A household robot should be able to navigate to target locations without requiring users to first annotate everything in their home. Current approaches to this object navigation challenge do not test on real robots and rely on expensive semantically labeled 3D meshes. In this work, our aim is an agent that builds self-supervised models of the world via exploration, the same as a child might. We propose an end-to-end self-supervised embodied agent that leverages exploration to train a semantic segmentation model of 3D objects, and uses those representations to learn an object navigation policy purely from self-labeled 3D meshes. The key insight is that embodied agents can leverage location consistency as a supervision signal - collecting images from different views/angles and applying contrastive learning to fine-tune a semantic segmentation model. In our experiments, we observe that our framework performs better than other self-supervised baselines and competitively with supervised baselines, in both simulation and when deployed in real houses.

Semantic navigation is necessary to deploy mobile robots in uncontrolled environments like our homes, schools, and hospitals. Many learning-based approaches have been proposed in response to the lack of semantic understanding of the classical pipeline for spatial navigation, which builds a geometric map using depth sensors and plans to reach point goals. Broadly, end-to-end learning approaches reactively map sensor inputs to actions with deep neural networks, while modular learning approaches enrich the classical pipeline with learning-based semantic sensing and exploration. But learned visual navigation policies have predominantly been evaluated in simulation. How well do different classes of methods work on a robot? We present a large-scale empirical study of semantic visual navigation methods comparing representative methods from classical, modular, and end-to-end learning approaches across six homes with no prior experience, maps, or instrumentation. We find that modular learning works well in the real world, attaining a 90% success rate. In contrast, end-to-end learning does not, dropping from 77% simulation to 23% real-world success rate due to a large image domain gap between simulation and reality. For practitioners, we show that modular learning is a reliable approach to navigate to objects: modularity and abstraction in policy design enable Sim-to-Real transfer. For researchers, we identify two key issues that prevent today's simulators from being reliable evaluation benchmarks - (A) a large Sim-to-Real gap in images and (B) a disconnect between simulation and real-world error modes - and propose concrete steps forward.

We present a retrospective on the state of Embodied AI research. Our analysis focuses on 13 challenges presented at the Embodied AI Workshop at CVPR. These challenges are grouped into three themes: (1) visual navigation, (2) rearrangement, and (3) embodied vision-and-language. We discuss the dominant datasets within each theme, evaluation metrics for the challenges, and the performance of state-of-the-art models. We highlight commonalities between top approaches to the challenges and identify potential future directions for Embodied AI research.

在本文中，我们探索如何在互联网图像的数据和型号上构建，并使用它们适应机器人视觉，而无需任何额外的标签。我们提出了一个叫做自我监督体现的主动学习（密封）的框架。它利用互联网图像培训的感知模型来学习主动探索政策。通过3D一致性标记此探索策略收集的观察结果，并用于改善感知模型。我们构建并利用3D语义地图以完全自我监督的方式学习动作和感知。语义地图用于计算用于培训勘探政策的内在动机奖励，并使用时空3D一致性和标签传播标记代理观察。我们证明了密封框架可用于关闭动作 - 感知循环：通过在训练环境中移动，改善预读的感知模型的对象检测和实例分割性能，并且可以使用改进的感知模型来改善对象目标导航。

Efficient ObjectGoal navigation (ObjectNav) in novel environments requires an understanding of the spatial and semantic regularities in environment layouts. In this work, we present a straightforward method for learning these regularities by predicting the locations of unobserved objects from incomplete semantic maps. Our method differs from previous prediction-based navigation methods, such as frontier potential prediction or egocentric map completion, by directly predicting unseen targets while leveraging the global context from all previously explored areas. Our prediction model is lightweight and can be trained in a supervised manner using a relatively small amount of passively collected data. Once trained, the model can be incorporated into a modular pipeline for ObjectNav without the need for any reinforcement learning. We validate the effectiveness of our method on the HM3D and MP3D ObjectNav datasets. We find that it achieves the state-of-the-art on both datasets, despite not using any additional data for training.

Training embodied agents in simulation has become mainstream for the embodied AI community. However, these agents often struggle when deployed in the physical world due to their inability to generalize to real-world environments. In this paper, we present Phone2Proc, a method that uses a 10-minute phone scan and conditional procedural generation to create a distribution of training scenes that are semantically similar to the target environment. The generated scenes are conditioned on the wall layout and arrangement of large objects from the scan, while also sampling lighting, clutter, surface textures, and instances of smaller objects with randomized placement and materials. Leveraging just a simple RGB camera, training with Phone2Proc shows massive improvements from 34.7% to 70.7% success rate in sim-to-real ObjectNav performance across a test suite of over 200 trials in diverse real-world environments, including homes, offices, and RoboTHOR. Furthermore, Phone2Proc's diverse distribution of generated scenes makes agents remarkably robust to changes in the real world, such as human movement, object rearrangement, lighting changes, or clutter.

