Method for determining the mass of wet laundry in a laundry drum

摘要

A method for determining a mass of wet laundry in a washing machine drum being driven by an rpm-controlled universal motor is performed with the aid of controller variables. The drum is operated before and/or during a spin cycle within first, second and third phases in a mass determining segment. The drum is operated in the first phase with a delayed rpm rise up to a final rpm above an application rpm at which the laundry is applied to a wall of the drum, and near but below a resonant rpm of a drive system. The drum is operated in the second phase with a constant command rpm equal to the final rpm of a ramp. The drum is operated in the third phase with an rpm running down to a minimum rpm without being driven, and with the rpm still being high enough to prevent a previously developed ring of laundry from separating or more than slightly separating from the drum wall. A length of time is measured from a time when the drive is shut off until a time when the minimum rpm is reached, as a gauge for the mass of the laundry.