Method of determining the evaluation time for a diagnosis

A system comprising:

• at least one sensor configured to measure exhaust gas values;
• and a computer connected to the sensor and configured to
• determine a suitable evaluation time for a diagnosis method for the diagnosis of an SCR catalyst, wherein the diagnosis method is based on at least one sensor value measured via the at least one sensor and in relation to the SCR catalyst and at least one modeled comparative value (cOBDsim), wherein the diagnosis method and the method of determining a suitable evaluation time in the diagnosis method are executed in parallel,
• replace, in the diagnosis method, at least one measured sensor value with a calculated model value (cBPU), where the model (20) for the calculation of the model value is a model of the SCR catalyst in a state that is to be recognized by the diagnosis method;
• execute (102, 104, 106) the diagnosis method with the calculated model value;
• obtain a result value (aOBDsim) of the diagnosis method;
• repeating the preceding steps until the result value attains a defined threshold value;
• and
• fix the suitable evaluation time in the diagnosis method as the time at which the result value has attained the threshold value, and triggering the evaluation of the diagnosis method at the fixed evaluation time.

A non-transitory, computer-readable medium containing instructions that when executed on a computer cause the computer to

• determine a suitable evaluation time for a diagnosis method for the diagnosis of an SCR catalyst, wherein the diagnosis method is based on at least one sensor value, measured via at least one sensor configured to measure exhaust gas values, and in relation to the SCR catalyst and at least one modeled comparative value (cOBDsim), wherein the diagnosis method and the method of determining a suitable evaluation time in the diagnosis method are executed in parallel,
• replace, in the diagnosis method, at least one measured sensor value with a calculated model value (cBPU), where the model (20) for the calculation of the model value is a model of the SCR catalyst in a state that is to be recognized by the diagnosis method;
• execute (102, 104, 106) the diagnosis method with the calculated model value;
• obtain a result value (aOBDsim) of the diagnosis method;
• repeating the preceding steps until the result value attains a defined threshold value;
• and
• fix the suitable evaluation time in the diagnosis method as the time at which the result value has attained the threshold value, and triggering the evaluation of the diagnosis method at the fixed evaluation time.