基于BiLSTM的惯导中断数据修复方法及其性能分析

A BiLSTM-Based Method for Inertial Navigation Data Interruption Reconstruction and Its Performance Analysis

  • 摘要: 惯性测量单元(inertial measurement unit,IMU)数据中断会显著降低组合导航系统的定位定姿精度。IMU观测数据作为高频时序信号,相邻历元间具有强相关性,导致复杂运动条件下传统时间序列预测方法难以对其进行精准建模。为此,提出一种基于双向长短期记忆网络(bidirectional long short term memory,BiLSTM)的时间序列预测方法,通过对IMU时间序列的前向与后向建模,实现中断区段数据修复。实验随机选取两个路段的IMU测量数据,设计数据中断场景,并与传统自回归综合滑动平均模型(autoregressive integrated moving average model,ARIMA)和支持向量机模型(support vector machine,SVM)方法进行对比。结果表明,相比传统方法,模型在IMU数据修复中平均绝对误差(mean absolute error,MAE)降低约30%–47%、决定系数R2提升至0.84,预测精度更优;组合导航解算证实,该方法可加快中断后误差收敛速度,一定程度上抑制误差累积,提高IMU短时中断场景下组合导航定位定姿精度。需要指出的是,该方法依赖完整时间序列信息,因此仅面向事后数据处理应用,不适用于在线导航服务。

     

    Abstract: Objectives: Inertial measurement unit (IMU) data interruption can significantly degrade the positioning and attitude accuracy of integrated navigation systems. Methods: Considering that IMU observations are high-frequency time-series signals with strong temporal correlations between adjacent epochs, a bidirectional long short-term memory (BiLSTM)-based time-series prediction method is proposed for IMU data recovery. The proposed method exploits both forward and backward temporal dependencies to reconstruct missing IMU observations within interrupted segments. Two representative road sections are randomly selected to simulate IMU interruption scenarios, and the proposed method is compared with the autoregressive integrated moving average (ARIMA) model and the support vector machine (SVM) model. Results: Experimental results show that, compared with traditional methods, the proposed approach reduces the mean absolute error (MAE) by approximately 30%–47% and improves the coefficient of determination (R2) to 0.84, demonstrating higher prediction accuracy in IMU data recovery. Integrated navigation results further verify that the proposed method accelerates error convergence after interruption, suppresses error accumulation to a certain extent, and improves positioning and attitude accuracy under short-term IMU outage conditions. Conclusions: The proposed BiLSTM-based method effectively repairs interrupted IMU data and enhances the accuracy of post-processed integrated navigation solutions. However, because it relies on complete time-series information, the method is only applicable to post-processing applications and is not suitable for real-time online navigation services.

     

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