Robotics

16 pages, 9212 KiB

Open AccessTechnical Note

Engineering Interoperable, Plug-and-Play, Distributed, Robotic Control Systems for Futureproof Fusion Power Plants

by Ipek Caliskanelli, Matthew Goodliffe, Craig Whiffin, Michail Xymitoulias, Edward Whittaker, Swapnil Verma and Robert Skilton

Robotics 2021, 10(3), 108; https://doi.org/10.3390/robotics10030108 - 16 Sep 2021

Cited by 3 | Viewed by 3432

Abstract

Maintenance and inspection systems for future fusion power plants (e.g., STEP and DEMO) are expected to require the integration of hundreds of systems from multiple suppliers, with lifetime expectancies of several decades, where requirements evolve over time and obsolescence management is required. There [...] Read more.

Maintenance and inspection systems for future fusion power plants (e.g., STEP and DEMO) are expected to require the integration of hundreds of systems from multiple suppliers, with lifetime expectancies of several decades, where requirements evolve over time and obsolescence management is required. There are significant challenges associated with the integration, deployment, and maintenance of very large-scale robotic systems incorporating devices from multiple suppliers, where each may utilise bespoke, non-standardised control systems and interfaces. Additionally, the unstructured, experimental, or unknown operational conditions frequently result in new or changing system requirements, meaning extension and adaptation are necessary. Whilst existing control frameworks (e.g., ROS, OPC-UA) allow for the robust integration of complex robotic systems, they are not compatible with highly efficient maintenance and extension in the face of changing requirements and obsolescence issues over decades-long periods. We present the CorteX software framework as well as results showing its effectiveness in addressing the above issues, whilst being demonstrated through hardware that is representative of real-world fusion applications. Full article

(This article belongs to the Special Issue Advances in Robots for Hazardous Environments in the UK)

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18 pages, 6069 KiB

Open AccessArticle

Nut Unfastening by Robotic Surface Exploration

by Alireza Rastegarpanah, Rohit Ner, Rustam Stolkin and Naresh Marturi

Robotics 2021, 10(3), 107; https://doi.org/10.3390/robotics10030107 - 14 Sep 2021

Cited by 11 | Viewed by 4750

Abstract

In this paper, we present a novel concept and primary investigations regarding automated unfastening of hexagonal nuts by means of surface exploration with a compliant robot. In contrast to the conventional industrial approaches that rely on custom-designed motorised tools and mechanical tool changers, [...] Read more.

In this paper, we present a novel concept and primary investigations regarding automated unfastening of hexagonal nuts by means of surface exploration with a compliant robot. In contrast to the conventional industrial approaches that rely on custom-designed motorised tools and mechanical tool changers, we propose to use robot fingers to position, grasp and unfasten unknown random-sized hexagonal nuts, which are arbitrarily positioned in the robot’s task space. Inspired by how visually impaired people handle unknown objects, in this work, we use information observed from surface exploration to devise the unfastening strategy. It combines torque monitoring with active compliance for the robot fingers to smoothly explore the object’s surface. We implement a shape estimation technique combining scaled iterative closest point and hypotrochoid approximation to estimate the location as well as contour profile of the hexagonal nut so as to accurately position the gripper fingers. We demonstrate this work in the context of dismantling an electrically driven vehicle battery pack. The experiments are conducted using a seven degrees of freedom (DoF)–compliant robot fitted with a two-finger gripper to unfasten four different sized randomly positioned hexagonal nuts. The obtained results suggest an overall exploration and unfastening success rate of 95% over an average of ten trials for each nut. Full article

(This article belongs to the Special Issue Control of Robots Physically Interacting with Humans and Environment)

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23 pages, 1757 KiB

Open AccessReview

Socially Assistive Robots Helping Older Adults through the Pandemic and Life after COVID-19

by Cristina Getson and Goldie Nejat

Robotics 2021, 10(3), 106; https://doi.org/10.3390/robotics10030106 - 13 Sep 2021

Cited by 42 | Viewed by 12838

Abstract

The COVID-19 pandemic has critically impacted the health and safety of the population of the world, especially the health and well-being of older adults. Socially assistive robots (SARs) have been used to help to mitigate the effects of the pandemic including loneliness and [...] Read more.

The COVID-19 pandemic has critically impacted the health and safety of the population of the world, especially the health and well-being of older adults. Socially assistive robots (SARs) have been used to help to mitigate the effects of the pandemic including loneliness and isolation, and to alleviate the workload of both formal and informal caregivers. This paper presents the first extensive survey and discussion on just how socially assistive robots have specifically helped this population, as well as the overall impact on health and the acceptance of such robots during the pandemic. The goal of this review is to answer research questions with respect to which SARs were used during the pandemic and what specific tasks they were used for, and what the enablers and barriers were to the implementation of SARs during the pandemic. We will also discuss lessons learned from their use to inform future SAR design and applications, and increase their usefulness and adoption in a post-pandemic world. More research is still needed to investigate and appreciate the user experience of older adults with SARs during the pandemic, and we aim to provide a roadmap for researchers and stakeholders. Full article

(This article belongs to the Special Issue Service Robotics against COVID-2019 Pandemic)

28 pages, 1878 KiB

Open AccessReview

Reinforcement Learning for Pick and Place Operations in Robotics: A Survey

by Andrew Lobbezoo, Yanjun Qian and Hyock-Ju Kwon

Robotics 2021, 10(3), 105; https://doi.org/10.3390/robotics10030105 - 13 Sep 2021

Cited by 30 | Viewed by 15920

Abstract

The field of robotics has been rapidly developing in recent years, and the work related to training robotic agents with reinforcement learning has been a major focus of research. This survey reviews the application of reinforcement learning for pick-and-place operations, a task that [...] Read more.

