中文摘要：

为确定铝合金脉冲MIG（P-MIG）焊过程稳定性，根据近似熵的理论，对铝合金脉冲MIG焊中的电压信号进行近似熵分析，通过对不同焊接速度、送丝速度与占空比的焊接规范参数下的电压信号近似熵的计算分析，证明利用电弧电压信号的近似熵分析可以衡量铝合金脉冲MIG焊接过程稳定性。初步建立了铝合金脉冲MIG焊过程稳定性评价体系：平均近似熵值小，其焊接过程比较稳定；平均近似熵值大，其焊接过程不稳定。

英文摘要：

In order to evaluate the stability of the process of aluminum alloy pulsed MIG welding, an approximate entropy analysis has been done on voltage signal in the process of aluminum alloy pulsed MIG welding. The calculation and comparison of the approximate entropy on voltage signal under different welding parameters, such as weelding speeds, wire feed speeds , duty cycle and so on, shows that the approximate entropy of voltage can reflect the stability of the process of aluminum alloy pulsed MIG welding. The results show that the smaller the average value of approximate entropy, the more stable the welding process will be. Otherwise, the welding process is unstable while the average value is bigger.