Next Issue
Volume 8, March
Previous Issue
Volume 7, September
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
5.9
3.7
Journals
Robotics
Volume 7
Issue 4
share announcement

Robotics, Volume 7, Issue 4 (December 2018) – 21 articles

Cover Story (view full-size image): Dual-axis tilting propellers quadcopter allows three actuations, gyroscopic torques, vectoring, and differential thrusting. Unlike the standard quadcopter, the dual-axis titling quadcopter provides a wide range of control torques by combining the three actuations. Standard quadcopters cannot fly between adjacent obstacles if one of the rotors fails. This paper proposes a bespoke concept to enhance the performance characteristics of the standard quadcopter. The proposed dual-axis tilting quadcopter has better agility and disturbance rejection ability, and performs autonomous flight between adjacent obstacles. It is also capable of flying in the event of the failure of one or two rotors. The dual-axis tilting propellers quadcopter fills the knowledge gap in the main body of the multi-rotors unmanned aerial systems research. View this paper.
  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Section
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
14 pages, 5553 KiB  
Article
Design and Experiments of a Novel Humanoid Robot with Parallel Architectures
by Matteo Russo, Daniele Cafolla and Marco Ceccarelli
Robotics 2018, 7(4), 79; https://doi.org/10.3390/robotics7040079 - 04 Dec 2018
Cited by 26 | Viewed by 8082
Abstract
In this paper, the mechanical design of the LARMbot 2, a low-cost user-oriented humanoid robot was presented. LARMbot 2 is characterized by parallel architectures for both the torso and legs. The proposed design was presented with the kinematics of its main parts—legs, torso, [...] Read more.
In this paper, the mechanical design of the LARMbot 2, a low-cost user-oriented humanoid robot was presented. LARMbot 2 is characterized by parallel architectures for both the torso and legs. The proposed design was presented with the kinematics of its main parts—legs, torso, arms—and then compared to its previous version, which was characterized by a different leg mechanism, to highlight the advantages of the latest design. A prototype was then presented, with constructive details of its subsystems and its technical specifications. To characterize the performance of the proposed robot, experimental results were presented for both the walking and weight-lifting operations. Full article
(This article belongs to the Special Issue Mechanism Design for Robotics)
►▼ Show Figures

Figure 1

1 pages, 144 KiB  
Erratum
Erratum: Shore, L. et al., Technology Acceptance and User-Centred Design of Assistive Exoskeletons for Older Adults: A Commentary. Robotics, 2018, 7, 3
by Linda Shore, Valerie Power, Adam De Eyto and Leonard W. O’Sullivan
Robotics 2018, 7(4), 78; https://doi.org/10.3390/robotics7040078 - 01 Dec 2018
Cited by 19 | Viewed by 3892
Abstract
The authors wish to make the following correction to a citation to paper [1]:[...] Full article
15 pages, 1344 KiB  
Article
Sparse in the Time Stabilization of a Bicycle Robot Model: Strategies for Event- and Self-Triggered Control Approaches
by Joanna Zietkiewicz, Dariusz Horla and Adam Owczarkowski
Robotics 2018, 7(4), 77; https://doi.org/10.3390/robotics7040077 - 28 Nov 2018
Cited by 5 | Viewed by 5044
Abstract
In this paper, the problems of event- and self-triggered control are studied for a nonlinear bicycle robot model. It has been shown that by applying control techniques based on triggering conditions, it is possible to reduce both state-based performance index, as well as [...] Read more.
In this paper, the problems of event- and self-triggered control are studied for a nonlinear bicycle robot model. It has been shown that by applying control techniques based on triggering conditions, it is possible to reduce both state-based performance index, as well as the number of triggers, in comparison to a standard linear-quadratic control which consumes less energy of the control system and decreases the potential mechanical wear of the robot parts. The results presented in this paper open a new research field for further studies, as discussed in the Summary section, and form the basis for further research in energy-efficient control techniques for stabilizing a bicycle robot. Full article
►▼ Show Figures

