GB2470389A - Estimating of the mean temperature of the combustion chamber of an i.c. engine - Google Patents
Estimating of the mean temperature of the combustion chamber of an i.c. engine Download PDFInfo
- Publication number
- GB2470389A GB2470389A GB0908748A GB0908748A GB2470389A GB 2470389 A GB2470389 A GB 2470389A GB 0908748 A GB0908748 A GB 0908748A GB 0908748 A GB0908748 A GB 0908748A GB 2470389 A GB2470389 A GB 2470389A
- Authority
- GB
- United Kingdom
- Prior art keywords
- parameter
- temperature
- engine
- value
- combustion chamber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D35/00—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
- F02D35/02—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions
- F02D35/025—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions by determining temperatures inside the cylinder, e.g. combustion temperatures
- F02D35/026—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions by determining temperatures inside the cylinder, e.g. combustion temperatures using an estimation
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D35/00—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
- F02D35/02—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/30—Controlling fuel injection
- F02D41/38—Controlling fuel injection of the high pressure type
- F02D41/40—Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
- F02D41/402—Multiple injections
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Abstract
A method of estimating the mean temperature of the combustion chamber of an i.c engine, e.g a direct injection common rail diesel engine with pilot, pre-, main, after and post injections, comprises: (a) experimentally creating a parameter map in which the value of an engine operation parameter influencing the temperature of the combustion chamber is measured as a function of engine speed and engine load; (b) experimentally creating a temperature map in which the expected temperature is measured in function of engine speed and engine load; (c) experimentally changing the value of the operation parameter and measuring the actual temperature for each couple of values of engine speed and engine load of the parameter map; (d) creating a function F(changed parameter value,expected parameter value) for each couple of values of engine speed and engine load of the parameter map associating the changed parameter value with the value of a parameter stored in the parameter map; (e) creating a correction map in which for each couple of values of the engine load, or engine speed, and of the function F corresponds a correction parameter value expression of the variation of the expected temperature to the variation of the parameter, and (f) using the correction parameter values of said correction maps to determine an estimation of the combustion chamber temperature given by the temperature map in function of the engine speed and of the engine load.
Description
1.iE'TD 10 ESTD1 1.TURE OF A Q21BtYSTICW G17MRER OF N 1N1ERNAL QUS1TON
TEL FID
The present invention relates to a method for estimating the temperature of the combustion chamber of an internal combustion engine.
The invention finds a particularly advantageous application in the field of directed injection common rail multijet diesel engines.
BAKJND OF THE XNVENTI
A diesel engine system generally comprises a plurality of combustion chambers which are individually defined by a reciprocating piston inside a cylinder.
The cylinder is provided with one or more intake valves for cyclically opening the combustion chamber towards an intake line for receiving fresh airflow, and with one or more exhaust valves for cyclically opening the combustion chamber towards an exhaust line for discharging the exhaust gases.
The cylinder is also provided with electrically controllable injection means, which are controlled by a microprocessor based controller (ECU), for injecting fuel inside the combustion chamber according to a multi-injection pattern.
During normal engine operation, the multi-injection pattern usually comprises several injections of fuel which follow one another in the time period between the closure of the intake valves, and the instant when the piston reaches its top dead center position (TIX), during the compression stroke.
Such injected fuel burns inside the combustion chamber producing high temperature and pressure gases, whose expansion directly apply force to the piston for moving it towards its bottom dead center position (BDC), in a power stroke which is useful for generating torque at the crankshaft.
The heat released during the combustion of the fuel, and as a consequence the mean temperature inside the combustion chamber, is strictly related to the injection pattern, i.e. to the number, the start and the duration of injection for each injection pulse, and to fresh air supplied at the engine intake.
The estimation of the mean temperature inside the combustion chamber is important to control and to regulate the working of several components of the engine.
For instance, the estimation of the combustion chamber is important to determine the working time of the glow plug and to regulate the energy supplied to it on base of temperature of the combustion chamber.
ode1s for the estimation of the temperature of the combustion chamber are already known in the art. Said models allow determining the combustion chamber temperature in different points of the combustion chamber, however they are very complex and require a very powerful hardware to be implemented.
An object of the present invention is to make available a method for estimating the mean combustion chamber temperature which is simple and reliable and it does not required a powerful hardware to be implemented.
This object is attained by the characteristics of the invention as reported in independent claims. The dependent claims delineate preferred and/or especially advantageous aspects of the invention.
DISa.OSURE OF THE flVICT It's known that during operation of the engine the ECU regulates the multi-injection pattern on the base of current engine speed and engine load, and it commands and controls the injection means according to a plurality of mapped expected values of engine operating parameters.
The invention provides method for the estimation of the mean temperature of the combustion chamber of an internal combustion engine provided with a control system, which comprises sensor means for providing respective measures of a plurality of engine operating parameters, and a microprocessor based controller (ECU).
