EP1597469A1

EP1597469A1 - Method, computer program and controller for operating an internal combustion engine

Info

Publication number: EP1597469A1
Application number: EP04712567A
Authority: EP
Inventors: Karin Kienle; Martin Lunt; Christian Tischer; Andreas Traub
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2003-02-21
Filing date: 2004-02-19
Publication date: 2005-11-23
Anticipated expiration: 2024-02-19
Also published as: JP4489754B2; KR20050103231A; DE10308459A1; US7337060B2; EP1597469B1; JP2006519951A; CN100400835C; US20070106452A1; CN1754039A; KR101033079B1; WO2004074665A1

Abstract

The invention relates to a method for controlling an internal combustion engine (20) of a certain model in accordance with a finite state machine (12). According to known methods, a possible operating state of the internal combustion engine is first adjusted which is associated with a level n of the finite state machine. In a further level (n+1), subordinate operating states relative to the operating state previously determined are specified by the known method. The aim of the invention is to streamline and simplify methods of the aforementioned type so that they can be adapted to control different models of internal combustion engines. For this purpose, the method and the finite state machine are designed in such a manner that the finite state machine comprises at least two groups of levels, the first group representing levels of operating states which the internal combustion engine of a certain model shares with internal combustion engines of a different model, and the second group of levels representing operating states which are specific for the internal combustion engine of a certain model.

Description

Method, computer program and control device for operating an internal combustion engine

State of the art

The invention relates to a method for operating an internal combustion engine of a certain type according to a state machine. The invention further relates to a computer program and a control device for performing this method.

State machines are generally known in the prior art and in particular in software development. Generally speaking, they depict different states of a system. The individual states of the system are represented by variables and the values assigned to them, which can be queried by software modules. State machines of this type, as shown in FIG. 4, are also known in principle for internal combustion engines; in this case, the state machines specify various possible operating states, represented by thick dots in FIG. 4, for operating the internal combustion engine of the specific type and allowable transitions between these operating states. The operating states in the state machines can be divided into several

Layers (l ... n, n + 1, ... N) can be grouped. The layers are structured hierarchically in such a way that at least one layer n is followed by at least one further layer n + 1, which comprises at least one sub-operating state for an operating state assigned to layer n.

Known state machines for internal combustion engines have gradually grown over time; they have been continually expanded to meet specific individual applications. This is the reason why existing state machines for internal combustion engines are very complex and bulky today. If known state machines for individual applications are to be used in connection with internal combustion engines of a certain type, it is inevitable today that with the implementation of the known state machines a large number of components or subsystems must also be installed that would not be absolutely necessary for the specific individual application.

Starting from this prior art, it is therefore the object of the invention to further develop the known method, computer program and control device described in such a way that simple and lean adaptation to different internal combustion engines of different types is possible.

This object is achieved by the method claimed in claim 1. Accordingly, to achieve this object, it is provided according to the invention that layer n and all layers upstream of it in the hierarchical structure of the state machine each represent operating states which the internal combustion engine of the specific type also has

Internal combustion engines of another type have in common and that the further layer as well as all layers downstream of it in the hierarchical structure of the state machine each represent operating states that are specific for the internal combustion engine of the specific type.

Advantages of different types of internal combustion engines are in particular diesel engines or gasoline engines.

As a result of the claimed division of the layers of the state machine according to the invention, when changing the type of internal combustion engine used, it is only necessary to replace or adapt those layers in the state machine that are specific to a particular internal combustion engine. All other layers of the state machine remain unaffected by the change. These other layers / parts of the software or the control of the internal combustion engine, which are only dependent on the general (reusable) layers of the state machine, can be used in various types of internal combustion engines without adaptation.

