Back to results
US 2013/0340716 A1Published application
Closed loop control fuel injection method
AssigneeHyundai Motor Company
InventorChangyeol Choi
Life of this patent
Estimating the term…
Abstract
A closed loop control fuel injection method allows an injection amount and injection timing to be obtained, in such a way that an HRR (Heat Release Rate) is calculated from a combustion pressure signal of a combustion pressure sensor after a related pilot fuel amount is injected in a state in which an engine is warmed up, and to be adjusted according to command values, thereby removing inaccuracy of closed loop calibration and risks due to the excess of EM control caused when simply using a combustion pressure diagram, through predefined stable conditions.
Claims9
A closed loop control fuel injection method comprising:
- performing closed loop control of injector fuel injection classified into pilot injection and main injection if it is determined that an engine is a warm-up state and a fuel cut state, wherein the performing closed loop control of injector fuel injection comprises:
- performing the pilot injection wherein a fuel amount related to the pilot injection of the fuel injection is injected, an HRR (Heat Release Rate) together with a combustion pressure diagram are calculated by a combustion pressure signal detected from a combustion pressure sensor in a state of classifying rail pressures into a plurality of stages, an HRR height (H), an injection amount, and injection timing, which are obtained from the HRR, are compared with target values, and the HRR height (H), the injection amount, and the injection timing are controlled to be increased or decreased according to the target values;
- and
- performing the main injection, when the conditions of the pilot injection are released, wherein an HRR together with a combustion pressure diagram are calculated by a combustion pressure signal detected from a combustion pressure sensor in a state of classifying rail pressures into a plurality of stages, an HRR height (H), an injection amount, and injection timing, which are obtained from the HRR, are compared with target values, and the HRR height (H), the injection amount, and the injection timing are controlled to be increased or decreased according to the target values.
1 more element
A closed loop control fuel injection method comprising:
- identifying conditions so that closed loop control conditions of injector fuel injection classified into pilot injection and main injection are determined in a state in which an engine is a warm-up state and a fuel cut state;
- preparing pilot control so that, if the closed loop control conditions are satisfied, a fuel amount related to the pilot injection is injected, a combustion pressure diagram is calculated from a combustion pressure signal of a combustion pressure sensor with respect to a first rail pressure classified into a plurality of stages, an HRR diagram is derived from the combustion pressure signal, and a first HRR height (H), a first injection amount, and a first injection timing are calculated from the same;
- determining pilot control so that, under the same conditions, a second rail pressure, a second HRR height, a second injection amount, and second injection timing, which are increased or decreased values of the first rail pressure, the first HRR height (H), the first injection amount, and the first injection timing, respectively, are calculated, and the values are compared with reference values (ref) according to engine RPM and an engine load;
- executing pilot control so that the second HRR height, the second injection amount, and the second injection timing are increased or decreased and calibrated to correspond to the reference values (ref) so as to determine target values, and the closed loop control is performed according to the target values;
- changing injection so that if rail pressures checked when pilot injection close loop control is executed exceed a set maximum rail pressure, the pilot injection is stopped and main injection close loop control is executed;
- preparing main control so that, if the main injection close loop control is executed, a fuel amount related to the main injection is injected, a combustion pressure diagram is calculated from a combustion pressure signal of a combustion pressure sensor with respect to a new first rail pressure classified into a plurality of stages, an HRR diagram is derived from the combustion pressure signal, and a new first HRR height (H), a new first injection amount, and new first injection timing are calculated from the same;
- determining main control so that, under the same conditions, a new second rail pressure, a new second HRR height, a new second injection amount, and new second injection timing, which are increased or decreased values of the new first rail pressure, the new first HRR height (H), the new first injection amount, and the new first injection timing, respectively, are calculated, and the values are compared with new reference values (ref) according to engine RPM and an engine load;
- and
- executing main control so that the new second HRR height, the new second injection amount, and the new second injection timing are increased or decreased and calibrated to correspond to the new reference values (ref) so as to determine target values, and the closed loop control is performed according to the target values.
6 more elements
Dependencies are inferred from the claim text.