Methods and systems are provided for calculating a fuel aging of fuel in a fuel tank. In one example, a method may include alerting a vehicle operator and/or adjusting engine operating parameters in response to a fuel aging being greater than a threshold aging.

Systems and methods are provided for determining a temperature of a thermal system that includes fluid conduits. A sensor monitors a current state of the temperature. A controller receives a signal from the sensor that is representative of the current state; determines a flow in the fluid conduits; determines a noise covariance of the thermal system; processes a thermal model of the thermal system; predicts a next-step state of the parameter at a time after the current state; and corrects the next-step state based, at least in-part, on the noise covariance resulting in a corrected next-step state.

A boosted engine is provided, which includes an engine body formed with a combustion chamber, a spark plug, a fuel injection valve, a booster, a boost controller, and a control unit including an operating range determining module and a compression end temperature estimating module. In a high load range, the fuel injection valve and the spark plug are controlled so that a mixture gas inside the combustion chamber starts combustion through flame propagation by ignition of the spark plug, and unburned mixture gas then combusts by compression ignition, and the boost controller is controlled to bring the booster into a boosting state. When a gas temperature inside the combustion chamber exceeds a given temperature at CTDC, the fuel injection valve is controlled so that a fuel injection end timing occurs on a compression stroke, and the spark plug is controlled so that the mixture gas is ignited after CTDC.

An internal combustion engine control device (1) includes an injector-temperature calculation unit (21a), an engine-temperature calculation unit (21b), an operating-state control unit (21c), and an integration-time calculation unit (21d). The engine-temperature calculation unit (21b) calculates an engine temperature by using an injector temperature and a fuel-injection integration time.

Systems and methods are provided for determining a temperature of a thermal system that includes fluid conduits. A sensor monitors a current state of the temperature. A controller receives a signal from the sensor that is representative of the current state; determines a flow in the fluid conduits; determines a noise covariance of the thermal system; processes a thermal model of the thermal system; predicts a next-step state of the parameter at a time after the current state; and corrects the next-step state based, at least in-part, on the noise covariance resulting in a corrected next-step state.

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.

An internal combustion engine control device (1) includes an injector-temperature calculation unit (21a), an engine-temperature calculation unit (21b), an operating-state control unit (21c), a cold/warmed-up state determination unit (21d), an ambient-temperature calculation unit (21e), and a correction unit (21f). The correction unit (21f) corrects an engine temperature calculated based on an injector temperature, when it is determined that an engine is in a cold state and a difference between the injector temperature and an ambient temperature is equal to or larger than a first predetermined value.

A premixed compression ignition engine system includes an engine, a fuel injector, a water injector, and a controller. The controller conducts: a compression-stroke mid-period injection that causes a fuel injector to inject fuel to form a fuel-air mixture in a surrounding space of a combustion chamber; a compression top-dead-center injection that causes the fuel injector to inject fuel to form a fuel-air mixture in the central space of the combustion chamber after the compression-stroke mid-period injection; and a water injection that causes a water injector to inject water to the surrounding space of the combustion chamber at a timing from commencement of the compression-stroke mid-period injection to commencement of the compression top-dead-center injection.

A supercharging device for an engine is provided, which includes a supercharger provided to an intake passage of the engine, an actuator configured to drive the supercharger, and a controller including a processor configured to control the actuator to drive the supercharger when an operating state of the engine is in a given supercharging range, and to stop the supercharger when the operating state is in a non-supercharging range. The controller estimates an amount of condensate accumulated in an oil pan, and the controller causes the actuator to forcibly drive the supercharger when the estimated amount of condensate is more than a preset amount, even if the operating state is in the non-supercharging range.

The disclosure provides a combustion abnormality detecting device, a combustion abnormality detecting method, and a non-transitory computer-readable storage medium, a misfire detection accuracy is increased by increasing a piezoelectric detection accuracy. A charge amplifier (210) outputting a voltage signal corresponding to a charge generated by a piezoelectric element (35) in response to a received pressure, a drift component extracting part (230) extracting a drift component of the piezoelectric element (35), a drift correcting part (250) generating a correction signal for removing the drift component based on the extracted drift component and feeding back the correction signal to an input side of the charge amplifier (210), and a misfire detecting part (400) performing misfire detection based on the correction signal are included.