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2020 IEEE International Conference on Robotics and Automation (ICRA)最新文献

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Environment Prediction from Sparse Samples for Robotic Information Gathering 基于稀疏样本的机器人信息采集环境预测
Pub Date : 2020-05-01 DOI: 10.1109/ICRA40945.2020.9197263
Jeffrey A. Caley, Geoffrey A. Hollinger
Robots often require a model of their environment to make informed decisions. In unknown environments, the ability to infer the value of a data field from a limited number of samples is essential to many robotics applications. In this work, we propose a neural network architecture to model these spatially correlated data fields based on a limited number of spatially continuous samples. Additionally, we provide a method based on biased loss functions to suggest future areas of exploration to minimize reconstruction error. We run simulated robotic information gathering trials on both the MNIST hand written digits dataset and a Regional Ocean Modeling System (ROMS) ocean dataset for ocean monitoring. Our method outperforms Gaussian process regression in both environments for modeling the data field and action selection.
机器人通常需要一个环境模型来做出明智的决定。在未知环境中,从有限数量的样本中推断数据字段值的能力对许多机器人应用程序至关重要。在这项工作中,我们提出了一个基于有限数量的空间连续样本的神经网络架构来建模这些空间相关的数据场。此外,我们提供了一种基于偏差损失函数的方法来建议未来的勘探区域,以最大限度地减少重建误差。我们在MNIST手写数字数据集和区域海洋建模系统(ROMS)海洋数据集上进行了模拟机器人信息收集试验,用于海洋监测。我们的方法在数据域建模和动作选择两种环境中都优于高斯过程回归。
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引用次数: 5
A Dynamical System Approach for Adaptive Grasping, Navigation and Co-Manipulation with Humanoid Robots 类人机器人自适应抓取、导航与协同操作的动态系统方法
Pub Date : 2020-05-01 DOI: 10.1109/ICRA40945.2020.9197038
Nadia Figueroa, Salman Faraji, M. Koptev, A. Billard
In this paper, we present an integrated approach that provides compliant control of an iCub humanoid robot and adaptive reaching, grasping, navigating and co-manipulating capabilities. We use state-dependent dynamical systems (DS) to (i) coordinate and drive the robots hands (in both position and orientation) to grasp an object using an intermediate virtual object, and (ii) drive the robot's base while walking/navigating. The use of DS as motion generators allows us to adapt smoothly as the object moves and to re-plan on-line motion of the arms and body to reach the object's new location. The desired motion generated by the DS are used in combination with a whole-body compliant control strategy that absorbs perturbations while walking and offers compliant behaviors for grasping and manipulation tasks. Further, the desired dynamics for the arm and body can be learned from demonstrations. By integrating these components, we achieve unprecedented adaptive behaviors for whole body manipulation. We showcase this in simulations and real-world experiments where iCub robots (i) walk-to-grasp objects, (ii) follow a human (or another iCub) through interaction and (iii) learn to navigate or comanipulate an object from human guided demonstrations; whilst being robust to changing targets and perturbations.