In other words, when changing the type of internal combustion engine used, it is no longer necessary to take over the entire state machine, which basically includes the operating states of a large number of internal combustion engines of different types. Rather, when using a new type of internal combustion engine, it is possible to use only those layers of the state machine which

Represent operating states that are cross-engine, that is, type-independent. From the other layers of the state machine then only those layers need to be taken over which are suitable for the specific internal combustion engine used. Individual, unneeded operating status modules can also be eliminated or exchanged within a selected further layer. Other layers that are basically available in the state machine can be omitted. In this way, a lean adaptation of the state machine to any application is possible.

According to a first exemplary embodiment of the invention, it is provided that the state machine for

Internal combustion engine has four layers. The first layer represents an operating state "motor control". As sub-modes to the operating state "driving motor"^', in the second layer, the operating states of "Start", "normal operation", and

"Follow-up" defined. The third layer in turn defines sub-operating states for the operating states of layer 3. It includes the states "standby", "ready", "start phase", "idle", "accelerate", "run down" and "end". Finally, the fourth layer includes the "pre-glow" or "not pre-glow" states as sub-operating states to the "ready" operating state in the third layer. It is important in this exemplary embodiment that the first to third layers represent operating states which are unspecific for the internal combustion engine of the specific type, and operating states are defined in the fourth layer which are specific for the internal combustion engine of the specific type. Further advantageous refinements of the method, wherein

the state machine is designed such that a transition between individual operating states represented by it is only possible under certain conditions are the subject of the subclaims. Furthermore, it is advantageous if the method is designed such that the state machine not only maps operating states of the internal combustion engine, but also various operating states of a control unit of the internal combustion engine.

The object of the invention is further achieved by a computer program for the control unit of the internal combustion engine and by the control unit itself. The advantages of these solutions to the problem correspond to the advantages described above with reference to the method according to the invention.

FIGURES The invention is described in detail below with reference to FIGS. 1-4 accompanying the description, wherein

1 shows the hierarchical basic structure of the state machine according to the invention;

Figure 2, which is shown by the state machine

Operating states of the internal combustion engine and the control device for the internal combustion engine; Figure 3 shows a control unit and an internal combustion engine; and

FIG. 4 general hierarchically structured layers of a state machine

shows.

Description of the embodiments

FIG. 1 shows an example of a basic structure of a state machine 12 for controlling an internal combustion engine of a certain type in accordance with the claimed method.

FIG. 3 shows such an internal combustion engine of a certain type 20, which is controlled via a control device 10 in accordance with the state machine 12 stored therein. A starter 15 controlled by the control unit 10 serves to start the internal combustion engine 20.

The basic structure 12 shown in FIG. 1 has a total of five layers n = 0 ... 4. An uppermost layer n = 0 represents the operating state "motor control". This is a superordinate term or state of all possible operating states of the internal combustion engine and the control unit. Only the various operating states of the internal combustion engine are discussed below; A discussion of the various operating states of the control unit follows below.

The top operating state in layer n = 1 is "Motor control" 1-6. In an underlying layer n = 2, various operating states of the internal combustion engine are summarized, which specify the higher-level operating state "motor control"; these are the operating states "Standby" 2-7 (optional), "Start" 2-8, "Normal operation" 2-9 and "Follow-up" 2-10. All the sub-operating states of the internal combustion engine, which serve to prepare the internal combustion engine for the start and to carry out the start, are summarized under the designation “start”. In these sub-operating conditions

are the states "Ready" 3-1 and "Start phase" 3-2, which are specified in a layer n = 3. Also in the third layer n = 3 are the sub-operating states "idle" 3-3 and "accelerating" 3-4 as sub-operating states for the higher-level state

"Normal operation" 2-9 described in the second layer n = 2. The third layer n = 3 comprises the states "start-up" 3-5 and "end" 3-6 as sub-operating states for the superordinate operating state "lag" 2-9 of the internal combustion engine, as it is called in the second layer. Finally, the state machine shown in FIG. 1 has a fourth layer n = 4, in which the state "ready" from the third layer n = 3 is specified in more detail by way of example. As an example, it can be checked during this "frosting" state in diesel engines whether a "preheating state" 4-1 or a "non-preheating" state 4-2 has been reached.