The field of robotics has been rapidly developing in recent years, and the work related to training robotic agents with reinforcement learning has been a major focus of research. This survey reviews the application of reinforcement learning for pick-and-place operations, a task that a logistics robot can be trained to complete without support from a robotics engineer. To introduce this topic, we first review the fundamentals of reinforcement learning and various methods of policy optimization, such as value iteration and policy search. Next, factors which have an impact on the pick-and-place task, such as reward shaping, imitation learning, pose estimation, and simulation environment are examined. Following the review of the fundamentals and key factors for reinforcement learning, we present an extensive review of all methods implemented by researchers in the field to date. The strengths and weaknesses of each method from literature are discussed, and details about the contribution of each manuscript to the field are reviewed. The concluding critical discussion of the available literature, and the summary of open problems indicates that experiment validation, model generalization, and grasp pose selection are topics that require additional research. Full article

(This article belongs to the Special Issue 10th Anniversary of Robotics—Feature Papers in Intelligent Robots and Mechatronics)

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16 pages, 46353 KiB

Open AccessArticle

Cylindabot: Transformable Wheg Robot Traversing Stepped and Sloped Environments

by Robert Woolley, Jon Timmis and Andy M. Tyrrell

Robotics 2021, 10(3), 104; https://doi.org/10.3390/robotics10030104 - 30 Aug 2021

Cited by 4 | Viewed by 4584

Abstract

The ability of an autonomous robot to adapt to different terrain affords the flexibility to move successfully in a range of environments. This paper proposes the Cylindabot, a transformable Wheg robot that can move with two large wheels, each of which can rotate [...] Read more.

The ability of an autonomous robot to adapt to different terrain affords the flexibility to move successfully in a range of environments. This paper proposes the Cylindabot, a transformable Wheg robot that can move with two large wheels, each of which can rotate out, producing three legs. This ability to change its mode of locomotion allows for specialised performance. The Cylindabot has been tested in simulation and on a physical robot on steps and slopes as an indication of its efficacy in different environments. These experiments show that such robots are capable of climbing up to a 32 degree slope and a step 1.43 times their initial height. Theoretical limits are devised that match the results, and a comparison with existing Wheg platforms is made. Full article

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11 pages, 1491 KiB

Open AccessArticle

A Case Study on Improving the Software Dependability of a ROS Path Planner for Steep Slope Vineyards

by Luís Carlos Santos, André Santos, Filipe Neves Santos and António Valente

Robotics 2021, 10(3), 103; https://doi.org/10.3390/robotics10030103 - 26 Aug 2021

Cited by 3 | Viewed by 3297

Abstract

Software for robotic systems is becoming progressively more complex despite the existence of established software ecosystems like ROS, as the problems we delegate to robots become more and more challenging. Ensuring that the software works as intended is a crucial (but not trivial) [...] Read more.

Software for robotic systems is becoming progressively more complex despite the existence of established software ecosystems like ROS, as the problems we delegate to robots become more and more challenging. Ensuring that the software works as intended is a crucial (but not trivial) task, although proper quality assurance processes are rarely seen in the open-source robotics community. This paper explains how we analyzed and improved a specialized path planner for steep-slope vineyards regarding its software dependability. The analysis revealed previously unknown bugs in the system, with a relatively low property specification effort. We argue that the benefits of similar quality assurance processes far outweigh the costs and should be more widespread in the robotics domain. Full article

(This article belongs to the Special Issue Advances in Agriculture and Forest Robotics)

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13 pages, 5011 KiB

Open AccessArticle

Paquitop.arm, a Mobile Manipulator for Assessing Emerging Challenges in the COVID-19 Pandemic Scenario

by Giovanni Colucci, Luigi Tagliavini, Luca Carbonari, Paride Cavallone, Andrea Botta and Giuseppe Quaglia

Robotics 2021, 10(3), 102; https://doi.org/10.3390/robotics10030102 - 14 Aug 2021

Cited by 8 | Viewed by 4591

Abstract

The use of automation and robotics technologies for caregiving and assistance has become a very interesting research topic in the field of robotics. The spread of COVID-19 has highlighted the importance of social distancing in hospitals and health centers, and collaborative robotics can [...] Read more.

