一种单子样旋转矢量姿态算法

旋转矢量姿态算法可有效抑制高动态环境下捷联惯导系统(SINS)产生的圆锥误差。当直接应用多子样旋转矢量姿态算法时,会降低系统姿态更新频率;若要保持姿态更新频率,则需要提高采样频率,从而增加了导航计算机的硬件负担,并导致量化误差突出。针对上述不足,提出了一种利用当前及前N个姿态更新周期角增量的单子样旋转矢量姿态算法,并在典型圆锥运动条件下推导了算法补偿项系数。此外,由于陀螺输出经过数字滤波处理后其幅频特性的改变会影响圆锥误差的补偿效果,根据滤波器特性推导了单子样旋转矢量姿态算法的修正算法,以便于在工程中推广应用。该算法在不降低姿态更新频率的同时,可获得较高的解算精度,适于高动态环境应用,实验结果验证了上述算法的正确性和有效性。

A Single-Sample Rotation Vector Attitude Algorithm

When applying multi-sample rotation vector algorithms in engineering directly, the attitude update frequency of Strap-down Inertial Navigation System (SINS) will be decreased. To keep the attitude update frequency, the sample frequency should be increased. It will introduce additional hardware burden and quantization error. To solve this problem, a single-sample rotation vector algorithm was developed utilizing the gyro samples from current and last N updating periods. The proposed algorithm was equivalent to increase gyro samples without decreasing the attitude update frequency. The algorithm coefficients and error expression were deduced under classical coning motion. Besides, to compensate the performance degradation caused by taking the filtered gyro data as input for rotation vector algorithms, the proposed algorithm was tuned according to the frequency response characteristics of the filter. The experiment results verify the conclusions.