The increasing interest in autonomous robots with a high number of degrees of freedom for industrial applications and service robotics demands control algorithms to handle multiple tasks as well as hard constraints efficiently. This paper presents a general framework in which both kinematic (velocity- or acceleration-based) and dynamic (torque-based) control of redundant robots are handled in a unified fashion. The framework allows for the specification of redundancy resolution problems featuring a hierarchy of arbitrary (equality and inequality) constraints, arbitrary weighting of the control effort in the cost function and an additional input used to optimize possibly remaining redundancy. To solve such problems, a generalization of the Saturation in the Null Space (SNS) algorithm is introduced, which extends the original method according to the features required by our general control framework. Variants of the developed algorithm are presented, which ensure both efficient computation and optimality of the solution. Experiments on a KUKA LBRiiwa robotic arm, as well as simulations with a highly redundant mobile manipulator are reported.

With more and more data being collected, data-driven modeling methods have been gaining in popularity in recent years. While physically sound, classical gray-box models are often cumbersome to identify and scale, and their accuracy might be hindered by their limited expressiveness. On the other hand, classical black-box methods, typically relying on Neural Networks (NNs) nowadays, often achieve impressive performance, even at scale, by deriving statistical patterns from data. However, they remain completely oblivious to the underlying physical laws, which may lead to potentially catastrophic failures if decisions for real-world physical systems are based on them. Physically Consistent Neural Networks (PCNNs) were recently developed to address these aforementioned issues, ensuring physical consistency while still leveraging NNs to attain state-of-the-art accuracy. In this work, we scale PCNNs to model building temperature dynamics and propose a thorough comparison with classical gray-box and black-box methods. More precisely, we design three distinct PCNN extensions, thereby exemplifying the modularity and flexibility of the architecture, and formally prove their physical consistency. In the presented case study, PCNNs are shown to achieve state-of-the-art accuracy, even outperforming classical NN-based models despite their constrained structure. Our investigations furthermore provide a clear illustration of NNs achieving seemingly good performance while remaining completely physics-agnostic, which can be misleading in practice. While this performance comes at the cost of computational complexity, PCNNs on the other hand show accuracy improvements of 17-35% compared to all other physically consistent methods, paving the way for scalable physically consistent models with state-of-the-art performance.

Synthetic data generation has recently gained widespread attention as a more reliable alternative to traditional data anonymization. The involved methods are originally developed for image synthesis. Hence, their application to the typically tabular and relational datasets from healthcare, finance and other industries is non-trivial. While substantial research has been devoted to the generation of realistic tabular datasets, the study of synthetic relational databases is still in its infancy. In this paper, we combine the variational autoencoder framework with graph neural networks to generate realistic synthetic relational databases. We then apply the obtained method to two publicly available databases in computational experiments. The results indicate that real databases' structures are accurately preserved in the resulting synthetic datasets, even for large datasets with advanced data types.

Reinforcement Learning (RL) generally suffers from poor sample complexity, mostly due to the need to exhaustively explore the state space to find good policies. On the other hand, we postulate that expert knowledge of the system to control often allows us to design simple rules we expect good policies to follow at all times. In this work, we hence propose a simple yet effective modification of continuous actor-critic RL frameworks to incorporate such prior knowledge in the learned policies and constrain them to regions of the state space that are deemed interesting, thereby significantly accelerating their convergence. Concretely, we saturate the actions chosen by the agent if they do not comply with our intuition and, critically, modify the gradient update step of the policy to ensure the learning process does not suffer from the saturation step. On a room temperature control simulation case study, these modifications allow agents to converge to well-performing policies up to one order of magnitude faster than classical RL agents while retaining good final performance.

Despite the immense success of neural networks in modeling system dynamics from data, they often remain physics-agnostic black boxes. In the particular case of physical systems, they might consequently make physically inconsistent predictions, which makes them unreliable in practice. In this paper, we leverage the framework of Irreversible port-Hamiltonian Systems (IPHS), which can describe most multi-physics systems, and rely on Neural Ordinary Differential Equations (NODEs) to learn their parameters from data. Since IPHS models are consistent with the first and second principles of thermodynamics by design, so are the proposed Physically Consistent NODEs (PC-NODEs). Furthermore, the NODE training procedure allows us to seamlessly incorporate prior knowledge of the system properties in the learned dynamics. We demonstrate the effectiveness of the proposed method by learning the thermodynamics of a building from the real-world measurements and the dynamics of a simulated gas-piston system. Thanks to the modularity and flexibility of the IPHS framework, PC-NODEs can be extended to learn physically consistent models of multi-physics distributed systems.

