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Full pose measurement system for industrial robots kinematic calibration based on a sensorized spatial linkage mechanism Mech. Mach. Theory (IF 5.2) Pub Date : 2024-04-22 Monica Tiboni, Giovanni Legnani, Roberto Bussola, Diego Tosi
This paper presents a low-cost pose measuring device capable of simultaneously measuring all six coordinates (3 translations and 3 rotations) of a rigid body with respect to a given reference frame. The proposed system consists of a mechanical chain of rigid bodies and two encoders. The mechanism is a spatial four-bar linkage system with a symmetrical Revolute-Spherical-Spherical-Revolute (RSSR) kinematic
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Three-dimensional variable center of mass height biped walking using a new model and nonlinear model predictive control Mech. Mach. Theory (IF 5.2) Pub Date : 2024-04-20 Zhongqu Xie, Yulin Wang, Xiang Luo, Pierluigi Arpenti, Fabio Ruggiero, Bruno Siciliano
This paper presents a trajectory generation algorithm for a three-dimensional (3D) biped robot that can adjust the center of mass (CoM) according to the environment. We adopt a new abstract model that supports vertical motion and rotation. Differing from traditional abstract models, the proposed full centroid dynamics inverted pendulum model fully considers the robot’s movement and rotation. Unlike
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Dynamic stability and efficiency of centrifugal double pendulum vibration absorbers Mech. Mach. Theory (IF 5.2) Pub Date : 2024-04-16 V. Mahé, A. Grolet, A. Renault, H. Mahé, O. Thomas
Centrifugal double pendulum vibration absorbers (CDPVAs) can be used to reduce torsional vibrations of rotating machines. These passive devices are made of several double pendulums oscillating relatively to a rotor. This study extends former works on CDPVAs by accounting for the rotational inertia of the pendulums and providing detailed linear and nonlinear analyses of CDPVA dynamics. First, the eigenmodes
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Analytical model of meshing stiffness, load sharing, and transmission error for internal spur gears with profile modification Mech. Mach. Theory (IF 5.2) Pub Date : 2024-04-13 José I. Pedrero, Miryam B. Sánchez, Miguel Pleguezuelos
The influence of the teeth geometry on the load distribution, transmission error, and meshing stiffness of internal spur gears is very similar to that of external gears. Therefore, the formulation of the models for strength and dynamic calculations for internal and external gears is also similar. However, the internal gears have usually greater values of the contact ratio, frequently above 1.8, even
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Computer aided synthesis method for the configuration of the mechanical arm of face-shovel hydraulic excavator based on contracted graph and open loop kinematic chains Mech. Mach. Theory (IF 5.2) Pub Date : 2024-04-12 Jisong Ding, Xiaoxiong Li, Huafeng Ding, Wenjian Yang
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A method for analyzing wearing uncertainties and enhancing motion transmission smoothness in exoskeletons and its applications for a novel passive knee exoskeleton Mech. Mach. Theory (IF 5.2) Pub Date : 2024-04-11 Yuwei Yang, Zhaotong Li, Jiapeng Yin, Jianchao Gong, Pengyu Chen, Zuyi Zhou
It is suggested that exoskeletons may present challenges in terms of wearability due to unexpected human-machine interaction forces, usually caused by wearing uncertainties such as wearing slips, geometric differences in individual knees, and variable-axis knee movements. Additionally, the forces caused by drastic changes in velocity during exoskeleton locomotion may also be a contributing factor.
