الفهرس 
Hydraulic actuatorsOnly 14 pages are availabe for public view
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Abstract
The efficiency of hydraulic position control in industrial applications is essential factor which affect productivity of earth-moving equipment, pressing machine and most hydraulic devices with accurate positioning systems. However the conventional controlled hydraulic systems have problem of low energy efficiency, hence, a new technique was developed to enhance a position control of a hydraulic cylinder using servo motor drives. A servo motor drive is used to control the pump speed through a PID controller and fuzzy logic controller where the cylinder position feedback is used as the control reference. A hydraulic setup is simulated where a two staged cylinder is used as an actuator and load source. The proposed system is used to as an alternative to variable displacement pumps with proportional valve to control the cylinder position. The result shows a good positioning accuracy with high gain of energy efficiency.
This Work Objective is to enhance the performance of position control in the hydraulic cylinder at different patterns of load using servo motor drives. The thesis consists of six chapters and the summary of each chapter is as the following. Chapter one consists of introduction on the thesis with information about most used components in this thesis. Chapter two contains a survey of the published papers in the field of control the position of a hydraulic system, AC servo drives systems and ended this chapter with the problem statement. Chapter three contains the theoretical study in electro-hydraulic control system by building mathematical modeling and simulation using computer. As well as, gives a proposal for two different control techniques one of them is PID controller and the other fuzzy logic control to reduce the position error of hydraulic cylinder at different pattern of load and enhance the system position. Chapter four exposed to design an experimental test rig that simulate the real system and its major components are main cylinder, load cylinder that make a different pattern of load on the main cylinder, proportional relief valve, servo motor, servo drive, hydraulic control valves, hydraulic power unit, all necessary electrical component and electronic interfaces for operating and testing. Chapter five provides laboratory experiments that show its result advantages of using fuzzy controller in improving the position control of hydraulic cylinder using servo motor drives and finally chapter six contains conclusions and future works.