Engine control apparatus

• US 5,058,552 A
• Filed: 03/21/1990
• Issued: 10/22/1991
• Est. Priority Date: 06/08/1988
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Okubo, Satoru, Nishimura, Yukinobu, Wataya, Seiji, Shimomura, Setsuhiro
• Primary Examiner(s): Argenbright, Tony M.
• Assistant Examiner(s): Mates, Robert E.
• Application Number:
  US07/497,056
• Time in Patent Office: 580 Days
• Field of Search: 123/419, 123/425, 123/435, 123/436, 123/440, 123/489
• US Class Current: 123/406.23
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02D 35/023 by determining the cylinder pressure
• CPC Class Codes: F02D 37/02 one of the functions being ignition
• CPC Class Codes: F02D 41/1406 with use of a optimisation method, e.g. iteration
• CPC Class Codes: F02P 5/045 combined with electronic control of other engine functions, e.g. fuel injection in general F02D37/02
• CPC Class Codes: F02P 5/153 dependent on combustion pressure
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An engine control apparatus is provided with a control unit in which a fuel supply quantity Q_f or a ignition timing θ_i is corrected to maximize an evaluation parameter A=P_i /(Q_a /N) obtained on the basis of a suction air quantity Q_a, an engine speed N and a mean effective pressure P_i in a engine, or to maximize a parameter B=P_i /P_b obtained on the basis of a suction pipe pressure P_b and the mean effective pressure P_i, or to maximize a maximum pressure P_max or a mean effective pressure P_i for every combustion cycle, so that control is performed on the basis of the result of the above correction. The control unit also performs feedback control of the fuel supply quantity Q_f and corrects the ignition timing. Further, the control unit performs feedback control in a predetermined load-operation range of the engine, and stops the feedback control and corrects the fuel supply quantity Q_f out of said predetermined load-operation range of the engine.

Claims

1. An internal combustion engine control apparatus for an individual engine comprising:

an air-flow meter for measuring a suction air quantity Q_a of an engine;

a suction pipe pressure sensor for detecting suction pipe pressure P_b of said engine;

a crank angle sensor for detecting the revolution angle θ

_c of said engine;

at least one cylinder internal pressure sensor for detecting combustion chamber pressure P_c of said engine; and

a control unit which comprises;

means for obtaining a fuel supply quantity Q_f and an ignition timing θ

_i from an engine speed N and one of said suction air quantity Q_a and said suction pipe pressure P_b ;

means for obtaining at least one of maximum pressure value P_MAX for said individual engine, a mean effective pressure P_i, a first evaluation parameter A=P_i /(Q_a /N) and a second evaluation parameter B=P_i /P_b, said maximum pressure P_MAX and said mean effective pressure P_i being calculated from said combustion chamber pressure P_c and said revolution angle θ

_c for every combustion cycle, said first evaluation parameter A being calculated from said suction air quantity Q_a, said engine speed N and said mean effective pressure P_i, said second evaluation parameter B being calculated from said suction pipe pressure P_b and said mean effective pressure P_i ; and

means for correcting at least one of said fuel supply quantity l_f and said ignition timing θ

_i to maximize said at least one of said maximum pressure value P_MAX, said mean effective pressure P_i, and said first and second evaluation parameters A and B for said individual engine;

said apparatus further comprising;

means for controlling one of a fuel supply quantity and an ignition timing on the basis of a corrected value obtained from said correcting means; and

an exhaust sensor for detecting the component concentration of a combustion gas;

wherein said control unit further comprises means for obtaining an air-fuel ratio based on the component concentration of the combustion gas detected by said exhaust sensor, and means for performing a feedback control of said fuel supply quantity l_r to set said air-fuel ratio to a predetermined value; and

wherein said correcting means corrects said ignition timing θ

_i to maximize said at least one of said maximum pressure value P_MAX, said mean effective pressure P_i, and said first and second evaluation parameters A and B.

2. An internal combustion engine control apparatus comprising:

an air-flow meter for measuring a suction air quantity Q_a of an engine;

a suction pipe pressure sensor for detecting suction pipe pressure P_b of said engine;

a crank angle sensor for detecting the revolution angle θ

_c of said engine;

at least one cylinder internal pressure sensor for detecting combustion chamber pressure P_c of said engine; and

a control unit which comprises;

means for obtaining a fuel supply quantity Q_f and an ignition timing θ

_i from an engine speed N and one of said suction air quantity Q_a and said suction pipe pressure P_b ;

means for obtaining at least one of maximum pressure value P_MAX, a mean effective pressure P_i, a first evaluation parameter A=P_i /Q_a /N) and a second evaluation parameter B=P_i /P_b, said maximum pressure P_max and said effective pressure P_i being calculated from said combustion chamber pressure P_c and said revolution angle θ

_c for every combustion cycle, said first evaluation parameter A being calculated from said suction air quantity Q_a, said engine speed N and said mean effective pressure P_i, said second evaluation parameter B being calculated from said suction pipe pressure P_b and said mean effective pressure P_i ; and

means for correcting at least one of said fuel supply quantity l_f and said ignition timing θ

_i to maximize said at least one of said mean effective pressure P_i, said first evaluation parameter A and said second evaluation parameter B; and

means for controlling one of a fuel supply quantity and an ignition timing on the basis of a corrected value obtained from said correcting means.

3. An internal combustion engine control apparatus comprising:

an air-flow meter for measuring a suction air quantity Q_a of an engine;

a suction pipe pressure sensor for detecting suction pipe pressure P_b of said engine;

a crank angle sensor for detecting the revolution angle θ

_c of said engine;

at least one cylinder internal pressure sensor for detecting combustion chamber pressure P_c of said engine; and

a control unit which comprises;

means for obtaining a fuel supply quantity Q_f and an ignition timing θ

_i from an engine speed N and one of said suction air quantity Q_a and said suction pipe pressure P_b ;

means for obtaining maximum pressure value P_max, and at least one of a mean effective pressure P_i, a first evaluation parameter A=P_i (Q_a /N) and a second evaluation parameter B=P_i /P_b, said maximum pressure P_max and said mean effective pressure P_i being calculated from said combustion chamber pressure P_c and said revolution angle θ

_c for every combustion cycle, said first evaluation parameter A being calculated from said suction air quantity Q_a, said engine speed N and said mean effective pressure P_i, said second evaluation parameter B being calculated from said suction pipe pressure P_b and said mean effective pressure P_i ; and

means for correcting at least one of said fuel supply quantity l_f and said ignition timing θ

_i to maximize P_max and at least one of said mean effective pressure P_i, said first evaluation parameter A and said second evaluation parameter B; and

means for controlling one of a fuel supply quantity and an ignition timing on the basis of a corrected value obtained from said correcting means.