This thesis is concerned with the study of a hydraulic load simulator, which can simulate hydraulic systems as those operated under given load profile of a desired mass-damper system. Two cylinders are connected in a same axis and the rods are rigidly connected with each other. The time delay control(TDC) method is applied to the system following the desired trajectory. It is shown that the time delay control is effective to a load simulator to obtain good tracking performances of a load profile regardless of wide range of disturbances. It is also shown that TDC controller gives satisfactory appearance of given load-speed profile of a load simulator. The effects of servovalve underlap, flexible coupling and oil compressibility on the tracking perfomance of a load simulator are discussed.
