航天器变转速飞轮微振动主被动一体隔振方法研究

High attitude stability is critical to execute high resolution missions for spacecraft. Flywheels used in spacecraft, however, generate high frequency micro-vibrations that seriously undermine the attitude stability and pointing precision. Therefore, it is highly desirable to suppress micro-vibrations produced by flywheels. However, flywheels are rotating considerably fast on spacecraft, making them different from other general vibration sources, i.e. the strong coupling between flywheels and the isolator must be considered. In the meanwhile, disturbance excitations and the dynamic characteristics of the coupling system are at variance with the rotating speed. As a consequence, neither passive or active strategy alone is adequate to the requirements of flywheel isolation. Thus, to tackle these problems, we propose to conduct fundamental researches to investigate an integrated passive-active isolation of micro-vibrations generated by speed-varying flywheel on spacecraft. The following topics will be studied: 1) Integrated passive-active isolator design and theoretical modeling for speed-varying flywheel; 2) Integrated passive-active isolation methods and optimization for speed-varying flywheel; 3) Grounded experiments for isolation verification. All these studies will help us to understand coupled dynamics of integrated flywheel-isolator system and provide intelligent isolation methods for speed-varying flywheels. These results will establish theoretical fundaments for on-orbit isolation of spacecraft.

航天器的高姿态稳定度是确保高精度航天任务实现的关键之一。飞轮作为航天器姿态控制系统的重要执行机构，在工作时产生的微振动将严重影响航天器的姿态稳定精度，降低相机等星载敏感载荷的工作性能（如成像质量）。因此，必须对飞轮的微振动进行隔离。但是，由于飞轮的高速转动，飞轮与普通振源存在很大不同：飞轮与隔振装置高度耦合，且耦合系统的微振动激励和动力学特性均随转子转速变化。这些特性使得单一的被动或主动隔振方法难以满足隔振要求。本项目以航天器变转速飞轮为对象，开展主被动一体隔振的基础研究。内容包括：变转速飞轮隔振装置设计与耦合动力学建模、主被动一体化隔振方法和优化设计，以及隔振地面试验研究。本项目旨在揭示飞轮与隔振装置的耦合动力学现象，提出变转速飞轮的主被动一体隔振方法，为航天器飞轮隔振的在轨应用奠定理论和技术基础。

飞轮系统是航天器进行姿态控制的重要执行机构。对于高精度航天器，飞轮在提供工作力矩的同时会不可避免的微振动干扰，将大幅降低星载敏感载荷的工作性能，例如降低光学相机的成像质量等。因此，必须对飞轮的微振动进行抑制。本课题针对航天器飞轮系统的微振动抑制问题，以动量轮、控制力矩陀螺等典型飞轮系统为对象，开展变转速飞轮的主被动一体隔振方法研究，包括主被动一体隔振装置设计、耦合建模与分析，主被动一体隔振的控制算法研究，以及隔振后飞轮系统与航天器姿态的耦合动力学与控制的建模与分析等理论研究工作，分别建立了动量轮主被动一体隔振耦合动力学与控制模型、控制力矩陀螺主被动一体隔振耦合动力学与控制模型、隔振后控制力矩陀螺群组与航天器姿态的刚柔耦合动力学与控制模型。同时，根据本课题依托单位国防科技大学“新技术试验卫星H星”装备型号项目对在轨微振动抑制的实际需求，将本课题的相关研究成果进行了工程化应用，开展了H星动量轮在轨微振动监测及抑制的整星系统级设计，大幅降低了H星动量轮对其高分相机载荷成像的干扰，有效地获取了地面目标的清晰视频图像。