四频差动激光陀螺自适应程长控制技术

为了减小四频差动激光陀螺(FMDLG)对外界干扰的敏感性,设计了自适应程长控制系统使之工作于最佳工作点。对FMDLG的程长进行小抖动正弦调制,利用相敏检波技术从光强中提取调制信号的基波和二次谐波幅度。上述两个信号和光强一起用来实现自适应程长控制,它包括自动增益控制、自动调制幅度控制和程长控制3个环路。实验表明,自适应控制可有效消除光学和电子元件参量以及光强变化对控制系统的影响,而且可使FMDLG稳定地工作在最佳工作点上,从而降低其磁灵敏度。

Adaptive Path Length Control Technique for Four-Mode Differential Laser Gyro

In order to reduce the sensitivity to external disturbance of four-mode differential laser gyro (FMDLG), an adaptive path length control system is designed to make the FMDLG run at optimal operating point. Path length of the FMDLG is modulated with small amplitude sine wave. The amplitudes of 1st and 2nd harmonic signals in light intensity are extracted with phase sense detector technique. The above two signals along with light intensity are used to realize adaptive path length control, which consist of automatic gain control, automatic modulation control and path length control. Experimental results show that adaptive path length control reduces the influence of variations of optical and electronic components parameters as well as light intensity on control system. It is important that it can make the FMDLG run at optimal operating point steadily. The adaptive path length control helps to reduce FMDLG′s sensitivity to magnetic field.