Abstract: A system and method for transitioning a firing fraction of a variable displacement internal combustion engine when generating a desired torque output. During and following the transition to the second firing fraction, a combustion recipe is ascertained and used operating the cylinders of the variable displacement internal combustion engine to generate the desired torque output. The recipe is preferably optimized for the engine operating at the second firing fraction, at least relative to the previous charge of the previous combustion recipe used with the first firing fraction.

Abstract: A method of operating an engine is provided. An exhaust valve actuation fault is detected for a first exhaust valve associated with a first cylinder during a first working cycle. In response to the detection of the exhaust valve actuation fault, fueling to at least the first cylinder is cut off. Actuation of the first exhaust valve is attempted in second working cycles that follow the first working cycle, wherein the second working cycles are not fueled. Whether or not the first exhaust valve actuated properly during the second working cycles is determined. Operation of the first cylinder is resumed when it is determined that the first exhaust valve actuated properly. Operation of the first cylinder is not resumed when it is determined that the first exhaust valve did not actuate properly.

Abstract: A system and method for the use of machine learning for detecting faults for cylinder intake and/or exhaust valves that do not properly open or close as commanded and for generating a flag for such faults.

Abstract: A system and method for controlling an internal combustion engine involving (1) cylinder trapping strategies where one of several pneumatic spring types are dynamically selected for cylinders based at least partially on a predicted number of upcoming skips for each of the cylinders respectively and/or (2) staggering various valvetrain dependent operational engine strategies as operating conditions permit as the internal combustion engine warms up following a cold start.

Abstract: Controllers and methods for managing transitions into and/or out of a cylinder cut off mode are described. In some embodiments, a skip fire based transition into a cylinder cut off mode is used in which the fraction of working cycles that are fired is gradually reduced to a threshold firing fraction. Once the threshold firing fraction has been reached, all of the working chambers are deactivated.

Abstract: A variety of methods and arrangements for controlling the exhaust gas temperature of a lean burn, skip fire controlled internal combustion engine are described. In one aspect, an engine controller includes an aftertreatment system monitor and a firing timing determination unit. The aftertreatment monitor obtains data relating to a temperature of one or more aftertreatment elements, such as a catalytic converter. Based at least partly on this data, the firing timing determination unit generates a firing sequence for operating the engine in a skip fire manner such that the temperature of the aftertreatment element is controlled within its effective operating range.

Abstract: Using machine learning for cylinder misfire detection in a dynamic firing level modulation controlled internal combustion engine is described. In a classification embodiment, cylinder misfires are differentiated from intentional skips based on a measured exhaust manifold pressure. In a regressive model embodiment, the measured exhaust manifold pressure is compared to a predicted exhaust manifold pressure generated by neural network in response to one or more inputs indicative of the operation of the vehicle. Based on the comparison, a prediction is made if a misfire has occurred or not. In yet other alternative embodiment, angular crank acceleration is used as well for misfire detection.

Abstract: A system and method for transitioning a firing fraction of a variable displacement internal combustion engine when generating a desired torque output. During and following the transition to the second firing fraction, a combustion recipe is ascertained and used operating the cylinders of the variable displacement internal combustion engine to generate the desired torque output. The recipe is preferably optimized for the engine operating at the second firing fraction, at least relative to the previous charge of the previous combustion recipe used with the first firing fraction.

Abstract: System and methods are described for optimizing exhaust flow rate and temperature during specified operational periods warm-up and keep-warm conditions, by minimizing or maximizing heat flux during those specified operational periods.

Abstract: A skip fire engine controller and method of control is described wherein during transitions from a first firing density to a second firing density, a firing density and a pumping density are separately set so as to balance the conflicting demands of (a) torque control, (b) Noise, Vibration and Harshness (NVH), (c) air flow through the engine and (d) air-fuel ratio.

