Unbalance control system for vertical-rotation-axis washing machines

摘要

There is described a control system (15) for controlling unbalance of the wash assembly (5) for a vertical-rotation-axis washing machine (1), wherein a wash assembly (5) is housed inside a casing (2), and has a wash drum (8) rotating about an axis of rotation (R) substantially parallel to a vertical reference axis (V), and an electric drive unit (12) for rotating the wash drum (8) about the relative axis of rotation (R); said control system has first computing blocks (19,20,21) for determining a number of operating quantities (Cm(t),J,±(t)) associated with rotation of the wash drum (8), and for determining, as a function of the quantities, the time pattern of the amplitude (h(t)) of vertical oscillation of the centre of mass (B) of the wash assembly (5) in a first direction substantially parallel to the vertical reference axis (V); and a second computing block (23) for determining the maximum amplitude (H) of vertical oscillation of the wash assembly (5) within a given time interval (T); the second computing block (23) also determines whether the maximum amplitude (H) of vertical oscillation satisfies a predetermined relationship with a predetermined threshold (SA), and determines a critical unbalanced condition of the wash assembly (5) when the predetermined relationship is satisfied.