Unmanned construction which includes teleoperation of construction machinery has been introduced after disasters in terms of operators’ safety. One of the most crucial problems in unmanned construction is that work efficiency is less than half compared with usual boarding operation owing mainly to lack of visual information. Environmental views from cameras installed at disaster sites are necessary for precise manipulation even if operators can watch a wide and three-dimensional cab view. Thus, we have investigated optimum and suitable pan and tilt angle of environmental views for precise manipulation including grasping and releasing by using a 1/20 scale model. Experimental analysis using an actual construction machinery is indispensable to apply results acquired by using a scale model for unmanned construction. Therefore, in the present work, we investigate optimum and suitable range of environmental views for precise operation by using an actual construction machinery. We focus on digging and releasing because construction machineries are usually used for digging gravel or sand, and release it to designated area including bed sections of dump trucks. The task of experiments using ZAXIS 35U was determined based on the model task of unmanned construction, including digging modeled to hook a target object and releasing it in the designated area. The results indicate that the optimum pan angle for digging is 60°, and suitable range of pan angle for digging is from 45° to 90°. Furthermore, the results suggest that the optimum tilt angle is 60°, and tilt angle between 45° and 90° affects a little on work efficiency.
