Interactive feedback for variable equation specifications
Software instructions stored on a memory device and executable by a processor generate a plurality of models to simulate a process entity. The models include equations that mathematically represent the functionality of the process. Moreover, the models are configured to accurately represent the functionality of the process. Instructions determine whether the equations of the models are solvable after each change made to the models and indicate the result of the determination of solvability of the equations. Changes to the plurality of models are suggested that may render the equations solvable if the equations are determined to be unsolvable.
1. A system for controlling an industrial process comprising:
a processor configured to be coupled to one or more control elements in the industrial process, the control elements configured to control one or more aspects of the industrial process;
a memory device coupled to the processor;
software instructions stored on the memory device and executable by the processor, said instructions comprising:
instructions for generating a plurality of models on a flowsheet, said plurality of models including equations that mathematically represent functionality of the industrial process;
instructions for analyzing the flowsheet in response to a modification thereof by determining whether the equations of the plurality of models are solvable after the modification, said analyzing performed before attempting to solve the equations, wherein the analyzing locates inefficiencies in the industrial process;
instructions for suggesting changes to the plurality of models that may render the equations solvable in response to determining the equations are unsolvable, wherein the suggested changes improve or eliminate the located inefficiencies in the industrial process upon a user making the suggested changes; and
instructions for solving the equations in response to determining the equations are solvable for simulating the functionality of the industrial process in accordance with the models on the modified flowsheet, said solving performed without any intervening actions after the equations are determined to be solvable,
wherein the processor provides a control signal to one or more of the control elements in the industrial process to adjust operation of at least a portion of the industrial process in order to operate the industrial process in accordance with the models on the modified flowsheet.
2. The system of claim 1 , wherein the equations are determined to be under-specified, and suggesting changes to the plurality of models comprises suggesting variables to be specified to make the equations of the plurality of models solvable.
3. The system of claim 1 , wherein the equations are determined to be over-specified and suggesting changes to the plurality of models comprises suggesting specified variables to be freed to make the equations of the plurality of models solvable.
4. The system of claim 1 , wherein determining whether the equations of the plurality of models are solvable comprises performing a sequence of row and column permutations.
5. The system of claim 1 , the software instructions further comprising:
instructions for analyzing a subset of the equations in response to determining the equations of the plurality of models are unsolvable by determining whether the equations of the subset are solvable after the modification, said analyzing the subset of equations performed before attempting to solve the subset of equations;
instructions for suggesting changes to the plurality of models that may render the equations of the subset solvable in response to determining the equations of the subset are unsolvable; and
instructions for solving the equations of the subset in response to determining the equations of the subset are solvable, said solving the equations of the subset performed without any intervening actions after the equations of the subset are determined to be solvable.
6. The system of claim 5 , the software instructions further comprising instructions for re-executing said instructions for analyzing the flowsheet, said instructions for analyzing the subset of the equations, said instructions for suggesting changes, said instructions for solving the equations, and said instructions for solving the equations of the subset until all equations of the plurality of models are solved.
7. The system of claim 1 , wherein said solving comprises:
(i) setting an initial value of all variables of the equations at time zero to a steady-state equation,
(ii) advancing time by one time step,
(iii) fixing at least one variable of the equations to a value thereof from the previous time step,
(iv) solving the equations for new values of the variables and one or more states, and
(v) repeating steps (ii)-(iv).
8. One or more tangible, non-transitory computer-readable media having executable instructions stored thereon that, when executed by a processor, the processor performs a method of controlling an industrial process comprising:
generating a plurality of models on a flowsheet, said plurality of models including equations that mathematically represent functionality of the industrial process;
analyzing the flowsheet in response to a modification thereof, before any other actions, by determining whether the equations of the plurality of models are solvable after the modification, wherein the analyzing locates inefficiencies in the industrial process;
suggesting changes to the plurality of models that may render the equations solvable in response to determining the equations are unsolvable, wherein the suggested changes improve or eliminate the located inefficiencies in the industrial process upon a user making the suggested changes; and
solving the equations in response to determining the equations are solvable to simulate the functionality of the industrial process in accordance with the models on the modified flowsheet, said solving performed without any intervening actions after the equations are determined to be solvable,
wherein the processor provides a control signal to one or more control elements in the industrial process to adjust operation of at least a portion of the industrial process in order to operate the industrial process in accordance with the models on the modified flowsheet, wherein the processor is configured to be coupled to the control elements, and wherein the control elements are configured to control one or more aspects of the industrial process.
