Abstract: Methods and systems are provided for adjusting an anticipatory controller of an exhaust gas sensor coupled in an engine exhaust. In one embodiment, the method comprises adjusting fuel injection responsive to exhaust oxygen feedback from the anticipatory controller of the exhaust gas sensor and adjusting one or more parameters of the anticipatory controller responsive to a type of oxygen sensor degradation. In this way, the anticipatory controller may be adapted based on the type and magnitude of the degradation behavior to increase performance of the air-fuel control system.

Abstract: A method for monitoring an exhaust gas sensor coupled in an engine exhaust is provided. In one embodiment, the method comprises indicating exhaust gas sensor degradation based on shape of a distribution of extreme values of a plurality of sets of lambda differentials collected during selected operating conditions. In this way, the exhaust gas sensor may be monitored in a non-intrusive manner.

Abstract: A method for monitoring an exhaust gas sensor coupled in an engine exhaust is provided. In one embodiment, the method comprises indicating exhaust gas sensor degradation based on characteristics of a distribution of extreme values of a plurality of sets of lambda differentials collected during selected operating conditions. In this way, the exhaust gas sensor may be monitored in a non-intrusive manner.

Abstract: A method of monitoring an exhaust gas sensor coupled in an engine exhaust is provided. The method comprises indicating exhaust gas sensor degradation based on a difference between a first set of estimated parameters of a rich operation model and a second set of estimated parameters of a lean operation model, the estimated parameters based on commanded lambda and determined lambda values collected during selected operating conditions. In this way, sensor degradation may be indicated with data collected in a non-intrusive manner.

Abstract: Methods and systems are provided reusing processed sensor data to identify multiple types of sensor degradation. In one example, a central peak of a distribution, such as a generalized extreme value distribution, of sensor readings is re-used to identify asymmetric sensor degradation and stuck in-range sensor degradation.

Abstract: Methods and systems are provided for converting an asymmetric degradation response of an exhaust gas sensor to a more symmetric degradation response. In one example, a method includes adjusting fuel injection responsive to a modified exhaust oxygen feedback signal from an exhaust gas sensor, the modified exhaust oxygen feedback signal modified by transforming an asymmetric response of the exhaust gas sensor to a more symmetric response. Further, the method may include adjusting one or more parameters of an anticipatory controller of the exhaust gas sensor based on the modified symmetric response.

Abstract: Methods and systems are provided for adjusting an anticipatory controller of an exhaust gas sensor coupled in an engine exhaust. In one embodiment, the method comprises adjusting fuel injection responsive to exhaust oxygen feedback from the anticipatory controller of the exhaust gas sensor and adjusting one or more parameters of the anticipatory controller responsive to a type of oxygen sensor degradation. In this way, the anticipatory controller may be adapted based on the type and magnitude of the degradation behavior to increase performance of the air-fuel control system.

Abstract: A method of monitoring an exhaust gas sensor coupled in an engine exhaust is provided. The method comprises indicating exhaust gas sensor degradation based on a difference between a first set of estimated parameters of a rich operation model and a second set of estimated parameters of a lean operation model, the estimated parameters based on commanded lambda and determined lambda values collected during selected operating conditions. In this way, sensor degradation may be indicated with data collected in a non-intrusive manner.

Abstract: A method for monitoring an exhaust gas sensor coupled in an engine exhaust is provided. In one embodiment, the method comprises indicating exhaust gas sensor degradation based on characteristics of a distribution of extreme values of a plurality of sets of lambda differentials collected during selected operating conditions. In this way, the exhaust gas sensor may be monitored in a non-intrusive manner.