关键词: 碰撞声, 希尔伯特-黄变换（HHT）方法, 反向传播（BP）神经网络

Abstract: This paper uses HHT method to analyze the impact acoustic signal of un-damaged kernels, IDK and moldy damaged kernels, extracts five characteristic features from three types of wheat kernels, and classifies the wheat kernels with BP neural network, gets a good recognition result in the end. The experimental result shows that each type of wheat kernels is much different from other types in frequency domain. The research provides a feasible method for the wheat kernels identification and separation.

Key words: impact acoustic signal, Hilbert-Huang Transform（HHT）, Back Propagation（BP） neural network