EXPERIMENTAL EVALUATION OF TIME-VARYING IMPULSE SHAPING WITH A 2-LINKFLEXIBLE MANIPULATOR

In the authors' previous paper,(10) an input shaping method was presen ted to reduce motion-induced vibrations effectively for various classe s of flexible systems. In this paper, the effectiveness of the shaping method is experimentally demonstrated with a two-link flexible manipu lator system. The manipulator for experiments includes two revolute jo ints and two flexible links, and moves on a vertical plane under gravi ty. An analytic model is developed considering the flexibility of the system and its joint stiffness in order to derive an appropriate estim ation of dynamic modal properties. The input shaping method used in th is work utilizes time-varying modal properties obtained from the model instead of the conventional input shaping method which employs time-i nvariant modal properties. A point-to-point motion is tested in order to show the effectivess of the proposed shaping method in vibration re duction during and after a given motion. The given reference trajector ies are shaped to suppress the motion induced vibration. The test resu lts demonstrate that the link vibration can be greatly suppressed duri ng and after a motion, and the residual vibration reduction was observ ed more than 90% by employing this time-varying impulse shaping techni que.