Method for providing measured values of a technical installation, technical system, and method for operating the technical system

A method for providing measured values of a technical installation, in which measured values in a plurality of measurement series are captured, wherein a respective measured value is provided by a respective measurement sensor for a respective physical measurement variable in the technical installation for a respective measurement time, and the measured values are categorized as normal measured values or anomalous measured values with the aid of a threshold value comparison and at least one further method stage, comprising:

• carrying out the threshold value comparison as a first method stage with the steps of:
• capturing at least one measured value in at least one measurement series of the plurality of measurement series,
• comparing the at least one measured value with a predefined threshold value in order to generate a comparison result, and
• identifying the at least one measured value as a normal measured value or as a first type of anomalous measured value on the basis of the comparison result, and
• carrying out the at least one further method stage, the at least one further method stage being at least one of a second method stage and a third method stage,
• wherein the second method stage comprises:
• capturing a plurality of selected measured values in the plurality of measurement series, wherein the plurality of selected measured values are provided by different measurement sensors for the same measurement variable and for the same measurement time,
• calculating a statistical position parameter of the selected measured values,
• for at least one of the captured selected measured values:
• comparing the at least one captured selected measured value with the statistical position parameter and, if the at least one captured selected measured value deviates from the statistical position parameter by more than a predefined relative or absolute deviation, identifying the at least one captured selected measured value as a second type of anomalous measured value,
• wherein the third method stage comprises:
• capturing a chronological measurement series having chronological measured values, wherein the chronological measured values are provided by a measurement sensor for the same measurement variable and for different measurement times, and the chronological measured values in the chronological measurement series are arranged chronologically, and
• for at least one of the captured chronological measured values in the chronological measurement series:
• determining a first statistical position parameter and a first statistical dispersion parameter for a first predefined number of chronological measured values in the same chronological measurement series which temporally precede the at least one chronological measured value in the chronological measurement series,
• determining a second statistical position parameter and a second statistical dispersion parameter for a second predefined number of chronological measured values in the same chronological measurement series which temporally succeed the at least one chronological measured value in the chronological measurement series,
• calculating a first quotient from the absolute value of the difference between the at least one measured value and the first statistical position parameter and the first statistical dispersion parameter,
• calculating a second quotient from the absolute value of the difference between the at least one chronological measured value and the second statistical position parameter and the second statistical dispersion parameter,
• identifying the at least one chronological measured value as a third type of anomalous measured value if the first quotient is greater than or equal to a predefined first comparison value and the second quotient is greater than or equal to a predefined second comparison value, or as a normal measured value if the first quotient is less than the predefined first comparison value or the second quotient is less than the predefined second comparison value.