Abstract: A method is provided for reducing emissions behind a catalytic converter in an exhaust gas stream of the engine. The method includes, but is not limited to controlling a power supply to a glowplug of a compression-ignition engine. The glowplug is activated if a set of at least two input values remains in a first characteristic region of an input parameter space for at least a predetermined activation time. The first characteristic region consists of one ore more contiguous regions of the input parameter space.

Abstract: A method is provided that includes, but is not limited to estimating the temperature (TGP,est) of the glow-plug (GP) in accordance with a first model of the glow-plug (GP) as a function of the detected values of the glow-plug voltage and current (VGP, IGP) and the sensed values of some input variables, such as the engine speed (?E) and the engine temperature (TE), determining, in accordance with a second predetermined model of the glow-plug (GP), a desired value of the voltage (VGP,des) or power (PGP,des) to be supplied to the glow-plug (GP), as a function of a desired value of the glow-plug temperature (TGP,des), the estimated glow-plug temperature (TGP,est), and the sensed values of the input variables, and varying the duty-cycle of a pulse-width-modulated voltage (VPWM) applied to the glow-plug (GP), as a function of the calculated value of said desired voltage (VGP,des) or power (PGP,des).

Abstract: A glow plug control unit is provided that includes a first switch for connecting power supply lines to a glow plug. The glow plug control unit further includes a voltage measurement unit for measuring the voltage at the power supply lines. A current measurement unit is built for measuring the current through the first switch and a control circuit is built for controlling the first switch and, in a current control mode, for regulating the current through the first switch.

Abstract: A method is provided for reducing emissions behind a catalytic converter in an exhaust gas stream of the engine. The method includes, but is not limited to controlling a power supply to a glowplug of a compression-ignition engine. The glowplug is activated if a set of at least two input values remains in a first characteristic region of an input parameter space for at least a predetermined activation time. The first characteristic region consists of one ore more contiguous regions of the input parameter space.

Abstract: A method is provided that includes, but is not limited to estimating the temperature (TGP,est) of the glow-plug (GP) in accordance with a first model of the glow-plug (GP) as a function of the detected values of the glow-plug voltage and current (VGP, IGP) and the sensed values of some input variables, such as the engine speed (?E) and the engine temperature (TE), determining, in accordance with a second predetermined model of the glow-plug (GP), a desired value of the voltage (VGP,des) or power (PGP,des) to be supplied to the glow-plug (GP), as a function of a desired value of the glow-plug temperature (TGP,des), the estimated glow-plug temperature (TGP,est), and the sensed values of the input variables, and varying the duty-cycle of a pulse-width-modulated voltage (VPWM) applied to the glow-plug (GP), as a function of the calculated value of said desired voltage (VGP,des) or power (PGP,des).

Abstract: A glow plug control unit is provided that comprises a first switch for connecting power supply lines to a glow plug. The glow plug control unit further comprises a voltage measurement unit for measuring the voltage at the power supply lines. A current measurement unit is built for measuring the current through the first switch and a control circuit is built for controlling the first switch and, in a current control mode, for regulating the current through the first switch.