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Machines
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Machines, Mechanisms and Robots: Theory and Applications
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Machines, Mechanisms and Robots: Theory and Applications

A topical collection in Machines (ISSN 2075-1702).

Viewed by 19857

Editor

Prof. Dr. Raffaele Di Gregorio

E-Mail Website
Collection Editor
Engineering Department, University of Ferrara, 44122 Ferrara, Italy
Interests: kinematics; dynamics; mechanism and machine theory; parallel manipulators; robot mechanics; biomechanics; vehicle mechanics; robotics
Special Issues, Collections and Topics in MDPI journals

Topical Collection Information

Dear Colleagues,

Machines, Mechanisms and Robots: Theory and Applications (MMR-T&A) is an interdisciplinary collection focused on Mechanical Systems analyzed from both the theoretical and the applicative points of view. It aims to report scientific advancements in all the fields concerning mechanical system design. MMR-T&A papers are expected to make a demonstrable original contribution to engineering knowledge, which should be significant in terms of advancement over established methods. Papers that include both theoretical and experimental aspects, or that include theoretical material relevant to practical applications, are welcome.

Papers submitted to MMR-T&A should clearly state the original scientific contribution of the work, both in the “Abstract” and in the “Introduction”. In addition, the Introduction must clearly define the specific problem treated, with all conditions and assumptions made, and place the contribution in relation to both the historical literature and the state of art. The state of the art should, as much as possible, be summarized and classified—it must not be given as a mere listing of papers. The specific reasons for introducing a new method or approach should become clear based on the presented state of the art. Any advantages of proposed methods over established techniques should be explained clearly and in detail, including comparative tests and experimental evidence wherever possible.

In this collection, original research articles and reviews are welcome. Research areas may include (but are not limited to) the following:

  • Mechanism and machine theory;
  • Service and industrial robotics;
  • Autonomous systems;
  • Biomedical engineering and biomechanics;
  • Compliant mechanisms and origami-based/reconfigurable mechanisms;
  • Rotor dynamics;
  • Powertrains and drivetrains;
  • Ground, aerial and space vehicle engineering;
  • MEMS/NEMS design, technology and applications;
  • System control;
  • Multi-body dynamics;
  • Higher education on mechanical systems.

I look forward to receiving your contributions.

Prof. Dr. Raffaele Di Gregorio
Collection Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the collection website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Machines is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (9 papers)

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2024

Jump to: 2023, 2022, 2021

21 pages, 14486 KiB  
Article
Parallel Pointing Systems Suitable for Robotic Total Stations: Selection, Dimensional Synthesis, and Accuracy Analysis
by Henrique Simas, Raffaele Di Gregorio, Roberto Simoni and Marco Gatti
Machines 2024, 12(1), 54; https://doi.org/10.3390/machines12010054 - 12 Jan 2024
Viewed by 762
Abstract
Robotic Total Stations (RTS) are fully automated theodolites with electronic distance measurement (EDM) that include a number of additional tools (e.g., camera, laser rangefinder, onboard computer, and tracking software, etc.) enabling them to work autonomously. The added tools make RTSs able to track [...] Read more.
Robotic Total Stations (RTS) are fully automated theodolites with electronic distance measurement (EDM) that include a number of additional tools (e.g., camera, laser rangefinder, onboard computer, and tracking software, etc.) enabling them to work autonomously. The added tools make RTSs able to track mobile targets on civil structures thus opening to the use of RTSs in structural monitoring. Unfortunately, the available RTSs are able to track a target up to a motion rate of 3 Hz. Reducing mobile masses is a viable design strategy for extending this frequency border. Such a strategy is pursued in this study by proposing the use of parallel pointing systems (PPS) as basic mechanical architectures for RTSs. The literature on PPSs is reviewed and the applicable PPS architectures are selected. Successively, the selected architectures are sized according to RTSs’ functional requirements, and the positioning precision of the sized mechanisms is evaluated. The result of this study is that there are three PPS architectures suitable for RTSs, whose detailed comparison is also presented. Full article
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2023

