Hierarchical Task-Priority Control for Human-Robot Co-manipulation

The extensive distribution of collaborative robots in indus- trial workplaces allows human operators to decrease the weight and the repetitiveness of their activities. In order to facilitate the role of the human worker during the interaction with these robots, innovative con- trol paradigms, enabling an intuitive human-robot collaborative manipu- lation, are needed. In this work, a dynamic and hierarchical task-priority control framework is proposed, leveraging a physical interaction with a redundant robot manipulator through a force sensor. The foremost objec- tive of this approach is to exploit the non-trivial null-space of the redun- dant robot to increase the performance of the co-manipulation and, con- sequently, its effectiveness. A comparison between the proposed method- ology and a standard admittance control scheme is carried out within an industrial use case study consisting of a human operator interacting with a KUKA LBR iiwa arm

A Control Architecture for Unmanned Aerial Vehicles Operating in Human-Robot Team for Service Robotic Tasks

In this thesis a Control architecture for an Unmanned Aerial Vehicle (UAV) is presented. The aim of the thesis is to address the problem of control a flying robot operating in human robot team at different level of abstraction. For this purpose, three different layers in the design of the architecture were considered, namely, the high level, the middle level and the low level layers. The special case of an UAV operating in service robotics tasks and in particular in Search&Rescue mission in alpine scenario is considered. Different methodologies for each layer are presented with simulated or real-world experimental validation

Race at the Pivot Point: The Future of Race-Based Policies to Remedy De Jure Segregation After Parents Involved in Community Schools

This article examines the perhaps unintended consequences of changing legal doctrine. Most commentary on the U.S. Supreme Court Parents Involved in Community Schools (“PICS”) decision explores PICS’ impact upon voluntary race-based policies to remedy unintentional de facto racial segregation. In contrast, this analysis explores PICS’ impact upon mandatory race-based policies to remedy government-sponsored de jure racial segregation. After PICS, the Fourteenth Amendment’s essence and character can turn on a finding of unitary status, a purely factual and somewhat subjective determination reviewable only for clear error. Under the Equal Protection Clause, a school district found to operate a de jure segregated school system may be forced to use race-based policies to undo the effects of such segregation. The instant, however, that a district judge signs the court order granting that school district unitary status, the Equal Protection Clause then forbids the school district from using the identical race-based policies to address the effects of de facto segregation. PICS thus has injected into the Equal Protection Clause’s schizophrenic identity a never-before-seen wrinkle called a pivot point.The pivot point arises when school systems constitutionally required to use race-based policies to remedy de jure segregation become constitutionally prohibited from using the same race-based policies to address de facto segregation voluntarily. After exploring PICS’ effect on de jure school systems’ legal obligations, we explore the ramifications of a constitutional standard that abruptly transforms legal obligations on the basis of a subjective factual determination. This pivot point may induce bizarre effects in familiar legal processes, with unpredictable consequences. In its zeal to alter Brown v. Board of Education’s legacy, the PICS majority overlooked the structural impact of its decision on de jure systems governed by a very different vision of the Equal Protection Clause. The resulting pivot point is a testament to the dangers of parsing individual rights too finely at the expense of maintaining stability in legal structure and process

Hybrid visual servoing with hierarchical task composition for aerial manipulation

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In this paper a hybrid visual servoing with a hierarchical task-composition control framework is described for aerial manipulation, i.e. for the control of an aerial vehicle endowed with a robot arm. The proposed approach suitably combines into a unique hybrid-control framework the main benefits of both image-based and position-based control schemes. Moreover, the underactuation of the aerial vehicle has been explicitly taken into account in a general formulation, together with a dynamic smooth activation mechanism. Both simulation case studies and experiments are presented to demonstrate the performance of the proposed technique.Peer ReviewedPostprint (author's final draft

Active Disturbance Rejection Control for the Robust Flight of a Passively Tilted Hexarotor

