In chapter 3, existing time and frequency analysis methods are used for signal processing to find the characteristic that can indicate casting states, in the end of the chapter, wavelet package analysis method for characteristic acquisition is put forward and testified by results. 第三章应用常见的信号时域和频域分析方法对钢水浇铸振动信号进行分析,来寻找能够表征钢水浇注状态的特征参数,最后提出用小波包分析方法获取信号特征。