The use of automation and robotics technologies for caregiving and assistance has become a very interesting research topic in the field of robotics. The spread of COVID-19 has highlighted the importance of social distancing in hospitals and health centers, and collaborative robotics can bring substantial improvements in terms of sparing health workers basic operations. Thus, researchers from Politecnico di Torino are working on Paquitop.arm, a mobile robot for assistive tasks. The purpose of this paper is to present a system composed of an omnidirectional mobile platform, a 6 DOF robot arm, and a depth camera. Task-oriented considerations are made to estimate a set of mounting parameters that represents a trade-off between the exploitation of the robot arm workspace and the compactness of the entire system. To this end, dexterity and force transmission indexes are introduced to study both the kinematic and the static behavior of the manipulator as a function of the mounting parameters. Finally, to avoid singularities during the execution of the task, the platform approach to the task workspaces is studied. Full article

(This article belongs to the Special Issue Service Robotics against COVID-2019 Pandemic)

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15 pages, 3994 KiB

Open AccessArticle

Multidirectional Overground Robotic Training Leads to Improvements in Balance in Older Adults

by Lara A. Thompson, Mehdi Badache, Joao Augusto Renno Brusamolin, Marzieh Savadkoohi, Jelani Guise, Gabriel Velluto de Paiva, Pius Suh, Pablo Sanchez Guerrero and Devdas Shetty

Robotics 2021, 10(3), 101; https://doi.org/10.3390/robotics10030101 - 6 Aug 2021

Cited by 4 | Viewed by 4262

Abstract

For the rapidly growing aging demographic worldwide, robotic training methods could be impactful towards improving balance critical for everyday life. Here, we investigated the hypothesis that non-bodyweight supportive (nBWS) overground robotic balance training would lead to improvements in balance performance and balance confidence [...] Read more.

For the rapidly growing aging demographic worldwide, robotic training methods could be impactful towards improving balance critical for everyday life. Here, we investigated the hypothesis that non-bodyweight supportive (nBWS) overground robotic balance training would lead to improvements in balance performance and balance confidence in older adults. Sixteen healthy older participants (69.7 ± 6.7 years old) were trained while donning a harness from a distinctive NaviGAITor robotic system. A control group of 11 healthy participants (68.7 ± 5.0 years old) underwent the same training but without the robotic system. Training included 6 weeks of standing and walking tasks while modifying: (1) sensory information (i.e., with and without vision (eyes-open/closed), with more and fewer support surface cues (hard or foam surfaces)) and (2) base-of-support (wide, tandem and single-leg standing exercises). Prior to and post-training, balance ability and balance confidence were assessed via the balance error scoring system (BESS) and the Activities specific Balance Confidence (ABC) scale, respectively. Encouragingly, results showed that balance ability improved (i.e., BESS errors significantly decreased), particularly in the nBWS group, across nearly all test conditions. This result serves as an indication that robotic training has an impact on improving balance for healthy aging individuals. Full article

(This article belongs to the Special Issue Robots for Health and Elderly Care)

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22 pages, 12218 KiB

Open AccessReview

Trends in the Control of Hexapod Robots: A Survey

by Joana Coelho, Fernando Ribeiro, Bruno Dias, Gil Lopes and Paulo Flores

Robotics 2021, 10(3), 100; https://doi.org/10.3390/robotics10030100 - 4 Aug 2021

Cited by 29 | Viewed by 8182

Abstract

The static stability of hexapods motivates their design for tasks in which stable locomotion is required, such as navigation across complex environments. This task is of high interest due to the possibility of replacing human beings in exploration, surveillance and rescue missions. For [...] Read more.

The static stability of hexapods motivates their design for tasks in which stable locomotion is required, such as navigation across complex environments. This task is of high interest due to the possibility of replacing human beings in exploration, surveillance and rescue missions. For this application, the control system must adapt the actuation of the limbs according to their surroundings to ensure that the hexapod does not tumble during locomotion. The most traditional approach considers their limbs as robotic manipulators and relies on mechanical models to actuate them. However, the increasing interest in model-free models for the control of these systems has led to the design of novel solutions. Through a systematic literature review, this paper intends to overview the trends in this field of research and determine in which stage the design of autonomous and adaptable controllers for hexapods is. Full article

(This article belongs to the Special Issue Recent Trends and Advances in Mechanism Design and Robotics)

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14 pages, 2137 KiB

Open AccessArticle

Kinematic Synthesis and Analysis of the RoboMech Class Parallel Manipulator with Two Grippers

by Zhumadil Baigunchekov, Med Amine Laribi, Azamat Mustafa and Abzal Kassinov

Robotics 2021, 10(3), 99; https://doi.org/10.3390/robotics10030099 - 3 Aug 2021

Cited by 5 | Viewed by 3553

Abstract

In this paper, methods of kinematic synthesis and analysis of the RoboMech class parallel manipulator (PM) with two grippers (end effectors) are presented. This PM is formed by connecting two output objects (grippers) with a base using two passive and one negative closing [...] Read more.

In this paper, methods of kinematic synthesis and analysis of the RoboMech class parallel manipulator (PM) with two grippers (end effectors) are presented. This PM is formed by connecting two output objects (grippers) with a base using two passive and one negative closing kinematic chains (CKCs). A PM with two end effectors can be used for reloading operations of stamped products between two adjacent main technologies in a cold stamping line. Passive CKCs represent two serial manipulators with two degrees of freedom, and negative CKC is a three-joined link with three negative degrees of freedom. A negative CKC imposes three geometric constraints on the movements of the two output objects. Geometric parameters of the negative CKC are determined on the basis of the problems of the Chebyshev and least-square approximations. Problems of positions and analogues of velocities and accelerations of the PM with two end effectors have been solved. Full article

(This article belongs to the Special Issue Kinematics and Robot Design IV, KaRD2021)

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27 pages, 7672 KiB

Open AccessArticle

Self-Disclosure to a Robot: Only for Those Who Suffer the Most

by Yunfei (Euphie) Duan, Myung (Ji) Yoon, Zhixuan (Edison) Liang and Johan Ferdinand Hoorn

Robotics 2021, 10(3), 98; https://doi.org/10.3390/robotics10030098 - 29 Jul 2021

Cited by 12 | Viewed by 6098

Abstract

Social robots may become an innovative means to improve the well-being of individuals. Earlier research has shown that people easily self-disclose to a social robot, even in cases where it was unintended by the designers. We report on an experiment considering self-disclosing in [...] Read more.

