SE537308C2 - Method and system for controlling an internal combustion engine through control of combustion in an internal combustion chamber during the current combustion cycle - Google Patents

Abstract

The present invention relates to a method of controlling an internal combustion engine (101), said combustion engine (101) comprising at least one combustion chamber (201) and means (202) for supplying fuel to said combustion chamber (201), wherein combustion in said combustion chamber (201) occurs in combustion cycles. The method is characterized by: during a first part of a first combustion cycle, estimating a first mat on nitrogen oxides (NO) resulting from combustion during said first combustion cycle, and based on said first mat, regulating combustion during a subsequent part of said first combustion cycle. The invention also relates to a system and a vehicle.

Description

FIELD OF THE INVENTION Field of the Invention systems and a vehicle, as well as a computer program and a computer program product, which implement the method according to the invention.

Background of the Invention The following description of the invention constitutes a background description of the invention, and thus does not necessarily constitute a prior art.

Due to increased government interests regarding pollution and air quality, emission standards and emission regulations regarding emissions from internal combustion engines have been developed in many jurisdictions.

Such emission regulations often constitute sets of requirements which define acceptable limits for exhaust emissions in vehicles equipped with internal combustion engines. For example, levels of emissions of nitrogen oxides (NO), hydrocarbons (HC) and carbon monoxide (CO) are often regulated. These emission regulations can also e.g. manage the presence of particles in exhaust emissions.

In an effort to comply with these emission regulations, the exhaust gases caused by the combustion engine's combustion are treated (purified). For example. can a s.k. catalytic purification process is used, why also exhaust gas treatment systems, as in e.g. vehicles and other vehicles, usually include one or more catalysts and / or other components. For example. 1,537,308 exhaust gas treatment systems in vehicles with diesel engines often include particulate filters.

The occurrence of undesired compounds in the exhaust gas resulting from the internal combustion engine is caused to a large extent by the combustion process in the internal combustion engine's combustion chamber, at least partly due to the amount of industry that is involved in the combustion. For this reason, as well as the fact that a very large part of the heavy economy's operating economy in particular is governed by the amount of fuel consumed, Oven is committed to streamlining the combustion engine's combustion in order to reduce emissions and fuel consumption.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of controlling an internal combustion engine. This object is achieved by a method according to claim 1.

The present invention relates to a method for controlling an internal combustion engine, said combustion engine comprising at least one combustion chamber and means for supplying fuel to said combustion chamber, wherein combustion in said combustion chamber takes place in combustion cycles. The process Or characterized in that: - during a first part of a first combustion cycle, a first mat is estimated on nitrogen oxides NO resulting from combustion during said first combustion cycle, and - based on said first mat, combustion is regulated during a subsequent part of said first combustion.

As mentioned above, the efficiency of the internal combustion engine has an impact on the overall economy of a vehicle, in particular with 2,537,308 for heavy vehicles. For this reason, it is often undesirable for combustion to be controlled in a manner that results in as efficient combustion as possible.

The combustion can also be controlled with regard to the desired exhaust properties. For example. the time of injection and / or the amount of injected industry can be controlled to influence the course of the combustion and thus e.g. exhaust gas temperature and / or composition. In some cases, it can e.g. be desired with a higher exhaust temperature at the expense of the efficiency of the internal combustion engine in order to obtain the desired function for one or more components in the after-treatment system. It may also be the case that the total efficiency, including the exhaust aftertreatment, can also be improved in the event of an accumulation of the efficiency of the internal combustion engine, e.g. pga. reduced access to reducing agents, such as e.g. urea supply for reduction of nitrogen oxides NOR, ie. nitrous oxide NO and nitrogen dioxide NO2, respectively, which are generally included in the collective term nitrogen oxides NOR, in the exhaust stream. It may also be acceptable in certain situations with a narrowing of the overall efficiency, e.g. to achieve somewhat undesirable behavior in the finishing system.

The present invention relates to a control of the combustion process in which the course of an ongoing combustion cycle can be regulated during ongoing combustion against a desired result of the combustion. In particular, the course of the combustion is controlled with respect to a resulting nitrogen oxide content during the combustion.

The control according to the present invention can be achieved by estimating during a first part of a first combustion cycle a first mat on nitrogen oxides NOR, such as a content and / or an amount / mass of the resulting nitrogen monoxide (NO) 3,537,308 and / or nitrogen dioxide (NO2). , which results from combustion during said first combustion cycle, and - based on said first mat, the combustion is regulated during a subsequent part of said first combustion cycle in order to affect the resulting nitrogen oxides NOR during the current combustion cycle.

By proceeding in this way, the nitrogen oxides resulting from the combustion can be regulated NO, so that the desired regulation such as e.g. minimization of nitrogen oxides NO to a large extent can be obtained during combustion. For example. it may be unfortunate that the total amount of nitrogen oxides NO to a maximum amounts to the flag applicable amount. For example. Nitrogen oxide emissions can be regulated in order to be as close to the legislation as possible when it comes to nitrogen oxide emissions, with a positive impact on fuel consumption as a result.

Alternatively, it may be unwise to try to reduce / minimize the nitrogen oxides NOR resulting from the combustion as much as possible. Thus, according to the invention, the nitrogen oxides usually resulting from combustion can be regulated, while the nitrogen-free nitrogen oxides NO can already be regulated during the combustion process, e.g. to reduce the load on finishing systems, and e.g. in order to reduce the use of reducing (additive) agents such as urea-containing additives.

The control according to the present invention can be achieved by determining during a first part of a combustion cycle a parameter value representing a quantity in the combustion, such as e.g. a pressure radiating in the combustion chamber. Based on this parameter value, such as e.g. pressure, the resulting nitrogen oxides NO during the combustion cycle, not only for the already past part of the combustion cycle but also for the next part of said combustion cycle, can be estimated, the combustion during the subsequent part of the combustion cycle then being regulated with respect to the resulting nitrogen oxides. ., dar e.g. the combustion during the subsequent part of said combustion cycle can be regulated in order to compare with estimated resulting nitrogen oxides NC. reduce the resulting nitrogen oxides NO so that the nitrogen oxides NO actually resulting during the combustion cycle e.g. can be reduced in relation to estimated nitrogen oxides NO ..

When regulating the combustion, the combustion may be arranged to be regulated with respect to some applicable quantity, such as e.g. pressure and / or temperature of the combustion chamber, whereby the resulting nitrogen oxides NO can be regulated by regulating said quantity, such as e.g. pressure and / or temperature, where the control is performed based on a relationship between the pressure and / or the temperature during the combustion and the resulting nitrogen oxides NO. regulation can be performed based on how the combustion temperature varies during combustion, where the combustion e.g. as far as possible, the applicable pressure / temperature curve can be caused to follow, the pressure / temperature variation being controlled by influencing the combustion during the current combustion cycle so that an undesired variation is obtained during the combustion. The regulation can e.g. be arranged to be controlled against an empirical or otherwise determined pressure / temperature curve (save), alternatively e.g. against a limitation of the maximum temperature and / or the maximum pressure that arises during combustion.

The control of the combustion can also be arranged to be performed individually for each cylinder, and it is also possible to control a combustion in a subsequent combustion cycle based on information from one or more previous combustion processes.