Figure 1

29 pages, 10948 KiB  
Article
Motion Planning and Reactive Control Algorithms for Object Manipulation in Uncertain Conditions
by Marco Costanzo, Giuseppe De Maria, Gaetano Lettera, Ciro Natale and Salvatore Pirozzi
Robotics 2018, 7(4), 76; https://doi.org/10.3390/robotics7040076 - 27 Nov 2018
Cited by 4 | Viewed by 6301
Abstract
This work proposes the application of several smart strategies for object manipulation tasks. A real-time flexible motion planning method was developed to be adapted to typical in-store logistics scenarios. The solution combines and optimizes some state-of-the-art techniques to solve object recognition and localization [...] Read more.
This work proposes the application of several smart strategies for object manipulation tasks. A real-time flexible motion planning method was developed to be adapted to typical in-store logistics scenarios. The solution combines and optimizes some state-of-the-art techniques to solve object recognition and localization problems with a new hybrid pipeline. The algorithm guarantees good robustness and accuracy for object detection through depth images. A standard planner plans collision-free trajectories throughout the whole task while a proposed reactive motion control is active. Distributed proximity sensors were adopted to locally modify the planned trajectory when unexpected or misplaced obstacles intervene in the scene. To implement a robust grasping phase, a novel slipping control algorithm was used. It dynamically computes the grasp force by adapting it to the actual object physical properties so as to prevent slipping. Experimental results carried out in a typical supermarket scenario demonstrate the effectiveness of the presented methods. Full article
(This article belongs to the Special Issue Applied Intelligent Robot for Uncertain Environments)
►▼ Show Figures

Figure 1

8 pages, 3067 KiB  
Technical Note
Nominal Stiffness of GT-2 Rubber-Fiberglass Timing Belts for Dynamic System Modeling and Design
by Bozun Wang, Yefei Si, Charul Chadha, James T. Allison and Albert E. Patterson
Robotics 2018, 7(4), 75; https://doi.org/10.3390/robotics7040075 - 21 Nov 2018
Viewed by 10774
Abstract
GT-style rubber-fiberglass (RF) timing belts are designed to effectively transfer rotational motion from pulleys to linear motion in robots, small machines, and other important mechatronic systems. One of the characteristics of belts under this type of loading condition is that the length between [...] Read more.
GT-style rubber-fiberglass (RF) timing belts are designed to effectively transfer rotational motion from pulleys to linear motion in robots, small machines, and other important mechatronic systems. One of the characteristics of belts under this type of loading condition is that the length between load and pulleys changes during operation, thereby changing their effective stiffness. It has been shown that the effective stiffness of such a belt is a function of a “nominal stiffness” and the real-time belt section lengths. However, this nominal stiffness is not necessarily constant; it is common to assume linear proportional stiffness, but this often results in system modeling error. This technical note describes a brief study where the nominal stiffness of two lengths ( 400 m m and 760 m m ) of GT-2 RF timing belt was tested up to breaking point; regression analysis was performed on the results to best model the observed stiffness. The experiments were performed three times, providing a total of six stiffness curves. It was found that cubic regression mod els ( R 2 > 0.999 ) were the best fit, but that quadratic and linear models still provided acceptable representations of the whole dataset with R 2 values above 0.940 . Full article
(This article belongs to the Special Issue Kinematics and Robot Design I, KaRD2018)
►▼ Show Figures