Social robots may become an innovative means to improve the well-being of individuals. Earlier research has shown that people easily self-disclose to a social robot, even in cases where it was unintended by the designers. We report on an experiment considering self-disclosing in a diary journal or to a social robot after negative mood induction. An off-the-shelf robot was complemented with our in-house developed AI chatbot, which could talk about ‘hot topics’ after training it with thousands of entries on a complaint website. We found that people who felt strongly negative after being exposed to shocking video footage benefited the most from talking to our robot, rather than writing down their feelings. For people less affected by the treatment, a confidential robot chat or writing a journal page did not differ significantly. We discuss emotion theory in relation to robotics and possibilities for an application in design (the emoji-enriched ‘talking stress ball’). We also underline the importance of otherwise disregarded outliers in a data set of therapeutic nature. Full article

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Graphical abstract

34 pages, 13516 KiB

Open AccessArticle

Towards the Determination of Safe Operating Envelopes for Autonomous UAS in Offshore Inspection Missions

by Vincent Page, Christopher Dadswell, Matt Webster, Mike Jump and Michael Fisher

Robotics 2021, 10(3), 97; https://doi.org/10.3390/robotics10030097 - 28 Jul 2021

Cited by 3 | Viewed by 4323

Abstract

A drive to reduce costs, carbon emissions, and the number of required personnel in the offshore energy industry has led to proposals for the increased use of autonomous/robotic systems for many maintenance tasks. There are questions over how such missions can be shown [...] Read more.

A drive to reduce costs, carbon emissions, and the number of required personnel in the offshore energy industry has led to proposals for the increased use of autonomous/robotic systems for many maintenance tasks. There are questions over how such missions can be shown to be safe. A corollary exists in the manned aviation world for helicopter–ship operations where a test pilot attempts to operate from a ship under a range of wind conditions and provides subjective feedback on the level of difficulty encountered. This defines the ship–helicopter operating limit envelope (SHOL). Due to the cost of creating a SHOL there has been considerable research activity to demonstrate that much of this process can be performed virtually. Unmanned vehicles, however, have no test pilot to provide feedback. This paper therefore explores the possibility of adapting manned simulation techniques to the unmanned world to demonstrate that a mission is safe. Through flight modelling and simulation techniques it is shown that operating envelopes can be created for an oil rig inspection task and that, by using variable performance specifications, these can be tailored to suit the level of acceptable risk. The operating envelopes produced provide condensed and intelligible information regarding the environmental conditions under which the UAS can perform the task. Full article

(This article belongs to the Special Issue Advances in Robots for Hazardous Environments in the UK)

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18 pages, 9847 KiB

Open AccessArticle

The WL_PCR: A Planning for Ground-to-Pole Transition of Wheeled-Legged Pole-Climbing Robots

by Yankai Wang, Qiaoling Du, Tianhe Zhang and Chengze Xue

Robotics 2021, 10(3), 96; https://doi.org/10.3390/robotics10030096 - 27 Jul 2021

Cited by 2 | Viewed by 4455

Abstract

Hybrid mobile robots with two motion modes of a wheeled vehicle and truss structure with the ability to climb poles have significant flexibility. The motion planning of this kind of robot on a pole has been widely studied, but few studies have focused [...] Read more.

Hybrid mobile robots with two motion modes of a wheeled vehicle and truss structure with the ability to climb poles have significant flexibility. The motion planning of this kind of robot on a pole has been widely studied, but few studies have focused on the transition of the robot from the ground to the pole. In this study, a locomotion strategy of wheeled-legged pole-climbing robots (the WL_PCR) is proposed to solve the problem of ground-to-pole transition. By analyzing the force of static and dynamic process in the ground-to-pole transition, the condition of torque provided by the gripper and moving joint is proposed. The mathematical expression of Centre of Mass (CoM) of the wheeled-legged pole-climbing robots is utilized, and the conditions for the robot to smoothly transition from the ground to the vertical pole are proposed. Finally, the feasibility of this method is proved by the simulation and experimentation of a locomotion strategy on wheeled-legged pole-climbing robots. Full article

(This article belongs to the Topic Motion Planning and Control for Robotics)

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12 pages, 3061 KiB

Open AccessCommunication

An Adaptive Assistance Controller to Optimize the Exoskeleton Contribution in Rehabilitation

by Rezvan Nasiri, Mohammad Shushtari and Arash Arami

Robotics 2021, 10(3), 95; https://doi.org/10.3390/robotics10030095 - 24 Jul 2021

Cited by 15 | Viewed by 4910

Abstract

In this paper, we present a novel adaptation rule to optimize the exoskeleton assistance in rehabilitation tasks. The proposed method adapts the exoskeleton contribution to user impairment severity without any prior knowledge about the user motor capacity. The proposed controller is a combination [...] Read more.

