Improvement of Motion Control Performance for a Power-Assist Lifting Device Using Wire-Driven Parallel Mechanism

Abstract

Recently, the shortage of skilled workers has required increasing efficiency for the operations of lifting, moving and setting heavy equipments in plant construction sites. For this purpose, we proposed a Power-Assist Lifting device (PAL) which is driven by a parallel wire mechanism, as one of the most effective means for utilizing the unique sensory skills of a human being and the physical power of a machine. The motion control technique of this device is based on the recursive identification of a Jacobian matrix. However, the decreased performance of the object motion caused by the identification error was observed. The objective of this study is to improve this motion control performance. In this paper, a motion control technique that has velocity feedback and estimation of velocities in horizontal and vertical directions is studied.