Figure 1

26 pages, 301 KiB  
Review
Multi-Modal Sensing and Robotic Manipulation of Non-Rigid Objects: A Survey
by Félix Nadon, Angel J. Valencia and Pierre Payeur
Robotics 2018, 7(4), 74; https://doi.org/10.3390/robotics7040074 - 20 Nov 2018
Cited by 43 | Viewed by 8948
Abstract
This paper aims to provide a comprehensive survey of recent advancements in modelling and autonomous manipulation of non-rigid objects. It first summarizes the recent advances in sensing and modelling of such objects with a focus on describing the methods and technologies used to [...] Read more.
This paper aims to provide a comprehensive survey of recent advancements in modelling and autonomous manipulation of non-rigid objects. It first summarizes the recent advances in sensing and modelling of such objects with a focus on describing the methods and technologies used to measure their shape and estimate their material and physical properties. Formal representations considered to predict the deformation resulting from manipulation of non-rigid objects are then investigated. The third part provides a survey of planning and control strategies exploited to operate dexterous robotic systems while performing various tasks on objects made of different non-rigid materials. Full article
(This article belongs to the Special Issue Feature Papers)
11 pages, 736 KiB  
Article
Vacuum-Actuated Bending for Grasping
by Jay T. Miller and Nathan Wicks
Robotics 2018, 7(4), 73; https://doi.org/10.3390/robotics7040073 - 16 Nov 2018
Cited by 1 | Viewed by 4853
Abstract
Soft robotic devices typically are actuated with the application of a positive pressure (compared to ambient pressure), but some exciting work has been done with negative pressure application, with advantages for safety and robustness. Here, we present a negative pressure bending actuator inspired [...] Read more.
Soft robotic devices typically are actuated with the application of a positive pressure (compared to ambient pressure), but some exciting work has been done with negative pressure application, with advantages for safety and robustness. Here, we present a negative pressure bending actuator inspired by previous work by Yang et al., fabricated using rapid prototyping techniques and elastomeric polymers. We describe the mechanical behavior of the system from a cellular solids perspective, showing the steps needed for the analysis and characterization of future similar systems. We find good agreement between experimentally measured values of displacement and force generated in atmospheric pressure conditions. Full article
(This article belongs to the Special Issue Soft Machines: Integrating Sensing, Actuation and Computation)
►▼ Show Figures

Graphical abstract

21 pages, 17344 KiB  
Article
Novel Design and Position Control Strategy of a Soft Robot Arm
by Alaa Al-Ibadi, Samia Nefti-Meziani, Steve Davis and Theo Theodoridis
Robotics 2018, 7(4), 72; https://doi.org/10.3390/robotics7040072 - 13 Nov 2018
Cited by 17 | Viewed by 8455
Abstract
This article presents a novel design of a continuum arm, which has the ability to extend and bend efficiently. Numerous designs and experiments have been done to different dimensions on both types of McKibben pneumatic muscle actuators (PMA) in order to study their [...] Read more.
This article presents a novel design of a continuum arm, which has the ability to extend and bend efficiently. Numerous designs and experiments have been done to different dimensions on both types of McKibben pneumatic muscle actuators (PMA) in order to study their performances. The contraction and extension behaviour have been illustrated with single contractor actuators and single extensor actuators, respectively. The tensile force for the contractor actuator and the compressive force for the extensor PMA are thoroughly explained and compared. Furthermore, the bending behaviour has been explained for a single extensor PMA, multi extensor actuators and multi contractor actuators. A two-section continuum arm has been implemented from both types of actuators to achieve multiple operations. Then, a novel construction is proposed to achieve efficient bending behaviour of a single contraction PMA. This novel design of a bending-actuator has been used to modify the presented continuum arm. Two different position control strategies are presented, arising from the results of the modified soft robot arm experiment. A cascaded position control is applied to control the position of the end effector of the soft arm at no load by efficiently controlling the pressure of all the actuators in the continuum arm. A new algorithm is then proposed by distributing the x, y and z-axis to the actuators and applying an effective closed-loop position control to the proposed arm at different load conditions. Full article
►▼ Show Figures