In this paper, we present a novel adaptation rule to optimize the exoskeleton assistance in rehabilitation tasks. The proposed method adapts the exoskeleton contribution to user impairment severity without any prior knowledge about the user motor capacity. The proposed controller is a combination of an adaptive feedforward controller and a low gain adaptive PD controller. The PD controller guarantees the stability of the human-exoskeleton system during feedforward torque adaptation by utilizing only the human-exoskeleton joint positions as the sensory feedback for assistive torque optimization. In addition to providing a convergence proof, in order to study the performance of our method we applied it to a simplified 2-DOF model of human-arm and a generic 9-DOF model of lower limb to perform walking. In each simulated task, we implemented the impaired human torque to be insufficient for the task completion. Moreover, the scenarios that violate our convergence proof assumptions are considered. The simulation results show a converging behavior for the proposed controller; the maximum convergence time of 20 s is observed. In addition, a stable control performance that optimally supplements the remaining user motor contribution is observed; the joint angle tracking error in steady condition and its improvement compared to the start of adaptation are as follows: shoulder

0.96 \pm 2.53 °

(

76 %

); elbow

- 0.35 \pm 0.81 °

(

33 %

); hip

0.10 \pm 0.86 °

(

38 %

); knee

- 0.19 \pm 0.67 °

(

25 %

); and ankle

- 0.05 \pm 0.20 °

(

60 %

). The presented simulation results verify the robustness of proposed adaptive method in cases that differ from our mathematical assumptions and indicate its potentials to be used in practice. Full article

(This article belongs to the Section Medical Robotics and Service Robotics)

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22 pages, 65733 KiB

Open AccessArticle

A Study on the Feasibility of Robotic Harvesting for Chile Pepper

by Muhammad Umar Masood and Mahdi Haghshenas-Jaryani

Robotics 2021, 10(3), 94; https://doi.org/10.3390/robotics10030094 - 22 Jul 2021

Cited by 8 | Viewed by 7221

Abstract

This paper presents a study on the robotic harvesting of New Mexico type chile pepper, in a laboratory setting, using a five degrees of freedom (DoF) serial manipulator. The end-effector of the manipulator, a scissor-type cutting mechanism, was devised and experimentally tested in [...] Read more.

This paper presents a study on the robotic harvesting of New Mexico type chile pepper, in a laboratory setting, using a five degrees of freedom (DoF) serial manipulator. The end-effector of the manipulator, a scissor-type cutting mechanism, was devised and experimentally tested in a lab setup which cuts the chile stem to detach the fruit. Through a MATLAB™-based program, the location of the chile pepper is estimated in the robot’s reference frame, using Intel RealSense Depth Camera. The accuracy of the 3D location estimation system matches the maximum accuracy claimed by the manufacturer of the hardware, with a maximum error to be in Y-axis, which is 5.7 mm. The forward and inverse kinematics are developed, and the reachable and dexterous workspaces of the robot are studied. An application-based path planning algorithm is developed to minimize the travel for a specified harvesting task. The robotic harvesting system was able to cut the chile pepper from the plant based on 3D location estimated by MATLAB™ program. On the basis of harvesting operation, on 77 chile peppers, the following harvesting indicators were achieved: localization success rate of 37.7%, detachment success rate of 65.5%, harvest success rate of 24.7%, damage rate of 6.9%, and cycle time of 7 s. Full article

(This article belongs to the Special Issue Advances in Agriculture and Forest Robotics)

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11 pages, 1185 KiB

Open AccessCommunication

Variational AutoEncoder to Identify Anomalous Data in Robots

by Luigi Pangione, Guy Burroughes and Robert Skilton

Robotics 2021, 10(3), 93; https://doi.org/10.3390/robotics10030093 - 21 Jul 2021

Cited by 2 | Viewed by 3632

Abstract

For robotic systems involved in challenging environments, it is crucial to be able to identify faults as early as possible. In challenging environments, it is not always possible to explore all of the fault space, thus anomalous data can act as a broader [...] Read more.

For robotic systems involved in challenging environments, it is crucial to be able to identify faults as early as possible. In challenging environments, it is not always possible to explore all of the fault space, thus anomalous data can act as a broader surrogate, where an anomaly may represent a fault or a predecessor to a fault. This paper proposes a method for identifying anomalous data from a robot, whilst using minimal nominal data for training. A Monte Carlo ensemble sampled Variational AutoEncoder was utilised to determine nominal and anomalous data through reconstructing live data. This was tested on simulated anomalies of real data, demonstrating that the technique is capable of reliably identifying an anomaly without any previous knowledge of the system. With the proposed system, we obtained an F1-score of

0.85

through testing. Full article

(This article belongs to the Special Issue Advances in Robots for Hazardous Environments in the UK)

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10 pages, 594 KiB

Open AccessPerspective

Contextualizing Human—Automated Vehicle Interactions: A Socio-Ecological Framework

by Lionel Peter Robert

Robotics 2021, 10(3), 92; https://doi.org/10.3390/robotics10030092 - 20 Jul 2021

Cited by 1 | Viewed by 4055

Abstract

Automated vehicles (AVs) have given rise to a new field of study: human—automated vehicle interaction (H–AVI). Unfortunately, the H–AVI field has largely ignored the importance of context. To address this, this paper describes a socio-ecological view of H–AVI. Drawing on this view, the [...] Read more.

