WO2014175817A1

WO2014175817A1 - Method and system for control of an internal combustion engine

Info

Publication number: WO2014175817A1
Application number: PCT/SE2014/050491
Authority: WO
Inventors: Ola Stenlåås; Kenan MURIC
Original assignee: Scania Cv Ab
Priority date: 2013-04-25
Filing date: 2014-04-24
Publication date: 2014-10-30
Also published as: SE1350507A1; DE112014001724B4; SE539296C2; BR112015025004A2; DE112014001724T5

Abstract

The present invention pertains to a method for the control of a combustion engine (101), wherein said combustion engine (101) comprises at least one combustion chamber (201) and elements (202) for the supply of fuel to the said combustion chamber (201), where the combustion in the said combustion chamber (201) occurs in combustion cycles. During a first part of a first combustion cycle, with the help of a first sensor element (206), a first parameter value representing a physical quantity for combustion in said combustion chamber (201) is determined, and - based on said first parameter value, the combustion during a subsequent part of said first, combustion cycle is controlled, where during said control of the combustion during said subsequent part of said first combustion cycle, the combustion is controlled with respect to a resulting temperature at said subsequent combustion. The invention also relates to a system and a vehicle.

Description

METHOD AND SYSTEM FOR CONTROL OF AN INTERNAL COMBUSTION ENGINE Field of the invention

The present invention pertains to combustion engines, and in particular to a method for the control of a combustion engine according to the preamble of claim 1. The invention also relates to a system 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 background description below constitutes a background description for the invention, and thus need not necessarily constitute prior art technology.

In connection with increased government interests concerning pollution and air quality, emission standards and regulations regarding emissions from combustion engines have been drafted in many urisdictions.

Such emission regulations often consist of requirements defining acceptable limits for exhaust emissions in vehicles equipped with combustion engines. For example, levels of nitrogen oxides (NO_x) , hydrocarbons (HC) and carbon monoxide (CO) are often regulated. These emission regulations may also e.g. handle the occurrence of particles in exhaust emissions.

In an effort to comply with these emission regulations, the exhausts caused by the combustion of the combustion engine are treated (purified) . By way of example, a so-called catalytic purification process may be used, so that exhaust treatment systems in e.g. vehicles and other vessels usually comprise one or more catalysts and/or other components. For example, the exhaust treatment systems in vehicles with a diesel engine often comprise particulate filters. The occurrence of unwanted compounds in the exhaust flow resulting from the combustion engine is to a large extent caused by the combustion process in the combustion engine's combustion chamber, at least partly depending on the amount of fuel consumed in the combustion. For this reason, and due to that a very large part of the operating economy of primarily heavy goods vehicles is controlled by the amount of fuel consumed, great efforts are also made to make the combustion engine's combustion more efficient in an effort to reduce emissions and fuel consumption.

Summary of the invention

One objective of the present invention is to provide a method to control a combustion engine. This objective is achieved with a method according to claim 1. The present invention pertains to a method for the control of a combustion engine, where said combustion engine comprises at least one combustion chamber and elements for the supply of fuel to said combustion chamber, wherein the combustion in said combustion chamber occurs in combustion cycles.

During a first part of a first combustion cycle, with the help of a first sensor element, a first parameter value is

determined, which represents a physical quantity in connection with combustion in said combustion chamber, and

- based on said first parameter value, the combustion is controlled during the subsequent part of said first combustion cycle, where during said control, the combustion during said subsequent part of said first combustion cycle is controlled with respect to a representation of a resulting temperature at said subsequent combustion, such as the temperature at EVO, i.e. an opening of the exhaust valves, after the combustion during the combustion cycle. As mentioned above, the efficiency of the combustion engine has a great impact on a vehicle's total economy, in particular with respect to heavy goods vehicles. For this reason, it is often desirable that the combustion is controlled in a manner that entails as efficient a combustion as possible.

In addition, the combustion engine's combustion may be controlled with respect to desired exhaust characteristics during the treatment in the subsequent exhaust system. For example, the timing of injection and/or the amount of injected fuel may be controlled in order to impact the course of the combustion and thus the temperature and/or composition of the exhaust stream. For example, in certain cases a higher exhaust temperature may be desirable at the expense of the efficiency of the combustion engine in order for a desired function for one or several components in the after-treatment system to be obtained. It may also be the case that the total efficiency, including the exhaust after-treatment, may be improved also in the event of a deterioration of the combustion engine's efficiency, e.g. due to reduced consumption of reducing agent, e.g. the urea supply, at the expense of an increased fuel supply. In certain situations a deterioration of the total efficiency may also be acceptable, e.g. to achieve a desired condition in the after-treatment system.

The present invention pertains to controlling the combustion process where an ongoing combustion cycle's progress may be controlled during the ongoing combustion to achieve a desired result of the combustion. Specifically, the combustion's progress is controlled with respect to a resulting temperature during the combustion. This resulting temperature may consist of a resulting average temperature for the gas in the

combustion chamber at the end of the combustion cycle. The regulation according to the present invention may be achieved by, during a first part of a combustion cycle, determining a parameter value representing a physical quantity during combustion, e.g. a pressure prevailing in the combustion chamber.

Based on this parameter value, e.g. the prevailing pressure, the combustion is then controlled during a subsequent part of the combustion cycle, so that the combustion is controlled with respect to a temperature for the said combustion process. By proceeding in this manner, the desired exhaust and/or combustion characteristics may be achieved during combustion. For example, it may be desirable for the temperature of the exhausts to achieve a certain temperature when emitted from the engine. The combustion may thus be controlled toward a desired resulting exhaust temperature at the time when the exhaust valves are opened, so that an exhaust stream with a very exact and desired temperature may be achieved. This may e.g. be desirable in order to achieve desired characteristics, such as a desired temperature and/or desired chemical

reactions in exhaust treatment components of the exhaust system.

For example, a relationship between an applicable component in the after-treatment system, e.g. an SCR catalyst, and the temperature of the exhaust stream when emitted from the cylinder may be determined, so that a mapping with respect to the exhaust stream's temperature change from the cylinder to e.g. the SCR catalyst may be carried out, and so that the mapping may be applied in order to determine a desired exhaust temperature resulting during combustion, which is then

expected to result in a desired temperature at e.g. the SCR catalyst. Alternatively, e.g. a table may be used with e.g. ambient temperature, one or several temperatures in the after- treatment system, and a resulting temperature at combustion, so that a reference value at combustion may be determined by way of table lookup.

Alternatively, the combustion cycle may be regulated with respect to the temperature change which the combustion process undergoes during the combustion, i.e. the combustion is controlled based on how the combustion chamber temperature varies during the combustion, i.e. not solely toward a final temperature, and may e.g., to the extent possible, be brought to follow a suitable temperature curve, so that this

temperature variation is controlled by impacting the

combustion during an ongoing combustion cycle, so that a desired temperature variation during the combustion is achieved. The regulation may be controlled toward an

empirically or otherwise determined temperature curve

(temperature track) which is expected to result in some desired characteristic, e.g. with respect to emissions or some other characteristic.

