In this paper a global reactive motion planning framework for robotic manipulators in complex dynamic environments is presented. In particular, the circular field predictions (CFP) planner from Becker et al. (2021) is extended to ensure obstacle avoidance of the whole structure of a robotic manipulator. Towards this end, a motion planning framework is developed that leverages global information about promising avoidance directions from arbitrary configuration space motion planners, resulting in improved global trajectories while reactively avoiding dynamic obstacles and decreasing the required computational power. The resulting motion planning framework is tested in multiple simulations with complex and dynamic obstacles and demonstrates great potential compared to existing motion planning approaches.

Humans intuitively solve tasks in versatile ways, varying their behavior in terms of trajectory-based planning and for individual steps. Thus, they can easily generalize and adapt to new and changing environments. Current Imitation Learning algorithms often only consider unimodal expert demonstrations and act in a state-action-based setting, making it difficult for them to imitate human behavior in case of versatile demonstrations. Instead, we combine a mixture of movement primitives with a distribution matching objective to learn versatile behaviors that match the expert's behavior and versatility. To facilitate generalization to novel task configurations, we do not directly match the agent's and expert's trajectory distributions but rather work with concise geometric descriptors which generalize well to unseen task configurations. We empirically validate our method on various robot tasks using versatile human demonstrations and compare to imitation learning algorithms in a state-action setting as well as a trajectory-based setting. We find that the geometric descriptors greatly help in generalizing to new task configurations and that combining them with our distribution-matching objective is crucial for representing and reproducing versatile behavior.

复发状态空间模型（RSSM）是时间序列数据和系统标识中学习模式的高度表达模型。但是，这些模型假定动力学是固定和不变的，在现实世界中，这种动力学很少发生。许多控制应用程序通常表现出具有相似但不相同动力学的任务，这些任务可以建模为潜在变量。我们介绍了隐藏的参数复发状态空间模型（HIP-RSSM），该框架为具有低维的潜在因素集的相关动态系统的家庭参数。我们提出了一种对这种高斯图形模型的学习和执行推理的简单有效方法，该模型避免了诸如变异推理之类的近似值。我们表明，HIP-RSSM在现实世界系统和仿真上的几个挑战性机器人基准上都优于RSSM和竞争性的多任务模型。

机器人的长期愿景是装备机器人，技能与人类的多功能性和精度相匹配。例如，在播放乒乓球时，机器人应该能够以各种方式返回球，同时精确地将球放置在所需位置。模拟这种多功能行为的常见方法是使用专家（MOE）模型的混合，其中每个专家是一个上下文运动原语。然而，由于大多数目标强迫模型涵盖整个上下文空间，因此学习此类MOS是具有挑战性的，这可以防止基元的专业化导致相当低质量的组件。从最大熵增强学习（RL）开始，我们将目标分解为优化每个混合组件的个体下限。此外，我们通过允许组件专注于本地上下文区域来介绍课程，使模型能够学习高度准确的技能表示。为此，我们使用与专家原语共同调整的本地上下文分布。我们的下限主张迭代添加新组件，其中新组件将集中在当前MOE不涵盖的本地上下文区域上。这种本地和增量学习导致高精度和多功能性的模块化MOE模型，其中可以通过在飞行中添加更多组件来缩放两个属性。我们通过广泛的消融和两个具有挑战性的模拟机器人技能学习任务来证明这一点。我们将我们的绩效与Live和Hireps进行了比较，这是一个已知的分层政策搜索方法，用于学习各种技能。

预测驾驶行为或其他传感器测量是自主驱动系统的基本组成部分。通常是现实世界多变量序列数据难以模拟，因为潜在的动态是非线性的，并且观察是嘈杂的。此外，驾驶数据通常可以在分布中多传，这意味着存在不同的预测，但平均可能会损害模型性能。为解决此问题，我们提出了对非线性和多模态时间序列数据的有效推理和预测的转换复发性卡尔曼网络（SRKN）。该模型在几个卡尔曼滤波器之间切换，该滤波器以分解潜在状态模拟动态的不同方面。我们经验测试了在玩具数据集上产生的可扩展和可解释的深度状态空间模型，并在波尔图中的出租车实际驾驶数据。在所有情况下，该模型可以捕获数据中动态的多模式性质。

