Modelling and optimisation of a refining process for fibre board production

Abstract

For many processes in the pulp and paper industry there exist no reliable analytical models, but qualitative linguistic expert knowledge and data from on-line and laboratory measurements. Knowledge about the wood chip refiner in fibre board production is used to formulate the if-parts of Takagi–Sugeno fuzzy rules. Laboratory and on-line data are then used to fit the then-parts of these rules. The rule-based model serves as a soft sensor that enables the operators to manually control and optimise this process. An optimisation module based on sequential quadratic programming and/or simulated annealing automates this process. All modules are integrated in the commercial Siemens tool WinCC.