Imaginary motor control for the table of machine tools with 3 linear servo motors

The linear motor driving mechanism is adopted for positioning mechanism of the machine tools to realize high speed and precise positioning, because of frictionless and no backlash. When the table of machine tools is driven at high speed, two or more linear motors are used for the same axis to obtain the high thrust power. In case of using more linear motors, however, the position of the table changes because the thrust force of each linear motor doesn't become the same. In addition, this causes to generate micro vibration and to change the velocity of each linear motor due to yawing around the center of gravity. In this study, the imaginary motor control method was proposed with three linear motors for driving table to control the position of the gravity, the vibration and yawing. From the results of simulation and the experiments, it is confirmed that the proposed method can control the position of the gravity, the vibration and yawing independently.