Methods and systems are provided for fueling an engine of a vehicle during an exit from a deceleration fuel shut-off (DFSO) condition. In one example, a method may include fueling the engine using a compression stroke direct injection during the exit from the DFSO condition to reach a first engine torque threshold, and may further include increasing a separation between the compression stroke direct injection and a spark to gradually increase the engine torque to a second, higher engine torque threshold, and thereafter transitioning engine fueling from the compression stroke direct injection to an intake stroke direct injection. In this way, torque bumps may be reduced during DFSO exit.

Provided is a control device of a hybrid vehicle powered by an internal-combustion engine and a motor, wherein a catalyst that purifies exhaust gas is located in an exhaust passage of the internal-combustion engine, and the control device comprises: a learning unit configured to, during operation of the internal-combustion engine, learn a parameter for controlling a rotation speed of the internal-combustion engine so that a rotation speed of the internal-combustion engine during idling operation is equal to a target rotation speed; and a controller configured to stop the internal-combustion engine when a state where a correction amount of the parameter to cause the rotation speed during idling operation to be equal to the target rotation speed is equal to or greater than a predetermined value continues for equal to or greater than a predetermined time period, the correction amount being obtained by learning by the learning unit.

A method for modelling engine emissions output is provided. The method includes determining a stoichiometric engine output emission value based on a dynamic data-based model and parameters associated with at least one engine operating state, wherein the at least one engine operating state is calculated at a substantially stoichiometric air-fuel ratio, selecting a target air-fuel ratio based on the at least one engine operating state and a desired engine performance, applying a predetermined static model to determine a correction factor to the stoichiometric engine output emission value, based on the target air-fuel ratio, and applying the correction factor to the determined stoichiometric engine output emission value to yield an air-fuel-ratio-corrected emission output value.

A system for analyzing an engine of a vehicle may comprise a computer including a computer processor, a sensor connected to a portion of the vehicle and being configured to provide an engine signature to the computer, a simulator module configured to utilize the computer processor to generate simulated signature features associated with a simulated vehicle having prescribed defects, and a self-learning module configured to utilize the computer processor to learn associations between the simulated signature and prescribed defects. The computer processor may be configured to compare the engine signature with the associations of the self-learning module to produce a probability indicator that the engine has the prescribed defect at a specified intensity associated with a diagnosis of the engine.

Particulate accumulation in a particulate filter in the exhaust line of an engine is calculated by an electronic engine control unit. When the estimated accumulated particulate mass exceeds a predetermined threshold, an automatic regeneration step of the filter is activated. An actual instantaneous burned particulate mass is calculated as a function of values indicative of the state of the filter. A temporary correction factor representing an error between a theoretical value and the actual value is calculated. The temporary correction factor is stored in a second map of correction factors, based on the engine operating conditions. During an accumulation step, the estimated instantaneous particulate mass, calculated according to the first map based on the operating conditions of the engine, is multiplied by a correction factor calculated according to the second map based on the operating conditions of the engine.

A vaporized fuel treatment device includes a sealing valve disposed in a vapor passage between a fuel tank and a canister and including a valve element that moves in an axial direction with respect to a valve seat, a cut-off valve that cuts off a communication between the canister and an atmosphere, a pump that reduces an internal pressure of the canister, a vapor passage diagnostic module that decreases an internal pressure of the fuel tank by the pump via the canister so as to diagnose whether leakage occurs in the vapor passage in a state where the communication between the canister and the atmosphere is cut off and the sealing valve is opened, and a learning module that executes a learning of a valve opening start position of the sealing valve based on a change in the internal pressure of the fuel tank when changing an axial distance between the valve element and the valve seat when the internal pressure of the fuel tank is equal to or smaller than a predetermined value after a diagnosis of leakage in the vapor passage.

A control system for an internal combustion engine, which is capable of controlling fuel injection valves while causing valve-closing delay time periods, which occur with the valves actually mounted on the engine, to be reflected thereon, thereby making it possible to improve exhaust emission characteristics and fuel economy performance. The ECU of the control system performs initial value-specific control in fuel injection control and ignition timing control, such that initial value acquisition conditions are satisfied, so as to calculate the initial values of the valve-closing delay time periods when the initial value acquisition conditions are satisfied. When normal-time control is performed, the valve-opening time periods of the valves are calculated using the initial values of the valve-opening time periods, and the valves are controlled to be open over the valve-opening time periods.

A method for determining an average segment time of an encoder wheel of an internal combustion engine, the encoder wheel being connected in rotationally fixed fashion to a crankshaft of the internal combustion engine, markings being situated along the circumference of the encoder wheel, and the crankshaft of the internal combustion engine passing through specified angular ranges during segment times, segment times being acquired, associated rotational speed values being determined from the segment times, a rotational speed curve being determined from the individual determined rotational speed values, a value of the average rotational speed being determined from the rotational speed curve, and an average segment time being determined from the value of the average rotational speed.

An ECU has a fuel pressure sensor that detects fuel pressure inside of a common rail. The ECU detects the fuel pressure at a predetermined frequency and calculates a drop amount of the fuel pressure in accordance with fuel injection by fuel injectors based on the detected fuel pressure. The ECU acquires a fluctuation amount of a fuel injection amount of each of the fuel injectors based on the drop amount of the fuel pressure and learns an injection characteristic of each of the fuel injectors, the injection characteristic indicating a correlation between the fuel injection amount and the fluctuation amount of the fuel injection. In a case in which a detection timing of the fuel pressure is within a fuel injection period of a predetermined fuel injector, the ECU disallows the learning of the injection characteristic using the fuel pressure detected in the fuel injection period.

Methods and systems are provided for fueling an engine of a vehicle during an exit from a deceleration fuel shut-off (DFSO) condition. In one example, a method may include fueling the engine using a compression stroke direct injection during the exit from the DFSO condition to reach a first engine torque threshold, and may further include increasing a separation between the compression stroke direct injection and a spark to gradually increase the engine torque to a second, higher engine torque threshold, and thereafter transitioning engine fueling from the compression stroke direct injection to an intake stroke direct injection. In this way, torque bumps may be reduced during DFSO exit.