This type of regulation has the advantage that e.g. differences between different cylinders can be detected and compensated with the help of individual adjustment of parameters for a specific cylinder, such as opening time for injection nozzles, etc. However, it can also be the case that different control of different cylinders can be difficult, e.g. to steer certain cylinders towards meeting any criterion, and other cylinders against any other applicable criterion, which can also be achieved according to the invention. Furthermore, only one or a subset of the cylinders can be arranged to be controlled according to the invention, while the combustion in other cylinders can be carried out in the usual or otherwise applicable manner.

According to one embodiment, an injection schedule is established which results in at least half of the desired work being exhausted to ensure that the exhausted work cannot be regulated to excessively low levels when generated nitrogen oxides NO are regulated.

The method according to the present invention can e.g. implemented using one or more FPGAs (Field-Programmable Gate Array) circuits, and / or one or more ASIC (application-specific integrated circuit) circuits, or other types of circuits that can handle the desired computational speed.

Additional features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1A schematically shows a vehicle to which the present invention can be applied.

Fig. 1B shows a control unit in the control system for the vehicle shown in Fig. 1A.

Fig. 2 shows the internal combustion engine of the vehicle shown in Fig. 1A in more detail.

Fig. 3 shows an exemplary method according to the present invention.

Fig. 4 shows an example of an estimated temperature pair for a color burn.

Figs. 5A-B show an example of control in situations with more than three injections.

Fig. 6 shows an example of an MPC control.

Fig. 7 illustrates an alternative method for estimating pressure change during a combustion process.

Detailed Description of Embodiments Fig. 1A schematically shows a driveline in a vehicle 100 according to an embodiment of the present invention. The driveline comprises an internal combustion engine 101, which is connected in a conventional manner, via a shaft outgoing on the internal combustion engine 101, usually via a flywheel 102, to a gearbox 103 via a clutch 106.

The internal combustion engine 101 is controlled by the vehicle's control system via a control unit 115. Likewise, the clutch 106, which e.g. can be constituted by an automatically controlled clutch, and the gearbox 103 of the vehicle's control system by means of one or more applicable control units (not shown). Of course, the vehicle's driveline can also be of another type such as e.g. of a type with 7 537 308 conventional automatic gearbox or of a type with a manually geared gearbox etc.

A shaft 107 emanating from the gearbox 103 drives drive wheels 113, 114 in the usual manner via end shaft and drive shafts 104, 105. Fig. 1A shows only one shaft with drive wheels 113, 114, but in the usual way the vehicle may comprise more than one shaft provided with drive wheels, as well as one or more additional axles, such as one or more stand axles. The vehicle 100 further includes an exhaust system with a post-treatment system 200 for conventional treatment (purification) of exhaust emissions resulting from combustion in the combustion chamber (e.g., cylinders) of the combustion engine 101.

Post-treatment systems often involve some form of catalytic purification process, where one or more catalysts are used to purify the exhaust gases. Vehicles with a diesel engine also often include a diesel particulate filter (DPF) to capture soot particles formed during the combustion of fuel in the combustion engine's combustion chamber. Furthermore, after-treatment systems in vehicles of the type shown may include an oxidation catalyst (DOC). The oxidation catalyst DOC has several functions, and is normally used primarily to oxidize the remaining hydrocarbons and carbon monoxide in the exhaust stream to carbon dioxide and water during the aftertreatment of the exhaust gas. The oxidation catalyst can also e.g. oxidize nitrogen monoxide (NO) to nitrogen dioxide (NO2) Finishing systems can also include more / other types of components than what has been exemplified above, as well as fewer components. For example. For example, the post-treatment system 200 may include a selective catalytic reduction (SCR) downstream of the particulate filter. SCR catalysts use ammonia (NH3), or a composition from which ammonia can be generated / formed, as an additive to reduce the amount of nitrogen oxides NO in the exhaust gas stream.

Furthermore, internal combustion engines in vehicles of the type shown in Fig. 1A are often equipped with controllable injectors to supply the desired amount of fuel at the desired time in the combustion cycle, as at a specific piston position (crank angle) in the case of a piston engine, to the internal combustion engine combustion engine.

Fig. 2 schematically shows an example of an fuel injection system for the combustion engine 101 exemplified in Fig. 1A. The fuel injection system consists of a so-called Common Rail systems, but the invention is equally applicable to other types of injection systems. Fig. 2 shows only a cylinder / combustion chamber 201 with a piston 203 acting in the cylinder, but the combustion engine 101 in the present example consists of a six-cylinder internal combustion engine, and can generally consist of an engine with an arbitrary number of cylinders / combustion chamber, such as e.g. . any number of cylinders / combustion chambers in the range 1-20 or more. The combustion engine further comprises at least one respective injector 202 for conventional combustion chamber (cylinder) 201. Each respective injector is thus used for injection / supply of fuel into a respective combustion chamber 201. Alternatively, two or more injectors per combustion chamber may be used. The injectors 202 are individually controlled by respective actuators (not shown) arranged at each injector, which are based on received control signals, such as e.g. from the control unit 115, controls the opening / closing of the injectors 202.

The control signals for controlling the opening / closing of the injectors 202 by the actuators can be generated by any applicable control unit, as in this example by the motor control unit 115. The motor control unit 115 thus determines the amount of fuel to be actually injected at any given time, e.g. . based on the prevailing operating conditions of the vehicle 100.

The injection system shown in Fig. 2 thus consists of a so-called Common Rail system, which meant that all injectors (and thus combustion chambers) are supplied with fuel from a common fuel line 204 (Common Rail), which with the help of a fuel pump 205 is filled with fuel from a fuel tank (not shown) at the same time as the fuel in the rudder 204, also with the aid of the fuel pump 205, is pressurized to a certain pressure. The highly pressurized fuel in the common tube 204 is then injected into the combustion chamber 201 of the internal combustion engine 101 at the opening of the respective injector 202. Several openings / rods of a specific injector can be made during one and the same combustion cycle. Furthermore, each combustion chamber is provided with a respective pressure sensor 206 for emitting signals of a pressure radiating in the combustion chamber to e.g. the control unit 115. The pressure sensor can e.g. be piezo-based and should be so fast that it can emit crank angle-resolved pressure signals, such as e.g. at every 10, every 5th or habit crank angle degree or other applicable interval, such as e.g. an oftare.

With the aid of systems of the type shown in Fig. 2, the combustion during a combustion cycle in a combustion chamber can be controlled to a large extent, e.g. by utilizing multiple injections, where injection times and / or duration can be regulated, and where data from e.g. the pressure sensors 206 can be taken into account in the control. According to the present invention, e.g. injection times and / or duration of the respective 537 308 injection and / or injected fuel quantity during the incineration based on data from the incineration in order to regulate the combustion with respect to the nitrogen oxides NO generated during the combustion. Fig. 3 shows an exemplary method 300 according to the present invention, in which the method according to the present example is arranged to be performed by the motor control unit 115 shown in Figs. 1A-B.

Generally, control systems in modern vehicles consist of a communication bus system consisting of one or more communication buses for interconnecting a number of electronic control units (ECUs) such as the control unit, or controller, 115, and various components arranged on the vehicle. As such, such control systems may include a large number of control units, and the responsibility for a specific function may be divided into more than one control unit.

