On Control Systems for Human-Machine Cooperative Systems with Stable Tool Dynamics

摘要

In this paper, control system design of human-machine cooperative systems considering maneuverability is investigated. First, the representative past studies are reviewed and essential characteristics of controlled systems are summarized as 4 transfer functions: the tool dynamics, the reaction force transfer function, the maneuver transfer function, and the transfer function of object dynamics variation. Secondly, parametrization of a general structure of control systems stabilizing the tool dynamics is presented. On the basis of the parametrization, it is clarified that the control systems have two degrees of design freedom, and the relationships among those 4 transfer functions are derived and discussed. Thirdly, it is experimentally verified that previous observations by the authors on dynamics self-shaping characteristics of a human operator in a manual control system are also found similar in human-machine cooperative systems, and that the knowledge can be used for specifying desirable frequency characteristics of the maneuver transfer function. Then, a control design procedure utilizing the full 2 degree of freedom is proposed. An example human-machine cooperative system is designed so that its maneuver transfer function is shaped suitably corresponding to the dynamics self-shaping characteristics of the operator, as well as the transfer function of object dynamics variation is compensated to have a gain large enough to enable the operator to recognize a small variation. Finally, experiments are carried out, to confirm the validity of the proposed design procedure.