逆钢筋学习从专家演示中获取奖励功能，旨在编码专家的行为和意图。目前的方法通常用生成和Uni-Modal模型来执行此操作，这意味着它们编码单个行为。在常见的环境中，在有问题的各种解决方案中，专家显示多功能行为，这严重限制了这些方法的泛化能力。我们提出了一种新颖的逆钢筋学习方法，通过将恢复的奖励作为迭代训练的鉴别者的总和制定回收的奖励来提出克服这些问题。我们展示了我们的方法能够恢复一般，高质量的奖励功能，并产生与专为多才多艺行为设计的行为克隆方法相同的质量的政策。

The release of ChatGPT, a language model capable of generating text that appears human-like and authentic, has gained significant attention beyond the research community. We expect that the convincing performance of ChatGPT incentivizes users to apply it to a variety of downstream tasks, including prompting the model to simplify their own medical reports. To investigate this phenomenon, we conducted an exploratory case study. In a questionnaire, we asked 15 radiologists to assess the quality of radiology reports simplified by ChatGPT. Most radiologists agreed that the simplified reports were factually correct, complete, and not potentially harmful to the patient. Nevertheless, instances of incorrect statements, missed key medical findings, and potentially harmful passages were reported. While further studies are needed, the initial insights of this study indicate a great potential in using large language models like ChatGPT to improve patient-centered care in radiology and other medical domains.

We consider a semi-supervised $k$-clustering problem where information is available on whether pairs of objects are in the same or in different clusters. This information is either available with certainty or with a limited level of confidence. We introduce the PCCC algorithm, which iteratively assigns objects to clusters while accounting for the information provided on the pairs of objects. Our algorithm can include relationships as hard constraints that are guaranteed to be satisfied or as soft constraints that can be violated subject to a penalty. This flexibility distinguishes our algorithm from the state-of-the-art in which all pairwise constraints are either considered hard, or all are considered soft. Unlike existing algorithms, our algorithm scales to large-scale instances with up to 60,000 objects, 100 clusters, and millions of cannot-link constraints (which are the most challenging constraints to incorporate). We compare the PCCC algorithm with state-of-the-art approaches in an extensive computational study. Even though the PCCC algorithm is more general than the state-of-the-art approaches in its applicability, it outperforms the state-of-the-art approaches on instances with all hard constraints or all soft constraints both in terms of running time and various metrics of solution quality. The source code of the PCCC algorithm is publicly available on GitHub.

Linear partial differential equations (PDEs) are an important, widely applied class of mechanistic models, describing physical processes such as heat transfer, electromagnetism, and wave propagation. In practice, specialized numerical methods based on discretization are used to solve PDEs. They generally use an estimate of the unknown model parameters and, if available, physical measurements for initialization. Such solvers are often embedded into larger scientific models or analyses with a downstream application such that error quantification plays a key role. However, by entirely ignoring parameter and measurement uncertainty, classical PDE solvers may fail to produce consistent estimates of their inherent approximation error. In this work, we approach this problem in a principled fashion by interpreting solving linear PDEs as physics-informed Gaussian process (GP) regression. Our framework is based on a key generalization of a widely-applied theorem for conditioning GPs on a finite number of direct observations to observations made via an arbitrary bounded linear operator. Crucially, this probabilistic viewpoint allows to (1) quantify the inherent discretization error; (2) propagate uncertainty about the model parameters to the solution; and (3) condition on noisy measurements. Demonstrating the strength of this formulation, we prove that it strictly generalizes methods of weighted residuals, a central class of PDE solvers including collocation, finite volume, pseudospectral, and (generalized) Galerkin methods such as finite element and spectral methods. This class can thus be directly equipped with a structured error estimate and the capability to incorporate uncertain model parameters and observations. In summary, our results enable the seamless integration of mechanistic models as modular building blocks into probabilistic models.

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.