This paper proposes a rigid-flexible-Thermal coupling dynamics model for a spacecraft with a composite-laminated solar array in a space thermal environment, and the thermally induced vibration on the spacecraft is studied. The spacecraft system consists of a rigid main body and a flexible composite-laminated solar array formulated with the absolute nodal coordinate formulation. The transient heat conduction equations that involve various heat fluxes are derived as the finite-element formula and the coupled thermo-structural model of the solar array is developed. First, several simulations are conducted to validate the proposed composite-laminated shell element considering the thermal effect. Then, the thermally induced vibration of the low Earth orbit (LEO) spacecraft is discussed when it travels through the umbra, penumbra, and sunlight regions. Moreover, three types of spacecraft dynamics models are compared to show the coupling effect. To further investigate the thermal effects of the attitude-maneuvering spacecraft, the dynamics characteristics of the two spacecraft at different orbit altitudes are simulated and analyzed. The numerical results reveal that the proposed rigid-flexible-Thermal coupling model can correctly describe the thermal effect of LEO spacecraft in the complicated space thermal environment. The thermally induced vibration caused by the spatial heat flux has nonignorable effects on the spacecraft attitude motion. © 2025 American Society of Civil Engineers.

为了解决遥感星群对密集目标观测的效率低下、任务冲突、资源浪费等问题,首先提出了一种区域聚类方法,将互相接近的点目标整合为区域;然后按照卫星轨迹分割为条带,使得卫星单次成像可覆盖多个目标;随后对剩余的目标采用一种单景聚类方法,通过修改载荷指向位置使得卫星瞬时视场能够包含更多目标.使用聚类后的条带和指向点替换原始目标集合进行规划,对指向点采用凝视成像,对条带采用推扫成像.多组仿真算例表明,聚类规划能够有效降低任务数量,缓解目标观测冲突,减少计算耗时,且目标密集程度越高,上述效果愈加明显.

This paper proposes an active shape control method for an antenna control system under a limited number of power supplies with a reduction in weight and cost. An analytical model of a grid reflector with embedded piezoelectric actuators was first established, from which an influence coefficient matrix was derived for controller design. A shape controller was designed by synergistically optimizing the actuator group and power supply voltage. The optimization objectives include the root-mean-square (RMS) error, control energy consumption, and a multiobjective combination of both. The design variables include the actuator group and power supply voltage. A dynamic actuator group design with a detached power supply is proposed to improve the control performance, which also significantly increases the design domain of this optimization problem. A hybrid optimization method is proposed based on the general genetic algorithm and least-squares method to reduce the difficulty and complexity of this optimization problem with a large-dimensional design domain. Numerical simulations were carried out to illustrate the effect of the proposed hybrid optimization control method. The results indicate that the RMS error can be reduced by more than 90%, even if only two power supplies are used. The introduction of a group design with a detached power supply can clearly improve the control performance, especially by reducing the energy consumption. By employing multiobjective optimization with a uniform consideration of the RMS error and control energy consumption, a series of Pareto-optimal results can be obtained, and these results can provide meaningful references for engineering designers. © 2023 American Society of Civil Engineers.

Hypersonic vehicles are difficult to control due to their rapid time variation, dynamic nonlinearity, strong coupling, and model uncertainty. This paper proposes a new nonlinear predictive controller to solve the problem. An improved model predictive controller is used to improve the dynamic control performance of hypersonic vehicles by converting nonlinear dynamics into a state-dependent linear model. The sliding surface can significantly increase the speed of convergence. The radial basis function is used to reduce the influence of system uncertainty. The stability of the proposed controller is analyzed based on the Lyapunov approach. The comparison of simulation results verifies the excellent control performance of the proposed method both in convergence speed and antidisturbance ability.

The strips from region splitting method are critical premise of meta-task generation and task planning for sat-ellite swarm. To achieve the regional observation with high coverage and low overlap ratio and satellites usage, a novel region splitting algorithm is designed based on Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) algorithm. In the hybrid algorithm of GA and PSO, these two algorithms are executed paralleled, and then exchange the best genes and individuals periodically, to overcome the disadvantage of GA's poor local searching ability and PSO's low convergence speed. The encoding method and parallel iterative optimal method are given in detail. Finally, a simulation scenario is designed and executed to verify proposed algorithm, and the effects of algorithm parameters are analyzed by simulation results.

The prescribed performance robust control method for the leader/follower (L/F) formation is proposed in this paper to solve the problem of spacecraft formation flying (SFF) full-process control (FPC). The objective of FPC is to establish an ultra-close formation with the constraint of collision avoidance between two spacecraft, and then to maintain the formation configuration with high-precision accuracy in a period of time. The main contribution of this paper lies in the following three aspects. Firstly, the six-degree-of-freedom (DOF) error dynamics model of SFF is developed to describe the synchronization motion of the L/F system. Secondly, the prescribed performance bound that comprehensively considers transience and transient performance is designed, which is key for the realization of collision avoidance and high-precision accuracy requirements. Finally, combing prescribed performance control and robust control theories, based on the backstepping method, the predefined performance robust controller is designed, and the tracking errors are proven to converge to the predefined performance bounds in the presence of external disturbances by using the predefined performance robust controller. Illustrative simulations are performed to verify the proposed theoretical results.