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Modeling of flexible shaft for robotics applications Mech. Mach. Theory (IF 5.2) Pub Date : 2024-04-11 Muhammad Usman, Amin Khorasani, Thierry Hubert, Raphaël Furnémont, Bram Vanderborght, Dirk Lefeber, Greet Van de Perre, Tom Verstraten
Reducing moving mass and effective inertia is essential for achieving safe human–robot collaboration. This can be achieved either by employing remote actuation, which moves the mass of actuators away from the moving elements of the robot, or by elastic actuation, which decouples the inertia of the actuator from the inertia of the robot’s link. Flexible shafts, being torsionally compliant slender long
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The cage instability of angular contact ball bearing under high speed conditions Mech. Mach. Theory (IF 5.2) Pub Date : 2024-04-11 Hao Chen, Yuanqing Liu, He Liang, Haibo Zhang, Wenzhong Wang
As a key component of machines, angular contact ball bearings are continuously required to operate at high speeds, cage instability has become a prominent problem, which will seriously affect the performance and service life of bearings. In this study, cage instability is investigated based on the dynamic model considering gross skidding and the interaction between balls and raceways, cage, and guiding
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Configuration design of planetary gear mechanisms of automatic transmissions based on the tree graph and structure constraints Mech. Mach. Theory (IF 5.2) Pub Date : 2024-04-10 Wenjian Yang, Yongtao Li, Huafeng Ding
The topological synthesis of planetary gear trains (PGTs) is an important basis for designing mechanisms of automatic transmissions (ATs). However, the existing methods for topological synthesis of PGTs mainly focus on non-fractionated 1-degree-of-freedom (DOF) PGTs, with little attention given to the PGTs with fractionated configurations or multiple DOFs. In addition, most existing methods are dedicated
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Anti-disturbance performance analysis and the innovative design of the FAST fine-tuning platform Mech. Mach. Theory (IF 5.2) Pub Date : 2024-04-09 Jinhao Duan, Hanqing Liu, Zhufeng Shao, Rui Yao, Zhaokun Zhang, Stéphane Caro
In order to further increase the observation range and sensitivity of the Five-hundred-meter Aperture Spherical Telescope (FAST), an innovative design of the cable-driven fine-tuning platform (CDFP) is required to replace the existing bulky rigid mechanism to increase rotation capability and reduce weight for more powerful receivers. A key issue is to ensure its stability and anti-disturbance ability
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Dynamic modeling and validation of a hybrid-driven continuum robot with antagonistic mechanisms Mech. Mach. Theory (IF 5.2) Pub Date : 2024-04-09 Jun Yang, Edward Harsono, Haoyong Yu
To satisfy the actual needs of different tasks, hybrid-driven continuum robots need to effectively cope with rapid internal dynamic changes, relatively fast motion speeds, and enhanced flexibility in motions. This fact forces us to seek solutions from the perspective of the dynamics of continuum robots. However, the integration of multiple actuations introduces complexity to dynamic modeling. Therefore
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Design and simulation study of novel reaction wheels with adjustable inertia for enhanced attitude control Mech. Mach. Theory (IF 5.2) Pub Date : 2024-04-08 Sajjad Keshtkar, Hirohisa Kojima
This study introduces a novel approach for improving the performance of reaction wheels by dynamically altering their moment of inertia. To achieve this, several innovative mechanisms based on adjustable mass distribution, wheels with variable geometry, and systems with multiple wheels are proposed. A generalized mathematical model is developed, which employs the radius of gyration as the variable
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A study of the instantaneous centers of velocity for 1-dof and 2-dof planar linkages Mech. Mach. Theory (IF 5.2) Pub Date : 2024-04-04 David E. Foster, Gordon R. Pennock
This paper presents a detailed study of the instantaneous centers of velocity (henceforth referred to as instant centers) and the lines containing the instant centers for one-degree-of-freedom (1-dof) and two-degree-of-freedom (2-dof) planar linkages with up to 11 links. The focus is on graphical methods to locate secondary instant centers (that is, instant centers which are unknown from inspection