By controlling the temperature variation during the

combustion, the exhaust stream's composition may be controlled in such a way that the occurrence of the different substances normally occurring in the exhaust stream may be impacted in a desired direction, e.g. depending on the desired composition at one or several exhaust treatment components in the exhaust system. By controlling the temperature variation, emissions may also be minimised. The regulation according to the present invention may e.g. be used to minimise unwanted exhaust emissions. By carrying out the control action during an ongoing combustion cycle, the combustion may be impacted to a greater extent, compared to carrying out the control action merely based on previous combustion cycles . During a control action, according to the invention, a representation of a resulting temperature and/or temperature change may be predicted through an estimation for said subsequent part of said first combustion cycle, based on said first parameter value. The subsequent combustion may then be controlled based on said representation of said estimated temperature and/or temperature change. Thus, the temperature development for the future part of the combustion cycle may be predicted through an estimation, where said first parameter value provides for a good estimation, since the estimation is carried out with starting values consisting of actually prevailing circumstances in the combustion chamber after the combustion cycle has been initiated.

According to one embodiment, said first parameter value is determined when the combustion has been initiated in the said first combustion chamber, so that the regulation of combustion during the following part of said first combustion cycle may be carried out based on prevailing conditions in the

combustion chamber after the combustion of fuel has been initiated. Said first parameter value thus constitutes a representation of an actually prevailing relationship for said physical quantity for a point in time/crank angle position when said first combustion cycle has been initiated.

Said temperature/temperature change may e.g. be estimated through estimation of the pressure change occurring in said combustion chamber during said subsequent part of the

combustion cycle.

The regulation of the combustion may also be arranged to be carried out individually for each cylinder, and it is also possible to control a combustion during a subsequent

combustion cycle, based on information from one or several previous combustion processes. This type of control has the advantage that e.g. differences between different cylinders may be detected and offset with individual adjustment of parameters for a specific cylinder, such as the opening time of the injection nozzle, etc.

However, differing control actions for different cylinders may also be desirable, e.g. in order to control certain cylinders toward the fulfilment of a certain criterion, and other cylinders toward some other applicable criterion, and this may also be achieved according to the invention. Further, only one or some of the cylinders may be arranged to be controlled according to the invention, while combustion in the remaining cylinders may be carried out in a customary or other

applicable manner.

The method according to the present invention may e.g. be implemented with the help of one or several FPGA (Field- Programmable Gate Array) circuits, and/or one or several ASIC (application-specific integrated circuit) circuits, or other types of circuits which may handle the desired calculation speed.

Further characteristics of the present invention and

advantages thereof will be described in the detailed

description of example embodiments set out below and in the enclosed drawings.

Brief description of drawings

Fig. 1A shows schematically a vehicle in which the present invention may be used.

Fig. IB shows a control device in the control system for the vehicle shown in Fig. 1A.

Fig. 2 shows the combustion engine in the vehicle shown in

Fig. 1A in more detail. Fig. 3 shows an example embodiment according to the present invention .

Fig. 4 shows an example of an estimated temperature track in a combustion.

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

Fig. 6 shows an example of MPC. Detailed description of embodiments

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

The combustion engine 101 is controlled by the engine's control system via a control device 115. Likewise, the clutch 106, which may consist of e.g. an automatically controlled clutch, as well as the gearbox 103 are controlled by the vehicle's control system with the help of one or more

applicable control devices (not shown) . Naturally, the vehicle's driveline may also be of another type, such as a type with a conventional automatic gearbox, or a type with a manual gearbox, etc.

An output shaft 107 from the gearbox 103 operates the driving wheels 113, 114 in a customary manner via the end gear and driving shafts 104, 105. Fig. 1A shows only one shaft with driving wheels 113, 114, but in a customary manner the vehicle may comprise more than one shaft equipped with driving wheels, or one or more extra shafts, such as one or more support shafts. The vehicle 100 also comprises an exhaust system with an after-treatment system 200 for customary treatment (purification) of exhaust emissions resulting from combustion in the combustion chamber (e.g. cylinders) of the combustion engine 101.

The after-treatment system often comprises some form of catalytic purification process, where one or several catalysts are used to purify the exhausts. Vehicles with diesel engines often also comprise a diesel particulate filter (DPF) in order to catch soot particles formed during combustion of fuel in the combustion engine's combustion chamber. Further, after- treatment systems in vehicles of the type displayed may comprise an oxidation catalyst (Diesel Oxidation Catalyst, DOC) . The oxidation catalyst DOC has several functions, and is normally used primarily in the after-treatment to oxidise remaining hydrocarbons and carbon monoxide in the exhaust stream into carbon dioxide and water. The oxidation catalyst may also e.g. oxidise nitrogen monoxide (NO) into nitrogen dioxide (N0₂) . Also, an after-treatment system may comprise more components than as exemplified above, as well as fewer components. For example, the after-treatment system 200 may comprise an SCR (Selective Catalytic Reduction) catalyst arranged downstream of the particulate filter. SCR catalysts use ammoniac (NH₃) , or a composition from which ammoniac may be generated/formed, as an additive to reduce the amount of nitrogen oxides NO_x in the exhaust stream.

Further, combustion engines in vehicles of the type shown in Fig. 1A are often equipped with controllable injectors, in order to supply the desired amount of fuel at the desired point in time in the combustion cycle, such as at a specific piston position (crank angle degree) in the case of a piston engine, to the combustion engine's combustion chamber.

Fig. 2 shows schematically an example of a fuel injection system for the combustion engine 101 exemplified in Fig. 1A. The fuel injection system consists of a so-called Common Rail system, but the invention is equally applicable in other types of injection systems. Fig. 2 shows only one

cylinder/combustion chamber 201 with a piston 203 active in the cylinder, but the combustion engine 101 consists, in the present example, of a six-cylinder combustion engine, and may generally consist of an engine with any number of

cylinders/combustion chambers, e.g. any number of

cylinders/combustion chambers in the range 1-20 or even more. The combustion engine also comprises at least one respective injector 202 for each combustion chamber (cylinder) 201. Each respective injector is thus used for the injection (supply) of fuel in 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 the respective injectors, which, based on received control signals, e.g. from the control device 115, control the opening/closing of the injectors 202. The control signals for the control of the actuators'

opening/closing of the injectors 202 may be generated by some applicable control device, such as, in this example, by the engine control device 115. The engine control device 115 thus determines the amount of fuel which actually is to be injected at any given time, e.g. based on prevailing operating

conditions in the vehicle 100.

The injection system shown in Fig. 2 thus consists of a so- called Common Rail system, which means that all injectors (and therefore all combustion chambers) are supplied with fuel from a common fuel conduit 204 (Common Rail) , which, with the use of a fuel pump 205, is filled with fuel from a fuel tank (not shown) at the same time as the fuel in the conduit 204, also with the help of the fuel pump 205, is pressurised to a certain pressure. The highly pressurised fuel in the common conduit 204 is then injected into the combustion engine's 101 combustion chamber 201 when the respective injector 202 is opened. Several openings/closings of a specific injector may be carried out during one and the same combustion cycle, so that several injections may thus be carried out during the combustion of one combustion cycle. Further, each combustion chamber is equipped with a respective pressure sensor 206, for sending of signals regarding a prevailing pressure in the combustion chamber to e.g. the control device 115. The pressure sensor may e.g. be piezo-based and should be fast enough to be able to send crank angle resolved pressure signals, e.g. at every 10th, every 5th or every crank angle degree or with another suitable interval, e.g. more

frequently .

