共查询到18条相似文献,搜索用时 62 毫秒
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传统的无人飞行器(UAV)视觉编队控制律考虑约束的能力不足,制约了其工程实际应用。针对不足,基于预测控制方法设计了一种能够显式考虑约束的视觉编队控制律,该控制律通过滚动求解有限时域优化问题得到跟随飞行器(follower)的控制输入。利用相对距离变化率和视线方位角变化率预测值与实测值的偏差信息,提出了领航飞行器(leader)加速度的在线估计算法。仿真结果表明,所设计的编队控制律能够控制follower飞行器快速跟随leader飞行器形成期望的编队,所提出的leader飞行器加速度估计方法可行,具有较小的估计误差。 相似文献
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结合飞行器突入雷达探测区域的进入角与雷达有效反射截面积的关系 ,对空军作战突防编队中干扰机与攻击机的位置部署进行了探讨。 相似文献
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结合飞行器突入雷达探测区域的进入角与雷达有效反射截面积的关系,对空军作战突防编队中干扰机与攻击机的位置部署进行了探讨。 相似文献
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为了实现在复合干扰下六旋翼无人机编队的稳定飞行,提出了一种快速终端滑模鲁棒控制方法。首先,描述了领导-跟随编队拓扑结构并建立了六旋翼无人机的6自由度运动模型,然后,设计了编队外环控制律将编队指令转换为姿态指令,并通过设计编队内环控制律解算得到旋翼转速指令,最后,引入自适应律来估计复合干扰,实现了六旋翼无人机编队的稳定飞行。仿真实验结果表明:所提方法与滑模控制方法相比能够更加快速地实现六旋翼无人机的编队稳定飞行,最大轨迹误差仅为0.2 m,复合干扰最大估计误差仅为0.1 m/s2,表现出了更优的控制效果。 相似文献
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为了克服未知的执行器故障对四旋翼无人机编队飞行的影响,提出了一种基于动态规划的最优协同容错控制律。首先,建立了四旋翼无人机模型,然后,基于动态规划设计了最优协同控制律,利用RBF神经网络逼近最优性能指标函数,设计了自适应律来估计未知的执行器故障,最终得到的最优协同容错控制律可实现对无人机编队飞行的高精度控制。通过对比仿真验证了设计的控制律具有更优的编队控制效果,编队飞行的最大轨迹跟踪误差仅为0.04 m,控制精度较高,设计的自适应律具有更优的故障估计效果,最大估计误差仅为0.05 N·m,实现了对四旋翼无人机编队的安全稳定控制。 相似文献
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提出了一种基于改进指数趋近律的滑模控制器的无人机编队建模与控制方法。首先采用弹性系统模型对无人机编队进行动力学分析,把每个无人机看作一个质量点,无人机之间的位置关系可以视为编队控制时的约束力;在此基础上采用一种固定的通信拓扑,对编队平衡状态进行分析,建立无人机编队的动力学模型。同时利用一种基于改进指数趋近律的滑模控制器实现无人机编队协同控制,以此加快系统稳定的收敛速度,削弱传统滑模控制器的抖振现象,保证无人机编队协同控制的稳定性。最后,通过实际无人机编队飞行试验来验证无人机编队动力学模型的可行性与无人机编队控制器的稳定性。 相似文献
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Depletion and hillock formation were examined in-situ in a scanning electron microscope (SEM) during electromigration of bamboo
Al interconnect segments. Hillocks formed directly at the anode ends of the segments by epitaxial addition of Al at the bottom
Al/TiN interface. Depletion occurred nonuniformly from the cathode end and stopped once the distance between the leading void
and the hillock reached the critical length for electromigration at the given current density. A modified equation for the
drift velocity is proposed, which includes the effect of nonuniform depletion and predicts that interconnects with nonuniform
depletion are more reliable than those with uniform depletion. 相似文献
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战斗机人工势场在主从编队引导控制中的应用 总被引:1,自引:1,他引:0
引入战斗机人工势场的概念,建立针对主从编队引导控制的模型。在分析势、势场力的基础上,构建战斗机编队的队形势以及队形力函数。建立编队控制模型,编队队形的结构与队形参考点有关,参考点的数量和位置由队形和队形控制方式决定,主从编队控制以长机为队形参考点。建立了基于队形力的主从编队控制模型,并应用于实际领航者之中。仿真表明飞行误差收敛速度快,僚机能够稳定跟踪领航者的飞行轨迹,并保持较小的跟踪误差(20~40m)。在密集编队控制中,仍需改进控制器和优化参数;在稀疏队形和分散队形中,完全可以满足控制需要。 相似文献
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考虑舰船安全的原则,从保障编队电子对抗的角度定性讨论了在实施电子对抗作战时舰艇编队的组成原则及编队队形,并定量分析确定了编队在实施不同的电子对抗方法和手段时,舰艇之间的安全间距,得出符合实际作战需求的结论。结论对复杂战场条件下舰艇编队实施电子对抗具有一定的指导意义。 相似文献
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We have observed phase nucleation in ultrathin Ti films deposited. upon Si substrates using transmission electron diffraction
(TED). After subjecting the samples to vacuum annealing at various temperatures, we find that the first compound phase formed
is a metastable super structure of the Si lattice. We present evidence that this phase is the same one seen previously in
thicker films which was labeled as “TiSi”. 相似文献
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Lian Zhong Zhe Sun Seunglok Lee Seonghun Jeong Sungwoo Jung Yongjoon Cho Jeewon Park Jaeyeong Park Seong-Jun Yoon Changduk Yang 《Advanced functional materials》2023,33(49):2305450
Volatile solid additives are an effective strategy for optimizing morphology and improving the power conversion efficiencies (PCEs) of organic solar cells (OSCs). Much research has been conducted to understand the role of solid additives in active layer morphology. However, it is crucial to delve deeper and understand how solid additives affect the entire morphology evolution process, from the solution state to the film state and the thermal annealing stage, which remains unclear. Herein, the use of a highly crystalline solid additive, phenoxathiin (Ph), in D18-Cl:N3-based OSCs and study its impact on morphology formation and photovoltaic performance is presented. Owing to its good miscibility with the acceptor N3, Ph additive can not only extend the time for the active layer to form from the solution state to the film state, but also provide sufficient time for acceptor aggregation. After thermal annealing, Ph solid additive volatilizes better aligned the N3 molecules and formed a favorable hybrid morphology. Consequently, the D18-Cl:N3–based OSC exhibited an outstanding PCE of 18.47%, with an enhanced short-circuit current of 27.50 mA cm−2 and a fill factor of 77.82%. This research is spurring the development of high-performance OSCs using solid additives that allow fine control during morphology development. 相似文献