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Influence of eccentricity error on the orbit of a two-stage double-helical compound planetary gear train with different mesh phasing configurations Mech. Mach. Theory (IF 5.2) Pub Date : 2024-03-28 Guanghe Huo, Miguel Iglesias-Santamaria, Xiang Zhang, Javier Sanchez-Espiga, Enrique Caso-Fernandez, Yinghou Jiao, Fernando Viadero-Rueda
The eccentricity error is an unavoidable error during the manufacturing and mounting process and has a significant influence on the response of gear systems, especially for planetary gear train. First, based on the most basic quasi-static model, pressure angle, contact ratio and meshing stiffness are considered to be the time-varying parameters due to the eccentricity error. Then, a new quasi-static
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Computing complete solution sets for approximate four-bar path synthesis Mech. Mach. Theory (IF 5.2) Pub Date : 2024-03-27 Caroline Hills, Aravind Baskar, Mark Plecnik, Jonathan D. Hauenstein
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Some five dimensional persistent submanifolds of the Study quadric Mech. Mach. Theory (IF 5.2) Pub Date : 2024-03-23 J.M. Selig, V. Di Paola
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The inverse kinematics of lobster arms Mech. Mach. Theory (IF 5.2) Pub Date : 2024-03-21 Federico Thomas, Josep M. Porta
The roots of the closure polynomial associated with a given mechanism determine its assembly modes. In the case of 6R closed-loop mechanisms, these polynomials are usually expressed in the half-angle tangent of one of its joints. In this paper, we derive closure polynomials of 6R robots in terms of distances, not angles. The use of a distance-based formulation provides, in general, a fundamental advantage
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A novel stiffness-controllable joint using antagonistic actuation principles Mech. Mach. Theory (IF 5.2) Pub Date : 2024-03-19 Wenlong Gaozhang, Yue Li, Jialei Shi, Yaxi Wang, Agostino Stilli, Helge Wurdemann
The inherent safety of collaborative robots is essential for enhancing human–robot interaction. The primary challenge in creating soft components for these robots is achieving sufficient force and stiffness. This paper presents a joint design for collaborative robots that addresses this challenge by incorporating an antagonistic actuation principle, allowing for adjustable stiffness. The novelty of
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High-order kinematics of uniform flexures Mech. Mach. Theory (IF 5.2) Pub Date : 2024-03-16 M. Verotti
In the last decades, many efforts have been made to analyze and model small and large deflections of flexures, considering complex load cases and different solution techniques. However, few investigations focused on the kinematic aspects related to the deflection analysis of the flexible elements, and limited the study to the second-order kinematics. In this paper, an analytical formulation based on
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A single-input state-switching building block harnessing internal instabilities Mech. Mach. Theory (IF 5.2) Pub Date : 2024-03-16 Malte A. ten Wolde, Davood Farhadi
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An exact system of generation for face-milled hypoid gears with uniform depth taper: Application to hypoid gear drives with high gear ratio Mech. Mach. Theory (IF 5.2) Pub Date : 2024-03-15 Ignacio Gonzalez-Perez, Alfonso Fuentes-Aznar
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Instantaneous Kinematics and Singularity Analysis of Spatial Multi-DOF Mechanisms Based on the Locations of the Instantaneous Screw Axes Mech. Mach. Theory (IF 5.2) Pub Date : 2024-03-15 Raffaele Di Gregorio
Multi-degree-of-freedom (multi-DOF) mechanisms generate single-DOF mechanisms by locking all their generalized coordinates but one. Here, the superposition principle is used to state a relationship between spatial multi-DOF mechanisms’ instantaneous kinematics (IK) and the IK of the single-DOF mechanisms they generate. Firstly, the relationship between the instantaneous screw axes (ISAs) of a multi-DOF
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Analytical determination of back-side contact force for paralleled beveloid gear Mech. Mach. Theory (IF 5.2) Pub Date : 2024-03-14 Feihong Zhu, Chaosheng Song, Luca Bonaiti, Carlo Gorla