Figure 1

15 pages, 8523 KiB  
Article
A Vision-Based Neural Network Controller for the Autonomous Landing of a Quadrotor on Moving Targets
by Abdullah M. Almeshal and Mohammad R. Alenezi
Robotics 2018, 7(4), 71; https://doi.org/10.3390/robotics7040071 - 13 Nov 2018
Cited by 26 | Viewed by 6283
Abstract
Time constraints is the most critical factor that faces the first responders’ teams for search and rescue operations during the aftermath of natural disasters and hazardous areas. The utilization of robotic solutions to speed up search missions would help save the lives of [...] Read more.
Time constraints is the most critical factor that faces the first responders’ teams for search and rescue operations during the aftermath of natural disasters and hazardous areas. The utilization of robotic solutions to speed up search missions would help save the lives of humans who are in need of help as quickly as possible. With such a human-robot collaboration, by using autonomous robotic solutions, the first response team will be able to locate the causalities and possible victims in order to be able to drop emergency kits at their locations. This paper presents a design of vision-based neural network controller for the autonomous landing of a quadrotor on fixed and moving targets for Maritime Search and Rescue applications. The proposed controller does not require prior information about the target location and depends entirely on the vision system to estimate the target positions. Simulations of the proposed controller are presented using ROS Gazebo environment and are validated experimentally in the laboratory using a Parrot AR Drone system. The simulation and experimental results show the successful control of the quadrotor in autonomously landing on both fixed and moving landing platforms. Full article
►▼ Show Figures

Figure 1

17 pages, 275 KiB  
Article
Sexbots: Customizing Them to Suit Us versus an Ethical Duty to Created Sentient Beings to Minimize Suffering
by Robin Mackenzie
Robotics 2018, 7(4), 70; https://doi.org/10.3390/robotics7040070 - 11 Nov 2018
Cited by 14 | Viewed by 18189
Abstract
Sex robot scholarship typically focuses on customizable simulacra, lacking sentience and self-awareness but able to simulate and stimulate human affection. This paper argues that future humans will want more: sex robots customized to possess sentience and self-awareness [henceforth, sexbots], capable of mutuality in [...] Read more.
Sex robot scholarship typically focuses on customizable simulacra, lacking sentience and self-awareness but able to simulate and stimulate human affection. This paper argues that future humans will want more: sex robots customized to possess sentience and self-awareness [henceforth, sexbots], capable of mutuality in sexual and intimate relationships. Adopting a transdisciplinary critical methodology focused on the legal, ethical and design implications of sexbots, it assesses implications of sexbots’ non-mammalian subjectivity, balancing designed-in autonomy and control, decision-making capacity and consent, sexual preferences and desire, legal and moral status, vulnerability and contrasts between mammalian and non-mammalian moral decision-making. It explores theoretical, ethical, and pragmatic aspects of the tensions involved in creating sentient beings for utilitarian purposes, concluding that sexbots, customized manufactured humanlike entities with the capacity for thought and suffering, have a consequent claim to be considered moral and legal persons, and may become the first conscious robots. Customizing sexbots thus exemplifies many profound ethical, legal and design issues. The contradictions inherent in their inconsistent ethical and legal status as both manufactured things and sentient, self-aware entities who are customized to be our intimate partners augments existing human/animal scholars’ call for a new theoretical framework which supersedes current person/thing dichotomies governing human responsibilities to other sentient beings. The paper concludes that the ethical limits and legal implications of customizable humanlike robots must be addressed urgently, proposing a duty on humans as creators to safeguard the interests and minimize the suffering of created sentient beings before technological advances pre-empt this possibility. Full article
(This article belongs to the Special Issue Love and Sex with Robot)
29 pages, 11825 KiB  
Article
A Methodology for Multi-Camera Surface-Shape Estimation of Deformable Unknown Objects
by Evgeny Nuger and Beno Benhabib
Robotics 2018, 7(4), 69; https://doi.org/10.3390/robotics7040069 - 11 Nov 2018
Cited by 1 | Viewed by 5178
Abstract
A novel methodology is proposed herein to estimate the three-dimensional (3D) surface shape of unknown, markerless deforming objects through a modular multi-camera vision system. The methodology is a generalized formal approach to shape estimation for a priori unknown objects. Accurate shape estimation is [...] Read more.
A novel methodology is proposed herein to estimate the three-dimensional (3D) surface shape of unknown, markerless deforming objects through a modular multi-camera vision system. The methodology is a generalized formal approach to shape estimation for a priori unknown objects. Accurate shape estimation is accomplished through a robust, adaptive particle filtering process. The estimation process yields a set of surface meshes representing the expected deformation of the target object. The methodology is based on the use of a multi-camera system, with a variable number of cameras, and range of object motions. The numerous simulations and experiments presented herein demonstrate the proposed methodology’s ability to accurately estimate the surface deformation of unknown objects, as well as its robustness to object loss under self-occlusion, and varying motion dynamics. Full article
►▼ Show Figures

