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。

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.

We present Habitat, a platform for research in embodied artificial intelligence (AI). Habitat enables training embodied agents (virtual robots) in highly efficient photorealistic 3D simulation. Specifically, Habitat consists of: (i) Habitat-Sim: a flexible, high-performance 3D simulator with configurable agents, sensors, and generic 3D dataset handling. Habitat-Sim is fast -when rendering a scene from Matterport3D, it achieves several thousand frames per second (fps) running single-threaded, and can reach over 10,000 fps multi-process on a single GPU. (ii) Habitat-API: a modular high-level library for end-toend development of embodied AI algorithms -defining tasks (e.g. navigation, instruction following, question answering), configuring, training, and benchmarking embodied agents.These large-scale engineering contributions enable us to answer scientific questions requiring experiments that were till now impracticable or 'merely' impractical. Specifically, in the context of point-goal navigation: (1) we revisit the comparison between learning and SLAM approaches from two recent works [20,16] and find evidence for the opposite conclusion -that learning outperforms SLAM if scaled to an order of magnitude more experience than previous investigations, and (2) we conduct the first cross-dataset generalization experiments {train, test} × {Matterport3D, Gibson} for multiple sensors {blind, RGB, RGBD, D} and find that only agents with depth (D) sensors generalize across datasets. We hope that our open-source platform and these findings will advance research in embodied AI.

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。

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。

最近的视听导航工作是无噪音音频环境中的单一静态声音，并努力推广到闻名声音。我们介绍了一种新型动态视听导航基准测试，其中一个体现的AI代理必须在存在分散的人和嘈杂的声音存在下在未映射的环境中捕获移动声源。我们提出了一种依赖于多模态架构的端到端增强学习方法，该方法依赖于融合来自双耳音频信号和空间占用映射的空间视听信息，以编码为我们的新的稳健导航策略进行编码所需的功能复杂的任务设置。我们展示了我们的方法优于当前的最先进状态，以更好地推广到闻名声音以及对嘈杂的3D扫描现实世界数据集副本和TASTPORT3D上的嘈杂情景更好地对嘈杂的情景进行了更好的稳健性，以实现静态和动态的视听导航基准。我们的小型基准将在http://dav-nav.cs.uni-freiburg.de提供。

We present a new AI task -Embodied Question Answering (EmbodiedQA) -where an agent is spawned at a random location in a 3D environment and asked a question ('What color is the car?'). In order to answer, the agent must first intelligently navigate to explore the environment, gather information through first-person (egocentric) vision, and then answer the question ('orange'). This challenging task requires a range of AI skills -active perception, language understanding, goal-driven navigation, commonsense reasoning, and grounding of language into actions. In this work, we develop the environments, end-to-end-trained reinforcement learning agents, and evaluation protocols for EmbodiedQA.

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。

主动同时定位和映射（SLAM）是规划和控制机器人运动以构建周围环境中最准确，最完整的模型的问题。自从三十多年前出现了积极感知的第一项基础工作以来，该领域在不同科学社区中受到了越来越多的关注。这带来了许多不同的方法和表述，并回顾了当前趋势，对于新的和经验丰富的研究人员来说都是非常有价值的。在这项工作中，我们在主动大满贯中调查了最先进的工作，并深入研究了仍然需要注意的公开挑战以满足现代应用程序的需求。为了实现现实世界的部署。在提供了历史观点之后，我们提出了一个统一的问题制定并审查经典解决方案方案，该方案将问题分解为三个阶段，以识别，选择和执行潜在的导航措施。然后，我们分析替代方法，包括基于深入强化学习的信念空间规划和现代技术，以及审查有关多机器人协调的相关工作。该手稿以讨论新的研究方向的讨论，解决可再现的研究，主动的空间感知和实际应用，以及其他主题。

视觉室内导航（VIN）任务已从数据驱动的机器学习社区中引起了人们的关注，尤其是在最近报告的基于学习方法的成功中。由于这项任务的先天复杂性，研究人员尝试从各种不同角度解决问题，其全部范围尚未在总体报告中捕获。这项调查首先总结了VIN任务的基于学习的方法的代表性工作，然后确定并讨论了阻碍VIN绩效的问题，并激发了值得探索社区的这些关键领域的未来研究。

