Method for providing adapted throttle area and control arrangement

Abstract

The disclosure concerns a method and a control arrangement (14) of an ICE (4) comprising a throttle (6) for controlling air admitted to a combustion process. The control arrangement (14) is configured to: - measure a maximum value of a throttle position parameter at a fully open throttle position, - provide a throttle area model, comprising a correlation between representations of throttle positions and predetermined throttle areas wherein the representations are based on a minimum value of the throttle position parameter and the maximum value, - establish values of a throttle area adaptation parameter, - establish a value of the throttle area adaptation parameter at a closed throttle position, - calculate the minimum value utilising this latter value, and - determine the adapted throttle area utilising a measured value of the throttle position parameter, the throttle area model, and the throttle area adaptation parameter.

Description

[0001] METHOD FOR PROVIDING ADAPTED THROTTLE AREA AND CONTROL ARRANGEMENT

[0002] TECHNICAL FIELD

[0003] The invention relates to a method for providing an adapted throttle area of an internal

[0004] 5 combustion engine, to an internal combustion engine, and to a control arrangement of an internal combustion engine. The invention also relates to a vehicle. The invention further relates to a computer program and to a computer-readable storage medium.

[0005] BACKGROUND

[0006] 10 Air is supplied to an internal combustion engine, ICE, for combusting a fuel in cylinders of the ICE. The combustion drives a crankshaft of the ICE, which in turn powers a device such as a vehicle, a marine vessel, or an electric generator to only name a few out of innumerable applications of an ICE.

[0007] 15 The airflow to the cylinders is regulated by a throttle of the ICE. When the throttle is fully closed the airflow via the throttle is zero or close to zero. When the throttle is fully open a maximum airflow is supplied to the cylinders.

[0008] A modern ICE requires precise regulation of the supplied airflow by the throttle. Therefore, a precise positioning of the throttle is necessary. A throttle position sensor supplies throttle position data to a control arrangement of the ICE. These throttle position data are translated into throttle area and / or airflow rates through the throttle.

[0009] However, a throttle is affected e.g., by ambient temperature and other operational conditions.

[0010] 25 Accordingly, the throttle position data from the throttle position sensor have to be tailored to current operating conditions of the throttle to provide reliable throttle position data.

[0011] EP 2003316 discloses a system for weighted throttle adaptation. The system controls an air / fuel relationship of an internal combustion engine having a throttle and an intake manifold.

[0012] 30 It comprises means for calculating a true throttle area based on sampled measurements of operational data and models of variables, where each data sample is weighted by a weight factor determining its importance. Means are provided for estimating parameters of a correction equation through comparing the true throttle area to a modelled throttle area and minimizing the estimation error through optimization.

[0013] 35

[0014] US 6957140 discloses a throttle control system for a vehicle and includes a driver input that generates a control signal and a control module that generates a throttle control signal based on the control signal. The control module determines whether the throttle control signal is within one of a first and a second region, determines a compensation factor from a first lookup table when the throttle control signal is within the first region and determines the compensation factor from a second look-up table when the throttle control signal is within the second region. The control module calculates a compensated throttle control signal based on the compensation factor.

[0015] US 7024305 discloses a throttle area compensation system for use with an electronic throttle control of a vehicle and includes a compensation datastore of compensation values indexed by pre-compensated throttle area. A compensation vector learning module receives a precompensated throttle area and at least one sensed vehicle condition and informs the compensation datastore based on the pre-compensated throttle area and the sensed vehicle condition. A throttle area compensation module communicates with the compensation datastore, receives the pre-compensated throttle area, and determines a compensated throttle area based on the pre-compensated throttle area and a corresponding compensation value of the compensation data store.

[0016] SUMMARY

[0017] It would be advantageous to achieve a responsive throttle adaptation for an internal combustion engine. In particular, it would be desirable to enable a provision of an adapted throttle area that efficiently takes account of changing throttle operating conditions. To better address one or more of these concerns, one or more of a method for providing an adapted throttle area of an internal combustion engine, a control arrangement of an internal combustion engine, a vehicle, a computer program, and a computer-readable storage medium having the features defined in one or more of the independent claims is provided.

[0018] According to an aspect, there is provided a method for providing an adapted throttle area of an internal combustion engine, wherein the internal combustion engine comprises a throttle for controlling an amount of air admitted to a combustion process within the internal combustion engine. The method comprises steps of:

[0019] - measuring a maximum value of a throttle position parameter at a fully open throttle position,

[0020] - providing a throttle area model, wherein the throttle area model comprises a correlation between representations of throttle positions and predetermined throttle areas, and wherein the representations of throttle positions are based on a minimum value of the throttle position parameter and the maximum value of the throttle position parameter,

[0021] - establishing values of a throttle area adaptation parameter during operation of the internal combustion engine, - establishing a value of the throttle area adaptation parameter at a closed throttle position,

[0022] - calculating the minimum value of the throttle position parameter utilising the value of the throttle area adaptation parameter at the closed throttle position, and

[0023] - determining the adapted throttle area utilising a measured value of the throttle position parameter, the throttle area model, and the throttle area adaptation parameter.

[0024] In this manner, an adapted throttle area is provided utilising the value of the throttle area adaptation parameter at the closed throttle position, which has been used to calculate the minimum value of the throttle position parameter. Accordingly, the minimum value of the throttle position parameter to be used in the throttle area model is a calculated value linked to the throttle area adaptation parameter - as opposed to a measured value of the throttle position parameter of the physical throttle.

[0025] Since this calculated value is based on the throttle area adaptation parameter, an up-to-date throttle related parameter is utilised in the calculation of the minimum value of the throttle position parameter.

