无人驾驶飞机在当天变得越来越流行,对它们的申请越过科学和工业的界限,从航空摄影到包装交付再到灾难管理,从该技术中受益。但是在它们变得司空见惯之前,要解决的挑战要使它们可靠和安全。以下论文讨论了与无人驾驶飞机的精确着陆相关的挑战,包括传感和控制的方法及其在各种应用中的优点和缺点。
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随着无人机技术的改进,从监视到航空摄影再到包装交付的这些多功能自动驾驶汽车,已经发现了越来越多的用途,并且这些应用都带来了独特的挑战。本文实施了一个这样一个挑战的解决方案:降落在移动目标上。此问题以前已经通过不同程度的成功解决了,但是大多数实施都集中在室内应用程序上。室外以风和照明等变量的形式提出了更大的挑战,室外无人机更重,更容易受到惯性效应的影响。我们的方法纯粹是基于视觉的,使用单眼摄像机和基准标记来定位无人机和PID控制,以跟随和降落在平台上。
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飞行动物具有高度复杂的物理特征,能够使用翅膀进行敏捷操作。拍打翅膀会产生影响空气动力的复杂唤醒结构,这可能很难建模。尽管可以使用流体结构相互作用对这些力进行建模,但它在计算上非常昂贵且难以制定。在本文中,我们遵循一种更简单的方法,通过使用相对较少的状态得出空气动力,并以简单的状态空间形式呈现它们。该公式利用PrandTL的提升线理论和Wagner的功能来确定作用在机翼上的不稳定空气动力学,然后将其与蝙蝠风格的机器人的实验数据进行比较,称为Aerobat。可以从该模型中评估模拟的尾边涡流脱落,然后可以分析基于尾流的步态设计方法,以改善机器人的空气动力学性能。
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鸟类等动物通过将腿部和空中迁移率与显性惯性作用相结合,广泛使用多模式运动。这种多模式运动壮举的机器人仿生型可以在协商其任务空间的能力方面产生超虚拟系统。本文的主要目的是讨论实现多模式运动的挑战,并报告我们在开发能够多模式运动(腿部和空中运动)的四足动物机器人方面的进展。我们报告了机器人中使用的机械和电气组件,除了为开发多功能多模式机器人平台实现目标的模拟和实验外。
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Automation in farming processes is a growing field of research in both academia and industries. A considerable amount of work has been put into this field to develop systems robust enough for farming. Terrace farming, in particular, provides a varying set of challenges, including robust stair climbing methods and stable navigation in unstructured terrains. We propose the design of a novel autonomous terrace farming robot, Aarohi, that can effectively climb steep terraces of considerable heights and execute several farming operations. The design optimisation strategy for the overall mechanical structure is elucidated. Further, the embedded and software architecture along with fail-safe strategies are presented for a working prototype. Algorithms for autonomous traversal over the terrace steps using the scissor lift mechanism and performing various farming operations have also been discussed. The adaptability of the design to specific operational requirements and modular farm tools allow Aarohi to be customised for a wide variety of use cases.
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Neural network-based approaches for solving partial differential equations (PDEs) have recently received special attention. However, the large majority of neural PDE solvers only apply to rectilinear domains, and do not systematically address the imposition of Dirichlet/Neumann boundary conditions over irregular domain boundaries. In this paper, we present a framework to neurally solve partial differential equations over domains with irregularly shaped (non-rectilinear) geometric boundaries. Our network takes in the shape of the domain as an input (represented using an unstructured point cloud, or any other parametric representation such as Non-Uniform Rational B-Splines) and is able to generalize to novel (unseen) irregular domains; the key technical ingredient to realizing this model is a novel approach for identifying the interior and exterior of the computational grid in a differentiable manner. We also perform a careful error analysis which reveals theoretical insights into several sources of error incurred in the model-building process. Finally, we showcase a wide variety of applications, along with favorable comparisons with ground truth solutions.
