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TANG Xinglun
Department of Precision
Instrument & Mechanics,
Tsinghua University,
Beijing 100084, China
ZHANG Zhijing
School of Mechanical & Vehicle
Engineering,
Beijing Institute of Technology,
Beijing 100084, China
ZHOU Zhaoying
Department of Precision
Instrument & Mechanics,
Tsinghua University,
Beijing 100084, China
YANG Xiaodong
Equipment & Energy Department,
Guizhou Branch of Aluminum Co., Ltd., Guiyang 550014, China |
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AUTOREGRESSIVE
MODEL AND POWER SPECTRUM CHARACTERISTICS OF CURRENT SIGNAL IN
HIGH FREQUENCY GROUP PULSE MICRO- ELECTROCHEMICAL MACHINING*
Abstract:
The identification of the inter-electrode gap size in the high frequency group pulse micro-electrochemical machining (HGPECM) is mainly discussed. The auto-regressive(AR) model of group pulse current flowing across the cathode and the anode are created under different situations with different processing parameters and inter-electrode gap size. The AR model based on the current signals indicates that the order of the AR model is obviously different relating to the different processing conditions and the inter-electrode gap size; Moreover, it is different about the stability of the dynamic system, i.e. the white noise response of the Green’s function of the dynamic system is diverse. In addition, power spectrum method is used in the analysis of the dynamic time series about the current signals with different inter-electrode gap size, the results show that there exists a strongest power spectrum peak, characteristic power spectrum(CPS), to the current signals related to the different inter-electrode gap size in the range of 0~5 kHz. Therefore, the CPS of current signals can implement the identification of the inter-electrode gap.
Key words:
Electrochemical machining Inter-electrode gap Autoregressive(AR) model Power spectrum
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