对象看起来和声音的方式提供了对其物理特性的互补反射。在许多设置中，视觉和试听的线索都异步到达，但必须集成，就像我们听到一个物体掉落在地板上，然后必须找到它时。在本文中，我们介绍了一个设置，用于研究3D虚拟环境中的多模式对象定位。一个物体在房间的某个地方掉落。配备了摄像头和麦克风的具体机器人剂必须通过将音频和视觉信号与知识的基础物理学结合来确定已删除的对象以及位置。为了研究此问题，我们生成了一个大规模数据集 - 倒下的对象数据集 - 其中包括64个房间中30个物理对象类别的8000个实例。该数据集使用Threedworld平台，该平台可以模拟基于物理的影响声音和在影片设置中对象之间的复杂物理交互。作为解决这一挑战的第一步，我们基于模仿学习，强化学习和模块化计划，开发了一组具体的代理基线，并对这项新任务的挑战进行了深入的分析。

对象目标导航的最新方法依赖于增强学习，通常需要大量的计算资源和学习时间。我们提出了使用无互动学习（PONI）的对象导航的潜在功能，这是一种模块化方法，可以散布“在哪里看？”的技能？对于对象和“如何导航到（x，y）？”。我们的主要见解是“在哪里看？”可以纯粹将其视为感知问题，而没有环境相互作用就可以学习。为了解决这个问题，我们提出了一个网络，该网络可以预测两个在语义图上的互补电位功能，并使用它们来决定在哪里寻找看不见的对象。我们使用在自上而下的语义图的被动数据集上使用受监督的学习来训练潜在的功能网络，并将其集成到模块化框架中以执行对象目标导航。 Gibson和MatterPort3D的实验表明，我们的方法可实现对象目标导航的最新方法，同时减少培训计算成本高达1,600倍。可以使用代码和预训练的模型：https：//vision.cs.utexas.edu/projects/poni/

我们提出了一种可扩展的方法，用于学习开放世界对象目标导航（ObjectNAV） - 要求虚拟机器人（代理）在未探索的环境中找到对象的任何实例（例如，“查找接收器”）。我们的方法完全是零拍的 - 即，它不需要任何形式的objectNav奖励或演示。取而代之的是，我们训练图像目标导航（ImagenAv）任务，在该任务中，代理在其中找到了捕获图片（即目标图像）的位置。具体而言，我们将目标图像编码为多模式的语义嵌入空间，以在未注释的3D环境（例如HM3D）中以大规模训练语义目标导航（Senanticnav）代理。训练后，可以指示Semanticnav代理查找以自由形式的自然语言描述的对象（例如，“接收器”，“浴室水槽”等），通过将语言目标投射到相同的多模式，语义嵌入空间中。结果，我们的方法启用了开放世界的ObjectNAV。我们在三个ObjectNAV数据集（Gibson，HM3D和MP3D）上广泛评估了我们的代理商，并观察到成功的4.2％-20.0％的绝对改进。作为参考，这些收益与2020年至2021年Objectnav挑战赛竞争对手之间成功的5％改善相似或更好。在开放世界的环境中，我们发现我们的代理商可以概括为明确提到的房间（例如，“找到厨房水槽”）的复合说明，并且何时可以推断目标室（例如，”找到水槽和炉子”）。

第一人称视频在其持续环境的背景下突出了摄影师的活动。但是，当前的视频理解方法是从短视频剪辑中的视觉特征的原因，这些视频片段与基础物理空间分离，只捕获直接看到的东西。我们提出了一种方法，该方法通过学习摄影师（潜在看不见的）本地环境来促进以人为中心的环境的了解来链接以自我为中心的视频和摄像机随着时间的推移而张开。我们使用来自模拟的3D环境中的代理商的视频进行训练，在该环境中，环境完全可以观察到，并在看不见的环境的房屋旅行的真实视频中对其进行测试。我们表明，通过将视频接地在其物理环境中，我们的模型超过了传统的场景分类模型，可以预测摄影师所处的哪个房间（其中帧级信息不足），并且可以利用这种基础来定位与环境相对应的视频瞬间 - 中心查询，优于先验方法。项目页面：http：//vision.cs.utexas.edu/projects/ego-scene-context/

