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In recent years, the deterioration of many bridges built during the period of rapid economic growth has become a problem. As a solution of it, preventive measures such as visual inspections and repairs by humans have been taken, but these methods have problems in terms of cost and safety. If inspection by robots becomes possible, both of these problems will be improved and it is expected to contribute greatly to the maintenance and management of bridges. Therefore, a number of robots have been developed for the purpose of bridge inspection. The among such inspection robots, wire-driven robots, which have less risk of falling and can perform close proximity or contact inspection, are attracting attention. However, one of the problems with this type of robot is that it is difficult to place the wire under the bridge when there is a river or road underneath it, or when it is very high. Thus, in this study, a shooting device for shooting arrows with attached strings was developed to solve this problem. We then conducted a shooting experiment and confirmed that the device aimed at the target automatically and shot the arrow. In addition, we created a simulation model of an arrow with a string attached to it to obtain information such as the shooting angle of the arrow in advance. Then, the flight trajectory and horizontal flight distance of the arrows were compared between the actual and simulated data, and the consistency was confirmed.

A robotic fish is ideal for an ecological survey of underwater life, because underwater animals cannot easily notice the robot. However, when a robotic fish swings its body to swim, it makes a rolling motion due to movements of the center of gravity and this rolling motion has a bad influence on the coordinate calculation of the tracking target, therefore it is necessary to correct the image. The robot has FPGA (Field Programmable Gate Array) and it is suitable for real-time image processing because FPGA has excellent performance with its parallel processing. In this study, we create a program to calculate the roll angle of the robot by using the gyro and acceleration sensor mounted on the robot and to correct the image by rotating it by that angle. Then, we conduct an evaluation of this rotation correction method with rotation tester that reproduces the rolling motion of the robotic fish and determine synchronization timing of image data and angle data because the CMOS camera used for the robot adopts rolling shutter method. Furthermore, we investigate the effect on coordinate calculation by the fish robot with created program. We have confirmed that this robot can perform real-time correction of rotated image and reduce the influence on the coordinate calculation of the target.

In recent years, the deterioration of infrastructure facilities such as bridges has become a problem. Precautionary measures such as visual inspections and repair by humans are in place as countermeasures for aging, but there are problems with cost and safety in such inspections. If inspection by robots becomes possible, both will be improved, which will greatly contribute to the maintenance of infrastructure facilities. In this paper, we propose a localizational position specifying system for a robot supporting bridge inspection of the moving robot under the bridge to support inspection of the bridge. Since the robot must travel on the steel structures at the bottom of the bridge, strong permanent magnets need to be installed on the edge parts in the wheels. Also, it is not possible to receive the coordinate information from the satellite as it travels at the bottom of the bridge. Therefore, a 1-dimensional low-cost LiDAR sensor and a stepping motor are used to implement as a planar LiDAR sensor which rotates 360 degrees, specify the position of the current robot by obtaining distance and direction data from fixed feature points. The localizational position specification through the planar LiDAR are examined by the experiment. As a result, it was possible to estimate the localizational position of the robot.

Many structures such as bridges, buildings, tunnels and dams had been constructed during the high economic growth period in Japan. The deterioration of these structures has become a big social problem. The maintenance method which finds the minor damages on the structures is important for the life extension of many structures before the progress of deterioration advances. When the inspections become frequent, the huge cost is needed. Robots are said to be useful for the management and maintenance of many old structures because the conventional method will intensify the strains on economy. In this study, we have created a flying robot HORNET with tilt-rotors and two wheels. HORNET can move on a vertical wall keeping a constant distance between the robot and a wall. Then, it is very easy and safe to control the robot manually. In addition, the electric power consumption of HORNET can be smaller than hovering robot like drones because HORNET can hang on wall with claws of the wheels. We have examined the effects of the state of wall surface and the tilt angle of rotor surface on the electric power consumption of HORNET. According to the experimental results, it has been confirmed that the electric power consumption is reduced when the state of wall surface is rougher and the tilt angle of rotors is more parallel to the ground. It is possible to become a practicable wall inspection robot by adding the improvement to HORNET.

Many infrastructures such as bridges and tunnels had been constructed in various parts of Japan during the high economic growth period. They need periodic inspection because they are aging. Inspecting them by inspector is both costly and time-consuming. There is a strong demand for practical bridge inspection robots to reduce the costs and times. The inspection robot running autonomously on the bridge needs to determine moving route and to estimate self-position. The robot must have a three dimensional map of the bridge to take these actions. This paper proposes a method of making a three-dimensional occupancy grid map of the large scale infrastructure where the inspector cannot go easily such as an underside of the bridge. A bridge inspection robot equipped with magnets had been developed in present study. We attached a measuring device which consists of a small 2D laser range finder and a servo motor. Experiments were conducted to make the 3D map by using the robot. The robot climbed to target position on the wall without falling although it was equipped with the measuring device which is heavy. Moreover, the robot can make the 3D occupancy grid map and the map can be useful to inspect bridges.