[0026] This provides a reduced mismatch between the representations of throttle positions of the throttle area model and the throttle area adaptation parameter when physical throttle operating conditions change. Also, a quicker correction of the throttle area adaptation parameter is enabled when the physical throttle operating conditions change in comparison with if the minimum value of the throttle position parameter were to be based on a measured value of the throttle position parameter at the physical closed throttle position. Moreover, when the physical throttle operating conditions remain constant, the calculated minimum value of the throttle position parameter remains relevant, i.e. a measured value of the minimum value of the throttle position parameter does not have to be established solely for the purpose of use in the throttle area model.

[0027] More specifically, the throttle area adaptation parameter is kept up to date by measuring one or more current airflow parameters of the airflow through the throttle at different representations of throttle positions. As such, the throttle area adaptation parameter may be a value, an equation, a look-up table, or similar or combinations thereof, which parameter is utilised for adaptation of the throttle area model to current throttle operating conditions of the throttle.

[0028] Accordingly, the adapted throttle area, as provided by the method and as determined in the step of determining the adapted throttle area, utilises the up-to-date throttle related parameter in the form of the throttle area adaptation parameter applied to the throttle area model.

[0029] The representations of throttle positions that are correlated with the predetermined throttle areas in the throttle area model are linked to the up-to-date throttle related parameter in the form of the throttle area adaptation parameter since the latter is utilised for providing the minimum value of the throttle position parameter.

[0030] According to a further aspect, there is provided a control arrangement of an internal combustion engine, the internal combustion engine comprising a throttle for controlling an amount of air admitted to a combustion process within the internal combustion engine. The control arrangement is configured to:

[0031] - measure a maximum value of a throttle position parameter at a fully open throttle position,

[0032] - provide a throttle area model, wherein the throttle area model comprises a correlation between representations of throttle positions and predetermined throttle areas, and wherein the representations of throttle positions are based on a minimum value of the throttle position parameter and the maximum value of the throttle position parameter,

[0033] - establish values of a throttle area adaptation parameter during operation of the internal combustion engine,

[0034] - establish a value of the throttle area adaptation parameter at a closed throttle position,

[0035] - calculate the minimum value of the throttle position parameter utilising the value of the throttle area adaptation parameter at the closed throttle position, and

[0036] - determine the adapted throttle area utilising a measured value of the throttle position parameter, the throttle area model, and the throttle area adaptation parameter.

[0037] Consequently, as discussed above with respect to the method for providing an adapted throttle area, the adapted throttle area is determined utilising the value of the throttle area adaptation parameter at the closed throttle position. Again, the minimum value of the throttle position parameter to be used in the throttle area model is a calculated value - as opposed to a measured value.

[0038] Accordingly, as discussed above, when physical throttle operating conditions change, this provides for a reduced mismatch between the representations of throttle positions of the throttle area model and the throttle area adaptation parameter and also, enabling of a quicker correction of the throttle area adaptation parameter. The internal combustion engine may herein also be referred to as the ICE or simply the engine. The ICE may be a two-stroke or four-stroke engine. The ICE may be a compression ignition ICE, such as a diesel engine.

[0039] The internal combustion engine may form part of a drivetrain of a vehicle, such as a land- based vehicle. The internal combustion engine may alternatively be utilised in or aboard a seaborn vessel or in a stationary installation such as a power source of an electric generator e.g., a so-called gen set.

[0040] The throttle of the ICE may be arranged in a charge air conduit downstream of an air intake and upstream of an intake manifold. The intake manifold distributes charge air to cylinders of the ICE. During operation of the ICE, fuel is combusted in the cylinders with the charge air. Exhaust gas is led from the cylinders via an exhaust manifold to an exhaust system of the ICE.

[0041] Between the air intake and the throttle, a charge air compressor, such as a turbo charger, and a charge air cooler may be arranged.

[0042] The control arrangement may form a part of an engine control unit, ECU, of the internal combustion engine.

[0043] The control arrangement controls at least part of operation of the ICE. For certain control of the ICE e.g., in order to fulfil a torque request from a driver or a cruise control, or for injecting appropriate amounts of fuel into the cylinders, the herein discussed adapted throttle area is utilised for estimating a current airflow through the throttle.

[0044] The adapted throttle area is an estimation of the current throttle area of the throttle.

[0045] The term current throttle area refers to a momentarily present throttle area. Accordingly, the current throttle area changes during transient and / or dynamic ICE operation. On the other hand, the current throttle area may remain constant when steady ICE operating conditions prevail.

[0046] The herein discussed providing and determining of the adapted throttle area relates to an estimate of the current throttle area. Namely, firstly, the current throttle area cannot be measured directly. Only indirect measurements of airflow parameters, such as temperature, pressure, mass airflow, etc. provided data, on the basis of which the current throttle area can be calculated. Secondly, although such calculations may provide accurate current throttle area values, the obstacle is that these calculations can only be made during steady ICE operating conditions. During transient and / or dynamic ICE operation, the measured airflow parameters change too much to base calculation of relevant throttle area values thereon.

[0047] Therefore, the throttle area model and the throttle area adaptation parameter are provided for giving a reliable estimate of a current throttle area in the form of the herein discussed adapted throttle area during transient and / or dynamic ICE operation as well as during steady operating conditions of the ICE.

[0048] As mentioned above, the throttle area model comprises a correlation between representations of throttle positions and predetermined throttle areas. For instance, representational values of the representations of throttle positions e.g., may be provided as portions of an open throttle, such as a percentage of the fully open throttle position. The predetermined throttle areas may be provided as actual throttle area values e.g., using the unit cm2.

