Abstract
A hydraulic motor servosystem is useful for control of high power and quick response such as drawing control of horizontal continuous casting machine at steel making process. But, it is necessary to accomplish stable control with highspeed. In this paper, the dynamic characteristics of hydraulic motor servosystem is studied by using mathematical models of its components. It is proposed to use a simple bypass valve for getting stable control which is able to damp the hydraulic servosystem. The effectiveness of the proposed method is confirmed by a numerical simulation and an actual experiment.