大型三轴气浮台转动惯量和干扰力矩高精度联合辨识技术

利用三轴气浮台对遥感卫星进行载荷平台一体化全系统闭环物理仿真,可模拟卫星在轨运行时的动力学特性,验证整星在轨状态下的姿控特性和相机成像特性等。高精度辨识气浮台转动惯量和综合干扰力矩为三轴气浮台质量特性调整及量化评估整星级试验性能提供重要参数。文章提出一种新的大型三轴气浮台转动惯量和干扰力矩联合辨识技术,通过台上飞轮对三轴施加激励作用,利用激光陀螺等姿态测量数据实现对台体惯量矩阵和干扰力矩的高精度联合辨识。与传统辨识方法不同,该技术仅利用本体角速度信息,不需要角加速度信息,避免了角速度微分引起的噪声放大,将转动惯量辨识相对误差控制在3.5%以内,气浮系统综合干扰力矩优于0.003 N·m,满足了高精度参数辨识需求。

High-accuracy joint identification technique for moment of inertia and interference torque of large-scale three-axis air-bearing simulator

The system-wide closed-loop physical simulation on a three-axis air-bearing simulator, integrated with the payloads of a high-accuracy remote sensing satellite, can be used to simulate the dynamics of the in-orbit satellite and verify the behavior of the attitude control system and the imaging system. The high-accuracy identification technique for the moment of inertia and the interference torque is used to determine the parameters for the adjustment of the simulator mass property and the quantitative assessment of the whole satellite test performance. In this paper, a new identification technique of using the reaction wheels to generate the excitation and using the laser gyros to determine the simulator attitude is proposed, which is different from the traditional methods. With this technique, only the angular velocity is used without the need for the angular acceleration, thus, the noise amplification due to the differentiation of the angular velocity can be avoided. The relative error of the proposed identification technique for the moment of inertia is below 3.5%, and the identification results show that the aggregation interference torque of the simulator system is below 0.003 N·m, which can meet the requirement of the high-accuracy parameter identification.