我们介绍了互动室（Thor），这是一个视觉AI研究的框架，可在http://ai2thor.allenai.org上找到。AI2-这是由几乎逼真的3D室内场景组成的，在该场景中，AI代理可以在场景中导航并与对象进行交互以执行任务。AI2-这可以在许多不同的领域进行研究，包括但不限于深入强化学习，模仿学习，通过互动，计划，视觉问答答案，无监督的表示学习，对象检测和细分以及认知模型。AI2的目的是促进构建视觉上智能模型，并将研究推向该领域。

我们介绍了ThreedWorld（TDW），是交互式多模态物理模拟的平台。 TDW能够模拟高保真感官数据和富裕的3D环境中的移动代理和对象之间的物理交互。独特的属性包括：实时近光 - 真实图像渲染;对象和环境库，以及他们定制的例程;有效构建新环境课程的生成程序;高保真音频渲染;各种材料类型的现实物理相互作用，包括布料，液体和可变形物体;可定制的代理体现AI代理商;并支持与VR设备的人类交互。 TDW的API使多个代理能够在模拟中进行交互，并返回一系列表示世界状态的传感器和物理数据。我们在计算机视觉，机器学习和认知科学中的新兴的研究方向上提供了通过TDW的初始实验，包括多模态物理场景理解，物理动态预测，多代理交互，像孩子一样学习的模型，并注意研究人类和神经网络。

A robot that can carry out a natural-language instruction has been a dream since before the Jetsons cartoon series imagined a life of leisure mediated by a fleet of attentive robot helpers. It is a dream that remains stubbornly distant. However, recent advances in vision and language methods have made incredible progress in closely related areas. This is significant because a robot interpreting a naturallanguage navigation instruction on the basis of what it sees is carrying out a vision and language process that is similar to Visual Question Answering. Both tasks can be interpreted as visually grounded sequence-to-sequence translation problems, and many of the same methods are applicable. To enable and encourage the application of vision and language methods to the problem of interpreting visuallygrounded navigation instructions, we present the Matter-port3D Simulator -a large-scale reinforcement learning environment based on real imagery [11]. Using this simulator, which can in future support a range of embodied vision and language tasks, we provide the first benchmark dataset for visually-grounded natural language navigation in real buildings -the Room-to-Room (R2R) dataset 1 .1 https://bringmeaspoon.org Instruction: Head upstairs and walk past the piano through an archway directly in front. Turn right when the hallway ends at pictures and table. Wait by the moose antlers hanging on the wall.

我们介绍了栖息地2.0（H2.0），这是一个模拟平台，用于培训交互式3D环境和复杂物理的场景中的虚拟机器人。我们为体现的AI堆栈 - 数据，仿真和基准任务做出了全面的贡献。具体来说，我们提出：（i）复制：一个由艺术家的，带注释的，可重新配置的3D公寓（匹配真实空间）与铰接对象（例如可以打开/关闭的橱柜和抽屉）； （ii）H2.0：一个高性能物理学的3D模拟器，其速度超过8-GPU节点上的每秒25,000个模拟步骤（实时850x实时），代表先前工作的100倍加速；和（iii）家庭助理基准（HAB）：一套辅助机器人（整理房屋，准备杂货，设置餐桌）的一套常见任务，以测试一系列移动操作功能。这些大规模的工程贡献使我们能够系统地比较长期结构化任务中的大规模加固学习（RL）和经典的感官平面操作（SPA）管道，并重点是对新对象，容器和布局的概括。 。我们发现（1）与层次结构相比，（1）平面RL政策在HAB上挣扎； （2）具有独立技能的层次结构遭受“交接问题”的困扰，（3）水疗管道比RL政策更脆。

视听导航将视觉和听觉结合在未映射的环境中导航到声音源。虽然最近的方法已经证明了音频输入的好处，以检测和找到目标，他们专注于干净和静态的声源，并努力推广到闻名声音。在这项工作中，我们提出了新的动态视听导航基准，该基准测试基准测试，该基准要求在具有嘈杂和分散注意力的环境中捕捉环境中的移动声源。我们介绍了一种钢筋学习方法，用于为这些复杂设置学习强大的导航策略。为此，我们提出了一种架构，其融合空间特征空间中的视听信息，以学习本地地图和音频信号中固有的几何信息的相关性。我们展示了我们的方法在两个挑战的3D扫描的真实世界环境中，我们的方法始终如一地占据了所有权力，闻名声音和嘈杂环境的所有任务的大型余量。该基准测试是在http://dav-nav.cs.uni-freiburg.de上获得的。