在本文中,我们提出了一种集成的方法,提供了iCub人形机器人的柔性控制和自适应的到达、抓取、导航和协同操作能力。我们使用状态依赖的动力系统(DS)来(i)协调和驱动机器人的手(在位置和方向上)使用中间虚拟物体来抓取物体,以及(ii)在行走/导航时驱动机器人的基座。使用DS作为运动发生器使我们能够顺利地适应物体的移动,并重新规划手臂和身体的在线运动,以达到物体的新位置。由DS产生的期望运动与全身柔性控制策略结合使用,该策略可以吸收行走时的扰动,并为抓取和操作任务提供柔性行为。此外,手臂和身体所需的动力学可以从演示中学习。通过整合这些组件,我们实现了前所未有的全身操作自适应行为。我们在模拟和现实世界的实验中展示了这一点,其中iCub机器人(i)走到抓取对象,(ii)通过交互跟随人类(或另一个iCub), (iii)学习导航或操纵人类引导演示的对象;同时对变化的目标和扰动具有鲁棒性。
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引用次数: 12
Cooperative Multi-Robot Navigation in Dynamic Environment with Deep Reinforcement Learning 基于深度强化学习的动态环境下多机器人协同导航
Pub Date : 2020-05-01 DOI: 10.1109/ICRA40945.2020.9197209
Ruihua Han, Shengduo Chen, Qi Hao
The challenges of multi-robot navigation in dynamic environments lie in uncertainties in obstacle complexities, partially observation of robots, and policy implementation from simulations to the real world. This paper presents a cooperative approach to address the multi-robot navigation problem (MRNP) under dynamic environments using a deep reinforcement learning (DRL) framework, which can help multiple robots jointly achieve optimal paths despite a certain degree of obstacle complexities. The novelty of this work includes threefold: (1) developing a cooperative architecture that robots can exchange information with each other to select the optimal target locations; (2) developing a DRL based framework which can learn a navigation policy to generate the optimal paths for multiple robots; (3) developing a training mechanism based on dynamics randomization which can make the policy generalized and achieve the maximum performance in the real world. The method is tested with Gazebo simulations and 4 differential drive robots. Both simulation and experiment results validate the superior performance of the proposed method in terms of success rate and travel time when compared with the other state-of-art technologies.
动态环境下多机器人导航的挑战在于障碍复杂性的不确定性、机器人的部分可观察性以及从模拟到现实世界的策略实施。本文提出了一种基于深度强化学习(DRL)框架的动态环境下多机器人导航问题(MRNP)的协作方法,该方法可以帮助多个机器人在一定程度的障碍物复杂性下共同实现最优路径。该工作的新颖之处包括三个方面:(1)开发了一种协作架构,使机器人能够相互交换信息以选择最优目标位置;(2)开发基于DRL的导航策略学习框架,生成多个机器人的最优路径;(3)开发一种基于动态随机化的训练机制,使策略泛化并在现实世界中达到最大性能。通过Gazebo仿真和4台差动驱动机器人对该方法进行了验证。仿真和实验结果都证明了该方法在成功率和行程时间方面优于其他先进技术。
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引用次数: 21
Mechanically Programmed Miniature Origami Grippers 机械编程微型折纸手
Pub Date : 2020-05-01 DOI: 10.1109/ICRA40945.2020.9196545
Alec Orlofsky, Chang Liu, S. Kamrava, A. Vaziri, Samuel M. Felton
This paper presents a robotic gripper design that can perform customizable grasping tasks at the millimeter scale. The design is based on the origami string, a mechanism with a single degree of freedom that can be mechanically programmed to approximate arbitrary paths in space. By using this concept, we create miniature fingers that bend at multiple joints with a single actuator input. The shape and stiffness of these fingers can be varied to fit different grasping tasks by changing the crease pattern of the string. We show that the experimental behavior of these strings follows their analytical models and that they can perform a variety of tasks including pinching, wrapping, and twisting common objects such as pencils, bottle caps, and blueberries.
