WEIGH FEEDING SYSTEM WITH SELF-TUNING STOCHASTIC CONTROL

A weigh feeding system using a stochastic controller wherein the weight of material is sensed, and an estimate of the mass flow state of the material being discharged is created by use of a Kalman filter process. Plant noise processes and measurement noise processes, which affect the measured weight signal, are modeled as stochastic processes and are used, in combination with the sensed weight signal, to calculate the estimated mass flow state. The noise model is modified to account for disturbances. The estimated mass flow state signal is used to calculate a motor feedback signal which, in turn, is used to control the speed of the discharge apparatus. In this manner, the mass flow of the material actually being discharged is driven to a desired mass flow with minimum error variance in the presence of unavoidable plant and measurement noise. Self-tuning of the stochastic controller is employed to accurately determine parameters of the plant noise and measurement noise processes, and to compensate the controller for control dynamics. Feedback control tuning is also employed to monitor the set-point error in order to achieve quick response while maintaining smooth steady-state set point control.