[0049] The correlation between the representations of throttle positions and the predetermined throttle areas may be provided in the form of an equation, a look-up table, or similar or combinations thereof.

[0050] A throttle position sensor senses values of the throttle position parameter. Accordingly, the throttle position parameter may be given by the output provided by the sensor, such as by a voltage from the sensor. The control arrangement is configured for calculating the representations of throttle positions from the sensed values of the throttle position parameter.

[0051] Thus, during operation of the ICE, the control arrangement is configured to utilise the values of the throttle position parameter sensed by the throttle position sensor to provide a corresponding representation of the throttle position. The representation of the throttle position gives a corresponding throttle area value via the throttle area model.

[0052] Physical throttle parameters may be different between different throttles of the same kind e.g., due to manufacturing tolerances. But more importantly, physical throttle parameters change over time e.g., due to temperature changes, wear of mechanical parts, build-up of deposits, etc. Therefore, in order to provide precisely estimated throttle area data to the control arrangement and / or the ECU, the throttle area model requires adaptation to current operating conditions of the throttle. For such adaptation of the throttle area model to current operating conditions, the throttle area adaptation parameter is provided. As mentioned above, the throttle area adaptation parameter is kept up to date. This is enabled by the establishing of values of the throttler area adaptation parameter during operation of the ICE, and may be performed whenever the ICE is running. Hence, the throttle area adaptation parameter applied to the throttle area model will provide the adapted throttle area i.e. more precise values of the current throttle area than by the throttle area model alone.

[0053] For instance, an input for the throttle area adaptation parameter may be the representations of throttle positions and an output of the throttle area adaptation parameter may be one or more values of the throttle area adaptation parameter.

[0054] According to a further aspect there is provided an internal combustion engine comprising a throttle for controlling an amount of air admitted to a combustion process within the internal combustion engine and a control arrangement according to any one of aspects and / or embodiments discussed herein.

[0055] According to a further aspect there is provided a vehicle comprising an internal combustion engine according to any one of aspects and / or embodiments discussed herein.

[0056] According to a further aspect there is provided a computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method according to any one of aspects and / or embodiments discussed herein.

[0057] According to a further aspect there is provided a computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to carry out the method according to any one of aspects and / or embodiments discussed herein.

[0058] Further features of, and advantages with, the invention will become apparent when studying the appended claims and the following detailed description.

[0059] BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Various aspects and / or embodiments of the invention, including its particular features and advantages, will be readily understood from the example embodiments discussed in the following detailed description and the accompanying drawings, in which: Fig. 1 illustrates a vehicle according to embodiments,

[0061] Fig. 2 schematically illustrates an internal combustion engine according to embodiments, Fig. 3 schematically illustrates a control arrangement according to embodiments, Figs. 3a - 3c show examples of look-up tables,

[0062] Fig. 4 illustrates a method according to embodiments, and

[0063] Fig. 5 illustrates embodiments of a computer-readable storage medium.

[0064] DETAILED DESCRIPTION

[0065] Aspects and / or embodiments of the invention will now be described more fully. Like numbers refer to like elements throughout. Well-known functions or constructions will not necessarily be described in detail for brevity and / or clarity.

[0066] Fig. 1 illustrates a vehicle 2 according to embodiments.

[0067] The vehicle 2 may be any kind of vehicle configured for land-based propulsion, such as e.g., a bus, a truck, a heavy truck, a car, or a train. In Fig. 1, the vehicle 2 is illustrated as a heavy load vehicle in the form of a truck.

[0068] The vehicle 2 comprises an internal combustion engine 4 according to any one of aspects and / or embodiments discussed herein, such as the internal combustion engine 4 discussed below with reference to Fig. 2.

[0069] Fig. 2 schematically illustrates an internal combustion engine, ICE, 4 according to embodiments.

[0070] The ICE 4 comprises a throttle 6 for controlling an amount of air admitted to a combustion process within the ICE 4.

[0071] The throttle 6 is arranged in a charge air conduit 8 leading to an intake manifold 10 of the ICE 4. A turbo charger 12 is arranged in the charge air conduit 8 upstream of the throttle 6. Further components such as an air filter and a charge air cooler (none of them shown) may be arranged in the charge air conduit 8.

[0072] The ICE 4 further comprises a control arrangement 14 according to any one of aspects and / or embodiments discussed herein, such as the control arrangement 14 discussed below with reference to Fig 3. The ICE 4 may be comprised in a land-based vehicle as discussed above with reference to Fig. 1.

[0073] Alternatively, the ICE 4 may be comprised in a different kind of vehicle, or it may be comprised in a stationary arrangement, such as a power source of an electric current generator i.e. , part of a genset, or it may be comprised in a marine vessel.

[0074] Fig. 3 schematically illustrates a control arrangement 14 according to embodiments. Figs. 3a - 3c show examples of look-up tables. Fig. 3a illustrates an example of a throttle area model, Fig. 3b illustrates an example of correlation between values of a throttle position parameter and representations of throttle positions, and Fig. 3c illustrates an example of a throttle area adaptation parameter.

[0075] The control arrangement 14 may form part of an Engine Control Unit, ECU, of an ICE or alternatively, the control arrangement 14 may form a control arrangement configured for for controlling aspects of charge air supply to the ICE.

[0076] The ICE associated with the control arrangement 14 may be an ICE 4 as discussed above with reference to Figs. 1 and 2. The control arrangement 14 is also indicated in Fig. 2.

[0077] The control arrangement 14 is configured to be utilised in connection with the different aspects and / or embodiments of the invention. In particular, the control arrangement 14 is configured to determine an adapted throttle area. Further, the control arrangement 14 is configured to perform steps of a method 100 for providing an adapted throttle area of an internal combustion engine, see e.g. below with reference to Fig. 4.

