抄録
It needs a lot of workload, skill and cost to inspect and maintain bridges. Especially, in a small city, it is very difficult to do this work regularly because of a lack of fund and man power. This is the reason why so many old bridges will be damages and out of use in the near future. In this paper, we proposed the method to inspect a crack in a bridge by using camera and solving inverse problem. First, deflection along a bridge was precisely measured by camera and then stiffness of each element of a bridge was estimated by solving inverse problem with regulation technique. Finally, we showed that deflection was measured with accuracy of 0.5mm and stiffness was estimated with high accuracy.