Method for cleaning a filter of a vacuum cleaning apparatus and vacuum cleaning apparatus therefor

A vacuum cleaning apparatus, comprising:

• a suction inlet;
• a dirt collection container;
• a filter device having at least one filter;
• a suction unit having a fan, wherein the dirt collection container is in flow communication with the suction unit via the filter device;
• a filter cleaning device for the filter device;
• a first pressure sensor which determines a first pressure in an inflow section of the filter device;
• a second pressure sensor which determines a second pressure in an outflow section of the filter device;
• and
• a control device which controls the filter cleaning device and is operatively connected for signal communication with the first pressure sensor and the second pressure sensor;
• wherein a determination device is provided which determines a quantity characterizing a volume flow of suction air at the filter device;
• wherein the control device comprises an evaluation device which determines, from a pressure difference between the first pressure and the second pressure and the quantity characterizing the volume flow, a quantity that characterizes a flow resistance of the filter device;
• and
• wherein the control device comprises a threshold value test device which tests whether the determined quantity that characterizes the flow resistance is above a threshold value and if so, initiates a filter cleaning operation by controlling the filter cleaning device.