  Rehabilitating cast iron pipes through lining offers several advantages,
including increased durability, reduced water leaks, and minimal
disruption.This approach presents a cost effective and environmentally friendly
solution by sealing cracks and joints, extending the pipeline's lifespan, and
reducing water wastage, all while avoiding the need for trench excavation.
However, due to the relining process, branch connections are sealed and need to
be reestablished. To address the issue of rehabilitating small-diameter water
pipes, we have designed a modular robot capable of traversing and working
within 200 meter long, 100 mm diameter cast iron pipes. This robot is equipped
with perception functions to detect, locate, and characterize the branch
connections in cast iron pipes and relocate them after lining, as well as
machining functions. A first prototype of this system has been developed and
validated on an 8 meter long section, in a laboratory environment.
