Patent ID: 8176947

Claim:
A method for filling a target container with a predetermined target mass of a free-flowing substance from a reservoir using a dosage-dispensing device to fill the target container with measured doses of the substance, the dosage-dispensing device comprising a valve which allows a mass flow rate of the substance from the reservoir into the target container to be varied, a time-keeping device, a balance, and a controller unit to control the valve, the controller unit including an adjustment module in which a desired mass flow rate is stored, the method comprising the steps of: determining a mass tolerance for the predetermined target mass and the desired mass flow rate; beginning a filling process by starting to measure elapsed time using the associated time-keeping device, starting to measure the mass of the substance present in the target container using the balance, and opening the valve; and adjusting the flow of the substance, at a predetermined elapsed time, by performing in the adjustment module, the substeps of: determining the mass flow rate, using an adaptive filter in the adjustment module; calculating a difference, if any, between the determined mass flow rate and the desired mass flow rate; calculating a mass flow adjustment, defined as a difference between the desired mass flow rate and an estimated mass flow rate, and adjusting the mass flow rate based on the calculated difference, by increasing the mass flow rate by the mass flow rate adjustment if the determined mass flow rate is less than the desired mass flow rate and by decreasing the mass flow rate by the flow rate adjustment if the determined mass flow rate is greater than the desired mass flow rate.