许多涉及某种形式的3D视觉感知的机器人任务极大地受益于对工作环境的完整知识。但是，机器人通常必须应对非结构化的环境，并且由于工作空间有限，混乱或对象自我划分，它们的车载视觉传感器只能提供不完整的信息。近年来，深度学习架构的形状完成架构已开始将牵引力作为从部分视觉数据中推断出完整的3D对象表示的有效手段。然而，大多数现有的最新方法都以体素电网形式提供了固定的输出分辨率，这与神经网络输出阶段的大小严格相关。尽管这足以完成某些任务，例如导航，抓握和操纵的障碍需要更精细的分辨率，并且简单地扩大神经网络输出在计算上是昂贵的。在本文中，我们通过基于隐式3D表示的对象形状完成方法来解决此限制，该方法为每个重建点提供了置信值。作为第二个贡献，我们提出了一种基于梯度的方法，用于在推理时在任意分辨率下有效地采样这种隐式函数。我们通过将重建的形状与地面真理进行比较，并通过在机器人握把管道中部署形状完成算法来实验验证我们的方法。在这两种情况下，我们将结果与最先进的形状完成方法进行了比较。

动作识别是人形机器人与人类互动和合作的基本能力。该应用程序需要设计动作识别系统，以便可以轻松添加新操作，同时识别和忽略未知的动作。近年来，深度学习的方法代表了行动识别问题的主要解决方案。但是，大多数模型通常需要大量的手动标记样品数据集。在这项工作中，我们针对单发的深度学习模型，因为它们只能处理课堂的一个实例。不幸的是，一击模型假设在推理时，识别的动作落入了支持集中，当动作位于支持集外时，它们会失败。几乎没有射击开放式识别（FSOSR）解决方案试图解决该缺陷，但是当前的解决方案仅考虑静态图像而不是图像序列。静态图像仍然不足以区分诸如坐下和站立之类的动作。在本文中，我们提出了一个新颖的模型，该模型通过一个单发模型来解决FSOSR问题，该模型用拒绝未知动作的歧视器增强。该模型对于人体机器人技术中的应用很有用，因为它允许轻松添加新类并确定输入序列是否是系统已知的序列。我们展示了如何以端到端的方式训练整个模型，并进行定量和定性分析。最后，我们提供现实世界中的例子。

飞机行业不断努力在人类的努力，计算时间和资源消耗方面寻求更有效的设计优化方法。当替代模型和最终过渡到HF模型的开关机制均被正确校准时，混合替代物优化保持了高效果，同时提供快速的设计评估。前馈神经网络（FNN）可以捕获高度非线性输入输出映射，从而为飞机绩效因素提供有效的替代物。但是，FNN通常无法概括分布（OOD）样本，这阻碍了它们在关键飞机设计优化中的采用。通过Smood，我们基于平滑度的分布检测方法，我们建议用优化的FNN替代物来编码一个依赖模型的OOD指标，以产生具有选择性但可信度的预测的值得信赖的替代模型。与常规的不确定性接地方法不同，Smood利用了HF模拟的固有平滑性特性，可以通过揭示其可疑敏感性有效地暴露OOD，从而避免对OOD样品的过度自信不确定性估计。通过使用SMOOD，仅将高风险的OOD输入转发到HF模型以进行重新评估，从而以低开销成本获得更准确的结果。研究了三个飞机性能模型。结果表明，基于FNN的代理在预测性能方面优于其高斯过程。此外，在所有研究案例中，Smood的确覆盖了85％的实际OOD。当Smood Plus FNN替代物被部署在混合替代优化设置中时，它们的错误率分别降低了34.65％和计算速度的降低率分别为58.36次。

简介：在房颤（AF）导管消融过程（CAP）期间记录了12条铅心电图（ECG）。如果没有长时间的随访评估AF复发（AFR），确定CAP是否成功并不容易。因此，AFR风险预测算法可以使CAP患者更好地管理。在这项研究中，我们从CAP前后记录的12铅ECG中提取功能，并训练AFR风险预测机学习模型。方法：从112例患者中提取前和后段段。该分析包括信号质量标准，心率变异性和由12铅ECG设计的形态生物标志物（总体804个功能）。在112名患者中，有43例AFR临床终点可用。这些用于使用前或后CAP特征来评估AFR风险预测的可行性。在嵌套的交叉验证框架内训练了一个随机的森林分类器。结果：发现36个特征在区分手术前和手术后具有统计学意义（n = 112）。对于分类，报告了接收器操作特性（AUROC）曲线下的区域，AUROC_PRE = 0.64，AUROC_POST = 0.74（n = 43）。讨论和结论：此初步分析表明AFR风险预测的可行性。这样的模型可用于改善盖帽管理。

在随机子集总和问题中，给定$ n $ i.i.d.随机变量$ x_1，...，x_n $，我们希望将[-1,1] $ in [-1,1] $的任何点$ z \作为合适子集的总和$ x_ {i_1（z）}，...，x_ {i_s（z）} $的$，最多$ \ varepsilon $。尽管有简单的陈述，但这个问题还是理论计算机科学和统计力学的基本兴趣。最近，它因其在人工神经网络理论中的影响而引起了人们的重新关注。该问题的一个明显的多维概括是考虑$ n $ i.i.d. \ $ d $ - 二维随机向量，目的是近似于[-1,1]^d $的每个点$ \ Mathbf {z} \。令人惊讶的是，在Lueker的1998年证明，在一维设置中，$ n = o（\ log \ frac 1 \ varepsilon）$ samples $ samples $ samples具有很高可能性的近似属性，在实现上述概括方面几乎没有进展。在这项工作中，我们证明，在$ d $ dimensions中，$ n = o（d^3 \ log \ frac 1 \ varepsilon \ cdot（\ log \ frac 1 \ frac 1 \ varepsilon + log d d））$ samples $ sample近似属性具有很高的概率。作为强调该结果潜在兴趣的应用程序，我们证明了最近提出的神经网络模型表现出\ emph {通用}：具有很高的概率，该模型可以在参数数量中近似多项式开销中的任何神经网络。