Abstract: Methods and systems are provided for adjusting operation of a split exhaust engine system based on a total flow of gases through a scavenge exhaust gas recirculation system of the split exhaust engine system. In one example, a method may include setting a cam timing correction based on a difference between a first value and a second value of a flow through an exhaust gas recirculation (EGR) passage, the first value determined based on a first parameter set including a cylinder valve overlap area and the second value determined based on a second parameter set not including the cylinder valve overlap area, and operating at least one of an intake cam and an exhaust cam at a corrected timing using the cam timing correction. In this way, the flow through the EGR passage may be adjusted even without active control of a valve coupled in the EGR passage.

Abstract: Methods and systems are provided for adjusting operation of a split exhaust engine system based on a total flow of gases through a scavenge exhaust gas recirculation system of the split exhaust engine system. In one example, a method may include setting a cam timing correction based on a difference between a first value and a second value of a flow through an exhaust gas recirculation (EGR) passage, the first value determined based on a first parameter set including a cylinder valve overlap area and the second value determined based on a second parameter set not including the cylinder valve overlap area, and operating at least one of an intake cam and an exhaust cam at a corrected timing using the cam timing correction. In this way, the flow through the EGR passage may be adjusted even without active control of a valve coupled in the EGR passage.

Abstract: A computing device in a vehicle can emit a sequence of light pulses having a first speed, then receive a signal from another vehicle. Following this, the computing device can emit a message as a sequence of light pulses having a second speed based on the signal received from the vehicle, wherein the first speed is different from the second speed.

Abstract: Systems and methods for operating an engine that includes a compression ratio linkage for adjusting engine compression ratio are described. The systems and methods provide different ways of changing a compression ratio of an engine based on forecast or anticipated engine operating conditions. In one example, the forecast or anticipated engine operating conditions may include a forecast or anticipated transmission gear shift.

Abstract: Systems and methods for operating an engine that includes a compression ratio linkage for adjusting engine compression ratio are described. The systems and methods provide different ways of changing a compression ratio of an engine based on forecast or anticipated engine operating conditions. In one example, the forecast or anticipated engine operating conditions may include a forecast or anticipated transmission gear shift.

Abstract: Embodiments for diagnosing a humidity sensor are provided. One example method comprises adjusting an engine operating parameter based on humidity of a first gas flow measured by a humidity sensor, and indicating degradation of the humidity sensor if a humidity of a second gas flow measured by the humidity sensor is different than an expected humidity. In this way, degradation of the humidity sensor may be indicated if the humidity of the second gas flow measured by the humidity sensor is different than expected.

Abstract: A first vehicle includes: steering, brakes, memory, sensors, and processor(s) configured to: determine, with the sensors: the first vehicle's acceleration, a second vehicle's acceleration; compute a theoretical collision velocity (TCV) between the first vehicle and the second vehicle based on the accelerations; apply a function or generate a command based on the TCV and a selected coefficient of kinetic friction (COF).

Abstract: A diagnostic method for a capacitive humidity sensor comprising a heater, and a capacitance-sensing element that individually identifies heater, temperature-sensing element, or capacitance-sensing element degradation. By this method, individual elements of the sensor may be replaced or compensated for to allow for further operation.

Abstract: A computing device in a vehicle can emit a sequence of light pulses having a first speed, then receive a signal from another vehicle. Following this, the computing device can emit a message as a sequence of light pulses having a second speed based on the signal received from the vehicle, wherein the first speed is different from the second speed.

Abstract: Infrared light is detected in a vehicle computer via an infrared sensor from a source outside the host vehicle. The computer can further determine that the infrared light was generated from a source in a second vehicle, detect the second vehicle based at least partly on the detected infrared light and possibly also partly on input from a host vehicle collision detection sensor.

Abstract: Methods and systems are provided for diagnosing an intake oxygen sensor. In one example, a method may include indicating degradation of an intake oxygen sensor based on a first time constant of an output of the intake oxygen sensor and a second time constant of an output of a throttle inlet pressure sensor. The method may further include adjusting EGR flow based on the output of the intake oxygen sensor and the output of the throttle inlet pressure sensor when the intake oxygen sensor is not degraded.

Abstract: Infrared light is detected in a vehicle computer via an infrared sensor from a source outside the host vehicle. The computer can further determine that the infrared light was generated from a source in a second vehicle, detect the second vehicle based at least partly on the detected infrared light and possibly also partly on input from a host vehicle collision detection sensor.

Abstract: Methods and systems are provided for accurately learning the zero point of an intake gas oxygen sensor during selected engine no-fueling conditions. The learned zero point is used to infer EGR flow and accordingly adjust EGR valve control. In addition, EGR valve leakage is diagnosed based on the zero point learned during a DFSO adaptation relative to a zero point learned during an idle adaptation.

Abstract: A first vehicle includes: steering, brakes, memory, sensors, and processor(s) configured to: determine, with the sensors: the first vehicle's acceleration, a second vehicle's acceleration; compute a theoretical collision velocity (TCV) between the first vehicle and the second vehicle based on the accelerations; apply a function or generate a command based on the TCV and a selected coefficient of kinetic friction (COF).

Abstract: Methods and systems are provided for determining changes in a flow area of an exhaust gas recirculation (EGR) valve for EGR flow estimates due to soot accumulation on the EGR valve. In one example, a method includes indicating soot accumulation on the EGR valve based on a difference in EGR flow estimated with an intake oxygen sensor and with a pressure sensor coupled across the EGR valve. The determination of the difference of the EGR flow estimates may occur when the engine is not boosted.

Abstract: Methods and systems are provided for an engine including a humidity sensor. Degradation of the humidity sensor may be determined based on a change in intake air relative humidity as compared to a change in intake air temperature or pressure, under selected conditions. An amount of exhaust gas recirculated to an engine intake is adjusted differently based on whether the humidity sensor is degraded or functional.

Abstract: Embodiments for diagnosing a humidity sensor are provided. One example method comprises, responsive to a humidity sensor test cycle, pumping air conditioning and windshield washer gas flows past a humidity sensor, and indicating humidity sensor degradation based on a response of the humidity sensor to the air conditioning and windshield washer gas flows. In this way, degradation of the humidity sensor may be indicated if the humidity sensed by the humidity sensor does not change responsive to the humidity sensor test cycle being initiated.

Abstract: Methods and systems are provided for indicating water at an oxygen sensor based on power consumption of a heating element of the oxygen sensor. In one example, water may be indicated at an oxygen sensor positioned in an intake of an engine responsive to power consumption of the heating element of the oxygen sensor increasing above a baseline level. Engine operating parameters may then be adjusted based on the water indication and the power consumption.

Abstract: Methods and systems are provided for reducing EGR estimation errors during lean engine operating conditions. During lean engine operation, EGR is disabled if the estimated exhaust air-fuel ratio becomes leaner than a lean threshold. The lean threshold is adjusted based on an upper limit of EGR errors that may be tolerated by the engine at a given engine speed and load.

Abstract: Embodiments for testing a humidity sensor are provided. One example method comprises indicating degradation of a humidity sensor based on a humidity sensor output and output from an intake gas composition sensor. In this way, output from the intake gas composition sensor may be used to determine if the humidity sensor is degraded.