An Automatic Validation System for Interferometry Density Measurements in the ENEA-FTU Tokamak Based on Soft- Computing

In this paper, an automatic sensor validation strategy for the measurements of plasma line density in the ENEA-FTU tokamak is presented. Density measurements are performed by a 5-channel DCN interferometer. The approach proposed is based on the design of a neural model of the observed system., i.e. a model able to emulate the behavior of a fault-free sensor and of a two-stage fuzzy system able to detect the occurence of a fault by using a set of suitable indicators. The fault diagnosis and classification is also accomplished. The validation strategy has been implemented and embedded in an interactive software tool installed at FTU. Statistics concerning the rate of fault detection agree with the rate of uncertainty usually achieved in the post-pulse manual validation.