Cautious stochastic computer control applied to concrete mixing

An application of direct digital control of a concrete mixing process is presented. The process which is irreversible is modelled as a linear stochastic system. The control problem is formulated as a final value control problem. A general final value prediction problem is formilated and solved. The regulator becomes an adaptive stochastic regulator. Its control actions are based on the uncertainty in the control-error which is calculated as the difference between the setpoint and the predicted final value. The resulting algorithm is implemented on a small minicomputer based control system and is used in every day production since more than a year ago.