Research

21 pages, 11951 KiB

Open AccessArticle

A Control Architecture for Developing Reactive Hybrid Remotely Operated Underwater Vehicles

by Fernando Gómez-Bravo, Alejandro Garrocho-Cruz, Olga Marín-Cañas, Inmaculada Pulido-Calvo, Juan Carlos Gutierrez-Estrada and Antonio Peregrín-Rubio

Machines 2024, 12(1), 1; https://doi.org/10.3390/machines12010001 - 19 Dec 2023

Viewed by 1011

Abstract

This article introduces a control architecture designed for the development of Hybrid Remotely Operated Underwater Vehicles. The term ”Hybrid” characterizes Remotely Operated systems capable of autonomously executing specific operations. The presented architecture maintains teleoperation capabilities while enabling two fully autonomous applications. The approach [...] Read more.

This article introduces a control architecture designed for the development of Hybrid Remotely Operated Underwater Vehicles. The term ”Hybrid” characterizes Remotely Operated systems capable of autonomously executing specific operations. The presented architecture maintains teleoperation capabilities while enabling two fully autonomous applications. The approach emphasizes the implementation of reactive navigation by exclusively utilizing data from a Mechanical Scanned Imaging Sonar for control decisions. This mandates the control system to solely react to data derived from the vehicle’s environment, without considering other positioning information or state estimation. The study involves transforming a small-scale commercial Remotely Operated Underwater Vehicle into a hybrid system without structural modifications, and details the development of an intermediate Operational Control Layer responsible for sensor data processing and task execution control. Two practical applications, inspired by tasks common in natural or open-water aquaculture farms, are explored: one for conducting transects, facilitating monitoring and maintenance operations, and another for navigating toward an object for inspection purposes. Experimental results validate the feasibility and effectiveness of the authors’ hypotheses. This approach expands the potential applications of underwater vehicles and facilitates the development of Hybrid Remotely Operated Underwater Vehicles, enabling the execution of autonomous reactive tasks. Full article

(This article belongs to the Special Issue Mobile Robotics: Mathematics, Models and Methods)

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18 pages, 15684 KiB

Open AccessArticle

Towards the Design of a User-Friendly Chimney-Cleaning Robot

by Giuliano Arcorace, Giovanni Caruso, Pietro Cavallaro, Antonio Pantaleone Paglia, Christian Sollazzo, Manuel Tripodi, Elio Matteo Curcio, Francesco Lago and Giuseppe Carbone

Machines 2023, 11(11), 1024; https://doi.org/10.3390/machines11111024 - 15 Nov 2023

Viewed by 1716

Abstract

Domestic chimney cleaning is still mostly a manual procedure which can be overly complex, dangerous, and expansive. This paper describes the design of a novel robotic device for chimney cleaning that aims to provide a valuable alternative solution to the traditional manual techniques [...] Read more.

Domestic chimney cleaning is still mostly a manual procedure which can be overly complex, dangerous, and expansive. This paper describes the design of a novel robotic device for chimney cleaning that aims to provide a valuable alternative solution to the traditional manual techniques with user-friendly and low-cost features. The proposed device enables a significant reduction in operator risks, including roof falling and soot dust contact. The paper’s content describes, in detail, the design process, including a definition of the main design requirements and steps towards the manufacturing of a preliminary prototype. Moreover, a preliminary validation is described through laboratory tests to demonstrate the engineering feasibility and effectiveness of the proposed design solution for the intended semi-autonomous chimney-cleaning application. Full article

(This article belongs to the Special Issue Mobile Robotics: Mathematics, Models and Methods)

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22 pages, 35709 KiB

Open AccessArticle

Modeling and Application of an SMA-Actuated Lightweight Human-Inspired Gripper for Aerial Manipulation

by Vicente Perez-Sanchez, Francisco Javier Garcia-Rubiales, Saeed Rafee Nekoo, Begoña Arrue and Anibal Ollero

Machines 2023, 11(9), 859; https://doi.org/10.3390/machines11090859 - 27 Aug 2023

Viewed by 1414

Abstract

The increasing usage of multi-rotor aerial platforms and the reliability of flights enabled researchers to add equipment and devices to them for application. The addition of lightweight manipulators, grippers, and mechanisms to fulfill specific tasks has been reported frequently recently. This work pushes [...] Read more.