Transformer, originally devised for natural language processing, has also attested significant success in computer vision. Thanks to its super expressive power, researchers are investigating ways to deploy transformers to reinforcement learning (RL) and the transformer-based models have manifested their potential in representative RL benchmarks. In this paper, we collect and dissect recent advances on transforming RL by transformer (transformer-based RL or TRL), in order to explore its development trajectory and future trend. We group existing developments in two categories: architecture enhancement and trajectory optimization, and examine the main applications of TRL in robotic manipulation, text-based games, navigation and autonomous driving. For architecture enhancement, these methods consider how to apply the powerful transformer structure to RL problems under the traditional RL framework, which model agents and environments much more precisely than deep RL methods, but they are still limited by the inherent defects of traditional RL algorithms, such as bootstrapping and "deadly triad". For trajectory optimization, these methods treat RL problems as sequence modeling and train a joint state-action model over entire trajectories under the behavior cloning framework, which are able to extract policies from static datasets and fully use the long-sequence modeling capability of the transformer. Given these advancements, extensions and challenges in TRL are reviewed and proposals about future direction are discussed. We hope that this survey can provide a detailed introduction to TRL and motivate future research in this rapidly developing field.

Generalisation to unseen contexts remains a challenge for embodied navigation agents. In the context of semantic audio-visual navigation (SAVi) tasks, the notion of generalisation should include both generalising to unseen indoor visual scenes as well as generalising to unheard sounding objects. However, previous SAVi task definitions do not include evaluation conditions on truly novel sounding objects, resorting instead to evaluating agents on unheard sound clips of known objects; meanwhile, previous SAVi methods do not include explicit mechanisms for incorporating domain knowledge about object and region semantics. These weaknesses limit the development and assessment of models' abilities to generalise their learned experience. In this work, we introduce the use of knowledge-driven scene priors in the semantic audio-visual embodied navigation task: we combine semantic information from our novel knowledge graph that encodes object-region relations, spatial knowledge from dual Graph Encoder Networks, and background knowledge from a series of pre-training tasks -- all within a reinforcement learning framework for audio-visual navigation. We also define a new audio-visual navigation sub-task, where agents are evaluated on novel sounding objects, as opposed to unheard clips of known objects. We show improvements over strong baselines in generalisation to unseen regions and novel sounding objects, within the Habitat-Matterport3D simulation environment, under the SoundSpaces task.

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.

Deep reinforcement learning is poised to revolutionise the field of AI and represents a step towards building autonomous systems with a higher level understanding of the visual world. Currently, deep learning is enabling reinforcement learning to scale to problems that were previously intractable, such as learning to play video games directly from pixels. Deep reinforcement learning algorithms are also applied to robotics, allowing control policies for robots to be learned directly from camera inputs in the real world. In this survey, we begin with an introduction to the general field of reinforcement learning, then progress to the main streams of value-based and policybased methods. Our survey will cover central algorithms in deep reinforcement learning, including the deep Q-network, trust region policy optimisation, and asynchronous advantage actor-critic. In parallel, we highlight the unique advantages of deep neural networks, focusing on visual understanding via reinforcement learning. To conclude, we describe several current areas of research within the field.

我们介绍了一个目标驱动的导航系统，以改善室内场景中的Fapless视觉导航。我们的方法在每次步骤中都将机器人和目标的多视图观察为输入，以提供将机器人移动到目标的一系列动作，而不依赖于运行时在运行时。通过优化包含三个关键设计的组合目标来了解该系统。首先，我们建议代理人在做出行动决定之前构建下一次观察。这是通过从专家演示中学习变分生成模块来实现的。然后，我们提出预测预先预测静态碰撞，作为辅助任务，以改善导航期间的安全性。此外，为了减轻终止动作预测的训练数据不平衡问题，我们还介绍了一个目标检查模块来区分与终止动作的增强导航策略。这三种建议的设计都有助于提高培训数据效率，静态冲突避免和导航泛化性能，从而产生了一种新颖的目标驱动的FLASES导航系统。通过对Turtlebot的实验，我们提供了证据表明我们的模型可以集成到机器人系统中并在现实世界中导航。视频和型号可以在补充材料中找到。