Positioning control of hydraulic cylinders through fuzzy logic method

In this thesis, sensitive positioning of hydraulic cylinders is targeted. In the study, following the emphasizing of the significance and the place of control techniques in today?s industry, studies carried out through fuzzy logic have been examined by scanning literatures. Basic parts used in hydraulic systems have been introduced. Solenoid and proportional valves have been used in the experiments. Fuzzy logic has been used in positioning control and rule base has been developed. Rule base has been formed with verbal definitions. The algorithms of fuzzy logic (membership functions) have been created in the fuzzy module of Matlab software. As a consequence of the experiments, solenoid valves which are not that sensitive due to its structure have been observed to get close to the values obtained by proportional valves when they are controlled through fuzzy logic method. The experiments have been implemented with unit order and sinusoidal signals. Solenoid valve has been compressed to 3% error tolerance as a result of unit order signal experiments; however, the best result has been obtained in the entry of 7% error tolerance. The best result in sinus signal experiments has been observed as 0,4 mm of error. In this experiment, the proportional valve used has been ramped with about 3,5 volts. When we examine the experiments, 3% error tolerance has been obtained easily. Once compared to solenoid valve experiments, it has been seen that better results have been obtained. When we examine the experiments carried out with sinus signals, it is seen that far better results than the experiments carried out with solenoid valves have been obtained. Looking at the results, it is seen that 0,12 mm error tolerance is within the acceptable limits.