Robert Boschgmbh

Hans P Geering

Gerhard Heess

Eberhard Schnaibel

Anton Van Zanten

Erich Schneider

Helmut Schwarz

Rudiger Deibert

Esfandiar Shafai

Christian Roduner

The invention is directed to a method for adjusting the air/fuel ratio for an internal combustion engine having a catalytic converter connected downstream thereof which is capable of storing oxygen. In this method, the oxygen components in the exhaust gas of the engine are detected upstream of the catalytic converter and downstream thereof and the adjustment of the fuel/air ratio is influenced. In the method, a measure for the instantaneous oxygen fill level of the catalytic converter is determined from the above-mentioned oxygen components with the aid of a model. Data as to the state of deterioration of the catalytic converter are derived from the model parameters. The air/fuel ratio is so adjusted that the oxygen fill level of the catalytic converter is held to a constant mean level.

Method of adjusting the air/fuel ratio for an internal combustion engine

Method for ascertaining the set-point braking moment for the various

The invention is directed to a method for the formation of an air-fuel mixture for an internal combustion engine, including an oxygen sensor exposed to the exhaust gas and responsive to the oxygen content of the exhaust gas, a signal-processing unit processing the output signals of the oxygen sensor, and a memory store for storing a set of characteristic curves dependent on at least one operating parameter of the internal combustion engine, the characteristic values thereof (F.sub..lambda.) determining the amount of fuel to be metered. In this method, a time-variable perturbation (.DELTA.F.sub..+-.) is superposed on the characteristic values (F.sub..lambda.), the oxygen sensor output signals (U.sub..lambda.) are evaluated with regard to their change due to the perturbation (.DELTA.F.sub..+-.), and the characteristic values (F.sub..lambda.) are suitably corrected to achieve an optimum air-fuel ratio. In this arrangement, the modulation frequency of the characteristic values (F.sub..lambda.) is to assume as high values as possible while the modulation amplitude is to be as low as possible. This method permits a substantial increase in the limit frequency of the Lambda sensor operation cycles.

Method for Lambda control in an internal combustion engine

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Winterthur, Switzerland

Hans P Geering