An ignition control device includes an ignition coil, a main ignition circuit unit for performing a main ignition operation, and an energy input circuit unit for performing an energy input operation. A main ignition signal generation circuit generates a main ignition signal such that a point in time when a waiting time has passed from a detection start time of a first signal of an ignition control signal at which a signal level of the ignition control signal changed from a first level to a second level for the first time, and the signal level of the ignition control signal is the second level, is a start of the main ignition signal, and a detection end time of a second signal of the ignition control signal at which the signal level of the ignition control signal shifts to the first level thereafter is an end of the main ignition signal.

Due to changes in a flow of an air-fuel mixture in a cylinder, reliable ignition due to spark discharge may not be possible. Therefore, an ignition control unit 24 includes a secondary voltage calculation unit 31 that calculates an average value of a secondary voltage generated on a secondary side of an ignition coil, an irregular flow ratio calculation unit 32 that calculates a ratio of cycles in which the average value of the secondary voltage is equal to or less than a set average value with respect to a cycle of the internal combustion engine in a predetermined period as an irregular flow ratio indicating that the flow of the air-fuel mixture in the cylinder is irregular, and an ignition operation amount correction unit 37 that corrects an ignition operation amount so that the irregular flow ratio is equal to or less than the set ratio value that is the target to be reached of the irregular flow ratio.

Due to changes in a flow of an air-fuel mixture in a cylinder, reliable ignition due to spark discharge may not be possible. Therefore, an ignition control unit 24 includes a secondary voltage calculation unit 31 that calculates an average value of a secondary voltage generated on a secondary side of an ignition coil, an irregular flow ratio calculation unit 32 that calculates a ratio of cycles in which the average value of the secondary voltage is equal to or less than a set average value with respect to a cycle of the internal combustion engine in a predetermined period as an irregular flow ratio indicating that the flow of the air-fuel mixture in the cylinder is irregular, and an ignition operation amount correction unit 37 that corrects an ignition operation amount so that the irregular flow ratio is equal to or less than the set ratio value that is the target to be reached of the irregular flow ratio.

A spark plug heat up method via transient control of the spark discharge current. The high temperature plasma channel is used to heat up the central electrode, and the temperature and energy of the plasma channel are realized via transient control of the discharge current. The heating up process takes place before firing the engine, using discharge current to actively heat up the spark plug from inside. By monitoring the discharge current amplitude and discharge duration, the temperature change of the central electrode and the ceramic insulator can be carefully measured and controlled within a proper window. This method can be used to measure the heating range of the spark plug, and to prevent or remove the carbon deposit on the central electrode and the ceramic insulator generated under various engine operation conditions, such as engine cold start, full load operation, and heavy EGR condition, as well as realize self-cleaning.

Methods and systems are provided for operating a cylinder with a series gap igniter coupled to an ion sensing module. In one example, a method may include determining a location of an initial combustion in a cylinder from a series gap igniter based on a pressure rise rate in the cylinder, the ignition spark initiating combustion in the cylinder; and adjusting at least one setting of the cylinder based on the determined location. In this way, combustion stability and efficiency may be increased without increasing a cost and complexity of the engine.

In an ignition control device for an internal-combustion engine, signal separation circuitry receives and separates an ignition control signal that is an integrated signal of a main ignition signal for controlling the main ignition operation, an energy input signal for controlling the energy input operation, and a target secondary current command signal. The ignition control signal is formed of a first signal and a second signal that are pulsed signals. The signal separation circuitry is configured to generate, from the ignition control signal, the main ignition signal based on rising edges of the first signal and the second signal as pulse-waveform information of the first signal and the second signal, generate the energy input signal based on a pulse width of the second signal as pulse-waveform information of the second signal, and generate the target secondary current command signal based on pulse-waveform information of the first signal.

An electrode wear amount predicting system of a spark plug, includes: at least one ignition coil that includes a primary coil and a secondary coil; a spark plug that generates a spark discharge by a discharge current generated by the ignition coil and includes a center electrode and a ground electrode; a sensing portion measuring a current applied to the primary coil; and a controller that determines a wear state of the center electrode and the ground electrode according to an amount of the current applied to the primary coil detected by the sensing portion when an electrode wear amount predicting condition is satisfied.

An electrode wear amount predicting system of a spark plug, includes: at least one ignition coil that includes a primary coil and a secondary coil; a spark plug that generates a spark discharge by a discharge current generated by the ignition coil and includes a center electrode and a ground electrode; a sensing portion measuring a current applied to the primary coil; and a controller that determines a wear state of the center electrode and the ground electrode according to an amount of the current applied to the primary coil detected by the sensing portion when an electrode wear amount predicting condition is satisfied.

A current control circuit for an ignition system (i.e., igniter current limiter) is disclosed. The current control circuit can reduce a coil current over a soft shut down (SSD) period using an insulated gate bipolar transistor (IGBT) that is controlled by a negative feedback loop, which controls the current limit of the IGBT according to a SSD profile. In order to prevent an unwanted current rise during the soft shut down period, the current control circuit compares a gate voltage of the IGBT to a reference signal and based on the comparison can enable the SSD profile to include a fast ramp. The fast ramp quickly lowers the current limit of the IGBT so that the coil current equals the current limit and can be controlled by the negative feedback loop.

Disclosed is an ignition drive module with stable performance and reliable function, which comprises a module signal input end, a voltage input end, a module signal output end, a comparator connected to the module signal input end a maximum dwell timer module connected to the comparator, a logical judgment module connected to the comparator, and an insulated gate bipolar transistor connected to the logical judgment module. The logical judgment module receives signals from the maximum dwell timer module and the comparator to determine whether to activate the insulated gate bipolar transistor. The output end of the insulated gate bipolar transistor is connected to the module signal output end.