摘要 |
<p>A control system for mixing at least two materials in a physical system, for example cement and water for a well bore, having two or more tanks comprises at least two actuators, each actuator being operable to introduce a material into a first tank to form a first mixture, the first mixture flowing into a second tank to form a second mixture and a controller operable, based on a commanded input, to control the at least two actuators to obtain a density of either the first mixture or the second mixture and a volume flow rate of the second mixture out of the second tank, wherein the density is controlled independently from the volume flow rate, and wherein the commanded input comprises a commanded combined volume flow rate and a commanded combined mass flow rate of the materials passing through the actuators into the first tank.</p> |