Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N5/00—Systems for controlling combustion
  • F23N5/003—Systems for controlling combustion using detectors sensitive to combustion gas properties
  • F23N5/006—Systems for controlling combustion using detectors sensitive to combustion gas properties the detector being sensitive to oxygen
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
  • F02C9/00—Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants
  • F02C9/26—Control of fuel supply
  • F02C9/40—Control of fuel supply specially adapted to the use of a special fuel or a plurality of fuels
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
  • F02D19/06—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed
  • F02D19/0602—Control of components of the fuel supply system
  • F02D19/0607—Control of components of the fuel supply system to adjust the fuel mass or volume flow
  • F02D19/061—Control of components of the fuel supply system to adjust the fuel mass or volume flow by controlling fuel injectors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
  • F02D19/06—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed
  • F02D19/0602—Control of components of the fuel supply system
  • F02D19/0613—Switch-over from one fuel to another
  • F02D19/0615—Switch-over from one fuel to another being initiated by automatic means, e.g. based on engine or vehicle operating conditions
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
  • F02D19/06—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed
  • F02D19/0626—Measuring or estimating parameters related to the fuel supply system
  • F02D19/0628—Determining the fuel pressure, temperature or flow, the fuel tank fill level or a valve position
  • F02D19/0631—Determining the fuel pressure, temperature or flow, the fuel tank fill level or a valve position by estimation, i.e. without using direct measurements of a corresponding sensor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
  • F02D19/06—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed
  • F02D19/0639—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed characterised by the type of fuels
  • F02D19/0642—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed characterised by the type of fuels at least one fuel being gaseous, the other fuels being gaseous or liquid at standard conditions
  • F02D19/0647—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed characterised by the type of fuels at least one fuel being gaseous, the other fuels being gaseous or liquid at standard conditions the gaseous fuel being liquefied petroleum gas [LPG], liquefied natural gas [LNG], compressed natural gas [CNG] or dimethyl ether [DME]
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
  • F02D19/06—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed
  • F02D19/0663—Details on the fuel supply system, e.g. tanks, valves, pipes, pumps, rails, injectors or mixers
  • F02D19/0686—Injectors
  • F02D19/0692—Arrangement of multiple injectors per combustion chamber
• • 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
  • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
• • 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
  • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
  • F02D41/0027—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures the fuel being gaseous
• • 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
  • F02D41/24—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means
  • F02D41/26—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means using computer, e.g. microprocessor
  • F02D41/266—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means using computer, e.g. microprocessor the computer being backed-up or assisted by another circuit, e.g. analogue
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B1/00—Engines characterised by fuel-air mixture compression
  • F02B1/02—Engines characterised by fuel-air mixture compression with positive ignition
  • F02B1/04—Engines characterised by fuel-air mixture compression with positive ignition with fuel-air mixture admission into cylinder
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2400/00—Control systems adapted for specific engine types; Special features of engine control systems not otherwise provided for; Power supply, connectors or cabling for engine control systems
  • F02D2400/11—After-sales modification devices designed to be used to modify an engine afterwards
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N1/00—Regulating fuel supply
  • F23N1/04—Regulating fuel supply conjointly with air supply and with draught
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N2223/00—Signal processing; Details thereof
  • F23N2223/04—Memory
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N2223/00—Signal processing; Details thereof
  • F23N2223/08—Microprocessor; Microcomputer
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N2237/00—Controlling
  • F23N2237/08—Controlling two or more different types of fuel simultaneously
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/30—Use of alternative fuels, e.g. biofuels