This paper presents a robust control strategy for controlling the flight of a passively (fixed) tilted hexarotor unmanned aerial vehicle (UAV). The proposed controller is based on a robust extended-state observer to estimate and reject internal dynamics and external disturbances at run-time. Both stability and convergence of the observer are proved using Lyapunov-based perturbation theory and an ultimate bound approach. Such a controller is implemented within a highly realistic simulation environment that includes physics motors, devising an almost transparent behaviour with respect to the real UAV. The controller is tested for flying under normal conditions and in the presence of different types of disturbances showing successful results. Furthermore, the proposed control system is compared against another robust control approach, presenting a better performance regarding the attenuation of the error signals

A Shared-Control Teleoperation Architecture for Nonprehensile Object Transportation

This article proposes a shared-control teleoperation architecture for robot manipulators transporting an object on a tray. Differently from many existing studies about remotely operated robots with firm grasping capabilities, we consider the case in which, in principle, the object can break its contact with the robot end-effector. The proposed shared-control approach automatically regulates the remote robot motion commanded by the user and the end-effector orientation to prevent the object from sliding over the tray. Furthermore, the human operator is provided with haptic cues informing about the discrepancy between the commanded and executed robot motion, which assist the operator throughout the task execution. We carried out trajectory tracking experiments employing an autonomous 7-degree-of-freedom (DoF) manipulator and compared the results obtained using the proposed approach with two different control schemes (i.e., constant tray orientation and no motion adjustment). We also carried out a human-subjects study involving 18 participants in which a 3-DoF haptic device was used to teleoperate the robot linear motion and display haptic cues to the operator. In all experiments, the results clearly show that our control approach outperforms the other solutions in terms of sliding prevention, robustness, commands tracking, and user’s preference

Networking for Cloud Robotics: The DewROS Platform and Its Application

With the advances in networking technologies, robots can use the almost unlimited resources of large data centers, overcoming the severe limitations imposed by onboard resources: this is the vision of Cloud Robotics. In this context, we present DewROS, a framework based on the Robot Operating System (ROS) which embodies the three-layer, Dew-Robotics architecture, where computation and storage can be distributed among the robot, the network devices close to it, and the Cloud. After presenting the design and implementation of DewROS, we show its application in a real use-case called SHERPA, which foresees a mixed ground and aerial robotic platform for search and rescue in an alpine environment. We used DewROS to analyze the video acquired by the drones in the Cloud and quickly spot signs of human beings in danger. We perform a wide experimental evaluation using different network technologies and Cloud services from Google and Amazon. We evaluated the impact of several variables on the performance of the system. Our results show that, for example, the video length has a minimal impact on the response time with respect to the video size. In addition, we show that the response time depends on the Round Trip Time (RTT) of the network connection when the video is already loaded into the Cloud provider side. Finally, we present a model of the annotation time that considers the RTT of the connection used to reach the Cloud, discussing results and insights into how to improve current Cloud Robotics applications

Safe local aerial manipulation for the installation of devices on power lines: Aerial-core first year results and designs

Article number 6220The power grid is an essential infrastructure in any country, comprising thousands of kilometers of power lines that require periodic inspection and maintenance, carried out nowadays by human operators in risky conditions. To increase safety and reduce time and cost with respect to conventional solutions involving manned helicopters and heavy vehicles, the AERIAL-CORE project proposes the development of aerial robots capable of performing aerial manipulation operations to assist human operators in power lines inspection and maintenance, allowing the installation of devices, such as bird flight diverters or electrical spacers, and the fast delivery and retrieval of tools. This manuscript describes the goals and functionalities to be developed for safe local aerial manipulation, presenting the preliminary designs and experimental results obtained in the first year of the project.European Union (UE). H2020 871479Ministerio de Ciencia, Innovación y Universidades de España FPI 201

Nonprehensile Manipulation of Deformable Objects: Achievements and Perspectives from the RobDyMan Project

International audienceThe goal of this work is to disseminate the results achieved so far within the RODYMAN project related to planning and control strategies for robotic nonprehensile manipulation. The project aims at advancing the state of the art of nonprehensile dynamic manipulation of rigid and deformable objects to future enhance the possibility of employing robots in anthropic environments. The final demonstrator of the RODYMAN project will be an autonomous pizza maker. This article is a milestone to highlight the lessons learned so far and pave the way towards future research directions and critical discussions