为了从复杂的非平振动信号中追踪直升机的传动系统轴转速信息,开发了一种改进的广义解调变换方法。首先,利用广义解调变换对目标信号进行移频,移频后目标分量将由非平稳转换为近似平稳;其次,基于频谱细化的短时傅里叶变换(short time Fo...为了从复杂的非平振动信号中追踪直升机的传动系统轴转速信息,开发了一种改进的广义解调变换方法。首先,利用广义解调变换对目标信号进行移频,移频后目标分量将由非平稳转换为近似平稳;其次,基于频谱细化的短时傅里叶变换(short time Fourier transform,简称STFT)方法计算得到解调信号时频图;然后,估计信号的瞬时频率,利用迭代计算提升频率估计精度;最后,基于估计的转速信息开展同步分析,提高传动系统齿轮故障振动的信噪比。仿真分析和实测分析结果表明:所提出方法估计的轴速度信息具有较高的精度,满足基于速度信息开展同步分析的需求;利用估计的速度开展同步分析可有效提高信噪比,增强阶次谱上的故障特征,便于准确提取齿轮故障特征。展开更多
The Paper introduces an IF software radio receiver development Platform based on high-speed monolithic A/D Converter AD6640, Progranunable Digital Down-converter AD6620 and high-speed DSP chip TMSC320C6701. The implem...The Paper introduces an IF software radio receiver development Platform based on high-speed monolithic A/D Converter AD6640, Progranunable Digital Down-converter AD6620 and high-speed DSP chip TMSC320C6701. The implementation method is described as well as AD6620 parameter setting analysis. It also presents a flow chart of the on-line programming with the help of PC. The algorithm for demodulation AM signal is discussed.展开更多
文摘为了从复杂的非平振动信号中追踪直升机的传动系统轴转速信息,开发了一种改进的广义解调变换方法。首先,利用广义解调变换对目标信号进行移频,移频后目标分量将由非平稳转换为近似平稳;其次,基于频谱细化的短时傅里叶变换(short time Fourier transform,简称STFT)方法计算得到解调信号时频图;然后,估计信号的瞬时频率,利用迭代计算提升频率估计精度;最后,基于估计的转速信息开展同步分析,提高传动系统齿轮故障振动的信噪比。仿真分析和实测分析结果表明:所提出方法估计的轴速度信息具有较高的精度,满足基于速度信息开展同步分析的需求;利用估计的速度开展同步分析可有效提高信噪比,增强阶次谱上的故障特征,便于准确提取齿轮故障特征。
文摘The Paper introduces an IF software radio receiver development Platform based on high-speed monolithic A/D Converter AD6640, Progranunable Digital Down-converter AD6620 and high-speed DSP chip TMSC320C6701. The implementation method is described as well as AD6620 parameter setting analysis. It also presents a flow chart of the on-line programming with the help of PC. The algorithm for demodulation AM signal is discussed.
