ABSTRACT:A Fuzzy Controller is used for the antisway tracking control of overhead cranes. Fuzzy Logic Controllers have been designed to deal with problems and situations where conventional control theories have failed. Fuzzy Logic Controllers have the capability of transforming linguistic information and expert knowledge into control signals. One of the main advantage is that its implementation process is comparatively simpler than conventional methods as it works on certain set of predefined rules which are simple if-then statements which are simple to understand as they are in common English language. The input parameters after being read from the sensors are fuzzified as per the membership function of the respective variables. These membership function curves are utilized to come to a solution and finally defuzzification is done to obtain a crisp output. KEYWORDS:Antisway Tracking Control, fuzzy Logic Controllers, linguistic information, Defuzzification, Fuzzification Overhead crane systems have been widely used for material transportation in many I.INTRODUCTION industrial fields, due to their low cost, easy assembly and maintenance. But its severely nonlinear properties bring about undesired swings, especially at take-off and arrival. Thus its automization create severe problem as they belong to a class of under actuated mechanical systems, i.e., they have fewer actuators than degrees of freedom. Overhead crane systems belong to the category of incomplete control systems, which only allow a limited number of inputs to control more outputs. Such uncontrolled oscillations cause both stability and safety problems. This drawback strongly constrains the operational efficiency and the application domain.For example, 2-D overhead cranes have one control input (a trolley driving force) and two system variables to be controlled (a horizontal trolley position and a load swing angle). This underactuation property results in a coupling effect between the load sway motion and the trolley travelling motion. In addition, uncontrolled load sway dynamics causes safety problems in crane systems, which makes it much more challenging to control them. Crane control systems have beendeveloped in such a way that the trolley is moved to a desired position as fast as possible while adequately suppressing the load swing angle II.LITERATURE SURVEY Since fuzzy logic controller can mimic human behaviour, many researchers applied fuzzy logic controller to control either overhead crane, gantry crane as well as rotary crane. A thorough literature overview was done on the usage of fuzzy logic controller as applied to the various crane systems. Lee, H. H. and Cho, S. K. This system is an incomplete control system because it has a smaller number of actuators than the number of controlled variables In order to simplify the modelling complexity, several assumptions have first to be made: Plastic deformation inthe system is ignored. The cable is treated as a weightless rigid body. The moment of inertia of the load is ignored and the load becomes a point mass. Therefore, the overhead crane system can be simplified to a cart-pendulum model with a variable pendulum length, as shown i
