Pipeline Inspection Gauges have been traditionally used to perform analysis and maintenance of the pipe internal section. The tool is propelled by the flowing fluid and its velocity can be controlled by regulating the differential pressure between the pipe terminals. Modern PIGs bring on-board sophisticate systems, able to measure the wall corrosion, to identify jet noise at small holes, to georeference automatically its position.
SAIPEM is developing innovative PIGs for the mitigation of risks during pipe laying operations: these new tools follow the pipe lying vessel while transmitting in real time information on the pipe status. The modern tools require a very accurate positioning and velocity control, that is achieved through direct actions of the PIG and fine tuning of the fluid flow conditions. In this framework it is fundamental to develop simulators of the whole system, integrating the dynamic variables of the motion with the mechanical/electrical limits of the PIG instruments, calibrating the numerical models with real data, deriving feasible and reliable control policies. We present our current achievements and experience in all these topics.