Introduction of grasp machines to underwater construction promotes mechanization of setting and removing works. In grasp operation, it is necessary to confirm the shapes and the positions of objects. As naked eye or TV camera is useless in turbidity such as the underwater in port area, an operator hardly carries out tele-operated grasp work. Thus, it is required that tele-operation method adapted for unclear environment using other information which is substitutable for visual information.
　Therfore, we are studying the tele-operation system of grasp machine- by groping using tactile sense substituting for visual information. This system indicates contact information by the painted color painted on the CG gripper drawn on the monitor, visualizes the image of an object by the contact points between the gripper and the object, and feeds back contact and grasp feeling to the operator by bilateral control. Furthermore, for preventing unintentional motion of objects by groping, when the gripper detects contact then the automatic stop control is applied to the gripper. Combining these vision compensations and automatic stop control, we have constructed manipulation aid system for unclear environment.
　For the experiment of this system, we have developed a master-slave mddel of a gripper. Using this model, we have done grasp experiments that removing scattered blocks and gathered smaller blocks by naked eye and tactile sense. As a result, the validity of this manipulation aid system is verified by the experimental data.