Flexible virtual fixture enhanced by vision and haptics for unstructured environment teleoperation

Both manipulative accuracy and system safety are important for teleoperation. Traditional virtual fixture has good accuracy in fully known environment, however it is unable to handle suddenness (avoiding obstacles and etc.) in unstructured environment teleoperation which is crucial to system safety. In this paper we present the flexible virtual fixture enhanced by vision and haptics for unstructured environment teleoperation. Firstly, the flexible virtual fixture is proposed to deal with suddenness of unstructured environment, but the manipulation accuracy decreases. Secondly, vision is utilized for flexible virtual fixture to recognize unknown obstacles to improve the accuracy by selecting the proper flexible factor. Thirdly, haptics with virtual guidance force is used to assist human operator manipulation to further enhance the accuracy. Experimental results of sinusoid curve tracking with obstacles demonstrate that the proposed method has good performance in both manipulative accuracy and system safety for unstructured environment teleoperation.