Figure 1

12 pages, 3504 KiB  
Article
Adaptive Balancing of Robots and Mechatronic Systems
by Liviu Ciupitu
Robotics 2018, 7(4), 68; https://doi.org/10.3390/robotics7040068 - 07 Nov 2018
Cited by 10 | Viewed by 7082
Abstract
Present paper is dealing with the adaptive static balancing of robot or other mechatronic arms that are rocking in vertical plane and whose static loads are variable, by using counterweights and springs. Some simple passive and approximate solutions are proposed, and an example [...] Read more.
Present paper is dealing with the adaptive static balancing of robot or other mechatronic arms that are rocking in vertical plane and whose static loads are variable, by using counterweights and springs. Some simple passive and approximate solutions are proposed, and an example is shown. The results show that a very simple passive solution which is using for gravity compensation a simple translational counterweight (that could be for example the actuating motor itself) articulated by one single bar leads to very good results in case of approximate balancing when the payload has a known variation. Full article
(This article belongs to the Special Issue Kinematics and Robot Design I, KaRD2018)
►▼ Show Figures

Figure 1

25 pages, 1710 KiB  
Review
Formation Control for a Fleet of Autonomous Ground Vehicles: A Survey
by Aakash Soni and Huosheng Hu
Robotics 2018, 7(4), 67; https://doi.org/10.3390/robotics7040067 - 01 Nov 2018
Cited by 54 | Viewed by 11542
Abstract
Autonomous/unmanned driving is the major state-of-the-art step that has a potential to fundamentally transform the mobility of individuals and goods. At present, most of the developments target standalone autonomous vehicles, which can sense the surroundings and control the vehicle based on this perception, [...] Read more.
Autonomous/unmanned driving is the major state-of-the-art step that has a potential to fundamentally transform the mobility of individuals and goods. At present, most of the developments target standalone autonomous vehicles, which can sense the surroundings and control the vehicle based on this perception, with limited or no driver intervention. This paper focuses on the next step in autonomous vehicle research, which is the collaboration between autonomous vehicles, mainly vehicle formation control or vehicle platooning. To gain a deeper understanding in this area, a large number of the existing published papers have been reviewed systemically. In other words, many distributed and decentralized approaches of vehicle formation control are studied and their implementations are discussed. Finally, both technical and implementation challenges for formation control are summarized. Full article
(This article belongs to the Special Issue Feature Papers)
►▼ Show Figures