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A unified analytical disk cam profile generation methodology using the Instantaneous Center of Rotation for educational purpose Mech. Mach. Theory (IF 5.2) Pub Date : 2024-03-12 Xabier Iriarte, Julen Bacaicoa, Aitor Plaza, Jokin Aginaga
Cam design is a fundamental part of the Mechanism and Machine Theory (MMT) and is included in the vast majority of MMT books. Cam profile design is usually determined with graphical and analytical methods. Graphical methods are didactically very successful to introduce the theory of cam profile generation in a simple way. In turn, analytical methods allow computer implementations of cam profile generation
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Reviewer acknowledgments and awards: Recognition awards for distinction of reviewing in 2023 Mech. Mach. Theory (IF 5.2) Pub Date : 2024-03-12 Paulo Flores
In 2023, members of the journal's Editorial Board and many independent reviewers contributed their time and expertise in reviewing manuscripts. This process greatly benefits our editors, contributing authors, and ultimately our readers. In fact, the high standard and reputation of the journal is strongly shaped by the expert knowledge, generous time contribution, and commitment to mechanism and machine
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Compliant variable negative to zero to positive stiffness twisting elements Mech. Mach. Theory (IF 5.2) Pub Date : 2024-03-07 Ali Amoozandeh Nobaveh, Just L. Herder, Giuseppe Radaelli
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An efficient solver for the inverse kinematics of cable-driven manipulators with pure rolling joints using a geometric iterative approach Mech. Mach. Theory (IF 5.2) Pub Date : 2024-03-05 Haotian Yang, Chongkun Xia, Xueqian Wang, Wenfu Xu, Bin Liang
The inverse kinematics (IK) problem of cable-driven manipulators with pure rolling joints (CDM-PRJs) presents unique challenges due to the equal angle constraints and strict joint limits. These factors render existing IK solvers ineffective or result in substantial degradation of their performance. To address these challenges, we propose a three-phase geometric iterative method to efficiently solve
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Kinematic jerk and jounce for multibody dynamics with joint constraints Mech. Mach. Theory (IF 5.2) Pub Date : 2024-03-01 H.J. Sommer III
Planar and spatial joint constraint equations for jerk and jounce were derived for multibody dynamics. Exemplar derivations are provided. Results from kinematically driven numerical simulations of these new equations were compared to explicit geometric solutions for planar four-bar and inverted slider-crank mechanisms as well as spatial revolute-spherical-universal-revolute and revolute-spherical-prismatic-universal
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Kinematics and workspace analysis of a 3-CR(Pa)(Pa)R parallel mechanism with an orthogonal layout Mech. Mach. Theory (IF 5.2) Pub Date : 2024-02-29 Shuai Zhang, Wei Li, Songlin Zhou, Jorge Angeles, Weixing Chen, Feng Gao, Weizhong Guo
The authors report on the kinematics and workspace analysis of a six-dof 3-R(Pa)(Pa)R parallel mechanism (PM) with an orthogonal layout, which is found to bear various advantageous features. A compact forward-kinematics model is established, leading to a linear univariate characteristic polynomial, significantly reducing the computational cost. Moreover, the velocity-level kinematics indicates that
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Kinematically redundant (6+2)-dof HEXA robot for singularity avoidance and workspace augmentation Mech. Mach. Theory (IF 5.2) Pub Date : 2024-02-28 Joshua Flight, Clément Gosselin
This paper introduces a novel (6+2)-degree-of-freedom (dof) kinematically redundant parallel robot. The proposed architecture is based on the 6-dof HEXA parallel robot. The paper applies methodologies for avoiding type II singularities using kinematic redundancy that were originally proposed for robots with prismatic actuators to a new architecture with revolute actuators. The singularities of the
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Face gear drives: Nominal contact stress calculation for flank load carrying capacity evaluation Mech. Mach. Theory (IF 5.2) Pub Date : 2024-02-26 Jonas-Frederick Hochrein, Michael Otto, Karsten Stahl
