【作者】 刘刚；

【导师】 马广富；

【作者基本信息】 哈尔滨工业大学 ， 控制科学与工程， 2010， 硕士

【摘要】 随着卫星任务的要求不断提高,诸如高精度地球观测和空间监测、卫星监视、分布式平台、星座、卫星交会和星际探测等,对卫星机动能力的要求提出了更高的要求。为了完成姿态快速机动控制任务,传统的执行机构如飞轮等已经不能满足要求,而控制力矩陀螺(CMG)由于其较快的角动量交换速率,可以有效支持快速机动任务的完成。近年来随着CMG的不断小型化,使其应用于卫星成为可能。本文就是在这种背景下,从理论和应用两个方面对应单框架控制力矩陀螺(SGCMG)作为执行机构的卫星大角度姿态快速机动决策以及控制进行了深入的研究,提出了同时解决若干问题的方案。主要完成了以下几个方面的工作:SGCMG虽然具有诸如控制力矩大、响应速度快及功耗低等优点,但其本身具有的奇异性导致了对它的框架操纵律的研究和设计比较困难。本文首先利用欧拉定理建立了含有SGCMG的卫星数学模型,在此基础上分析了金字塔构型SGCMG系统的奇异点分布及特点,针对奇异回避和脱离问题设计了几种基于框架角转速的操纵律,使SGCMG系统在避免或可以脱离奇异的情况下尽可能的跟踪给定力矩。虽然操纵律可以帮助SGCMG系统避免或脱离奇异状态,但在接近或到达奇异状态时还是会带来一定的干扰力矩。为了减少SGCMG系统在机动过程中陷入奇异的次数,同时实现初末角速度均不为零的情况下的快速机动,本文利用伪光谱算法设计了卫星大角度姿态机动的路径规划方法,即导引律。通过跟踪规划出的路径可以使卫星在快速完成机动任务的同时进一步提高SGCMG系统对奇异状态的回避能力。为了精确跟踪规划出的路径,针对存在惯量矩阵参数不确定性和干扰力矩的卫星姿态跟踪控制问题,在已建立的卫星姿态非线性模型基础上又建立了基于误差四元数和误差角速度的卫星运动模型,然后设计了滑模自适应控制算法。该控制算法能够很好地抑制卫星转动惯量存在的参数不确定性以及外界干扰,保证闭环系统的全局渐近稳定性,实现对规划路径的精确跟踪。更多还原

【Abstract】 New satellite missions, such as high-precision earth observation, space surveillance, satellite surveillance, distributed platform, constellation, satellite rendezvous and interplanetary exploration, etc., require large-angle and rapid manuverability. Momentum exchange devices such as reaction wheels can not meet these requirements, since their torque output is rather small compared to control moment gyroscopes(CMG). CMG, with its excellent performance in exchanging mementum, has the ability to fulfill such missions. The miniaturization of CMG makes it possible to mount several CMGs on one small satellite. Some deep research has been done both in theory and application about the decision-making and control for large-angle satellite attitude maneuver using single gimbal control moment gyroscopes(SGCMG). The main contents of this dissertation are summarized as follows:To solve the inherent singularity problem in a system consisiting of several SGCMGs is the most difficult work in the steering logic design. The singularity problem will affect energy consumption and rapid actuation of SGCMG if it is not handled properly. Therefore the model of a satellite using SGCMG is made at first, based on which the distribution and characteristics of singularity in the system of pyramid-type SGCMGs is analyzed. Several singularity avoidance and escape steering strategies based upon gimbal angular velocity are designed and testified to make sure that SGCMGs will produce the comand torque output even in singular gimbal angle configrations.Although the steering logic designed provides an effective means of avoiding and escaping singular states, disturbing torques are innevitably brought in when SGCMGs are close to or reaching the singular states. Therefore, this thesis designs a path planning method based on pseudospectral method, that is, the guidance law to significantly reduce the possibility of reaching the singular states as well as execute the maneuver task even though the initial and final velocities of the satellite are nonzero.Thanks to the guidance law, the maneuver problem is converted to an attitude tracking problem. For attitude tracking control problem of satellite with disturbances and uncertain inertia matrix, a nonlinear satellite model based on error quaternions and velocity errors is builded, according to which we derive the adaptive sliding mode tracking controller to track the desired satellite variables, such as the quaternions, produced by the guidance law. The adaptive control logic can eliminate the influence of parameter uncertainties while the sliding mode control logic is robust to external disturbances. Consequently, the cooperation of these two logic ensues good performance of attitude tracking.更多还原