Development of a Self-Tuning Fuzzy Logic Controller for a Rotary Dryer

It is well known that the control of a rotary dryer is difficult due to long delay times of the process. The main target of this research was to find a self-tuning technique for tuning the parameters of the fuzzy logic controller, which has been developed to the pilot plant rotary dryer located in the Control Engineering Laboratory at the University of Oulu. The aim is to improve the performance of the FLC by making the responses more robust to the input disturbances of the process, mainly to the input moisture of solids. First, the literature review is made in order to see the current situation of the selftuning FLC’s, and then one self-tuning technique presented in the literature is selected and applied to the tuning of the hybrid PI-FLC and of the pure FLC used in the control of the rotary dryer. The resulting control behaviour has been examined with simulations and the comparison with the results achieved with the FLC’s without selftuning is made.