For the sake of simplicity, in Figs. 1A-B, only the motor control unit 115 in which the present invention is implemented in the embodiment shown is shown. However, the invention can also be implemented in a control unit dedicated to the present invention, or in whole or in part in one or more other control units already existing in the vehicle. In view of the speed at which calculations according to the present invention are performed, the invention can be arranged to be implemented in a control unit which is specially adapted for real-time calculations of the type as below. Implementation of the present invention has shown that e.g. ASIC and FPGA solutions that illuminate and select can handle calculations according to the present invention.

The function of the control unit 115 (or the control unit (s) to which the present invention is implemented) according to the present invention may, in addition to being dependent on sensor signals from the pressure sensor 202, e.g. depend on signals 11 537 308 from other control units or sensors. In general, control units of the type shown are normally arranged to receive sensor signals from different parts of the vehicle, as well as from different control units arranged on the vehicle.

The control is often controlled by programmed instructions. These programmed instructions typically consist of a computer program, which when executed in a computer or controller causes the computer / controller to perform the desired control, such as the process steps of the present invention.

The computer program usually forms part of a computer program product, where the computer program product comprises a suitable storage medium 121 (see Fig. 1B) with the computer program stored on said storage medium 121. Said digital storage medium 121 may e.g. consists of someone from the group: ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically Erasable PROM), a hard disk drive, etc., and be arranged in or in connection with the control unit, the computer program being executed by the control unit. By following the instructions of the Second Computer Program, the behavior of the vehicle in a specific situation can thus be adapted.

An exemplary control unit (control unit 115) is shown schematically in Fig. 15, wherein the control unit may in turn comprise a calculating unit 120, which may be constituted by e.g. any suitable type of processor or microcomputer, e.g. a Digital Signal Processor (DSP), one or more Field-Programmable Gate Array (FPGAs) circuits, or one or more circuits with an Application Specific Integrated Circuit (ASIC) function.

The calculation unit 120 is connected to a memory unit 121, which provides the calculation unit 120 e.g. the stored program code and / or the stored data calculation unit 1 12 537 308 need to be able to perform calculations. The calculation unit 120 is also arranged to store partial or end results of calculations in the memory unit 121.

Furthermore, the control unit is provided with devices 122, 123, 124, 125 for receiving and transmitting input and output signals, respectively. These input and output signals may contain waveforms, pulses, or other attributes, which of the input signals receiving devices 122, 125 may be detected as information for processing the calculation unit 120. The output signals 123, 124 for transmitting output signals are arranged to convert calculation results from the calculation unit. 120 to output signals for transmission to other parts of the vehicle control system and / or the component (s) for which the signals are intended. Each of the connections to the devices for receiving and transmitting input and output signals, respectively, may be one or more of a cable; a data bus, such as a CAN bus (Controller Area Network bus), a MOST bus (Media Oriented Systems Transport), or any other bus configuration; or by a wireless connection.

Returning to the method 300 shown in Fig. 3, the process starts in step 301, where it is determined whether the control according to the invention of the combustion process is to be carried out. The regulation according to the invention can e.g. be arranged to be carried out continuously as soon as the internal combustion engine 101 is started. Alternatively, the regulation can be arranged to be performed e.g. as long as the combustion engine combustion is not to be regulated according to any other criterion. For example. There may be situations where it is undesirable for regulation to be carried out based on factors other than the nitrogen oxides NO resulting from the combustion in the first place. According to one embodiment, simultaneous control of the combustion is performed with respect to the resulting kyave oxides NO and at least one additional control parameter. For example. a balancing can be made, where the priority of the control parameters when fulfilling the desired control result e.g. may be arranged to be controlled according to any applicable cost function.

The method according to the present invention thus consists of a method for controlling the internal combustion engine 101 while combustion takes place in said combustion chamber 201 in combustion cycles. As is true, the term combustion cycle is defined as the steps involved in combustion at an internal combustion engine, such as e.g. two-stroke two-stroke engine and four-stroke engine respectively. The term also includes cycles where no fuel is actually injected, but where the combustion engine spirit is driven Yid somewhat varytal, such as ay the vehicle's drive wheel via the driylin at e.g. relaxation. Ie. even if no injection of fuel is carried out, a combustion cycle still takes place for e.g. habit two vary (for four-stroke engine), or e.g. vane vary (two-stroke engine), which rotates the output shaft of the internal combustion engine. The opposite grille ayen other types of internal combustion engines.

In step 302 it is determined whether a combustion cycle has or will be started, and when so, the procedure proceeds to step 303 at the same time as a parameter in the representative injection number is set equal to one.

In step 303, an injection schedule is established, e.g. in a completely conventional way based on e.g. a desirable work done. Alternatively, e.g. an injection scheme is established which is expected to result in a desired generation of cyave oxides NOR during combustion, such as e.g. an injection scheme that is expected to result in a maximum of a certain amount of nitrogen oxides NOR, or generally a minimization of 14,537,308 generated nitrogen oxides NO during the combustion cycle combustion.

In general, it is important that the supply of fuel both in terms of quantity and in what way, ie. the one or more fuel injections to be performed during the combustion cycle are normally predefined, e.g. depending on the work (torque) that the internal combustion engine must perform during the combustion cycle, since the change of the established injection schedule is not carried out during an ongoing combustion cycle according to prior art. Predefined injection schedules can e.g. are tabulated in the vehicle's control system for a large number of operating cases, such as different engine speeds, different work required, different combustion air pressures, etc., where tabulated data e.g. may have been produced by appropriate tests / feeds at e.g. development of an internal combustion engine and / or vehicle, whereby an appropriate injection schedule can be selected based on prevailing conditions.

According to one embodiment, injection schedules may be developed, e.g. through applicable, such as empirical, tests / feeds, where several injection schedules can be defined for a specific operating condition and to result in a certain amount of work, but where different injection schedules can be developed to meet different additional criteria, such as e.g. a criterion for the nitrogen oxides NOR, and / or other parameters resulting from the combustion. NOx emissions may thus have been measured for different injection schedules and then entered into the vehicle's control system, whereby an injection schedule can initially be determined by table look-up or in another applicable way based on e.g. a drilling value for NOx emissions. Thus, nitrogen oxide determinations can be challenged in advance for a large 537,308 number of operating cases1, where these determinations can be used in the selection of the injection schedule.

According to one embodiment, however, an injection scheme is initially applied which is determined based on e.g. only requested work.

These injection schedules can consist of the number and properties of the injections in the form of e.g. time (crank angle law) for start of injection, length of injection, injection pressure and / or quantity, etc., and thus are stored for a large number of operating cases in the vehicle's control system, and e.g. be protruding / fed with the grind to meet some criterion, such as a certain exhausted work, a certain resulting exhaust temperature or other applicable criterion.

According to an embodiment of the invention, the injection scheme can also be arranged that before the combustion is started, i.e. even before a first industry injection is carried out, is determined by applicable calculations, such as e.g. as below, where e.g. different pre-defined injection schedules can be compared with each other to determine a most preferred injection schedule, and where e.g. undesired work and / or desired emissions (such as the high / low proportion of nitrogen oxides NOR) can be parameters in the calculations.

