Impact dynamics of vibratory microprobe for microcoordinate measurement

Abstract

This article presents an impact dynamics analysis of the vibratory probe in a microcoordinate measuring machine. The chaotic behavior of the vibratory probe was identified when the driving frequency was changed. A multimode analysis was carried out to investigate the microprobe in both noncontact and contact states. An orthogonal mode transformation was used to maintain continuities when impact occurred. The analytical results indicated that mode coupling and mode coexistence suppressed subbifurcation and pulled down the impact period under particular driving frequencies. To achieve accurate identification of the microprobe in contact with microstructures, the frequency spectra of vibration signals at different contact states were compared. It was shown that the optimum driving frequency should be in the pull-down region. In this region, the dominant frequencies before and after the contact can be clearly separated, resulting in negligible background vibrations.