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Time Series Amplitude

Overview

The FeatureCalcTimeseriesAmplitude class is a subclass of FeatureCalculator that calculates the amplitude of the time series of a vibration signal. This allows for creating features that show the trend in time of the amplitude of a signal, enabling us to quickly check tendencies associated with vibration and blade gap data.

Calculation Logic

The calculation logic is described in the constructor of the class, shown below in the Class Definition section.

Database Requirements

  • Feature attribute server_calc_type must be set to timeseries_amplitude.
  • Feature attribute feature_options_json with the following keys:.
    • sensor_name: Name of the sensor that will be used to get the timeseries. Names must be the ones available for perfdb.vibration.timeseries.get method.
    • data_type: Type of the data that will be used to get the timeseries. All values allowed in perfdb.vibration.timeseries.get method are valid. For example, "Vibration", etc.
    • acquisition_rate: Acquisition rate of the sensor. Only applicable for Gamesa turbines and vibration sensors. For other manufacturers set this to none.
    • variable_name: Name of the variable that will be used to get the timeseries. This is only applicable for Gamesa turbines and blade gap sensors (deprecated). For other manufacturers set this to none.
    • operation: Which time of amplitude calculation will be used. Valid values are "peak", "peak-to-peak", "rms", "mean", "median", "std".
  • Data in raw_data_values table that corresponds to the desired object, sensor, acquisition rate, variable_name and time range.

Below there is an example of the queries needed to create a feature that uses the FeatureCalcTimeseriesAmplitude class:

-- Create the feature
SELECT * FROM performance.fn_create_or_update_feature(
    'G97-2.07', -- name of the object model
    'server_calc', -- name of the data source type (server_calc)
    'test_timeseries_amplitude', -- name of the feature
    'Test for FeatureCalcTimeseriesAmplitude', -- description of the feature
    NULL, -- name of the feature in the data source (not applicable for calculations)
    NULL, -- id of the feature in the data source (not applicable for calculations)
    NULL, -- unit of the feature
    NULL -- leave as NULL, deprecated
);

-- Set the feature attribute `server_calc_type`
SELECT * FROM performance.fn_set_feature_attribute(
    'test_timeseries_amplitude', -- name of the feature
    'G97-2.07', -- name of the object model
    'server_calc_type', -- name of the attribute
    '{"attribute_value": "timeseries_amplitude"}' -- value of the attribute
);

-- Set the feature attribute `feature_options_json`
SELECT * FROM performance.fn_set_feature_attribute(
    'test_timeseries_amplitude', -- name of the feature
    'G97-2.07', -- name of the object model
    'feature_options_json', -- name of the attribute
    '{"attribute_value": {"sensor_name": "Blade C", "data_type": "Blade Gap", "acquisition_rate": null, "variable_name": "Position - Y", "operation": "peak-to-peak"}}' -- value of the attribute
);

Class Definition

FeatureCalcTimeseriesAmplitude(object_name, feature)

FeatureCalculator class for features that are based on the amplitude of the vibration time series of a wind turbine.

The calculation is fairly simple:

  1. Get the vibration timeseries for the specified sensor, data type, acquisition rate, and variable name.
  2. Apply the desired operation (peak, peak-to-peak, rms, mean, median, std) to the timeseries data. This will reduce the timeseries to a single value for each timestamp.

For this to work the feature must have attribute feature_options_json with the following keys:

  • sensor_name: Name of the sensor that will be used to get the timeseries. Names must be the ones available for perfdb.vibration.timeseries.get method.
  • data_type: Type of the data that will be used to get the timeseries. All values allowed in perfdb.vibration.timeseries.get method are valid. For example, "Vibration", etc.
  • acquisition_rate: Acquisition rate of the sensor. Only applicable for Gamesa turbines and vibration sensors. For other manufacturers set this to none.
  • variable_name: Name of the variable that will be used to get the timeseries. This is only applicable for Gamesa turbines and blade gap sensors (deprecated). For other manufacturers set this to none.
  • operation: Which time of amplitude calculation will be used. Valid values are "peak", "peak-to-peak", "rms", "mean", "median", "std".

Parameters:

  • object_name

    (str) –

    Name of the object for which the feature is calculated. It must exist in performance_db.

  • feature

    (str) –

    Feature of the object that is calculated. It must exist in performance_db.

Source code in echo_energycalc/feature_calc_timeseries_amplitude.py
def __init__(
    self,
    object_name: str,
    feature: str,
) -> None:
    """
    FeatureCalculator class for features that are based on the amplitude of the vibration time series of a wind turbine.

    The calculation is fairly simple:

    1. Get the vibration timeseries for the specified sensor, data type, acquisition rate, and variable name.
    2. Apply the desired operation (peak, peak-to-peak, rms, mean, median, std) to the timeseries data. This will reduce the timeseries to a single value for each timestamp.

