In an engine including an auxiliary chamber having an ignition plug therein, an amount of heat generated in the auxiliary chamber tends to be large, and thus it is necessary to suppress abnormal combustion. However, when a sensor is added to the ignition plug, a manufacturing cost of the ignition plug tends to increase. An ECU 2 includes an auxiliary chamber temperature estimation unit 21 that estimates a temperature of the auxiliary chamber 42, and an ignition control unit 22 that delays an ignition timing at a first decrease degree defined in accordance with a change amount of the ignition timing with respect to the temperature of the auxiliary combustion chamber as the temperature of the auxiliary chamber 42 increases in a case where the estimated temperature of the auxiliary chamber 42 is included in a middle temperature region equal to or lower than a first set temperature.

In an engine including an auxiliary chamber having an ignition plug therein, an amount of heat generated in the auxiliary chamber tends to be large, and thus it is necessary to suppress abnormal combustion. However, when a sensor is added to the ignition plug, a manufacturing cost of the ignition plug tends to increase. An ECU 2 includes an auxiliary chamber temperature estimation unit 21 that estimates a temperature of the auxiliary chamber 42, and an ignition control unit 22 that delays an ignition timing at a first decrease degree defined in accordance with a change amount of the ignition timing with respect to the temperature of the auxiliary combustion chamber as the temperature of the auxiliary chamber 42 increases in a case where the estimated temperature of the auxiliary chamber 42 is included in a middle temperature region equal to or lower than a first set temperature.

It is disclosed an electronic device to control an ignition coil of an internal combustion engine, comprising a high-voltage switch, a driving unit, a bias circuit and an integrating circuit. The high-voltage switch is connected in series with a primary winding of a coil. The driving unit is configured to control the closing and opening of the high-voltage switch. The integrating circuit is interposed between the bias circuit and a reference voltage. The integrating circuit comprises an integrating capacitor. The integrating capacitor is configured, in the case wherein a pre-ignition of the comburent-combustible mixture in the combustion chamber during the phase of charging occurs, to pre-charge during the phase of charging energy in the primary winding and it is configured, in the case wherein the pre-ignition of the comburent-combustible mixture does not occur, to maintain the charge state substantially constant during the phase of charging energy.

A system and method for assessing the presence or absence of ignition coil degradation for an ignition system that includes two ignition coils for each spark plug. Ignition coil degradation may be determined without having to monitor ignition coils via specialized hardware circuitry. In one example, degradation of one or more ignition coils may be inferred from cylinder the presence or absence of cylinder misfire.

The objective is to provide an internal-combustion-engine controller that can diagnose, at low cost and in real time, respective combustion states of a subsidiary-chamber-type internal combustion engine. An internal-combustion-engine controller according to the present disclosure controls an internal combustion engine having a main combustion chamber and a subsidiary combustion chamber from which a combustion gas is injected into the main combustion chamber through an orifice provided between the main combustion chamber and the subsidiary combustion chamber to ignite a fuel-air mixture in the main combustion chamber; the internal-combustion-engine controller includes an ion detector that detects an ion in the in the subsidiary combustion chamber and a diagnosis and control device that controls fuel supply to the internal combustion engine and diagnoses a combustion state in the main combustion chamber or in the subsidiary combustion chamber, based on an amount of an ion detected by the ion detector.

The ignition control device includes a spark plug that includes a first electrode and a second electrode disposed so as to oppose each other, an ignition coil that includes a plurality of sets of a primary coil and a secondary coil, generates a high voltage in the secondary coil by energizing or interrupting a primary current supplied to the primary coil, and applies the generated high voltage to the first electrode, and a control unit that, in a case where a plurality of the primary coils are driven during a single ignition process, temporarily stops energization of a primary current supplied to a second primary coil when a primary current supplied to a first primary coil is interrupted, and re-energizes the primary current supplied to the second primary coil following the elapse of an energization stoppage period.

A method for ignition control in a combustion chamber of an internal combustion engine by means of acquiring an electric signal relating to ionizing currents emitted in said combustion chamber, comprising a step of detecting a substantially stepped trend of said electric signal and a consequent step of inhibiting a corrective action of an ignition advance and/or of a fuel injection limitation curve in the combustion chamber.

An ion current detection circuit is for detecting an ion current flowing through a spark plug for an internal combustion engine. A detection terminal is to be electrically connected to the spark plug. A reference potential is to be supplied to a reference terminal. At least one protection diode is provided between the detection terminal and the reference terminal. A current detection unit causes a detection current to flow between the detection terminal and the at least one protection diode. A current compensation unit causes a compensation current to flow between the detection terminal and the at least one protection diode.

A method for monitoring an engine cylinder in an internal combustion engine includes, for each engine cycle, detection of the ionisation current generated in the cylinder in a predetermined time interval of a combustion cycle, generation of a signal representing the ionisation current and comparing a maximum value of the signal with a threshold value. Successively, the value of one or more parameters associated with the signal can be changed with respect to an equal number of corresponding reference values when the maximum value of the signal exceeds the threshold value, to reduce the maximum value of the signal in the time interval of a successive combustion cycle. The presence of water in the cylinder can be determined when the maximum value of the signal exceeds the threshold value for a predetermined first number of combustion cycles occurring within a predetermined period of time.

An electronic device for controlling an ignition coil of an internal combustion engine includes a high voltage switch, a driving unit and a control unit. The driving unit controls the closure of the switch during charging energy in the primary winding and the opening of the switch during transferring energy from the primary winding to a secondary winding. A current measuring circuit is connected in series to a second terminal of the secondary winding to detect current generated on the secondary winding during the charging step and generate a signal representative of the detected current. The control unit receives the signal representative of the current detected by the measuring circuit, compares a relevant value of such signal with a predefined first reference value and activates a mode for detecting a soiling of the spark plug when the relevant value of the signal exceeds said predefined first reference value.