A method for evaluating the compression of the cylinders of an internal combustion engine of a vehicle having an electric starter motor and a respective starting battery, comprising: start capturing the battery voltage signal when the starter motor stars to rotate the internal-combustion engine so as to initiate operation of the engine under its own power; cease capturing the battery voltage signal when the engine enters operation under its own power; process the captured voltage signal for the location of local minimums; calculate the time difference between consecutive local minimums; detect if there is a variation of time between the calculated differences higher than a predetermined threshold between any said calculated time differences; and, if there is such variation, signal a potential engine malfunction. Also provided is a device for accomplishing the foregoing.

The present disclosure relates to a method for detecting and distinguishing a cause of at least one combustion misfire of an internal combustion engine. The internal combustion engine has several cylinders, at least one exhaust gas tract, and an exhaust gas sensor which is arranged in the exhaust gas tract. The method includes the following steps: acquisition of a measurement signal with the exhaust gas sensor over a certain first period of time gas tract; subdivision of the measurement signal into measurement signal sections; assignment of the measurement signal sections to the corresponding cylinders, whereby cylinder-selective measurement signal profiles are produced that are characteristic of the respective oxygen content downstream of the respective cylinders over the determined first period of time of time; and evaluation of the cylinder-selective measurement signal profiles to detect at least one combustion misfire of the internal combustion engine.

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.

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.

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.

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.

Energization abnormality of a switch element of an internal combustion engine ignition device is detected appropriately. To this end, in an internal combustion engine ignition device that includes an ignition coil and an ignition plug, the ignition coil includes a primary coil including a main primary coil and a sub primary coil and a secondary coil that generates secondary current in response to a voltage variation generated in the primary coil. The internal combustion engine ignition device includes a main switch element that performs energization/deenergization of the main primary coil in a first direction, a sub primary coil magnetic flux generation state switching unit capable of switching between a forward direction magnetic flux generation state in which energization of the sub primary coil in the first direction is performed and an opposite direction magnetic flux generation state in which energization of the sub primary coil in a second direction is performed, and an abnormality detection section that detects energization abnormality to the sub primary coil. The abnormality detection section is configured so as to detect energization abnormality on the basis of overlap between energization in the first direction and energization in the second direction of the sub primary coil.

The invention relates to a method for operating an internal combustion engine with fuel which is combusted using a spark plug. According to the invention, the aging of the spark plug, in particular the aging of an electric resistor of the spark plug, is monitored during the operation of the internal combustion engine, wherein electromagnetic radiation of the spark plug is detected for monitoring purposes. The invention additionally relates to a controller for carrying out the method.

The objective is to provide an internal-combustion-engine controller that can diagnose a smolder state in a subsidiary combustion chamber of a subsidiary-chamber-type internal combustion engine at low cost and in real time and that can perform control so as to securely produce a spark discharge. The controller controls an internal combustion engine in which a fuel-air mixture in the main combustion chamber is ignited with combustion gas to be injected through an orifice provided in a subsidiary combustion chamber; the controller includes an ignition plug and a detection probe arranged in the subsidiary combustion chamber, an ignition coil, a fuel injector, a smolder detector, and a smolder diagnosis device, and controls at least one of the ignition coil and the fuel injector in accordance with a diagnostic result in the smolder diagnosis device.

The objective is to provide an internal-combustion-engine controller that can diagnose a smolder state in a subsidiary combustion chamber of a subsidiary-chamber-type internal combustion engine at low cost and in real time and that can perform control so as to securely produce a spark discharge. The controller controls an internal combustion engine in which a fuel-air mixture in the main combustion chamber is ignited with combustion gas to be injected through an orifice provided in a subsidiary combustion chamber; the controller includes an ignition plug and a detection probe arranged in the subsidiary combustion chamber, an ignition coil, a fuel injector, a smolder detector, and a smolder diagnosis device, and controls at least one of the ignition coil and the fuel injector in accordance with a diagnostic result in the smolder diagnosis device.