According to the present embodiment, in step 303, such a predetermined injection schedule is applied, where this predetermined injection schedule is selected based on something applicable as above, e.g. by table1 lookup, where according to the above different injection schedules can, but do not need, be defined where different amounts of nitrogen oxides NO are expected during combustion at the same time as e.g. the same work 16 537 308 on the output shaft of the internal combustion engine is performed, but where the injection schedule can therefore also be arranged to e.g. only take undesirably exhausted work into account, whereby regulation of generated nitrogen oxides NO can be arranged to be performed only after a first injection or first part of an injection has been performed.

Since specific assumed ratios are likely to result in the same preferred injection schedule as usual, it may be advantageous to select an injection schedule for a combustion cycle by flaking type of storage and thereby reduce the calculation load, whereby calculation e.g. as below can thus be performed only after injection has begun. In addition to the following examples of how the injection schedule can be determined, other models with a corresponding function can alternatively be applied.

The amount of nitrogen oxides NO that is desired, or the maximum desired, during combustion can be determined in some appropriate way, e.g. of an overall function that demands flagon applicable level for NOx emissions. This level can e.g. is represented by a request for minimized NOx emissions, but also by a request for higher NOx emissions, e.g. if this is for flagon reason judged to be undesirable for subsequent reactions in the post-treatment system, or e.g. a level corresponding to statutory levels of nitrogen oxide emissions.

Thus, fuel injection is normally performed according to an injection schedule where a plurality of injections may be arranged to be performed during one and the same combustion cycle. This means that the injections can be relatively short. For example. Injection systems with 5-fuel injections / combustion occur, but the number of fuel injections during a combustion cycle can also be 17 537 308 significantly larger than that, such as e.g. in the order of 100 industry injections. The number of possible injections is generally controlled by the speed of the organs with which the injection is performed, ie. in the case of Common Rail systems hut quickly the injectors can be opened shut down.

According to the present example, at least two fuel injections are performed during one and the same combustion cycle, but as has been mentioned and as shown below, several injections can be arranged to be performed, as well as only one.

A first injection is performed, and in step 304 it is determined whether said first injection has been performed, and if so the procedure continues to step 305, then it is determined whether all the injections into hat have been performed.

Since this is not the case in the present example, the procedure proceeds to step 306 while being straightened up with a next injection. In step 306, the pressure in the combustion chamber is determined by using the pressure sensor 206. Furthermore, by using the pressure sensor 206, the pressure in the combustion chamber can be determined substantially continuously, as at applicable intervals, e.g. every 0.1-10 weaving angle degrees.

The process of combustion can be generally described with the pressure change in the combustion chamber which the combustion gives rise to. The pressure change during a combustion cycle can be represented by a pressure gauge, ie. a representation of the hut pressure in the combustion chamber varies during combustion. As the combustion progresses, as expected, the pressure in the combustion chamber will be equal to what was initially expected or estimated. SA as soon as the combustion deviates from expected combustion, however, the pressure will deviate from the estimated pressure from 18 537 308. In addition, the combustion during the subsequent part of the combustion cycle, and thus temperature development, will be affected.

In step 306, the pressure pfq, 1 in said combustion chamber 201 is determined for a radiating crank angle pi after said first injection has been performed using said pressure sensor 206, and in step 307 the injection schedule is evaluated and changed if necessary by estimating expected generated nitrogen oxides NO the combustion cycle, which can be performed with the aid of applicable calculations, where a method of performing the calculation is exemplified below. Alternatively, other models with a corresponding function can be applied.

General (jailer that nitrogen oxides NO in a combustion process are mainly formed for three different reasons. Firstly, the industry may include nitrogen, whereby nitrogen will be released during combustion and at least form nitrogen gas N2 and nitrogen oxides NOR. This type of NOx formation can in certain types of combustion and, depending on the type of industry, accounts for a large part of the total amount of nitrogen oxides NO generated during combustion. to NOR formation consists of so-called prompt NOR formation, but this can generally be disregarded as the effect is small in relation to other colds. , consists of the thermal formation of NOR, which may account for in the order of 90-95% or more of the NOR formation during the combustion cycle. t is also primarily this type of NOR formation that can be affected by affecting the combustion, so NOR regulation can be performed with good results by only taking thermal NOx formation into account, which is also performed in the following.

The NOx formation is highly dependent on the combustion temperature, and the actual formation of thermal NO can be described in a selective manner, e.g. according to three main reactions (the undocumented Zeldovich mechanism): N2 + 0. NO + N N + 02. NO + 0 (1) N + OH - NO + H, where the reaction rate is strongly temperature dependent, and where the temperature dependence itself is edge, whereby by knowledge of the (substance) amount of the constituent substances and the temperature amount of nitrogen oxides formed NOx can be estimated .

According to the present invention, NOx formation is estimated by utilizing the above chemical compounds, eq. (1), and by using an estimation of additional combustion data. The calculation therefore requires both knowledge of the available amount of nitrogen N2 and oxygen 02 and also knowledge of access to water H. These can be obtained from the combustion chemistry of the combustion, which is known to those skilled in the art, and in which the required amount of fuel and combustion air and possibly. exhaust gas lining is known, whereby in combination with the fact that the composition of the industry is normally known the quantities for those in eq. (1) the constituent substances can be calculated.

An estimation of the combustion temperature is also required in order for the amount of nitrogen oxides generated NO to be estimated, since the reaction rate is temperature-dependent. Similarly, an estimation of pressure and / or temperature in the combustion chamber is required in order to be able to estimate released nitrogen gas and oxygen, respectively, during combustion by means of the combustion chemistry.

The combustion can, as is the edge for the person skilled in the art, be modeled according to eq. (2): dQ = Kcaltbrate (Q fuel - Q) (2) where Kcalibrate is used to calibrate the model. Calibrate consists of a constant which is usually in the order of 0-1, but may also be arranged to assume second values, and which is determined individually cylinder by cylinder or for a particular engine or engine type, and depends in particular on the design of the injectors nozzles (diffusers ). dQ can also be modeled in other applicable ways, e.g. by also including other parameters, such as e.g. turbulence at the fuel supply, where this can be modeled appropriately.

Qm4 constitutes the energy value for injected industry volume, and Q constitutes combustion energy quantity. The combustion dQ is thus proportional to the injected amount of fuel minus the amount of fuel consumed so far. The combustion dQ can alternatively be modeled by using another applicable model, where one e.g. can also take into account other parameters. For example. the combustion can also constitute a function that depends on a model of turbulence in the supply of air / fuel, which can affect the combustion to varying degrees depending on the amount of air / fuel supplied.

Regarding the industry injections, these can e.g. modeled as a sum of step functions: 21 537 308 U = - (tmj. start) 3 - (P (t (tin]. end) k) (3) k = 0 Bransleflodet matt i tillford mass m at an injection k, ie. how the fuel enters the combustion chamber during the time window u when the injection is performed, expressed in the time elapsed below the crank angle degree p -interval that the injector ax open, for a specific injection k can be modeled as: dm = f (m) u (4) where m constitutes injected industry volume, and f (m) eg depends on injection pressure, etc. f (m) can, for example, be measured or estimated in advance at the edge.

