Robert Boschgmbh

Andreas Koring

Eberhard Schnaibel

Klaus Winkler

Holger Bellmann

Andreas Blumenstock

Kersten Wehmeier

Bernd Schumann

Michael Fey

Thomas Wahl

Frank Stanglmeier

Richard Hotzel

Ruediger Deibert

Beate Rittmann

Ronaldi Rusli

Lothar Diehl

Erich Schneider

Erich Junginger

Andreas Roth

Jens Wagner

Michael Daetz

Richard Holberg

Harry Braun

Matthias Kuentzle

Ralf Daeubel

Oliver Schlesiger

Lu Chen

Martin Sternke

The invention relates to a method and device for diagnosing deviations in a single cylinder lambda control in an internal combustion engine having at least two cylinders and an exhaust gas sensor designed as a broadband lambda sensor, wherein a pump current is evaluated by means of a pump cell and the pump current is used at least temporarily for an individual cylinder lambda control. According to the invention, a pump voltage or a pump voltage change is determined via the pump cell in addition to the pump current and the value is transmitted to a diagnosis apparatus. Deviations in the single cylinder lambda control can thus be better diagnosed without additional material expense according to the invention, which provides advantages in particular in respect of tightened rulemaking in on-board diagnosis. A preferred application of the method is the use in internal combustion engines having multi-bank exhaust systems.

Method and device for diagnosing deviations in a single cylinder lambda control

A method for diagnosing and/or adapting at least one system () of a device () is described, which method comprises the following steps:

Method for diagnosing and/or adapting at least one system of a device

A procedure for detecting manipulations at lambda comprises the following steps; the lambda probe is excited by at least one electric excitation signal; at least one electric response signal of the probe is detected; the at least one response signal is compared to at least one default electric response signal that characterizes a not manipulated probe; the deviation of the detected at least one electric response signal from the at least one default electric response signal is used for detecting a manipulation of the probe. A device for detecting manipulations at lambda probes characterized by a switch assembly, with which the probe can be impinged with an electric excitation signal, in particular a step-wise electric excitation, preferably with a current impulse, by a evaluation switch device for evaluating a response signal, in particular the probe voltage and for comparing the excitation signal with the response signal and for assuming a manipulation in the case of a deviation of the response signal from a response signal that characterizes a not manipulated probe.

Procedure and device for detecting manipulations at lambda probes

A procedure and device for diagnosing the increasing speed and the dead time of an exhaust gas probe includes carrying out the diagnosis by comparing a modeled and a measured signal after a default change of a fuel air ratio of an air fuel mixture that is supplied to a combustion engine. The signal is an output signal of the exhaust gas probe or a modeled or measured signal that is derived from the output signal. The device for diagnosing the velocity and the dead time of an exhaust gas probe also includes a comparing unit for comparing the modeled signal with the measured signal for diagnosing the velocity and the dead time of the exhaust gas probe after a default change of a fuel air ratio of an air fuel mixture that is supplied to the combustion engine.

Procedure and device for diagnosing an exhaust gas probe

The invention concerns a procedure and a device for diagnosing the dynamic of an exhaust gas sensor, which is arranged in an exhaust gas duct of a combustion engine and with which a parameter of the gas mixture that is supplied to the combustion engine is regulated by a control loop. It is thereby provided according to the invention that during a diagnosing period a temporal deflection of a regulation correcting variable for the parameter that is derived from an output signal of the exhaust gas sensor or a temporal course of the output signal of the exhaust gas sensor is used for the diagnosis and that the dynamic of the exhaust gas sensor is assumed in an evaluation algorithm. Thereby an improvement of the on-board diagnosis of the dynamic of the exhaust gas sensor can be achieved and in particular lambda probes, which provide a slowing down of their responding behavior, can be detected early on.

Procedure and device for diagnosing the dynamic of an exhaust gas sensor

A method for diagnosing the dynamic characteristics of a lambda sensor, which is used at least intermittently for a cylinder-individual lambda closed-loop control, which provides for at least one actuating variable of the lambda closed-loop control to be detected and compared to a specifiable maximum threshold, and, if the maximum threshold is exceeded, the dynamic response of the lambda sensor is deemed insufficient with respect to the usability for the cylinder-individual lambda closed-loop control.

Method and device for diagnosing the dynamic characteristics of a lambda probe used for the lambda regulation of individual cylinders

A circuit configuration for operating a gas sensor is described, including a reference gas space in which an electrode is situated which is supplied with a reference gas pump current to maintain the concentration of the reference gas. A diagnostic system determines a concentration change of the reference gas via a change in the reference pump current and a time-based evaluation of the sensor signal of the gas sensor.

