Air/fuel mixture ratio control system for internal combustion engine with feature of learning correction coefficient including altitude dependent factor

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EP 0 292 973 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	27.09.1989 Bulletin 1989/39

(43)	Date of publication A2:
	30.11.1988 Bulletin 1988/48

(21)	Application number: 88108437.0

(22)	Date of filing: 26.05.1988

(51)	International Patent Classification (IPC)⁴: F02D 41/14, F02D 41/04, F02D 41/34, F02D 41/26

(84)	Designated Contracting States:
	DE GB

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Priority:

28.05.1987 JP 129893/87
29.05.1987 JP 131826/87

(60)	Divisional application:
	91111421.3 / 0452996

(71)	Applicant: JAPAN ELECTRONIC CONTROL SYSTEMS CO., LTD.
	Isesaki-shi Gunma-ken, 372 (JP)

(72)	Inventor:
	Tomisawa, Naoki Japan Elec.Contr.Syst.Co.,Ltd. Gunma-ken 372 (JP)

(74)	Representative: Schoppe, Fritz, Dipl.-Ing.
	Patentanwalt, Georg-Kalb-Strasse 9 82049 Pullach 82049 Pullach (DE)

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References cited: :

(54)	Air/fuel mixture ratio control system for internal combustion engine with feature of learning correction coefficient including altitude dependent factor

(57) An air/fuel ratio control system controls fuel delivery amount on the basis of oxygen concentration in an exhaust gas. An air/fuel ratio dependent correction value is derived on the basis of the oxygen concentration. The air/fuel ratio control is performed in feedback mode and open loop mode. In feedback mode, fuel delivery amount is corrected utilizing a correction value which includes a learnt component. Learning of the learnt component is performed during feedback mode operation. The learnt component comprises an uniformly applicable air density dependent factor and a engine driving range dependent factor which is set with respect to each of the engine driving ranges. Learning of the air density factor and engine driving range dependent factor are selectively performed depending upon the engine driving condition.

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