A controller design method based on functionality

Abstract—Robots are expected to expand their range of activities to human environment. Robots in human environment need redundancy for environmental adaptation. Furthermore, they have to automatically modify their controllers in response to varying conditions of the environment. Therefore, the authors have proposed a method to design a hyper-DOF control system efficiently. The method decouples a large control system into small independent components so-called function. Motion of the entire control system is expressed as superposition of multiple functions. Combination of some functions realizes many patterns of motion. Hence various motions are realized with much smaller efforts on controller design. Additionally, the controller design is explicit since a controller and a function corresponds directly. This study expands the method to multi-DOF robots in threedimensional space since the conventional method was limited to a multi-robot system in one-dimensional space. A new problem of interference among function-based systems occurs along with the expansion. Disturbance observer is applied on each actuator to eliminate the interference. Procedures of controller design under varying conditions are also shown. The proposed method is applied to a grasping manipulator with 18DOF. Its experimental results show validity of the method