Efficient filter cleaning

A method for operating a vacuum cleaning appliance having a filter, a filter element cleaner, a controller, a turbine for sucking in an air stream through the filter, a first pressure sensor and a second pressure sensor, wherein the first pressure sensor, for determining a first pressure value, is positioned upstream of the filter in a flow direction, and the second pressure sensor, for determining a second pressure value, is positioned downstream of the filter in the flow direction, the method comprising steps of:

• operating the vacuum cleaning appliance to suck in the air stream through the filter;
• measuring a pressure difference between the first and second pressure values and determining a first pressure reference value according to a relationship of the first pressure value to the second pressure value;
• further operating the vacuum cleaning appliance while monitoring the first pressure value and the second pressure value continuously or at regular intervals;
• dedusting in a dedusting phase the filter with the aid of the filter element cleaner when a pressure difference value of the pressure difference between the first and second pressure values reaches a first predetermined threshold value, the first predetermined threshold value being higher than the first pressure reference value;
• determining after the dedusting phase a second pressure reference value according to a relationship of the first pressure value to the second pressure value;
• and determining that a difference between the second pressure reference value and the first pressure reference value is at or below a second predetermined threshold value, and continuing operating the vacuum cleaning appliance again while monitoring the first pressure value and the second pressure value continuously or at regular intervals and again dedusting the filter in a subsequent dedusting phase when the pressure difference value of the pressure difference between the first and second pressure values reaches the first predetermined threshold value;
• determining that a difference between the second pressure reference value and the first pressure reference value is above the second predetermined threshold value and further dedusting the filter with the aid of the filter element cleaner as an additional dedusting in the dedusting phase;
• determining a third pressure reference value according to a relationship of the first pressure value to the second pressure value after the further dedusting and determining that the third reference value is equal to or less than the second predetermined threshold value and continuing operating the vacuum cleaning appliance yet again while monitoring the first pressure value and the second pressure value continuously or at regular intervals and yet again dedusting the filter in a second subsequent dedusting phase when the pressure difference value of the pressure difference between the first and second pressure values reaches the first predetermined threshold value.