[0078] A computer could be comprised in the control arrangement 14. A computer may be any hardware or hardware / firmware device implemented using processing circuity such as, but not limited to, a processor, Central Processing Unit (CPU), a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a System-on-Chip (SoC), a programmable logic unit, a microprocessor, an application-specific integrated circuit, or any other device capable of electronically performing operations in a defined manner.

[0079] The control arrangement 14 comprises at least one calculation unit 42, which may take the form of substantially any suitable type of processor circuit or microcomputer, e.g. a circuit for digital signal processing (digital signal processor, DSP), a Central Processing Unit (CPU), a processing unit, a processing circuit, a processor, an Application Specific Integrated Circuit (ASIC), a microprocessor, or other processing logic that may interpret and execute instructions. The herein utilised expression “calculation unit” may represent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some or all of the ones mentioned above.

[0080] The control arrangement 14 comprises a memory unit 44. The calculation unit 42 is connected to the memory unit 44, which provides the calculation unit 42 with, e.g. one or more of stored programme code, data tables, and / or other stored data which the calculation unit 42 needs to enable it to do calculations and to provide and / or determine the adapted throttle area. The calculation unit 42 is also adapted to store partial or final results of calculations in the memory unit 44.

[0081] The memory unit 44 may comprise a physical device utilised to store data or programs, i.e. sequences of instructions on a temporary and / or permanent basis. According to some embodiments, the memory unit 44 may comprise integrated circuits comprising silicon-based transistors. The memory unit 44 may comprise e.g. a memory card, a flash memory, a USB memory, a hard disc, or another similar volatile or non-volatile storage unit for storing data such as e.g. ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), EEPROM (Electrically Erasable PROM), etc. in different embodiments.

[0082] In the embodiment depicted, only one calculation unit 42 and memory 44 are shown, but the control arrangement 14 may alternatively comprise more than one calculation unit and / or memory unit.

[0083] The control arrangement 14 is further provided with respective devices 40, 46, 48 for receiving and / or sending input and output signals. These input and output signals may comprise waveforms, pulses or other attributes, which can be detect as information by signal receiving devices, and which can be converted to signals processable by the calculation unit 42. Input signals are supplied to the calculation unit 42 from the input receiving devices 46, 48. Output signal sending devices 40 are arranged to convert calculation results from the calculation unit 42 to output signals for conveying to signal receiving devices of the control arrangement 14. Each of the connections to the respective devices for receiving and sending input and output signals may take the form of one or more from among a cable, a data bus, e.g. a CAN (controller area network) bus, a MOST (media orientated systems transport) bus or some other bus configuration, or a wireless connection. Mentioned as examples, the output signal sending devices 40 may send control signals to the throttle 6 for controlling a throttle position and accordingly, an airflow to the manifold of the ICE. The input signal receiving devices 46, 48 may receive signals from a throttle position sensor 16 of the throttle 6 and other sensors 18 related to charge air parameters, such as one or more of a temperature sensor, a pressure sensor, a mass flow sensor arranged at one or more positions of the charge air conduit.

[0084] Examples of a data tables may be look-up tables provided for a throttle area model and / or for a throttle area adaptation parameter. Examples of data may be measured, monitored, and / or calculated data. As mentioned, the control arrangement 14 is connected to various sensors and actuators in order to receive input and provide output for performing the various aspects and embodiments of the method discussed herein. Some of the various sensors are exemplified above. An example of an actuator may be a throttle actuator configured for changing a position of the throttle 6 i.e., to set a throttle area of the throttle 6.

[0085] The control arrangement 14 is a control arrangement of an internal combustion engine, such as the ICE 4 discussed with reference to Figs. 1 and 2. Accordingly, the internal combustion engine comprising a throttle 6 for controlling an amount of air admitted to a combustion process within the internal combustion engine.

[0086] The control arrangement 14 is configured to measure a maximum value of a throttle position parameter at a fully open throttle position. For instance, as part of a starting procedure of the ICE, the throttle 6 is moved to its fully open position by the throttle actuator and a measurement of the maximum value of the throttle position parameter by the throttle position sensor 16 is made, such as a measurement of a maximum voltage.

[0087] The control arrangement 14 is further configured to provide a throttle area model, wherein the throttle area model comprises a correlation between representations of throttle positions and predetermined throttle areas, and wherein the representations of throttle positions are based on a minimum value of the throttle position parameter and the maximum value of the throttle position parameter.

[0088] The minimum value of the throttle position parameter and the maximum value of the throttle position parameter represent values of the respective end positions of the throttle 6. The maximum value is measured as discussed above. The minimum value, as explained below, is a calculated value. For instance, the throttle area model may be provided in the form of a look-up table, as illustrated in the example of Fig. 3a, in which the representations of throttle positions are correlated with the predetermined throttle areas. Alternatively, e.g., the throttle area model may be provided in the form of a formula or an equation that correlates the representations of throttle positions with the predetermined throttle areas.

[0089] The representations of throttle positions may be provided as a percentage of the fully open throttle position. The predetermined throttle areas may be provided as throttle area values. Thus, for instance, the throttle area model may provide a correlation between percentages of the fully open throttle position and respective throttle area values.

[0090] During operation of the ICE, the throttle position sensor 16 provides measurements of values of the throttle position parameter. The control arrangement 14 determines the representations of throttle positions based on the measurements of the values of the throttle position parameter provided by the throttle position sensor 16, such as percentages of the fully open throttle position as in the example above.

