摘要
结合正弦扫频信号相位函数的微分方程的特点,研究一种新的驱动信号产生方法,此方法具有较高的输出精度,并对外差操作具有良好的适应性。外差操作可将响应信号频谱从当前扫描频率平移到直流分量,该直流分量描述了响应信号的均方根或者幅度的实部与虚部信息,直流中频检测器通过选择适当的低通滤波器释放出该直流分量,从而实现响应信号的跟踪滤波和均方根处理。实践证明该信号处理技术特别适用于正弦扫频信号的时变谱分析。
The objective of a swept-sine test is to subject the device under test （DUT） to a low-distortion sinusoidal vibration environment of smoothly changing frequency and amplitude. The testing also requires that the controller be able to measure the response of this type of excitation. The output swept-sine wave generation has been accomplished using the governing differential equation for the phase function associated with the linear sweep and the logarithmic sweep mode. This method has increased the accuracy of the output signal and has the suitability of heterodyne generation. The purpose of the heterodyne is to translate the response signal spectrum about 0-Hz. The term at DC either represents the root mean square （RMS） or the real and imaginary components of its AC amplitude. The 0-Hz intermediate frequency detector implements tracking filter and root mean square processing by a low-pass filter that extracts the DC component. The engineering practice proves that the technique of digital signal processing can be applied to time-variable spectral analysis of the swept-sine wave.
出处
《振动工程学报》
EI
CSCD
北大核心
2008年第3期309-313,共5页
Journal of Vibration Engineering
基金
教育部新世纪优秀人才支持计划(NCET-04-0325)
关键词
正弦扫频
振动控制
跟踪滤波
均方根
外差发生器
swept-sine
vibration control
tracking filter
root mean square
heterodyne generation
