Parallel Control Method for Manipulators by Using FEM


 環境や作業条件の変化に伴い、制御システムのソフトウェアは変えずにハードウェアのみを様々な形状に再構成する、ロボットの並列制御が近年注目を浴びている。このような環境に対する適応性に優れたロボットシステムの概念はParallel Roboticsと呼ばれ、宇宙、海中、採鉱、建築などの作業状況が時々刻々変化する場での応用が期待されている。これは、システムの小サイズ化のみならず、遠隔操作中に一部の要素が機能を失ったとしても全体系の機能が維持できる、高い冗長性を持つことが大きな特長である。

In this paper, the Finite Element Method (FEM) is proposed for application to a control system of robotic manipulators. The equations of motion conducted by Newton-Euler method need to be changed when the shape of the system or the quantity of the linked members is suddenly changed during the control process. Meanwhile, as the entire system is considered as a continuum and subdivided into discrete elements in the FEM, the control software using the FEM becomes capable of expressing lack or disability of constituent members of the system only by changing input data. Particularly, by applying so called the Shifted Integration technique, a simple link structure of a half pin joint and a rigid bar can be expressed simply by shifting a numerical integration point in a linear Timoshenko beam element. An inverse problem theory using the Shifted Integration technique is described in this paper along with a simple simulation result. A possibility of using the FEM in the field of Parallel Robotics is suggested.