The deterioration of the infrastructure such as buildings is a serious problem nowadays. The new system which can rapidly inspect a large surface area of the external wall is desired. In general, the inspection of the external wall is carried out by tapping with a hammer in the hand of a professional engineer. The engineer has to use a gondola at high place to inspect the external wall of a tall building. Therefore it is very dangerous and it takes much time to accomplish the work. In this report, the impact acoustic wall inspection machine which has a function of hammer tapping is introduced. We consider the way how to hang and swing the inspection machine with a wire from the roof of the building. Then, we propose a control scheme to generate and continue the pendular motion of the inspection machine.