【作者】 钱山；

【导师】 蔡洪； 张士峰；

【作者基本信息】 国防科学技术大学 ， 航空宇航科学与技术， 2010， 博士

【摘要】 自主在轨服务凭借其成本低、风险小、隐蔽性高、军事利用价值强等特点,成为了目前乃至未来空间技术新的研究与发展方向,同时也对自主交会对接和组合航天器姿态控制等关键技术提出了新的要求。本文以此为背景,研究解决了几个关键问题,主要内容如下:设计了自主交会对接最终逼近段惯性/视觉组合相对测量系统。其基本思路是引入IMU测量追踪航天器的对接控制运动信息,利用相对运动方程解算两航天器的相对运动参数,克服视觉测量输出频率低、视场小等不足,提高测量系统可靠性。针对该系统的设计问题,首先基于C-W交会运动模型论证了引入IMU进行相对测量的可行性,研究了惯性/视觉组合相对导航算法;然后,设计了组合相对测量系统的地面演示验证方案,推导了地面试验相对运动模型及其组合导航算法,分析了地面试验方案的适用性,进行了数值仿真和地面试验。结果表明,该系统达到设计目标,满足自主交会对接相对导航精度要求。研究了在轨服务组合航天器姿态动力学参数在轨辨识问题。针对存在液体质量传输的在轨加注典型服务任务,基于六点基本假设对加注航天器和加注设备进行了合理简化,利用多体航天器惯量张量建模结论,建立了在轨加注全过程组合航天器质量特性参数的时变模型。针对一般的在轨服务任务,研究了组合航天器姿态动力学特性参数的最小二乘估计方案,引入总体最小二乘准则,对一般最小二乘方法进行了改进,借鉴牛顿迭代法的思想设计了非线性参数估计问题的解析算法。进一步研究了一般在轨服务任务姿态动力学特性参数的滤波方案,针对具有强非线性特性的滤波估计模型,引入非线性滤波算法SIEKF进行求解,分析了该算法的基本原理和实现过程。仿真结果表明,对于具有较强非线性特性的参数估计问题,SIEKF算法收敛速度较快,估计精度较高。研究了组合航天器多敏感器联合姿态确定方法。基于六个最小姿态测量系统,提出了组合航天器有陀螺姿态确定系统的联合式Kalman、无陀螺姿态确定系统的联合式UKF和联合式NPF三种融合定姿方案,进一步提高了组合航天器姿态确定系统的可靠性和容错性。针对联合姿态确定方案中各子滤波器没有私有状态变量的特点,对联合滤波器进行了算法改进,有效提高了算法的运算效率,在此基础上进一步研究了联合式Kalman方案和联合式UKF方案的算法实现过程。从算法结构和估计准则两个方面,论证了NPF算法与Kalman滤波算法的等效性,奠定了联合式NPF滤波算法提出的理论基础,研究了联合式NPF方案的算法实现过程。仿真结果验证了上述方案的有效性。研究了组合航天器分散协同姿态控制技术。根据分散协同控制思想,设计了组合航天器姿态控制方案,分别对中心刚体和挠性部件采用主动分散协同控制和被动集中控制,研究了分散协同控制指令分配的依据和卸载次数最少的指令分配准则。针对控制方案的实现问题,设计了反作用飞轮系统的复合非线性控制律和磁力矩器的卸载控制律,采用了基于输入输出线性化控制和自适应模糊滑模控制的复合控制算法,解决了存在动力学参数变化、不确定性干扰等非线性影响因素的组合航天器姿态高精度控制和挠性附件的振动控制问题。通过与集中控制方案的比较分析,说明该方案能够有效降低在轨服务航天器姿态控制系统的配置要求。自主在轨服务技术将是今后航天技术最重要的发展方向之一,本文的研究工作可为我国在轨服务自主交会对接相对测量和组合航天器姿态控制技术的发展提供方案参考和技术支持。更多还原

【Abstract】 With the advantages of low-risk, relatively low-cost, potentially high concealment and important military value, on-orbit autonomous servicing has become the new research focus in the future space technology. The new GNC techniques of autonomous rendezvous and docking and attitude control for combined spacecrafts are claimed. Several key problems are studied, and the main results achieved in this dissertation are summarized as follows.An integrated IMU/Vision relative navigation system for the final approach phase of autonomous rendezvous and docking is designed. The inertial measurement unit to measure the motion information of chaser spacecraft, and the method of using relative motion equations to calculate relative motion parameters, are intreducted, overcoming the angles-only output shortcomings including low output frequency and small field of view and improving the system reliability. Based on the C-W rendezvous motion model, the feasibility of applying IMU into relative navigation system is verified, and the integrated IMU/Vision relative navigation algorithm is studied. On-the-ground experimental relative motion model and integrated measurement algorithm are formulated, and on-the-ground validation experiment for integrated IMU/Vision relative navigation system is designed. Analyzing the applicability of the proposed scheme, numerical simulation and on-the-ground experiment show that the system achieves the design goals and satisfies the control precision requirements for autonomous rendezvous and docking.The on-line identification approaches concerning attitude dynamic parameters of on-orbit servicing combined spacecrafts are studied and proposed. Based on the six basic hypotheses, the refueling spacecrafts and equipments for on-orbit refueling missions are simplified, and the mass property time-variation model for the whole refueling process is formulated by using the inertia tensor model conclusions of multi-body spacecraft. The least squares estimate scheme for attitude dynamic parameters of combined spacecrafts is studied, and the theoretical method for nonlinear parameter estimation problem is designed by introducing total least squares principle improving the general least square method. The filter approaches related to attitude dynamic parameters for general on-orbit missions are furtherly studied, and a new nonlinear filter algorithm– Super Iterated Extended Kalman Filter is introduced to solve the strong nonlinear filtering model. The simulations demonstrate that the SIEKF algorithm has rapid convergence rate and high estimation precision for strong nonlinear parameter estimation problem.The multi-sensors united attitude determination approaches for combined spacecraft are studied and proposed. Based on the six minimum attitude measurement systems, three of the filter algorithms are proposed for attitude determination fusing system, specifically the combined Kalman filter algorithm with gyroscope, combined Uncented Kalman filter and combined Nonlinear Predictive Filter without gyroscope, in order to improve the reliability and fault-tolerance of attitude determination system for combined spacecrafts. Considering each local filters having no private state variables, the combined filter algorithms are improved and the compute efficiency is enhanced. From algorithm structure and algorithm principle, the equivalent of both NPF and Kalman filter is demonstrated to establish the theoretical basis of NPF algorithm. The simulations demonstrate the proposed schemes are efficient.The decentralist cooperative attitude control approaches for combined spacecraft are studied and proposed. Based on the active distributed collaboration control to central rigid body and the passive control scheme to flexible components, the attitude control scheme for combined spacecrafts is designed. Aiming at the realization of the control scheme, the basis of command allocation for decentralist cooperative attitude control is studied, and the command allocation criterions for least unloading times are analyzed. The hybrid nonlinear control law of reaction wheel system and the unload control law of magnetic moment are studied. Based on the hybrid algorithms containing input-output nonlinear control and adaptive fuzzy control, the high precision attitude control problem for combined spacecraft including the variety of system dynamic parameter and uncertainty disturbance, and the vibration control problem for flexible accessories, are solved. Compared with the centralized control scheme, the proposed scheme can reduce the configuration requirements of attitude control system for on-orbit servicing spacecraft.On-orbit servicing technology will be one of the most important developing directions for spacecraft technologies, the research in this dissertation can provide scheme references and technique support.更多还原