[0091] Fig. 3b illustrates a look-up table correlating values of the throttle position parameter with representations of throttle positions.

[0092] The control arrangement 14 is further configured to establish values of a throttle area adaptation parameter during operation of the internal combustion engine.

[0093] By establishing values of the throttle area adaptation parameter during operation of the ICE, the throttle area adaptation parameter provides an up-to-date parameter related to present physical operating conditions of the throttle 6. See further below concerning example embodiments of the establishing of the throttle area adaptation parameter.

[0094] When one or more values of the throttle area adaptation parameter are applied to the throttle area model, a correction of the throttle area values of the throttle area model is achieved such that more precise throttle area values are provided than by the throttle area model alone are provided, i.e. adapted throttle area values are provided, see further below.

[0095] The throttle area adaptation parameter may be provided in the form of a look-up table, as illustrated in Fig. 3c, or as an equation. For instance, the throttle area adaptation parameter may correlate representations of throttle positions with one or more values of the throttle area adaptation parameter.

[0096] The throttle area adaptation parameter may be provided over the entire operating range of the throttle 6, closed to fully open throttle. Alternatively, the throttle area adaptation parameter may be provided only for a partial operating range of the throttle 6 e.g., for a lower operating range of the throttle 6, such as a lower third of its operating range. In such case, in an upper operating range of the throttle 6, the throttle area values of the throttle area model may be utilised by the control arrangement 14 for providing a throttle area to be utilised in the determining of an airflow through the throttle 6.

[0097] The control arrangement 14 is further configured to establish a value of the throttle area adaptation parameter at a closed throttle position, corresponding to value “Y” in the table of Fig. 3c.

[0098] The value of the throttle area adaptation parameter at the closed throttle position may be read directly from a look-up table representing the throttle area adaptation parameter or it may be calculated. In the latter case, extrapolation of values of the throttle area adaptation parameter may provide the value of the throttle area adaptation parameter at the closed throttle position or a different calculation model may be applied to values of the throttle area adaptation parameter for establishing the value of the throttle area adaptation parameter at the closed throttle position.

[0099] The control arrangement 14 is further configured to calculate the minimum value of the throttle position parameter utilising the value of the throttle area adaptation parameter at the closed throttle position.

[0100] Thus, the minimum value of the throttle position parameter, to be utilised in the throttle area model for the representations of throttle positions is a calculated value. Moreover, since the minimum value of the throttle position parameter is calculated utilising the value of the throttle area adaptation parameter at the closed throttle position, the up-to-date throttle area adaptation parameter ensures that the minimum value of the throttle position parameter relates to current operating conditions of the throttle 6. The minimum value of the throttle position parameter is indicated by the value “Vmin” in the table of Fig. 3b, which is calculated utilising the value represented by “Y” in the table of Fig. 3c. Accordingly, when applied to the throttle area model, this calculated minimum value of the throttle position parameter, eliminates, or at least reduces a mismatch between the representations of throttle positions of the throttle area model and the representations of throttle positions of the throttle area adaptation parameter when physical throttle operating conditions change.

[0101] Put differently, the calculated minimum value of the throttle position parameter utilising the value of the throttle area adaptation parameter at the closed throttle position decouples the closed throttle position utilised in the throttle area model from a physical closed throttle position. This means that the closed throttle position of the throttle area model is steadily based on the up-to-date throttle area adaptation parameter and is not directly based in measurements of changing closed throttle positions of the physical throttle 6.

[0102] A factor or a formula may be applied when calculating the minimum value of the throttle position parameter utilising the value of the throttle area adaptation parameter at the closed throttle position. The factor or formula provides a conversion from the unit of the throttle area adaptation parameter to the unit of the throttle position parameter.

[0103] The control arrangement 14 is configured to determine the adapted throttle area utilising a measured value of the throttle position parameter, the throttle area model, and the throttle area adaptation parameter.

[0104] Thus, measured values of the throttle position parameter, measured by the throttle position sensor 16, are utilised to provide the adapted throttle area i.e., estimated values of the throttle area for different throttle positions.

[0105] Since, as mentioned above, the mismatch of the throttle area model is at least reduced when physical operation conditions of the throttle 6 change - by utilising the calculated minimum value of the throttle position parameter, the determined and thus, provided, adapted throttle area - leads to reliable estimated values of the throttle area and quicker correction of the throttle area adaptation parameter.

[0106] According to embodiments, the control arrangement 14, in connection with providing the throttle area model, may be further configured to:

[0107] - limit a value range of the representations of throttle positions by a minimum representational value corresponding to the minimum value of the throttle position parameter and a maximum representational value corresponding to the maximum value of the throttle position parameter. In this manner, a range of the representations of throttle positions may be provided and the range is linked to the calculated minimum value of the throttle position parameter and the measured maximum value of the throttle position parameter.

[0108] Sensor values provided by the throttle position sensor 16 to the calculation unit 42 thus, may be correlated with representational values of the representations of throttle positions within the range between the minimum representational value and the maximum representational value, as shown by the table of Fig. 3b.

[0109] The throttle area model may correlate such representational values of the representations of throttle positions within the entire range between the minimum representational value and the maximum representational value with relevant respective throttle area values, as shown by the table of Fig. 3a.

[0110] Also the throttle area adaptation parameter may correlate such representational values of the representations of throttle positions within the entire range, or a portion of the range, between the minimum representational value and the maximum representational value with one or more throttle area adaptation parameter values, as shown by the table of Fig. 3c.

