Mooring chain welding process fault diagnosis method based on symbolic representation

The invention discloses a fault diagnosis method for a mooring chain welding process based on symbolic representation, which comprises the following steps of: firstly, taking n original welding signals, respectively extracting a welding time sequence, a welding electrode position sequence, a welding current sequence and a welding state sequence of the signals to generate a new welding signal Si, and then segmenting the Si according to four welding stages, an output result is recorded as W * = [W0 W1 W2 W3], finally, W0, W1 and W2 are subjected to welding electrode position sequence processing and welding current sequence processing respectively, after processing, characters obtained after welding electrode position sequence processing and characters obtained after welding current sequence processing are spliced and put into clusters, the number of instances in all the clusters is calculated, and the number of instances in all the clusters is calculated. And marking the cluster with the instance number less th