Jump to: 2024, 2022, 2021

22 pages, 2641 KiB  
Article
Obstacle Avoidance in Operational Configuration Space Kinematic Control of Redundant Serial Manipulators
by Adrian Peidro and Edward J. Haug
Machines 2024, 12(1), 10; https://doi.org/10.3390/machines12010010 - 23 Dec 2023
Cited by 1 | Viewed by 939
Abstract
Kinematic control of redundant serial manipulators has been carried out for the past half century based primarily on a generalized inverse velocity formulation that is known to have mathematical deficiencies. A recently developed inverse kinematic configuration mapping is employed in an operational configuration [...] Read more.
Kinematic control of redundant serial manipulators has been carried out for the past half century based primarily on a generalized inverse velocity formulation that is known to have mathematical deficiencies. A recently developed inverse kinematic configuration mapping is employed in an operational configuration space differentiable manifold formulation for redundant-manipulator kinematic control with obstacle avoidance. This formulation is shown to resolve deficiencies in the generalized inverse velocity formulation, especially for high-degree-of-redundancy manipulators. Tracking a specified output trajectory while avoiding obstacles for four- and twenty-degree-of-redundancy manipulators is carried out to demonstrate the effectiveness of the differentiable manifold approach for applications with a high degree of redundancy and to show that it indeed resolves deficiencies of the conventional generalized inverse velocity formulation in challenging applications. Full article
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14 pages, 3459 KiB  
Article
Kinematic Analysis of a Spatial Cable-Driven Mechanism and Its Equivalent Hybrid Mechanism for Elliptical Trajectory
by Li Wu, Xuan Liu, Mingjun Wang, Dengbiao Zhao and Lewei Tang
Machines 2023, 11(7), 710; https://doi.org/10.3390/machines11070710 - 04 Jul 2023
Cited by 1 | Viewed by 979
Abstract
In this paper, a spatial cable-driven parallel mechanism in a V-shaped cable arrangement is proposed. It is further simplified as a planar hybrid cable-driven parallel mechanism to analyze its kinematics, which consists of two identical active cable chains and a passive cross-slide mechanism. [...] Read more.
In this paper, a spatial cable-driven parallel mechanism in a V-shaped cable arrangement is proposed. It is further simplified as a planar hybrid cable-driven parallel mechanism to analyze its kinematics, which consists of two identical active cable chains and a passive cross-slide mechanism. In order to investigate the degrees of freedom (DoFs) of the hybrid mechanism using screw theory, cable chains are represented as rotational–prismatic–rotational (RPR) chains. The motion pairs of all the chains are denoted according to screw theory. Firstly, the number and the types of DoFs of each chain are determined. Then, the number and the types of DoFs for the hybrid mechanism are calculated. Furthermore, the theoretical result is verified using the modified Grübler–Kutzbach (G-K) formula. It shows that the unique DoF of the equivalent mechanism is a rotation with a continuously changing axis, which is consistent with the V-type cable-driven mechanism with elliptical trajectories. Finally, the kinematics analysis of the cross-slider mechanism driven by two cables is carried out. The length, velocity and acceleration of the cables are obtained from numerical calculation in MATLAB, and the results are demonstrated using ADAMS simulation. Full article
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16 pages, 2211 KiB  
Article
Reconfiguration Analysis and Characteristics of a Novel 8-Link Variable-DOF Planar Mechanism with Five Motion Modes
by Xianwen Kong and Jieyu Wang
Machines 2023, 11(5), 529; https://doi.org/10.3390/machines11050529 - 04 May 2023
Viewed by 1274
Abstract
Variable-DOF (or kinematotropic) mechanisms are a class of reconfigurable mechanisms that have varying degrees of freedom (DOF) in different motion modes and can be reconfigured without disassembly. However, the number of proposed variable-DOF multi-loop planar mechanisms is currently limited. This paper introduces a [...] Read more.
Variable-DOF (or kinematotropic) mechanisms are a class of reconfigurable mechanisms that have varying degrees of freedom (DOF) in different motion modes and can be reconfigured without disassembly. However, the number of proposed variable-DOF multi-loop planar mechanisms is currently limited. This paper introduces a new 8-link variable-DOF planar mechanism that has five motion modes. Firstly, the 8-link variable-DOF planar mechanism is described. Then, reconfiguration analysis of the mechanism is performed using a hybrid approach that combines elimination and computer algebraic geometry methods. The analysis reveals that the 8-link mechanism has one 2-DOF motion mode and four 1-DOF motion modes. It can switch among three motion modes at four transition configurations and between two motion modes at the remaining four transition configurations. The paper also highlights the geometric characteristics of the mechanism in different motion modes. In contrast to variable-DOF planar mechanisms presented in the literature, the proposed 8-link mechanism has two inactive joints in one of its 1-DOF motion modes. Moreover, both closed-loop 4R kinematic sub-chains of the mechanism must appear as either a pair of parallelograms or a pair of anti-parallelograms in the same motion mode. As a by-product of this research, a method for factoring trigonometric functions in two angles is also proposed. Full article
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2022

