Flash butt welding quality evaluation method based on welding process characteristics

The invention discloses a flash butt welding quality evaluation method based on welding process characteristics, which comprises the following steps of: (1) performing signal acquisition on a welding process through a current sensor, a displacement sensor and an upsetting force sensor, determining a welding signal parameter sequence, and acquiring a welding state sequence through a welding control system; (2) performing feature extraction on the welding parameter sequence obtained in the step (1) to obtain a welding parameter feature value; (3) classifying the acquired features; and (4) establishing a two-stage index quality evaluation model, and evaluating the welding quality. According to the method, typical features in different welding stages are extracted, the welding quality is evaluated from multiple aspects, and the accuracy and scientificity of evaluation are guaranteed. The two-stage index evaluation model solves the problem that the flash butt welding process is influenced by mutual coupling of mul