The method according to the invention comprises the following steps: a. experimentally creating at least a parameter map in which, in function of the engine speed and of the engine load, the value (expected parameter value) of one engine operation parameter (I) influencing the temperature of the combustion chamber is measured; b. experimentally creating a temperature map in which the combustion chamber temperature (expected temperature value) is measured in function of the engine speed and of the engine load; c. experimentally change the value of said one operation parameter (changed parameter value) and measuring the temperature (actual temperature) of the combustion chamber for each couple of values of engine speed and engine load of the parameter map; d. create a function F(changed parameter value, expected parameter value) for each couple of values of engine speed and engine load of the at least one parameter map associating the changed parameter value with the expected value of parameter stored in the parameter map; e. creating a correction map for the temperature map in which for each couple of values of the engine load, or engine speed, and of the function F(changed parameter value, expected parameter value) corresponds a correction parameter value expression of the variation of the measured temperature to the variation of the parameter; f. use the correction parameter values of said correction maps to determine an estimation of the combustion chamber temperature on the base of the combustion chamber mapped temperature given by the temperature map in function of the speed load and the speed engine.
According to the invention the function F(changed parameter value, expected parameter value) is equal to the difference between the Expected parameter and the changed parameter value when the parameter is an injection pulses timing or an injection pulses angle or the intake air temperature.
As injection pulses timing can be chosen for instance the time interval between the end of an injection pulse and the beginning of the next injection pulse (Dwell_Time) while as injection pulses angle can be chosen for instance the start of pre injection angle (PRE-SOl) or the angle of start of main injection (MAIN-SOl) While the function F(changed parameter value, expected parameter value) is equal to the division of the Expected parameter with the measured parameter when the parameter is intake air flow (IAF) or an injection pulses quantity. As an injection pulses quantity can be chosen for instance the pre injection fuel quantity (PRE) The correction map is then created by storing, for each couple of values i) of the function F (measured parameter value, mapped parameter value) and of ii) the engine speed or the engine load, a correction value Vcorrection given by the following equation: V -expected -measured COITCCtIOC T 1expected These steps are repeated for each parameter, kept into consideration, whose variation has an influence on the combustion chamber temperature.
Once a correction map for each parameter influencing the combustion chamber temperature has been created, the correction values are used to correct the expected temperature in function of each couple of values of engine speed and engine load.
According to the invention the estimated temperature of the combustion chamber is given by the following equation: Te.clinlaled xp ecud [T correcgion (i) wherein i=1,...,n is the correction value corresponding to the parameter (i) kept into consideration.
It will be easily to be understood that more parameters (i) influencing the temperature will be kept into consideration more precise will be the estimation of the temperature of the combustion chamber.
As a matter of fact, the method allows a faster and more effective estimation of the temperature inside the combustion chamber during operation of the engine, which can be easily built in the ECU without requiring hardware modification.
The estimation of temperature inside the combustion chamber may be used for several different scopes, as to identify the thermal state of the engine, or to protect the turbo-charger against over-temperature, or to deactivate the glow plugs when the combustion chamber temperature reaches a prefixed value, as told above, or also as input data for model of estimation of coolant temperature of the engine.
BRIEF DEScRIPI* OF THE DRAWINGS The present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic illustration of the method according to the invention; DE1SCRIPTICI OF THE PREFERRED 1BCDD4E2T A preferred embodiment of the present invention is applied to a multi-jet diesel engine system. In this kind of engines the fuel is injected in the combustion chamber according to a specified pattern which comprises the following different injection: a PILOT injection, at least one PRE injection, a MAIN injection, at least one AFTER injection and at least one POST injection.
As told above integral to the diesel engine system is a control system, which comprises sensor means for providing respective measures of a plurality of engine operating parameters (i), and a microprocessor based controller (ECU).
One of the most important tasks of the ECU is, during operation of the engine, to determine and regulate the multi-injection pattern on the base of current engine speed and engine load, and to command and control fuel injection means according to a plurality of mapped expected values of engine operating values.
In detail, the ECU comprises a plurality of maps for at least the most important operating parameters of the engine in which, for each couple of values of engine speed and engine load, a value of said parameters are stored. The stored values are obtained by measuring the corresponding parameters in reference conditions, i.e. during laboratory test and are called expected parameters.
The most important engine parameters used by the invention in the present example and mapped in the ECU are the intake air flow, the quantity of fuel of the PRE INJECTION (PRE quantity), the angle of the crankcase at which the PRE injection starts (PRE SQl), the angle of the crankcase at which the MAIN injection starts (MAIN SQl), and the intake air temperature.
This does not mean that other engine parameters influencing the temperature cannot be taken into consideration, such as for example the coolant temperature, in carrying out other embodiments of the invention.
