Intelligent tool fault diagnosis method

The invention relates to an intelligent tool fault diagnosis method. The intelligent tool fault diagnosis method comprises the steps that a PLC is arranged between the CNC end of a machine tool and the machine tool end; a plurality of tool vibration signals x(t) produced in the machine tool machining process are obtained by the PLC, all the collected tool vibration signals x(t) are processed, and tool characteristics are extracted; the correspondence relation between the tool vibration signals and a tool abrasion fault is built according to the obtained tool characteristic information so that the tool abrasion fault can be intelligently identified; each tool vibration signal is trained to obtain a hidden Markov model lambda; and the likelihood ratios are calculated through the trained hidden Markov models lambda, the sequences O of the tool vibration signals are input into all the trained hidden Markov models, the likelihood ratio of each tool vibration signal under the corresponding hidden Markov model is obtained, and then the tool state is identified. According to the intelligent tool fault diagnosis method, the characteristics of the machine tool and the characteristics of the vibration signals in the tool machining process are combined, the tool abrasion fault is automatically detected, and the tool abrasion state can be automatically identified.