航天器转动惯量参数在轨辨识的最优激励

摘要

根据矩阵分析理论研究了转动惯量参数的可辨识性问题，从姿态动力学方程导出关于未知参数的线性回归模型，将回归矩阵的条件数作为参数可辨识度的定量指标，以可辨识度最大为目标函数建立最优控制模型；应用解最优控制问题的伪谱法，计算控制力矩陀螺的指令轨线，使得惯量参数的辨识精度和收敛速度显著提高；在仿真中采用双无迹卡尔曼滤波算法进行参数辨识，结果验证了所提出的最优激励设计方法可以改善参数辨识性能，同时该方法对先验信息误差具有鲁棒性。%On the basis of matrix analytical theory,the identifiability of inertial moment parameters was studied.A linear regression model in term of the unknown parameters was derived from attitude dynamics equations;the condition number of regression matrix was defined as the quantitative index of identifiability degree;taking the maximum of identifiability degree as objective function,an optimal control model was built. The pseudospectral optimal control was employed to solve the command trajectory of control moment gyro and to improve the identification precision and convergence velocity.The method of dual-unscented Kalman filter identified parameters under simulated circumstances.Results demonstrate that the optimal excitation design can improve the performance of parameter's identification and has high robustness to inaccurate priori information.