基于Hilbert-Huang变换的软性磨粒流抛光流道压力脉动分析

Pressure fluctuation analysis of softness abrasive flow based on Hilbert-Huang transform in finishing flow channel

针对软性磨粒流加工方法的加工效率和抛光均匀性等问题,提出了一种基于HHT的约束流道压力脉动监测方法。采用Hilbert-Huang变换(HHT)时频分析方法,对软性磨粒流约束流道内的压力脉动特性进行了研究,建立了约束流道内的湍流发展与压力脉动信号的内在联系,通过对压力脉动信号的监测,对流道内的湍流进行了调控;搭建了压力脉动测控实验平台,进行了磨粒流在线调控加工对比实验。研究结果表明:利用HHT变换方法分析获得的软性磨粒流抛光流道内压力脉动信号频谱信息,能充分体现流道入口磨粒流速度的频率和幅度等信息,通过监测压力脉动信号可以实现湍流调控;该方法不仅可以提高软性磨粒流加工的效率和抛光均匀性,还为软性磨粒流加工实现定向可控抛光提供了可能。

Aiming at the processing efficiency and polishing uniformity of the soft abrasive flow machining method,a pressure fluctuation monitoring method for constrained flow channel based on HHT was proposed.By using Hilbert-Huang transform time-frequency analysis method,the characteristics of pressure pulsation of soft abrasive flow in a flow channel were investigated.The internal relations between turbulent development and pressure fluctuation signals in the constrained channel were established.The turbulence in the channel was controlled by monitoring the pressure fluctuation signal.An experimental platform of pressure pulsation measurement and control was set up,and the on-line control experiment of abrasive flow was carried out for comparision.The results indicate that the spectrum information of pressure fluctuation signal in the polishing flow channel of the soft abrasive flow obtained by using the HHT transform method,can fully reflect the frequency and amplitude information of the abrasive flow velocity at channel entrance,by monitoring the pressure fluctuation signal can achieve turbulence control.The method can not only improve the efficiency and uniformity of the soft abrasive flow machining,but also provide the possibility for the soft abrasive flow machining to achieve directional controllable polishing.