Full-state frequency tracking algorithm of ultrasonic welding
Ultrasonic metal welding loads are heavy and vary drastically,which can easily lead to non-resistive frequency state in the transducer and supply frequency mis-tracking.This paper proposes an full-state fre-quency tracking algorithm based on the Mason equivalent model that can simultaneously calculate the reso-nant and anti-resonant frequencies to avoid mis-tracking.When the transducer has resonant frequency and anti-resonant frequency,the target frequency is calculated by using three different frequencies and their corre-sponding phase differences in welding process;when transducer is in non-resistive frequency state,the tracking target is changed to the point with the minimum phase difference,thus achieving full-state frequency tracking.The algorithm was simulated by simulation software and it was concluded that the algorithm can avoid the frequency mis-tracking phenomenon.The welding test results show that the frequency tracking of resonant frequency and anti-resonant frequency can be easily achieved,and the welding process is smooth when the transducer is in the non-resistive frequency state.
Frequency trackingFull-state controlMis-trackingUltrasonic generatorUltrasonic metal weld-ing
NETL
NSTL
万方数据
维普