As told above, the ECU usually applies the values of the different parameters to regulate the operation of the engine in function of the engine speed and engine load.
Usually the engine speed is generally expressed in terms of angular speed [ipu] of the crankshaft, while the engine load, is generally expressed in term of engine fuelling [mm3 of injected fuel per cycle] or in terms of engine torque [Nm].
According to the invention the method to estimate the mean temperature of the combustion chamber provides that a map of the combustion chamber temperature, called expected temperature (Texpected), is experimentally created by measuring the combustion chamber temperature at different values of engine speed and engine load. The measuring of the expected temperature (Texpected) is performed, during laboratory tests, by means of a thermocouple included in the usual glow plug, which is well known in the art.
Next, experimentally, a first parameter is considered, for instance the expected intake air flow (IAF) The value of expected intake air flow is changed, keeping unchanged the values of the other parameters, and a new measuring of the temperature Tmeasured of the combustion chamber is performed by means of the thermocouple, for each couple of values of engine speed and engine load.
According to the invention a function F(changed intake air flow value; expected intake air flow value) is created for each couple of values of engine speed and engine load of the expected intake air flow map associating the changed intake air flow value, by means of an usual air flow sensor, with the expected value of intake air flow stored in the intake air flow map. The function F is given by the following equation: F (Expected -air -Flow -Value changed -air -flow -value Next a correction map is created by storing, for each couple of values of the function F and of the engine load, a correction value Vcorrectjon given by the following equation: -(Texpected -Tmeauted) correction T 1expected These steps are repeated for the other parameters with the difference that when the parameter taken into consideration is the expected quantity of fuel of the PRE injection the corresponding correction map is created by storing the correction value Vcorrectjon, for each couple of values of the function F and of the engine speed.
When the parameters are the angle of the crankcase at which the PRE injection starts (PRE SQl), the angle of the crankcase at which the MAIN injection starts (MPJN SOl), and the intake air temperature, the function F is given by the following equation: F (Expected parameter value -changed parameter value) wherein the changed parameter value is measured or determined by known means, e.g. by the ECU.
When considering as parameters the angle of the crankcase at which the PRE injection starts (PRE SQl), the angle of the crankcase at which the MAIN injection starts (MAIN SOl), and the intake air terrperature, the correction map is created by storing the correction value Vcorrectjon, for each couple of values of the function F and of the engine speed.
Once a correction map for each parameter influencing the combustion chamber temperature has been created, the correction values are used to correct the mapped expected temperature in function of each couple of values of engine speed and engine load.
According to the invention the estimated temperature of the combustion chamber is given by the following equation: Texpecled J]' "correcgion (i) wherein i=l,...,n is the correction value corresponding to the parameter (1) kept into consideration.
While the present invention has been described with respect a certain preferred embodiment, it is understood that the description set forth herein above is to be taken by way of example and not of limitation.
Those skilled in the art will recognize that various modifications to the particular embodiment are within the scope of the appended claims. Therefore, it is intended that the invention not be limited to the disclosed embodiment, but that it has the full scope permitted by the language of the following claims.
Claims (11)
1. Method for the estimation of the mean temperature of the combustion chamber of an internal combustion engine comprising: a. experimentally creating at least a parameter map in which, in function of the engine speed and of the engine load, the value of one engine operation parameter influencing the temperature of the combustion chamber is measured; b. experimentally creating a temperature map in which the combustion chamber temperature is measured in function of the engine speed and of the engine load; c. experimentally change the value of said one operation parameter and measuring the temperature of the combustion chamber for each couple of values of engine speed and engine load of the parameter map; d. create a function F(changed parameter value, expected parameter value) for each couple of values of engine speed and engine load of the at least one parameter map associating the changed parameter value with the value of parameter stored in the parameter map; e. creating a correction map in which for each couple of values of the engine load, or engine speed, and of the function F(changed parameter value, expected parameter value) corresponds a correction parameter value expression of the variation of the expected temperature to the variation of the parameter; f. use the correction parameter values of said correction maps to determine an estimation of the combustion chamber temperature on the base of the combustion chamber expected temperature given by the temperature map in function of the speed load and the speed engine.
2. Method according to claim 1, wherein the engine operation parameter influencing the temperature of the combustion chamber is chosen from at least one of the following: intake air flow (IAF); pre injection fuel quantity (PRE); start of pre injection angle (PRE-SOl); angle of start of main injection (MAIN-SOl); intake air temperature is measured.
3. Method according to claim 1 and 2, wherein the function F(changed parameter value, expected parameter value) is equal to the division of the Expected parameter with the changed parameter when the parameter is intake air flow (IAF) or an injection pulses quantity.
4. Method according to claim 3, wherein the injection pulses quantity is a pre injection fuel quantity (PRE)
5. Method according to claim 1, wherein the function E'(changed parameter value, expected parameter value) is equal to the difference between the expected parameter and the changed parameter when the parameter is an injection pulses timing, an injection pulses angle, an intake air temperature.
