FAST AND SLOW GENERATION OF A MULTILEVEL CONTROL FOR THE WOOD DRYING PROCESS

ABSTRACT

The dynamic characteristics of the wood drying process were represented by an actuator network and an internal model. These two subsystems are composed of a set of ordinary differential, partial differential and algebraic equations with adjusting operating functions. The formulation of the operating functions is based on interaction between air and the lumber board in a semi-industrial drying kiln. Using this internal model, it was possible to establish a state observer, a state predictor, and a reference model for which the boundary conditions were generated by the actuator network. Simulation results were obtained with a C++ software package. In order to implement the optimization techniques to the wood drying process, the two-level control structure was proposed and tested for a minimum drying time as a performance criterion. Numerical results confirm that the internal model and its operating functions were properly chosen.

Keywords and Phrases:

• actuator network
• distributed parameters system
• Euclidean norm
• fast and slow subsystems
• internal model
• mobile control volume
• operating functions
• variable structure system