Face gear drives are angular gear units in which an involute pinion meshes with a face gear wheel. Spur and helical face gear drives are possible with or without center offset. Face gear drives can be manufactured on conventional gear cutting machines. Furthermore, the pinion is free to move axially and such displacements have no effect on the contact pattern. This makes them a promising gearing for
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A numerical continuation approach using monodromy to solve the forward kinematics of cable-driven parallel robots with sagging cables Mech. Mach. Theory (IF 5.2) Pub Date : 2024-02-21 Aravind Baskar, Mark Plecnik, Jonathan D. Hauenstein, Charles W. Wampler
Designing and analyzing large cable-driven parallel robots (CDPRs) for precision tasks can be challenging, as the position kinematics are governed by kineto-statics and cable sag equations. Our aim is to find all equilibria for a given set of unstrained cable lengths using numerical continuation techniques. The Irvine sagging cable model contains both non-algebraic and multi-valued functions. The former
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Hexad robot: A 6-dof parallel PnP robot to accommodate antagonistic rotational capability and structural complexity Mech. Mach. Theory (IF 5.2) Pub Date : 2024-02-21 Guanglei Wu, Bin Niu
This paper proposed a new structure of full-mobility parallel robot, which combined the advantages of high-rotational capabilities and structural simplification, for high-speed operations of material handling. The proposed robot structure integrates lightweight and simple linkages with a relatively complex (i.e., compared to the single platform with limited rotational capability) articulated mechanism
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Design considerations and workspace computation of 2-X and 2-R planar cable-driven tensegrity-inspired manipulators Mech. Mach. Theory (IF 5.2) Pub Date : 2024-02-19 Vimalesh Muralidharan, Philippe Wenger, Christine Chevallereau
This study considers two-degree-of-freedom planar tensegrity-inspired manipulators composed of anti-parallelogram (X) and revolute (R) joints containing springs and actuated remotely by four cables. The goal is to design the constituent elements of these manipulators while they carry a given payload in the presence of gravity. While this is a classical problem in serial and parallel manipulators with
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The direct vector approach to the position analysis of Assur dyads Mech. Mach. Theory (IF 5.2) Pub Date : 2024-02-16 Kostiantyn Khoroshev, Kyryl Duchenko, Serhii Kykot
A modular approach to the kinematics of planar linkages is based on a structural analysis of the mechanisms. Kinematic chains that can be synthesized according to Assur principle are well classified by their structure. Such a classification allows the development of general methods of the kinematics of subchains that can be algorithmized and used for computer-aided design. The paper introduces a new
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A family of generalized single-loop RCM parallel mechanisms: structure synthesis, kinematic model, and case study Mech. Mach. Theory (IF 5.2) Pub Date : 2024-02-13 Luquan Li, Dan Zhang, Chunxu Tian
In this paper, a novel family of generalized single-loop remote center of motion (RCM) parallel mechanisms (PMs) based on a spherical surface geometric model is proposed. The underlying principles behind generating RCM motion are intuitively revealed through geometry. The spherical surface geometric models are first constructed through the application of the midperpendicular theorem of chords by utilizing
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Shape optimization of buckling-based deployable stiff structures Mech. Mach. Theory (IF 5.2) Pub Date : 2024-02-08 Hoo Min Lee, Gil Ho Yoon, Jonas Engqvist, Matti Ristinmaa, Mathias Wallin
This study considers deployable structures and presents a novel optimization method that aims to improve the stiffness at the fully deployed state. The considered structures consist of curved beams that deploy through buckling when rotated. The optimization aims to maximize the structural tangent stiffness by modifying the shape of the beam elements. To accurately predict the deformation, Finite Element
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Design optimization and validation of compliant bidirectional constant force mechanisms Mech. Mach. Theory (IF 5.2) Pub Date : 2024-02-07 Jing Li, Tanzeel Ur Rehman, Zeeshan Qaiser, Shane Johnson