Automated vehicles (AVs) have given rise to a new field of study: human—automated vehicle interaction (H–AVI). Unfortunately, the H–AVI field has largely ignored the importance of context. To address this, this paper describes a socio-ecological view of H–AVI. Drawing on this view, the author briefly discusses and identifies unexplored areas. In doing so, the author draws attention to: (i) transportation infrastructure, (ii) national and regional differences, (iii) special and vulnerable populations and (iv) the impacts of multiple H–AVI types. This paper describes the challenges and opportunities in each of these areas. Full article

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29 pages, 17136 KiB

Open AccessArticle

The Wearable Robotic Forearm: Design and Predictive Control of a Collaborative Supernumerary Robot

by Vighnesh Vatsal and Guy Hoffman

Robotics 2021, 10(3), 91; https://doi.org/10.3390/robotics10030091 - 16 Jul 2021

Cited by 9 | Viewed by 6370

Abstract

This article presents the design process of a supernumerary wearable robotic forearm (WRF), along with methods for stabilizing the robot’s end-effector using human motion prediction. The device acts as a lightweight “third arm” for the user, extending their reach during handovers and manipulation [...] Read more.

This article presents the design process of a supernumerary wearable robotic forearm (WRF), along with methods for stabilizing the robot’s end-effector using human motion prediction. The device acts as a lightweight “third arm” for the user, extending their reach during handovers and manipulation in close-range collaborative activities. It was developed iteratively, following a user-centered design process that included an online survey, contextual inquiry, and an in-person usability study. Simulations show that the WRF significantly enhances a wearer’s reachable workspace volume, while remaining within biomechanical ergonomic load limits during typical usage scenarios. While operating the device in such scenarios, the user introduces disturbances in its pose due to their body movements. We present two methods to overcome these disturbances: autoregressive (AR) time series and a recurrent neural network (RNN). These models were used for forecasting the wearer’s body movements to compensate for disturbances, with prediction horizons determined through linear system identification. The models were trained offline on a subset of the KIT Human Motion Database, and tested in five usage scenarios to keep the 3D pose of the WRF’s end-effector static. The addition of the predictive models reduced the end-effector position errors by up to 26% compared to direct feedback control. Full article

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23 pages, 1459 KiB

Open AccessArticle

Nonlinear Model Predictive Horizon for Optimal Trajectory Generation

by Younes Al Younes and Martin Barczyk

Robotics 2021, 10(3), 90; https://doi.org/10.3390/robotics10030090 - 14 Jul 2021

Cited by 10 | Viewed by 5160

Abstract

This paper presents a trajectory generation method for a nonlinear system under closed-loop control (here a quadrotor drone) motivated by the Nonlinear Model Predictive Control (NMPC) method. Unlike NMPC, the proposed method employs a closed-loop system dynamics model within the optimization problem to [...] Read more.

This paper presents a trajectory generation method for a nonlinear system under closed-loop control (here a quadrotor drone) motivated by the Nonlinear Model Predictive Control (NMPC) method. Unlike NMPC, the proposed method employs a closed-loop system dynamics model within the optimization problem to efficiently generate reference trajectories in real time. We call this approach the Nonlinear Model Predictive Horizon (NMPH). The closed-loop model used within NMPH employs a feedback linearization control law design to decrease the nonconvexity of the optimization problem and thus achieve faster convergence. For robust trajectory planning in a dynamically changing environment, static and dynamic obstacle constraints are supported within the NMPH algorithm. Our algorithm is applied to a quadrotor system to generate optimal reference trajectories in 3D, and several simulation scenarios are provided to validate the features and evaluate the performance of the proposed methodology. Full article

(This article belongs to the Special Issue Navigation and Control of UAVs)

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20 pages, 11009 KiB

Open AccessArticle

A Multiple Level-of-Detail 3D Data Transmission Approach for Low-Latency Remote Visualisation in Teleoperation Tasks

by Salvador Pacheco-Gutierrez, Hanlin Niu, Ipek Caliskanelli and Robert Skilton

Robotics 2021, 10(3), 89; https://doi.org/10.3390/robotics10030089 - 14 Jul 2021

Cited by 4 | Viewed by 4488

Abstract

In robotic teleoperation, the knowledge of the state of the remote environment in real time is paramount. Advances in the development of highly accurate 3D cameras able to provide high-quality point clouds appear to be a feasible solution for generating live, up-to-date virtual [...] Read more.

In robotic teleoperation, the knowledge of the state of the remote environment in real time is paramount. Advances in the development of highly accurate 3D cameras able to provide high-quality point clouds appear to be a feasible solution for generating live, up-to-date virtual environments. Unfortunately, the exceptional accuracy and high density of these data represent a burden for communications requiring a large bandwidth affecting setups where the local and remote systems are particularly geographically distant. This paper presents a multiple level-of-detail (LoD) compression strategy for 3D data based on tree-like codification structures capable of compressing a single data frame at multiple resolutions using dynamically configured parameters. The level of compression (resolution) of objects is prioritised based on: (i) placement on the scene; and (ii) the type of object. For the former, classical point cloud fitting and segmentation techniques are implemented; for the latter, user-defined prioritisation is considered. The results obtained are compared using a single LoD (whole-scene) compression technique previously proposed by the authors. Results showed a considerable improvement to the transmitted data size and updated frame rate while maintaining low distortion after decompression. Full article

(This article belongs to the Special Issue Advances in Robots for Hazardous Environments in the UK)

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19 pages, 1639 KiB

Open AccessArticle

Maxwell Points of Dynamical Control Systems Based on Vertical Rolling Disc—Numerical Solutions

by Marek Stodola, Matej Rajchl, Martin Brablc, Stanislav Frolík and Václav Křivánek

Robotics 2021, 10(3), 88; https://doi.org/10.3390/robotics10030088 - 12 Jul 2021

Cited by 2 | Viewed by 3759

Abstract

We study two nilpotent affine control systems derived from the dynamic and control of a vertical rolling disc that is a simplification of a differential drive wheeled mobile robot. For both systems, their controllable Lie algebras are calculated and optimal control problems are [...] Read more.