The energy value 0 LHV for the industry, such as diesel or petrol, is generally stated, whereby such a general statement can be used. The energy value can also be specifically specified by e.g. industry's manufacturers, or be approximated for e.g. a country or region. The energy value can also be arranged to be estimated by the vehicle's control system. With the energy value, eq. (2) is released, and the heat release as the combustion proceeds is determined. Thus, the heat release for the next part of the combustion cycle can also be estimated by performing the calculations for expected future injections.

Furthermore, by using a predictive heat release equation, the pressure change in the combustion chamber, e.g. is estimated as: 22 537 308 d (dQydV \ (y - 1) Pthp y - 1P & pi k V cl (P (), where p is the crank angle degree, ie the pressure change is expressed in crank angle degrees, which meant an elimination of the internal combustion engine speed dependence in the calculations. constitutes a parameter that is estimated in advance, or is set to C „a fixed value. y constitutes the heat capacity ratio, ie CC, and / or C; together with the combustion chemistry in order to calculate the effect of each molecule (eg water, nitrogen, oxygen, etc.) on, for example, the total Cp value, whereby this can be determined for the calculations above with good accuracy. Cy is approximated in an applicable way.

Integration of eq. (5) with the following result: dQ y dn (y-1 \ ckp P = PinitialdP = PinitialfyP clip) v) Pjnjgjai constitutes an initial pressure, which before the beginning of compression e.g. may be the ambient pressure of non-turbocharged internal combustion engines, or a radiating combustion air pressure of turbocharged engine. When estimating at a later time during the combustion cycle, Pinithd can be made up of the pressure then determined and aided by the pressure sensor 206, such as the pressure pf. The temperature is higher in the part of the combustion chamber where combustion takes place, and the combustion chamber can be considered as consisting of two zones, where combustion takes place in one zone, with high temperature in this zone as follows, while no combustion, with lower resulting temperature, takes place in the second zone.

The pressure change p as a function of crank angle degree p in a cylinder (combustion chamber) for a combustion cycle can be estimated according to eq. (6) above. Furthermore, by utilizing the estimated pressure, the temperature for the part of the combustion chamber where no combustion takes place can be estimated with the aid of estimated pressure and by utilizing eq. (7), since the temperature for the part of the combustion chamber where no combustion takes place is expressed as: T „, 1 = T„ "Pn + 1) P n (7) dar 7,„ 0 can be the corresponding combustion air temperature for the time / crank angle position dar Pinhthial is determined above, and where n, n + 1, etc. are consecutive times or crank angle positions. and thus K, can be determined as indicated above.

By utilizing eq. (7) the temperature can thus be determined for the part of the combustion chamber where no combustion occurs, where this temperature is affected by ongoing combustion by the effect of the heat release on the pressure which in turn affects the temperature according to eq. (7). When a combustion takes place, the heat release will give rise to a temperature increase in the part (s) of the combustion chamber where combustion takes place. This temperature increase, which is added to it according to eq. (7) the determined temperature for obtaining the combustion temperature can be calculated from the relationship: dQ = mC pdT (8), where dQ constitutes the heat release, which can be determined as above. m consists of combustion mass (ie fuel + air + EGR that is involved in the combustion), which is also determined as above, Cp, ie. specific heat capacity, which can also be calculated as above. dT is the temperature increase as a phase of the combustion at a given combustion mass and at a given Cp value.

Thus, by using equ (8), dT and thus LT can be determined, whereby the increase generated by the combustion at each time / crank angle position can be added to the temperature of the unburned zone given by equ. (7) to obtain the combustion temperature. An example of the variation of the combustion temperature for a combustion cycle is shown in Fig. 4.

When estimation is performed at a later time during combustion, such as e.g. after a first fuel injection has been performed, p, can be subjected to the pressure obtained by the pressure sensor 206, whereby estimation of a subsequent injection can be performed with a starting pressure which takes into account the actual development of previous combustion, whereby a more accurate estimation for subsequent combustion can be performed. The estimated temperature pair for the combustion can thus e.g. look like the temperature pair in Fig. 4. As can be seen, however, the temperature pair can in principle assume an arbitrary appearance depending on how much fuel is injected and when.

Thus, when the combustion temperature has been estimated, concentrations and / or absolute amounts of mainly N2 and O2 can be calculated by using the combustion chemistry, then, by using eq. (1) and its combustion temperature-dependent, generated nitrogen oxides NO can be estimated for the entire combustion cycle, ie. aven for the part lying after the weave angle layer pl. The first injection will presumably give rise to a combustion, and thus a heat release and a pressure increase. If the combustion had proceeded exactly as estimated, the temperature development would be equal to the initially expected. However, the actual combustion temperature pair will in all probability deviate from the predicted temperature pair during the combustion process due to heat losses, deviations from the modeled combustion, etc. such 26 267 308 estimation have been performed before the first injection), and the larger the temperature deviation becomes, the larger the deviation between estimated and actually generated amounts of nitrogen oxides NO will probably be.

Since the pressure / temperature in the combustion chamber after the first injection has been carried out, as at the crank angle position (1) 1 in Fig. 4, may differ from the conditions expected according to the selected injection scheme, the conditions in the combustion chamber will also differ at the time of the next injection. insp2 with a high probability of differing from predicted conditions, for which reason also subsequent combustion will in all probability deviate from the predicted combustion if the previously established injection schedule were still to be used.

Thus, it is not ails certain that desired nitrogen oxide levels will be achieved during the combustion cycle of fuel injection according to the prior art. Thus, it is also not certain that it is the originally established injection schedule that constitutes the most preferred injection schedule for the punishment of achieving desired nitrogen oxide levels.

It is for this reason that the inventive control of the combustion is performed, and according to the present invention, the amount of nitrogen oxides NO that will be generated during the subsequent part of the combustion cycle can be affected after the first injection has been performed.

In step 307, therefore, an injection scheme is fixed again in order to regulate the generation of nitrogen oxides NOR, such as e.g. with the aim of trying to minimize the generated nitrogen oxides NO 27 537 308 during the combustion cycle, or during the remaining part of the combustion cycle.

When determining the injection schedule, the above calculations can be performed for a plurality of injection schedules, whereby then an injection schedule is selected which is expected to result in generated nitrogen oxides NO filling up desired villas.

In the calculations, a plurality of predetermined injection schedules can be compared with each other, alternatively calculations can be performed for different injections where injection parameters such as e.g. injection time / length gradually changed. When evaluating different injection schedules, it can also be advantageous to carry out regulation with the secondary condition that delayed work on the output shaft of the internal combustion engine is maintained, since otherwise it is very likely that little or no work will be performed in which only the generated nitrogen oxides NO are minimized The efficiency regarding the generation of nitrogen oxides NO is optimized at the expense of low output power. According to one embodiment, the control can thus be seen as a minimization problem which consists in finding a control which results in as small an amount of nitrogen oxides NO as is possible for a certain work done by the internal combustion engine.

Control of the combustion temperature in the combustion chamber can thus e.g. is thus performed by regulating the fuel injection, and by performing in step 307 estimating generated nitrogen oxides NO for a number of different injection schedules with varying injection times / injection lengths / number of injections, an injection schedule can thus be established which, as applicable or as high as possible, during combustion.