[0111] According to embodiments, the control arrangement 14, in connection with establishing values of the throttle area adaptation parameter during operation of the internal combustion engine, is further configured to:

[0112] - measure at least one physical parameter related to an airflow into the internal combustion engine at a representation of a current throttle position,

[0113] - calculate a current actual throttle area based on the at least one physical parameter of the airflow into the internal combustion engine at the representation of the current throttle position, and

[0114] - calculate a value of the throttle area adaptation parameter based on a difference between the current actual throttle area and a predetermined area of the throttle area model at the representation of the current throttle position. In this manner, the throttle area adaptation parameter may be kept up to date with changing physical throttle operating parameters in order to provide one or more relevant values of the throttle area adaptation parameter to be applied in the determining of the adapted throttle area.

[0115] Accordingly, the throttle area adaptation parameter may be intermittently updated while the ICE is running. The above discussed sensor / s 18 related to charge air parameters, such as temperature, pressure, and / or mass flow may be utilised for measuring the at least one physical parameter related to the airflow into the ICE. A current value of the throttle position parameter measured by the throttle position sensor 16 is converted into a representation of the current throttle position e.g., utilising the look-up table of Fig. 3b.

[0116] One or more of the charge air parameters provide basis for the calculation unit 42 to calculate the current actual throttle area at the representation of the current throttle position.

[0117] The value of the throttle area adaptation parameter, which has been calculated based on the difference between the current actual throttle area and the predetermined area of the throttle area model at the representation of the current throttle position, is an up-to date value that is available for updating the throttle area adaptation parameter.

[0118] The values of the throttle area adaption parameter may take the form of correction factors or offsets applicable to the throttle area model. The throttle area adaptation parameter may be provided in the form of a look-up table of similar size as a look-up table of the throttle area model.

[0119] The throttle area adaptation parameter with its values may be updated and stored in the memory unit 44.

[0120] In order to measure the at least one physical parameter related to an airflow into the internal combustion engine, and to calculate the current actual throttle area based on the at least one physical parameter of the airflow into the internal combustion engine, at the representation of the current throttle position, stable ICE operating conditions have to prevail. Accordingly, values of the throttle area adaptation parameter can only be updated when the ICE is operating under stable conditions. Stable operating conditions prevail e.g., when the ICE produces constant power over a minimum duration that allows the measured at least one physical parameter to stabilise.

[0121] Stable operating conditions occur at different throttle positions and not necessarily at precisely the representations of throttle positions provided by the throttle area adaptation parameter. This means that firstly, the throttle positions for which values of the throttle area adaptation parameter are calculated may differ and that secondly, values of the throttle area adaptation parameter for some of the representations of throttle positions may have to be calculated e.g., by interpolation. According to embodiments, the throttle position parameter may be a voltage.

[0122] Such a voltage may be measured by the throttle position sensor 16 and provided to the calculation unit 42 to convert the voltage into a representation of the throttle position e.g., utilising the look-up table of Fig. 3b.

[0123] According to embodiments, the control arrangement 14 may be further configured to:

[0124] - measure a value of the throttle position parameter at the closed throttle position,

[0125] - limit a minimum physical throttle position to a position corresponding to the larger value of: a physical throttle position corresponding to the value of the throttle position parameter at the closed throttle position determined when measuring the value of the throttle position parameter at the closed throttle position, and a physical throttle position corresponding to the minimum value of the throttle position parameter determined when calculating the minimum value of the throttle position parameter. In this manner, damaging the throttle 6 may be avoided in case the calculated minimum value of the throttle position parameter should correspond to a value below the physical closed throttle position.

[0126] The throttle position sensor 16 may be utilised for measuring the value of the throttle position parameter at the closed throttle position. For instance, as part of a starting procedure of the ICE, the throttle 6 is moved to its closed position by the throttle actuator and the throttle position sensor 16 measures the corresponding value e.g., by providing a corresponding voltage.

[0127] Fig. 4 illustrates a method 100 for providing an adapted throttle area of an internal combustion engine.

[0128] The method 100 may be applied in an ICE 4 as discussed above with reference to Figs. 1 - 3. Accordingly, in the following reference is also made to Figs. 1 - 3 and the related descriptions. The control arrangement 14 discussed above may be configured for performing steps of the method 100.

[0129] For corresponding features of the method 100 and the configuration of the control arrangement 14 herein, corresponding advantages and discussions apply. The method 100 is a method 100 for providing an adapted throttle area of an internal combustion engine 4, wherein the ICE 4 comprises a throttle 6 for controlling an amount of air admitted to a combustion process within the ICE 4.

[0130] The method 100 comprises steps of:

[0131] - measuring 102 a maximum value of a throttle position parameter at a fully open throttle position,

[0132] - providing 104 a throttle area model, wherein the throttle area model comprises a correlation between representations of throttle positions and predetermined throttle areas, and wherein the representations of throttle positions are based on a minimum value of the throttle position parameter and the maximum value of the throttle position parameter,

[0133] - establishing 106 values of a throttle area adaptation parameter during operation of the internal combustion engine 4,

[0134] - establishing 108 a value of the throttle area adaptation parameter at a closed throttle position,

[0135] - calculating 110 the minimum value of the throttle position parameter utilising the value of the throttle area adaptation parameter at the closed throttle position, and

[0136] - determining 112 the adapted throttle area utilising a measured value of the throttle position parameter, the throttle area model, and the throttle area adaptation parameter.

[0137] Similarly to the discussion above with reference to the control arrangement 14:

[0138] - The step of measuring 102 the maximum value of a throttle position parameter at the fully open throttle position may be performed as part of a starting procedure of the ICE 4. The starting procedure may include moving the throttle 6 to its fully open position and measure the maximum value of the throttle position parameter.

