Abstract: A system and method for controlling knock in a lean burn internal combustion (IC) engine includes a spark plug having an electrode, and an electrical circuit configured to provide a first voltage to the electrode and detect an ion current during a thermal-ionization phase of the combustion process, and provide a second voltage to the electrode to create a spark and initiate a combustion process within a combustion chamber. The engine includes a controller configured to monitor the ion current for a knock condition that includes at least an incipient knock condition, determine a spark crank angle timing of the IC engine where the incipient knock occurs, and adjust the spark timing of the IC engine to operate at a crank angle that does not exceed a threshold level beyond an incipient knock set point.

Abstract: A system and method for controlling knock in a lean burn internal combustion (IC) engine includes a spark plug having an electrode, an electrical circuit, and a controller. The electrical circuit is configured to provide a first voltage to the electrode and detect an ion current during a thermal-ionization phase of the combustion process, and provide a second voltage to the electrode to create a spark and initiate a combustion process within the combustion chamber. The controller is configured to monitor the ion current for a knock condition that includes at least an incipient knock condition, determine a crank angle of the IC engine where the incipient knock occurs, and adjust timing of the IC engine to operate at a crank angle that does not exceed a threshold level beyond inception of incipient knock.

Abstract: A system and method for controlling knock in a lean burn internal combustion (IC) engine includes a spark plug having an electrode, and an electrical circuit configured to provide a first voltage to the electrode and detect an ion current during a thermal-ionization phase of the combustion process, and provide a second voltage to the electrode to create a spark and initiate a combustion process within a combustion chamber. The engine includes a controller configured to monitor the ion current for a knock condition that includes at least an incipient knock condition, determine a spark crank angle timing of the IC engine where the incipient knock occurs, and adjust the spark timing of the IC engine to operate at a crank angle that does not exceed a threshold level beyond an incipient knock set point.

Abstract: A system and method for controlling knock in a lean burn internal combustion (IC) engine includes a spark plug having an electrode, an electrical circuit, and a controller. The electrical circuit is configured to provide a first voltage to the electrode and detect an ion current during a thermal-ionization phase of the combustion process, and provide a second voltage to the electrode to create a spark and initiate a combustion process within the combustion chamber. The controller is configured to monitor the ion current for a knock condition that includes at least an incipient knock condition, determine a crank angle of the IC engine where the incipient knock occurs, and adjust timing of the IC engine to operate at a crank angle that does not exceed a threshold level beyond inception of incipient knock.

Abstract: A method and apparatus to maximize spark plug life in pre-chamber spark plugs operating with ultra-lean mixtures and/or elevated engine BMEP is presented. Electrode erosion is reduced by spreading discharge energy over a wider surface area, maintaining fuel concentration in the spark gap, controlling gas static pressure during discharge, and maintaining safe electrode temperature. Energy is spread via a swirling effect created by periphery holes in an end cap, resulting in a lower specific energy discharge at the electrodes. Divergently configured electrodes reduce the spark voltage at high operating pressures and the energy required for ignition. The flow field generated at the electrodes prevents electrical shorts due to water condensation and avoids misfire. The center electrode insulation provides an effective heat transfer path to prevent electrode overheating and preignition.

Abstract: An apparatus and method to sense the onset of combustion stability is presented. An electrode is positioned in a turbine combustion chamber such that the electrode is exposed to gases in the combustion chamber. The electrode may be integrated with an igniter. A control module applies a voltage potential to the electrode and detects a combustion ionization signal and determines if there is an oscillation in the combustion ionization signal indicative of the occurrence of combustion stability or the onset of combustion instability. The control module broadcasts a notice if the parameters indicate the combustion process is at the onset of combustion instability or broadcasts an alarm signal if the parameters indicate the combustion process is instable. Combustion parameters are adjusted to drive the combustion process towards stability.

Abstract: An apparatus and method to detect combustion conditions using ion signals for use in a feedback control of a diesel engine is presented. The apparatus is a spark plug type of sensor or a sensor integrated with a fuel injector. The spark plug type of sensor is used to provide a cold start mechanism combined with an ion sensing device.

Abstract: An apparatus and method for generating a highly conductive channel for the flow of plasma current between the electrodes of an ignitor gap device are disclosed. A high voltage transformer having a high turns ratio is used to produce a high voltage spark across an ignitor gap. Subsequently, a high voltage low turns ratio transformer is used to supply a pre-plasma current signal to the ignitor gap at a predetermined time following the high voltage spark thereby ensuring that the ionized channel is developed to a more conductive state prior to introduction of the pre-plasma signal into the ignitor gap. Once the sustaining voltage for sustaining plasma flow through the channel has stabilized to a sufficiently low voltage, a high current main plasma signal is supplied to the ignitor gap thereby expanding plasma flow in the area surrounding the ignitor gap and providing a high quality ignition source for use in internal combustion engines.

Abstract: A plasma jet ignitor apparatus for generating plasma from a plasma medium and for discharging the plasma as a jet into the combustion chamber of an internal combustion engine. The apparatus has a plug which has electrodes from which an arc is generated. The arc causes the plasma medium which is supplied to the plasma generation cavity to become plasma. The plasma generation cavity is cooperatively arranged with magnetic field generation means, electrode discharging means and plasma medium supply means. The cavity has an inlet opening adjacent the plasma generation location at the bottom of the cavity and an outlet orifice at the top of the cavity. The plasma is ejected as a plasma jet, with a ring vortex structure, from the cavity and through the orifice. The magnetic field generation means is disposed as a magnetic field coil acting on the arc. The magnetic field is created by the discharge of a capacitor at the time of the formation of the plasma in the cavity.

Abstract: A plasma jet ignitor apparatus for generating plasma from a plasma medium such as hydrogen and for discharging the plasma as a jet into the combustion chamber of an internal combustion engine. The apparatus has a plug which has an electrode from which a high energy spark is generated. The spark causes hydrogen which is introduced into the plasma generation cavity by a fuel line to become plasma. The plasma generation cavity is defined by magnetic field generation means. The cavity has an inlet opening adjacent the plasma generation location and an outlet orifice. The plasma is ejected as a plasma jet from the cavity from the orifice. The magnetic field generation means is disposed as a magnetic field coil wound about the cavity. The magnetic field is charged by the discharge of a capacitor at the time of the formation of the plasma in the cavity. The magnetic field accelerates the plasma out of the cavity through the orifice so that the plasma exits as a high velocity jet and achieves effective penetration.

Abstract: A plasma jet ignitor apparatus for generating plasma from a plasma medium such as hydrogen and for discharging the plasma as a jet into the combustion chamber of an internal combustion chamber. The apparatus has a plug which has an electrode from which a high energy spark is generated. The spark causes hydrogen which is introduced into the plasma generation cavity by a fuel line to become plasma. The plasma generation cavity is defined by magnetic field generation means. The cavity has an inlet opening adjacent the plasma generation location and an outlet orifice. The plasma is ejected as a plasma jet from the cavity from the orifice. The magnetic field generation means is disposed as a magnetic field coil wound about the cavity. The magnetic field is charged by the discharge of a capacitor at the time of the formation of the plasma in the cavity. The magnetic field accelerates the plasma out of the cavity through the orifice so that the plasma exits as a high velocity jet and achieves effective penetration.