Definitions

• the invention relates to a system, method and electronic control unit for the metered supply of at least a first and a second type of fuel, in particular petrol and LPG (Liquid Petroleum Gas), to a combustion installation, such as an internal combustion engine, turbine, furnace or the like.
• a combustion installation such as an internal combustion engine, turbine, furnace or the like.
• the invention also relates to an internal combustion engine provided with such a system and control unit.
• Combustion installations which operate on more than one type of fuel, whereby the fuel, such as internal combustion engines, whereby the fuel supply is controlled by means of an electrical/electronic control unit are known per se in practice.
• the differences in energy content of the fuels concerned, which necessitate adapted metering, constitute a problem to be solved with such installations.
• Netherlands Patent Application 82.00993 describes a system for the metered supply of petrol and/or LPG to an internal combustion engine with the aid of time-controlled fuel injectors.
• a mutually correct mechanical calibration of the petrol and LPG injectors used enables both types of injectors to be controlled by the same electronic control unit, which controls the duration and frequency of opening of the injectors, over the entire power and speed range of the engine.
• Both systems have a facility for adapting the duration of opening of the injectors to a changing composition of the fuel, in which context consideration can be given to, for example, winter and summer composition of LPG, as a consequence of which the calorific value and the required amount of air per unit volume of fuel injected are not constant. It has been found that this method of metering of the types of fuel is not optimum, which can be appreciated as follows.
• control units used for internal combustion engines have adaptive control characteristics. That is to say, the control unit is configured in such a way that it adjusts automatically to a change in the demand for fuel owing to, for example, wear, play or other causes in the engine, so as to be able to deliver performances comparable to those obtained when the engine is without defect. If an engine is run for a prolonged period on a first type of fuel, for example petrol, the control strategy of the control unit will have been optimally adjusted for petrol metering.
• a first type of fuel for example petrol
• the objective on which the invention is based is, therefore, firstly to indicate a system, method and control unit for a combustion installation, operating on an original or first type of fuel, for the metered supply of an alternative or second type of fuel in such a way that the original or first electronic control unit used for metering the first fuel can be used to control the metering of the alternative or second fuel, without, however, the control strategy developed by said first control unit being adjusted outside the operating range for the first fuel.
• a system which comprises a first electronic control unit for metering, via fuel supply means, the supply of the first and second fuel, and detection means for the detection of process and operating parameter values of the combustion installation, characterised by a second electronic control unit, coupled to the first control unit and the fuel supply means, for metering the supply of the second fuel under the control of the first control unit, said second control unit comprising recording means for, during operation on the first fuel, recording, as a function of respective detected process and operating parameter values, first control signal values emitted by the first control unit and control and comparison means for, during operation on the second fuel, comparing, in dependence of the process and operating parameters concerned, the momentorily emitted first control signal values with the first control signal values recorded by the recording means, in order so to adjust second control signal values emitted by the second control unit that the momentarily emitted first control signal values are kept within a predetermined range with respect to the recorded first control signal values.
• the invention is based on the concept of also making the conversion of the metering by means of the second electronic control unit adaptive and specifically of doing so in such a way that, during operation on the second fuel, deviations in the control strategy of the first control unit which fall outside a predetermined range are detected and brought back within said range by adjusting the metering of the second fuel.
• this is achieved in that the control strategy developed by the first control unit during operation on the first fuel is stored in suitable recording means of the second control unit.
• any deviation herein as a consequence of the adaptive behaviour of the first control unit during use of the second fuel can be corrected immediately by suitable adjustment of the metering of the second fuel.
• the first control unit develops a control strategy during operation on the second fuel which differs from that developed for operation on the original first fuel can be effectively prevented.
• the control strategy of the first control unit can consequently be held at the correct operating point for metering of the first fuel, so that on switching to the first or original fuel a default program will not be started and no losses of performance or additional environmental pollution worthy of note will occur and damage to system components is prevented.
• the system according to the invention is therefore particularly suitable for use in combustion installations which have to be operated on other types of fuel as an alternative for some period, for example in the internal combustion engine described above for the purposes of illustration.
• the first or original fuel is petrol and the alternative or second fuel is LPG
• the reverse can also be the case and that several types of second fuel can be used.
• the range within which a correction is made to the metering of the second fuel can, instead of being very narrow as indicated above, also be set so wide that some degree of adjustment in the control strategy is possible during operation on the second fuel.
• An average of the operating ranges of the first and second fuels can be considered in this context.
• a further important advantage of the system according to the invention is that it can be used irrespective of the type of control unit, that is to say the control algorithm incorporated herein.
• a control strategy which has been developed is adopted dynamically by the second electronic control unit by means of recording of the relevant control signals.
• the second control unit comprises authorisation means for authorising the recording of first control signal values during operation on the first fuel depending on the detection of predetermined values of respective process and operating parameters.
• the authorisation means are arranged for authorising comparison, during operation on the second fuel, of the first control signal values momentarily emitted with the first control signal values recorded by the recording means, depending on the detection of the relevant predetermined values of respective process and operating parameters.
• the purpose of this further embodiment is to prevent undesired adjustments to the metering in response to control signal values during the initiation or start-up stage of a combustion process.