Thus, in step 307, an injection scheme can be established, such as an injection scheme among a plurality of defined injection schemes, which either minimizes generated nitrogen oxides NO or meets another criterion regarding the nitrogen oxides NOR, where this injection scheme can further be determined individually cylinder by cylinder, e.g. based on sensor signals from at least one pressure sensor in each combustion chamber.

If an injection scheme has been selected in step 307, the process then returns to step 304 for performing the next injection, which also gives rise to a combustion, and thus a heat release and temperature saving, which will in all probability deviate from what has just been estimated in step 307. 307. This also means that the combustion is also likely to be affected by subsequent conditions in the combustion chamber during subsequent injections when the injection is started.

The regulation is then repeated during the current combustion cycle in order to, if necessary, change the injection schedule during the current combustion if the conditions actually prevailing in the combustion chamber deviate from the predicted conditions. By continuously determining the pressure in the combustion chamber by utilizing the pressure sensor 206, actual pressure development can be continuously compared with estimated pressure development, whereby the method may also include initiating a determination of a new injection schedule during an ongoing injection if necessary.

Thus, in step 307, after a subsequent injection has been performed, a new injection strategy for the remaining injections can be calculated, whereby the procedure then returns to step 304 for performing subsequent fuel injection according to the new injection strategy still advanced. with regard to the work to be performed during combustion, which is normally controlled by some overriding process, e.g. in response to a request for a certain driving force from the driver of the vehicle or other function in the vehicle's steering system, such as e.g. a cruise control function. The control can thus be arranged to be performed after each injection in, and when all the injections in have been performed, the procedure Iran repeats step 305 to step 301 for regulating a subsequent combustion cycle.

In the above calculations, after each injection in the current pressure determination p is used, using the pressure sensor 206 as p, 0 as above to estimate the temperature change during combustion when estimating the amount of generated nitrogen oxides NO the combustion chamber, but now thus with data obtained a further bit into the combustion. Ie. p (after the first combustion and in a corresponding manner determined p (pi for subsequent injections, whereby pn = 0 changes in calculations during the combustion cycle, and whereby the fuel injection is adapted to radiating conditions after each injection, with the result that the injection schedule can be changed after each injection. At the same time, the hitherto accumulated generated nitrogen oxides NO can be estimated with good accuracy by using the continuously obtained pressure signals from the pressure sensor 206, and thus the actual pressure pair instead of the estimated during the part of the combustion cycle which has already elapsed, 537 308 If, for example, only a small amount of nitrogen oxides NO has been formed so far, for example a larger expected amount for the subsequent part of the combustion can be accepted, at least in certain situations.

Hitherto, whole injection schedules for residual combustion have been evaluated, but the evaluation may also be arranged to be performed for the next injection only after a previous injection, whereby subsequent injections can be handled gradually with a quick injection as usual in step 307. The injection selected in step 307 can thus consist of only the next injection.

The present invention thus provides a method which adapts the combustion as the combustion proceeds, and generally comprises, based on a first parameter value determined after a first part of the combustion has been carried out, regulating subsequent part of the combustion during one and the same combustion cycle, the combustion being controlled with respect to on the nitrogen oxides NO generated during the combustion process.

According to the present invention, the combustion is thus adapted during ongoing combustion based on deviations from the predicted combustion, and according to one embodiment each time an injection has been performed as long as further injections are to be performed.

According to the method described above, the injection schedule at the beginning of the combustion cycle has been determined based on tabulated values, but according to one embodiment, the injection strategy can be determined in the manner described above even before the industry injection is started, whereby the first injection is performed according to

Furthermore, the process can be arranged to be interrupted when the temperature in the combustion chamber has reached the maximum temperature during the combustion, as essentially all nitrogen oxide generation will have been carried out up to this time, for which subsequent control instead e.g. can be performed completely according to the selected injection schedule, or alternatively performed based on some other applicable criterion.

Furthermore, the regulation has hitherto been described in a manner in which the properties of a subsequent injection are determined based on prevailing conditions in the combustion chamber after the previous injection. However, the control can also be arranged to be performed continuously, whereby pressure determinations can be performed with the aid of the pressure sensor also during pagan injection, and whereby the injection schedule can be calculated and corrected Second until the next injection is drilled. Alternatively, even the ongoing injection can be affected by protruding changes in the injection schedule even in cases where a number of shorter injections are performed. The injection can also consist of a single longer injection, whereby changes of ongoing injection can be performed continuously, e.g. by so-called rate shaping, e.g. by changing the opening area of the injection nozzle and / or the pressure at which fuel is injected based on estimates and measured pressure values during injection. Furthermore, fuel supply during combustion can include only two fuel injections, where e.g. only the second or both injections are regulated e.g. with the help of rate shaping. Rate shaping can also be applied in the case where three or more injections are performed. 32 537 308 The more fuel injections that are carried out during an incineration cycle, the more parameters can be changed, while at the same time tiring work must be maintained. With a large number of injections, the regulation can therefore be relatively complex, since a large number of parameters can be varied and thus would need to be evaluated. For example. a very large number of injections can be arranged to be performed during one and the same combustion cycle, such as a dozen, or even about a hundred injections.

In such situations, there may be several equivalent injection strategies, which are assumed & result in essentially the same amount of generated nitrogen oxides NOR. This introduces an undesirable complexity in the calculations.

According to one embodiment, a control is applied where the closest injection / injection at the time is considered as a separate injection, and subsequent industry injections as a single additional "virtual" injection. This is exemplified in Fig. 5A, where the injection 501 corresponds to inspi as above, the injection 502 corresponds to insp2 as above, and where the remaining injections 503-50 are treated as a single virtual injection 506, i.e. the injection 506 is treated as an injection with an industry quantity substantially corresponding to the total industry amount for the injections 503-505, and where distribution can take place between the injection 502 and the virtual injection 506. By proceeding in this way, an industry shift between insp2 and subsequent injections is required. .ex. to anticipate or delay an accumulated amount of fuel (the total amount of fuel to be injected can be substantially constant, but if necessary with regard to changes in efficiency, so that the desired work is still carried out) is not specifically allocated between the injections 503-505, without distribution occurs at this stage between the injection 502 and the "virtual" injection 506, respectively.

Once the injection 502 has been performed, the procedure is repeated as above, with a new determination of the injection scheme to regulate the generated nitrogen oxides NO but then with the injection 503 as a separate injection, see Fig. 5B, and injection 504, 505 together constitute a virtual injection during distribution as above.

In Fig. 5A, the virtual injection 506 consists of three injections, but as will be appreciated, the virtual injection 506 may initially comprise more than three injections, such as 10 injections or 100 injections, depending on how many injections are intended to be performed. during the combustion cycle, the procedure being repeated until all the injections have been made.