高轨高分辨率对地观测是各国航天机构探索的一种高效对地观测方式。低轨对地观测航天器受轨道限制,无法保持对一个区域的连续和长期观测。虽然静止轨道具备对特定区域观测的时间分辨率,但由于轨道过高,其分辨率难以保证。因此采用衍射成像技术,将衍射薄膜航天器和成像航天器分别部署于静止轨道,构成共位航天器,以满足观测的时间和空间分辨率要求。本文对共位衍射电磁航天器的动力学建模和控制过程进行深入研究,重点解决共位衍射电磁航天器姿轨一体化动力学建模和控制问题,具体工作包括:针对共位衍射航天器位姿一体化建模问题,基于对偶四元数建立了衍射薄膜航天器的刚柔耦合相对动力学模型和共位两航天器的相对动力学模型。考虑到共位衍射成像系统结构特性,把衍射薄膜航天器抽象成刚柔耦合结构,采用对偶四元数来推导出刚柔耦合动力学方程。考虑到电磁力作为共位衍射成像系统操纵力的众多优势以及对偶四元数在描述相对位姿运动方面的优势,推导出对偶四元数描述的电磁力形式,以此为基础建立基于对偶四元数的两共位航天器相对动力学模型。针对共位航天器对于状态测量和控制精度要求更高的问题,基于非线性相对轨道动力学模型,对衍射成像过程中共位航天器,采用需要相对位置及相对速度信息的非线性鲁棒控制系统,并证明该闭环控制系统能够实现全局渐近收敛。针对衍射成像过程存在空间外界干扰和模型不确定性的状况,运用滑模控制对外部干扰的抗干扰性能、参数变化不敏感的特性和较强的鲁棒性,设计了一种基于自由磁偶极子和切换控制策略的非奇异滑模控制算法,并研究了控制算法的计算效率问题和奇异问题。针对共位衍射航天器姿轨一体化控制问题,在基于对偶四元数的刚柔耦合相对动力学模型基础上,将滑模变结构控制和自适应控制的进行组合,设计了共位衍射航天器的具有自适应辨识的滑模自适应控制方法,并利用李雅普诺夫理论证明了闭环控制系统的稳定性。针对航天器实际运行空间环境复杂、模型参数以及外部干扰不能精确得到等情况,为更好地提升系统鲁棒性,设计了不含模型信息的鲁棒自适应控制器,并对控制器进行了仿真验证。

针对遥感敏捷卫星机动模式对地成像观测，分析挠性附件振动对卫星成像区域和质量的影响。首先利用有限元法和拉格朗日法建立带挠性附卫星的动力学模型；然后通过星地几何法计算成像条带；最后分别选取太阳同步轨道和地球同步轨道，以两个对称的太阳能帆板作为挠性附件，给出数值仿真结果。仿真结果表明，卫星机动完成后，成像区域横滚方向与俯仰方向均偏差较大，导致成像区域错位；太阳帆板振动对成像区域的影响随着其振动减弱而减弱，并逐渐趋于稳定。卫星轨道高度越高，扰动对于卫星成像区域的影响越大，需要更长时间稳定自身姿态。

针对在轨卫星数量不断扩大，空间任务也日趋复杂化，仅依靠地基固定站测控难以满足实际需求的问题，本文研究了基于移动站的协同测控任务规划问题。基于卫星在轨运动的规范化描述，建立了多星多平台测控资源的调度模型，并将复杂空间任务规划问题转化为时间窗口编排问题。基于这一模型提出了一种遗传算法求解策略，该算法设计了一种新型的编码技术，并通过全局型搜索寻求高效、快速、可靠的近似最优解。利用仿真算例验证了该算法的有效性和快速性。

In the real-world situation，the lunar missions’scale and terrain are different according to various operational regions or worksheets，which requests a more flexible and efficient algorithm to generate task paths. A multi-scale ant colony planning method for the lunar robot is designed to meet the requirements of large scale and complex terrain in lunar space. In the algorithm，the actual lunar surface image is meshed into a gird map，the path planning algorithm is modeled on it，and then the actual path is projected to the original lunar surface and mission. The classical ant colony planning algorithm is rewritten utilizing a multi-scale method to address the diverse task problem. Moreover，the path smoothness is also considered to reduce the magnitude of the steering angle. Finally，several typical conditions to verify the efficiency and feasibility of the proposed algorithm are presented. © 2022 Nanjing University of Aeronautics an Astronautics. All rights reserved.