基于CD4046的激光陀螺机械抖动控制技术

Mechanical dither control technology of laser gyro based on CD4046

温度变化会引起激光陀螺抖动谐振频率的改变,进而引起激光陀螺机械抖动偏频的不稳定。为此,提出了一种新的基于CD4046锁相环的激光陀螺机械抖动控制系统,并对锁相环工作原理进行分析,在分析锁相环误差传递函数的基础上,给出了CD4046锁相环的跟踪精度和同步范围等设计指标。为消除机械抖动偏频带来的动态锁区误差,采用具有随机噪声特性的m序列对机械抖动信号加噪。实验结果表明,采用锁相环跟踪抖动机构谐振频率,在变温环境下可保证陀螺不失锁且频率的跟踪误差小于0.015 Hz,陀螺精度相比于自激振荡机械抖动控制系统提升了20%。

The dither resonance frequency of laser gyro will be changed due to the change of temperature,and the dither offset frequency of laser gyro will be unstable.In this paper,a new mechanical dither control system for laser gyro based on CD4046 PLL is presented,and the working principle of the PLL is analyzed.Based on the error transfer function analysis of the PLL,the tracking accuracy and synchronization range of the CD4046 PLL are given.In order to eliminate the dynamic locking error caused by the mechanical dither offset frequency,the random noise m sequence is used to add noise to the mechanical dither signal.The experimental results show that the Phase⁃Locked Loop(PLL)is adopted to track the resonant frequency of the dither mechanism,and the tracking error of the gyro is less than 0.015 Hz in the variable temperature environment.The precision of the laser gyro is improved by 20%compared with that of the self⁃excited oscillating mechanical dither control system.