本文提出了一种可以在毫米尺度上执行可定制抓取任务的机器人夹具设计。该设计基于折纸弦,这是一种具有单一自由度的机制,可以通过机械编程来近似空间中的任意路径。通过使用这个概念,我们创造了微型手指,可以在多个关节上弯曲,只需一个驱动器输入。这些手指的形状和刚度可以通过改变琴弦的折痕模式来适应不同的抓取任务。我们展示了这些弦的实验行为遵循它们的分析模型,并且它们可以执行各种任务,包括捏,包装和扭曲普通物体,如铅笔,瓶盖和蓝莓。
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引用次数: 6
Error estimation and correction in a spiking neural network for map formation in neuromorphic hardware 神经形态硬件中地图形成的尖峰神经网络误差估计与校正
Pub Date : 2020-05-01 DOI: 10.1109/ICRA40945.2020.9197498
Raphaela Kreiser, Gabriel Waibel, Nuria Armengol, Alpha Renner, Yulia Sandamirskaya
Neuromorphic hardware offers computing platforms for the efficient implementation of spiking neural networks (SNNs) that can be used for robot control. Here, we present such an SNN on a neuromorphic chip that solves a number of tasks related to simultaneous localization and mapping (SLAM): forming a map of an unknown environment and, at the same time, estimating the robot's pose. In particular, we present an SNN mechanism to detect and estimate errors when the robot revisits a known landmark and updates both the map and the path integration speed to reduce the error. The whole system is fully realized in a neuromorphic device, showing the feasibility of a purely SNN-based SLAM, which could be efficiently implemented in a small form-factor neuromorphic chip.
神经形态硬件为峰值神经网络(snn)的有效实现提供了计算平台,可用于机器人控制。在这里,我们在神经形态芯片上提出了这样一个SNN,它解决了许多与同时定位和映射(SLAM)相关的任务:形成未知环境的地图,同时估计机器人的姿势。特别是,我们提出了一种SNN机制来检测和估计机器人重新访问已知地标时的误差,并更新地图和路径集成速度以减少误差。整个系统在神经形态器件中完全实现,表明了纯基于snn的SLAM的可行性,可以在小尺寸神经形态芯片中高效实现。
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引用次数: 13
Dynamic Coupling as an Indicator of Gait Robustness for Underactuated Biped Robots 欠驱动双足机器人步态鲁棒性的动态耦合指标
Pub Date : 2020-05-01 DOI: 10.1109/ICRA40945.2020.9197203
Martin Fevre, J. Schmiedeler
This paper employs velocity decomposition of underactuated mechanical systems to determine the degree of dynamic coupling in the gaits of a two-link biped model. The degree of coupling between controlled and uncontrolled directions quantifies the control authority the system has over its unactuated degree of freedom. This paper shows that the amount of coupling is directly correlated to gait robustness, as seen through the size of the gait’s region of attraction. The analytical measure of coupling is applied in the context of trajectory optimization to generate two-link gaits that maximize or minimize coupling. Simulation studies show that gaits maximizing coupling exhibit significantly superior robustness, as measured by 1) stochastic performance on uneven terrain, 2) ability to maintain desired walking speed under non-vanishing disturbances, 3) size of the region of attraction, and 4) robustness to model uncertainties.
本文采用欠驱动机械系统的速度分解来确定两连杆双足模型步态的动态耦合程度。受控方向和非受控方向之间的耦合程度量化了系统对其非驱动自由度的控制权限。本文表明,通过步态吸引区域的大小可以看出,耦合的数量与步态的鲁棒性直接相关。将耦合的解析度量应用于轨迹优化中,生成最大或最小耦合的双连杆步态。仿真研究表明,步态最大化耦合具有显著的鲁棒性,包括:1)在不平坦地形上的随机性能,2)在不消失干扰下保持所需步行速度的能力,3)吸引力区域的大小,以及4)对模型不确定性的鲁棒性。
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引用次数: 4
SPRINT: Subgraph Place Recognition for INtelligent Transportation SPRINT:智能交通的子图位置识别
Pub Date : 2020-05-01 DOI: 10.1109/ICRA40945.2020.9196522
Y. Latif, Anh-Dzung Doan, Tat-Jun Chin, I. Reid
Visual place recognition is an important problem in mobile robotics which aims to localize a robot using image information alone. Recent methods have shown promising results for place recognition under varying environmental conditions by exploiting the sequential nature of the image acquision process. We show that by using k nearest neighbours based image retrieval as the backend, and exploiting the structure of the image acquisition process which introduces temporal relations between images in the database, the location of possible matches can be restricted to a subset of all the images seen so far. In effect, the original problem space can thus be restricted to a significantly smaller subspace, reducing the inference time significantly. This is particularly important for scalable place recognition over databases containing millions of images. We present large scale experiments using publicly sourced data that show the computational performance of the proposed method under varying environmental conditions.
