Method for operating auto ignition combustion engine
First Claim
Patent Images
1. A method for operating auto ignition combustion engines, comprising:
- directly linking outputs to an injected fuel mass flow distribution and to an injection timing by taking into account engine out emissions and/or drivability constraints by using an optimization method,determining an optimized torque realization TQI_SP by minimizing an error of a multi-objective function for overall engine operating points, wherein the determined optimized torque realization is implemented by at least one engine actuator configured to control at least one of;
a number of injection Nbinj par combustion cycle,1≦
i≦
Nbinj where i is an index for different fuel injections relating to a large number of fuel injection patterns, such as i =1 for a first pre-injection, i=2 for a second pre-injection, etc.;
quantities injected per elementary injection MFi with Σ
iMFi=MF;
a start of injection SOIi per elementary injection;
an air path control by the way of the global equivalence ratio Φ
because in our case the measured air mass flow, MA, is linked to injected mass flow MF by Φ
=(MF/MA)*α
stoich;
a global equivalence ratio Φ
is set according to the engine load targets and the turbocharger air mass flow limitation for a given operating point; and
an EGR rate, XEGR=[burnt gases]./[fresh gases] defined as the ratio between burnt gases and fresh gases in the intake manifold.
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Abstract
A low computation method for operating auto ignition combustion engines, in which outputs, in particular a requested torque set point TQI_SP is directly linked to an injected fuel mass flow distribution, to the EGR rate and the air control by taking into account engine out emissions & drivability constrains by using a multi-objective optimization method. A method to monitor in the embedded controller the indicated torque, TQI is also proposed.
18 Citations
16 Claims
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1. A method for operating auto ignition combustion engines, comprising:
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directly linking outputs to an injected fuel mass flow distribution and to an injection timing by taking into account engine out emissions and/or drivability constraints by using an optimization method, determining an optimized torque realization TQI_SP by minimizing an error of a multi-objective function for overall engine operating points, wherein the determined optimized torque realization is implemented by at least one engine actuator configured to control at least one of; a number of injection Nbinj par combustion cycle,1≦
i≦
Nbinj where i is an index for different fuel injections relating to a large number of fuel injection patterns, such as i =1 for a first pre-injection, i=2 for a second pre-injection, etc.;quantities injected per elementary injection MFi with Σ
iMFi=MF;a start of injection SOIi per elementary injection; an air path control by the way of the global equivalence ratio Φ
because in our case the measured air mass flow, MA, is linked to injected mass flow MF by Φ
=(MF/MA)*α
stoich;
a global equivalence ratio Φ
is set according to the engine load targets and the turbocharger air mass flow limitation for a given operating point; andan EGR rate, XEGR=[burnt gases]./[fresh gases] defined as the ratio between burnt gases and fresh gases in the intake manifold.
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2. A method for operating auto ignition combustion engines, comprising:
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directly linking a requested torque set point TQI SP and an estimation of a torque realization TQI to an injected fuel mass flow distribution and to an injection timing by taking into account engine out emissions and/or drivability constraints by using an optimization method, and calculating by a processor the torque realization TQI as a function of at least (a) MF;
a fuel mass injected per combustion cycle [g/stroke] dedicated to torque production, (b) LHV;
a fuel combustion lowest heating value [J/g], (c) N;
an engine speed, and (d) η
;
a global fuel to torque conversion efficiency. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for operating auto ignition combustion engines, comprising:
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directly linking outputs to an injected fuel mass flow distribution and to an injection timing by taking into account engine out emissions and/or drivability constraints by using an optimization method, and using a global equivalence ratio Φ
=(MF/MA)/(MF/MA)stoich =(MF/MA)*α
stoich to adapt an air mass flow via an air path control and turbocharger position control,wherein MA represents an air mass flow, MF represents an injected fuel mass.
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14. A method for operating auto ignition combustion engines, comprising:
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directly linking outputs to an injected fuel mass flow distribution and to an injection timing by taking into account engine out emissions and/or drivability constraints by using an optimization method, and wherein an overall fuel mass injected in a combustion chamber for lean combustion is burnt during the auto-ignition process with the start of injections SOI being calibrated to compensate the injector response, the auto ignition delay, and the EGR effect on the auto ignition delay, such that the combustion efficiency variation η
comb is ignored and fixed to η
comb =1, at least for a selected SOI bandwidth that respects engine out emission constrains.
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15. A method for operating auto ignition combustion engines, comprising:
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directly linking outputs to an injected fuel mass flow distribution and to an injection timing by taking into account engine out emissions and/or drivability constraints by using an optimization method, and wherein a mechanical efficiency η
mech is used in an embedded software as a 2D look up table depending both on the engine speed N and the engine cooling temperature TCO,η
mech=η
mech(N,TCO).
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16. A method for operating auto ignition combustion engines, comprising:
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directly linking a requested torque set point TQI_SP and an estimation of a torque realization TQI to an injection timing by taking into account engine out emissions and/or drivability constraints by using an optimization method, and determining an optimized torque realization TQI_SP by minimizing an error of a multi-objective function J for overall engine operating points, using the function;
J=WTQI— SP*TQI—
SP/TQI—
SPref+Wsoot*[Soot]/[Soot]ref+Wnox*[Nox]/[Nox]ref+Wco2* [CO2]/[CO2]ref+WHC*[HC]/[HC]ref+WCO*[CO]/[CO]ref+Wnoise*[Noise]/[Noise]ref and where;
TQI_SP ref is the targeted indicated torque in Nm; [Soot]ref is the targeted soot emission value in g/stroke or g/km; [Nox]ref is the targeted nitrogen oxides emission value in g/stroke or g/km; [CO2] ref is the targeted carbon dioxide emission value in g/stroke or g/km; [HC] ref is the targeted unburnt hydrocarbons emission value in g/stroke or g/km; [CO] ref is the targeted carbon monoxide emission value in g/stroke or g/km; [Noise] ref is the targeted noise limitation in DbA or bar/s; and Wk is a weight of each respective objective k.
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Specification