S. Pezeshki - University of Tabriz/ Department of Electrical and Computer Engineering, Tabriz, Iran
A. Aminzadeh Ghavifekr - University of Tabriz/ Department of Electrical and Computer Engineering, Tabriz, Iran
S. Badalkhani - University of Tabriz/ Department of Electrical and Computer Engineering, Tabriz, Iran

In this study, an Improved Fuzzy Controller using Sliding Mode Concept (IFCSMC) is employed to control anunderactuated overhead crane system. As we know fuzzy algorithms do not need the complex dynamic model ofsystem, but fuzzy controller of this paper uses trolley position and load swing angle information instead to design thefuzzy controller. Innovation of the proposed controller is using three experimental rules that utilize the appropriatecontrol signal value of last level for determining the control signal value of new level which depends on difference oferror (position error) in these levels. The merits of proposed algorithm in comparison with conventional fuzzy controlare decreasing the time of reaching to desire value and reducing sensitivity of system when fuzzy rules are changed.External disturbances, such as the wind and the hit, which always deteriorate the control performance, are alsoconsidered to verify the efficiency of the proposed improved fuzzy algorithm. Simulations results of the developedalgorithms that demonstrate the feasibility and effectiveness of the proposed controller are presented.

Improved Fuzzy Algorithm, Sliding Mode, Overhead Crane System