Patent ID: 7920930
Filing Date: 2011-04-05
Classification: G05B

Abstract:
1. A method for controlling the transfer of a material into a container without overshooting a set point indicative of the container being filled to a desired amount using a feedback controller which generates a controller output signal which is communicated to a variable output device by which the flow of material into the container may be varied in accordance with the controller output signal; the method comprising the steps of: measuring a process variable indicative of the amount of material added to the container; calculating an error signal by comparing the process variable to the set point; if the error signal is less than or equal to zero, setting the controller output signal to zero to prevent flow of material through the variable output device and into the container; if the error signal is positive, calculating the controller output signal using a polynomial equation, which includes the error signal raised to an exponential term reduced by a bias tuning parameter, and if the value of the controller output signal is calculated as equal to or less than zero, setting the controller output signal to zero; communicating the controller output signal to the variable output device to control the flow of material therethrough and into the container without overshooting the set point; and repeating the steps until the controller output signal communicated to the variable output device is zero.