捷联惯导系统内水平阻尼网络设计

Damp Network Design of Horizontal Loop in Strapdown Inertial Navigation System

针对捷联惯导系统水平回路的控制系统模型和误差特性,研究系统内水平阻尼网络的设计方法。通过建立单通道水平回路的控制系统模型,分析了系统的稳定性和频率特性。针对幅频特性曲线不同频段表征系统的不同性能,研究了一种基于对数幅频特性曲线的阻尼网络设计方法。通过将系统期望的调节时间、超调量等时域指标转化为频域参数,设计系统期望的开环幅频特性,从而确定捷联惯导系统水平阻尼网络参数。利用本文阻尼网络进行了捷联惯导系统数字仿真和海上试验。仿真条件下系统姿态误差的舒拉周期振荡成分经1～2个舒拉周期后衰减至零,系统位置误差由4 nmile/24 h提高至1.5 nmile/24 h.系统海上阻尼试验结果表明系统姿态精度提高1个数量级,位置精度提高1倍。与试探法设计的网络相比,本文网络具有一致的稳态性和更小的超调量和调节时间。

The damp network design for strapdown inertial navigation system（SINS） was studied according to the control model and error characteristic of SINS horizontal loop.The stability and frequency characteristic of the system was analyzed on the basis of the control model.As the logarithmic magnitude curve of the horizontal loop model on different frequency bands reflected different performance of the system,a design method based on the expected curve was proposed.In the method,the time-domain performance indexes were transformed to frequency parameters,by which the expected logarithmic magnitude curve was plotted.Finally the damp network parameters were obtained.Digital simulation and test on sea for SINS were completed.In the simulation the Schuler oscillation in attitude error was damped to zero and the position error was increased to 1.5 nmile/24 h from 4 nmile/24 h,and in the test on sea the attitude accuracy improved by 1 order and the position accuracy improved by 1 time when the damp network was cascaded into the SINS.Compared with the network designed by the tentative method,this damp network has the same steady-state performances and less overshoot and settling time.