Feature Extraction Of Ceramic Cracking Faults Of Ultrasonic Motor Based On Morphological Spectrum And LCD

Ultrasonic motor is a new type of motor used in aerospace equipment.Its peculiar operation mode and performance that ordinary electromagnetic motor have not possessed make the motor play an irreplaceable role in the complex space environment.Its performance will directly affect the entire system.Piezoelectric ceramic cracking is the key factor to determine the service life of ultrasonic motor.A method used to simulate ceramic cracking in the stator of traveling wave ultrasonic motor is proposed.Firstly,the rationality of stator modeling was verified by the particle movement tracks via dynamic analysis.Secondly,the fault degree of ceramic was simulated by different crack length,then the variation of monitor electrode voltage with crack dimension is analyzed.Ultrasonic motors inevitably suffer certain disturbances in their actual work,aiming at the influence of noise in the mechanical coupling process of the stator and rotor of ultrasonic motor,this paper proposes a method to reconstruct fault signal based on the solitary voltage via the morphological spectrum information under multi-scale.Through the local characteristic-scale decomposition(LCD)of restructured signal,entropy of energy spectrum can be calculated,which can be reflected as the fault feature of piezoelectric ceramics cracking in ultrasonic motor.Meanwhile,the anti-interference performance of the fault feature is analyzed under different simulated noise environments.Finally,the monitor electrode voltage data of fault motor with ceramic crack was collected,the analysis has shown that the simulation results are in good agreement with the actual measurement,and verify the feasibility and effectiveness of this method in the fault features extraction of piezoelectric ceramic cracking of ultrasonic motor.