• the authorisation means are arranged to authorise the recording and/or comparison of the first control signal values during operation on the first and/or second fuel depending on a quasi-steady state of operation for the combustion installation determined from the respective process and operating parameters.
• efficient storage of control signal values is achieved in that the second control unit comprises further comparison means, which are coupled to the recording means, for recording, during operation on the first fuel, only first control signal values which differ from the first control signal values already stored.
• the system according to the invention can be used either in combustion installations in which the various types of fuel are supplied via the same metering means and the second control unit then has to be provided with switching means which can be actuated to interrupt the control of the fuel supply means by the first control unit or in a system in which the various types of fuel are supplied to the combustion installation via individual fuel supply means, as is customary, for example, in internal combustion engines. .
• the system according to the invention is suitable for use of various types of fuel supply means, in particular time-controlled fuel injectors.
• fuel supply means in particular time-controlled fuel injectors.
• the system according to the invention is particularly suitable for rendering an existing combustion installation operating on an original or first fuel suitable for use with an alternative and second type of fuel, or for rendering combustion installations which have already been modified in this way suitable for application of the method according to the invention
• the first and second control units can, according to yet a further embodiment, be produced as a single integral unit. This is of interest in particular for newly manufactured combustion installations or for existing combustion installations which are provided with a new control system.
• the invention relates in particular to use in an internal combustion engine, the means for detecting process and operating parameter values at least comprising temperature, load and revolution count detectors as well as means for analysing the combustion emissions.
• Detectors suitable for this purpose are known per se in practice and nowadays form part of the normal known equipment for four-stroke Otto engines provided with petrol injection systems.
• the invention also provides an electronic control unit for use as the second control unit in a system for the metered supply, via fuel supply means, of the second fuel, in particular LPG, to a combustion installation, such as an internal combustion engine, turbine, furnace or the like, which operates on at least a first and a second type of fuel, said control unit comprising a digital processor unit provided with several inputs for supplying control signal values originating from an electronic control unit for metering the first fuel and detected process and operating parameter values from the combustion installation, and several outputs, for transmitting to the fuel supply means control signal values for metering the fuel supply, and recording means, coupled to the processor unit, for recording supplied control signal values in dependence of respective operating and process parameters, the processor unit being arranged to compare, in dependence of the process and operating parameters concerned, the control signal values momentarily supplied to the processor unit with the control signal values recorded by the recording means, in order so to adjust the control signal values emitted by the processor unit that the control signal values momentarily supplied are kept within a predetermined range with respect to the recorded control signal
• the processor unit is arranged to authorise the recording and/or comparison of the supplied control signal values depending on predetermined values of respective process and operating parameters and/or a quasi- steady state of operation of the combustion installation determined from the respective process and operating parameters.
• Suitable recording means comprise a so-called EEPROM (Electrically Erasable/Programmable Read Only Memory).
• FIG 1 shows, diagrammatically, the system according to the invention used in an internal combustion engine
• Figure 2 shows a block diagram of an electronic control unit for use in the system according to the invention.
• a combustion installation in the form of an internal combustion engine for example a four-stroke four-cylinder Otto engine, is shown in its entirety by reference numeral 1 and is provided with a combustion mixture inlet pipe 2 and an exhaust gas pipe 3.
• the internal combustion engine 1 has first or original fuel supply means 4, for example for the supply of petrol, and first fuel injectors 5, which are connected to said fuel supply means and by means of which the first fuel can be made up, together with air drawn in, in the inlet pipe 2 into a combustion mixture for the internal combustion engine 1.
• first or original fuel supply means 4 for example for the supply of petrol
• first fuel injectors 5 which are connected to said fuel supply means and by means of which the first fuel can be made up, together with air drawn in, in the inlet pipe 2 into a combustion mixture for the internal combustion engine 1.
• second fuel supply means 6 for example for the supply of LPG (Liquid Petroleum Gas), with associated second fuel injectors 7, are provided, by means of which, as an alternative to the first fuel, a second type of fuel can be mixed with air in the inlet pipe 2 to form a combustion mixture for the internal combustion engine 1.
• LPG Liquid Petroleum Gas
• a first or original electronic control unit 8 is provided for determination of the metering of the first fuel, which first control unit transmits first control signals to the fuel injectors 5 via a signal line 9.
• said first control signals comprise electrical pulses of a specific duration and repeat frequency, depending on detected process and operating parameter values for the internal combustion engine 1.
• detection means 10 in the form of temperature, load and revolution count detectors, are provided, as well as means 11 with which the composition of the exhaust gas can be analysed, for example a so- called lambda probe, which means are accommodated in the exhaust gas pipe 3.
• the data obtained from the detection means 10 and the feedback signal emitted by the means 11 are supplied to the first control unit 8, which, on the basis of these data, optionally in conjunction with data relating to the composition of the first fuel, develops a control strategy for optimum control of the combustion process in the internal combustion engine 1 within a particular operating range.
• a second electronic control unit 12 is connected via an input connection point 14 to the first control unit 8.
• Second control signals are transmitted to the second fuel injectors 7 by the second control unit 12 via one or more output connection points 13.
• switching means 18 are accommodated in the signal line 9 from the first control unit 8 to the first fuel injectors 5, which switching means can be actuated from an output connection point 17 by the second control unit 12.
• Mechanical switching means 18 are shown here merely by way of example so that the invention can be understood. Of course, semiconductor switching means can also be used for this purpose.
• valves, fuel pumps, pressure regulators, ignition means and the like needed to operate the internal combustion engine 1 are not included in the diagram in Figure 1.