从“Internet AI”的时代到“体现AI”的时代，AI算法和代理商出现了一个新兴范式转变，其中不再从主要来自Internet策划的图像，视频或文本的数据集。相反，他们通过与与人类类似的Enocentric感知来通过与其环境的互动学习。因此，对体现AI模拟器的需求存在大幅增长，以支持各种体现的AI研究任务。这种越来越多的体现AI兴趣是有利于对人工综合情报（AGI）的更大追求，但对这一领域并无一直存在当代和全面的调查。本文旨在向体现AI领域提供百科全书的调查，从其模拟器到其研究。通过使用我们提出的七种功能评估九个当前体现的AI模拟器，旨在了解模拟器，以其在体现AI研究和其局限性中使用。最后，本文调查了体现AI - 视觉探索，视觉导航和体现问题的三个主要研究任务（QA），涵盖了最先进的方法，评估指标和数据集。最后，随着通过测量该领域的新见解，本文将为仿真器 - 任务选择和建议提供关于该领域的未来方向的建议。

In recent years several learning approaches to point goal navigation in previously unseen environments have been proposed. They vary in the representations of the environments, problem decomposition, and experimental evaluation. In this work, we compare the state-of-the-art Deep Reinforcement Learning based approaches with Partially Observable Markov Decision Process (POMDP) formulation of the point goal navigation problem. We adapt the (POMDP) sub-goal framework proposed by [1] and modify the component that estimates frontier properties by using partial semantic maps of indoor scenes built from images' semantic segmentation. In addition to the well-known completeness of the model-based approach, we demonstrate that it is robust and efficient in that it leverages informative, learned properties of the frontiers compared to an optimistic frontier-based planner. We also demonstrate its data efficiency compared to the end-to-end deep reinforcement learning approaches. We compare our results against an optimistic planner, ANS and DD-PPO on Matterport3D dataset using the Habitat Simulator. We show comparable, though slightly worse performance than the SOTA DD-PPO approach, yet with far fewer data.

Training effective embodied AI agents often involves manual reward engineering, expert imitation, specialized components such as maps, or leveraging additional sensors for depth and localization. Another approach is to use neural architectures alongside self-supervised objectives which encourage better representation learning. In practice, there are few guarantees that these self-supervised objectives encode task-relevant information. We propose the Scene Graph Contrastive (SGC) loss, which uses scene graphs as general-purpose, training-only, supervisory signals. The SGC loss does away with explicit graph decoding and instead uses contrastive learning to align an agent's representation with a rich graphical encoding of its environment. The SGC loss is generally applicable, simple to implement, and encourages representations that encode objects' semantics, relationships, and history. Using the SGC loss, we attain significant gains on three embodied tasks: Object Navigation, Multi-Object Navigation, and Arm Point Navigation. Finally, we present studies and analyses which demonstrate the ability of our trained representation to encode semantic cues about the environment.

Object goal navigation (ObjectNav) in unseen environments is a fundamental task for Embodied AI. Agents in existing works learn ObjectNav policies based on 2D maps, scene graphs, or image sequences. Considering this task happens in 3D space, a 3D-aware agent can advance its ObjectNav capability via learning from fine-grained spatial information. However, leveraging 3D scene representation can be prohibitively unpractical for policy learning in this floor-level task, due to low sample efficiency and expensive computational cost. In this work, we propose a framework for the challenging 3D-aware ObjectNav based on two straightforward sub-policies. The two sub-polices, namely corner-guided exploration policy and category-aware identification policy, simultaneously perform by utilizing online fused 3D points as observation. Through extensive experiments, we show that this framework can dramatically improve the performance in ObjectNav through learning from 3D scene representation. Our framework achieves the best performance among all modular-based methods on the Matterport3D and Gibson datasets, while requiring (up to 30x) less computational cost for training.

这项工作研究了图像目标导航问题，需要通过真正拥挤的环境引导具有嘈杂传感器和控制的机器人。最近的富有成效的方法依赖于深度加强学习，并学习模拟环境中的导航政策，这些环境比真实环境更简单。直接将这些训练有素的策略转移到真正的环境可能非常具有挑战性甚至危险。我们用由四个解耦模块组成的分层导航方法来解决这个问题。第一模块在机器人导航期间维护障碍物映射。第二个将定期预测实时地图上的长期目标。第三个计划碰撞命令集以导航到长期目标，而最终模块将机器人正确靠近目标图像。四个模块是单独开发的，以适应真实拥挤的情景中的图像目标导航。此外，分层分解对导航目标规划，碰撞避免和导航结束预测的学习进行了解耦，这在导航训练期间减少了搜索空间，并有助于改善以前看不见的真实场景的概括。我们通过移动机器人评估模拟器和现实世界中的方法。结果表明，我们的方法优于多种导航基线，可以在这些方案中成功实现导航任务。