Abstract: A system and method for controlling an internal combustion engine involving (1) cylinder trapping strategies where one of several pneumatic spring types are dynamically selected for cylinders based at least partially on a predicted number of upcoming skips for each of the cylinders respectively and/or (2) staggering various valvetrain dependent operational engine strategies as operating conditions permit as the internal combustion engine warms up following a cold start.

Abstract: Using machine learning for cylinder misfire detection in a dynamic firing level modulation controlled internal combustion engine is described. In a classification embodiment, cylinder misfires are differentiated from intentional skips based on a measured exhaust manifold pressure. In a regressive model embodiment, the measured exhaust manifold pressure is compared to a predicted exhaust manifold pressure generated by neural network in response to one or more inputs indicative of the operation of the vehicle. Based on the comparison, a prediction is made if a misfire has occurred or not. In yet other alternative embodiment, angular crank acceleration is used as well for misfire detection.

Abstract: System and methods are described for optimizing exhaust flow rate and temperature during specified operational periods warm-up and keep-warm conditions, by minimizing or maximizing heat flux during those specified operational periods.

Abstract: A diagnostic system and method that (a) that uses models indicative of both successful firing and skips to determine if cylinders of a skip fire controlled internal combustion engine have successfully fired or successfully skipped and (b) uses filtered exhaust gas pressure readings for detecting faults associated with EGR systems and/or turbocharger systems.

Abstract: A diagnostic system and method that (a) that uses models indicative of both successful firing and skips to determine if cylinders of a skip fire controlled internal combustion engine have successfully fired or successfully skipped and (b) uses filtered exhaust gas pressure readings for detecting faults associated with EGR systems and/or turbocharger systems.

Abstract: A variety of methods and arrangements for controlling the exhaust gas temperature of a lean burn, skip fire controlled internal combustion engine are described. In one aspect, an engine controller includes an aftertreatment system monitor and a firing timing determination unit. The aftertreatment monitor obtains data relating to a temperature of one or more aftertreatment elements, such as a catalytic converter. Based at least partly on this data, the firing timing determination unit generates a firing sequence for operating the engine in a skip fire manner such that the temperature of the aftertreatment element is controlled within its effective operating range.

Abstract: A system and method for transitioning a firing fraction of a variable displacement internal combustion engine when generating a desired torque output. During and following the transition to the second firing fraction, a charge of a combustion recipe is ascertained and used operating the cylinders of the variable displacement internal combustion engine to generate the desired torque output. The charge is preferably optimized for the engine operating at the second firing fraction, at least relative to the previous charge of the previous combustion recipe used with the first firing fraction.

Abstract: Using machine learning for cylinder misfire detection in a dynamic firing level modulation controlled internal combustion engine is described. In a classification embodiment, cylinder misfires are differentiated from intentional skips based on a measured exhaust manifold pressure. In a regressive model embodiment, the measured exhaust manifold pressure is compared to a predicted exhaust manifold pressure generated by neural network in response to one or more inputs indicative of the operation of the vehicle. Based on the comparison, a prediction is made if a misfire has occurred or not. In yet other alternative embodiment, angular crank acceleration is used as well for misfire detection.

Abstract: A diagnostic system and method that (a) that uses models indicative of both successful firing and skips to determine if cylinders of a skip fire controlled internal combustion engine have successfully fired or successfully skipped and (b) uses filtered exhaust gas pressure readings for detecting faults associated with EGR systems and/or turbocharger systems.

Abstract: A variety of methods and arrangements for controlling the exhaust gas temperature of a lean burn, skip fire controlled internal combustion engine are described. In one aspect, an engine controller includes an aftertreatment system monitor and a firing timing determination unit. The aftertreatment monitor obtains data relating to a temperature of one or more aftertreatment elements, such as a catalytic converter. Based at least partly on this data, the firing timing determination unit generates a firing sequence for operating the engine in a skip fire manner such that the temperature of the aftertreatment element is controlled within its effective operating range.