# US 2009/0260429 A1 · Procedure and device for diagnosing the dynamic of an exhaust gas sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2009/0260429 A1 - Document ID: US20090260429A1 - Status: Published application - Kind: A1 - Application number: 12/421,370 - Filed: 2009-04-09 - Published: 2009-10-22 - Earliest claimed: 2008-04-16 - Assignees: Robert Bosch GmbH - Inventors: KERSTEN WEHMEIER; RONALDI RUSLI; ANDREAS KORING; RICHARD HOTZEL - Web page: https://patentgrep.com/patent/US20090260429A1 ## CPC - F02D 41/1495: {Detection of abnormalities in the air/fuel ratio feedback system} - F01N 11/007: {the diagnostic devices measuring oxygen or air concentration downstream of the exhaust apparatus} - F02D 41/1454: {the characteristics being an oxygen content or concentration or the air-fuel ratio} - F01N 2560/025: for measuring or detecting O2, e.g. lambda sensors - F01N 2560/14: having more than one sensor of one kind - F02D 41/008: {Controlling each cylinder individually} - F02D 41/1441: {Plural sensors} - F02D 2041/1432: {the system including a filter, e.g. a low pass or high pass filter} - Y02T 10/40: Engine management systems - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract 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. ## Claims ### Claim 1 A method of diagnosing a dynamic of an exhaust gas sensor that is arranged in an exhaust gas duct of a combustion engine, wherein a regulated control loop controls the exhaust gas sensor to provide a parameter of a gas mixture that is supplied to the combustion engine, the method comprising: in a diagnosing period, using 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 for the diagnosis; and assuming the dynamic of the exhaust gas sensor in an evaluation algorithm. ### Claim 2 (depends on 1) The method of claim 1, further comprising evaluating a temporal change of the regulation correcting variable or of the output signal of the exhaust gas signal for a certain time with regard to achieving very high or very low deflections to diagnose an error of the exhaust gas sensor. ### Claim 3 (depends on 1) The method of claim 1, further comprising, upon implementation of the evaluation algorithm, detecting time periods with a minimum length, a cycling of maximum values, and cycling of minimum values for the regulation correcting variable or for the output signal of the exhaust gas sensor, wherein detected values are each saved in a counter during a release condition. ### Claim 4 (depends on 3) The method of claim 3, further comprising detecting a maximum value or a minimum value of the regulation correction value or of the output signal of the exhaust gas sensor when an upper threshold is exceeded or a lower threshold value is fallen short of. ### Claim 5 (depends on 4) The method of claim 4, further comprising only counting the maximum values or the minimum values of the regulation correcting value or of the output signal of the exhaust gas sensor if the values occur alternately. ### Claim 6 (depends on 4) The method of claim 4, further comprising detecting an erroneous exhaust gas sensor if the counter for the maximum values or the counter for the minimum values reach a certain threshold value before certain counter values are achieved in the counter for detecting time periods with a minimum length ### Claim 7 (depends on 1) The method of claim 1, further comprising creating a product of the regulating correcting variable and another variable that is derived by using a calculation operation from the output signal of the exhaust gas sensor, wherein a temporal course of the product is evaluated with regard to exceeding certain threshold values. ### Claim 8 (depends on 7) The method of claim 7, further comprising using a filter function on the temporal course of the product. ### Claim 9 (depends on 7) The method of claim 7, further comprising using a high-pass filter function on the regulation correcting variable before the connection with the other variable. ### Claim 10 (depends on 1) The method of claim 1, wherein the exhaust gas sensor is a two-point lambda probe or a wideband lambda probe, and wherein a temporal course of a lambda value is evaluated as an output signal. ### Claim 11 (depends on 1) The method of claim 1, wherein the exhaust gas sensor is a NOx-sensor, and wherein a temporal course of a NOx-content in the exhaust gas of the combustion engine is evaluated as output signal. ### Claim 12 (depends on 1) The method of claim 1, further comprising, upon detection of an erroneous exhaust gas sensor, performing at least one of: signaling the error to an operator of the combustion engine; and registering the error in an error storage. ### Claim 13 (depends on 1) The method of claim 1, further comprising using a combustion engine with a multi-bank exhaust gas system, wherein exhaust gas of different cylinder groups is delivered in separated exhaust gas ducts, and wherein at least one exhaust gas sensor is built in each exhaust gas duct. ### Claim 14 A device configured to implement a method of diagnosing a dynamic of an exhaust gas sensor that is arranged in an exhaust gas duct of a combustion engine, wherein a regulated control loop controls the exhaust gas sensor to provide a parameter of a gas mixture that is supplied to the combustion engine, the method comprising: in a diagnosing period, using 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 for the diagnosis; and assuming the dynamic of the exhaust gas sensor in an evaluation algorithm.