视觉位置识别是移动机器人技术中的一个重要问题,其目的是仅利用图像信息对机器人进行定位。最近的方法通过利用图像采集过程的顺序性,在不同的环境条件下显示出有希望的位置识别结果。我们表明,通过使用基于k近邻的图像检索作为后端,并利用图像采集过程的结构,该结构引入了数据库中图像之间的时间关系,可能匹配的位置可以限制为迄今为止所看到的所有图像的一个子集。实际上,原始问题空间因此可以被限制到一个更小的子空间,从而大大减少了推理时间。这对于包含数百万图像的数据库的可扩展位置识别尤其重要。我们展示了使用公开来源数据的大规模实验,这些实验显示了所提出的方法在不同环境条件下的计算性能。
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引用次数: 3
Feedback Linearization for Uncertain Systems via Reinforcement Learning 基于强化学习的不确定系统反馈线性化
Pub Date : 2020-05-01 DOI: 10.1109/ICRA40945.2020.9197158
T. Westenbroek, David Fridovich-Keil, Eric V. Mazumdar, Shreyas Arora, Valmik Prabhu, S. Sastry, C. Tomlin
We present a novel approach to control design for nonlinear systems which leverages model-free policy optimization techniques to learn a linearizing controller for a physical plant with unknown dynamics. Feedback linearization is a technique from nonlinear control which renders the input-output dynamics of a nonlinear plant linear under application of an appropriate feedback controller. Once a linearizing controller has been constructed, desired output trajectories for the nonlinear plant can be tracked using a variety of linear control techniques. However, the calculation of a linearizing controller requires a precise dynamics model for the system. As a result, model-based approaches for learning exact linearizing controllers generally require a simple, highly structured model of the system with easily identifiable parameters. In contrast, the model-free approach presented in this paper is able to approximate the linearizing controller for the plant using general function approximation architectures. Specifically, we formulate a continuous-time optimization problem over the parameters of a learned linearizing controller whose optima are the set of parameters which best linearize the plant. We derive conditions under which the learning problem is (strongly) convex and provide guarantees which ensure the true linearizing controller for the plant is recovered. We then discuss how model-free policy optimization algorithms can be used to solve a discrete-time approximation to the problem using data collected from the real-world plant. The utility of the framework is demonstrated in simulation and on a real-world robotic platform.
我们提出了一种新的非线性系统控制设计方法,该方法利用无模型策略优化技术来学习具有未知动态的物理对象的线性化控制器。反馈线性化是非线性控制中的一种技术,它在适当的反馈控制器的作用下,使非线性对象的输入输出动态变为线性。一旦构造了线性化控制器,就可以使用各种线性控制技术跟踪非线性对象的期望输出轨迹。然而,线性化控制器的计算需要精确的系统动力学模型。因此,用于学习精确线性化控制器的基于模型的方法通常需要具有易于识别参数的简单,高度结构化的系统模型。相比之下,本文提出的无模型方法能够使用一般函数近似体系结构近似对象的线性化控制器。具体地说,我们在一个学习的线性化控制器的参数上建立了一个连续时间优化问题,该控制器的最优值是最优线性化对象的参数集。我们导出了学习问题是(强)凸的条件,并提供了保证恢复对象的真线性化控制器的保证。然后,我们讨论了如何使用无模型策略优化算法来使用从现实世界工厂收集的数据来解决问题的离散时间近似。该框架的实用性在仿真和现实世界的机器人平台上得到了验证。
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引用次数: 17
Kinematic Modeling and Compliance Modulation of Redundant Manipulators Under Bracing Constraints 支撑约束下冗余机械手的运动学建模与柔度调制
Pub Date : 2020-05-01 DOI: 10.1109/ICRA40945.2020.9197387
Garrison L. H. Johnston, A. Orekhov, N. Simaan
Collaborative robots should ideally use low torque actuators for passive safety reasons. However, some applications require these collaborative robots to reach deep into confined spaces while assisting a human operator in physically demanding tasks. In this paper, we consider the use of in-situ collaborative robots (ISCRs) that balance the conflicting demands of passive safety dictating low torque actuation and the need to reach into deep confined spaces. We consider the judicious use of bracing as a possible solution to these conflicting demands and present a modeling framework that takes into account the constrained kinematics and the effect of bracing on the endeffector compliance. We then define a redundancy resolution framework that minimizes the directional compliance of the end-effector while maximizing end-effector dexterity. Kinematic simulation results show that the redundancy resolution strategy successfully decreases compliance and improves kinematic conditioning while satisfying the constraints imposed by the bracing task. Applications of this modeling framework can support future research on the choice of bracing locations and support the formation of an admittance control framework for collaborative control of ISCRs under bracing constraints. Such robots can benefit workers in the future by reducing the physiological burdens that contribute to musculoskeletal injury.
