An object of the present invention is to predict change of a combustion limit due to cycle variation of temperature and an EGR ratio and perform correction every cycle to decrease an amount of combustion consumption. Therefore, in an internal combustion engine control device that controls an internal combustion engine including a cylinder and an exhaust pipe, the internal combustion engine control device includes a control unit configured to perform EGR control of controlling an exhaust gas in the exhaust pipe to return to an inner cylinder of the cylinder, obtain temperature of the gas in the internal cylinder and an EGR ratio in a state where both an intake valve and an exhaust valve are closed in an combustion cycle, and correct a combustion parameter in a same combustion cycle as the combustion cycle on the basis of the obtained gas temperature and the obtained EGR ratio.

A system includes a control system configured to monitor operating conditions in at least a first cylinder of a reciprocating engine and to control the reciprocating engine, wherein the control system includes a first sensor configured to monitor a first type of operating condition of the first cylinder, and a controller communicatively coupled with the first sensor. The controller is configured to receive a first signal indicative of a first measurement of the first type of operating condition from the first sensor; analyze the first signal to detect a misfire condition in the first cylinder; derive an amount of residual gas in the first cylinder if the misfire condition is detected; and adjust control of the reciprocating engine based on the amount of residual gas.

A system includes a control system configured to monitor operating conditions in at least a first cylinder of a reciprocating engine and to control the reciprocating engine, wherein the control system includes a first sensor configured to monitor a first type of operating condition of the first cylinder, and a controller communicatively coupled with the first sensor. The controller is configured to receive a first signal indicative of a first measurement of the first type of operating condition from the first sensor; analyze the first signal to detect a misfire condition in the first cylinder; derive an amount of residual gas in the first cylinder if the misfire condition is detected; and adjust control of the reciprocating engine based on the amount of residual gas.

Disclosed are model-based combustion timing systems and control logic for engine assemblies, methods for making/operating such engine assemblies, and motor vehicles with spark-ignited engine assemblies implementing model-based combustion timing. A method for controlling torque output of an engine assembly includes receiving a requested torque demand for the engine, and determining a current fuel command and valve timing for the engine's power cylinder(s). A first math model is used to determine a desired CA50 based on the requested torque demand, a power cylinder indicated mean effective pressure (IMEP), an expander cylinder IMEP, and the current fuel command/valve timing. A second math model is used to determine a maximum brake torque (MBT) CA50 based on power cylinder and expander cylinder IMEPs, and current fuel command/valve timing. An engine control unit determines a final spark timing based on a correlation between the desired CA50 and MBT CA50, modified by a spark timing gain.

In starting of an internal combustion engine, among a plurality of combustions of the internal combustion engine when it is assumed that an ignition timing is set to a predetermined reference ignition timing, a preceding ignition timing, which is the ignition timing for a preceding combustion through which a peak of a rotation speed of the internal combustion engine is likely to enter a predetermined resonance rotation speed range where resonance of the conveyance dependent on vibration of the internal combustion engine is induced, is set further on a delay angle side than the reference ignition timing, and a later ignition timing, which is the ignition timing for a later combustion after the preceding combustion, is set further on an advance angle side than the set preceding ignition timing so that the peak of the rotation speed of the internal combustion engine exceeds the resonance rotation speed range.

In starting of an internal combustion engine, among a plurality of combustions of the internal combustion engine when it is assumed that an ignition timing is set to a predetermined reference ignition timing, a preceding ignition timing, which is the ignition timing for a preceding combustion through which a peak of a rotation speed of the internal combustion engine is likely to enter a predetermined resonance rotation speed range where resonance of the conveyance dependent on vibration of the internal combustion engine is induced, is set further on a delay angle side than the reference ignition timing, and a later ignition timing, which is the ignition timing for a later combustion after the preceding combustion, is set further on an advance angle side than the set preceding ignition timing so that the peak of the rotation speed of the internal combustion engine exceeds the resonance rotation speed range.

A handheld work apparatus has a combustion engine and an ignition device for controlling a spark plug. The ignition device includes an electronic control device having a short circuit button for switching off the combustion engine. A temperature sensor is for capturing an operating temperature. The short circuit button and the temperature sensor are connected to a common signal input of the control device via a common signal line. The temperature sensor is an ohmic resistance variable on the basis of the temperature. A measurement voltage dropped across the resistance of the temperature sensor is supplied, as an analog temperature signal, to a common analog signal input of the control device. The measurement voltage at the temperature sensor collapses in the button position of the short circuit button, as a result of which the analog temperature signal applied to the analog signal input of the control device is extinguished.

A handheld work apparatus has a combustion engine and an ignition device for controlling a spark plug. The ignition device includes an electronic control device having a short circuit button for switching off the combustion engine. A temperature sensor is for capturing an operating temperature. The short circuit button and the temperature sensor are connected to a common signal input of the control device via a common signal line. The temperature sensor is an ohmic resistance variable on the basis of the temperature. A measurement voltage dropped across the resistance of the temperature sensor is supplied, as an analog temperature signal, to a common analog signal input of the control device. The measurement voltage at the temperature sensor collapses in the button position of the short circuit button, as a result of which the analog temperature signal applied to the analog signal input of the control device is extinguished.

A method for engine drivability robustness includes: dividing, by an engine controller, an engine state into a starting condition, a stop condition, and a deceleration condition; dividing an injection mode index of a fuel injection into a suction compression injection of the starting condition, a suction split injection of the stop condition, and a suction compression split injection of the deceleration condition, respectively, depending on a low volatile fuel condition; and performing a variable indexing mode to prevent an engine off by applying a lambda control factor for a rich lambda control by an increase in fuel amount to the deceleration condition.

A method and a controller for controlling spark timing in a cold start condition for an engine in a vehicle propulsion system. The method includes determining whether the engine is in a cold start condition, and advancing spark timing before top dead center in a combustion cycle such that combustion heat is primarily received by a surface in a combustion chamber in the engine if the engine is in a cold start condition.