With the help of a system of the type shown in Fig. 2, the combustion during a combustion cycle in a combustion chamber may to as large extent be controlled, e.g. with the use of multiple injections, where the times and/or duration for the respective injections may be controlled, and where data from e.g. the pressure sensors 206 may be taken into consideration in connection with this control action. According to the present invention, e.g. times and/or durations of injections and/or injected fuel amounts during ongoing combustion may be adapted, based on data from the ongoing combustion with the objective of controlling the combustion with respect to a temperature which is predominant at combustion and/or a resulting temperature. Fig. 3 shows an example method 300, according to the present invention, where the method according to the present example is arranged to be carried out by the engine control device 115 shown in Figs. 1A-B . In general, control systems in modern vehicles consist of a communication bus system consisting of one or more

communications buses to connect a number of electronic control devices (ECUs) , such as the control device, or controller, 115, and various components arranged on the vehicle. According to prior art, such a control system may comprise a large number of control devices, and the responsibility for a specific function may be distributed among more than one control device.

For the sake of simplicity, Figs. 1A-B show only the control device 115, in which the present invention is implemented in the embodiment displayed. The invention may, however, also be implemented in a control device dedicated to the present invention, or wholly or partly in one or several other control devices already existing in the vehicle. Considering the speed at which calculations according to the present invention are carried out, the invention may be arranged to be implemented in a control device which is especially adapted for real time calculations of the type described below. The implementation of the present invention has showed that e.g. ASIC and FPGA solutions are suitable for and cope well with calculations according to the present invention.

The function of the control device 115 (or the control device (s) at which the present invention is implemented), according to the present invention, may, apart from depending on sensor signals from the pressure sensor 202, e.g. depend on signals from other control devices or sensors. Generally, control devices of the type displayed are normally arranged to receive sensor signals from different parts of the vehicle, as well as from different control devices arranged on the vehicle . Control is often controlled by programmed instructions . These programmed instructions typically consist of a computer program, which, when it is executed in a computer or a control device, causes the computer/control device to carry out the desired control action, as a method step in the process according to the present invention.

The computer program usually consists of a computer program product, where the computer program product comprises an applicable storage medium 121 (see Fig. IB), with the computer program stored on said storage medium 121. Said digital storage medium 121 may e.g. consist of any from the following group: ROM (Read-Only Memory), PROM (Programmable Read-Only Memory) , EPROM (Erasable PROM) , Flash, EEPROM (Electrically Erasable PROM), a hard disk unit, etc., and may be set up in or in combination with the control device, where the computer program is executed by the control device. By changing the computer program's instructions, the vehicle's behaviour may thus be adjusted in a specific situation.

An example control device (control device 115) is shown schematically in Fig. IB, and the control device in turn may comprise a calculation unit 120, which may consist of e.g. a suitable type of processor or microcomputer, e.g. a circuit for digital signal processing (Digital Signal Processor, DSP) , one or several FPGA (Field-Programmable Gate Array) circuits or one or several circuits with a predetermined specific function (Application Specific Integrated Circuit, ASIC) . The calculation unit 120 is connected to a memory unit 121, which provides the calculation unit 120 with e.g. the stored program code and/or the stored data which the calculation unit 120 needs in order to be able to carry out calculations. The calculation unit 120 is also set up to store interim or final results of calculations in the memory unit 121. Further, the control device is equipped with devices 122, 123, 124, 125 for receipt and sending of input and output signals. These input and output signals may contain waveforms, pulses, or other attributes, which may be detected as information for processing by the calculation unit 120 by the devices 122, 125 for the receipt of input signals. The devices 123, 124 for sending output signals are arranged to convert the calculation result from the calculation unit 120 into output signals for transfer to other parts of the vehicle's control system and/or the component (s) for which the signals are intended. Each one of the connections to the devices for receipt and sending of input and output signals may consist of one or several of the following; a cable; a data bus, such as a CAN (Controller Area Network) bus, a MOST (Media Oriented Systems Transport) bus, or any other bus configuration; or of a wireless connection.

Reverting to the method 300 shown in Fig. 3, the method begins at step 301, where it is determined whether the control according to the invention of the combustion process should be carried out. The control according to the invention may e.g. be arranged to be carried out continuously as soon as the combustion engine 101 is started. Alternatively, the control action may be arranged to be carried out e.g. as long as the combustion engine's combustion is not to be controlled according to some other criterion. For example, there may be situations where it is desirable that the control action is carried out based on factors other than primarily the

combustion's temperature. According to one embodiment, simultaneous control of the combustion is carried out with respect to the combustion's temperature and at least one additional control parameter. For example, a weighing up may be carried out, where the control parameters' prioritisation on fulfilment of a desired control result may e.g. be arranged to be controlled according to some suitable cost function. The method according to the present invention thus consists of a method for the control of the combustion engine 101 while the combustion takes place in said combustion chamber 201 in combustion cycles. According to prior art, the term combustion cycle is defined as the steps comprised in a combustion in a combustion engine, e.g. a two-stroke engine's two strokes and a four-stroke engine's four strokes. The term also includes cycles where no fuel is actually injected, but where the combustion engine is still operated with a certain engine speed, such as with the vehicle's driving wheels via the driveline in e.g. dragging. That is to say, even if no injection of fuel is carried out, a combustion cycle is still completed for e.g. every two revolutions (for four-stroke engines), or e.g. every revolution (two-stroke engines), which the combustion engine's output shaft rotates. The same applies to other types of combustion engines.

In step 302, it is determined whether a combustion cycle has been or will be started, and where this is the case, the method continues to step 303 while a parameter i representing an injection number is set equal to one.

In step 303, an injection schedule is determined which is expected to result in a desired temperature during the combustion, e.g. an injection schedule which is expected to result in a desired end temperature or which is expected to result in a desired temperature track during the combustion of the combustion cycle.

Generally, the supply of fuel, both with respect to quantity and manner of supply, i.e. the one or several fuel injections that are to be carried out during the combustion cycle, is normally defined in advance, e.g. depending on the work

(torque) which the combustion engine must carry out during the combustion cycle, since no change of the determined injection schedule is carried out during an ongoing combustion cycle according to prior art. Predetermined injection schedules may e.g. exist in tables in the vehicle's control system for a large number of operating modes, such as different engine speeds, different requested work, different combustion air pressures, etc., where tabulated data may e.g. be prepared by way of applicable tests/measurements during e.g. the

development of the combustion engine and/or vehicle, so that the applicable injection schedule may be selected based on prevailing conditions, and where the injection schedule may be selected e.g. based on a wish regarding how the temperature in the combustion chamber should change.

These injection schedules may consist of the number of injections and characteristics in the form of e.g. timing (crank angle position) at the start of the injection, the duration of the injection, the injection pressure, etc., and thus may be stored for a large number of operating modes in the vehicle's control system, and e.g. be calculated/measured with the objective of resulting in a certain exhaust

temperature .