    For this to work the feature must have attribute `feature_options_json` with the following keys:

    - `sensor_name`: Name of the sensor that will be used to get the timeseries. Names must be the ones available for `perfdb.vibration.timeseries.get` method.
    - `data_type`: Type of the data that will be used to get the timeseries. All values allowed in `perfdb.vibration.timeseries.get` method are valid. For example, "Vibration", etc.
    - `acquisition_rate`: Acquisition rate of the sensor. Only applicable for Gamesa turbines and vibration sensors. For other manufacturers set this to none.
    - `variable_name`: Name of the variable that will be used to get the timeseries. This is only applicable for Gamesa turbines and blade gap sensors (deprecated). For other manufacturers set this to none.
    - `operation`: Which time of amplitude calculation will be used. Valid values are "peak", "peak-to-peak", "rms", "mean", "median", "std".

    Parameters
    ----------
    object_name : str
        Name of the object for which the feature is calculated. It must exist in performance_db.
    feature : str
        Feature of the object that is calculated. It must exist in performance_db.
    """
    # initialize parent class
    super().__init__(object_name, feature)

    # requirements for the feature calculator
    self._add_requirement(RequiredFeatureAttributes(self.object, self.feature, ["feature_options_json"]))
    self._get_required_data()

    # validating feature options
    self._validate_feature_options()

feature property

Feature that is calculated. This will be defined in the constructor and cannot be changed.

Returns:

  • str

    Name of the feature that is calculated.

name property

Name of the feature calculator. Is defined in child classes of FeatureCalculator.

This must be equal to the "server_calc_type" attribute of the feature in performance_db.

Returns:

  • str

    Name of the feature calculator.

object property

Object for which the feature is calculated. This will be defined in the constructor and cannot be changed.

Returns:

  • str

    Object name for which the feature is calculated.

requirements property

List of requirements of the feature calculator. Is defined in child classes of FeatureCalculator.

Returns:

  • dict[str, list[CalculationRequirement]]

    Dict of requirements.

    The keys are the names of the classes of the requirements and the values are lists of requirements of that class.

    For example: {"RequiredFeatures": [RequiredFeatures(...), RequiredFeatures(...)], "RequiredObjects": [RequiredObjects(...)]}

result property

Result of the calculation. This is None until the method "calculate" is called.

Returns:

  • Series | DataFrame | None:

    Result of the calculation if the method "calculate" was called. None otherwise.

calculate(period, save_into=None, cached_data=None, **kwargs)

Method that will calculate the amplitude of a certain frequency band in the vibration spectrum of a wind turbine.

Parameters:

  • period

    (DateTimeRange) –

    Period for which the feature will be calculated.

  • save_into

    (Literal['all', 'performance_db'] | None, default: None ) –

    Argument that will be passed to the method "save". The options are: - "all": The feature will be saved in performance_db and bazefield. - "performance_db": the feature will be saved only in performance_db. - None: The feature will not be saved.

    By default None.

  • cached_data

    (DataFrame | None, default: None ) –

    DataFrame with features already queried/calculated. This is useful to avoid needing to query all the data again from performance_db, making chained calculations a lot more efficient. By default None

  • **kwargs

    (dict, default: {} ) –

    Additional arguments that will be passed to the "_save" method.

Returns:

  • Series

    Pandas Series with the calculated feature.

Source code in echo_energycalc/feature_calc_timeseries_amplitude.py
def calculate(
    self,
    period: DateTimeRange,
    save_into: Literal["all", "performance_db"] | None = None,
    cached_data: DataFrame | None = None,
    **kwargs,
) -> Series:
    """
    Method that will calculate the amplitude of a certain frequency band in the vibration spectrum of a wind turbine.

    Parameters
    ----------
    period : DateTimeRange
        Period for which the feature will be calculated.
    save_into : Literal["all", "performance_db"] | None, optional
        Argument that will be passed to the method "save". The options are:
        - "all": The feature will be saved in performance_db and bazefield.
        - "performance_db": the feature will be saved only in performance_db.
        - None: The feature will not be saved.

        By default None.
    cached_data : DataFrame | None, optional
        DataFrame with features already queried/calculated. This is useful to avoid needing to query all the data again from performance_db, making chained calculations a lot more efficient.
        By default None
    **kwargs : dict, optional
        Additional arguments that will be passed to the "_save" method.

    Returns
    -------
    Series
        Pandas Series with the calculated feature.
    """
    # getting required vibration data
    self._get_required_data(period=period, cached_data=cached_data, only_missing=True)

    # getting vibration data
    vibration_df: DataFrame = self._get_requirement_data("RequiredVibrationData").copy()

    # creating series for the result
    result = self._create_empty_result(period=period, result_type="Series")

    # filtering vibration data
    vibration_df = vibration_df[
        (vibration_df["sensor"] == self._feature_options["sensor_name"])
        & (vibration_df["timestamp"].between(period.start, period.end))
        & (vibration_df["object_name"] == self.object)
    ].copy()

    # acquisition frequency
    if self._feature_options["acquisition_rate"] is not None:
        vibration_df = vibration_df[vibration_df["acquisition_frequency"] == self._feature_options["acquisition_rate"]].copy()

    # variable name
    if self._feature_options["variable_name"] is not None:
        vibration_df = vibration_df[vibration_df["acquisition_frequency"] == self._feature_options["variable_name"]].copy()

