Abstract: A control technique for an engine having a two-step variable valve lift system includes a controller receiving a pressure in an intake manifold of the engine from a manifold absolute pressure (MAP) sensor and a position of an EGR valve of the engine from an exhaust gas recirculation (EGR) sensor. In response to the controller detecting an upcoming HL-to-LL valve state transition, a set of airflow actuators of the engine is controlled, based on the intake manifold pressure and the EGR valve position, to generate a first torque reserve. In response to generating the first torque reserve, the controller then commands the HL-to-LL transition and depletion of the first torque reserve during the HL-to-LL transition to mitigate torque disturbance associated with this transition.

Abstract: A boost purge ejector tee arrangement is integrated into a turbocompressor associated with an engine and includes first and second passages, an inlet port and a nozzle. The first passage is formed into a housing of the turbocompressor and includes an outlet in communication with a turbocompressor inlet. The second passage is formed into the housing and includes a boost air inlet in communication with an internal outlet area of the turbocompressor and intersecting the first passage. The inlet port is associated with the housing and intersects the first passage. The nozzle is positioned in the first passage such that an outlet of the nozzle is proximate the intersection of the inlet port and first passage. During a boost mode of operation, the second passage is adapted to receive boost air flow, which flows through the nozzle thereby creating a vacuum and drawing purge through the inlet port.

Abstract: An internal combustion engine is configured to operate in a homogeneous-charge compression-ignition combustion mode and a spark-ignition combustion mode employing late intake valve closing. A method for operating the internal combustion engine includes determining an amount of residual gas re-inducted into a combustion chamber from a previous engine cycle and determining an amount of fresh air trapped in the combustion chamber for the present engine cycle based upon the amount of residual gas re-inducted into the combustion chamber from the previous engine cycle. Engine fueling to the cylinder for the present engine cycle is controlled based upon the amount of fresh air trapped in the combustion chamber for the present engine cycle.

Abstract: A control technique for an engine having a two-step variable valve lift system includes a controller receiving a pressure in an intake manifold of the engine from a manifold absolute pressure (MAP) sensor and a position of an EGR valve of the engine from an exhaust gas recirculation (EGR) sensor. In response to the controller detecting an upcoming HL-to-LL valve state transition, a set of airflow actuators of the engine is controlled, based on the intake manifold pressure and the EGR valve position, to generate a first torque reserve. In response to generating the first torque reserve, the controller then commands the HL-to-LL transition and depletion of the first torque reserve during the HL-to-LL transition to mitigate torque disturbance associated with this transition.

Abstract: An engine bank-to-bank airflow balancing technique includes calculating current and offset volumetric efficiencies of the engine and calculating a slope representing (i) a difference between the offset and current volumetric efficiencies and (ii) a difference between offset and current intake camshaft positions. Based on the respective exhaust gas oxygen concentrations, the technique involves calculating a volumetric efficiency correction corresponding to each cylinder bank and based on the slope and the volumetric efficiency corrections, calculating target intake camshaft position shifts. The technique further involves controlling offsets of the intake camshafts based on the target intake camshaft position shifts.

Abstract: Techniques for learning endstop position(s) of an actuator for a wastegate valve include detecting a learn condition and, in response to detecting the learn condition, performing a learn procedure for the actuator endstop position(s). The learn procedure includes commanding the actuator to a desired position past the endstop position corresponding to a fully-closed wastegate valve while rate-limiting a velocity of the actuator. When the difference reaches its maximum allowed value and the velocity falls below a fraction of its rate limit, the endstop position is learned. When the wastegate valve is requested open, the actuator is then controlled using the learned endstop position. Reference stiffness for a fully-closed wastegate valve could be obtained, and subsequent stiffness checks could then be periodically performed and, if less than the reference stiffness, a duty cycle of the actuator could be increased during open-loop control.

Abstract: An engine bank-to-bank airflow balancing technique includes calculating current and offset volumetric efficiencies of the engine and calculating a slope representing (i) a difference between the offset and current volumetric efficiencies and (ii) a difference between offset and current intake camshaft positions. Based on the respective exhaust gas oxygen concentrations, the technique involves calculating a volumetric efficiency correction corresponding to each cylinder bank and based on the slope and the volumetric efficiency corrections, calculating target intake camshaft position shifts. The technique further involves controlling offsets of the intake camshafts based on the target intake camshaft position shifts.