Mechanical vibration is a valuable energy source, ideal for storing energy from cyclic loads like human activities, ocean waves, and automotive vibrations. Compared to the typically designed unidirectional compliant Constant Force Mechanisms (CFMs), Bidirectional Compliant Constant Force Mechanisms (Bi-CFMs) improve energy storage efficiency in reversed cyclic loads. Two types of Bi-CFMs, Bidirectional
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Singularity distance computations for 3-RPR manipulators using extrinsic metrics Mech. Mach. Theory (IF 5.2) Pub Date : 2024-02-07 Aditya Kapilavai, Georg Nawratil
It is well-known that parallel manipulators are prone to singularities. However, there is still a lack of distance evaluation functions, referred to as metrics, for computing the distance between two 3-RPR configurations. The proposed extrinsic metrics take the combinatorial structure of the manipulator into account as well as different design options. Utilizing these extrinsic metrics, we formulate
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Nonlinear strain energy formulation of spatially deflected strip flexures Mech. Mach. Theory (IF 5.2) Pub Date : 2024-02-06 Ruiyu Bai, Nan Yang, Bo Li, Guimin Chen
Modeling spatial deflections of strip flexures in compliant mechanisms has been one of the most challenging problems due to the nonlinear coupling effects between bending, torsion and stretching. Energy-based approaches can mitigate the modeling complexity by treating a compliant mechanism in its entirety and eliminating the analysis of load equilibriums between the adjacent elements. To leverage energy-based
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Fault-tolerant gait design for quadruped robots with two locked legs using the GF set theory Mech. Mach. Theory (IF 5.2) Pub Date : 2024-02-03 Zhijun Chen, Qingxing Xi, Chenkun Qi, Xianbao Chen, Yue Gao, Feng Gao
Fault-tolerant gaits can give legged robots the ability to walk under fault conditions, and hence prolong the service life. However, for quadruped robots with two locked legs, fault-tolerant gaits can be rarely found. This paper proposes a novel fault-tolerant gait for quadruped robots with two locked legs using the G set theory. First, a quadruped robot and eight stages of its fault-free static gait
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A novel analytical method for meshing characteristics of spiral bevel gears considering slice coupling Mech. Mach. Theory (IF 5.2) Pub Date : 2024-02-03 Wenkang Huang, Zhanwei Li, Hui Ma, Jiazan Zhu, Zimeng Liu, Hansheng Song, Haodong Hu, Xin Li, Yang Yang, Zhike Peng
The meshing characteristics (MCs) including time-varying meshing stiffness (TVMS), loaded transmission error (LTE) and contact stress are the key indexes of spiral bevel gears (SBGs). Traditional analytical methods for SBGs have some limitations in MCs calculation, including the utilization of finite element (FE) method-based correction coefficients to compute tooth compliance and the oversight of
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Using instantaneous invariants of the curvature theory in motion generation synthesis of 4R mechanisms with higher-order coupler point kinematics Mech. Mach. Theory (IF 5.2) Pub Date : 2024-02-03 N, a, d, i, m, , D, i, a, b
This paper aims at exploiting the unique characteristics of instantaneous invariants and pole locations in synthesizing motion generation four bar (4R) planar mechanisms with higher-order coupler point kinematics (i.e. specifying coupler point velocity and/or acceleration in addition to its position and coupler orientation). The proposed methodology targets to ease the complexity of such design problems
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Modular Modeling Methodology applied to kinematically redundant parallel mechanisms Mech. Mach. Theory (IF 5.2) Pub Date : 2024-01-31 T.A. Hess-Coelho, É.L. de Oliveira, R.M.M. Orsino, F. Malvezzi
The Modular Modeling Methodology (MMM) is a general approach, applicable for holonomic or nonholonomic multibody systems, which allows the integrated use of libraries of already available mathematical models along with general-purpose computational tools. This paper extends the application of the Modular Modeling Methodology to kinematically redundant parallel mechanisms and identifies its relevant
