安全约束下的空间翻滚目标涡流消旋稳定控制

针对空间翻滚目标涡流消旋任务执行效率低和抵近安全无保证的问题，首先基于椭球包络法给出了服务星机动轨迹的直接线性凸化安全约束，以确保机动过程的安全性和最优轨迹跟踪问题的有限时间可解性；设计了垂直构型下空间消旋任务的抵近期望轨迹以增强服务星消旋力矩的作用强度，缩短任务周期。在此基础上，提出了一种反馈线性化的收缩模型预测控制(FLC MPC)算法，有效跟踪所提出的期望轨迹，并严格保证安全约束及控制输入约束下受控系统的稳定性。最后，利用所提出的控制方法对阿丽亚娜 4火箭上面级进行消旋仿真，结果表明该方法能有效提高消旋效率，并保证服务星的安全稳定。     

Fast calculation method for mission opportunities in orbital interception and rendezvous problems

This paper proposes a fast calculation method to solve all mission opportunities for orbital interception and orbital rendezvous under the impulse-magnitude constraint. Different from the existing search methods, the proposed method does not need to solve Lambert’s problem in the whole process. Three cases are considered for either departure time or transfer time being free, or both being free. For fixed departure time, the feasible windows of transfer time are obtained by solving a single-variable nonlinear equation only of terminal true anomaly. Similarly, for fixed interception (or rendezvous) time, the feasible windows of departure time are obtained. For free departure time and free transfer time, all mission opportunities are obtained by using a one-dimensional search strategy. The hyperbolic-transfer and the multiple-revolution cases are also analyzed. Numerical results show that the proposed method is superior to the typical pork-chop plot method and the two-dimensional launch window method in computational time.     

短切碳纤维增强环氧树脂形状记忆复合材料的制备与性能研究

为实现形状驱动能耗与复合材料力学性能的最佳配合，本文在热致环氧形状记忆聚合物基体中提高增韧剂新戊二醇二缩水醚（NGDE）含量来降低其玻璃化转变温度，同时添加短切碳纤维（SCF）来抵消由增韧剂引起的刚度降低负面效果。通过实验研究了不同NGDE、SCF含量对复合材料形状记忆转变温度、形状记忆性能和力学性能的影响。结果表明，增加NGDE含量可将环氧聚合物基体的形状记忆转变温度从90 ℃降至43 ℃，其储能模量和弯曲模量也随之降低。在11wt%NGDE上添加SCF后，复合材料的玻璃态储能模量、橡胶态储能模量、弯曲模量最高可提高至原始试样的1.9倍、7倍和2.4倍。     

Three-dimensional time-varying sliding mode guidance law against maneuvering targets with terminal angle constraint

This paper deals with the problem of intercepting maneuvering targets with terminal angle constraints for missiles subjected to three-dimensional non-decoupling engagement geometry.To achieve the finite-time interception and satisfactory overload characteristics, a time varying sliding mode control methodology is developed based on a time base generator function. The main feature of the proposed guidance law guarantees the Line-of-Sight(LOS) angles to converge to small neighborhoods of the desir...     

国产高模碳纤维/环氧复合材料在太阳翼基板上的应用研究

基板是空间太阳电池阵电池电路的安装基础，“上下碳纤维复合材料网格面板+铝蜂窝芯+聚酰亚胺膜”是基板的典型结构。高模量碳纤维作为太阳翼核心关键原材料，必须实现自主可控，避免受制于人。为此，开展了国产高模碳纤维CCM40J-6K/环氧复合材料在太阳翼基板上的应用试验研究，提出了CCM40J-6K/环氧复合材料在产品应用上的宏观力学、微观网格抗拉脱、聚酰亚胺膜粘贴等三个关键环节，针对性地设计并实施了常温和高低温交变力学性能、网格面板节点结合力、聚酰亚胺膜粘贴性能以及基板结构热循环性能等5个方面的测试验证。验证结果表明：CCM40J-6K太阳翼基板各项力学性能与进口M40JB-6K相当，可以沿用原M40JB-6K相关基板成型工艺，单层及多层铺层基板试验件能够经受高低温交变及热循环恶劣环境，试验件试验前后力学性能无明显变化，且聚酰亚胺膜无脱粘现象，网格节点拉伸强度国产碳纤维网格面板相比进口碳纤维网格面板高18.9%。说明国产碳纤维CCM40J-6K能够应用于太阳翼基板结构研制。     

An improved altimeter-derived gravity anomaly from shipborne gravity based on the mean sea surface height constraint factors method

Coastal marine gravity modeling faces challenges due to the degradation of the quality and poor coverage of altimeter data in coastal regions. The effective fusion of shipborne gravity data and altimeter-derived marine gravity data can make shipborne gravity data more useful for the accurate estimation of altimeter-derived coastal marine gravity. A mean sea surface height constraint factor (MSSHCF) method based on the ordinary kriging method and the remove-restore technique is proposed to fuse altimeter-derived gravity model with shipborne gravity data. In this method, all data are standardized during the interpolation process to reduce the error and mean sea surface as a vertical variable is added to the semi-variance function in ordinary kriging to obtain the residual shipborne gravity as corrected data source. The coastal marine gravity models V2.1 and V3.1 which fused altimeter-derived gravity data with shipborne gravity data and V1.1 without shipborne gravity data at a spatial resolution of 1′×1′ can be obtained. Validation experiments show that the accuracy of the gravity model V3.1 obtained by the MSSHCF method more closely agrees with the validated gravity model DTU17 and SS V31 than the model V2.1 obtained by the ordinary kriging interpolation method and the V1.1 model. Our results were validated against shipborne gravity data; the accuracy of model V3.1 was 4.95 % higher than the model V1.1 in South China Sea area A and 2.48 % higher in South China Sea area B. Meanwhile, the accuracy of model V3.1 was 2.07 % higher than model V2.1 in South China Sea area A and 2.42 % higher in South China Sea area B. The effects of distance from the coast and sea depth on the marine gravity model were also evaluated. The results show that the gravity model V3.1 has higher accuracy with the change in ocean distance and depth than the V2.1 and V1.1 gravity models. Thus, our study shows that the MSSHCF method effectively refines coastal altimeter-derived gravity using shipborne gravity data.     

Formation control for networked multiagent systems with a minimum energy constraint

Minimum-energy formation achievement problems for networked multiagent systems are investigated, where information networks with leaderless and leader-follower structures are respectively addressed and information networks are randomly switching. The critical feature of this work is that the energy constraint is minimum in the sense of the linear matrix inequality, but limited-budget control and guaranteed-cost control cannot realize a minimum-energy formation. Firstly, the leaderless minimum-energy formation control problem is converted into an asymptotic stability one via a nonsingular transformation and state space decomposition, and based on linear matrix inequality techniques, sufficient conditions for analysis and design of leaderless minimum-energy formation achievement are proposed, respectively, which can be solved by the generalized eigenvalue method. Then, main results of minimum-energy formation achievement of leaderless networked multiagent systems are extended leader-follower networked multiagent systems, where the asymmetric property of the leader-follower information network is well dealt with by two nonsingular transformations. Finally, two simulation examples are shown to verify the main results for minimum-energy formation achievements of leaderless and leader-follower networked multiagent systems, respectively.