Impactor design for in-pipe impact-echo inspection method: A morphological analysis

Damaged sewer pipelines can cause many problems, like sinkholes in urban areas, and are very expensive to repair once broken. TISCALI, short for Tech-nological Innovation for Sewer Condition Assessment - Long-range Information, is a project which focuses on finding new ways of localizing damage in sewer pipelines before severe damage is caused. One of these methods is called the impact echo method. The impact method is often used in civil engineering to assess for example bridges, however is usually implemented manually. Manual implementation of impact echo in a sewer pipeline is not possible and for this rea-son, an impactor design will be designed which could be equipped on a crawler robot. The impactor will be designed according to the required impact time, impact energy, orientation and the need for a silent impactor. Some impactor designs have already been analysed by RaM, however non of these designs have satisfied all of the requirements. Part of this assignment is to do a morphological analysis. This analysis will provide an overview of possible designs and will help designing a mechanism that could overcome the shortcomings of the previous designs and could satisfy all the requirements.

The time that the impact takes should be of a required duration (40 - 80 µs) and should have sufficient impact energy (0.7 - 2.2 J). It should also avoid mul-tiple impacts and should be able to make impacts perpendicular to the surface in 360◦ of the inner surface of the pipeline. According to these requirements the impactor prototype will be designed and tested. In the meantime the mor-phological analysis will be performed.