• CN: 11-2187/TH
  • ISSN: 0577-6686

›› 2013, Vol. 49 ›› Issue (18): 184-189.

• Article • Previous Articles     Next Articles

High Pressure Water Jet Cutting Sound Feature Extraction and Nozzle Traverse Speed Control

ZHANG Jun;ZHAO Dean;LI Xuefeng;XU Lilong   

  1. Electrical and Information Engineering College, Jiangsu University CNC Machine Tool Research Institute of Jiangsu Province
  • Published:2013-09-20

Abstract: The key factor to influence the quality and efficiency of water jet cutting is the traverse speed of ultra-high pressure water jet nozzle. The major research to achieve flexible water jet cutting is about how to choose the optimal nozzle traverse speed to different workpieces. When the ultra-high pressure water jet cuts different geometric objects made of various materials, the reflected sound feature are different, which mainly consist of the reflected sound energy and cutting sound time. As the workpieces thickness increases, both the reflected sound energy and cutting time will raise at the same time. Indirectly, complexity and difficulty of workpieces cutting are indicated by the reflected sound feature, which provides convenience for optimizing nozzle traverse speed. In this paper, a computer operated acquisition system for water jet cutting sound is designed. In which the reflected cutting sound signal, mainly including background noises and the reflected sound signal of workpieces cutting, is based on that the second generation wavelet transform and Teager energy operator are applied organically conjunctively in processing cutting sound signal for denoising background noises, and to extract sound features which reflect the quality of cutting different workpieces. Moreover, the nonlinear model is established between the cutting nozzle traverse speed and the sound feature based on least squares support vector machine, reduce artificial experience of trial and error, and enhance production efficiency. In several field tests, the feasibility and validity of the proposed scheme are verified and confirmed.

Key words: High pressure water jet, Nozzle traverse speed, Sound feature, Support vector machine, Wavelet analysis

CLC Number: