Method and device for controlling production of a mixture of components, in particular a mixture with pre-mix dead volumes

A device for producing and controlling production of a mixture M of n components, the device comprising:

• transport channels for transporting the components to be mixed into a main channel connected to a place for receiving the mixture M;
• means for controlling flow rates of the components in each transport channel;
• means for continuously measuring, in the main channel, representative parameters of the mixture M being produced;
• means for calculating proportions u of the components involved in the mixture;
• and
• an estimator connected to the means for calculating portions of the components;
• the estimator comprising programmed means for producing an estimate of the properties of the components using the measurements of the properties of the mixture that are measured by the measurement means, and the calculation means comprises programmed means for calculating, using the estimate, the proportions u of the components involved in the mixture so as to obtain a mixture having predetermined properties y;
• and
• wherein the programmed means of the estimator is configured to implement the following operations:
• (i) at time t=0:
• (1) determine a matrix B representing a number m of the properties y of the n components, and
• (2) determine a reference recipe ū from predetermined minimum and maximum thresholds and/or from the predetermined target values, such that properties Bū of the mixture lie between said predetermined thresholds and/or, for m′ of them, where m′≦n−1, are equal to predetermined target values,
• ū, being a vector of dimension n, representing the proportions of the various components involved in the composition of the mixture, where Σi=1nūi=1;
• (ii) at time t′=t+Δt:
• (1) measure the properties ymes of the mixture M obtained by applying the recipe calculated at time t=0, and
• (2) deduce therefrom a corrected matrix {circumflex over (B)}, representing the estimate of the properties of the components.

The device according to claim 25, wherein the optimizer implements an optimization procedure to determine the recipe u in such a way that the properties {circumflex over (B)}u of the mixture lie between said predetermined thresholds and/or, for m′ of them, are equal to said predetermined target values, wherein the optimizer includes a programmed means to implement the following operations:

• (a)—determine the solution of a complete regulation problem P0, the solution consisting of recipe u taking into account the constraints on the proportions of the components and constraints on the properties of the mixture, and
• apply the recipe u if the complete regulation problem P0 is solvable;
• (b)—determine recipe u for which a minimal regulation problem P1 is solved, if the complete regulation problem P0 is not solvable, which takes into account only constraints on the problem P0 that are defined as priority constraints;
• the problem P1 involving a succession of normally feasible optimization problems, the criteria of which consist in penalizing the violation of said priority constraints so as to define achievable new values for the priority constraints;
• (c)—determine a recipe u for which a regulation problem P2 is solved, if the minimal regulation problem P1 is solvable, which takes into account said achievable new values of the priority constraints of the problem P0 and also non-priority constraints of the problem P0;
• the problem P2 involving an optimization problem, the criteria of which consist in penalizing the violation of non-priority constraints so as to define achievable new values for the non-priority constraints, or
• apply the current recipe u if the minimal regulation problem P1 is not solvable;
• (d)—determine recipe u for which a regulation problem P3 is solved, if the regulation problem P2 is solvable, which takes into account said achievable new values of the priority constraints of the problem P0 obtained in step (b), said achievable new values of the non-priority constraints obtained in step (c) and also all other non-priority constraints of the problem P0 not treated by the problems P1 and P2;
• the problem P3 involving a succession of normally feasible optimization problems, the criteria of which consist in penalizing the violation of said other non-priority constraints so as to define achievable new values for the other non-priority constraints, or
• apply the recipe obtained by the problem P1 if the regulation problem P2 is not solvable;
• and
• (e) apply recipe u that is the solution of the problem P3 if the regulation problem P3 is solvable, otherwise apply recipe u that is the solution of the problem P2.