According to one embodiment of the invention, an injection schedule is determined with applicable calculations before the combustion is started, e.g. as set out below, where e.g. the requested achieved work, the requested exhaust temperature, the requested emissions (e.g. high/low NO_x share) may

constitute parameters in the calculations, as well as e.g. the requested end temperature for the exhausts, such as according to one embodiment of the invention. According to the present embodiment, such a predetermined injection schedule is applied in step 303, where this predetermined injection schedule is selected based on

prevailing conditions and the work requested from the

combustion engine, e.g. by way of table lookup. According to one embodiment, a desired exhaust temperature may also constitute a parameter in the selection of an injection schedule, so that different injection schedules may be defined where different temperature developments are expected at the combustion, while e.g. the same work on the combustion engine's output shaft is carried out. According to one embodiment, a desired temperature need not be included in the selection of an injection schedule in step 303, but the temperature parameter may be arranged to be applied only during the control action after a first injection, or a first part of an injection, has been completed. According to one embodiment, the injection schedule is determined wholly according to e.g. the calculations displayed below, where e.g. different injection schedules defined in advance may be compared with each other in step 303 in order to determine a most preferred injection schedule, thus already before a first fuel injection is carried out, but in the calculation example exemplified below, the calculations are, however, applied only after an injection has been started in the combustion cycle. Since specific assumed conditions probably result in the same preferred injection schedule each time, it may be advantageous to select an injection schedule through some type of lookup before a combustion cycle, and thus to reduce the calculation load, so that calculation as set out below is thus carried out only after the injection has started. In addition to the example below of how the injection schedule may be determined, other models with a similar function may alternatively be applied. The target temperature, T_targetEvo_f which is desired for the exhausts when the exhaust valves are opened and the exhausts are brought out into the exhaust system, and which may control the selection of an injection schedule, may be determined in a suitable manner. As mentioned above, e.g. a relationship between the temperature of the exhaust stream at some

applicable component in the after-treatment system and the temperature of the exhaust stream at the outlet from the cylinder may be determined, so that T_targetEvo may be determined based on a certain desired temperature in the after-treatment system. Alternatively, e.g. T_targ_etEvo may be controlled based on signals from one or several temperature sensors in the after- treatment system. T_targetEVo may also e.g. be arranged to be controlled by empirical data, where measurements may have been made in advance and e.g. exhaust emissions or other parameters have been measured, and where advantageous combustion chamber temperatures may have been measured and subsequently fed into the vehicle's control system, so that reference values at combustion may be determined by table lookup or in another suitable manner. According to the below, according to one embodiment, not only a final temperature T_targetEvo is

determined, but a preferred temperature track may be

determined, e.g. based on empirical data, and where the control action is subsequently carried out in relation to this determined temperature track.

According to the present embodiment, in step 303, a predefined injection schedule at the start of the combustion cycle is thus determined, where the control action according to the invention is carried out only after the fuel injection has been started during a combustion cycle, such as only after the at least one injection has been completed during the combustion cycle, or after one injection has at least been started .

Fuel injection is thus normally carried out according to a predetermined schedule, where several injections may be arranged to be carried out during one and the same combustion cycle. This entails that the injections may be relatively short. For example, there are injection systems with 5-10 fuel injections/combustion, but the number of fuel injections during a combustion cycle may also be significantly greater, e.g. in the range of 100 fuel injections. The number of possible injections is controlled by the speed of the elements with which the injection is carried out, i.e. in the case of a Common Rail system how fast the injectors may be opened and closed. According to the present example, at least three fuel

injections inspi are carried out during one and the same combustion cycle, but, as mentioned and as set out below, a greater number of injections may be arranged to be carried out, as well as only one or two. The injection schedule is thus, in the present example, determined in advance in order to obtain a certain exhaust temperature, or only based on the desired work achieved. A first injection inspi is then carried out, and in step 304 it is determined whether said first injection inspi has been carried out, and, if so, the method continues to step 305 where it is determined whether all injections i have been carried out. Since this is not yet the case in the present example, the method continues to step 306 while i is

incremented by one for the next injection. In step 306, the prevailing pressure in the combustion chamber is determined with the use of the pressure sensor 206. Further, with the use of the pressure sensor 206, the prevailing pressure in the combustion chamber may be determined substantially

continuously, such as with applicable intervals, e.g. every 0.1-10 crank angle degrees. The combustion process may generally be described with the pressure change in the combustion chamber, which the

combustion gives rise to. The pressure change during a

combustion cycle may be represented by a pressure track, i.e. a representation of how the pressure in the combustion chamber varies during the combustion. As long as the combustion continues as expected, the pressure in the combustion chamber will be equal to the initially expected or estimated pressure. According to the below, the temperature is directly related to the pressure in the combustion chamber, which means that as soon as the pressure deviates from the estimated pressure, the temperature will also deviate from the expected/estimated temperature. Additionally, the combustion during the

subsequent part of the combustion cycle and thus the

temperature development will be impacted. In step 306, the pressure p_fei in said combustion chamber 201 is determined for a prevailing crank angle degree Θχ (see Fig. 4) with the help of the said pressure sensor 206 and in step 307 an expected resulting exhaust temperature during and/or at the end of the combustion cycle's combustion is estimated, according to the above, e.g. an estimation of the exhaust temperature at the time of the exhaust valve opening T_Evo

(Exhaust Valve Opening) . This may be carried out with the help of applicable calculations, and one way of carrying out this calculation is exemplified below. Alternatively, other models with similar functions may be applied. The expected resulting exhaust temperature at the time of the exhaust valve opening, after the combustion cycle's

combustion, may, according to one embodiment be estimated as follows in step 307.. As will be obvious, the temperature track for the entire combustion, and not only the final temperature, may be estimated according to the method

displayed. The combustion may, as is known to a person skilled in the art, be modelled according to the equation (1) : dQ = K_calibrate (Q_fuel - Q) (1) , where K_caljbrale is used to calibrate the model. K_calibrate consists of a constant which is usually in the range of 0-1, but may also be arranged to assume other values, and which is

determined individually, cylinder by cylinder, or for a certain engine or engine type, and depends in particular on the design of the injector nozzles (spreaders) . dQ may also be modelled in another suitable manner, e.g. by also including other parameters, e.g. turbulence at fuel supply, where this may be modelled in an applicable manner.

Qfuei consists of the energy value for injected fuel amount, Q consists of the amount of energy burned. The combustion dQ is thus proportionate to the injected fuel amount minus the hitherto consumed fuel amount. The combustion dQ may,

alternatively, be modelled with the use of another applicable model, where e.g. regard may be had also to other parameters. For example, the combustion may also constitute a function which depends on a model of turbulence at the supply of air/fuel, which may impact the combustion to different

extents, depending on the amount of air/fuel supplied. Regarding the fuel injections, these may e.g. be modelled as a sum of step functions:

The fuel flow measured as the supplied mass m at an injection k, i.e. how the fuel enters into the combustion chamber during the time window u when the injection is carried out, expressed as the duration of the crank angle degree Θ interval during which the injector is open, may be modelled for a specific injection k as:

where m constitutes the injected fuel amount, and f (m) e.g. depends on the injection pressure, etc. f (m) may e.g. be measured or estimated in advance.

