A virtual environment display with constraint feeling based on position/force control switching

This paper presents a technique for the design of force-reflecting systems which simulate realistic virtual environments. In tasks that involve interactions with the environment, such as assembling blocks and inserting pegs in holes, there are many sliding motions along intervening edges and faces. To perform these tasks, force sensation is the most important information to recognize the interactions between the objects. The authors previously proposed a system that realizes constraints due to the environment by modeling the interaction forces. However, the modeling of the complex contact forces required a servo loop that took a long time to execute. In this paper, the authors introduce a virtual environment display system which uses a switching position/force control mode. The improved performance of this new system presents a more realistic simulation to the operator. Finally the authors report some experimental results which confirm the validity of the proposed method