Analytic fuzzy logic control of a rotary crane using evolutionary search for optimal fuzzy parameters

This paper implements fuzzy logic control of a rotary crane which makes lands of motion (rotation load hoisting boom hoisting) simultaneously. The goal is to transfer a load in a given time to a desired place minimizing the swing of the load at the end of a transfer. For each controllable degree of freedom of motion fuzzy logic controller is constructed utilizing analytic approach to fuzzy logic control synthesis. This avoids a problem of exponential growth infuzzy rules as the number of variables increases. For that purpose instead of defining a fuzzy rule base analytic function is used that determines the positions of the centres of the output fuzzy sets. Input variables in each analytical fuzzy logic controller are position and velocity errors of coresponding controllable and each directly uncontrollable (swing of a load) degree of freedom. Some of the free fuzzy sets parameters were obtained using evolutionary algorithms optimization method.