• the first or original electronic control unit 8 is likewise a standard component in present day internal combustion engines operating with fuel injection.
• said control units have adaptive characteristics, that is to say that the metering strategy is adapted automatically to a changed demand for fuel as a consequence of changes which arise in the internal combustion engine 1 as a result of wear, play and the like and, if desired, also the combustion characteristics of the fuel supplied.
• FIG. 2 shows a block diagram of an embodiment of the second electronic control unit 12 according to the invention.
• the second control unit 12 contains a processor unit 19, which comprises a microprocessor and associated control components, an electrical power unit 23 for producing the necessary operating voltage(s) and recording or memory means 20 in the form of an EEPROM (Electrically Erasable/Programmable Read Only Memory).
• the processor unit 19 is provided with a number of input connection points
• the processor unit 19 also has a number of output connection points 13 for transmitting control signals to the fuel supply means, such as the second fuel injectors 7, and an output connection point 17 for controlling switching means 18.
• the processor unit 19 it can be necessary to incorporate amplifiers and/or analogue/digital or digital/analogue converters, which are designated in general by the reference numerals 21, 22, in the connection from the diverse input and output connection points, respectively, to the processor unit 19.
• the means designated by reference numeral 21 render the received signals suitable for processing by the processor unit 19, whilst the means 22 render the signals emitted by the processor unit 19 suitable for supplying to the various fuel injectors and the like.
• the memory unit 20 is configured in such a way that, on the basis of parameter values supplied to the input connection points 15, the associated first control signals, emitted by the first control unit 8, can be stored here digitally in table or matrix form.
• the processor unit 19 is, furthermore, so programmed that said unit is able to compare supplied first control signal values with stored first signal values, if desired on condition that predetermined parameter values apply, and suitably adjust the received first control signal values to produce second control signal values transmitted to the output connection points 13 for metering the supply of second fuel.
• the various features are organised such that, during operation on the second fuel, the first control signals momentarily received are kept within a predetermined range of the first control signal values stored in the memory means 20.
• the control unit 8 will, as a consequence of its adaptive mode of operation, develop a control strategy with which the internal combustion engine 1 will be operated in the optimum manner within its operating range.
• a first closed control circuit in the form of the first control unit 8, the first fuel injectors 5, the internal combustion engine 1 and the lambda probe 11 can be identified.
• the second control unit 12 operates to store the transmitted first control signal values in the recording or memory means 20 in dependence of the detected process and operating parameter values. In this context it is possible, for example, to use air mass and speed of revolutions as two operating parameter values along the axes of a two-dimensional table in the recording means 20 of the second control unit 12.
• the first control signals emitted by the first control unit 8 in the two-dimensional table, for example in a (quasi)-steady operating state (for which, depending on the application, a possible criterion could be: no changes greater than 10 % in process and operating parameter values over a period of 10 seconds), which state is determined by authorisation means.
• Specific control signal values can already be stored beforehand in the memory means.
• the processor unit 19 it is preferable to program the processor unit 19 in such a way that the only values still recorded are those with differ from the control signals already stored. In this way the memory means 20 always contain the most up-to-date control strategy of the first control unit 8.
• the second control unit 12 On switching to operation on the second type of fuel, by actuating the input connection point 16, the second control unit 12 activates the switching means 18 and, via the output connection points 13, transmits suitable second control signal values to the second fuel injectors 7, for example second control signal values which are suitable for the metering of LPG. All of this is under the control of the first control unit 8, which, via the detection means 10 and the lambda probe 11, determines the frequency and duration of the second control signal values emitted on the basis of the detected process and operating parameter values. In this case as well a closed control circuit can again be identified, namely the first control unit 8, the second control unit 12, the second fuel injectors 7, the internal combustion engine 1 and the lambda probe 11.
• the processor unit 19 is now operating in such a way that first control signals momentarily from the first control unit 8 are compared with the first control signal values stored under the same operating conditions in the memory means 20.
• the second control unit 12 can check, in a state of operation determined by authorisation means (such as, for example, the abovementioned (quasi)- steady state of operation), whether the first control signal values momentarily produced by the first control unit 8 correspond to the values recorded in the two-dimensional table under the said conditions (speed of revolutions and air mass).
• This check is carried out in order, in the event of a discrepancy falling outside a predetermined range, to adjust the metering of the second fuel, via the second control signals emitted, such that the first control signal values at the particular instant again agree with the corresponding stored first control signal values, at least to within the predetermined range.
• the result of this adaptive behaviour of the second control unit 12 is to prevent the control strategy of the first control unit 8 being so disturbed by the use of the second fuel that it ⁇ s brought outside the operating range for the first fuel.
• the control strategy of the first control unit 8 has not been brought outside the operating range for running the internal combustion engine 1 on the first fuel, there will be virtually no or a negligible loss of performance and fuel and virtually no or negligible additional environmental pollution as a result of an incorrect combustion process, which would be the case if the first control unit 8 were "disrupted" at the time of the switch ⁇ over. It is advisable to carry out the recording, comparison and adjustment of the conversion only when the internal combustion engine 1 is warm and the operating parameters load, speed of revolutions and the like are stable and preferably when the operating conditions are quasi-steady state. To this end, the processor unit 19 can be provided with a suitable authorisation procedure.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Computer Hardware Design (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
• Regulation And Control Of Combustion (AREA)
• Feeding And Controlling Fuel (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19862907

