机动加速度辅助的航姿系统扩展卡尔曼滤波

低精度航姿系统一般采用基于重力场和地磁场矢量观测的6态扩展卡尔曼滤波,载体长时间机动时,模型存在较大误差,无法保持稳定的姿态精度。将载体机动加速度描述为当前统计模型,提出了一种机动加速度辅助的9态扩展卡尔曼滤波,其状态变量包括三个姿态角误差、三轴陀螺零偏误差和三轴载体加速度误差,观测量为三轴加速度误差和三轴地磁场误差。实验表明,将航姿系统固定在转台上产生0.6 g的向心加速度时,9态扩展卡尔曼滤波在对机动加速度进行稳定估计的同时,姿态精度保持在1度以内。

Maneuvering acceleration assisted extended Kalman filter for attitude and heading reference system

The low cost AHRS(attitude and heading reference system) commonly adopt 6-state EKF(extended Kalman filter) based on the gravity field and the magnetic field vector observations.When the carrier maneuvered with a long time,the model presented big errors and 6-state EKF could not get stable attitude accuracy.The maneuvering acceleration is described with current statistical model.A 9-state EKF is introduced with 9 states of three attitude errors,three-axis gyroscopes bias errors and three-axis maneuvering acceleration errors.The observations includ three-axis acceleration errors and three-axis magnetic filed errors of the earth.When AHRS rotates with acceleration centripetal of 0.6 g on the rotation table,the experimental results show that 9-state EKF could get stable estimation of three-axis maneuvering accelerations and the attitude accuracy is better than 1 degree.