A method, system, and engine are configured to determine a parameter based on rotational speeds of a crankshaft, over at least three cylinder combustion cycles. The method, system, and engine determine two or more estimated crankshaft rotational speeds at two or more positions in a leading cylinder combustion cycle, two or more estimated crankshaft rotational speeds at two or more positions in a middle cylinder combustion cycle, and two or more estimated crankshaft rotational speeds at two or more positions in a following cylinder combustion cycle. The method, system, and engine are configured to determine a calculated metric based on each of the determined leading estimated crankshaft rotational speeds, the determined middle estimated crankshaft rotational speeds, and the determined following estimated crankshaft rotational speeds. An engine parameter, such as misfire, is then determined based on the calculated metric.

A method, system, and engine are configured to determine a parameter based on rotational speeds of a crankshaft, over at least three cylinder combustion cycles. The method, system, and engine determine two or more estimated crankshaft rotational speeds at two or more positions in a leading cylinder combustion cycle, two or more estimated crankshaft rotational speeds at two or more positions in a middle cylinder combustion cycle, and two or more estimated crankshaft rotational speeds at two or more positions in a following cylinder combustion cycle. The method, system, and engine are configured to determine a calculated metric based on each of the determined leading estimated crankshaft rotational speeds, the determined middle estimated crankshaft rotational speeds, and the determined following estimated crankshaft rotational speeds. An engine parameter, such as misfire, is then determined based on the calculated metric.

An ECU outputs an ignition signal Si to an ignition apparatus through an ignition communication line, and outputs a discharge waveform control signal Sc with a logic H through a waveform control communication line. The ignition apparatus performs the closing operation of an ignition switching element, in a period during which the ignition signal Si is input. In an input period of the discharge waveform control signal Sc after stopping the input of the ignition signal Si, the ignition apparatus controls the electric current to flow through a primary coil, by the opening-closing operation of a control switching element. When the voltage of the waveform control communication line Lc is the logic H in an output stop period of the discharge waveform control signal Sc, the ECU determines that the waveform control communication line is abnormal, and executes a fail-safe process.

An ECU outputs an ignition signal Si to an ignition apparatus through an ignition communication line, and outputs a discharge waveform control signal Sc with a logic H through a waveform control communication line. The ignition apparatus performs the closing operation of an ignition switching element, in a period during which the ignition signal Si is input. In an input period of the discharge waveform control signal Sc after stopping the input of the ignition signal Si, the ignition apparatus controls the electric current to flow through a primary coil, by the opening-closing operation of a control switching element. When the voltage of the waveform control communication line Lc is the logic H in an output stop period of the discharge waveform control signal Sc, the ECU determines that the waveform control communication line is abnormal, and executes a fail-safe process.

A system for detecting spark plug failures in an engine is provided. The system may include one or more sensor devices coupled to the engine and configured to measure engine data, a controller in communication with the sensor devices, and an output device. The controller may be configured to determine at least a misfire count, a secondary transformer voltage, and an exhaust port temperature based on the engine data, identify a fault condition based on one or more of the misfire count, the secondary transformer voltage, and the exhaust port temperature, and perform a corrective action responsive to the fault condition. The output device may be configured to generate a notification corresponding to the fault condition.

A system for detecting spark plug failures in an engine is provided. The system may include one or more sensor devices coupled to the engine and configured to measure engine data, a controller in communication with the sensor devices, and an output device. The controller may be configured to determine at least a misfire count, a secondary transformer voltage, and an exhaust port temperature based on the engine data, identify a fault condition based on one or more of the misfire count, the secondary transformer voltage, and the exhaust port temperature, and perform a corrective action responsive to the fault condition. The output device may be configured to generate a notification corresponding to the fault condition.

A semiconductor apparatus is provided, comprising: a power semiconductor element which is connected between a first terminal on a high-potential side and a second terminal on a low-potential side; a first gate control section which controls a gate potential of the power semiconductor element according to a control signal; a discharge circuit which is discharges charges that are charged by the gate of the power semiconductor element; a second gate control section which controls the gate potential of the power semiconductor element according to a collector current of the power semiconductor element; a feedback section which feedbacks the charges to the gate of the power semiconductor element according to the collector potential of the power semiconductor element; and a current cutting off section which cuts off currents flowing from the first terminal to the gate of the power semiconductor element according to the control signal.

A method for preventing back fire of an engine by a device for preventing back fire of an engine, may include monitoring operating information of the engine; determining whether the back fire occurs by using the operating information of the engine; and controlling an ignition timing to be retarded when the back fire occurs as the determination result.

A method for preventing back fire of an engine by a device for preventing back fire of an engine, may include monitoring operating information of the engine; determining whether the back fire occurs by using the operating information of the engine; and controlling an ignition timing to be retarded when the back fire occurs as the determination result.

An ignition control apparatus of the present embodiment controls operation of an ignition plug provided so as to ignite an air-fuel mixed gas. The ignition control apparatus is characterized in that the ignition control apparatus includes: an ignition coil provided with a primary winding which allows a current to pass as a primary current therethrough and a second winding connected to the ignition coil, an increase and a decrease in the primary current generating a secondary current passing through the secondary winding; a DC power supply provided with a non-ground side output terminal, the non-ground side output terminal being connected to one end of the primary winding so that the primary current is made to pass through the primary winding; a first switching element configured of a semiconductor switching element provided with a first control terminal, a first power side terminal, and a first ground side terminal, the semiconductor switching element controlling on and off states of current supply between the first power side terminal and the first ground side terminal based on a first control signal inputted to the first control terminal, the first power side terminal being connected to the other end side of the primary winding, the first ground side terminal being connected to a ground side; a second switching element configured of a semiconductor switching element provided with a second control terminal, a second power side terminal, and a second ground side terminal, the semiconductor switching element controlling on and off states of current supply between the second power side terminal and the second ground side terminal based on a second control signal inputted to the second control terminal, the second ground side terminal being connected to the other end side of the primary winding; a third switching element configured of a semiconductor switching element provided with a third control terminal, a third power side terminal, and a third ground side terminal, the semiconductor switching element controlling on and off states of current supply between the third power side terminal and the third ground side terminal based on a third control signal inputted to the third control terminal, the third power side terminal being connected to the second power side terminal of the second switching element, the third ground side terminal being connected to the ground side; and an energy accumulation coil configured of an inductor, the inductor being interposed in a power line connecting the non-ground side output terminal of the DC power supply and the third power side terminal of the third switching element, the energy accumulation coil accumulating energy ther