The energy value Qm_y for the fuel, such as diesel or petrol, is generally specified, so that such a general specification may be used. The energy value may also be specifically provided by e.g. the fuel manufacturer, or be approximated for e.g. a country or a region. The energy value may also be arranged to be estimated by the vehicle's control system. With the energy value the equation (1) may be resolved and the heat release may be determined as the combustion progresses.

Further, through the use of a predictive heat release

equation, the pressure change in the combustion chamber may be estimated as e.g.:

(4)

, where Φ constitutes the crank angle degree, i.e. the

pressure change is expressed in crank angle degrees, which entails an elimination of the combustion engine's engine speed dependency during calculations, γ constitutes a parameter which may be estimated in advance, set at a fixed value or calculated during ongoing combustion, γ is generally the heat

capacity ratio, i.e. γ— , where C_p and/or C_v are generally available and tabulated for different molecules, and since the combustion chemistry is known, these tabulated values may be used together with the combustion chemistry in order to calculate each molecule's (e.g. water, nitrogen, oxygen, etc.) impact on e.g. the total C value, so that this may be determined for the calculations above with a good accuracy, in advance or during e.g. ongoing combustion.

Alternatively, C_p and/or C_v may be approximated in a suitable manner. Integration of equation (4) entails the following result : f C (dQ γ dV ty - 1\

P = Pinmai +J dp = p_initial —v—J [—) άΦ (5)

P_MUM constitutes an initial pressure, which, prior to the start of the compression, may e.g. constitute the ambient pressure for combustion engines without a turbo, or a

prevailing combustion air pressure for an engine with a turbo. When the estimation is carried out at a later point in time during the combustion cycle, p_inUial may constitute the then prevailing pressure, as determined by the pressure sensor 206. Thus the pressure in the combustion chamber may be estimated for the entire combustion, where the estimation after each injection, or the next estimation after a certain time has lapsed, will result in an increasingly high accuracy in the estimation, since the actual pressure change during an

increasing part of the combustion cycle will be known.

With the help of the pressure estimated with equation (5) , a corresponding estimated average temperature T_{es t} for the gas in the combustion chamber, for e.g. EVO or for the entire

combustion, may then be calculated with the help of the estimated pressure at EVO and the general gas law:

The volume V , i.e. the combustion chamber's volume, which changes continuously with the piston movement, may be

tabulated in the vehicle's control system or be calculated in an applicable manner, and is crank angle dependent due to the piston movement.

The amount of substance n, i.e. the amount of gas substance in the combustion chamber, will change over time as the

combustion progresses. The amount of substance changes as a result of the chemical reactions occurring during the

combustion. This change is, however, normally only one or a few per cent, so that according to one embodiment the amount of substance n may be assumed to constitute the amount of substance before the combustion.

When the change of the amount of substance during the

combustion is modelled, this may e.g. be modelled as:

(A, m _uei ) ( 7 ;

The amount of substance n will during the course of the stroke time transition from a substance amount prevailing before the combustion n_{before comb} to a substance amount n_{all comb} when all the fuel injected during the combustion cycle has been burned, λ constitutes the fuel/air ratio, and Q_total specifies the total fuel energy which is supplied to the combustion during the combustion cycle. m_fuel constitutes the supplied amount of fuel and Q_now constitutes the amount of energy which has been burned to date, and is determined based on equation (4) and/or with the help of the pressure sensor's signal and diagnostic heat release according to equation (8) :

άθ γ-1^Ράθ γ - 1 άθ ^}

With the help of the above equations, the entire temperature track for the combustion from the first injection to EVO may thus be predicted through estimation by calculating equation (6) for the entire combustion with a certain applicable resolution, such as crank angle degree or a tenth, hundredth, thousandth of a crank angle degree, etc., thereof, i.e. the temperature change over the entire combustion process. This estimated temperature track may e.g. look like the temperature track Tei_est in Fig. 4, where the expected temperature

development and the target temperature T_targetEvo are also shown. Obviously, the temperature track may, however, assume

basically any appearance, depending on the amount of fuel which is injected and the timing of the injection.

In relation to control of the exhaust temperature, the

temperature at EVO after combustion (alternatively, the entire temperature track as set out above) is thus estimated in step 306. The first injection will thus give rise to a combustion, and thus a heat release and a pressure increase. If the combustion should progress exactly as estimated, this

temperature would be equal to the initially expected temperature, i.e. T_eiEvo would consist of T_targetEvo, but as soon as the pressure at Θι, and therefore the temperature Τ_θι, see Fig. 4, deviate from the estimated pressure, the estimated TeiE o_/ as well as the entire new estimated temperature track Teiest will deviate from the expected/desired temperature

TtargetEvo_? according to the selected injection schedule.

The actual temperature track will also very probably differ from the predicted temperature track during the course of the combustion because of heat losses, deviations from the modelled combustion, etc.

It is for this reason the control of the combustion according to the invention is carried out, and, according to the present invention, deviations from the predicted temperature track after the first injection inspi has been completed, are compensated. Based on the determined deviation between how the combustion should have occurred and how it actually occurs, a regulator may be used, which controls the subsequent

combustion, e.g. based on the deviation, where the size and of the nature of this deviation may be taken into consideration. The pressure p_fei determined in step 306, which corresponds to the temperature T_fei in Fig. 4, is thus used in step 306 as I according to the above, in order to estimate T _θιενο with data obtained during the combustion. In other words, with the measured pressure p_fei , the cylinder temperature T eiEvo may be calculated according to equation (6) .

Thus, in step 307, a more probable final temperature T_EVo may be estimated with the help of the above equations. This estimated temperature is then used in step 308 in order to control a subsequent fuel injection based on the estimated temperature (pressure) . With at least one second, but in the present example at least totally three injections (during the combustion cycle) , the combustion may be controlled toward a desired final

temperature T_targetEvo through control of subsequent injections. When the first injection is completed, in the present example, at least two additional injections thus remain, which are adapted during the control action.

A first example of how the control action may be carried out is to distribute the duration (continuance) , and thus the injected fuel, amount between these injections and/or to change the injection timing for one or several consecutive injections. During this control action, the control action is carried out, provided that the requested work is still

achieved, i.e. the combustion cycle continues to generate a requested torque on the output shaft of the combustion engine. The distribution between the second and the third injection, respectively, may be based on whether the estimated

temperature value at EVO exceeds or falls short of the

reference value for the temperature. This control action may be adapted in any manner, but may e.g. be implemented in the form of a proportional regulator which is used, e.g. to determine the size of the amount to be displaced between fuel injections, which e.g. may be expressed as an increase/reduction Au of the period during which injection is ongoing in the respective injection process.