Figure 1

22 pages, 810 KiB  
Article
Model-Free Gradient-Based Adaptive Learning Controller for an Unmanned Flexible Wing Aircraft
by Mohammed Abouheaf, Wail Gueaieb and Frank Lewis
Robotics 2018, 7(4), 66; https://doi.org/10.3390/robotics7040066 - 23 Oct 2018
Cited by 16 | Viewed by 5481
Abstract
Classical gradient-based approximate dynamic programming approaches provide reliable and fast solution platforms for various optimal control problems. However, their dependence on accurate modeling approaches poses a major concern, where the efficiency of the proposed solutions are severely degraded in the case of uncertain [...] Read more.
Classical gradient-based approximate dynamic programming approaches provide reliable and fast solution platforms for various optimal control problems. However, their dependence on accurate modeling approaches poses a major concern, where the efficiency of the proposed solutions are severely degraded in the case of uncertain dynamical environments. Herein, a novel online adaptive learning framework is introduced to solve action-dependent dual heuristic dynamic programming problems. The approach does not depend on the dynamical models of the considered systems. Instead, it employs optimization principles to produce model-free control strategies. A policy iteration process is employed to solve the underlying Hamilton–Jacobi–Bellman equation using means of adaptive critics, where a layer of separate actor-critic neural networks is employed along with gradient descent adaptation rules. A Riccati development is introduced and shown to be equivalent to solving the underlying Hamilton–Jacobi–Bellman equation. The proposed approach is applied on the challenging weight shift control problem of a flexible wing aircraft. The continuous nonlinear deformation in the aircraft’s flexible wing leads to various aerodynamic variations at different trim speeds, which makes its auto-pilot control a complicated task. Series of numerical simulations were carried out to demonstrate the effectiveness of the suggested strategy. Full article
(This article belongs to the Special Issue Feature Papers)
►▼ Show Figures

Figure 1

20 pages, 6006 KiB  
Article
Design and Implementation of a Dual-Axis Tilting Quadcopter
by Ali Bin Junaid, Alejandro Diaz De Cerio Sanchez, Javier Betancor Bosch, Nikolaos Vitzilaios and Yahya Zweiri
Robotics 2018, 7(4), 65; https://doi.org/10.3390/robotics7040065 - 20 Oct 2018
Cited by 34 | Viewed by 12584
Abstract
Standard quadcopters are popular largely because of their mechanical simplicity relative to other hovering aircraft, low cost and minimum operator involvement. However, this simplicity imposes fundamental limits on the types of maneuvers possible due to its under-actuation. The dexterity and fault tolerance required [...] Read more.
Standard quadcopters are popular largely because of their mechanical simplicity relative to other hovering aircraft, low cost and minimum operator involvement. However, this simplicity imposes fundamental limits on the types of maneuvers possible due to its under-actuation. The dexterity and fault tolerance required for flying in limited spaces like forests and industrial infrastructures dictate the use of a bespoke dual-tilting quadcopter that can launch vertically, performs autonomous flight between adjacent obstacles and is even capable of flying in the event of the failure of one or two motors. This paper proposes an actuation concept to enhance the performance characteristics of the conventional under-actuated quadcopter. The practical formation of this concept is followed by the design, modeling, simulation and prototyping of a dual-axis tilting quadcopter. Outdoor flight tests using tilting rotors, to follow a trajectory containing adjacent obstacles, were conducted in order to compare the flight of conventional quadcopter with the proposed over-actuated vehicle. The results show that the quadcopter with tilting rotors provides more agility and mobility to the vehicle especially in narrow indoor and outdoor infrastructures. Full article
(This article belongs to the Special Issue Kinematics and Robot Design I, KaRD2018)
►▼ Show Figures

Graphical abstract

24 pages, 1575 KiB  
Article
Spacecraft Robot Kinematics Using Dual Quaternions
by Alfredo Valverde and Panagiotis Tsiotras
Robotics 2018, 7(4), 64; https://doi.org/10.3390/robotics7040064 - 12 Oct 2018
Cited by 17 | Viewed by 7718
Abstract
In recent years, there has been a growing interest in servicing orbiting satellites. In most cases, in-orbit servicing relies on the use of spacecraft-mounted robotic manipulators to carry out complicated mission objectives. Dual quaternions, a mathematical tool to conveniently represent pose, has recently [...] Read more.
In recent years, there has been a growing interest in servicing orbiting satellites. In most cases, in-orbit servicing relies on the use of spacecraft-mounted robotic manipulators to carry out complicated mission objectives. Dual quaternions, a mathematical tool to conveniently represent pose, has recently been adopted within the space industry to tackle complex control problems during the stages of proximity operations and rendezvous, as well as for the dynamic modeling of robotic arms mounted on a spacecraft. The objective of this paper is to bridge the gap in the use of dual quaternions that exists between the fields of spacecraft control and fixed-base robotic manipulation. In particular, we will cast commonly used tools in the field of robotics as dual quaternion expressions, such as the Denavit-Hartenberg parameterization, or the product of exponentials formula. Additionally, we provide, via examples, a study of the kinematics of different serial manipulator configurations, building up to the case of a completely free-floating robotic system. We provide expressions for the dual velocities of the different types of joints that commonly arise in industrial robots, and we end by providing a collection of results that cast convex constraints commonly encountered by space robots during proximity operations in terms of dual quaternions. Full article
(This article belongs to the Special Issue Kinematics and Robot Design I, KaRD2018)
►▼ Show Figures