Jump to: 2024, 2023, 2021

19 pages, 9275 KiB  
Article
Patient-Specific Stent Fabrication Using a Seven-Degree-of-Freedom Additive Manufacturing System
by John M. Huss, Malachi Lehman and Arthur G. Erdman
Machines 2022, 10(12), 1144; https://doi.org/10.3390/machines10121144 - 01 Dec 2022
Cited by 2 | Viewed by 1468
Abstract
With advances in additive manufacturing technologies, the creation of medical devices which are tailored to the geometry of a patient’s unique anatomy is becoming more feasible. The following paper details the capabilities of a seven-degree-of-freedom fused filament deposition modeling system which enables a [...] Read more.
With advances in additive manufacturing technologies, the creation of medical devices which are tailored to the geometry of a patient’s unique anatomy is becoming more feasible. The following paper details the capabilities of a seven-degree-of-freedom fused filament deposition modeling system which enables a wide variety of user-control over previously restricted parameters, such as nozzle angle, print bed rotation, and print bed tilt. The unique capabilities of this system will be showcased through the production of a patient-specific tracheal stent using three different methods: segmented overmolding, transverse rastering, and longitudinal rastering. The resulting opportunities and time savings demonstrated by the prints will provide a case for greater implementation of seven-degree-of-freedom manufacturing technologies. Full article
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33 pages, 4635 KiB  
Review
Review with Analytical-Numerical Comparison of Contact Force Models for Slotted Joints in Machines
by Matteo Autiero, Mattia Cera, Marco Cirelli, Ettore Pennestrì and Pier Paolo Valentini
Machines 2022, 10(11), 966; https://doi.org/10.3390/machines10110966 - 22 Oct 2022
Cited by 3 | Viewed by 1645
Abstract
The pin-in-the-slot joint is a common element in machines, and the dynamics of joints with clearances is an actively investigated topic. Important applications of such a joint can be found in Geneva mechanisms, robotized gear selectors, centrifugal vibration absorbers (CPVA) and other important [...] Read more.
The pin-in-the-slot joint is a common element in machines, and the dynamics of joints with clearances is an actively investigated topic. Important applications of such a joint can be found in Geneva mechanisms, robotized gear selectors, centrifugal vibration absorbers (CPVA) and other important mechanical devices. The paper will review the main analytical steps required to obtain the equations characterizing the different force contact models. Furthermore, a numerical test bench where such models are introduced for modeling the clearances between the pin and slot is proposed. In this regard, the present study will offer a comparison and discussion of the numerical results obtained with the different force contact models herein reviewed. Full article
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13 pages, 5265 KiB  
Article
Buffering Performance Analysis of an Ostrich-like Leg Based on a Seven-Link Parallel Mechanism
by Daming Nie, Ruilong Du, Jiangren Tian, Pu Zhang, Fangyan Shen, Jason Gu and Yili Fu
Machines 2022, 10(5), 306; https://doi.org/10.3390/machines10050306 - 25 Apr 2022
Cited by 2 | Viewed by 4482
Abstract
As one of the fastest running animals on land, the ostrich’s excellent athletic ability benefits from its unique leg structure. Based on the idea of bionics, this paper intends to obtain a kind of robotic leg structure with a similar buffering capacity to [...] Read more.
As one of the fastest running animals on land, the ostrich’s excellent athletic ability benefits from its unique leg structure. Based on the idea of bionics, this paper intends to obtain a kind of robotic leg structure with a similar buffering capacity to that of the ostrich. For this purpose, the structural characteristics of a seven-link parallel mechanism are analyzed firstly, having some specific features similar to ostrich legs, such as the center of mass (COM) located at the root of the leg, a large folding/unfolding ratio, and so on. Then, the kinematic model of the bionic leg is established, and the energy storage of the flexible parts of the leg is investigated. Finally, an impact experiment of the structure onto the ground is carried out to verify the accuracy of the established kinematic model. This paper systematically reveals the nonlinear law of the elasticity of an ostrich-like leg and provides the buffering performance characteristics of the leg in the process of hitting the ground, based on its elastic properties by the kinematic model and the experiment. Full article
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2021