According to one embodiment, e.g. an MPC (Model Predictive Control) control when controlling according to the invention. An example of an MPC control is shown in Fig. 6, where the reference curve 603 corresponds to the expected development for the generation of nitrogen oxides NO during the combustion cycle. Curve 603 thus represents the evolution of the accumulated generated nitrogen oxides NO which are aspirated during the combustion cycle. This curve can e.g. consists of a realistically achievable (eg lowest or other desired) level for the generated nitrogen oxides NO at the current load and radiating speed during the combustion cycle, and can advantageously be determined in advance, e.g. by applicable calculations and / or feeds on the motor type, whereby this data can be stored in the control system memory as a function of e.g. speed and load. This also means that the combustion does not have to be directed only towards a customary generation of nitrogen oxides NOR, but can also be arranged to be directed towards a expected total development for the amount of generated nitrogen oxides NOR, such as e.g. curve 603 in Fig. 6, each injection being intended to result in a hitherto accumulated amount of nitrogen oxides NO which at the given time amounts to the corresponding point on curve 603. Curve 603 may in one embodiment consist of a curve representing expected generated nitrogen oxides NO at habit point, ie. not an accumulated amount of nitrogen oxides NOR, whereby the generated amount of nitrogen oxides NO can be regulated against this boron value curve instead.

The solid curve 602 up to time k represents the actual generated amount of nitrogen oxides NO up to time k and which has been calculated as above with the aid of actual data from the crank angle dissolved pressure sensor. Curve 601 represents the predicted development for the generated nitrogen oxides NO based on the selected injection profile, and thus constitutes the development for the generation of nitrogen oxides NO that is expected. Dashed injections 605, 606, 607 represent the predicted control signal, i.e. the expected injection profile is applied, and 608, 609 represent already challenging injections.

The predicted injection profile is updated at appropriate intervals, such as e.g. as usual challenge injection or during pagdende injection, to reach the final value which is sought and given by the reference screw 603, and where the next injection is determined based on prevailing conditions in relation to the estimated generation of nitrogen oxides NOR. 537 308 The invention has been exemplified above in a manner in which a pressure sensor 206 is used to determine a pressure in the combustion chamber, and by means of which temperature and nitrogen oxide generation as above can be estimated. An alternative to using pressure sensors can instead be the use of one (or more) other sensors, such as e.g. high-resolution ion current sensors, knock sensors or strain gauges, whereby the pressure in the combustion chamber can be modeled by utilizing sensor signals from such sensors. It is also possible to combine different types of sensors, e.g. to obtain a more accurate estimation of the pressure in the combustion chamber, and / or to use other applicable sensors, where the sensor signals are converted to the corresponding pressure for use in control as above.

The control according to the invention may also comprise, in addition to performing an estimation of a plurality of oral control alternatives based solely on generated nitrogen oxides NOR, also evaluating control alternatives based on other criteria. For example. control can be performed based on a cost function for different control parameters.

For example. In cases where several injection schemes / control alternatives meet the set conditions, other parameters can be used to select which of these is to be used. There may also be other reasons for simultaneously regulating even based on other parameters. For example. Injection schedule, in addition to based on generated nitrogen oxides NOR, can also be partly selected based on one or more of the perspectives pressure change rate, heat loss, exhaust temperature, exhausted work in the combustion chamber, or pressure amplitude during combustion as additional criteria, where such determination can be performed according to any of the parallel patent applications. Specifically, the parallel application "PROCEDURE AND SYSTEM FOR CONTROLLING AN COMBUSTION ENGINE I" (Swedish patent application, application number: 1350506-0) is shown in the 36 537 308 parallel application for a procedure for regulating subsequent combustion based on an estimated maximum pressure change rate.

Furthermore, the parallel application "PROCEDURE AND SYSTEM FOR REGULATING AN COMBUSTION ENGINE II" (Swedish patent application, application number: 1350507-8) shows a procedure for regulating a subsequent part of combustion during a first combustion cycle during said first combustion cycle. subsequent combustion resulting temperature.

Furthermore, the parallel application "PROCEDURE AND SYSTEM FOR REGULATING AN COMBUSTION ENGINE III" (Swedish patent application, application number: 1350509-4) shows a procedure for regulating combustion during a first combustion cycle during a subsequent part of said first combustion cycle with respect to a combustion engine. exhausted work.

Furthermore, the parallel application "PROCEDURE AND SYSTEM FOR REGULATING AN COMBUSTION ENGINE IV" (Swedish patent application, application number: 1350510-2) shows a procedure for regulating combustion during a first combustion cycle during a subsequent part of said first combustion cycle of a heat loss resulting from said combustion.

Furthermore, the parallel application "PROCEDURE AND SYSTEM FOR REGULATING AN COMBUSTION ENGINE V" (Swedish patent application, application number: 1350508-6) shows a procedure for regulating subsequent combustion based on an estimated maximum pressure amplitude. 37 537 308 Furthermore, in the above description, an exemplary method for estimating temperature change during the combustion cycle has been applied. As will be appreciated, other applicable methods for estimating pressure and / or temperature and / or generated nitrogen oxides NO may also be applied to those exemplified in the present specification.

Furthermore, in the above description, only fuel injection has been regulated. Instead of regulating the amount of fuel supplied, the combustion can be arranged to be regulated with the aid of e.g. exhaust valves, in which case injection can be carried out according to a predetermined schedule, but the exhaust valves are used to regulate the pressure in the combustion chamber and thus also the temperature.

Furthermore, the control can be performed with any applicable type of regulator, or e.g. using state models and state feedback (for example, line programming, the LQG method or similar).

The process according to the invention for controlling the internal combustion engine can also be combined with sensor signals from other sensor systems where resolution at the crank angle level is not available, such as e.g. other pressure sensors, NOx sensors, NH3 sensors, PM sensors, oxygen sensors and / or temperature sensors etc., which input signals e.g. can be used as input parameters when estimating e.g. pre-measured pressure / temperature by utilizing data-driven models in whole or in part istdllet for models of the type described above.

Furthermore, the present invention has been exemplified above in connection with vehicles. However, the invention is also applicable to arbitrary vessels / processes where nitric oxide control as above is applicable, such as e.g. water or aircraft with combustion processes as above. It should also be noted that the system can be modified according to various embodiments of the method according to the invention (and vice versa) and that the present invention is not in any way limited to the above-described embodiments of the method according to the invention, but relates to and includes all embodiments the scope of the attached independent requirements. 39

Claims (41)