We study two nilpotent affine control systems derived from the dynamic and control of a vertical rolling disc that is a simplification of a differential drive wheeled mobile robot. For both systems, their controllable Lie algebras are calculated and optimal control problems are formulated, and their Hamiltonian systems of ODEs are derived using the Pontryagin maximum principle. These optimal control problems completely determine the energetically optimal trajectories between two states. Then, a novel numerical algorithm based on optimisation for finding the Maxwell points is presented and tested on these control systems. The results show that the use of such numerical methods can be beneficial in cases where common analytical approaches fail or are impractical. Full article

(This article belongs to the Section Sensors and Control in Robotics)

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16 pages, 2466 KiB

Open AccessEditor’s ChoiceArticle

Smart Cleaner: A New Autonomous Indoor Disinfection Robot for Combating the COVID-19 Pandemic

by Kaicheng Ruan, Zehao Wu and Qingsong Xu

Robotics 2021, 10(3), 87; https://doi.org/10.3390/robotics10030087 - 12 Jul 2021

Cited by 44 | Viewed by 13971

Abstract

The COVID-19 pandemic imposes an increasing demand for service robots as a substitute for humans to conduct various types of work in contaminated areas. Such work includes logistics, patient care, and disinfection, which can reduce the risk of human exposure to the highly [...] Read more.

The COVID-19 pandemic imposes an increasing demand for service robots as a substitute for humans to conduct various types of work in contaminated areas. Such work includes logistics, patient care, and disinfection, which can reduce the risk of human exposure to the highly contagious and deadly virus. This paper presents the design and development of Smart Cleaner, which is a new cost-effective autonomous indoor disinfection robot. It integrates a wheeled mobile robot platform and a hydrogen peroxide atomization device for automated disinfection operation in the complex indoor environment. Through the system integration of various hardware components and software programming, a prototype of the disinfection robot has been fabricated for experimental investigation. A simulation study of the drymist hydrogen peroxide disinfection model was carried out to understand the diffusion of disinfectant in a room environment. The effectiveness of the developed robot was verified in practical scenarios, such as hospital, hotel, office, and laboratory. The effect of disinfection was validated by a qualified third-party testing agency. Results demonstrate the high efficiency of the developed disinfection robot dedicated to autonomous indoor disinfection work. Full article

(This article belongs to the Special Issue Service Robotics against COVID-2019 Pandemic)

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27 pages, 7290 KiB

Open AccessArticle

Simulating Ionising Radiation in Gazebo for Robotic Nuclear Inspection Challenges

by Thomas Wright, Andrew West, Mauro Licata, Nick Hawes and Barry Lennox

Robotics 2021, 10(3), 86; https://doi.org/10.3390/robotics10030086 - 7 Jul 2021

Cited by 24 | Viewed by 7907

Abstract

The utilisation of robots in hazardous nuclear environments has potential to reduce risk to humans. However, historical use has been largely limited to specific missions rather than broader industry-wide adoption. Testing and verification of robotics in realistic scenarios is key to gaining stakeholder [...] Read more.

The utilisation of robots in hazardous nuclear environments has potential to reduce risk to humans. However, historical use has been largely limited to specific missions rather than broader industry-wide adoption. Testing and verification of robotics in realistic scenarios is key to gaining stakeholder confidence but hindered by limited access to facilities that contain radioactive materials. Simulations offer an alternative to testing with actual radioactive sources, provided they can readily describe the behaviour of robotic systems and ionising radiation within the same environment. This work presents a quick and easy way to generate simulated but realistic deployment scenarios and environments which include ionising radiation, developed to work within the popular robot operating system compatible Gazebo physics simulator. Generated environments can be evolved over time, randomly or user-defined, to simulate the effects of degradation, corrosion or to alter features of certain objects. Interaction of gamma radiation sources within the environment, as well as the response of simulated detectors attached to mobile robots, is verified against the MCNP6 Monte Carlo radiation transport code. The benefits these tools provide are highlighted by inclusion of three real-world nuclear sector environments, providing the robotics community with opportunities to assess the capabilities of robotic systems and autonomous functionalities. Full article

(This article belongs to the Special Issue Advances in Robots for Hazardous Environments in the UK)

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24 pages, 5860 KiB

Open AccessArticle

Robot-Assisted Glovebox Teleoperation for Nuclear Industry

by Ozan Tokatli, Pragna Das, Radhika Nath, Luigi Pangione, Alessandro Altobelli, Guy Burroughes, Emil T. Jonasson, Matthew F. Turner and Robert Skilton

Robotics 2021, 10(3), 85; https://doi.org/10.3390/robotics10030085 - 3 Jul 2021

Cited by 26 | Viewed by 8309

Abstract

The nuclear industry has some of the most extreme environments in the world, with radiation levels and extremely harsh conditions restraining human access to many facilities. One method for enabling minimal human exposure to hazards under these conditions is through the use of [...] Read more.