Figure 1

12 pages, 3696 KiB  
Article
Leaf Area Estimation of Reconstructed Maize Plants Using a Time-of-Flight Camera Based on Different Scan Directions
by Manuel Vázquez-Arellano, David Reiser, Dimitrios S. Paraforos, Miguel Garrido-Izard and Hans W. Griepentrog
Robotics 2018, 7(4), 63; https://doi.org/10.3390/robotics7040063 - 11 Oct 2018
Cited by 13 | Viewed by 5997
Abstract
The leaf area is an important plant parameter for plant status and crop yield. In this paper, a low-cost time-of-flight camera, the Kinect v2, was mounted on a robotic platform to acquire 3-D data of maize plants in a greenhouse. The robotic platform [...] Read more.
The leaf area is an important plant parameter for plant status and crop yield. In this paper, a low-cost time-of-flight camera, the Kinect v2, was mounted on a robotic platform to acquire 3-D data of maize plants in a greenhouse. The robotic platform drove through the maize rows and acquired 3-D images that were later registered and stitched. Three different maize row reconstruction approaches were compared: reconstruct a crop row by merging point clouds generated from both sides of the row in both directions, merging point clouds scanned just from one side, and merging point clouds scanned from opposite directions of the row. The resulted point cloud was subsampled and rasterized, the normals were computed and re-oriented with a Fast Marching algorithm. The Poisson surface reconstruction was applied to the point cloud, and new vertices and faces generated by the algorithm were removed. The results showed that the approach of aligning and merging four point clouds per row and two point clouds scanned from the same side generated very similar average mean absolute percentage error of 8.8% and 7.8%, respectively. The worst error resulted from the two point clouds scanned from both sides in opposite directions with 32.3%. Full article
(This article belongs to the Special Issue Agricultural and Field Robotics)
►▼ Show Figures

Figure 1

20 pages, 505 KiB  
Article
Beyond the Sex Doll: Post-Human Companionship and the Rise of the ‘Allodoll’
by Mitchell Langcaster-James and Gillian R Bentley
Robotics 2018, 7(4), 62; https://doi.org/10.3390/robotics7040062 - 08 Oct 2018
Cited by 32 | Viewed by 33609
Abstract
The increasing market for realistic sex dolls has led to heated debate about future relationships with these entities and whether they could lead to an increasing objectification of women or possibly encourage abuse. However, limited academic research has been carried out on the [...] Read more.
The increasing market for realistic sex dolls has led to heated debate about future relationships with these entities and whether they could lead to an increasing objectification of women or possibly encourage abuse. However, limited academic research has been carried out on the topic, and little is known about the motivations and experiences of those who purchase and use sex dolls. Therefore, we conducted a mixed methods study of 83 participants, accessed through online doll forums, who completed a 22-item, semi-structured questionnaire. The majority were heterosexual, white, employed, middle-aged males; just over half were not in a current relationship, and approximately half lived alone. A thematic analysis revealed a high prevalence of non-sexual, post-human companionship dynamics between dolls and their owners, as well as reservations by doll owners about future robotic developments. In light of these findings, we suggest a new term, ‘allodoll’, which more accurately reflects the broader, non-sexual relationships of these doll owners, and could broaden the scope of future research. Although sex doll forums may be biased towards certain types of doll users, our findings may allay some of the fears of the more detrimental consequences of sex doll use. Full article
(This article belongs to the Special Issue Love and Sex with Robot)
►▼ Show Figures