According to the invention, the first to third layers n = 1-3, insofar as they relate to the internal combustion engine and not to the control unit, only represent operating states which the internal combustion engine of a certain type, for example an Otto engine, with internal combustion engines of another type, for example with diesel engines , has in common. In contrast, the fourth layer mainly represents operating states that are specific to the internal combustion engine of certain types, diesel engines or Otto engines.

The individual previously mentioned operating states and the possible transitions between these operating states during the operation of the internal combustion engine are described in more detail below with reference to FIG. 2.

In the context of the state "motor control" 1-6, as can be seen from FIG. 2, the entire possible operation of the

Internal combustion engine of the certain type shown in summary. It is divided into the states "Standby" 2-7, "Start" 2-8, "Normal operation" 2-9 and "Follow-up" 2-10. The "standby" state 2-7 is designed as an energy-saving mode in which certain electrically operated auxiliary units of the internal combustion engine can be switched off. In the concept of an energy-saving mode, communication in the "standby" state is possible via a network with other control devices. In addition, during this state, for example, the operating temperature of the internal combustion engine can be monitored, the fuel supply to the internal combustion engine can be advanced, the throttle valve spring can be monitored or the emergency shutdown can be tested.

If the ignition of the vehicle or the internal combustion engine is switched on or other equivalent information is given to the control unit during the "standby" state 2-7, the "standby" state is exited and the control of the internal combustion engine changes to a "tire" -State 3-1; the engine 20 can then be started immediately. In the "tire" state, for example, power consumers can also be monitored; in the case of diesel engines, the preheating process could take place in the "tire" state according to an underlying layer n = 4. However, as soon as the starter 15 for the internal combustion engine is activated and a speed of the internal combustion engine that is greater than a predetermined one

Threshold value is ThrO, it is determined that this "tire" state 3-1 is exited and the internal combustion engine changes to the "start phase" state 3-2. Alternatively, if the "tire" state 3-1 occurs Ignition is switched off, no transition to the

"Start phase" state, but a transition to the "phase out" state 3-5.

The state "start phase" 3-2 is used to get the internal combustion engine to run on its own. If this does not succeed, that is, if the internal combustion engine is "stalled", which means that the speed of the internal combustion engine remains below a predefinable threshold value Thrl for a certain minimum time, the system returns to the "ready" state 3-1 If, on the other hand, the start phase is successfully completed, that is to say if the speed of the internal combustion engine rises above a predeterminable second threshold value Thr2, then a transition takes place within the second layer n = 2 of the state machine 12 from the “start” operating state 2-8 to the operating state "Normal operation" 2-9.

More specifically, after the start phase, the internal combustion engine then initially changes to an "idle" state 3-3 in the third layer n = 3 of the state machine, as shown in FIG. 2. Depending on the driver's wish for a vehicle in which the internal combustion engine is installed, or depending on the driving situation, the operating state of the

Internal combustion engine during the "normal operation" state 2-9 between the sub-operating states "idle" 3-3 and "accelerating" 3-4. If the internal combustion engine 20 is "stalled" while it is in the "normal mode", a transition takes place within the layer n = 2

Operating state "Start" 2-8 and more precisely a transition to the state "Ready" 3-1 within layer n = 3. If, on the other hand, the "normal operation" state 2-9 is properly ended by switching off the ignition, the internal combustion engine goes into a state in layer n = 2

"Caster" 2-10 over. Within the operating state "run-on" 2-10, after switching off the ignition, the machine first changes to the "run-down" state 3-5 in shift n = 3. This condition is characterized by the fact that the ignition is switched off

However, the internal combustion engine is still running, which means that its speed is still not zero. Only when the speed of the internal combustion engine falls below a predetermined threshold value Thr3 does the internal combustion engine 20 leave this “run-down” state 3-5 and change to a “end” state 3-6 within the third layer n = 3. This state marks the final shutdown of the internal combustion engine, although the ignition is already switched off and the speed is 0, but certain units, such as a fan, can still run on, for example to cool the internal combustion engine.

