Laundry machine control system for load imbalance detection and extraction speed selection

摘要

A control system for a laundry washing machine with a horizontal wash drum detects load imbalance in the drum and selects a proper rotation speed for the drum in a water extraction operation. A drive controller for the motor turning the drum detects a phase angle variation in the drive voltage and drive current applied to the motor as an indication of the load imbalance in the drum, and determines whether the detected load imbalance falls in one of a plurality of pre-defined load-imbalance zones. The drive controller then provides a signal indicating the detected imbalance zone to a machine controller of the washing machine. The machine controller selects a proper rotation speed for the extraction operation based on the detected imbalance zone, or alternatively initiates a load-redistribution operation to reduce the load imbalance.