31results about How to "Reduced vehicle drivability" patented technology

A method for determining degradation of an exhaust gas sensor positioned in an exhaust system for an internal combustion engine of a vehicle is provided. The method includes modulating an air / fuel ratio of gas exhausted by the internal combustion engine to the exhaust system through a cycle that includes at least one rich-to-lean transition and at least one lean-to-rich transition, indicating a degradation condition of the exhaust gas sensor in response to at least one of a rich-to-lean response duration of the exhaust gas sensor and a lean-to-rich response duration of the exhaust gas sensor being greater than a delay threshold, and indicating the degradation condition of the exhaust gas sensor in response to a ratio of the rich-to-lean response duration to the lean-to-rich response duration being greater than an asymmetry threshold that is relative to an axis of symmetry of the rich-to-lean response duration versus the lean-to-rich response duration.

A vehicle propulsion system and method of operation are presented. As one example, the method includes operating an engine to produce an engine output; transferring the engine output to one or more drive wheels of the vehicle via a transmission; responsive to a first condition, varying torque supplied to the drive wheels by adjusting a relative number of combusting cylinders and deactivated cylinders of the engine; and responsive to a second condition, varying the torque supplied to the drive wheels by adjusting a number of strokes performed by the combusting cylinders per combustion cycle while shifting the transmission between different gear ratios.

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.

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 a time delay and line length of each sample of a set of exhaust gas sensor responses collected during a commanded change in air-fuel ratio. In this way, the exhaust gas sensor may be monitored utilizing robust parameters in a non-intrusive manner.

A vehicle control system is provided. The vehicle control system is applied to a vehicle having a clutch device to selectively connect and disconnect a power transmission route between a prime mover and drive wheels, and configured to disconnect the power transmission route during running to allow the vehicle to coast. The vehicle control system is comprised of: a means that detects a vehicle speed; a means that detects an operation of an accelerator by a driver; an execution means that executes a coasting control when an operating amount of an accelerator is reduced to be smaller than a predetermined value during running, by bringing the clutch device into disengagement to disconnect the power transmission route so as to allow the vehicle to coast; an estimation means that estimates a decelerating demand of the driver during execution of the coasting control; and a returning means that terminates the coasting control by bringing the clutch device into engagement to connect the power transmission route, and that increases a speed ratio of the automatic transmission when the decelerating demand is expected to increase.

Systems and methods for monitoring an exhaust gas sensor coupled in an engine exhaust are provided. In one example approach, a method comprises indicating exhaust gas sensor degradation based on a downstream exhaust gas sensor responding before the upstream exhaust gas sensor during a commanded change in air-fuel ratio.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, a position of an engine air intake throttle is adjusted during cylinder deactivation to control intake manifold pressure for cylinder reactivation. Closing of the throttle may be timed based on an actual total number of cylinder induction events expected to provide a desired engine intake manifold pressure.

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.

A multi-mode internal combustion engine is described. As one example, the engine may be transitioned between a two stroke mode and a four stroke mode in coordination with a transmission shift by adjusting a number of strokes performed by the engine per combustion cycle while shifting the transmission between different gear ratios. Under select conditions, the number of strokes performed by the engine per combustion cycle may be reduced while shifting the transmission from a higher gear ratio to a lower gear ratio. Under other conditions, the number of strokes performed by the engine per combustion cycle may be increased while shifting the transmission from a lower gear ratio to a higher gear ratio.

A multi-mode internal combustion engine is described. As one example, the engine may be transitioned between a two stroke mode and a four stroke mode in coordination with a transmission shift by adjusting a number of strokes performed by the engine per combustion cycle while shifting the transmission between different gear ratios. Under select conditions, the number of strokes performed by the engine per combustion cycle may be reduced while shifting the transmission from a higher gear ratio to a lower gear ratio. Under other conditions, the number of strokes performed by the engine per combustion cycle may be increased while shifting the transmission from a lower gear ratio to a higher gear ratio.

Embodiments for an engine exhaust are provided. In one example, a method comprises categorizing each respective concentration of a plurality of exhaust gas constituents measured by a gas analyzer into one of oxidants or reductants, the gas analyzer receiving exhaust gas flow from an engine. The method also includes determining an exhaust air-fuel ratio based on the categorized concentrations and validating output from an exhaust gas sensor receiving exhaust gas flow from the engine based on the determined exhaust air-fuel ratio.

A method and a system for improving operation of an automatically started engine are described. In one example, engine speed is adjusted to a sole run-up speed and, held at the desired engine run-up speed for a desired period, before being ramped to an idle speed.

An approach is described that coordinates transmission shifting with changing between two-stroke and four-stroke combustion to improve shift and drive performance. In one example, responsive to a driver tip-in, the system may transition the engine to a two-stroke combustion mode from the four-stroke mode and increase a transmission gear ratio in order to avoid transmission shifts during the subsequent acceleration.

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 a time delay and line length of each sample of a set of exhaust gas sensor responses collected during a commanded change in air-fuel ratio. In this way, the exhaust gas sensor may be monitored utilizing robust parameters in a non-intrusive manner.

A method for adjusting boost provided via a turbocharger or supercharger is described. In one example, boost is increased in response to a change in road conditions before a driver reacts to the change in road conditions by applying an accelerator pedal. The boost is increased to reduce compressor lag, thereby increasing the responsiveness of the engine and vehicle.