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SuRFR: A fast recursive simulator for soft manipulators with discrete joints on SE(3) Mech. Mach. Theory (IF 5.2) Pub Date : 2024-01-27 Hossain Samei, Robin Chhabra
We develop a fast, recursive, and parameterization-free formulation for the dynamics of soft robots. Such systems are modelled as multi-body systems, composed of rigid and flexible bodies connected with discrete joints. We couple the recursive Newton–Euler equation for rigid bodies and the Partial Differential Equations (PDEs) on the Special Euclidean group SE(3) modelling dynamic Cosserat rods to
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Henry Léauté: The forgotten kinematician and discoverer of the cubic of stationary curvature equation Mech. Mach. Theory (IF 5.2) Pub Date : 2024-01-29 V.R. Shanmukhasundaram, M. Cirelli, E. Pennestrì
Henry Léauté (1847–1916) was a French kinematician who taught at the École polytechnique. In 1878, Léauté derived the cubic of stationary curvature (CSC) equation in its modern form which is widely applied as a tool for synthesizing path generator mechanisms. The deduction of CSC equation by Léauté is based on an earlier work from the French school due to A. Mannheim in 1872. According to historical
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Disturbance torque observer-based variable impedance control for compliant stair-descending of transformable wheel mechanism Mech. Mach. Theory (IF 5.2) Pub Date : 2024-01-25 Kwan Yeong Yoo, Sanggyun Kim, Inha Park, Hyeongyu Yoon, Hwa Soo Kim, TaeWon Seo
This study presents a disturbance torque observer-based variable impedance control method to mitigate the disturbance force acting on the 2-degree-of-freedom (DOF) transformable wheel mechanism. Compared to the previous study, the numerical solution of forward kinematic problem is calculated over the entire operating ranges of joint angles and the viability of dynamic model for the proposed transformable
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Corrigendum to “A tyre-rim interaction digital twin for biaxial loading conditions” [Mechanism and Machine Theory; 191, January 2024, 105491] Mech. Mach. Theory (IF 5.2) Pub Date : 2024-01-22 Simone Venturini, Elvio Bonisoli, Calo Rosso, Mauro Velardocchia
Abstract not available
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Mechanism motion scheme design and dynamic analysis of biomimetic jellyfish adapt to different application Mech. Mach. Theory (IF 5.2) Pub Date : 2024-01-23 Yanlin Li, Lifang Qiu, Yakun He, Shenyuan Dai
In order to design a motion scheme that can achieve higher motion performance according to different application environment, a dynamic model of biomimetic jellyfish based on waterbomb was established. The influence of dynamic parameters on the motion performance was analyzed for two types of motion modes including Prolate type jellyfish and Oblate type jellyfish. Two motion schemes were designed based
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Parametric analysis of tooth surface characteristics of flexspline in harmonic reducer after hobbing Mech. Mach. Theory (IF 5.2) Pub Date : 2024-01-16 Chaosheng Song, Xinzi Li, Caichao Zhu, Xuesong Du
The accurate prediction of tooth surface morphology for the flexspline in harmonic reducers after hobbing is a crucial technology for achieving high-precision harmonic gearing. This study investigates the impact of process parameters on the tooth surface characteristics of the flexspline. Two models were established to study the formation of tooth surfaces using both continuous cutting with a hypothetical
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Available wrench set robustness under hybrid joint-space control to uncertain wrench for a cable-driven parallel robot Mech. Mach. Theory (IF 5.2) Pub Date : 2024-01-08 Guangyao Sun, Zhen Liu, Haibo Gao, Cong Sun, Zhiwei Qin, Zongquan Deng
For a overconstrained cable-driven parallel robot (CDPR), the number of cables is more than the number of the moving platform degrees of freedom. Therefore, a hybrid joint-space control method is used, where as many cables as the moving platform degrees of freedom are kinematically controlled, and the redundant ones are tension controlled. However, the selection of which cables to tension control is
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Elastostatic analysis of a module-based shape morphing snake-like robot Mech. Mach. Theory (IF 5.2) Pub Date : 2024-01-09 Alessandro Cammarata, Pietro Davide Maddio, Rosario Sinatra, Yingzhong Tian, Yinjun Zhao, Fengfeng Xi
