A fresh air and exhaust gas control method for an engine includes monitoring parameters of an engine in an operational state using a plurality of sensors and generating engine state estimates using an engine observer model. The engine observer model represents an intake manifold volume, an exhaust manifold volume, and a charge air cooler volume. The method also includes generating a turbocharger rotational speed estimate using a turbocharger model and calculating a fresh air flow correction factor. The method further includes determining a desired air throttle position and a desired EGR valve position based on setpoint commands, the monitored engine parameters, the fresh air flow correction factor, the engine state estimates, and the turbocharger rotational speed estimate. The method additionally includes adjusting the air throttle based on the desired air throttle position and adjusting the EGR valve based on the desired EGR valve position.

An active purge system may include: a canister to collect therein an evaporation gas evaporated from a fuel tank; a purge line to connect the canister to an intake pipe; a purge pump to pressurize the evaporation gas to allow the evaporation gas to move from the canister to the intake pipe; a purge valve installed on the purge line to be located between the purge pump and the intake pipe; and an engine connected to the intake pipe. In particular, the engine includes an injector installed on a cylinder head, an intake valve, and an exhaust valve.

Techniques for controlling a forced-induction engine having a low pressure exhaust gas recirculation (LPEGR) system comprise determining a desired differential pressure (dP) at an inlet of a boost device based on an engine mass air flow (MAF) and a speed of the engine, wherein the engine further comprises a dP valve disposed upstream from an EGR port and a throttle valve disposed downstream from the boost device, determining a desired EGR mass fraction based on at least the engine MAF and the engine speed, determining a maximum throttle inlet pressure (TIP) based on the engine speed, the desired EGR mass fraction, and a barometric pressure, and performing coordinated control of the dP valve and the throttle valve based on the desired dP and the maximum TIP, respectively, thereby extending EGR operability to additional engine speed/load regions and increasing engine efficiency.

An oxygen concentration-based exhaust gas recirculation (EGR) flow rate compensation control method may include a model compensation mode, which confirms engine information acquired from an engine system, calculates an intake oxygen concentration by a model intake oxygen mass ratio through a combination of an intake oxygen mass ratio model value and a model exhaust lambda value and an indirect intake oxygen mass ratio through a combination of the intake oxygen mass ratio model value and an exhaust-side measurement lambda value, respectively, and compensates the model intake oxygen mass ratio as a model intake oxygen mass ratio compensation value applying a compensation error relative to the indirect intake oxygen mass ratio by using the model intake oxygen mass ratio as a model intake oxygen mass ratio current value, by a controller.

Methods and systems are provided for controlling operation of an engine of a vehicle to supply power to a power box that in turn supplies power to loads external to the vehicle. In one example, a method comprises, responsive to a request by an operator to operate an engine to power one or more loads external to the vehicle, monitoring an engine temperature and issuing an alert requesting the operator to take mitigating action to reduce the engine temperature when the engine temperature reaches a threshold temperature, and controlling a cooling fan as a function of whether or not the mitigating action is taken. In this way, fuel economy may be improved and power supply to power external loads may be optimized.

A control system for a compression ignition engine is provided, which includes a combustion chamber, a throttle valve, an injector, an ignition, a swirl control valve, a sensor and a controller. The controller is configured to execute a first mode module, a second mode module, and a changing module to change an engine mode from a first mode to a second mode in response to a change demand. The changing module outputs signals to the throttle valve and the injector in response to the demand so that an air-fuel ratio of mixture gas becomes a stoichiometric air-fuel ratio, and outputs a signal to the swirl control valve so that an EGR gas amount decreases more than before the demand, and when the EGR gas amount is determined to be decreased to a given amount, the changing module causes the second mode module to start the second mode.

The invention concerns an internal combustion engine system (2), comprising an internal combustion engine (4) and an exhaust gas recirculation circuit (12, 14, 16, 18, 20, 22) connecting an exhaust manifold (8) of the engine to an intake manifold (6) of the engine, the circuit comprising at least one reed valve (16), an EGR valve (22), that is arranged downstream of the reed valve on the path of exhaust gas flowing from the exhaust manifold (8) to the intake manifold (6) and an EGR line (18) connecting the reed valve to the EGR valve. The system further includes a bypass line (30) for gas, connecting the EGR line (18) to an exhaust line (10) of the engine and control means (20, 40, 42) for controlling the flow of gas discharged through the bypass line.

An EGR control apparatus for the engine includes an ECU. The ECU calculates a LP-side correction coefficient Kcor_LP and a HP-side correction coefficient Kcor_HP such that they include a LP-side FB correction value Dfb_LP and a HP-side FB correction value Dfb_HP that are calculated using equations (9) and (17) such that an absolute value of an EGR amount error E_egr is reduced, and a LP-side learned value CorMAP_LP/HP-side learned value CorMAP_HP learned when a LP ratio R_LP=1/R_LP=0 holds, calculates a target LP opening _LP_dmd and a target HP opening _HP_dmd using the LP-side correction coefficient Kcor_LP and the HP-side correction coefficient Kcor_HP, and controls a LP opening _LP and a HP opening _HP such that they become equal to the target LP opening _LP_dmd and the target HP opening _HP_dmd.

An abnormality detection device for an air-fuel ratio sensor is provided. An air-fuel ratio sensor is provided in an exhaust passage. A storage device stores mapping data specifying a mapping. The mapping outputs an abnormality determination variable using first time series data and second time series data as an input. The first time series data is time series data of an excess amount variable in a first predetermined period. The excess amount variable is a variable corresponding to an excess amount of fuel actually discharged to the exhaust passage in relation to an amount of fuel reacting without excess or deficiency with oxygen contained in a fluid discharged to the exhaust passage. The second time series data is time series data of an air-fuel ratio detection variable in a second predetermined period.

An EGR device includes an EGR flow path, an EGR valve, a stepping motor, a motor driver, a return spring, a speed detector, and an opening degree estimator. The EGR flow path conveys exhaust gas from an exhaust flow path of an engine to an intake flow path. The EGR valve is disposed on the EGR flow path. The stepping motor drives the EGR valve to open to close. The motor driver supplies driving power to the stepping motor. The return spring urges the EGR valve in a valve closing direction. The speed detector detects an output shaft rotation speed of the engine. The opening degree estimator estimates an opening degree of the EGR valve. The motor driver changes a drive frequency of the stepping motor according to variations of the output shaft rotation speed detected by the speed detector and the opening degree estimated by the opening degree estimator.