Method for operating an internal combustion engine

Abstract

A method for operating an internal combustion engine includes the step of measuring emission values of at least two pollutant components of an exhaust gas of an internal combustion engine. A value of at least one operating parameter of the internal combustion engine is changed in order to decrease an emission value of a first pollutant component if the emission value of the first pollutant component exceeds a given maximum threshold value. An emission value of a second pollutant component is monitored in order to determine whether the emission value of the second pollutant component remains below a maximum value for the second pollutant component and whether an increase in the emission value to the maximum value for the second pollutant component is permitted.

1 . A method for operating an internal combustion engine, the method which comprises: 
 providing a lambda probe in an exhaust gas system of an internal combustion engine for continuously regulating a lambda value of an exhaust gas; and    calibrating the lambda probe by using emission values of at least two pollutant components of the exhaust gas.    
   
   
       2 . The method according to  claim 1 , which comprises using a broadband lambda probe as the lambda probe.  
   
   
       3 . The method according to  claim 1 , which comprises using at least two compounds selected from the group consisting of nitrogen oxide, hydrocarbon and carbon monoxide as the at least two pollutant components.  
   
   
       4 . The method according to  claim 1 , which comprises: 
 providing a catalytic converter device in the exhaust gas system; and    calibrating the lambda probe as a function of an operating state of the catalytic converter device.    
   
   
       5 . The method according to  claim 1 , which comprises: 
 providing a catalytic converter device in the exhaust gas system and providing the lambda probe downstream of the catalytic converter device; and    calibrating the lambda probe as a function of an operating state of the catalytic converter device.    
   
   
       6 . The method according to  claim 1 , which comprises: 
 providing a catalytic converter device in the exhaust gas system; and    calibrating the lambda probe only if the catalytic converter device has an operating temperature in a given window.    
   
   
       7 . The method according to  claim 1 , which comprises: 
 preregulating an air/fuel ratio designated as lambda by using a signal of the lambda probe such that a setpoint value of lambda is substantially equal to one;    concluding that an actual value of lambda is greater than one when a nitrogen oxide breakthrough occurs and concluding that an actual value of lambda is less than one when at least one of a hydrocarbon breakthrough and a carbon monoxide breakthrough occurs; and    shifting the air/fuel ratio lambda until the nitrogen oxide breakthrough reaches a minimum and at the same time at least one of the hydrocarbon breakthrough and the carbon monoxide breakthrough reach a minimum.    
   
   
       8 . The method according to  claim 1 , which comprises providing a catalytic converter device including a catalytic converter selected from the group consisting of a three-way catalytic converter, an oxidation catalytic converter, and a NO x  storage catalytic converter.  
   
   
       9 . The method according to  claim 1 , which comprises providing a plurality of exhaust gas paths in an exhaust gas system of the internal combustion engine.  
   
   
       10 . The method according to  claim 1 , which comprises: 
 providing a plurality of exhaust gas paths in an exhaust gas system of the internal combustion engine; and    separately determining emission values assigned to respective ones of the exhaust gas paths.    
   
   
       11 . The method according to  claim 1 , which comprises determining accumulated emission values of at least two pollutant components.  
   
   
       12 . The method according to  claim 1 , which comprises using at least one electrochemical sensor in order to determine the emission values of the at least two pollutant components.  
   
   
       13 . The method according to  claim 1 , which comprises using at least one optical sensor in order to determine the emission values of the at least two pollutant components.  
   
   
       14 . The method according to  claim 1 , which comprises using at least one optical sensor operating according to a principle of reflection spectroscopy in order to determine the emission values of the at least two pollutant components.  
   
   
       15 . The method according to  claim 1 , which comprises using at least one optical sensor operating in an infrared light range in order to determine the emission values of the at least two pollutant components.  
   
   
       16 . The method according to  claim 1 , which comprises using at least one sensor having at least one property selected from the group consisting of a measuring time of less than 500 microseconds and measuring intervals of less than 200 microseconds in order to determine the emission values of the at least two pollutant components.  
   