9. The computer-readable media of claim 8 , wherein suggesting changes to the plurality of models includes adjusting which variables of the models are free and which variables of the models render the equations solvable.
10. The computer-readable media of claim 8 , wherein suggesting changes to the plurality of models includes adjusting one or more variables of the models to be free when all of the variables are previously fixed.
11. The computer-readable media of claim 8 , wherein determining whether the equations of the plurality of models are solvable comprises performing a sequence of row and column permutations.
12. The computer-readable media of claim 8 , wherein the executable instructions stored thereon, when executed, perform the method of simulating the industrial process, further comprising:
analyzing a subset of the equations, before any other actions, in response to determining the equations of the plurality of models are unsolvable by determining whether the equations of the subset are solvable after the modification;
suggesting changes to the plurality of models that may render the equations of the subset solvable in response to determining the equations of the subset are unsolvable; and
solving the equations of the subset, before any other actions, in response to determining the equations of the subset are solvable.
13. The computer-readable media of claim 8 , wherein said solving the equations comprises:
(i) setting an initial value of all variables of the equations at time zero to a steady-state equation,
(ii) advancing time by one time step,
(iii) fixing at least one variable of the equations to a value thereof from the previous time step,
(iv) solving the equations for new values of the variables and one or more states, and
(v) repeating steps (ii)-(iv).
14. A processor executable method of controlling an industrial process comprising:
generating a plurality of models on a flowsheet, said plurality of models including equations that mathematically represent the functionality of the industrial process;
analyzing the flowsheet in response to a modification thereof by determining whether the equations of the plurality of models are solvable after the modification, said analyzing performed before attempting to solve the equations, wherein the analyzing locates inefficiencies in the industrial process;
suggesting changes to the plurality of models that may render the equations solvable in response to determining the equations are unsolvable, wherein the suggested changes improve or eliminate the located inefficiencies in the industrial process upon a user making the suggested changes;
solving the equations in response to determining the equations are solvable for simulating the functionality of the industrial process in accordance with the models on the modified flowsheet, said solving performed before subsequent modifications of the flowsheet;
analyzing a subset of the equations in response to determining the equations of the plurality of models are unsolvable by determining whether the equations of the subset are solvable after the modification, said analyzing the subset of equations performed before attempting to solve the equations of the subset;
suggesting changes to the plurality of models that may render the equations of the subset solvable in response to determining the equations of the subset are unsolvable; and
solving the equations of the subset in response to determining the equations of the subset are solvable, said solving the equations of the subset without any intervening actions after the equations of the subset are determined to be solvable,
wherein a processor executing said method provides a control signal to one or more control elements in the industrial process to adjust operation of at least a portion of the industrial process in order to operate the industrial process in accordance with the models on the modified flowsheet, wherein the processor is configured to be coupled to the control elements, and wherein the control elements are configured to control one or more aspects of the industrial process.
15. The method of claim 14 , wherein suggesting changes to the plurality of models includes adjusting which variables of the models are free and which variables of the models render the equations solvable.
16. The method of claim 14 , wherein suggesting changes to the plurality of models includes adjusting one or more variables of the models to be free when all of the variables are previously fixed.
17. The method of claim 14 , wherein determining whether the equations of the plurality of models are solvable comprises performing a sequence of row and column permutations.
18. The method of claim 14 , further comprising repeating said analyzing the flowsheet, analyzing the subset of the equations, said suggesting changes to the plurality of models that may render the equations solvable, said suggesting changes to the plurality of models that may render the equations of the subset solvable, said solving the equations, and said solving the equations of the subset until all equations of the plurality of models are solved.
19. The method of claim 14 , wherein said solving comprises:
(i) setting an initial value of all variables of the equations at time zero to a steady-state equation,
(ii) advancing time by one time step,
(iii) fixing at least one variable of the equations to a value thereof from the previous time step,
(iv) solving the equations for new values of the variables and one or more states, and
(v) repeating steps (ii)-(iv).