This paper describes the stiffness analysis of a module-based shape morphing snake-like robot. Snake-like robots have the characteristic of adapting to unstructured environments by exploiting their ability to reconfigure their body’s shape. However, the excellent mobility contrasts with the ability to transmit high loads, precluding its application in manufacturing operations. This article presents
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A multibody-dynamics based method for the estimation of wear evolution in the revolute joints of mechanisms that considers link flexibility Mech. Mach. Theory (IF 5.2) Pub Date : 2024-01-06 M. López-Lombardero, J. Cuadrado, M. Cabello, F. Martinez, D. Dopico, A. López-Varela
Mechanical systems are subject to multiple imperfections due to manufacturing and assembly defects, or to wear. Wear critical, because it involves degradation of the joints, increased clearances and, hence, increased contact forces, fatigue, etc. Although the computational estimation of wear evolution and its effect on the system can be difficult, multibody dynamics simulations have proved to be very
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Design and optimization of a novel sagittal-plane knee exoskeleton with remote-center-of-motion mechanism Mech. Mach. Theory (IF 5.2) Pub Date : 2024-01-05 Hongyan Tang, Yanfei Li, James W. Zhang, Dan Zhang, Hongliu Yu
Powered exoskeleton is a wearable robot that can provide power-assisted motion for the human body. One of the challenges in the exoskeleton research is how to improve its kinematic synergy. In this paper, a novel knee exoskeleton robot is designed to improve the kinematic synergy between the exoskeleton and the human body. The novel exoskeleton adopts the sagittal-plane layout to reduce the bias moment
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Analytical and numerical investigation of second-order infinitesimal mechanism in rigid origami Mech. Mach. Theory (IF 5.2) Pub Date : 2024-01-04 Kentaro Hayakawa, Tomotaka Ohba, Makoto Ohsaki
This study investigates second-order infinitesimal mechanisms and bifurcation paths of rigid origamis with multiple-degree-of-freedom mechanisms. A truss model, consisting of pin-connected rigid bars, is employed for the infinitesimal mechanism analysis. The conditions for the existence of a second-order infinitesimal mechanism are analytically solved to investigate the combinations of the infinitesimal
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Time-varying mesh stiffness calculation of spiral bevel gear with spalling defect Mech. Mach. Theory (IF 5.2) Pub Date : 2023-12-27 Zhanwei Li, Juntao Zhang, Hansheng Song, Rupeng Zhu, Hui Ma
Spiral bevel gears often operate at high speeds and under heavy loads, which can easily lead to the occurrence of spalling faults on the tooth surfaces, particularly in cases of inadequate lubrication. In this study, we introduce an efficient and accurate numerical calculation method to determine the time-varying meshing stiffness (TVMS) of a spiral bevel gear pair with actual spalling faults, taking
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Concept design of a monolithic compliant series-elastic actuator with integrated position and two-level force sensing Mech. Mach. Theory (IF 5.2) Pub Date : 2023-12-28 Zekui Lyu, Yuning Cao, Michael Yu Wang, Qingsong Xu
Safe physical interaction is significant for the protection of the operated target during delicate micromanipulation tasks. This paper proposes the concept design of a series-elastic actuator mainly constructed by a fully compliant mechanism. It can reduce the transient contact force when the tip touches an object and monitor the interaction force in real time for safe handling. The rear end of the
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Sarrus-inspired deployable polyhedral mechanisms Mech. Mach. Theory (IF 5.2) Pub Date : 2023-12-22 Yuanqing Gu, Xiao Zhang, Guowu Wei, Yan Chen
Deployable polyhedral mechanisms (DPMs) have witnessed flourishing growth in recent years because of their potential applications in robotics, space exploration, structure engineering, and so forth. This paper firstly presents the construction, mobility and kinematics of a family of Sarrus-inspired deployable polyhedral mechanisms. By carrying out expansion operation and implanting Sarrus linkages