Control System Design for a Mixing System with Multiple Inputs
AssigneeHalliburton Energy Services, Inc.
InventorsJason D. Dykstra, Justin A. Borgstadt
Life of this patent
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Abstract
A method for mixing at least two materials is provided. The method comprises introducing the at least two materials into a physical system and combining the at least two materials to form a mixture thereof. The method also comprises independently controlling a desired characteristic of the mixture and a desired parameter of the physical system, wherein the controlling is based in part on estimating a disturbance, wherein the estimating the disturbance is based on processing an error term determined by subtracting a modeled parameter of the physical system from a corresponding sensed parameter of the physical system.
Claims20
A method for mixing at least two materials, comprising:
- introducing the at least two materials into a physical system;
- combining the at least two materials to form a mixture thereof;
- and
- independently controlling a desired characteristic of the mixture and a desired parameter of the physical system, wherein the controlling is based in part on estimating a disturbance, wherein the estimating the disturbance is based on processing an error term determined by subtracting a modeled parameter of the physical system from a corresponding sensed parameter of the physical system.
A method for mixing at least two materials, comprising:
- determining a commanded combined mass flow rate of the at least two materials into a first tank [commanded dmin/dt];
- determining a commanded combined volume flow rate of the at least two materials into the first tank [commanded dvin/dt];
- determining an estimate of a disturbance, wherein the disturbance is associated with at least one of an inaccuracy of a design estimate of a control system parameter and an unmeasured control system parameter;
- and
- independently controlling a density of a mixture of the at least two materials in the first tank [ρ12] and a volume flow rate of the mixture out of the first tank [dv12/dt], wherein the controlling is based on the commanded dmin/dt, based on the commanded dvin/dt, and based on the estimate of the disturbance.
A control system for mixing at least two materials in a physical system, comprising:
- a first tank;
- at least two actuators, each actuator being operable to introduce a material into the first tank to form a first mixture;
- a density sensor operable to provide a sensed density output of the first mixture;
- and
- a controller to control the at least two actuators to obtain a density of the first mixture and a volume flow rate of the first mixture, wherein the density is controlled independently from the volume flow rate, the controller comprising:
- a flow modulator component to output control commands to the two actuators based on a commanded combined mass flow rate of the materials into the first tank and based on a commanded combined volume flow rate of the materials into the first tank,
- a density controller component to determine the commanded combined volume flow rate of the materials into the first tank, and
- a density observer to determine a first estimation of a disturbance and to determine an estimation of the density of the first mixture based on the estimation of the first mixture, based on the sensed density output, based on the commanded combined mass flow rate of the materials into the first tank, and based on a model of the first tank,
- wherein the density controller component determines the commanded combined volume flow rate of the materials into the first tank based on a commanded density input, based on the estimation of the density of the first mixture, and based on the first estimation of the disturbance.
Dependencies are inferred from the claim text.