Figure 1

15 pages, 9909 KiB  
Article
A Novel Multirobot System for Plant Phenotyping
by Tianshuang Gao, Hamid Emadi, Homagni Saha, Jiaoping Zhang, Alec Lofquist, Arti Singh, Baskar Ganapathysubramanian, Soumik Sarkar, Asheesh K. Singh and Sourabh Bhattacharya
Robotics 2018, 7(4), 61; https://doi.org/10.3390/robotics7040061 - 26 Sep 2018
Cited by 26 | Viewed by 7581
Abstract
Phenotypic studies require large datasets for accurate inference and prediction. Collecting plant data in a farm can be very labor intensive and costly. This paper presents the design, architecture (hardware and software) and deployment of a multi-robot system for row crop field data [...] Read more.
Phenotypic studies require large datasets for accurate inference and prediction. Collecting plant data in a farm can be very labor intensive and costly. This paper presents the design, architecture (hardware and software) and deployment of a multi-robot system for row crop field data collection. The proposed system has been deployed in a soybean research farm at Iowa State University. Full article
(This article belongs to the Special Issue Agricultural and Field Robotics)
►▼ Show Figures

Figure 1

13 pages, 1945 KiB  
Article
Non-Linear Lumped-Parameter Modeling of Planar Multi-Link Manipulators with Highly Flexible Arms
by Ivan Giorgio and Dionisio Del Vescovo
Robotics 2018, 7(4), 60; https://doi.org/10.3390/robotics7040060 - 25 Sep 2018
Cited by 38 | Viewed by 7215
Abstract
The problem of the trajectory-tracking and vibration control of highly flexible planar multi-links robot arms is investigated. We discretize the links according to the Hencky bar-chain model, which is an application of the lumped parameters techniques. In this approach, each link is considered [...] Read more.
The problem of the trajectory-tracking and vibration control of highly flexible planar multi-links robot arms is investigated. We discretize the links according to the Hencky bar-chain model, which is an application of the lumped parameters techniques. In this approach, each link is considered as a kinematic chain of rigid bodies, and suitable springs are added in order to model bending resistance. The control strategy employed is based on an optimal input pre-shaping and a feedback of the joint angles to treat the effects of undesired disturbances. Some numerical examples are given to show the potentialities of the proposed control, and a comparison with a standard collocated Proportional-Derivative (PD) control strategy is performed. In particular, we study the cases of a linear and a parabolic trajectory with a polynomial time law chosen to minimize the onset of possible vibrations. Full article
(This article belongs to the Special Issue Kinematics and Robot Design I, KaRD2018)
►▼ Show Figures

Figure 1

13 pages, 2530 KiB  
Article
Kinematics Analysis of a Class of Spherical PKMs by Projective Angles
by Giovanni Legnani and Irene Fassi
Robotics 2018, 7(4), 59; https://doi.org/10.3390/robotics7040059 - 20 Sep 2018
Cited by 6 | Viewed by 5171
Abstract
This paper presents the kinematics analysis of a class of spherical PKMs Parallel Kinematics Machines exploiting a novel approach. The analysis takes advantage of the properties of the projective angles, which are a set of angular conventions of which their properties have only [...] Read more.
This paper presents the kinematics analysis of a class of spherical PKMs Parallel Kinematics Machines exploiting a novel approach. The analysis takes advantage of the properties of the projective angles, which are a set of angular conventions of which their properties have only recently been presented. Direct, inverse kinematics and singular configurations are discussed. The analysis, which results in the solution of easy equations, is developed at position, velocity and acceleration level. Full article
(This article belongs to the Special Issue Kinematics and Robot Design I, KaRD2018)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-21
Previous Issue
Next Issue
Back to TopTop