Jump to: 2024, 2023, 2022

18 pages, 5962 KiB  
Article
Research on the Multi-Robot Cooperative Pursuit Strategy Based on the Zero-Sum Game and Surrounding Points Adjustment
by Gang Chen, Wenqian Xu, Zixing Li, Yuqiang Liu and Xin Liu
Machines 2021, 9(9), 187; https://doi.org/10.3390/machines9090187 - 03 Sep 2021
Cited by 1 | Viewed by 2205
Abstract
Making full use of the cooperation of multi-robots can improve the success rate of apursuit task. Therefore, this paper proposes a multi-robot cooperative pursuit strategy based on the zero-sum game and surrounding points adjustment. First, a mathematical description of the multi-robot pursuit problem [...] Read more.
Making full use of the cooperation of multi-robots can improve the success rate of apursuit task. Therefore, this paper proposes a multi-robot cooperative pursuit strategy based on the zero-sum game and surrounding points adjustment. First, a mathematical description of the multi-robot pursuit problem is constructed, and the zero-sum game model is established considering the cooperation of the pursuit robots and the confrontation between the pursuit robots and the escape robot. By solving the game model, the optimal movement strategies of the pursuit robots and the escape robot are obtained. Then, the position adjustment method of the pursuit robots is studied based on the Hungarian algorithm, and the pursuit robots are controlled to surround the escape robot. Based on this, a multi-robot cooperative pursuit strategy is proposed that divides the pursuit process into two stages: pursuit robot position adjustment and game pursuit. Finally, the correctness and effectiveness of the multi-robot cooperative pursuit strategy are verified with simulation experiments. The multi-robot cooperative pursuit strategy allows the pursuit robots to capture the escape robot successfully without conflicts among the pursuit robots. It can be seen from the documented simulation experiments that the success rate of the pursuit task using the strategy proposed in this paper is 100%. Full article
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26 pages, 8129 KiB  
Article
The Development of an Automated Multi-Spit Lamb Rotisserie Machine for Improved Productivity
by Xun Wei Chia, Poh Kiat Ng, Robert Jeyakumar Nathan, Jian Ai Yeow, Way Soong Lim and Yu Jin Ng
Machines 2021, 9(8), 165; https://doi.org/10.3390/machines9080165 - 11 Aug 2021
Cited by 2 | Viewed by 3653
Abstract
Innovations in food manufacturing support the agenda for sustainable development goal 9 (SDG9) on industry, innovation and infrastructure. Pursuant to this goal, this study aims to develop an automated multi-spit lamb rotisserie machine that potentially improves the lamb-roasting productivity for small and medium [...] Read more.
Innovations in food manufacturing support the agenda for sustainable development goal 9 (SDG9) on industry, innovation and infrastructure. Pursuant to this goal, this study aims to develop an automated multi-spit lamb rotisserie machine that potentially improves the lamb-roasting productivity for small and medium enterprises (SMEs). The conceptualisation involved patents, scholarly literature and product reviews of lamb-roasting devices. The design and analysis are performed using Autodesk Inventor 2019. A scaled-down prototype is developed and tested with (1) roasting output, (2) roasting time and (3) temperature stability tests. The data for test (1) are analysed by comparing the means between control and experimental groups. The data for tests (2) and (3) are analysed using the t-test and Mann–Whitney U test, respectively. Significant differences are observed in tests (1) and (2), with outcomes being in favour of the proposed invention. The prototype cooks 92.27% faster with 700% more meat than a regular lamb roaster. It also cooks at a stable temperature. The cost analysis indicated that this invention could be sold at USD 278 if mass-produced. The design is structurally simple, inexpensive and easy to manufacture, allowing SMEs that rely on traditional spit-based machines to enhance their ability in producing roast lamb. Full article
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