Abstract: A technique is provided for compensating an untrimmed oxygen (O2) sensor utilized in operation of an exhaust gas recalculation (EGR) system associated with an engine. The technique includes, in one implementation, receiving a measurement from the O2 sensor at a known pressure, where the O2 sensor is positioned on an intake side of an engine system. Humidity compensation and pressure compensation are then determined for the O2 sensor measurement, where the pressure compensation is based in part on the humidity compensation. The EGR system is controlled using the untrimmed O2 sensor measurement that has been compensated for pressure and humidity.

Abstract: A boost purge ejector tee arrangement is integrated into a turbocompressor associated with an engine and includes first and second passages, an inlet port and a nozzle. The first passage is formed into a housing of the turbocompressor and includes an outlet in communication with a turbocompressor inlet. The second passage is formed into the housing and includes a boost air inlet in communication with an internal outlet area of the turbocompressor and intersecting the first passage. The inlet port is associated with the housing and intersects the first passage. The nozzle is positioned in the first passage such that an outlet of the nozzle is proximate the intersection of the inlet port and first passage. During a boost mode of operation, the second passage is adapted to receive boost air flow, which flows through the nozzle thereby creating a vacuum and drawing purge through the inlet port.

Abstract: An internal combustion engine is configured to operate in a homogeneous-charge compression-ignition combustion mode and a spark-ignition combustion mode employing late intake valve closing. A method for operating the internal combustion engine includes determining an amount of residual gas re-inducted into a combustion chamber from a previous engine cycle and determining an amount of fresh air trapped in the combustion chamber for the present engine cycle based upon the amount of residual gas re-inducted into the combustion chamber from the previous engine cycle. Engine fueling to the cylinder for the present engine cycle is controlled based upon the amount of fresh air trapped in the combustion chamber for the present engine cycle.

Abstract: An engine system and method for variable valve lift (VVL) diagnostic techniques are provided. In one exemplary implementation, the techniques include receiving, at a controller, a camshaft position signal indicative of detected edges of teeth of a camshaft toothed member that is coupled to a camshaft of an engine. The camshaft is configured to actuate a VVL system, which is configured to control a lift of a valve of the engine. The techniques also include calculating, at the controller, a camshaft speed signal indicative of a rotational speed of the camshaft based on the camshaft position signal. A valve stuck index (VSI) value is then calculated, at the controller, based on the camshaft speed signal. The techniques also include determining, at the controller, whether the valve is stuck based on a comparison of the VSI value to a predetermined threshold.

Abstract: A system for a vehicle includes a mode control module and a valve control module. The mode control module selectively sets an ignition mode for an engine to one of a spark ignition (SI) mode and a homogenous charge compression ignition (HCCI) mode. In response to the ignition mode transitioning from the SI mode to the HCCI mode during a first engine cycle, the valve control module operates an exhaust valve in a high lift mode during a second engine cycle, operates an intake valve in a low lift mode during the second engine cycle, and operates the exhaust and intake valves in the low lift mode during a third engine cycle. The first engine cycle is before the second engine cycle, and the second engine cycle is before the third engine cycle.

Abstract: An engine control system for a vehicle includes an oxygen mass flow rate module, an oxygen per cylinder module, and a fuel control module. The oxygen mass flow rate module generates a mass flow rate of oxygen flowing into an engine based on a mass air flow rate (MAF) into the engine and a percentage of oxygen by volume measured using an intake oxygen (IO) sensor in an intake system. The oxygen per cylinder module generates a mass of oxygen for a combustion event of a cylinder of the engine based on the mass flow rate of oxygen flowing into the engine. The fuel control module controls fueling to the cylinder for the combustion event based on the mass of oxygen.

Abstract: A system for a vehicle includes a mode control module and a valve control module. The mode control module selectively sets an ignition mode for an engine to one of a spark ignition (SI) mode and a homogenous charge compression ignition (HCCI) mode. In response to the ignition mode transitioning from the SI mode to the HCCI mode during a first engine cycle, the valve control module operates an exhaust valve in a high lift mode during a second engine cycle, operates an intake valve in a low lift mode during the second engine cycle, and operates the exhaust and intake valves in the low lift mode during a third engine cycle. The first engine cycle is before the second engine cycle, and the second engine cycle is before the third engine cycle.