|
|
|
| A Measurement Method of Frequency Response Characteristics Test Based on Chirp Signal at Low SNR |
| WEI Lie-jiang1, LI Xu-fang1, WANG Lin1, DONG Wan-yu1, MENG Li2 |
1.School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China;
2.Gansu Institute of Metrology, Lanzhou, Gansu 730070, China |
|
|
|
|
Abstract A method using band-pass filter and wavelet packet transform to pre-treat signal and then using FFT analysis and treatment to get frequency response diagrams is described. This method is better to solve the problems that frequency characteristic test of the system is under low SNR, and reduce hardware requirements of acquisition system in the test. The research show that when SNR is very low and even negative 20 dB value, the amplitude-frequency characteristic that accuracy is not less than 1dB and phase frequency response curve that accuracy is not less than 3°can be obtained for frequency bands that is below the cutoff frequency, which fully meet the system performance evaluation and controller design application requirements.
|
|
|
|
|
|
［1］ 陈平,裘丽华.液压伺服系统测试的谱分析法研究［J］.机床与液压,2002,(1):101-141.
［2］ 叶齐鑫,侯国屏,赵伟.虚拟仪器环境下的频率特性测试方法［J］.电测与仪器,2005,22(2):1-3.
［3］ 张群英,杨雪贤,何佩琨,等.A/D量化误差对脉冲压缩结果的影响［J］.现代雷达,2002,42(6):64-68.
［4］ 范显峰,姜兴渭.基于小波包变换的信号去噪方法研究［J］.哈尔滨工业大学学报,2003,35(7):809-811.
［5］ 黄宜军,汪金友.小波分析在微弱信号测量中的应用研究［J］.计量学报,2007,28(2):163-166.
［6］ 王玥萌.频率特性综合测试系统的研究和设计［D］.哈尔滨:哈尔滨工业大学,2012.
［7］ Wang Q G, Hang C C, Bi Q. Process Frequency Response Estimation from Relay Feedback ［J］.Control Engineering Practice,1997,5(9): 1293- 1302. |
|
|
|
2014, Vol. 35 