6. Method according to claim 5, wherein the injection pulses timing is a time interval between the end of an injection pulse and the beginning of the next injection pulse (Dwell_Time), while the injection pulses angle is an angle of start of pre injection (PRE-SOl) or an angle of start of main injection (MAIN-SOl)
7. Method according to claim 1, wherein the correction parameter value, expression of the variation of the expected temperature to the variation of the parameter, is given by the equation: 1 v (Texpected -TmeUed) COITeCtrnfl T expected
8. Method according to claim 1, wherein the estimated temperature, for each couple of engine speed and engine load, is given by the equation: 2 0 xp ecled JJ Tcorreclion (i) wherein i=1,...,n is the correction value corresponding to the parameter (1) kept into consideration.
9. Method according to claim 1 in which a correction curve of the combustion chamber temperature given by the temperature map is created in function of the differences between the actual intake air temperature measured and of the intake air temperature given by the parameter map.
lO.Nethod according to claim 1 wherein the engine load is the quantity of fuel injected in the engine.
ll.Method according to claim 1 wherein the engine load is the value of torque required to the engine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0908748A GB2470389A (en) | 2009-05-21 | 2009-05-21 | Estimating of the mean temperature of the combustion chamber of an i.c. engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0908748A GB2470389A (en) | 2009-05-21 | 2009-05-21 | Estimating of the mean temperature of the combustion chamber of an i.c. engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB0908748D0 GB0908748D0 (en) | 2009-07-01 |
| GB2470389A true GB2470389A (en) | 2010-11-24 |
Family
ID=40862750
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0908748A Withdrawn GB2470389A (en) | 2009-05-21 | 2009-05-21 | Estimating of the mean temperature of the combustion chamber of an i.c. engine |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2470389A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114776457A (en) * | 2021-07-15 | 2022-07-22 | 长城汽车股份有限公司 | Engine oil injection control method and device, electronic equipment and vehicle |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4667630A (en) * | 1984-12-07 | 1987-05-26 | Toyota Jidosha Kabushiki Kaisha | Fuel evaporation rate control system for a direct fuel injection type internal combustion engine |
-
2009
- 2009-05-21 GB GB0908748A patent/GB2470389A/en not_active Withdrawn
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4667630A (en) * | 1984-12-07 | 1987-05-26 | Toyota Jidosha Kabushiki Kaisha | Fuel evaporation rate control system for a direct fuel injection type internal combustion engine |
Also Published As
| Publication number | Publication date |
|---|---|
| GB0908748D0 (en) | 2009-07-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7275426B2 (en) | Internal combustion engine control system | |
| KR100732892B1 (en) | Device and method for controlling internal combustion engine | |
| US8046156B2 (en) | Control apparatus of internal combustion engine | |
| EP2136057B1 (en) | Fuel quality dependent injection timing control for an internal combustion engine | |
| US20120095668A1 (en) | Method for feed-forward controlling fuel injection into a cylinder of an internal combustion engine | |
| JP6424747B2 (en) | Control system of diesel engine | |
| US8375776B2 (en) | Method for determining an in-cylinder pressure curve of a multi-cylinder engine | |
| RU2710144C2 (en) | Method (embodiments) and system for supplying fuel to engine | |
| US20110172898A1 (en) | Internal combustion engine system control device | |
| US9677525B2 (en) | Method of determining the injection pattern in the compression stroke of the combustion cycle of the cylinders of a direct-injection internal combustion engine | |
| US8731803B2 (en) | System and method to estimate intake charge temperature for internal combustion engines | |
| RU2670551C2 (en) | Method for feedback error learning in nonlinear systems (versions) | |
| RU2704909C2 (en) | System and method for adjusting exhaust valve timing | |
| JP6551317B2 (en) | Exhaust temperature estimation device for internal combustion engine | |
| US10563598B2 (en) | Engine operating system and method | |
| GB2470389A (en) | Estimating of the mean temperature of the combustion chamber of an i.c. engine | |
| Ingesson et al. | Efficiency optimal, maximum-pressure control in compression-ignition engines | |
| US8296040B2 (en) | Method for controlling an internal combustion engine with a temperature-dependent injection parameter | |
| WO2017086189A1 (en) | Engine fuel injection control device | |
| JP2014206070A (en) | Fuel injection control device for internal combustion engine | |
| JP6327586B2 (en) | Engine fuel injection control device | |
| JP4892460B2 (en) | Air quantity estimation device for internal combustion engine | |
| JP6414492B2 (en) | Diesel engine control device | |
| GB2478647A (en) | Method of Controlling the Combustion of an Internal Combustion Engine | |
| JP2010007607A (en) | Control device of multi-cylinder internal combustion engine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |