基于LMS Test Lab模态分析软件及数据采集系统,对自制实验枪架上的某型高射机枪,采用多点激励单点响应法进行激振实验。通过PolyMAX模态参数识别方法,对测试数据进行模态分析,获得了该机枪结构的11阶模态固有频率、阻尼及其振型;得出机...基于LMS Test Lab模态分析软件及数据采集系统,对自制实验枪架上的某型高射机枪,采用多点激励单点响应法进行激振实验。通过PolyMAX模态参数识别方法,对测试数据进行模态分析,获得了该机枪结构的11阶模态固有频率、阻尼及其振型;得出机枪的变形主要表现为纵向和横向的振动特性;证明了自制实验枪架的刚度符合射击实验的标准。本研究得到的结果,为进一步指导该型高射机枪系统结构动态优化设计提供了理论依据。展开更多
Based on the good time-frequency localization of the wavelet packet modulation (WPM) system and the analysis of the muhitone (MT) interference, an improved WPM narrow band interference (NBI) rejection system usi...Based on the good time-frequency localization of the wavelet packet modulation (WPM) system and the analysis of the muhitone (MT) interference, an improved WPM narrow band interference (NBI) rejection system using an adaptive least mean square (LMS) algorithm is discussed in this paper. In the WPM interference rejection system, according to the structure of the wavelet packet tree (WFF) and the characteristic of the MT interference, the demodulated WPM signal which contains the interference component is filtered using an adaptive LMS filtering implementation. Theoretical analysis and simulation resuits show that the proposed method improves the bit error rate (BER) performance of the WPM system in the presence of MT interference.展开更多
文摘基于LMS Test Lab模态分析软件及数据采集系统,对自制实验枪架上的某型高射机枪,采用多点激励单点响应法进行激振实验。通过PolyMAX模态参数识别方法,对测试数据进行模态分析,获得了该机枪结构的11阶模态固有频率、阻尼及其振型;得出机枪的变形主要表现为纵向和横向的振动特性;证明了自制实验枪架的刚度符合射击实验的标准。本研究得到的结果,为进一步指导该型高射机枪系统结构动态优化设计提供了理论依据。
基金Supported by the National Natural Science Foundation of China (No. 60532030).
文摘Based on the good time-frequency localization of the wavelet packet modulation (WPM) system and the analysis of the muhitone (MT) interference, an improved WPM narrow band interference (NBI) rejection system using an adaptive least mean square (LMS) algorithm is discussed in this paper. In the WPM interference rejection system, according to the structure of the wavelet packet tree (WFF) and the characteristic of the MT interference, the demodulated WPM signal which contains the interference component is filtered using an adaptive LMS filtering implementation. Theoretical analysis and simulation resuits show that the proposed method improves the bit error rate (BER) performance of the WPM system in the presence of MT interference.