Designing arm for placement of an impact hammer in sewers

Underground sewer pipelines need maintenance from sources of damage, such as unstable ground support. To mitigate this the TISCALI project (Technology Innovation for Sewer Condition Assessment using Long-distance Information-systems) is creating an impactor sensor to look for early warning signs of collapse. We designed a 4 joint arm to place the impactor at a specific position and orientation in relation to the sewer wall. Then, we developed a control system for the arm to place the impactor while avoiding collision with the sewer wall. Finally, different systems were explored to mitigate recoil from the impactor, and we chose a non-backdrivable gear system. The armcan place the impactor in various pipe sizes and avoid collision with the sewer wall by using a path generation algorithm. Finally, recoil is limited to 0.2mm via the non-backdrivable gear system.