Control of position and attitude of the tethered X4-Flyer

In Japan, aging of infrastructures, such as roads, bridges, and water and sewer services, etc. poses a problem, and it is required to extend the life-span of such infrastructures by maintenance. Among infrastructures, especially bridges are periodically inspected by short-range visual observations, which check the damage and deterioration of the surface. The short-range visual observation by a human is widely used to evaluate the degree of damage and understand the damage status of concrete structures such as bridges, because it is possible to check the deterioration and damage of the surface cracks, etc. However, since there are some cases where the short-range visual observation is difficult, an alternative method is required so as to replace the short-range visual observation with it. So, “X4-Flyer” is very attractive because of realizing a movement at high altitude easily. It needs to control the position and attitude of the X4-Flyer, if it is used for the inspection of infrastructures, such as bridges etc. Although the position control using the GPS is common, it is difficult to use such a control method in environments, such as a tunnel or under a bridge, where the GPS signal does not reach to or is weak. In addition, the manual operation by a joystick etc. is difficult when affected by disturbances such as wind etc. So, we propose a method for controlling an X4-Flyer using a tether, not relying on the operation of a joystick or the use of GPS. In this study, it aims at developing the X4-Flyer with tether to replace the short-range visual observation of infrastructure. In this paper, we describe measuring and controlling the position of a tethered X4-Flyer.