The nuclear industry has some of the most extreme environments in the world, with radiation levels and extremely harsh conditions restraining human access to many facilities. One method for enabling minimal human exposure to hazards under these conditions is through the use of gloveboxes that are sealed volumes with controlled access for performing handling. While gloveboxes allow operators to perform complex handling tasks, they put operators at considerable risk from breaking the confinement and, historically, serious examples including punctured gloves leading to lifetime doses have occurred. To date, robotic systems have had relatively little impact on the industry, even though it is clear that they offer major opportunities for improving productivity and significantly reducing risks to human health. This work presents the challenges of robotic and AI solutions for nuclear gloveboxes, and introduces a step forward for bringing cutting-edge technology to gloveboxes. The problem statement and challenges are highlighted and then an integrated demonstrator is proposed for robotic handling in nuclear gloveboxes for nuclear material handling. The proposed approach spans from tele-manipulation to shared autonomy, computer vision solutions for robotic manipulation to machine learning solutions for condition monitoring. Full article

(This article belongs to the Special Issue Advances in Robots for Hazardous Environments in the UK)

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20 pages, 1579 KiB

Open AccessArticle

Model Predictive Control for Cooperative Transportation with Feasibility-Aware Policy

by Badr Elaamery, Massimo Pesavento, Teresa Aldovini, Nicola Lissandrini, Giulia Michieletto and Angelo Cenedese

Robotics 2021, 10(3), 84; https://doi.org/10.3390/robotics10030084 - 30 Jun 2021

Cited by 4 | Viewed by 5887

Abstract

The transportation of large payloads can be made possible with Multi-Robot Systems (MRS) implementing cooperative strategies. In this work, we focus on the coordinated MRS trajectory planning task exploiting a Model Predictive Control (MPC) framework addressing both the acting robots and the transported [...] Read more.

The transportation of large payloads can be made possible with Multi-Robot Systems (MRS) implementing cooperative strategies. In this work, we focus on the coordinated MRS trajectory planning task exploiting a Model Predictive Control (MPC) framework addressing both the acting robots and the transported load. In this context, the main challenge is the possible occurrence of a temporary mismatch among agents’ actions with consequent formation errors that can cause severe damage to the carried load. To mitigate this risk, the coordination scheme may leverage a leader–follower approach, in which a hierarchical strategy is in place to trade-off between the task accomplishment and the dynamics and environment constraints. Nonetheless, particularly in narrow spaces or cluttered environments, the leader’s optimal choice may lead to trajectories that are infeasible for the follower and the load. To this aim, we propose a feasibility-aware leader–follower strategy, where the leader computes a reference trajectory, and the follower accounts for its own and the load constraints; moreover, the follower is able to communicate the trajectory infeasibility to the leader, which reacts by temporarily switching to a conservative policy. The consistent MRS co-design is allowed by the MPC formulation, for both the leader and the follower: here, the prediction capability of MPC is key to guarantee a correct and efficient execution of the leader–follower coordinated action. The approach is formally stated and discussed, and a numerical campaign is conducted to validate and assess the proposed scheme, with respect to different scenarios with growing complexity. Full article

(This article belongs to the Topic Motion Planning and Control for Robotics)

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20 pages, 9326 KiB

Open AccessArticle

Effects of Temperature and Mounting Configuration on the Dynamic Parameters Identification of Industrial Robots

by Andrea Raviola, Roberto Guida, Andrea De Martin, Stefano Pastorelli, Stefano Mauro and Massimo Sorli

Robotics 2021, 10(3), 83; https://doi.org/10.3390/robotics10030083 - 29 Jun 2021

Cited by 22 | Viewed by 5650

Abstract

Dynamic parameters are crucial for the definition of high-fidelity models of industrial manipulators. However, since they are often partially unknown, a mathematical model able to identify them is discussed and validated with the UR3 and the UR5 collaborative robots from Universal Robots. According [...] Read more.

Dynamic parameters are crucial for the definition of high-fidelity models of industrial manipulators. However, since they are often partially unknown, a mathematical model able to identify them is discussed and validated with the UR3 and the UR5 collaborative robots from Universal Robots. According to the acquired experimental data, this procedure allows for reducing the error on the estimated joint torques of about 90% with respect to the one obtained using only the information provided by the manufacturer. The present research also highlights how changes in the robot operating conditions affect its dynamic behavior. In particular, the identification process has been applied to a data set obtained commanding the same trajectory multiple times to both robots under rising joints temperatures. Average reductions of the viscous friction coefficients of about 20% and 17% for the UR3 and the UR5 robots, respectively, have been observed. Moreover, it is shown how the manipulator mounting configuration affects the number of the base dynamic parameters necessary to properly estimate the robots’ joints torques. The ability of the proposed model to take into account different mounting configurations is then verified by performing the identification procedure on a data set generated through a digital twin of a UR5 robot mounted on the ceiling. Full article

(This article belongs to the Topic Industrial Robotics)

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Robotics, Volume 10, Issue 3 (September 2021) – 26 articles

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