出于被动安全考虑,协作机器人应该理想地使用低扭矩执行器。然而,一些应用需要这些协作机器人深入到密闭空间,同时协助人类操作员完成体力要求高的任务。在本文中,我们考虑使用原位协作机器人(ISCRs)来平衡被动安全的冲突需求,即低扭矩驱动和深入受限空间的需求。我们考虑明智地使用支撑作为这些冲突要求的可能解决方案,并提出了一个考虑约束运动学和支撑对效应器顺应性影响的建模框架。然后,我们定义了一个冗余分辨率框架,最大限度地减少了末端执行器的方向顺应性,同时最大限度地提高了末端执行器的灵活性。运动学仿真结果表明,该冗余解决策略在满足支撑任务约束条件的同时,成功地降低了柔度,改善了运动学条件。该模型框架的应用可以支持未来支撑位置选择的研究,并支持形成支撑约束下iscr协同控制的导纳控制框架。这样的机器人可以减少导致肌肉骨骼损伤的生理负担,从而使未来的工人受益。
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引用次数: 4
SwarmRail: A Novel Overhead Robot System for Indoor Transport and Mobile Manipulation 用于室内运输和移动操作的新型架空机器人系统
Pub Date : 2020-05-01 DOI: 10.1109/ICRA40945.2020.9196972
M. Görner, Fabian Benedikt, Ferdinand Grimmel, T. Hulin
SwarmRail represents a novel solution to overhead manipulation from a mobile unit that drives in an aboveground rail-structure. The concept is based on the combination of omnidirectional mobile platform and L-shaped rail profiles that form a through-going central gap. This gap makes possible mounting a robotic manipulator arm overhead at the underside of the mobile platform. Compared to existing solutions, SwarmRail enables continuous overhead manipulation while traversing rail crossings. It also can be operated in a robot swarm, as it allows for concurrent operation of a group of mobile SwarmRail units inside a single rail network. Experiments on a first functional demonstrator confirm the functional capability of the concept. Potential fields of applications reach from industry over logistics to vertical farming.
SwarmRail代表了一种新颖的解决方案,通过在地上轨道结构中驱动的移动单元来进行架空操作。这个概念是基于全方位移动平台和l型轨道轮廓的组合,形成一个贯穿的中央缺口。这个间隙使得在移动平台的底部安装一个机械臂成为可能。与现有的解决方案相比,SwarmRail可以在穿越铁路道口时实现连续的架空操作。它也可以在机器人群中运行,因为它允许在单个轨道网络中同时运行一组移动的SwarmRail单元。在第一个功能演示器上的实验证实了该概念的功能能力。潜在的应用领域从物流工业到垂直农业。
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引用次数: 2
期刊
2020 IEEE International Conference on Robotics and Automation (ICRA)
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