Learning generalizable insertion skills in a data-efficient manner has long been a challenge in the robot learning community. While the current state-of-the-art methods with reinforcement learning (RL) show promising performance in acquiring manipulation skills, the algorithms are data-hungry and hard to generalize. To overcome the issues, in this paper we present Prim-LAfD, a simple yet effective framework to learn and adapt primitive-based insertion skills from demonstrations. Prim-LAfD utilizes black-box function optimization to learn and adapt the primitive parameters leveraging prior experiences. Human demonstrations are modeled as dense rewards guiding parameter learning. We validate the effectiveness of the proposed method on eight peg-hole and connector-socket insertion tasks. The experimental results show that our proposed framework takes less than one hour to acquire the insertion skills and as few as fifteen minutes to adapt to an unseen insertion task on a physical robot.
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在本文中,我们讨论了通过模仿教授双人操作任务的框架。为此,我们提出了一种从人类示范中学习合规和接触良好的机器人行为的系统和算法。提出的系统结合了入学控制和机器学习的见解,以提取控制政策,这些政策可以(a)从时空和空间中恢复并适应各种干扰,同时(b)有效利用与环境的物理接触。我们使用现实世界中的插入任务证明了方法的有效性,该任务涉及操纵对象和插入钉之间的多个同时接触。我们还研究了为这种双人设置收集培训数据的有效方法。为此,我们进行了人类受试者的研究,并分析用户报告的努力和精神需求。我们的实验表明,尽管很难提供,但在遥控演示中可用的其他力/扭矩信息对于阶段估计和任务成功至关重要。最终,力/扭矩数据大大提高了操纵鲁棒性,从而在多点插入任务中获得了90%的成功率。可以在https://bimanualmanipulation.com/上找到代码和视频
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在过去的五十年中,刚体机器人技术的成熟领域已经成熟,对可变形物体的路线,计划和操纵最近已成为许多领域中更加未触及的研究领域,从外科机器人到工业组装和建筑。依赖于学习的隐式空间表示(例如,从示范方法学习)的可变形对象的路由方法使它们容易受到环境和特定设置的变化的影响。另一方面,完全将可变形对象的空间表示与路由和操纵的算法分开,通常使用独立于计划的表示方法,从而在高维空间中缓慢规划。本文提出了一种新颖的方法,用于路由可变形的一维对象(例如电线,电缆,绳索,缝合线,螺纹)。这种方法利用对象的紧凑表示形式,可以有效且快速的在线路由。空间表示基于空间的几何分解为凸子空间,从而导致将变形对象配置作为序列进行离散编码。通过这种配置,可以使用快速动态编程序列匹配方法来解决路由问题,该方法计算下一个路由移动。提出的方法将路由和有效的配置融合在一起,以改善计划时间。我们的仿真和实际实验显示了该方法正确地计算在子毫秒时间内的下一个操作操作,并完成各种路由和操纵任务。
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连续控制设置中的复杂顺序任务通常需要代理在其状态空间中成功遍历一组“窄段”。通过以样本有效的方式解决具有稀疏奖励的这些任务对现代钢筋(RL)构成了挑战,由于问题的相关的长地平性,并且在学习期间缺乏充足的正信号。已应用各种工具来解决这一挑战。当可用时,大型演示可以指导代理探索。后威尔同时释放不需要额外的信息来源。然而,现有的战略基于任务不可行的目标分布探索,这可以使长地平线的解决方案不切实际。在这项工作中,我们扩展了后视可释放的机制,以指导沿着一小组成功示范所暗示的特定任务特定分布的探索。我们评估了四个复杂,单身和双臂,机器人操纵任务的方法,对抗强合适的基线。该方法需要较少的演示来解决所有任务,并且达到明显更高的整体性能作为任务复杂性增加。最后,我们研究了提出的解决方案对输入表示质量和示范人数的鲁棒性。
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强化学习(RL)原则上可以让机器人自动适应新任务,但是当前的RL方法需要大量的试验来实现这一目标。在本文中,我们通过元学习的框架来快速适应新任务,该框架利用过去的任务学习适应了对工业插入任务的特定关注。快速适应至关重要,因为大量的机器人试验可能会损害硬件件。另外,在不同的插入应用之间的经验中,有效的适应性也可以在很大程度上彼此利用。在这种情况下,我们在应用元学习时解决了两个具体的挑战。首先,传统的元元算法需要冗长的在线元训练。 We show that this can be replaced with appropriately chosen offline data, resulting in an offline meta-RL method that only requires demonstrations and trials from each of the prior tasks, without the need to run costly meta-RL procedures online.其次,元RL方法可能无法推广到与元训练时间时看到的新任务太大的任务,这在高成功率至关重要的工业应用中构成了特定的挑战。我们通过将上下文元学习与直接在线填充结合结合来解决这一问题:如果新任务与先前数据中看到的任务相似,则可以立即适应上下文的元学习者,如果它太不同,它会逐渐通过Finetuning适应。我们表明,我们的方法能够快速适应各种不同的插入任务,成功率为100%仅使用从头开始学习任务所需的样本的一小部分。实验视频和详细信息可从https://sites.google.com/view/offline-metarl-insertion获得。
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Robots need to be able to adapt to unexpected changes in the environment such that they can autonomously succeed in their tasks. However, hand-designing feedback models for adaptation is tedious, if at all possible, making data-driven methods a promising alternative. In this paper we introduce a full framework for learning feedback models for reactive motion planning. Our pipeline starts by segmenting demonstrations of a complete task into motion primitives via a semi-automated segmentation algorithm. Then, given additional demonstrations of successful adaptation behaviors, we learn initial feedback models through learning from demonstrations. In the final phase, a sample-efficient reinforcement learning algorithm fine-tunes these feedback models for novel task settings through few real system interactions. We evaluate our approach on a real anthropomorphic robot in learning a tactile feedback task.