    # if vibration_df is empty, return empty result
    if vibration_df.empty:
        logger.debug(f"No vibration data found for object {self.object} in period {period}.")

        result = result.dropna()

        return result

    # reindexing vibration_df with the index in result to match 10 min frequency
    vibration_df["timestamp"] = vibration_df["timestamp"].astype("datetime64[s]")
    vibration_df = vibration_df.set_index("timestamp")
    vibration_df = vibration_df.reindex(result.index, method="nearest", tolerance=timedelta(minutes=4, seconds=59))
    vibration_df.index.name = "timestamp"
    vibration_df = vibration_df.reset_index()
    # dropping all NA values
    vibration_df = vibration_df.dropna(subset=["value"])

    # converting value to numpy arrays for faster iteration
    values = vibration_df["value"].values

    # creating empty list to store the results for each timestamp
    # this will later be inserted into the result series
    temp_result = []

    # getting the operation that will be used to aggregate the values in the band
    operation_name = self._feature_options["operation"]

    # iterating over the vibration data
    for i in range(len(values)):
        # getting the timeseries
        # we use [1] as dimension 0 is the time and 1 is the timeseries values
        timeseries: ndarray = values[i][1]

        # making the operation
        match operation_name:
            case "peak":
                # getting the peak value
                op_result = timeseries.max()
            case "peak-to-peak":
                # getting the peak-to-peak value
                op_result = timeseries.max() - timeseries.min()
            case "rms":
                # getting the root mean square value
                op_result = np.sqrt(np.mean(np.square(timeseries)))
            case "mean":
                # getting the mean value
                op_result = np.mean(timeseries)
            case "median":
                # getting the median value
                op_result = np.median(timeseries)
            case "std":
                # getting the standard deviation value
                op_result = np.std(timeseries)
            case _:
                raise ValueError(f"Operation '{operation_name}' is not supported.")

        temp_result.append(op_result)

    # creating a temporary series with the results
    result = Series(temp_result, index=vibration_df["timestamp"], name=result.name, dtype="float64")

    # dropping NA values
    result = result.dropna()

    # adding calculated feature to class result attribute
    self._result = result.copy()

    # saving results
    self.save(save_into=save_into, **kwargs)

    return result

save(save_into=None, **kwargs)

Method to save the calculated feature values in performance_db.

Parameters:

  • save_into

    (Literal['all', 'performance_db'] | None, default: None ) –

    Argument that will be passed to the method "save". The options are: - "all": The feature will be saved in performance_db and bazefield. - "performance_db": the feature will be saved only in performance_db. - None: The feature will not be saved.

    By default None.

  • **kwargs

    (dict, default: {} ) –

    Not being used at the moment. Here only for compatibility.

Source code in echo_energycalc/feature_calc_core.py
def save(
    self,
    save_into: Literal["all", "performance_db"] | None = None,
    **kwargs,  # noqa: ARG002
) -> None:
    """
    Method to save the calculated feature values in performance_db.

    Parameters
    ----------
    save_into : Literal["all", "performance_db"] | None, optional
        Argument that will be passed to the method "save". The options are:
        - "all": The feature will be saved in performance_db and bazefield.
        - "performance_db": the feature will be saved only in performance_db.
        - None: The feature will not be saved.

        By default None.
    **kwargs : dict, optional
        Not being used at the moment. Here only for compatibility.
    """
    # checking arguments
    if not isinstance(save_into, str | type(None)):
        raise TypeError(f"save_into must be a string or None, not {type(save_into)}")
    if isinstance(save_into, str) and save_into not in ["all", "performance_db"]:
        raise ValueError(f"save_into must be 'all', 'performance_db' or None, not {save_into}")

    # checking if calculation was done
    if self.result is None:
        raise ValueError(
            "The calculation was not done. Cannot save the feature calculation results. Please make sure to do something like 'self._result = df[self.feature].copy()' in the method 'calculate' before calling 'self.save()'.",
        )

    if save_into is None:
        return

    if isinstance(save_into, str):
        if save_into not in ["performance_db", "all"]:
            raise ValueError(f"save_into must be 'performance_db' or 'all', not {save_into}.")
        upload_to_bazefield = save_into == "all"
    elif save_into is None:
        upload_to_bazefield = False
    else:
        raise TypeError(f"save_into must be a string or None, not {type(save_into)}.")

    # converting result series to DataFrame if needed
    if isinstance(self.result, Series):
        result_df = self.result.to_frame()
    elif isinstance(self.result, DataFrame):
        result_df = self.result.droplevel(0, axis=1)
    else:
        raise TypeError(f"result must be a pandas Series or DataFrame, not {type(self.result)}.")

    # adjusting DataFrame to be inserted in the database
    # making the columns a Multindex with levels object_name and feature_name
    result_df.columns = MultiIndex.from_product([[self.object], result_df.columns], names=["object_name", "feature_name"])

    self._perfdb.features.values.series.insert(
        df=result_df,
        on_conflict="update",
        bazefield_upload=upload_to_bazefield,
    )