Positioning control of vibration systems such as flexible structures is one of the most fundamental technologies for mechanical structures. Different from feedforward control based methods, the use of LQ optimal regulator realizes the feedback control of vibrating parts of a controlled object. However, if the standard LQ optimal regulator is applied to long distance positioning problems, it requires much control energy in motion starting and the positioning error becomes large in settling. Therefore, its use is suitable for positioning settling and residual vibration reduction control in short distance problems. This study proposes a control method switching from a simple feedforward access control technique to the LQ optimal regulator for long distance problems. Especially, this paper mentions a proper switching method of the two control modes. The effectiveness of the proposed method is verified experimentally.