   
       17 . The method according to  claim 1 , which comprises using at least one sensor to determine both, the emission values of the at least two pollutant components and the lambda value of the exhaust gas.  
   
   
       18 . A method for operating an internal combustion engine, the method which comprises: 
 determining emission values of at least two pollutant components of an exhaust gas of an internal combustion engine;    comparing the emission values of the at least two pollutant components with given setpoint values for providing a comparison result;    using the comparison result in order to form a state signal characteristic of an operating state of the internal combustion engine; and    performing a diagnosis of the operating state of the internal combustion engine.    
   
   
       19 . The method according to  claim 18 , which comprises: 
 changing a value of at least one operating parameter as a function of the comparison result in order to change an emission value of a first one of the at least two pollutant components; and    forming the state signal characteristic of the operating state of the internal combustion engine by using at least one value selected from the group consisting of a required value of a change in the at least one operating parameter and a value of a change in a second one of the at least two pollutant components.    
   
   
       20 . The method according to  claim 18 , which comprises performing the diagnosis by determining an ignition behavior as the operating state of the internal combustion engine.  
   
   
       21 . The method according to  claim 18 , which comprises performing the diagnosis by determining at least one event selected from the group consisting of a misfiring, a delayed combustion and a failed ignition.  
   
   
       22 . The method according to  claim 18 , which comprises: 
 determining at least one parameter selected from the group consisting of a rotational speed of the internal combustion engine and a change in the rotational speed of the internal combustion engine; and    using the at least one parameter for the diagnosis of the operating state of the internal combustion engine.    
   
   
       23 . The method according to  claim 18 , which comprises: 
 determining at least one characteristic selected from the group consisting of a peak height and an envelope-curve shape of the emission values of the at least two pollutant components; and    evaluating the at least one characteristic for the diagnosis of the operating state of the internal combustion engine.    
   
   
       24 . The method according to  claim 18 , which comprises using raw emission values as the emission values.  
   
   
       25 . The method according to  claim 18 , which comprises: 
 providing the internal combustion engine with cylinder banks and associated exhaust gas manifolds; and    performing the diagnosis separately for each of the cylinder banks or each of the associated exhaust gas manifolds.    
   
   
       26 . The method according to  claim 18 , which comprises performing at least one operation selected from the group consisting of displaying a value of the state signal and storing the value of the state signal as a function of the value of the state signal.  
   
   
       27 . The method according to  claim 18 , which comprises providing a catalytic converter device including a catalytic converter selected from the group consisting of a three-way catalytic converter, an oxidation catalytic converter, and a NO x  storage catalytic converter.  
   
   
       28 . The method according to  claim 18 , which comprises providing a plurality of exhaust gas paths in an exhaust gas system of the internal combustion engine.  
   
   
       29 . The method according to  claim 18 , which comprises: 
 providing a plurality of exhaust gas paths in an exhaust gas system of the internal combustion engine; and    separately determining emission values assigned to respective ones of the exhaust gas paths.    
   
   
       30 . The method according to  claim 18 , which comprises determining accumulated emission values of at least two pollutant components.  
   
   
       31 . The method according to  claim 18 , which comprises using at least one electrochemical sensor in order to determine the emission values of the at least two pollutant components.  
   
   
       32 . The method according to  claim 18 , which comprises using at least one optical sensor in order to determine the emission values of the at least two pollutant components.  
   
   
       33 . The method according to  claim 18 , which comprises using at least one optical sensor operating according to a principle of reflection spectroscopy in order to determine the emission values of the at least two pollutant components.  
   
   
       34 . The method according to  claim 18;  which comprises using at least one optical sensor operating in an infrared light range in order to determine the emission values of the at least two pollutant components.  
   
   
       35 . The method according to  claim 18 , which comprises using at least one sensor having at least one property selected from the group consisting of a measuring time of less than 500 microseconds and measuring intervals of less than 200 microseconds in order to determine the emission values of the at least two pollutant components.  
   
   
       36 . The method according to  claim 18 , which comprises using at least one sensor to determine the emission values of the at least two pollutant components and a lambda value of the exhaust gas.