Patent application number | Description | Published |
20100107728 | PROCEDURE AND DEVICE FOR DETECTING MANIPULATIONS AT LAMBDA PROBES - 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. | 05-06-2010 |
20130199283 | METHOD AND DEVICE FOR DIAGNOSING DEVIATIONS IN A SINGLE CYLINDER LAMBDA CONTROL - 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 said 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 said 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. | 08-08-2013 |
20130263652 | METHOD FOR DETECTING THE OPERATIONAL READINESS OF A JUMP LAMBDA SENSOR - In a method for detecting the operational readiness of a jump lambda sensor associated with an internal combustion engine the internal resistance of the sensor is determined as the criterion for the operational readiness of the sensor. The internal resistance is measured by applying a pulsed current to the sensor, the frequency of the current being selected as a function of the state of the sensor ( | 10-10-2013 |
20130327124 | METHOD FOR SETTING A TEMPERATURE OF A SENSOR ELEMENT - A method for setting a temperature of a sensor element, which is heatable with the aid of a heating device, for detecting at least one property of a gas in a measuring gas chamber includes at least one regulation of the heating device, the regulation including: (a) detecting at least one actual value of at least one controlled variable of the sensor element, (b) ascertaining a setpoint value of the at least one controlled variable, (c) generating at least one manipulated variable of the heating device with the aid of a comparison of the setpoint value and the actual value, and (d) in a monitoring step, checking at least one parameter used to set the temperature, and the at least one manipulated variable being influenced as a function of the check. | 12-12-2013 |
20140007644 | METHOD AND DEVICE FOR CORRECTING A CHARACTERISTIC CURVE OF A TWO-STEP LAMBDA OXYGEN SENSOR - A method and device for correcting a voltage-lambda characteristic curve of a two-step lambda oxygen sensor in an exhaust tract relative to a reference-voltage lambda characteristic curve of the oxygen sensor; a deviation in the characteristic curve relative to the reference characteristic curve at lambda=1 being corrected; based on a value pair on the reference-voltage lambda characteristic curve, the composition of the air-fuel mixture supplied to the engine being changed toward lambda=1; the actual value of lambda being inferred from the change in the composition of the air-fuel mixture. The adaptation of the operating parameters of the oxygen sensor is intended to eliminate the cause of a deviation. Efforts are not merely directed to adapting the deviation to the reference characteristic curve by shifting the voltage-lambda characteristic curve. Effects, which may lead to tolerance- or aging-induced falsifications of the voltage-lambda characteristic curve, can be fully compensated. | 01-09-2014 |
20140007651 | METHOD AND DEVICE FOR DETERMINING A LAMBDA AIR RATIO USING A GAS SENSOR - A method for determining a lambda air ratio using a gas sensor having a ceramic measuring element, an output voltage of the gas sensor changing abruptly if lambda is changed in the range around lambda=1 and the gas sensor having an initial inverse voltage which is dependent on the temperature of the gas sensor. A threshold value for the initial inverse voltage is established for a limit between a lambda value below and above 1 as a function of the temperature of the gas sensor. Also described is a device for implementing the method. The method and the device make it possible to operate gas sensors having a ceramic measuring element at an even lower temperature than according to the related art and thus reduce the period between the start of an internal combustion engine and the operational readiness of a lambda regulation. This makes it possible to reduce the fuel consumption as well as the emission of undesirable components of the exhaust gas. | 01-09-2014 |
20140012486 | Method and control unit for detecting a voltage offset of a voltage-lambda characteristic curve - A method/control unit for detecting a voltage offset in a range of a voltage-lambda characteristic curve of a two-point lambda sensor in an engine exhaust gas duct as to a reference voltage-lambda characteristic curve of the two-point lambda sensor, which is part of a controlled system for adjusting an air-fuel mixture supplied to the engine, a characteristic curve deviation of voltage-lambda characteristic curve to the reference characteristic curve being corrected at λ=1, so that a change in the air-fuel mixture composition toward λ=1 occurs, starting from a value pair to be checked on the reference characteristic curve, with a lambda and a voltage to be checked, the actual value of lambda being inferred from the change in the mixture composition until reaching λ=1. The method/control unit permit determining and compensating a voltage offset of a two-point lambda sensor conditional upon aging or manufacturing tolerances. | 01-09-2014 |
20150135802 | METHOD AND CONTROL UNIT FOR COMPENSATING FOR A VOLTAGE OFFSET OF A TWO-POINT LAMBDA SENSOR - A method is described for compensating for a voltage offset in a voltage-lambda characteristic curve of a two-point lambda sensor in relation to a reference voltage-lambda characteristic curve of the two-point lambda sensor, the two-point lambda sensor being situated in an exhaust duct of an internal combustion engine. It is provided that the slope of the voltage-lambda characteristic curve is determined for an output voltage of the two-point lambda sensor and is compared to the slope of a reference voltage-lambda characteristic curve at equal output voltage, and the voltage offset is determined from a deviation of the determined slope of the voltage-lambda characteristic curve from the slope of the reference voltage-lambda characteristic curve. Also described is a control unit for carrying out the method. The method and the control unit enable the determination of and compensation for a voltage offset of a two-point lambda sensor caused by aging or manufacturing tolerances. | 05-21-2015 |