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Spiking Neural Networks (SNNs) are bio-plausible models that hold great potential for realizing energy-efficient implementations of sequential tasks on resource-constrained edge devices. However, commercial edge platforms based on standard GPUs are not optimized to deploy SNNs, resulting in high energy and latency. While analog In-Memory Computing (IMC) platforms can serve as energy-efficient inference engines, they are accursed by the immense energy, latency, and area requirements of high-precision ADCs (HP-ADC), overshadowing the benefits of in-memory computations. We propose a hardware/software co-design methodology to deploy SNNs into an ADC-Less IMC architecture using sense-amplifiers as 1-bit ADCs replacing conventional HP-ADCs and alleviating the above issues. Our proposed framework incurs minimal accuracy degradation by performing hardware-aware training and is able to scale beyond simple image classification tasks to more complex sequential regression tasks. Experiments on complex tasks of optical flow estimation and gesture recognition show that progressively increasing the hardware awareness during SNN training allows the model to adapt and learn the errors due to the non-idealities associated with ADC-Less IMC. Also, the proposed ADC-Less IMC offers significant energy and latency improvements, $2-7\times$ and $8.9-24.6\times$, respectively, depending on the SNN model and the workload, compared to HP-ADC IMC.
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基于事件的摄像机最近由于其不同步捕获时间丰富的信息的能力而显示出高速运动估计的巨大潜力。具有神经启发的事件驱动的处理的尖峰神经网络(SNN)可以有效地处理异步数据,而神经元模型(例如泄漏的综合和火灾(LIF))可以跟踪输入中包含的典型时序信息。 SNN通过在神经元内存中保持动态状态,保留重要信息,同时忘记冗余数据随着时间的推移而实现这一目标。因此,我们认为,与类似大小的模拟神经网络(ANN)相比,SNN将允许在顺序回归任务上更好地性能。但是,由于以后的层消失了,很难训练深SNN。为此,我们提出了一个具有可学习的神经元动力学的自适应完全刺激框架,以减轻尖峰消失的问题。我们在时间(BPTT)中利用基于替代梯度的反向传播来从头开始训练我们的深SNN。我们验证了在多车立体化事件相机(MVSEC)数据集和DSEC-FLOW数据集中的光流估计任务的方法。我们在这些数据集上的实验显示,与最新的ANN相比,平均终点误差(AEE)平均降低了13%。我们还探索了几个缩小的模型,并观察到我们的SNN模型始终超过大小的ANN,提供10%-16%的AEE。这些结果证明了SNN对较小模型的重要性及其在边缘的适用性。在效率方面,与最先进的ANN实施相比,我们的SNN可节省大量的网络参数(48倍)和计算能(51倍),同时获得了〜10%的EPE。
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我们提出了一种新颖的轨迹遍历性估计和计划在复杂室外环境中机器人导航的算法。我们将RGB摄像头,3D LIDAR和机器人的探针传感器中的多模式感觉输入结合在一起,以训练预测模型,以估算基于部分可靠的多模式传感器观测值的候选轨迹轨迹的成功概率。我们使用编码器网络对低维特征向量编码高维多模式的感觉输入,并将它们表示为连接的图形,以训练基于注意力的图形神经网络(GNN)模型,以预测轨迹成功概率。我们进一步分别分析图像和点云数据,以量化传感器的可靠性,以增强我们GNN中使用的特征图表示的权重。在运行时,我们的模型利用多传感器输入来预测本地规划师生成的轨迹的成功概率,以避免潜在的碰撞和故障。当一个或多个传感器模态在复杂的室外环境中不可靠或不可用时,我们的算法证明了可靠的预测。我们使用现实世界中户外环境中的点机器人评估算法的导航性能。
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对黑暗时代和系外行星(Farside)进行无线电科学调查的遥远阵列是对Lunar Far Side的拟议任务概念,试图在100正方形的区域内部署和操作128双极化的阵列,偶极天线公里。所得的干涉射电望远镜将提供遥远恒星系统的前所未有的无线电图像,从而可以研究冠状质量弹出和能量颗粒事件的微弱无线电特征,还可以导致在其母星的居住区内检测到磁层周围的磁层。同时,Farside还将在一系列红移(z大约50-100)中以全球21厘米信号的全局信号来测量早期宇宙的“黑暗年龄”。阵列中的每个离散天线节点都通过通信和电源系绳连接到中央集线器(位于降落器)。节点是由Cold =可操作的电子设备驱动的,该电子设备连续监测极宽的频率(200 kHz至40 MHz),该频率超过了基于地球的望远镜的能力,该望远镜的功能由两个数量级。实现这种开创性的能力需要在月球表面上制定强大的部署策略,这对于现有高的TRL技术(演示或正在积极发展)是可行的,并且能够在下一代商业地面上传递到地​​表,例如蓝色Origin的蓝月亮着陆器。本文介绍了一种天线包装,放置和表面部署贸易研究,该研究利用了NASA的Jet Propuls实验室开发的束缚移动机器人的最新进展,该机器人用于部署平坦的,天线隔离的,带有光学通信和电源传输的磁带。功能。
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