For robots to be generally useful, they must be able to find arbitrary objects described by people (i.e., be language-driven) even without expensive navigation training on in-domain data (i.e., perform zero-shot inference). We explore these capabilities in a unified setting: language-driven zero-shot object navigation (L-ZSON). Inspired by the recent success of open-vocabulary models for image classification, we investigate a straightforward framework, CLIP on Wheels (CoW), to adapt open-vocabulary models to this task without fine-tuning. To better evaluate L-ZSON, we introduce the Pasture benchmark, which considers finding uncommon objects, objects described by spatial and appearance attributes, and hidden objects described relative to visible objects. We conduct an in-depth empirical study by directly deploying 21 CoW baselines across Habitat, RoboTHOR, and Pasture. In total, we evaluate over 90k navigation episodes and find that (1) CoW baselines often struggle to leverage language descriptions, but are proficient at finding uncommon objects. (2) A simple CoW, with CLIP-based object localization and classical exploration -- and no additional training -- matches the navigation efficiency of a state-of-the-art ZSON method trained for 500M steps on Habitat MP3D data. This same CoW provides a 15.6 percentage point improvement in success over a state-of-the-art RoboTHOR ZSON model.

这项工作提出了一种体现的代理，可以以完全自主的方式将其语义分割网络调整到新的室内环境中。由于语义分割网络无法很好地推广到看不见的环境，因此代理会收集新环境的图像，然后将其用于自我监督的域适应性。我们将其作为一个有益的路径计划问题提出，并提出一种新的信息增益，该信息利用从语义模型中提取的不确定性来安全地收集相关数据。随着域的适应性的进展，这些不确定性会随着时间的推移而发生变化，并且我们系统的快速学习反馈驱使代理收集不同的数据。实验表明，与勘探目标相比，我们的方法更快地适应了新环境，最终性能更高，并且可以成功部署到物理机器人上的现实环境中。

移动机器人的视觉导航经典通过SLAM加上最佳规划，最近通过实现作为深网络的端到端培训。虽然前者通常仅限于航点计划，但即使在真实的物理环境中已经证明了它们的效率，后一种解决方案最常用于模拟中，但已被证明能够学习更复杂的视觉推理，涉及复杂的语义规则。通过实际机器人在物理环境中导航仍然是一个开放问题。端到端的培训方法仅在模拟中进行了彻底测试，实验涉及实际机器人的实际机器人在简化的实验室条件下限制为罕见的性能评估。在这项工作中，我们对真实物理代理的性能和推理能力进行了深入研究，在模拟中培训并部署到两个不同的物理环境。除了基准测试之外，我们提供了对不同条件下不同代理商培训的泛化能力的见解。我们可视化传感器使用以及不同类型信号的重要性。我们展示了，对于Pointgoal Task，一个代理在各种任务上进行预先培训，并在目标环境的模拟版本上进行微调，可以达到竞争性能，而无需建模任何SIM2重传，即通过直接从仿真部署培训的代理即可一个真正的物理机器人。

Developing robots that are capable of many skills and generalization to unseen scenarios requires progress on two fronts: efficient collection of large and diverse datasets, and training of high-capacity policies on the collected data. While large datasets have propelled progress in other fields like computer vision and natural language processing, collecting data of comparable scale is particularly challenging for physical systems like robotics. In this work, we propose a framework to bridge this gap and better scale up robot learning, under the lens of multi-task, multi-scene robot manipulation in kitchen environments. Our framework, named CACTI, has four stages that separately handle data collection, data augmentation, visual representation learning, and imitation policy training. In the CACTI framework, we highlight the benefit of adapting state-of-the-art models for image generation as part of the augmentation stage, and the significant improvement of training efficiency by using pretrained out-of-domain visual representations at the compression stage. Experimentally, we demonstrate that 1) on a real robot setup, CACTI enables efficient training of a single policy capable of 10 manipulation tasks involving kitchen objects, and robust to varying layouts of distractor objects; 2) in a simulated kitchen environment, CACTI trains a single policy on 18 semantic tasks across up to 50 layout variations per task. The simulation task benchmark and augmented datasets in both real and simulated environments will be released to facilitate future research.

在视觉和语言导航（VLN）中，按照自然语言指令在现实的3D环境中需要具体的代理。现有VLN方法的一个主要瓶颈是缺乏足够的培训数据，从而导致对看不见的环境的概括不令人满意。虽然通常会手动收集VLN数据，但这种方法很昂贵，并且可以防止可扩展性。在这项工作中，我们通过建议从HM3D自动创建900个未标记的3D建筑物的大规模VLN数据集来解决数据稀缺问题。我们为每个建筑物生成一个导航图，并通过交叉视图一致性从2D传输对象预测，从2D传输伪3D对象标签。然后，我们使用伪对象标签来微调一个预处理的语言模型，作为减轻教学生成中跨模式差距的提示。在导航环境和说明方面，我们生成的HM3D-AUTOVLN数据集是比现有VLN数据集大的数量级。我们通过实验表明，HM3D-AUTOVLN显着提高了所得VLN模型的概括能力。在SPL指标上，我们的方法分别在Reverie和DataSet的看不见的验证分裂分别对艺术的状态提高了7.1％和8.1％。