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Diversity Searcher is a tool originally developed to help analyse diversity in news media texts. It relies on a form of automated content analysis and thus rests on prior assumptions and depends on certain design choices related to diversity and fairness. One such design choice is the external knowledge source(s) used. In this article, we discuss implications that these sources can have on the results of content analysis. We compare two data sources that Diversity Searcher has worked with - DBpedia and Wikidata - with respect to their ontological coverage and diversity, and describe implications for the resulting analyses of text corpora. We describe a case study of the relative over- or under-representation of Belgian political parties between 1990 and 2020 in the English-language DBpedia, the Dutch-language DBpedia, and Wikidata, and highlight the many decisions needed with regard to the design of this data analysis and the assumptions behind it, as well as implications from the results. In particular, we came across a staggering over-representation of the political right in the English-language DBpedia.
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Artificial intelligence(AI) systems based on deep neural networks (DNNs) and machine learning (ML) algorithms are increasingly used to solve critical problems in bioinformatics, biomedical informatics, and precision medicine. However, complex DNN or ML models that are unavoidably opaque and perceived as black-box methods, may not be able to explain why and how they make certain decisions. Such black-box models are difficult to comprehend not only for targeted users and decision-makers but also for AI developers. Besides, in sensitive areas like healthcare, explainability and accountability are not only desirable properties of AI but also legal requirements -- especially when AI may have significant impacts on human lives. Explainable artificial intelligence (XAI) is an emerging field that aims to mitigate the opaqueness of black-box models and make it possible to interpret how AI systems make their decisions with transparency. An interpretable ML model can explain how it makes predictions and which factors affect the model's outcomes. The majority of state-of-the-art interpretable ML methods have been developed in a domain-agnostic way and originate from computer vision, automated reasoning, or even statistics. Many of these methods cannot be directly applied to bioinformatics problems, without prior customization, extension, and domain adoption. In this paper, we discuss the importance of explainability with a focus on bioinformatics. We analyse and comprehensively overview of model-specific and model-agnostic interpretable ML methods and tools. Via several case studies covering bioimaging, cancer genomics, and biomedical text mining, we show how bioinformatics research could benefit from XAI methods and how they could help improve decision fairness.
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Kernel machines have sustained continuous progress in the field of quantum chemistry. In particular, they have proven to be successful in the low-data regime of force field reconstruction. This is because many physical invariances and symmetries can be incorporated into the kernel function to compensate for much larger datasets. So far, the scalability of this approach has however been hindered by its cubical runtime in the number of training points. While it is known, that iterative Krylov subspace solvers can overcome these burdens, they crucially rely on effective preconditioners, which are elusive in practice. Practical preconditioners need to be computationally efficient and numerically robust at the same time. Here, we consider the broad class of Nystr\"om-type methods to construct preconditioners based on successively more sophisticated low-rank approximations of the original kernel matrix, each of which provides a different set of computational trade-offs. All considered methods estimate the relevant subspace spanned by the kernel matrix columns using different strategies to identify a representative set of inducing points. Our comprehensive study covers the full spectrum of approaches, starting from naive random sampling to leverage score estimates and incomplete Cholesky factorizations, up to exact SVD decompositions.
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We present an automatic method for annotating images of indoor scenes with the CAD models of the objects by relying on RGB-D scans. Through a visual evaluation by 3D experts, we show that our method retrieves annotations that are at least as accurate as manual annotations, and can thus be used as ground truth without the burden of manually annotating 3D data. We do this using an analysis-by-synthesis approach, which compares renderings of the CAD models with the captured scene. We introduce a 'cloning procedure' that identifies objects that have the same geometry, to annotate these objects with the same CAD models. This allows us to obtain complete annotations for the ScanNet dataset and the recent ARKitScenes dataset.
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