Abstract: A method for diagnosing a secondary-air system of an internal combustion engine. The secondary-air system introduces secondary air into the exhaust-gas region of the internal combustion engine, the secondary air exothermically reacting together with combustible exhaust-gas components, and a thermoreactor being formed in the reaction region. The method provides for a measure of the secondary air to be ascertained from the thermal behavior in the thermoreactor and evaluated. The measure of the secondary air, which reflects, for example, the volumetric flow rate of the secondary air, the mass flow rate of the secondary air, or the amount or mass of secondary air flowing in a time interval, is compared to at least one threshold value. At least one diagnostic signal is then generated as a function of the comparison result.

Abstract: A method for diagnosing a secondary-air system of an internal combustion engine. The secondary-air system introduces secondary air into the exhaust-gas region of the internal combustion engine, the secondary air exothermically reacting together with combustible exhaust-gas components, and a thermoreactor being formed in the reaction region. The method provides for a measure of the secondary air to be ascertained from the thermal behavior in the thermoreactor and evaluated. The measure of the secondary air, which reflects, for example, the volumetric flow rate of the secondary air, the mass flow rate of the secondary air, or the amount or mass of secondary air flowing in a time interval, is compared to at least one threshold value. At least one diagnostic signal is then generated as a function of the comparison result.

Abstract: An internal combustion engine (10) is operated by a method wherein the fuel is supplied via a magnetic valve (28) having a coil (34). The injected fuel quantity is influenced by the duration of the drive of the magnetic valve (28). In the method, the temperature (evtmod) of a region (26) of the magnetic valve (28) is determined and the drive duration is corrected in dependence upon temperature. In order to make the correction still more precise, a temperature (evtmod) of the magnetic valve (28) is determined from at least one usually measured temperature (tans, tmot) and the drive duration (ti_tvu_w) is so corrected (tvsp_w) that the temperature dependency of the characteristics of the magnetic coil (34) of the magnetic valve (28) is considered. Furthermore, a model is suggested in which (starting from an operating temperature) the temperature trace is simulated after shut-off of the engine and/or for the restart of the engine by means of two factors for the warmup and cool down.

Abstract: A method is presented for positioning a measurement window in time for analysis of ionic current signals, detected at internal combustion engines via the electrodes of a spark plug, for an ignition system having an ignition transformer, e.g., a.c. ignition or in a capacitor ignition system or inductive transistor ignition or inductive coil ignition or inductive coil ignition having a limited spark duration, the ignition systems being combined with a measurement device for an ionic current at the secondary winding on the ground side, each spark plug being allocated one ignition transformer, and the detection of the end of a spark and the opening of the measurement window for the ionic current signal taking place as a function of the end of the spark.

Abstract: A method and a device for controlling an output variable of a drive unit in the starting phase is described. A controller is provided, regulating the actual value of at least one output variable to a setpoint variable of this output variable which is specified as a function of time. When at least one condition marking entry into the starting phase exists, the setpoint value of the output variable is initialized with the actual value of the output variable.

Abstract: An internal combustion engine (10) is operated by a method wherein the fuel is supplied via a magnetic valve (28) having a coil (34). The injected fuel quantity is influenced by the duration of the drive of the magnetic valve (28). In the method, the temperature (evtmod) of a region (26) of the magnetic valve (28) is determined and the drive duration is corrected in dependence upon temperature. In order to make the correction still more precise, a temperature (evtmod) of the magnetic valve (28) is determined from at least one usually measured temperature (tans, tmot) and the drive duration (ti_tvu_w) is so corrected (tvsp_w) that the temperature dependency of the characteristics of the magnetic coil (34) of the magnetic valve (28) is considered. Furthermore, a model is suggested in which (starting from an operating temperature) the temperature trace is simulated after shut-off of the engine and/or for the restart of the engine by means of two factors for the warmup and cool down.

Abstract: The invention relates to an inductive ignition device for an internal combustion engine, having an ignition coil (ZS) with a primary coil (L1) and a secondary coil (L2), wherein a diode (D) is provided on the side of the secondary coil (L2), having a spark plug (ZK) with at least one electrode, and having a measuring device for detecting an ionic current (14). A shunt device (16) is provided in order to decrease a residual charge that is present between the diode (D) and an electrode of the spark plug (ZK). The shunt device (16) preferably contains a high-impedance resistance (R) connected in parallel with the diode (D). This permits a reliable detection of combustion misses in the ionic current signal.

Abstract: The invention relates to a method for controlling an electrically heatable catalytic converter for after-treating exhaust gases of an internal combustion engine. The catalytic converter is deactivated or not activated during the start of the engine if the temperature (TKAT(tabst)) of the catalytic converter exceeds a critical temperature TKRIT when starting the engine. The temperature (TKAT(tabst)) of the catalytic converter is estimated via a temperature model. The invention also relates to an exhaust-gas after-treatment system of an internal combustion engine for carrying out the method of the invention.

Abstract: A device and a method for detecting phase in four-stroke engines, in which an electronic control unit (ECU) detects a spark current as a measuring signal and determines whether ignition occurred for ascertaining the compression cycles of the cylinders, whereby the electronic control unit is able to cause the injection to be performed in a correct phase relation.

Abstract: A method and a device for controlling an output variable of a drive unit in the starting phase is described. A controller is provided, regulating the actual value of at least one output variable to a setpoint variable of this output variable which is specified as a function of time. When at least one condition marking entry into the starting phase exists, the setpoint value of the output variable is initialized with the actual value of the output variable.

Abstract: A method and an arrangement for detecting combustion misfires in internal combustion engines are presented where a measured ionic current signal is subjected to a floating short-time integration and a feature is formed which corresponds to the maximum value of the floating short-time integrator within the entire measuring window. The window length of the short-time integrator is shorter than the total measuring window and is floatingly displaced over the measuring window.

Abstract: A method and an arrangement for energy control on an ignition system for an internal combustion engine are presented having an ignition coil or an ignition transformer whose primary winding can be short circuited by means of a switch, called a short-circuit switch, the ignition coil forming the ignition voltage and having a primary winding and a secondary winding, and, an ion current can be measured with the secondary winding of the ignition coil by means of one or several spark plugs, the primary current in the short-circuit phase of the short-circuit switch is detected with a suitable means and is transmitted to the control unit, the measurement quantity is processed in the form of a function or filtering in the control unit after actuation of the short-circuit switch and an energy control via closure time or closure angle is built up with the obtained feature.

Abstract: A method for processing the ion flow signals of internal combustion engines by offset correction, masking and multiplexing for engine control functions wherein, after the measurement of the ion flow signal in each cylinder for the purpose of offset correction in advance of each ignition operation, the level of the measurement signal of the cylinder is detected; during masking operation, the measurement signal is substituted in a second signal by the level value and is subtracted from the second signal until the next ignition operation and thereafter, the channels which are to be multiplexed, are combined to a third signal by the addition of the second signals of the particular cylinders, the second signal being derived from the measurement signal.