[0139] - In the step of providing 104 the throttle area model, it may be provided in the form of a lookup table, in which the representations of throttle positions are correlated with the predetermined throttle areas. Alternatively, e.g., the throttle area model may be provided in the form of an equation that correlates the representations of throttle positions with the predetermined throttle areas. The throttle area model may provide a correlation between percentages of the fully open throttle position and respective throttle area values.

[0140] - The step of establishing 106 values of the throttle area adaptation parameter during operation of the ICE 4, provides an up-to-date parameter related to present physical operating conditions of the throttle 6. Accordingly, when the throttle area adaptation parameter is applied to the throttle area model, a correction of the throttle area values of the throttle area model is achieved such that more precise throttle area values are provided than by the throttle area model alone. - The step of establishing 108 the value of the throttle area adaptation parameter at the closed throttle position, may comprises reading the value from a look-up table representing the throttle area adaptation parameter or calculating the value.

[0141] - The step of calculating 110 the minimum value of the throttle position parameter utilising the value of the throttle area adaptation parameter at the closed throttle position provides a calculated value related to current operating conditions of the throttle 6. When applied to the throttle area model, this calculated minimum value of the throttle position parameter, eliminates, or at least reduces a mismatch between the representations of throttle positions of the throttle area model and the throttle area adaptation parameter when physical throttle operating conditions change.

[0142] - The step of determining 112 the adapted throttle area utilising the measured value of the throttle position parameter, the throttle area model, and the throttle area adaptation parameter provide the adapted throttle area i.e. , estimated values of the throttle area for different throttle positions. During use of the ICE 4, these provided adapted throttle areas can be utilised for precise control of supply of charge air to the combustion in the ICE 4.

[0143] According to embodiments, in the step of providing 104 the throttle area model, a value range of the representations of throttle positions may be limited by a minimum representational value corresponding to the minimum value of the throttle position parameter and a maximum representational value corresponding to the maximum value of the throttle position parameter. In this manner, a range of the representations of throttle positions may be provided and the range may be linked to the calculated minimum value of the throttle position parameter and the measured maximum value of the throttle position parameter. See also above with reference to the control arrangement 14.

[0144] According to embodiments, the step of establishing 106 values of the throttle area adaptation parameter during operation of the internal combustion engine 4, may comprise steps of:

[0145] - measuring 114 at least one physical parameter related to an airflow into the internal combustion engine 4 at a representation of a current throttle position,

[0146] - calculating 116 a current actual throttle area based on the at least one physical parameter of the airflow into the internal combustion engine 4 at the representation of the current throttle position, and

[0147] - calculating 118 a value of the throttle area adaptation parameter based on a difference between the current actual throttle area and a predetermined area of the throttle area model at the representation of the current throttle position. In this manner, the throttle area adaptation parameter may be kept up to date with changing physical throttle operating conditions in order to provide one or more relevant values of the throttle area adaptation parameter to be applied in the step of determining 112 the adapted throttle area. See also above with reference to the control arrangement 14.

[0148] According to embodiments, the throttle position parameter may be a voltage.

[0149] According to embodiments, the method 100 may comprise steps of:

[0150] - measuring 120 a value of the throttle position parameter at the closed throttle position,

[0151] - limiting 122 a minimum physical throttle position to a position corresponding to the larger value of: a physical throttle position corresponding to the value of the throttle position parameter at the closed throttle position determined in the step of measuring 120 the value of the throttle position parameter at the closed throttle position, and a physical throttle position corresponding to the minimum value of the throttle position parameter determined in the step of calculating 110 the minimum value of the throttle position parameter. In this manner, damaging the throttle 6 may be avoided in case the calculated minimum value of the throttle position parameter should correspond to a value below the physical closed throttle position. See also above with reference to the control arrangement 14.

[0152] Fig. 5 illustrates embodiments of a computer-readable storage medium 99 comprising instructions which, when executed by a computer or calculation unit 42, cause the computer or calculation unit 42 to carry out the steps of the method 100 according to any one of aspects and / or embodiments discussed herein.

[0153] The computer-readable storage medium 99 may be provided for instance in the form of a data carrier carrying computer program code for performing at least some of the steps 102 - 122 according to some embodiments when being loaded into the one or more calculation units 42. The data carrier may be, e.g. a ROM (read-only memory), a PROM (programable read-only memory), an EPROM (erasable PROM), a flash memory, an EEPROM (electrically erasable PROM), a hard disc, a CD ROM disc, a memory stick, an optical storage device, a magnetic storage device or any other appropriate medium such as a disk or tape that may hold machine readable data in a non-transitory manner. The computer-readable storage medium may furthermore be provided as computer program code on a server and may be downloaded to the calculation unit 42 remotely, e.g., over an Internet or an intranet connection, or via other wired or wireless communication systems. In some embodiments, the computer-readable storage medium 99 may be a non-transitory computer-readable medium, such as a tangible electronic, magnetic, optical, infrared, electromagnetic, and / or semiconductor system, apparatus, and / or device.

[0154] The computer-readable storage medium 99 shown in Fig. 5 is a nonlimiting example in the form of a USB memory stick.

[0155] According to a further aspect, there is provided a computer program comprising instructions which, when the program is executed by a computer, causes the computer to carry out a method 100 according to any one of aspects and / or embodiments discussed herein.

[0156] One skilled in the art will appreciate that the method 100 for providing an adapted throttle area of an internal combustion engine 4, may be implemented by programmed instructions. These programmed instructions are typically constituted by a computer program, which, when it is executed in a computer or calculation unit 42, ensures that the computer or calculation unit 42 carries out the desired control, such as the method steps 102 - 122 according to the invention. The computer program is usually part of a computer-readable storage medium which comprises a suitable digital storage medium on which the computer program is stored.

