反馈延迟对光纤陀螺振动误差特性的影响

Impact on vibration error characteristics of FOG with feedback delay

振动环境导致光纤陀螺引入较大的扰动。由于非线性因素,陀螺跟踪扰动的能力严重影响着其误差特性,而反馈延迟的存在使得跟踪性能变得更加复杂。因此,分析反馈延迟对于解决陀螺振动问题极其重要。首先,分析了非线性因素作用时不同反馈延迟对陀螺闭环跟踪能力和扰动稳定性的影响;然后在线性控制模型的基础上加入陀螺非线性环节,保证稳定裕度不变,仿真分析了不同反馈延迟下陀螺的跟踪性能以及输出。仿真及实验结果表明,减小反馈延迟,提高系统的跟踪扰动能力,可以减小非线性误差,改善振动环境下陀螺的输出性能。

Large disturbance is introduced into fiber optic gyroscope under vibration environment. And the error characteristics for FOG are severely affected with the ability of tracking disturbance as the existence of non-linear factors, which becomes more complicated as the result of the additional feedback delay. Therefore, it is important for solving vibration problem to analyze the feedback delay. Firstly, impacts on the closed-loop tracking ability and the stability against disturbance of FOG with different feedback delay were analyzed with the non-linear factors. Then, the non-linear element was considered based on the linear control model, and the outputs of FOG with different feedback delay were obtained and the tracking performance was analyzed by simulation as keeping the same stability margin. The simulation and final experiment show that the bias of FOG will be brought into a large offset under vibration with a poor tracking performance. Thus, it is important to solve the vibration problem of FOG by improving the closed-loop tracking ability with a small feedback delay.