Improvement of the vibration damping performance for parallel wire type positioning systems (technique with natural frequency control and tuned mass damper)

Parallel wire type positioning systems, which consist of several tensioned wires in the plane, have many practical applications in industrial fields. However, the conventional systems are easy to vibrate in the direction perpendicular to the wire plane, and this problem limits the use of the system, in spite of a lot of their advantages. For this reason, a new parallel wire type positioning system with a vibration suppression mechanism (tuned mass damper: TMD) is developed in this study. However the TMD is effective only for the object with a constant resonance frequency, whereas the parallel wire systems generally have a variable resonance frequency depending on the wire tensions. Therefore, authors have developed new technique which can control both the position (attitude) and the natural frequency of the object simultaneously. This paper first describes the detail of the proposed technique, then effectiveness of the technique is verified through several experiments. © 2012 The Japan Society of Mechanical Engineers.