Described herein is a process for designing a virtual sensor that is able to estimate a variable of interest v as a function of a set of available variables u.sub.i. The process comprises the steps of: acquiring (1002) a design data-set D.sub.d comprising a number N of measured values v(ti) of the variable of interest v and corresponding measured values i(ti) of the available variables u.sub.i; determining a limit on the disturbances of the available variables u.sub.i and a limit on the errors of the method of measurement of the variable of interest v; selecting (1004) a Lipschitz function * with a respective Lipschitz constant , which is able to estimate the variable of interest v(t) as a function of a number n of past values of each available variable u.sub.i, by executing the following steps one or more times for different numbers n: a) determining a value for the Lipschitz constant y; b) defining (1006) a maximum limit (r(t)) and a minimum limit (r(t)) for the estimate of the variable of interest v as a function of the design data-set D.sub.d, and moreover the number n, the value for the Lipschitz constant y, the limit on the disturbances of the available variables u.sub.i, and the limit on the errors of the method of measurement of the variable of interest v, and choosing a Lipschitz function * comprised between the maximum limit (r(t)) and the minimum limit (r(t)); c) determining (1008) an estimation error *(*) for the Lipschitz function * and selecting the Lipschitz function *, associated to which is a respective Lipschitz constant y* and a respective number n*, that presents the minimum estimation error *(*(y*, n*)); and implementing (1012) the selected Lipschitz function * in an electronic circuit.

A state quantity estimating device is configured to: calculate a total enthalpy given to the air by the impeller, an adiabatic compression efficiency of the compressor, and a diffuser outlet flow speed; allocate, to an internal energy and a pressure energy, a value obtained by subtracting a kinetic energy based on the diffuser outlet flow speed from the total enthalpy, based on the adiabatic compression efficiency; and calculate a compression temperature of air flowing into the outlet surface, using an operational equation that includes, as variables, the internal energy, and an inlet temperature of air prior to being compressed by the impeller, and calculate a compression pressure of the air flowing into the outlet surface, using an operational equation that includes, as variables, the pressure energy, and an inlet pressure of the air prior to being compressed by the impeller.

A system for controlling a compressor may include an engine controller that controls a fuel injection amount corresponding to an engine load and an opening amount of a throttle by reflecting a required torque required for an air conditioner (A/C), an operation information detector for detecting operation information according to driving state of the vehicle, a compressor that generates pressure during operation of the A/C, an air conditioner relay which is turned on when the air conditioner operates and is turned off when the A/C is stopped, and a controller which determines an engine negative pressure of an intake manifold, and when the cooling water temperature is lower than the predetermined temperature and the intake manifold pressure is lower than the first threshold value, a cold-start intake manifold negative pressure insufficient event is generated to reduce the A/C duty in accordance with the entry into a negative pressure recovery mode.

A method for monitoring leakage of an exhaust gas recirculation system for an engine of a vehicle includes: determining, by a controller, whether the engine is in an idle state in which the exhaust gas recirculation system is not operated; determining, by the controller, whether small flow leakage of the exhaust gas recirculation system occurs based on a predicted pressure of gas sucked into an intake manifold connected to the engine and a measured pressure of gas sucked into the intake manifold when the engine is in the idle state; and determining, by the controller, that leakage of the exhaust gas recirculation system occurs when the measured pressure is greater than the predicted pressure.

An engine system incorporating an engine, one or more sensors, and a controller. The controller may be connected to the one or more sensors and the engine. The one or more sensors may be configured to sense one or more parameters related to operation of the engine. The controller may incorporate an air-path state estimator configured to estimate one or more air-path state parameters in the engine based on values of one or more parameters sensed by the sensors. The controller may have an on-line and an off-line portion, where the on-line portion may incorporate the air-path state estimator and the off-line portion may configure and/or calibrate a model for the air-path state estimator.

A skip fire control system for an engine of a vehicle includes a set of sensors configured to measure a set of operating parameters of the engine corresponding to a volumetric efficiency of the engine, a set of sub-systems having a set of operational states that affect transitions between different firing patterns/fractions of the engine, and a controller configured to, based on the set of operating parameters and the set of operational states of the set of sub-systems, determine a best firing pattern/fraction by taking into account losses or penalties to transition at least some of the set of operational states of the set of sub-systems to obtain a target firing pattern/fraction, and control the engine based on the target firing pattern/fraction to maximize an efficiency of the engine.

A method for diagnosing the valve timing of an internal combustion engine, a characteristic curve of an actual intake manifold pressure signal being ascertained as a function of a crankshaft signal, the characteristic curve of the actual intake manifold pressure signal being compared to a characteristic curve of a setpoint intake manifold pressure signal and a shift of the valve timing being diagnosed in the event of a specifiable deviation of the actual intake manifold pressure signal from the setpoint intake manifold pressure signal.

Systems and methods for detecting a clogged intake air filter in a turbocharged engine system are provided. In one example a method for an engine coupled to an air filter and to a fuel tank includes indicating air filter clogging responsive to a measured fuel tank pressure during boosted engine operation. In this way, clogging of the air filter may be determined using existing engine system components.

An engine system incorporating an engine, one or more sensors, and a controller. The controller may be connected to the one or more sensors and the engine. The one or more sensors may be configured to sense one or more parameters related to operation of the engine. The controller may incorporate an air-path state estimator configured to estimate one or more air-path state parameters in the engine based on values of one or more parameters sensed by the sensors. The controller may have an on-line and an off-line portion, where the on-line portion may incorporate the air-path state estimator and the off-line portion may configure and/or calibrate a model for the air-path state estimator.

An air-bypass valve control device is disposed in an engine. The engine includes an intake passage, a compressor, a throttle valve, an air-bypass passage and the air-bypass valve. The air-bypass valve control device includes an intake air amount detector, a controller. The intake air amount detector detects an intake air amount of the engine. The controller configured to temporarily bring the air-bypass valve into an opened state in the case where the intake air amount of the engine immediately before a decrease in an opening degree of the throttle valve is equal to or larger than a predetermined value when the opening degree of the throttle valve decreases at a predetermined speed or higher.