Circuit arrangement for operating a gas sensor

A method for controlling and regulating an electrical heating of a probe situated in the exhaust system of an internal combustion engine, a total heating power of the probe being set, and an actual temperature value of the probe being determined by measuring a characteristic parameter, e.g., a resistance. To prevent overheating of the probe ceramics, and therefore over-compensation of aging effects when using such a method, a rated heating power is determined by way of a program map as a function of operating points of the internal combustion engine; a control heating power is determined from the actual temperature value and a new setpoint value in a controller; and the total heating power is formed as the sum of the rated heating power and the control heating power. Moreover, due to this procedure, the regulating reserve of the controller is retained in wide ranges of the operating points. A cost advantage is yielded, because a measuring resistor and an analog-to-digital converter can be omitted. Also, a device for controlling and regulating an electrical heating of a probe situated in the exhaust system of an internal combustion engine, for implementing the method. Because a program map and a controller are connected via a summing stage, a particularly simply constructed device is provided which prevents overheating of the exhaust gas analyzer probe.

Method and device for control and diagnosis for the heating of a lambda probe

A method for influencing the exhaust gas temperature of an internal combustion engine is described in which measures can be carried out for increasing, lowering and limiting exhaust gas temperature. Depending on temperature requirements, and in which method these temperature requirements are prioritized, the temperature limitation having the highest priority for ensuring protection of the component parts, the resulting temperature requirement may be achieved by heating measures or cooling measures in such a way that heating measures and cooling measures are not applied at the same time.

Co-ordination of different requirements of the exhaust gas temperature and corresponding heating and cooling measures

An internal combustion engine, in particular for a motor vehicle, in which fuel may be injected into a combustion chamber during an intake phase in a first mode of operation or during a compression phase in a second mode of operation, and in which exhaust gases may be sent to a catalytic converter. A control unit determines a temperature difference between an actual exhaust gas temperature and a setpoint exhaust gas temperature at an operating point having a low exhaust gas temperature. In addition, at least one additional injection after combustion is implemented by the control unit as a function of the temperature difference.

Method of operating an internal combustion engine

An internal combustion engine for a motor vehicle. In the internal combustion engine, fuel is injected directly into a combustion chamber and is burned during an intake phase in a first mode of operation and during a compression phase in a second mode of operation. Exhaust gas formed by combustion may be sent to a catalytic converter. A controller may cause additional fuel to be injected following combustion in the second mode of operation. The controller may also cause the temperature of the exhaust gas to be measured in or downstream from the catalytic converter and compared with a threshold value.

Method for operating an internal combustion engine, in particular, of a motor vehicle

An internal combustion engine, especially for a motor vehicle, is described, which is provided with a catalytic converter which can be charged with hydrocarbons. The converting capability of the catalytic converter can be determined by a control apparatus. The converting capability of the catalytic converter is determined by the control apparatus by means of a combination of a passive and an active diagnostic method ( ).

Method for operating and internal combustion engine, in particular of a motor vehicle

An internal combustion engine, especially for a motor vehicle, is described, which is provided with a storage catalytic converter which can be loaded with and unloaded of nitrogen oxides. Several states of deterioration (points ) of the storage catalytic converter can be determined by the control apparatus. A sulphur content of the fuel used can be determined by the control apparatus from sequential states of deterioration (points ).

Method for operating an accumulator-type catalytic converter of an internal combustion engine

An internal combustion engine ( ), especially for a motor vehicle, is described, which has a three-way catalytic converter ( ) and a storage catalytic converter ( ) which can be loaded with and unloaded of nitrogen oxides. A diagnosis of the storage catalytic converter ( ) is carried out by a control apparatus ( ) below a temperature at which the three-way catalytic converter ( ) does not yet operate.

Method for operating a three-way catalyst of an internal combustion engine

An internal combustion engine ( ), especially for a motor vehicle, is described, which has a catalytic converter ( ) which can be loaded with and unloaded of nitrogen oxides. An NOx sensor ( ) is provided with which NOx emissions can be measured downstream of the catalytic converter ( ). The catalytic converter ( ) can be only partially loaded by a control apparatus ( ). An increased NOx emission can be generated forward of or in the catalytic converter ( ) by the control apparatus ( ). A conclusion can be drawn as to the operability of the catalytic converter ( ) by the control apparatus ( ) from NOx emissions measured downstream.

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Reutlingen, Germany

Andreas Koring