During this control action, the total injected amount of fuel may also change, e.g. because the requested work must still be carried out, but where an adjustment of the fuel amount is required in order to compensate for changes in efficiency. In step 308, a control action of the duration for the two consecutive injections insp₂ and insp₃, respectively, may thus be carried out, where in the present example a constant K, which may be determined in some applicable manner and

multiplied by the difference e between the estimated target temperature (target pressure) and the desired target

temperature (target pressure) is used, in order to determine a change of the duration for the injection insp₂, where in the present example a corresponding change is carried out for insp₃, see equations (8) and (9) .

&U_duration inj 2 = K*e (9) ^^■duration inj 3 — ~&^uduration in/ 2 (10)

, where e constitutes the deviation from the reference value. Further, a corresponding control action may, alternatively or additionally, be carried out for the injection time, where e.g. the start of the injection may be moved forward or postponed. Instead of proportional control, customary PI or

PID control may be used. The method then reverts to step 304, where the injection i is carried out according to the new injection schedule. When this i=2 injection has been

completed, step 305 again determines whether all the

injections have been completed. Since this is not yet the case, i is incremented by one for the next injection, where the pressure in the combustion chamber is determined again (now as p_fQ2 after insp i=2) with the use of a pressure sensor 206, so that a new estimation of T_Evo may be carried out following an injection insp₂ in order to, where needed, adapt insp₃, still with consideration for carrying out desired work. The estimation is carried out as set out above, with the difference that the initial value p_Mia, has been altered to Ρ_ίθ2 because of the combustion which the first injection gave rise to. When all injections have been completed, the method reverts from step 305 to step 301 for control of a subsequent combustion cycle.

The control may also be such that the combustion is controlled toward a desired temperature/desired temperature curve, but where two or more combustion cycles are needed before the desired result is achieved, still however with a control action as set out above.

The control, according to the invention, may also comprise to carry out an estimation of several possible control

alternatives, where the control action is then carried out according to one applicable measure out of said several possible measures, e.g. based on a cost function.

The present invention thus provides a method to, based on a first parameter value determined after a first part of the combustion has been completed, control a subsequent part of the combustion during one and the same combustion cycle based on the first parameter value, where the combustion is

controlled with respect to a temperature for the combustion process, such as a desired final temperature as set out above. Further, at the determination in step 308, an expected

temperature development may be estimated for several different alternative injection schedules for the remaining injections, so that the injection schedule resulting in the most

advantageous temperature development may be selected when the next injection is carried out. 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 inspi has been completed, as long as additional injections are to be carried out. According to the above described method, the injection schedule at the start of the combustion cycle has been

determined based on tabulated values, but, according to one embodiment, the injection strategy may already before the fuel injection starts be determined in the manner described above, so that also the first injection is thus carried out according to an injection schedule determined as set out above, e.g. by carrying out calculations for several injection schedules and selecting the one that seems the most advantageous. Further, the control has hitherto been described in a manner where the characteristics for a subsequent injection are determined based on prevailing conditions in the combustion chamber after the previous injection. The control may, however, also be arranged to be carried out continuously, where pressure determinations may be carried out with the help of the pressure sensor also during ongoing injection, and where the injection schedule may be calculated and corrected all the way, until the next injection is initiated.

Alternatively, even the ongoing injection may be impacted by calculated changes in the injection schedule, also in the cases where several shorter injections are carried out. The injection may also consist of one single, longer injection, where changes to the ongoing injection may be made

continuously, e.g. by way of so-called rate shaping, e.g. by changing the opening area of the injection nozzle and/or the pressure with which the fuel is injected, based on estimations and measured pressure values during the injection. Further, fuel supply during the combustion may comprise only two fuel injections, where e.g. only the second or both injections are controlled e.g. with the help of rate shaping. Rate shaping may also be applied in the event three or more injections are carried out. Further, the invention has been exemplified above with an example where three injections are carried out during a combustion cycle. Naturally, more injections may be carried out during a combustion cycle. Since several fuel injections entail that several durations should be changed over time, at the same time as achieved work should be maintained, the calculations may become more extensive. For example, a very great number of injections may be arranged to be carried out during one and the same combustion cycle, such as ten, or even hundred or so injections.

In such situations there may be several equivalent injection strategies, which thus result in substantially the same result. This introduces an unwanted complexity in the

calculations .

According to one embodiment, a control is applied which is equivalent to the above control. This is achieved by treating the injection nearest in time as a separate injection and subsequent fuel injections as one single additional "virtual" injection. This is exemplified in Fig. 5A, where the injection 501 corresponds to inspi, as set out above, the injection 502 corresponds to insp₂, as set out above, and where the remaining injections 503-505 are treated as one single virtual injection 506, i.e. the injection 506 is treated as one injection with a fuel amount substantially corresponding to the total fuel amount for the injections 503-505, and where a distribution may be made between the injection 502 and the virtual

injection 506. By proceeding in this manner, the shifting which occurs between insp₂ and subsequent injections does not need to be distributed specifically between the injections 503-505, but the distribution at this stage is made between the injection 502 and the "virtual" injection 506,

respectively . Once the injection 502 has been completed, the method is repeated exactly as above, with a new determination of an injection schedule, in order to control the temperature, but with the injection 503 as a separate injection, see Fig. 5B, and the injections 504, 505 jointly constitute one virtual injection with a distribution as set out above.

In Fig. 5A the virtual injection 506 is constituted by three injections, but as is obvious, the virtual injection 506 may comprise, from the beginning, more than three injections, such as tens of injections or hundreds of injections, depending on how many injections that are planned to be carried out during the combustion cycle, so that the method is repeated until all the injections have been completed.

Further, fuel supply during the combustion may comprise only two fuel injections, where the controlled injection is controlled with e.g. the help of rate shaping. Rate shaping may also be applied in the event three or more injections are carried out. It may also be the case that one single injection is carried out during a combustion cycle, where the parameters for this injection change during the ongoing injection by "rate shaping" based on new estimations as the combustion progresses, i.e., e.g. the injection pressure and/or duration of the injection may be controlled during an ongoing

inj ection . Hitherto the control has been described with the objective of obtaining a desired exhaust temperature T_Evo- This may e.g. be the case when it is desirable that a certain temperature be achieved/maintained in one or several after-treatment

components. Temperature control of after-treatment components as such constitutes prior art, and is not the subject of the present invention, but the present invention constitutes a means to improve temperature control. For example, the control may relate to a control of exhaust temperature in order to e.g. obtain a desired SCR temperature, DPF temperature or DOC temperature. The temperature control may also e.g. be used to manage problems related to quickly increasing temperature in e.g. an SCR catalyst or DOC/DPF, with those security and system risks that a quickly rising temperature may entail. In such situations, the combustion may be controlled toward a low T_E O with the objective of reducing the temperature in the a ter-treatment system. The control may also be intended for another type of control of e.g. a DOC catalyst, a T C

catalyst, or a particle reduction system such as a PMFC or a DPF system.

The control, according to the invention, of the combustion's temperature may, however, also be used for emission control, i.e. to control the composition which the resulting exhaust stream will have.

