Dynamic inventory tank control
AssigneeHoneywell International Inc.
InventorJOSEPH LU
Life of this patent
Estimating the term…
Abstract
Methods, devices, systems and software products for controlling the properties and volume of materials in a tank having at least one inlet pipe and at least one outlet pipe. Based on whether inlet flows into the tank and outlet flows from the tank are equal, either first or second sets of differential equations are used to determine step responses for use in a model predictive control process, and control actions are determined and executed based on the model predictive control outputs. A determination of whether inlet flows and outlet flows are equal or unequal is made at each iteration.
Claims20
A method of controlling a tank, the tank holding a volume of tank material having tank material properties, the tank receiving inlet flow material having inlet flow material properties from at least one inlet flow pipe, and releasing an outlet flow material to at least one outlet flow pipe, the method comprising:
- determining whether a mass of the inlet flow material equals a mass of the outlet flow material and in response:
- if the mass of inlet flow material equals the mass of outlet flow material, applying a first set of ordinary differential equations and analytical or numerical solutions thereof to determine a first tank step response model for the tank volume of material and for the properties of the tank material;
- if the mass of inlet flow material does not equal the mass of outlet flow material, applying a second set of ordinary differential equations and analytical or numerical solutions thereof to determine a second tank step response model for the tank volume of material and for the properties of the tank material;
- performing a model predictive control process using either the first tank step response model or the second tank step response model to determine control actions for one or more valves or pumps controlling the at least one inlet flow pipe and at least one outlet flow pipe;
- and
- executing a first one of the control actions to control flow through the at least one inlet flow pipe or the at least one outlet flow pipe before proceeding to a next time iteration.
A method of controlling a tank, the tank holding a volume of tank material having tank material properties, the tank receiving inlet flow material having inlet flow material properties from at least one inlet flow pipe, and releasing an outlet flow material to at least one outlet flow pipe, the method comprising:
- receiving an instruction to change the tank material properties;
- during a first time period, determining that a mass of the inlet flow material does not equal a mass of the outlet flow material and, in response:
- applying a first set of ordinary differential equations and analytical or numerical solutions thereof to determine a first tank step response model for the tank volume of material and for the properties of the tank material;
- performing a model predictive control process using the first tank step response model to determine first control actions for one or more valves or pumps controlling the at least one inlet flow pipe and at least one outlet flow pipe;
- and
- executing a first one of the first control actions to control flow through the at least one inlet flow pipe or the at least one outlet flow pipe;
- during a second time period after the first time period, determining that a mass of the inlet flow material does equal a mass of the outlet flow material and, in response:
- applying a second set of ordinary differential equations and analytical or numerical solutions thereof to determine a second tank step response model for the tank volume of material and for the properties of the tank material;
- performing a model predictive control process using the second tank step response model to determine second control actions for one or more valves or pumps controlling the at least one inlet flow pipe and at least one outlet flow pipe;
- and
- executing a first one of the second control actions to control flow through the at least one inlet flow pipe or the at least one outlet flow pipe.
A controller for controlling a tank, the tank holding a volume of tank material having tank material properties, the tank receiving inlet flow material having inlet flow material properties from at least one inlet flow pipe, and releasing an outlet flow material to at least one outlet flow pipe, there being at least one flow controlling device in the inlet flow pipe and the at least one outlet flow pipe, controller configured to:
- determine whether a mass of the inlet flow material equals a mass of the outlet flow material;
- and in response:
- if the mass of inlet flow material equals the mass of outlet flow material, apply a first set of ordinary differential equations and analytical or numerical solutions thereof to determine a first tank step response model for the tank volume of material and for the properties of the tank material;
- if the mass of inlet flow material does not equal the mass of outlet flow material, apply a second set of ordinary differential equations and analytical or numerical solutions thereof to determine a second tank step response model for the tank volume of material and for the properties of the tank material;
- perform a model predictive control process using either the first tank step response model or the second tank step response model to determine control actions for one or more valves or pumps controlling the at least one inlet flow pipe and at least one outlet flow pipe;
- and
- execute a first one of the control actions before proceeding to a next time iteration by issuing or changing a control signal to the at least one flow controlling device to control flow through the at least one inlet flow pipe or the at least one outlet flow pipe.
Dependencies are inferred from the claim text.