相位式激光测距全相位谱分析鉴相算法  

ApFFT phase discrimination in phase-shift laser range finder

作　　者：王选钢[1,2] 缑宁祎[1,2] 张珂殊[1] 

机构地区：[1]中国科学院光电研究院,北京100094 [2]中国科学院研究生院,北京100049

出　　处：《信息与电子工程》2012年第6期725-729,共5页information and electronic engineering

基　　金：国家高技术研究发展计划(863)基金资助项目(2008AA121304)

摘　　要：为降低相位式激光测距的鉴相偏差,以余弦信号为对象深入研究全相位谱分析鉴相的性能。将余弦信号分解为指数形式进行频谱变换,得出负频率会引起谱分析鉴相偏差,但全相位谱分析的频谱泄漏远小于传统傅里叶变换(FFT)法,仿真时鉴相偏差降为后者的1‰。从信噪比增益角度研究窗函数对鉴相精确度的影响,分析表明,归一化频率偏移量绝对值小于0.3时,采用矩形窗的全相位谱分析鉴相方差最小,可达克拉美罗下限的1.3倍。实验结果表明,在测距系统中可忽略全相位谱分析鉴相的偏差,当信噪比为34 dB时,每秒百万次鉴相的精确度为3.3 mrad,测距精确度达1 mm,全相位谱分析适用于高精确度相位式激光测距。In order to reduce the offset of phase discrimination in phase-shift laser range finder,apFFT phase discrimination is studied based on cosine signal.Cosine signal is expressed in exponential form in spectrum transform.Analysis shows that phase discrimination offset is caused by the negative frequency.Spectrum leakage of apFFT is much smaller than that of traditional FFT,so its offset is only 1‰ of the latter in simulation.Window influence is also studied based on signal to noise ratio gain.When the normalization frequency offset is between-0.3 and 0.3,apFFT with rectangle window achieves the minimum variance.It can be 1.3 times of Cramer low limit.Experimental results indicate that the measurement offset of apFFT can be ignored.When the signal to noise ratio is 34 dB and measuring speed is up to 1 MHz,the measurement accuracy is 3.3 mrad and 1 mm respectively.ApFFT can be applied to high precision phase-shift laser range finder.

关 键 词：全相位FFT 鉴相 激光测距 相位式 

分 类 号：TN247[电子电信—物理电子学]