As mentioned above, in the case of the exhaust temperature control, the temperature estimation at EVO is the most important, but in relation to control relating to exhaust emissions, instead the entire temperature track (temperature change curve) which the combustion undergoes is relevant, so that control occurs with the objective of, to the extent possible, obtaining a desired temperature change curve during the combustion. In this case, e.g. computer-driven ("black box") models may be used as a representation of emissions in relation to temperature, so that the temperature track may be controlled to impact the occurrence/presence of one or several substances at combustion. In these computer-driven models the expected emissions may also depend on "global" parameters, e.g. EGR reversal, lambda value, suction pressure, ambient temperature, etc. Alternatively, physical models may be applied. Generally, for certain substances physical models may be preferable/available, while for other substances computer- driven models may be required in the absence of applicable, physical models. The combustion may e.g. be controlled with respect to a fraction and/or concentration for one or several exhaust components, such as HC, CO, N0_X, NO, N0₂, PM.

It is also possible to use e.g. MPC (Model Predictive Control) in the control, according to the invention.

One example of MPC is shown in Fig. 6, where the reference curve 603 corresponds to the expected temperature development during a combustion cycle. The curve 603 thus represents the temperature development which is sought during the combustion cycle, where the combustion may either be controlled only toward a final value or continuously toward the curve 603. The solid curve 602 up to the time k represents the actual development of the temperature until the time k and which has been calculated, as set out above, with the help of actual data from the crank angle resolved pressure transmitter. The curve 601 represents the predicted temperature development based on the selected injection profile, and thus constitutes the temperature development which is expected. Dashed

injections 605, 606, 607 represent the predicted control signal, i.e. the injection profile which is expected to be applied, and 608, 609 represent already completed injections. The predicted injection profile is updated with applicable intervals, e.g. after each completed injection, in order to reach the final value sought and which is given by the reference curve 603, and where the next injection is

determined based on prevailing conditions in relation to the estimated heat loss development. Thus, the present invention provides a method which allows for a very good control of a combustion process, and which adapts the combustion during ongoing combustion, in order to achieve a combustion which, to a greater extent, is consistent with the desired combustion in order to obtain a desired exhaust temperature and/or a desired emission control.

Further, as set out above, the combustion gas temperature is estimated for several different alternative injection

schedules for the remaining injections, so that the injection schedule resulting in the most advantageous temperature may be selected when the next injection is carried out. In cases where several injection schedules/control alternatives fulfil the applicable conditions, other parameters may be used to select which of these are to be used. There may also be other reasons for simultaneously effecting control also based on other parameters. For example, injection schedules may also be partly selected based on one or several of the perspectives pressure amplitude, heat loss, pressure change rate, work achieved in the combustion chamber, or nitrogen oxides generated during the combustion as an additional criterion, in addition to being selected based on temperature, where such determination may be carried out according to any of the parallel patent applications specified below.

Specifically, in the parallel application "METHOD AND SYSTEM FOR CONTROL OF A COMBUSTION ENGINE V", a method is displayed in order to, based on an estimated maximum pressure amplitude, control subseguent combustion.

Additionally, the parallel application "METHOD AND SYSTEM FOR CONTROL OF A COMBUSTION ENGINE I" (Swedish patent application, application number: 1350506-0) shows a method to, based on an estimated maximum pressure change rate, control subsequent combustion .

Further, the parallel application "METHOD AND SYSTEM FOR CONTROL OF A COMBUSTION ENGINE III" shows a method to, during a first combustion cycle, control combustion during a

subsequent part of said first combustion cycle with respect to work achieved during the combustion.

Further, the parallel application "METHOD AND SYSTEM FOR CONTROL OF A COMBUSTION ENGINE IV" shows a method to, during a first combustion cycle, control combustion during a subsequent part of said first combustion cycle with respect to a

representation of a heat loss resulting during said

combustion .

Further, the parallel application "METHOD AND SYSTEM FOR CONTROL OF A COMBUSTION ENGINE VI" shows a method to, during a first combustion cycle, estimate a first measure of nitrogen oxides resulting at combustion during said first combustion cycle, and based on said first measure, to control the combustion during a subsequent part of said first combustion cycle.

The invention has been exemplified above in a manner where a pressure sensor 206 is used to determine a pressure in the combustion chamber, and with which pressure a temperature may then be estimated. As an alternative to using pressure sensors, instead one (or several) other sensors may be used, e.g. high-resolution ion current sensors, knock sensors or strain gauges, where the pressure in the combustion engine may be modelled with the use of sensor signals from such sensors . It is also possible to combine different types of sensors, e.g. in order to obtain a more reliable estimation of the pressure in the combustion chamber, and/or to use other applicable sensors, where the sensor signals are converted into corresponding pressures for use in temperature control as set out above.

Further, in the above description, only the fuel injection has been adjusted. Instead of controlling the amount of fuel supplied, the combustion chamber temperature may be arranged to be controlled with the help of e.g. exhaust valves, so that injection may be carried out according to a predetermined schedule, but where the exhaust valves are used to control the pressure in the combustion chamber and thus also the

temperature .

Further, control may be carried out with some applicable type of regulator, or e.g. with the help of state models and state feedback (e.g. linear programming, the LQG method or similar) . The method, according to the invention, for the control of the combustion engine may also be combined with sensor signals from other sensor systems where the resolution of the crank angle level is not available, e.g. another pressure

transmitter, NO_x sensors, H₃ sensors, PM sensors, oxygen sensors and/or temperature transmitters, etc., the input signals of which may e.g. be used as input parameters in the estimation of e.g. the expected pressure/temperature with the use of computer-driven models.

Additionally, the present invention has been exemplified above in relation to vehicles. The invention is, however, also applicable to any vessels/processes where temperature control, as set out above, is applicable, e.g. watercrafts or aircrafts with combustion processes as per the above.

It should also be noted that the system may be modified according to various embodiments of the method according to the invention (and vice versa) and that the present invention is in no way limited to the above described embodiments of the method according to the invention, but pertains to and comprises all embodiments in the scope of the enclosed independent claims.

Claims

Method for the control of a combustion engine (101) , wherein said combustion engine (101) comprises at least one combustion chamber (201) and elements (202) for the supply of fuel to said combustion chamber (201), wherein combustion in said combustion chamber (201) occurs in combustion cycles, wherein the method is characterised in that:

- during a first part of a first combustion cycle, with the help of a first sensor element (206) , a first parameter value representing a physical quantity for combustion in said combustion chamber (201) is

determined, and

- based on said first parameter value, the combustion during a subsequent part of said first combustion cycle is controlled, so that at said control the combustion during said subsequent part of said first combustion cycle is controlled with respect to a resulting

temperature at said subsequent combustion.

Method according to claim 1, further comprising:

- based on said first parameter value, estimating a representation of a temperature resulting at combustion ( Ttarget_Evo ) and/or temperature change during said

subsequent part of said first combustion cycle, after said first part of said first combustion cycle, and

- based on said estimated resulting temperature

( TtargetEvo ) and/or temperature change, controlling the combustion during said subsequent part of said first combustion cycle. 3. Method according to any of the previous claims, also

comprising : - determining said first parameter value when a part of said first combustion cycle has lapsed.

Method according to any of the previous claims, also comprising :

- determining said first parameter value when combustion of fuel has started during said first combustion cycle.

