抄録
In recent years, several methods for decomposing the whole motion of a parallel multi-degrees-of-freedom (MDOF) system into motion modes have been proposed. A motion mode is a motion element that corresponds to a specific physical action, such as grasping, manipulating, and rotating. Modal decomposition is effective for the expression and analysis of a complicated motion. However, conventional methods can extract motion modes only if the arrangement of actuators in the system has spatial linearity and symmetry. Therefore, the actuators cannot be arranged arbitrarily when the conventional methods are applied. In order to solve this problem, a novel method for modal decomposition is proposed; this method is based on the discrete Fourier series expansion. The proposed method is applied to a parallel MDOF bilateral system in which the arrangement of actuators is spatially asymmetric. Finally, the validity of the proposed method is confirmed on the basis of the experimental results.