The invention discloses a milling chatter diagnosis method based on multi-step differential entropy, and belongs to the technical field of
mechanical system fault diagnos.The method comprises the operation steps that the type and the installation position of a sensor are selected, and chatter diagnosis parameters are determined; acquiring synchronous vibration data X; the difference
step number mu is set to be equal to 1, the embedded dimension is m, the time
delay is tau, and the following calculation is repeated until the difference
step number mu is larger than the
maximum difference step number mu T; reconstructing a
phase space P [mu] of the synchronous vibration data X;
processing the
phase space P [mu] according to a difference rule to obtain a
phase space P '[mu]; calculating the
cosine similarity between each two adjacent rows of data in the phase space P 'mu; the interval [-1, 1] is divided into epsilon intervals at equal intervals, probability distribution of the obtained
cosine similarity in each interval is counted, and mu step difference entropy is calculated; making the difference step number mu = mu + 1 and the embedded dimension m = m0 + (mu-1), and returning to continue to calculate the mu step difference entropy; determining a
flutter type according to a
flutter diagnosis criterion; the method can effectively overcome the inherent defects of traditional entropy, remarkably improve the accuracy, timeliness and reliability of
flutter diagnosis, provide
solid technical support for flutter research and recognition in the
machining process, practically improve the
machining efficiency, reduce the influence of flutter on the
machining quality and reduce the production cost. Besides, the method is highly in line with the trend of intelligent development of the manufacturing industry, has wide application prospects, and is expected to promote
technical innovation and progress of the machining industry.