[0157] It is to be understood that the foregoing is illustrative of various example embodiments and that the invention is defined only by the appended claims. A person skilled in the art will realize that the example embodiments may be modified, and that different features of the example embodiments may be combined to create embodiments other than those described herein, without departing from the scope of the invention, as defined by the appended claims.

Claims

CLAIMS1. A method (100) for providing an adapted throttle area of an internal combustion engine (4), wherein the internal combustion engine (4) comprises a throttle (6) for controlling an amount of air admitted to a combustion process within the internal combustion engine (4), and wherein the method (100) comprises steps of:- measuring (102) a maximum value of a throttle position parameter at a fully open throttle position,- providing (104) a throttle area model, wherein the throttle area model comprises a correlation between representations of throttle positions and predetermined throttle areas, and wherein the representations of throttle positions are based on a minimum value of the throttle position parameter and the maximum value of the throttle position parameter,- establishing (106) values of a throttle area adaptation parameter during operation of the internal combustion engine (4),- establishing (108) a value of the throttle area adaptation parameter at a closed throttle position,- calculating (110) the minimum value of the throttle position parameter utilising the value of the throttle area adaptation parameter at the closed throttle position, and- determining (112) the adapted throttle area utilising a measured value of the throttle position parameter, the throttle area model, and the throttle area adaptation parameter.

2. The method (100) according to claim 1, wherein in the step of providing (104) the throttle area model, a value range of the representations of throttle positions is limited by a minimum representational value corresponding to the minimum value of the throttle position parameter and a maximum representational value corresponding to the maximum value of the throttle position parameter.

3. The method (100) according to claim 1 or 2, wherein the step of establishing (106) values of the throttle area adaptation parameter during operation of the internal combustion engine (4), comprises steps of:- measuring (114) at least one physical parameter related to an airflow into the internal combustion engine (4) at a representation of a current throttle position,- calculating (116) a current actual throttle area based on the at least one physical parameter of the airflow into the internal combustion engine (4) at the representation of the current throttle position, and- calculating (118) a value of the throttle area adaptation parameter based on a difference between the current actual throttle area and a predetermined area of the throttle area model at the representation of the current throttle position.

4. The method (100) according to any one of the preceding claims, wherein the throttle position parameter is a voltage.

5. The method (100) according to any one of the preceding claims, comprising steps of:- measuring (120) a value of the throttle position parameter at the closed throttle position,- limiting (122) a minimum physical throttle position to a position corresponding to the larger value of: a physical throttle position corresponding to the value of the throttle position parameter at the closed throttle position determined in the step of measuring the value of the throttle position parameter at the closed throttle position, and a physical throttle position corresponding to the minimum value of the throttle position parameter determined in the step of calculating the minimum value of the throttle position parameter.

6. A control arrangement (14) of an internal combustion engine (4), the internal combustion engine (4) comprising a throttle (6) for controlling an amount of air admitted to a combustion process within the internal combustion engine (4), wherein the control arrangement (14) is configured to:- measure a maximum value of a throttle position parameter at a fully open throttle position,- provide a throttle area model, wherein the throttle area model comprises a correlation between representations of throttle positions and predetermined throttle areas, and wherein the representations of throttle positions are based on a minimum value of the throttle position parameter and the maximum value of the throttle position parameter,- establish values of a throttle area adaptation parameter during operation of the internal combustion engine (4),- establish a value of the throttle area adaptation parameter at a closed throttle position,- calculate the minimum value of the throttle position parameter utilising the value of the throttle area adaptation parameter at the closed throttle position, and- determine the adapted throttle area utilising a measured value of the throttle position parameter, the throttle area model, and the throttle area adaptation parameter.

7. The control arrangement (14) according to claim 6, wherein the control arrangement (14) in connection with providing the throttle area model is further configured to:- limit a value range of the representations of throttle positions by a minimum representational value corresponding to the minimum value of the throttle position parameter and a maximum representational value corresponding to the maximum value of the throttle position parameter.

8. The control arrangement (14) according to claim 6 or 7, wherein the control arrangement (14) in connection with establishing values of the throttle area adaptation parameter during operation of the internal combustion engine (4), is further configured to:- measure at least one physical parameter related to an airflow into the internal combustion engine (4) at a representation of a current throttle position,- calculate a current actual throttle area based on the at least one physical parameter of the airflow into the internal combustion engine (4) at the representation of the current throttle position, and- calculate a value of the throttle area adaptation parameter based on a difference between the current actual throttle area and a predetermined area of the throttle area model at the representation of the current throttle position.

9. The control arrangement (14) to any one of claims 6 - 8, wherein the throttle position parameter is a voltage.

10. The control arrangement (14) according to any one of claims 6 - 9, being further configured to:- measure a value of the throttle position parameter at the closed throttle position,- limit a minimum physical throttle position to a position corresponding to the larger value of: a physical throttle position corresponding to the value of the throttle position parameter at the closed throttle position determined when measuring the value of the throttle position parameter at the closed throttle position, and a physical throttle position corresponding to the minimum value of the throttle position parameter determined when calculating the minimum value of the throttle position parameter.

11. An internal combustion engine (4) comprising a throttle for controlling an amount of air admitted to a combustion process within the internal combustion engine (4) and a control arrangement (14) according to any one of claim 6 - 10.

12. A vehicle (2) comprising an internal combustion engine (4) according to claim 11.

13. A computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method (100) according to any one of claims 1 - 5.

14. A computer-readable storage medium (99) comprising instructions which, when executed by a computer, cause the computer to carry out the method (100) according to any one of claims 1 - 5.

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