A method of controlling an internal combustion engine (101), said combustion engine (101) comprising at least one combustion chamber (201) and means (202) for supplying fuel to said combustion chamber (201), said combustion in said combustion chamber (101). 201) takes place in combustion cycles, the process being characterized in that: Determining during a first part of a first combustion cycle a first parameter value representing a quantity for combustion in said combustion chamber, and based on said first parameter value estimating a first mat of nitrogen oxides (NO) resulting from combustion during at least a part of said first combustion cycle, and 2. based on said first mat, regulating combustion during a subsequent part of said first combustion cycle. A method according to claim 1, wherein said estimated first mat constitutes an estimated nitrogen oxide (NOx) content for the exhaust gases resulting from the combustion. A method according to any one of claims 1-2, further comprising: 1. in said control, regulating the combustion against a sense level of the nitrogen oxides generated during said first combustion cycle (1 \ 10x). A method according to any one of claims 1-3, further comprising: 1. in said control, controlling the combustion against a minimization of the nitrogen oxides (NOx) generated during said first combustion cycle. 537 308 A method according to any one of claims 1-4 further comprising: 1. using a first sensor means determining a first parameter value representing a quantity in combustion in said combustion chamber (201), and 2. based on said first parameter value, estimating said first matt on nitrogen oxides (NO) resulting from combustion during said first combustion cycle. The method of claim 5, wherein said first parameter value represents a pressure radiating in said combustion chamber (201). A method according to any preceding claim, further comprising: 1. estimating an expected combustion temperature change during said subsequent part of said first combustion cycle, and estimating the amount of resulting nitrogen oxides (NO) at least in part based on said expected combustion temperature change during said subsequent combustion temperature change. combustion cycle. The method of claim 7, wherein said combustion temperature change in said combustion chamber (201) is estimated at least in part by estimating a heat release during said combustion. A method according to claim 7 or 8, further comprising estimating the amount of available nitrogen gas (N2) and the amount of available oxygen gas (O 2), respectively, at least in part by utilizing an industry quantity for supply to said combustion, wherein the amount of generated nitrogen oxides (NOx) 41 537 308 is estimated. at least in part based on the said available amounts of nitrogen gas and oxygen, respectively. A method according to any one of claims 7-9, wherein an estimated combustion temperature change in said control is estimated at least in part based on an estimated pressure change in said combustion chamber (201). A method according to any one of claims 7-10, further comprising estimating said combustion temperature as a sum of an estimation of a temperature increase caused by combustion relative to a first temperature, and an estimation of said first temperature, wherein said first temperature is a estimated temperature of unburned gas in the said combustion chamber. The method of claim 8, further comprising estimating said heat release by utilizing an industry quantity for supply to said combustion. A method according to any one of the preceding claims, further comprising estimating the amount of nitrogen oxides generated (NO.) At least in part by utilizing a Zeldovich mechanism. A method according to any preceding claim, further comprising estimating the amount of nitrogen oxides generated (NO.) At least in part using one or more of: data driven model, empirical model, physical model. A method according to any one of the preceding claims, further comprising determining At least one control parameter for controlling said subsequent combustion, wherein said control parameter is a control parameter where the estimated amount of nitrogen oxides generated (NO) in the combustion during control according to said control parameter is required to be less than one. first amount of nitrogen oxides generated (N0x). A method according to any one of the preceding claims, further comprising: - in determining a control parameter for controlling said subsequent combustion based on said first matte of nitrogen oxides (NO), determining a control parameter which is expected to result in the desired, or at least half of the desired , work on the said combustion. A method according to any preceding claim, further comprising controlling combustion during said subsequent portion of said first combustion cycle by controlling the amount of fuel for supply to said combustion chamber (201). A method according to any one of the preceding claims, further comprising: - estimating an expected amount of generated nitrogen oxides (NO) for at least two control alternatives for said subsequent combustion by utilizing said first parameter value, and - selecting a control alternative from said plurality of control alternatives for controlling the combustion during said subsequent combustion based on said expected amounts of nitrogen oxides (NOx) generated. The method of claim 18, further comprising: - determining whether any of said control alternatives constitutes a control alternative where the estimated amount generated by 43,537,308 nitrogen oxides (NO) upon control according to said control alternative is less than an initial amount, and - if sA is the case, selecting a control alternative where the estimated amount of generated nitrogen oxides (NO) is less than said first amount. The method of claim 18 or 19, further comprising selecting the control alternative that is expected to result in the least generated amount of nitrogen oxides (NO) during said subsequent combustion. A method according to any one of claims 18-20, wherein said control alternative consists of alternatives for supplying fuel during said subsequent part of said combustion cycle. A method according to any one of claims 18-21, wherein said fuel supplied to said combustion chamber (201) is regulated by controlling fuel injection by means of at least one fuel injector. A method according to any one of claims 18-22, wherein at least one fuel injection is performed during said subsequent part of said combustion cycle, wherein in said regulation the fuel quantity for injection and / or injection length and / or injection pressure and / or time between injections is regulated for said fuel injection. A method according to any one of claims 18-23, wherein at least two fuel injections are performed during said subsequent part of said combustion cycle, said combustion also being regulated after said first of said two fuel injections. 44 537 308 A method according to any one of claims 18-24, wherein in controlling said combustion, at least three fuel injections are performed during said subsequent part of said combustion process, wherein in regulating a first of said at least three injections, remaining injections are treated as a single total injection. A method according to any one of claims 18-25, wherein controlling the combustion during said subsequent part of said first combustion cycle is performed at least in part by controlling injection of fuel into said combustion chamber (201) during an ongoing fuel injection. A method according to any one of claims 18-26, further comprising changing a distribution of fuel quantities between at least two fuel injections when regulating fuel injection to said combustion chamber (201). A method according to any one of claims 18-27, wherein said control is started after a first injection has at least been started, but before fuel injection during said first combustion cycle has been completed. A method according to any preceding claim, further comprising performing a first fuel injection to said combustion chamber (201) during said first portion of said first combustion cycle, and At least a second fuel injection during said subsequent portion of said combustion cycle, wherein said control parameters determined after the said first fuel injection at least has been partially carried out. 537 308 A method according to any preceding claim, further comprising: 1. determining whether the temperature of said combustion during said combustion cycle has reached maximum temperature during said combustion cycle, and 2. interrupting said process when maximum temperature has been reached. A method according to any one of the preceding claims, further comprising, when said first mat of the resulting nitrogen oxides (NO) is estimated for said combustion: 1. interrupt estimating when estimation has been performed up to a point where a maximum temperature during combustion is expected. A method according to any preceding claim, further comprising controlling combustion during said subsequent portion of said first combustion cycle by controlling one or more valves operating at said combustion chamber (201). A method according to any one of the preceding claims, wherein said control is performed for a plurality of consecutive combustion cycles. A method according to any one of the preceding claims, wherein said first parameter representing a quantity on combustion in said combustion chamber (201) is determined At least at habit crank angle, habit tenth of habit crank angle or every hundredth of habit crank angle. A method according to any one of the preceding claims, wherein said first parameter is determined by using one or more of the group: cylinder pressure sensor, knock sensor, strain sensor, speed sensor, ion current sensor. 46 537 308 36. A method according to any one of the preceding claims, wherein said first mat of nitrogen oxides (NO) resulting from combustion during said first combustion cycle consists of a mat of resulting nitrogen monoxide (NO) and / or nitrogen dioxide (NO2). A computer program comprising program code, which when said program code is executed in a computer causes said computer to perform the method according to any one of claims 1- 36. 37. A computer program product comprising a computer readable medium and a computer program according to claim 37, wherein said computer program is included in said computer readable medium. A system for controlling an internal combustion engine (101), said combustion engine (101) comprising at least one combustion chamber (201) and means (202) for supplying fuel to said combustion chamber (201), combustion in said combustion chamber (201). in combustion cycles, the method being characterized in that the system comprises: - means (115) arranged to determine during a first part of a first combustion cycle a first parameter value representing a quantity in combustion in said combustion chamber, and based on said first parameter value estimating a first parameter value. on nitrogen oxides (NO) resulting from combustion during at least a portion of said first combustion cycle, and means (115) arranged to regulate combustion during a subsequent part of said first combustion cycle based on said first mat. A system according to claim 39, characterized in that said internal combustion engine consists of one of the group: vehicle engine, marine engine, industrial engine. 47 537 308 Vehicle (100), characterized in that it comprises a system according to claim 39. 48