The increasing usage of multi-rotor aerial platforms and the reliability of flights enabled researchers to add equipment and devices to them for application. The addition of lightweight manipulators, grippers, and mechanisms to fulfill specific tasks has been reported frequently recently. This work pushes the idea one step ahead and uses an Artificial Human Hand (AHH) in an uncrewed aerial vehicle for aerial manipulation, device delivery, and co-operation with human workers. This application requires an effective end-effector capable of grasping and holding objects of different shapes. The AHH is a lightweight custom-made human-inspired design actuated using Shape Memory Alloy (SMA) materials. The SMA actuators offer significantly high forces with respect to their light weights though the control of these new actuators is a challenge that has been successfully demonstrated in this paper. The control of the SMA actuators could be achieved via heat exchange on the actuator, indirectly carried out by changing the current. The benefit of using this new actuator is removing the motors and mechanical mechanisms and simplifying the design. A soft cover is developed for the AHH to add friction and make it closer to a human hand. The modeling of the structured actuators on the system through tendons is presented, and a series of experiments for handling and manipulating different objects have been conducted. The objects were chosen with different weights and shapes to show the effectiveness of the design. An analysis of a generated torque of the manipulator for different cylindrical objects has been carried out. An analysis and comparison for grasping a series of items, pressure and temperature analysis, and the weight-to-volume ratio have been presented. Full article

(This article belongs to the Special Issue Mobile Robotics: Mathematics, Models and Methods)

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17 pages, 33772 KiB

Open AccessCommunication

Waypoint Generation in Satellite Images Based on a CNN for Outdoor UGV Navigation

by Manuel Sánchez, Jesús Morales and Jorge L. Martínez

Machines 2023, 11(8), 807; https://doi.org/10.3390/machines11080807 - 06 Aug 2023

Cited by 2 | Viewed by 939

Abstract

Moving on paths or trails present in natural environments makes autonomous navigation of unmanned ground vehicles (UGV) simpler and safer. In this sense, aerial photographs provide a lot of information of wide areas that can be employed to detect paths for UGV usage. [...] Read more.

Moving on paths or trails present in natural environments makes autonomous navigation of unmanned ground vehicles (UGV) simpler and safer. In this sense, aerial photographs provide a lot of information of wide areas that can be employed to detect paths for UGV usage. This paper proposes the extraction of paths from a geo-referenced satellite image centered at the current UGV position. Its pixels are individually classified as being part of a path or not using a convolutional neural network (CNN) which has been trained using synthetic data. Then, successive distant waypoints inside the detected paths are generated to achieve a given goal. This processing has been successfully tested on the Andabata mobile robot, which follows the list of waypoints in a reactive way based on a three-dimensional (3D) light detection and ranging (LiDAR) sensor. Full article

(This article belongs to the Special Issue Mobile Robotics: Mathematics, Models and Methods)

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25 pages, 14592 KiB

Open AccessArticle

Phasor-Like Interpretation of the Angular Velocity of the Wheels of Omnidirectional Mobile Robots

by Jordi Palacín, Elena Rubies, Ricard Bitriá and Eduard Clotet

Machines 2023, 11(7), 698; https://doi.org/10.3390/machines11070698 - 01 Jul 2023

Cited by 1 | Viewed by 1628

Abstract

Omnidirectionality is a feature that allows motion in any direction without orientation maneuvers. Omnidirectional mobile robots are usually based on omni or mecanum wheels. The motion of an omnidirectional mobile robot is defined by a target motion command [...] Read more.

Omnidirectionality is a feature that allows motion in any direction without orientation maneuvers. Omnidirectional mobile robots are usually based on omni or mecanum wheels. The motion of an omnidirectional mobile robot is defined by a target motion command

M = (v, α, ω)

, where

v

is the module of the translational velocity;

α

is the angular orientation of the translational velocity, and

ω

is the angular velocity of the mobile robot. The motion is achieved by converting the target motion command into the target angular velocities that must be applied to the active wheels of the robot. This work proposes a simplified phasor-like interpretation of the relationship between the parameters of a specific motion command and the angular velocities of the wheels. The concept of phasor-like notation is validated from the analysis of the kinematics of omnidirectional mobile robots using omni wheels and mecanum wheels. This simplified phasor-like notation fosters unconstrained conceptual design of single-type and hybrid multi-wheeled omnidirectional mobile robots without the distribution or type of wheels being a design constraint. Full article

(This article belongs to the Special Issue Mobile Robotics: Mathematics, Models and Methods)

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17 pages, 5362 KiB

Open AccessArticle

Motion Law and Mechanical Properties of PIGs When Passing through a Pipe Bend

by Shengtao Chen, Lei Xia, Xiaolu Wang, Kai Teng, Yibo Zhang, Meiyu Zhang and Yongjun Gong

Machines 2022, 10(10), 963; https://doi.org/10.3390/machines10100963 - 21 Oct 2022

Cited by 1 | Viewed by 4499

Abstract

Pipeline inspection gauges (PIGs), as a kind of pipeline robot, are very efficient tools for cleaning and inspecting pipelines. However, the occurrence of obstructions in PIGs has always been a problem. The main cause of the PIG clogging pipeline problem is the reduced [...] Read more.

