Patent attributes
Aspects are provided for positive displacement pumps and methods and systems for controlling such pumps for dispensing at a flow rate based on a downstream flow sensor. A pump controller determines a targeted motor speed for a flow rate set point based on a flow rate function. The pump controller determines a predicted movement time for a motor of the pump to change from a current motor speed to the targeted motor speed, a predicted wait time to reach a flow rate corresponding to the targeted motor speed, and a measurement time after the wait time. The pump controller controls the positive displacement pump according to consecutive control cycles, each control cycle includes a pump movement sub-cycle, a wait sub-cycle, and a measurement sub-cycle. The pump controller determines a measured flow rate during the measurement sub-cycle. A subsequent control cycle is based on the measured flow rate.
