光学 精密工程, 2019, 27 (2): 279, 网络出版: 2019-04-02
偏振调制测距系统频率漂移误差及其补偿
Frequency drift error and its compensation in polarization modulation range-finding system
摘要
偏振调制测距方法中, 频率测量的稳定性是影响测距精度的关键因素。为提高偏振调制测距系统中频率测量精度, 提出一种双向扫频频率测量方法。分析了偏振调制测距原理及测频精度与测距精度的关系, 探讨了频率漂移量的影响因素和频率漂移规律, 证明调制深度和热致附加相位差是影响频率漂移的重要因素。利用正向扫频和反向扫频时频率漂移方向相反的特点, 提出频率漂移误差补偿方法, 可在低调制深度条件下补偿热致附加相位差引起的频率漂移。对距离为15.23 m的目标进行测量, 频率测量标准差从3.822 9×104 Hz减小到5.807 5×103 Hz, 测距误差从7.513 7 mm减小到0.866 7 mm, 验证了该方法的有效性。
Abstract
To improve the accuracy of frequency measurement in a polarization modulation range-finding system, a method based on dual-directional frequency sweep was proposed. First, the principle of the ranging method and the relationship between frequency and ranging stability were analyzed. Then, factors influencing frequency drift, as well as the changing law of drift in the system, were discussed, and it was proved that modulation depth and thermally induced additional phase delay are important factors affecting frequency drift. Accordingly, a compensation method was proposed to compensate for the frequency drift caused by additional thermal phase delay, which can be realized with low modulation depth. Experimental results show that, for the target at 15.23 m, the standard deviation of frequency measurement decreased from 3.822 9×104 Hz to 5.807 5×103 Hz, the ranging error decreased from 7.513 7 mm to 0.866 7 mm, and the validity of the method was verified.
高书苑, 黎尧, 纪荣祎, 石俊凯, 胡哲文, 周维虎. 偏振调制测距系统频率漂移误差及其补偿[J]. 光学 精密工程, 2019, 27(2): 279. GAO Shu-yuan, LI Yao, JI Rong-yi, SHI Jun-kai, HU Zhe-wen, ZHOU Wei-hu. Frequency drift error and its compensation in polarization modulation range-finding system[J]. Optics and Precision Engineering, 2019, 27(2): 279.