Pipeline inspection gauges (PIGs), as a kind of pipeline robot, are very efficient tools for cleaning and inspecting pipelines. However, the occurrence of obstructions in PIGs has always been a problem. The main cause of the PIG clogging pipeline problem is the reduced pressure differential between the front and rear due to damage to the cup. In this paper, a rigid-flexible coupled multibody dynamic motion system is established by importing flexible bodies. The stress and contact force generated by the elastic deformation of the cup in the pipe are analyzed. Moreover, the spacing ratio of PIG cups and the number of cups were changed, the number of cabin sections was increased, the bending of PIGs of different sizes and specifications was studied, and the influence of the cross-universal joint on the bending of PIGs, as well as the force between the cups and the core tube, was analyzed. Through the design and construction of the corresponding experimental equipment, the influence of the change in the number of leather cups on cornering is studied. Full article

(This article belongs to the Special Issue Mobile Robotics: Mathematics, Models and Methods)

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16 pages, 1266 KiB

Open AccessArticle

Deep Reinforcement Learning Based on Social Spatial–Temporal Graph Convolution Network for Crowd Navigation

by Yazhou Lu, Xiaogang Ruan and Jing Huang

Machines 2022, 10(8), 703; https://doi.org/10.3390/machines10080703 - 17 Aug 2022

Cited by 6 | Viewed by 1822

Abstract

In the crowd navigation, reinforcement learning based on graph neural network is a promising method, which effectively solves the poor navigation effect based on social interaction model and the freezing behavior of robot in extreme cases. However, since the information correlation of human [...] Read more.

In the crowd navigation, reinforcement learning based on graph neural network is a promising method, which effectively solves the poor navigation effect based on social interaction model and the freezing behavior of robot in extreme cases. However, since the information correlation of human trajectory has not been involved in the method, its performance still needs improvement. Therefore, we proposed a deep reinforcement learning model based on Social Spatial–Temporal Graph Convolution Network (SSTGCN) to handle the crowd navigation problem, in which the spatial–temporal information of human trajectory has been taken advantage to predict human behavior intentions and help robot plan path more efficiently. The model consists of graph learning module and robot forward planning module. In the graph learning module, the latent features of agents are taken advantage to reason about the relations among the agents, and SSTGCN is used to update feature matrix. In addition, value estimation module calculates state representation and state prediction module predicts the next state. The robot forward planning module makes use of k-step planning to estimate the quality of state and searches the best k steps planning. We tested our model in the Crowd-Nav platform, and the results show that our model has high navigation success rate and short navigation time. In addition, it has good robustness to crowd changes. Full article

(This article belongs to the Special Issue Mobile Robotics: Mathematics, Models and Methods)

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16 pages, 6175 KiB

Open AccessArticle

Robotics Navigation System for Mapping Underground Hydraulic Networks

by Carlos Hernández-Santos, Ernesto Rincon, Yasser A. Davizón, Adriana Vargas-Martínez and Alejandro R. Said

Machines 2022, 10(7), 509; https://doi.org/10.3390/machines10070509 - 23 Jun 2022

Viewed by 1447

Abstract

This paper presents the model, design, and simulation for a navigation system developed for a group of mobile robots dedicated to the production of maps for underground hydraulic infrastructure. The system can operate internally in unknown pipeline networks without GPS support, integrating Tarry’s [...] Read more.

This paper presents the model, design, and simulation for a navigation system developed for a group of mobile robots dedicated to the production of maps for underground hydraulic infrastructure. The system can operate internally in unknown pipeline networks without GPS support, integrating Tarry’s principles of deep search, Pledge modify discrimination, and topographic orientation transfer, in the temporary construction of a reference network independent of peripheral inertial navigation. The acquisition of topographic objectives for mapping is done by laser collimation and radio frequency synchronization with an angular and longitudinal precision of sigma II range. The maps produced contain the polygonal axes of the network pipelines. Full article

(This article belongs to the Special Issue Mobile Robotics: Mathematics, Models and Methods)

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