Object-transportation control for a human-operated robotic manipulator

Because of the difficulty in realizing fully automated robotic systems from the viewpoint of cost efficiency and available current technologies, human-robot cooperative system has been widely studied to date. This paper deals with a human-operated robotic manipulator that supports the object-transportation task in houseworks and factories. A new controller design that provides two fundamental functions is developed; obstacle avoidance and stable transportation of object, even when the human operator makes mistakes in operation. A general type of three-degree-of-freedom robotic manipulator is considered, which moves in a horizontal plane and can be operated by a joy-stick controller. To achieve both the obstacle avoidance and the stable transportation of object with providing a function that incorporates the human-operatorpsilas command, we propose a model reference control approach in which the robot follows a desired trajectory generated by a reference model. The effectiveness of the proposed method is confirmed by experiments where several unskilled operators operate the manipulator for transporting a object in a narrow space.