Volkswagen Ag

Volkswagen Aktiengesellshaft

Volkwagen Ag

Omg Ag & Co Kg

Volksawagen Aktiengesellschaft

Hermann Hahn

Sören Hinze

Ekkehard Pott

Michael Daetz

Ulrich Goebel

Axel Lang

Michael Lindlau

S&ouml;ren Hinze

Juergen Hoehne

Norbert Pelz

Andreas Berns

Gerrit Bruns

A control device controls a heating device for heating a component, in particular a lambda sensor. The method comprises the cyclically repeating steps: operating the heating device at a heating voltage, ascertaining a current heating voltage (U_H_a) of the heating device, ascertaining a mean heating voltage (U_H_m) for a predetermined, immediately preceding period of time, determining a maximum permissible heating period (T_max) for which the component may be heated for the maximum length of time using the current heating voltage (U_H_a) or using the mean heating voltage (U_H_m), in dependence upon the mean heating voltage (U_H_m), comparing the current heating voltage (U_H_a) and the mean heating voltage (U_H_m) with a predetermined minimum heating voltage (U_H_min), and reducing the heating voltage of the heating device if the current heating voltage (U_H_a) and/or the mean heating voltage (U_H_m) exceeds the predetermined minimum heating voltage (U_H_min) for the duration of the maximum permissible heating period (T_max).

Method for controlling a heating device for heating a component, control device and motor vehicle with same

The invention relates to a method and to a regulating device for regulating an air-fuel ratio of an internal combustion engine (), wherein an exhaust-gas composition of an exhaust gas of the internal combustion engine () is determined by virtue of an actual probe signal, which is dependent on the exhaust-gas composition, being detected by means of an exhaust-gas probe () and the exhaust-gas composition being determined as a function of the actual probe signal by means of a characteristic curve or a calculation rule, and wherein the determined exhaust-gas composition is compared with a setpoint value or a threshold value, the attainment or exceedance of which triggers a manipulation of the air-fuel ratio supplied to the internal combustion engine (), wherein, in order to take into consideration at least one disturbance variable which affects the actual probe signal, a safety margin (&#x394;S) is defined which is applied to the characteristic curve or calculation rule, to the actual probe signal or to the setpoint value or threshold value. It is provided that an evaluation of a present accuracy of the at least one disturbance variable and/or of a present influence of the at least one disturbance variable on the probe signal is performed, and the safety margin (&#x394;S) owing to the at least one disturbance variable is defined as a function of the evaluation.

Method and device for regulating an air-fuel ratio of an internal combustion engine

The invention relates to a method for operating an internal combustion engine. According to the method, an exhaust gas produced by the internal combustion engine is conducted across a 3-way catalytic converter arranged in the exhaust duct. A lambda probe detects a value characteristic of an exhaust-gas lambda number upstream of the 3-way catalytic converter, and transmits said value to an engine control unit with an integrated PI or PID regulator. By means of the PI or PID regulator of the engine control unit, through the specification of a setpoint value, a substantially stoichiometric exhaust-gas lambda number is set, and the exhaust-gas lambda number is, with predefined periodic setpoint value variation, deflected alternately in the direction of a lean lambda number and a rich lambda number (lambda modulation). At the start of each setpoint value variation, a pilot-controlled P component with subsequent I component is predefined up to a time t, wherein the time tis defined by means of stored parameters, which characterize a section time behavior, such that the probe signal or a value derived therefrom would have had to have reached the setpoint value specification at said time t. From the time tonwards, for a predefinable time period until the end of the respective setpoint value variation, a switch is made to a regulating algorithm which is based on a difference between an actual value and the setpoint value of the lambda probe or a value derived therefrom.

Method for operating an internal combustion engine, and control unit set up for carrying out the method

In a method for operating a lambda sensor disposed in an exhaust gas system of an internal combustion engine,&#x2014;the heating element is subjected to a predefined heating power substantially with the start of the engine;&#x2014;during the heating process, the sensor signal is detected and compared to a threshold value specified for a lean and/or rich fuel/air mixture ratio, wherein the threshold value correlates with a sensor temperature, which is below the water ingestion critical temperature, and to a valid lambda signal,&#x2014;when one of the specified threshold values is reached for the first time, a measured variable correlating with the sensor temperature is determined and the lambda signal is set as valid and forwarded, and&#x2014;the determined measured variable correlating with the sensor temperature is transferred to a closed heating element control loop as a target value that corresponds to a target temperature.

Method for operating a lambda sensor during the heating phase

The invention is directed to a method and a system for controlling a drive torque of a hybrid drive unit () of an automobile after a start. The hybrid drive unit () includes a first drive source (), in particular an internal combustion engine, includes at least one electric machine (), which can be operated either in motor-mode or in generator-mode, wherein the electric machine () provides in motor operation an electromotive torque (M_EM), which in conjunction with a torque (M_VM) of the first drive source () represents a total drive torque of the drive unit (), and supplies in generator-mode electric power.

Method and system for torque control of a hybrid automobile after a start

In a method and device for mixture control for an internal combustion engine having at least one catalytic converter disposed in an exhaust system of the internal combustion engine and a &#x3bb;-closed-loop control, a value being ascertained for the loading of the catalytic converter with oxygen and the mixture being changed as a function of the ascertained value, a first mixture change is made in the direction of rich exhaust gas when the ascertained value of the oxygen loading has increased by more than a first predefined measure within a predetermined time span and/or after throughput of a predetermined quantity of exhaust-gas mass; and/or a second mixture change is made in the direction of lean exhaust gas when the ascertained value of the oxygen loading has dropped by more than a second predefined measure within a predetermined time span and/or after throughput of a predetermined quantity of exhaust-gas mass.