Method according to any of the previous claims, also comprising :

- determining a parameter value corresponding to said first parameter value at a number of points in time/crank angle positions during said first combustion cycle, and, for the respective determined parameter value, estimating a respective resulting temperature and/or temperature change during said first combustion cycle, and

- controlling combustion during a subsequent part of said first combustion cycle, following determination of the respective parameter value based on a respective estimated temperature and/or temperature change during said first combustion cycle.

Method according to any of claims 1-5, wherein the combustion during said subsequent part of said first combustion cycle is controlled with respect to a

resulting temperature (T_targetEvo) for said first combustion cycle .

Method according to any of claims 1-6, wherein the combustion during said subsequent part of said first combustion cycle is controlled with respect to a

temperature change during said subsequent part of said first combustion cycle.

. Method according to any of the previous claims, also comprising estimating an expected value for said physical quantity, wherein the combustion during said subsequent part of said first combustion cycle is controlled based on a comparison between said estimated value and said determined value for said physical quantity.

. Method according to any of the previous claims, wherein said temperature for said combustion constitutes a representation of an average temperature for said

combustion chamber (201) .

0. Method according to any of the previous claims, also comprising, based on said first parameter value,

estimating a representation of a resulting temperature and/or temperature change for said subsequent part of said first combustion cycle, so that said subsequent combustion is controlled based on said representation of said resulting temperature and/or temperature change for said subsequent part of said first combustion cycle.

1. Method according to claim 10, wherein said representation of a temperature and/or temperature change is estimated through an estimation of a pressure change in said combustion chamber (201) during said subsequent part of said first combustion cycle.

2. Method according to claim 11, wherein said pressure change in said combustion chamber (201) is estimated with an estimation of a heat release during said combustion.

3. Method according to claim 12, further comprising

estimating said heat release based on the amount of fuel for supply to said combustion.

14. Method according to any of the previous claims, wherein said representation of a temperature and/or temperature change during said control is represented by a

corresponding pressure and/or pressure change in said combustion chamber (201) .

15. Method according to any of the previous claims, wherein, during control of said combustion toward a temperature and/or temperature change, said control is carried out toward a pressure corresponding to said temperature in said combustion chamber (201) .

16. Method according to any of the previous claims, wherein said sensor element consists of at least a pressure sensor element (206) and wherein said first parameter value represents a pressure prevailing during said first combustion cycle in said combustion chamber (201) .

17. Method according to any of the previous claims, also

comprising controlling combustion during said subsequent part of said first combustion cycle through control of the amount of fuel for supply to said combustion chamber (201) .

18. Method according to claim 17, wherein said fuel supply to said combustion chamber is controlled through control of fuel injection with at least one fuel injector (202) .

19. Method according to claim 17 or 18, wherein at least one fuel injection is carried out during said subsequent part of said combustion cycle, wherein during said control of the fuel amount for injection and/or injection duration and/or injection pressure and/or period of time between injections is controlled for said at least one fuel injection.

20. Method according to any of claims 17-19, wherein at least two fuel injections are carried out during said

subsequent part of said combustion cycle, wherein said combustion is controlled also after said first of said at least two injections of fuel.

21. Method according to any of claims 17-20, wherein, during control of said combustion, at least three fuel

injections are carried out during said subsequent part of said combustion process, wherein, during the control of a first of said at least three fuel injections, the

remaining fuel injections are treated as one single aggregate injection.

22. Method according to any of claims 17-21, wherein control of combustion during said subsequent part of said first combustion cycle is carried out at least partly through control of fuel injected to said combustion chamber (201) during an ongoing fuel injection.

23. Method according to any of claims 17-22, further

comprising to change a distribution of fuel amounts between at least two fuel injections during the control of fuel injected to said combustion chamber (201) .

24. Method according to any of claims 17-23, further

comprising applying a predetermined injection of fuel at the start of the combustion cycle, wherein control is carried out after a first injection has at least been started, but before the fuel injection during said first combustion cycle has been completed.

25. Method according to any of the previous claims, further comprising carrying out a first fuel injection to said combustion chamber (201) during said first part of said first combustion cycle, and at least one second fuel injection during said subsequent part of said combustion cycle, where the control of said second fuel injection is determined after said first fuel injection has at least partly been completed.

6. Method according to one of the previous claims, further comprising, during said control of said combustion during said subsequent part of said combustion, determining a representation of an expected temperature and/or

temperature change for said subsequent part of said combustion cycle for at least one first and one second control alternative, respectively, and

- among several control alternatives, selecting one control alternative for control of said subsequent part of said combustion cycle.

7. Method according to claim 26, wherein said control

alternative consists of alternatives for the injection of fuel during said subsequent part of said combustion cycle .

8. Method according to any of the previous claims, also comprising to control combustion during said subsequent part of said first combustion cycle through control of one or several valves operating at said combustion chamber (201) .

9. Method according to any of the previous claims, wherein said control of said temperature is carried out with respect to a fraction and/or concentration for one or several exhaust components from the group comprising: HC, CO, NO_x, NO, N0₂, PM.

30. Method according to any of the previous claims, wherein, during said control, the combustion during said

subsequent part of said first combustion cycle is controlled with respect to a desired temperature or a desired temperature change, wherein control toward said desired temperature and/or temperature change is carried out during several combustion cycles.

31. Method according to any of the previous claims, wherein the exhaust stream resulting from combustion in said combustion engine is after treated in an after-treatment system comprising one or several from the group:

- a catalyst for the reduction of hydrocarbons and/or oxides of carbon and/or nitrogen oxides; or

- a particle reduction system. 32. Method according to any of the previous claims, wherein said first parameter value representing a physical quantity for combustion in said combustion chamber (201) is determined at least at each crank angle, every tenth of every crank angle or every hundredth of every crank angle.

33. Method according to any of the previous claims, wherein said first parameter value is determined by using one or several from the group: a cylinder pressure transmitter, a knock sensor, a strain gauge, a speed sensor, an ion current sensor.

34. Computer program comprising a program code which, when said program code is executed in a computer, achieves that said computer carries out the method according to any of the claims 1-33.

35. Computer program product comprising a computer-readable medium and a computer program according to claim 34, wherein said computer program is comprised in said computer-readable medium. 36. System for the control of a combustion engine (101), wherein said combustion engine (101) comprises at least one combustion chamber (201) and elements (202) for the supply of fuel to said combustion chamber (201) , wherein combustion in said combustion chamber (201) occurs in combustion cycles, wherein the method is characterised in that the system comprises:

- elements (115) which, during a first part of a first combustion cycle, with the help of a first sensor element (206) , determine a first parameter value representing a physical quantity for combustion in said combustion chamber (201) , and

- elements (115) , which, based on said first parameter value, control the combustion during a subsequent part of said first combustion cycle, so that during said control the combustion during said subsequent part of said first combustion cycle is controlled with respect to a

resulting temperature at said subsequent combustion.

37. System according to claim 36, characterised in that said combustion engine consists of one out of the group: a vehicle engine, a marine engine, an industrial engine.

38. Vehicle (100), characterised in that it comprises a

system according to claim 36 or 37.