to be injected. However, ascertaining the correction value to be taken into account depends, amongst other things, on the currently active logical engine:

MFF_SP_COR=MFF_SP_BAS*[Σ(AD_i_LogEng_k×FAC_i_k)]/Σ(FAC_i_k)]*FAC_LAM* . . .

[0034] where:

[0035] MFF_SP_COR: actuating value for fuel flow, which actuating value is corrected by exhaust gas control

[0036] MFF_SP_BAS: actuating value for basic fuel flow

[0037] LogEng_k: logical engine k

[0038] AD_i_LogEng_k: adaptation value i of the logical engine k

[0039] FAC_i_k: weighting factor for adaptation value i of the logical engine k

[0040] FAC_LAM: correction of the lambda pilot control and/or lambda control.

[0041] When a changeover is made between actuator positions, the transition between two related adaptation values is also defined by means of the weighting factors FAC_i_k. This transition represents the physical transition in this case. A transition may therefore be performed in a synchronized manner at the moment at which, for example, a valve stroke is changed in order to apply the correct adaptation value in good time for the purpose of calculating the associated injection mass. Furthermore, a transition may, however, also be performed with a time delay or in the form of a smoothed transfer.

[0042] Embodiments have been described herein in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the invention are possible in light of the above teachings. The description above is merely exemplary in nature and, thus, variations may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.

LIST OF REFERENCE SYMBOLS

[0043] 100 Internal combustion engine [0044] 105 Mixture preparation [0045] 110 Processing device [0046] 125 Sensor [0047] 130 Actuator [0048] 135 Fuel injector [0049] 140 Lambda probe [0050] 150 Interface [0051] 155 Processing device [0052] 160 Memory [0053] 200 Phase space [0054] 205 Subspace [0055] L Load [0056] N Rotation speed [0057] K Configurations