Expanded mixture control for reducing exhaust-gas emissions

In a method for the lambda control in an internal combustion engine with at least one catalytic converter, with the exhaust system being provided with front and rear lambda control circuits lambda with at least one rear oxygen sensor downstream in reference to the catalytic converter, with an output signal of the rear oxygen sensor being processed by the rear lambda control circuit, a difference value being formed to a rear target lambda value, and an actuating variable being formed acting on the target lambda value of the front lambda control circuit it is provided that after a change of the algebraic sign of the difference value a balanced oxygen amount is determined for a time interval since the sign change from the oxygen amount entered into and removed from the catalytic converter and the actuating variable of the rear lambda control circuit being selected depending on the balanced oxygen amount.

Lambda controller with balancing of the quantity of oxygen

The invention relates to a device and method for determining the need for regeneration in a NOstorage catalyst () arranged in the exhaust train () of an at least periodically lean-operating internal combustion engine () for a motor vehicle. According to the invention, the need for regeneration is determined according to the engine power (P) of the internal combustion engine () and the remaining NOstorage capacity of the NOstorage catalyst.

[object Object]

A method for the desulfurization of an NOstorage catalyst arranged in an exhaust system of an internal combustion engine, whereby, for the desulfurization, the internal combustion engine is alternatingly operated in a lean mode at &#x3bb;&#x3e;1 and a rich mode at &#x3bb;&#x3c;1. During the desulfurization process, the present invention provides for the progress of the desulfurization being monitored, using a change in a parameter relating to intervals (I), whereby the interval (I) lasts from the beginning of an nrich operating phase (T), until the measured value drops below a predetermined lambda threshold value (S) downstream from the NOstorage catalyst (). Furthermore, the progress of the desulfurization is monitored, using a change in a lambda probe voltage (U) downstream from the NOstorage catalyst (), which is determined at the end of a predetermined interval at the beginning of an nrich operating phase (T).

Method for desulfurization of an NOx storage accumulator-catalyst arranged in an exhaust system of an internal combustion engine

The invention relates to a method and device for controlling the NOregeneration of a NOstorage catalyst () disposed in the exhaust gas train () of an internal combustion engine () of a motor vehicle. The NOregeneration is at least initiated when a threshold value is exceeded for a load state of a NOstorage catalyst () or a NOemission downstream from the NOstorage catalyst (). According to the invention, it is detected (a) whether the internal combustion engine () is idling and (b) alternately or in any possible combination, the threshold value for the load state or the NOemission is increased; the NOregeneration is only initiated after a specific amount of time has elapsed and a current NOregeneration is interrupted when a shift occurs into an idling mode.

Device and method for controlling the nox regeneration of a nox storage catalyst

The invention relates to a method for monitoring the functioning of an NOx sensor, which is arranged in an exhaust gas channel of an internal combustion engine and is located downstream from an NOx storage catalytic converter. The aim of the invention is to detect the faulty functioning of the NOx sensor in a simple manner in order to be able to take appropriate measures if necessary. To this end, the mass of NOx absorbed by the NOx storage catalytic converter is determined within a diagnostic period using a measurement signal of the NOx sensor. At the same time, an absorbed NOx target mass is calculated using a model for the NOx storage catalytic converter. A ratio of the NOx mass to the NOx target mass is then compared to predetermined limit values to determine the functioning of the NOx sensor. The aim of the invention is alternatively accomplished by measuring a duration time for a complete NOx regeneration of the NOx storage catalytic converter. A specified duration time is also calculated for the NOx regeneration using a model for the NOx storage catalytic converter and using a measured or calculated NOx load state. A ratio of the measured duration time to the specified duration time is then compared to predetermined limit values to determine the functioning of the NOx sensor.

Method for monitoring the functioning of a NOx sensor arranged in an exhaust gas channel of an internal combustion engine

The invention relates to a method for controlling a NO storage catalyst by means of a NO -sensitive measuring device, especially a NO sensor, that is arranged downstream in relation to the NO storage catalyst which is arranged in an exhaust gas channel of a combustion engine. According to the invention, a reference time (t ) is determined by means of a signal path of the NO -sensitive measuring device ( ) after the combustion engine ( ) has been switched into a lean operating mode. Said reference time is used as the timely starting point for controlling processes being related to the NO storage catalyst ( ). The invention also relates to a device for carrying out the method. According to said device, means are provided by means of which the following procedure steps can be carried out: determining a reference time (t ) by means of a signal path (SV) of the NO -sensitive measuring device ( ) after regeneration of the NO storage catalyst ( ) and using the reference time (t ) as the timely starting point for controlling processes of the NO storage catalyst ( ).

Method and device for controlling a NOx storage catalyst that is arranged in an exhaust gas channel of a combustion engine

The end of a regeneration interval of an NOx accumulating catalytic converter for an engine run on a lean mixture is determined by detecting the end of the regeneration phase of the NOx accumulator using a sensor having a cross-sensitivity NOx and to a reducing agent in an exhaust-gas constituent which passes through the catalytic converter at the end of the regeneration phase. Exhaust-gas reducing constituents such as CO and NH , which can be detected by a cross-sensitive NOx sensor, can be the exhaust-gas products detected at the end of the regeneration phase. By determining the end and beginning of a regeneration phase, different control functions and various types of information can be deduced, including control of the completion of rich-mixture engine operations, correction of a stored regeneration model in the engine management system, and ageing of the catalytic converter.

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Hannover, Germany

Hermann Hahn