During my trip in Japan, I had a chance to attend a bridge visual inspection demonstration using a robotic camera devise which is designed by Hitachi Industry & Control Solutions, Ltd for use at locations where close visual inspection is difficult, such as inspection of bridge soffits, or around bearings. Using pole units, it facilitates the process of positioning a camera at a height within visual range, conducting inspections, measurements, and acquiring video recordings. The photo provided below shows the devise mounted on an elevating type pole.
Figure 1. Bridge inspection robotic camera mounted on an elevating type pole unit.
Two pole units are available, the Suspending Type and the Elevating Type. By installing the base of the pole unit on a parapet, the suspending type can extend downwards to a maximum of 6.0m. In contrast, using a stand placed on the ground, the elevating type pole unit can extend a camera upwards to a maximum of 10.5m. The camera can be operated remotely from a tablet computer using wireless communications. On the video provided below, a site personnel explains how the system works.
Priorly, the company began development of robotic pole cameras for inspection of house roofs and similar applications in 1995, and they are now in wide spread use for bridge visual inspection activities.
The distance from the camera to the object is measured using a laser range finder mounted on the camera. Sizes on the surface of the object are assessed according to the distance measured, and an appropriately-scaled crack scale/ruler or L-square can be displayed on the operation tablet. When the engineer performing the inspection is unable to approach closer to the object, this function enables measurement of crack widths, lengths, and other damage. By adjusting the crack scale on the tablet, you can measure the actual width of the crack. In the below video technician measures the crack width using the system which is about 0.5mm thick.
I also attended some other technical visits during my trip in Japan which I will share in the following posts.