移动质心飞行器的参数辨识和补偿控制

Parameter Identification and Compensation Control for Moving Mass Vehicle

受质量块大小和位移的限制,移动质心不能像空气舵那样产生很大的力矩,因此飞行器的再入攻角对静稳定度很敏感,尤其在小静稳定度下,静稳定度稍有改变,配平攻角将发生很大变化。飞行器再入过程中的烧蚀、侵蚀以及边界层转捩所造成的小不对称量所产生的不对称力矩与质心移动后产生的控制力矩相比,不是小量。以所建立的移动质心控制飞行器的数学模型为基础,辨识飞行器静稳定度和小不对称量,对小不对称量造成的气动力矩用前馈-反馈复合控制加以补偿。仿真分析表明,移动质心控制对高速再入的飞行器具有良好的末修能力,能有效提高再入段的控制精度。

Moving mass control can not produce a large mount of moment like aerodynamic surfaces due to limit of size and displacement, so angle of attack of vehicle is very sensible to static stability. Trim angle of attack will change very largely especially in small degree of static stability. Asymmetry moment, which is produced by ablation, erosion and boundary layer transition during the reentry phase, is not small compared with control moment produced by moving mass. Degree of static stability and small asymmetry is identified based on the built mathematical model of moving mass control for vehicle. Aerodynamic moment resulting from small asymmetry is compensated by feed forward-feedback compound control and incidence dispersion is decreased effectively. Simulation indicates that moving mass control is effective in terminal correction and can improve the precision for supersonic re-entry vehicle.