转速平稳性对速率偏频激光IMU影响研究

Study on the Influence of Rate Stability on the Rate-biased Laser IMU

转位机构转动速率平稳性是影响速率偏频激光IMU初始对准精度的重要因素。从速率偏频激光IMU的工作原理和结构特点出发,理论分析了转位机构转动速率平稳性和初始对准航向角精度的关系,初始对准航向角误差和转位机构的转速相对误差呈三角函数关系,和转位机构的转速呈反比,转位机构的转速越大,转速不平稳导致的影响越小。提出了高精度速率偏频激光IMU的转速平稳性要求:要达到高精度的初始对准航向角,转位机构的转速相对误差需要控制在0.005以内,转速控制在18(°)/s以上。通过仿真分析和速率偏频激光IMU进行了试验验证,结果表明同等情况下,满足转速平稳性要求的速率偏频激光IMU的初始对准航向角误差带相对于不满足要求的减少了10",这对进一步提高速率偏频激光IMU的初始对准精度具有重要的理论和工程实践意义。

The rotation rate stability of the mechanism is a critical factor that affects the initial alignment accuracy of the rate-biased laser IMU.Starting from the working principle and structural characteristics of the rate-biased laser IMU,this paper theoretically analyzes the relationship between the rotation rate stability of the mechanism and the accuracy of the initial alignment heading angle.The relationship between the initial alignment heading angle error and the rotation speed relative error of the mechanism presents a trigonometric function,which is inversely proportional to the rotation speed of the mechanism.The greater the rotation speed of the mechanism,the less impact caused by the unstable rotation speed.In order to achieve high precision initial alignment heading angle,the rotation speed relative error of the mechanism should be controlled within 0.005,and the rotation speed should be controlled above 18(°)/s.The simulation analysis and the experimental verification of the rate-biased laser IMU show that the error band of the initial alignment course angle of the rate-biased laser IMU which meets the requirements of the speed stability is reduced by 10″compared with that which does not meet the requirements.It has important theoretical and engineering significance to improve the initial alignment accuracy of rate-biased laser IMU in the future.