A control method, a control device, an electronic device and a storage medium for engine operation are provided. The method includes: obtaining a rotational speed and a temperature of an engine at a current time and determining a reference value of the control parameter of the engine based on the rotational speed and the temperature; detecting a composite operating state of the engine at the current time and determining an offset of the control parameter corresponding to each operating state in the composite operating state; adding the reference value of the control parameter and the offset of the control parameter corresponding to each operating state in the composite operating state to obtain a final value of the control parameter; and controlling the engine at the current time according to the final value of the control parameter.

In a cooling apparatus including a high-temperature-side radiator in a high-temperature-side cooling circuit supplying a high-temperature coolant to a cylinder head, a low-temperature-side radiator in a low-temperature-side cooling circuit supplying a low-temperature coolant to an intercooler, and an electronic control unit, the high-temperature-side cooling circuit includes a first coolant passage where the high-temperature coolant flows around an exhaust port, a second coolant passage where the high-temperature coolant flows through the cylinder head without flowing around the exhaust port, and a flow rate adjustment valve adjusting a flow rate of the high-temperature coolant flowing through the first coolant passage. The electronic control unit executes a response improvement process for controlling the flow rate adjustment valve to reduce the flow rate of the high-temperature coolant flowing through the first coolant passage, and for controlling the low-temperature-side pump to increase a flow rate of the low-temperature coolant circulating through the low-temperature-side cooling circuit.

In a cooling apparatus including a high-temperature-side radiator in a high-temperature-side cooling circuit supplying a high-temperature coolant to a cylinder head, a low-temperature-side radiator in a low-temperature-side cooling circuit supplying a low-temperature coolant to an intercooler, and an electronic control unit, the high-temperature-side cooling circuit includes a first coolant passage where the high-temperature coolant flows around an exhaust port, a second coolant passage where the high-temperature coolant flows through the cylinder head without flowing around the exhaust port, and a flow rate adjustment valve adjusting a flow rate of the high-temperature coolant flowing through the first coolant passage. The electronic control unit executes a response improvement process for controlling the flow rate adjustment valve to reduce the flow rate of the high-temperature coolant flowing through the first coolant passage, and for controlling the low-temperature-side pump to increase a flow rate of the low-temperature coolant circulating through the low-temperature-side cooling circuit.

An internal combustion engine of a vehicle is equipped with a plurality of cylinders, and ignition devices provided for the cylinders respectively. The vehicle is mounted with an ECU. The ECU performs an ignition timing decision process for deciding a basic ignition timing of the ignition devices in accordance with a load of the internal combustion engine. The ECU performs a misfire determination process for determining that a misfire has occurred on a condition that the torque has decreased below a threshold set in advance. The ECU performs a retardation process for controlling an ignition timing toward a retardation side from the basic ignition timing when a state of the vehicle satisfies a condition determined in advance. A determination on the occurrence of a misfire based on a relationship in magnitude between the torque and the threshold is not made during the retardation process, in the misfire determination process.

An internal combustion engine of a vehicle is equipped with a plurality of cylinders, and ignition devices provided for the cylinders respectively. The vehicle is mounted with an ECU. The ECU performs an ignition timing decision process for deciding a basic ignition timing of the ignition devices in accordance with a load of the internal combustion engine. The ECU performs a misfire determination process for determining that a misfire has occurred on a condition that the torque has decreased below a threshold set in advance. The ECU performs a retardation process for controlling an ignition timing toward a retardation side from the basic ignition timing when a state of the vehicle satisfies a condition determined in advance. A determination on the occurrence of a misfire based on a relationship in magnitude between the torque and the threshold is not made during the retardation process, in the misfire determination process.

Methods and systems are provided for performing expansion combustion in an engine of a start-stop vehicle. In one example, a method may include, responsive to receiving an auto-start request to restart an engine from an auto-stop, determining a fuel mass to inject into a cylinder for an expansion combustion event based on a duration of the auto-stop, and actuating a spark plug of the cylinder after injecting the determined fuel mass to perform the expansion combustion event. In this way, an air-fuel ratio of the expansion combustion event may be more accurately controlled, resulting in more robust expansion combustion engine restarts.

Methods and systems are provided for performing expansion combustion in an engine of a start-stop vehicle. In one example, a method may include, responsive to receiving an auto-start request to restart an engine from an auto-stop, determining a fuel mass to inject into a cylinder for an expansion combustion event based on a duration of the auto-stop, and actuating a spark plug of the cylinder after injecting the determined fuel mass to perform the expansion combustion event. In this way, an air-fuel ratio of the expansion combustion event may be more accurately controlled, resulting in more robust expansion combustion engine restarts.

A system and method for a variable displacement internal combustion engine using different types of pneumatic cylinder springs on skipped working cycles to control engine and aftertreatment system temperatures are described. The system and method may be used to rapidly heat up the aftertreatment system(s) and/or an engine block of the engine following a cold start by using one or more different types of pneumatic cylinder springs during skipped firing opportunities. By rapidly heating the aftertreatment system(s) and/or engine block, noxious emissions such as hydrocarbons, carbon monoxide, NO.sub.x and/or particulates, following cold starts are significantly reduced.

A system and method for a variable displacement internal combustion engine using different types of pneumatic cylinder springs on skipped working cycles to control engine and aftertreatment system temperatures are described. The system and method may be used to rapidly heat up the aftertreatment system(s) and/or an engine block of the engine following a cold start by using one or more different types of pneumatic cylinder springs during skipped firing opportunities. By rapidly heating the aftertreatment system(s) and/or engine block, noxious emissions such as hydrocarbons, carbon monoxide, NO.sub.x and/or particulates, following cold starts are significantly reduced.

An engine control system includes: a normalization module configured to normalize, to within a predetermined range of values, a spark timing of an engine and at least one other parameter of the engine, thereby producing a normalized spark timing and at least one normalized other parameter, respectively; a processing module configured to generate a sigmoidal spark timing by applying, to the normalized spark timing, one of (a) a sigmoidal function and a sinusoidal function; and an estimation module configured to estimate a torque output of the engine based on the normalized spark timing and the at least one normalized other parameter using a mathematical model.