A method of compensating for fuel injection deviations of injectors includes: in a case of a low flow rate operating range, learning cylinder-specific lambda deviations regarding cylinder-specific engine roughness deviations using a characteristic map defining a relationship between engine roughness deviations and lambda deviations; calculating cylinder-specific amounts of injection compensation necessary to remove the cylinder-specific lambda deviations; and compensating for amounts of injection of injectors a by adding the cylinder-specific amounts of injection compensation to cylinder-specific target amounts of injection.

A method of controlling an air-fuel ratio in a pre-ignition (PI) situation, may include: monitoring, by a PI detector, whether PI occurs in a cylinder of a plurality of cylinders of an engine; and when the PI occurs in the cylinder of the plurality cylinders, controlling, by a controller, an air-fuel ratio of the cylinder in which the PI occurs to be smaller than a theoretical air-fuel ratio, and controlling an air-fuel ratio of a remaining cylinder of the plurality of cylinders in which PI does not occur to be larger than the theoretical air-fuel ratio.

An engine system including a fuel system control arrangement includes an internal combustion engine including an exhaust line, one or more cylinders, and one or more fuel injectors corresponding to the one or more cylinders, means for determining fresh air mass flow into an intake to the engine, a nitrogen oxide (NOx) sensor in the exhaust line, and a controller configured to determine oxygen (O2) in exhaust gas based on a signal from the NOx sensor and to calculate a current fuel injection quantity based on the O2 in the exhaust gas and determined fresh air mass flow into the intake, to compare the current fuel injection quantity to a theoretical fuel injection quantity under current operating conditions, and to adjust an amount of fuel injection from the one or more fuel injectors when the current fuel injection quantity differs from the theoretical fuel injection quantity to make the current fuel injection quantity closer to the theoretical fuel injection quantity.

A machine includes an engine, a selective catalytic reduction (SCR) element fixedly connected to an output of the engine, and a controller. The controller is communicatively coupled to the engine and a sensor at an output of the SCR element. The controller is configured to calculate an estimated amount of emissions at a location of the SCR element, calculate an estimated amount of emissions from an output of the SCR element, measure, using the sensor, an actual amount of emissions from the output of the SCR element, and perform a comparison of the estimated amount of emissions and the actual amount of emissions. The controller is further configured to adjust, based on the comparison, the estimated amount of emissions at the location of the SCR element, and control operation of the engine based on the adjusted amount of emissions.

An evaporative emissions (EVAP) system for an engine of a vehicle includes an ion sensing system configured to measure a fuel/air ratio (FAR) within cylinders of the engine and a controller configured to, during an engine cold start period, perform open-loop lambda control of the engine including obtaining, from the ion sensing system, the measured FAR within the cylinders of the engine, comparing the measured FAR within the cylinders of the engine to a target FAR within cylinders of the engine, and based on the comparing, adjusting operation of at least one of the EVAP system and fuel injectors of the engine to maintain a stoichiometric operation of the engine, wherein the use of the ion sensing system for open-loop lambda control of the engine eliminates the need for a hydrocarbon (HC) sensor in the EVAP system.

An internal combustion engine includes an engine block including a cylinder a piston positioned within the cylinder and configured to reciprocate in the cylinder, an electronic throttle control system comprising a motor and a throttle plate, a fuel system for supplying a controlled amount of fuel to the cylinder including a fuel injector, and an engine control unit coupled to the fuel system and the electronic throttle control system. The engine control unit is configured to determine engine speed data comprising a current engine speed, a previous engine speed, and a desired engine speed and control a fuel injection duration based on the engine speed data.

A system and method of controlling a cylinder deactivation mechanism can comprise executing a valve lift event configured to lift a valve via a rocker arm. The rocker arm can be configured with a controllable latch in a latched condition, wherein the controllable latch is configured with an edge that is clamped in a recess in the rocker arm during the valve lift event, a clamp force supplied in part by pressure from the valve lift event. A deactivation signal can be sent to select the unlatched condition to collapse the controllable latch from the recess while the controllable latch is configured in the valve lift event with the edge clamped in the recess. A subsequent valve lift event can have actuation deactivated by collapsing the controllable latch from the recess once the valve lift event is complete and the clamp force is removed.

According to the invention, a method for air path control of a combustion engine is provided, comprising an EGR valve and a VGT turbine. The method comprises providing a cost function of a measured delta pressure between engine intake and exhaust manifold; determining a gradient of the cost function as a function of a delta pressure set point, determining a gradient of a constraint function for estimated NOx emission level, turbine rate; and oxygen level as a function of delta pressure; real time controlling the NOx emission level and delta pressure to respective desired NOx and delta pressure set points by adjusting the EGR valve and/or the VGT turbine, wherein the delta pressure set point is adjusted according to an integration of a selected gradient direction of the cost function selected from the determined one or more of the gradients, wherein the determined gradients are prioritized in the order of turbine rate, oxygen level and NOx emission level; and wherein NOx emission level and or a turbine rate and or oxygen levels are constrained; and wherein the adjusted delta pressure set point is perturbed in an extremum seeking operation on the cost function.

A method determines a sensor error of a sensor in an exhaust gas system of a motor vehicle. One step of the method involves determining at least one actual sensor signal of the sensor. Another step of the method involves determining at least one target sensor signal of the sensor by means of a model. A further step of the method involves determining the sensor error of the sensor according to a deviation between the actual sensor signal of the sensor and the target sensor signal of the sensor.

Methods and systems are provided for restarting an engine following an engine idle-stop. In one example, a method may include, prior to an engine restart following an idle-stop, adjusting a spark ignition timing based on an estimation of a fuel-air equivalence ratio (phi) and an estimation of a cylinder turbulence. Optimal spark ignition timing based on estimated phi and cylinder turbulence during engine restart may result in stabilized combustion and a torque output sufficient to at least partially relieve demand on the starting device.