Abstract: Aiming at the problem that mathematical morphology structuring element is unable to adjust its length dynamically, a morphological filtering method using nonlinear quantum bit integrating quantum theory is presented, to enhance mechanical vibration signal processing effect of morphology. Firstly the feasibility of combination between mechanical signal and quantum theory is analyzed. Based on the analysis, the quantum expressions of crest and trough in mechanical vibration signal are presented. Then combining both maximum and minimum of vibration signal, an expression of nonlinear quantum bit is proposed after mathematical analysis, which is used to depict the instantaneous state of vibration signal. The next according to the relevance in the neighbourhood of mechanical vibration signal, a quantum system with multiple quantum bits for mechanical vibration signals is proposed after local characteristics of vibration signals are analyzed. Based on the quantum expressions of crest and trough in mechanical vibration signal, a structuring element length shrinkadge operator using quantum probability is proposed for mechanical vibration signals in the framework of quantum system with multiple quantum bits. Based on the length shrinkadge operator, the length of structuring element achieves adaptive adjustment. An example of bearing fault diagnosis is given and gets a good result which indicates that this method is more effective in extracting fault pulse information than that using a conventional method.

Key words: dynamic, mathematical morphology, quantum theory, structuring element