Evolution Mechanism Analysis and Stability Evaluation of Machining Process Based on Minimum Entropy Space State

In intelligent manufacturing, products' high precision and reliability put forward higher requirements for machining process stability. The machining process's new stability evaluation method is proposed based on the minimum entropy space state (MESS). Four metrics, including entropy, variation of entropy, minimum entropy space state, and hyper entropy, are used to evaluate the machining process. First, the definitions of the four metrics are given, and the relationships between the four metrics are concluded. Then the calculation methods of the four metrics are given. Time-domain features of machining process signals are also extracted. The evolution mechanism of the machining process is expressed through the perspective of entropy. Then the values of the four metrics are used to evaluate the machining process. Extensive empirical evaluations on the turning process of bearing seats validate the applicability and practicability of the proposed method.