Family Applications (1)

Country Status (14)

Cited By (4)

Families Citing this family (40)

Citations (3)

Family Cites Families (4)

• 1993
  • 1993-09-21 NL NL9301635A patent/NL9301635A/nl not_active Application Discontinuation
• 1994
  • 1994-09-21 WO PCT/NL1994/000229 patent/WO1995008706A1/en not_active Ceased
  • 1994-09-21 EP EP95900324A patent/EP0720690B1/en not_active Expired - Lifetime
  • 1994-09-21 JP JP7509701A patent/JPH09505653A/ja not_active Ceased
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  • 1994-09-21 NZ NZ275898A patent/NZ275898A/en unknown
  • 1994-09-21 AU AU81179/94A patent/AU684853B2/en not_active Expired
  • 1994-09-21 US US08/617,926 patent/US5628294A/en not_active Expired - Lifetime
  • 1994-09-21 DK DK95900324.5T patent/DK0720690T3/da active
  • 1994-09-21 ES ES95900324T patent/ES2107291T3/es not_active Expired - Lifetime
  • 1994-09-21 CA CA002172290A patent/CA2172290C/en not_active Expired - Fee Related
  • 1994-09-21 DE DE69405400T patent/DE69405400T2/de not_active Expired - Fee Related
  • 1994-11-11 TW TW083110461A patent/TW289784B/zh active
• 1997
  • 1997-10-22 GR GR970402794T patent/GR3025161T3/el unknown

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