As soon as the "run-on" state has ended, the machine changes to the state within the second shift

"Standby" 2-7. This behavior applies if the ignition is not switched on again during the "run-on" state 2-10. If, however, the ignition is switched on again in the second shift n = 2 during this "after-running" state 2-10, there are three alternative procedures for controlling the internal combustion engine. A first alternative is that the internal combustion engine changes from the "run-on" state 2-10 to the "start" state 2-8 within the second layer n = 2. With regard to the third layer n = 3, it is irrelevant for this change whether the internal combustion engine 20 is in the "run-down" state 3-5 or in the "end" state 3-6 when the ignition is switched on again; in both cases

Internal combustion engine when the ignition is switched on in the "ready" state 3-1. As an alternative, there is the possibility of leaving the "motor control" state 1-6 and of going into a "resef" state 1-2 of the control unit 10 for the internal combustion engine 20. As a third alternative, there is the possibility of going into a "switched off" state 1 -1 of the control unit 10. In addition to the operating state "motor control" 1-6, which, as described, includes all the essential operating states of the internal combustion engine, the state machine 12 can also include various operating states of the control unit 10 for the internal combustion engine 2 shows the states "switched off" 1-1, "reset" 1-2, "booting" 1-3, "initialization" 1-4 and "shutting down" 1-5, as can already be seen from the structure of the reference symbols , these states are also ranked equal to the state "motor control" 1-6 in the first layer n = 1 of the state machine 12.

The transitions between these individual states of the control unit 10 of the internal combustion engine and also the transitions between these states and the above-described states of the internal combustion engine are briefly described below.

The starting point for considering the state machine 12 described is preferably a situation in which a computer or a microcontroller in the control unit 10, on which a computer program for executing the claimed and described method runs, is switched off. If the control device 10 is installed together with the internal combustion engine 20 in a vehicle, the computer is then, for example

switched off as long as the doors of the vehicle, in particular the driver's door, are still closed or another defined wake-up event has not yet occurred. Such a "switched off" state is designated by the reference number 1-1 in Figure 2. However, as soon as the driver's door in particular is opened, a switch is actuated which causes the control device 10 to leave this state 1-1 and into one "Resef 'state 1-2 to pass. During this state 1-2, the control unit 10 is put into a predefined initial state. The control unit 10 then automatically changes from the "resef" state 1-2 to the "booting" state 1-3, in which the control unit is started up. Within the "booting" state, the control unit 10 sequentially goes through the "pre-initialization" states. .

“Speed initialization” 2-2 and “post-initialization” 2- 3. After completion of the “booting” state 1-1, the control unit 10 again automatically changes to the “initialization” state 1-4, with various adaptations and in particular pre-setting certain ones Variables take place. This is done by sequentially going through the states "standard boats" 2-4, "customer boats" 2-5 and "operating system preparation" 2-6. At the end of the "initialization" process, control unit 10 automatically goes into the state

"Motor control" 1-6 in the first layer n = 1 over. More precisely, the control unit then changes to the "Standby" state 2-7 in layer n = 2.

From the "standby" state 2-7, the internal combustion engine is normally started after the ignition is switched on, as has been described in detail above. In addition, however, as a rule, various conditions are also preprogrammed, when the internal combustion engine does not enter the state from the “standby” state 2-7

"Ready" 3-1, but changes to the "shutdown" state 1-5 of control unit 10. This is particularly the case if the "standby" state 2-7 was assumed after the after-run state 2-9 was left. In the "shutdown" state, the control unit is prepared for its shutdown. When the "shutdown" state has ended, the control unit automatically returns to the "switched off" state 1-1. If, however, the ignition is switched on again during the "shutdown" state or another equivalent event occurs, the control unit 10 changes to the "Reset" state 1-2 in order to automatically go from there to the state "as described above" Boot ".

Claims

Expectations

1. A method for operating an internal combustion engine of a specific type (20) according to a state machine (12), which specifies various possible operating states for operating the internal combustion engine of the specific type and permitted transitions between the operating states, the operating states in the state machine (12) in several Layers (1 ... n, n + 1, ... N) are grouped and the layers are hierarchically structured in such a way that at least one layer (s) is followed by at least one further layer (n + 1), which is at least one

Sub-operating state for an operating state assigned to the layer (s), characterized in that

the layer (s) and all layers (0 ... n-1) upstream of it in the hierarchical structure of the state machine (12) each represent operating states which the internal combustion engine (20) of the particular type has in common with internal combustion engines of another type; and

the further layer (n + 1) as well as all layers downstream of it in the hierarchical structure of the state machine (n + 2 ... N)

represent that are specific to the internal combustion engine (20) of the particular type.

2. The method according to claim 1, characterized in that the individual layers (0 ..., n, n + 1, ... N) of the state machine (12) comprise the following operating states of the internal combustion engine (20):

the states "Standby", "Start", "Normalbetrieb" and "Nachlauf" represent sub-operating states for the operating state "Start"; the states "idling" and "accelerating" represent sub-operating states to the operating state "normal operation"; the states "run-out" and "end" represent sub-operating states to the operating state "run-on"; wherein the states "pre-glow" and "non-preheat" represent an exemplary sub-operating state to the operating state "ready"; wherein the first to third layers (n = 1, 2, 3) represent operating states which the

Engine of the certain type in common with engines of another type; and wherein the fourth layer (n = 4) represents operating conditions specific to the internal combustion engine (20) of the particular type.

3. The method according to claim 2, characterized in that within the third layer (n = 3) the internal combustion engine (20) only then changes from the "ready" state (3-1) to the "start phase" state (3-2) , if starting of the internal combustion engine (20) is recognized by a starter (15) and that a transition from the "start phase" state (3-2) back to the "ready" state (3-1) only takes place if the speed of the internal combustion engine (20) is less than a first predeterminable threshold value (Thrl) for a predefinable period of time.

4. The method according to claim 3, characterized in

that the internal combustion engine is initially in a "standby" state (2-7) within the second layer (n = 2) before it changes from the "standby" state to the "ready" state (3-1) when the Ignition for the internal combustion engine is switched on.

5. The method according to claim 2, characterized in that within the third layer (n = 3) a transition of the internal combustion engine (20) from the "idle" state (3-3) to the "accelerate" state (3-4) and vice versa is possible, in particular, depending on the driver's specifications

Vehicle in which the internal combustion engine (20) is operated.

6. The method according to claim 2, characterized in that within the third layer (n = 3) the internal combustion engine (20) only then from the state

"Runout" (3-5) changes to the "End" state (3-6) when the ignition is switched off and the engine speed has become less than a third threshold Thr3 near zero.

7. The method according to claim 2, characterized in that within the second layer (n = 2) the internal combustion engine (20) changes from the "start" state (2-8) directly to the "after-run" state (2-10), when the ignition of the vehicle in which the internal combustion engine is operated is switched off or equivalent information is given to the control device.

8. The method according to claim 7, characterized in that the internal combustion engine within the third layer (n = 3) from the "ready" state (3-1) or from the "start phase" state (3-2) to the "runout" state "(3-5) passes when the ignition is turned off or equivalent information is given to the control unit.

9. The method according to claim 2, characterized in that within the second layer (n = 2) the internal combustion engine from the "start" state (2-8) directly into the "normal operation" state (2-9) when the speed the internal combustion engine exceeds a predetermined second threshold value (Thr2).

10. The method according to claim 9, characterized in that the internal combustion engine within the third layer (n = 3) from the "start phase" state (3-2) to the "idle" state (3-3) when the speed of the

Internal combustion engine exceeds the second threshold.

11. The method according to claim 2, characterized in that within the second layer (n = 2) the internal combustion engine from the state "normal operation" (2-9) goes directly into the state "start" (2-8) when the speed the internal combustion engine falls below a predetermined first threshold value (Thrl).

12. The method according to claim 11, characterized in that the internal combustion engine from the state "normal operation" (2-9) in the second layer (n = 2) to the state "ready" (3-1) within the third layer (n = 3) passes when the engine speed falls below the first threshold (Thrl).

13. The method according to claim 2, characterized in that within the second layer (n = 2)

Internal combustion engine returns from the "run-on" state (2-10) directly to the "start" state (2-8) when the ignition is switched on again.

14. The method according to claim 13, characterized in that when the ignition is switched on again, the internal combustion engine within the third layer (n = 3) either from the "leak" state (3-5) or from the

"Exit" state (3-6) changes to "Ready" state (3-1); or that the internal combustion engine, when the overrun has ended, within the third layer (n = 3) either from the "run-down" state (3-5) or from the "end" state (3-6) to the state " Standby "(2-7) goes over.

15. The method according to any one of the preceding claims, characterized in that the state machine (12) in addition to the operating states of the 'internal combustion engine also maps various operating states of the control unit of the internal combustion engine.

16. The method according to claim 15, characterized in that the first layer (n = 1) of the state machine (12) in addition to the state "motor control" (1-6) for the internal combustion engine also the states "switched off" (1-1), "Reset" (1-2), "boot" (1-3), "initialization" (1-4) and "shutdown" (1-5) for the control unit (10) of the internal combustion engine (20).

17. The method according to claim 16, characterized in that the control unit (10) for the internal combustion engine (20) then changes from the "switched off" state (1-1) to the "reset" state (1-2) when the control unit (10) is switched on, in particular by activating a switch in a door of the vehicle in which the control device is installed.

18. The method according to claim 16 or 17, characterized in that within the first layer (n = 1) a transition from the "initialization" state (1-4) to the "motor control" state (1-6) takes place when the Initialization is complete.

19. The method according to claim 18, characterized in that under the condition that the initialization

is completed, the transition from the "initialization" state (1-4) or either to the "standby" state (2-7) or "start" (2-8) takes place in the second layer (n = 2) and that a jump to the "Start" state (2-8) jumps directly to the "Ready" state (3-1) in the third layer (n = 3).

20. The method according to claim 16, characterized in that a transition from the "standby" state (2-8) for the internal combustion engine (20) to the "shutdown" state (1-5) for its control unit takes place after a predefinable condition.

21. The method according to claim 16, characterized in that the internal combustion engine from the state "run-on" (2-10), in which the ignition is switched off, optionally in one of the states "reset" (1-2), "booting" (1-3) or "Initialization" (1-4) goes over when the ignition is switched on again.

22. The method according to any one of claims 16-21, characterized in that the state "boot" (1-3) the sub-states "standard boats" (2-1), "customer boats" (2-2) and "operating system preparation" (2 -3), which are run through in the order mentioned during the boot process.

23. The method according to any one of claims 16-22, characterized in that the state "initialization" (1-4) the sub-states "pre-initialization" (2-4), "speed initialization" (2-5) and "post-initialization" (2nd -6) which are run through sequentially during the initialization process in the order mentioned.

24. Computer program for a control device (10)

Internal combustion engine (20), in particular of a motor vehicle, with a program code which is suitable according to the method

to perform one of claims 1-23 when it is executed on a computer, preferably a processor within the control unit (10).

25. The computer program according to claim 24, wherein the program code is stored on a computer-readable data carrier.

26. Control device (10) for an internal combustion engine (20), which is designed to control the internal combustion engine according to the method according to one of claims 1-23.