Mechanism and Machine Theory最新文献_第10页

Design and analysis of a portable wrist rehabilitation instrument based on Bricard linkage 基于Bricard连杆的便携式腕部康复仪的设计与分析

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-12-01 Epub Date: 2025-10-08 DOI: 10.1016/j.mechmachtheory.2025.106253

Shun Yao , Jinyi Lv , Zhuoni Liu , Yuqiao Jiang , Jiangming Kan

In this paper, a portable wrist rehabilitation instrument based on the Bricard linkage is presented. The instrument functions through the spatial tumbling of the Bricard linkage. The movement has similarities with wrist kinematics and is designed to guide wrist rehabilitation. First, the mechanical scheme of the instrument is presented. The wrist kinematics is analyzed, which are flexion & extension, ulnar & radial deviation. Second, for the reason that the movements of the Bricard linkage are similar to that of the Schatz linkage, the kinematic of the instrument is analyzed through the Schatz linkage. Third, the energy consumption of the instrument is calculated and a corresponding wrist rehabilitation exercise is choreographed. Finally, a prototype is manufactured, and a series of experiments are carried out. The results validate that the wrists could be guided by the instrument. The wrists could be fully exercised, and the efficiency of the rehabilitation would be evaluated by the energy consumption in the wrist exercise.

本文提出了一种基于Bricard连杆的便携式腕部康复仪。该仪器通过布里卡连杆的空间翻滚发挥作用。该运动与手腕运动有相似之处，旨在指导手腕康复。首先，给出了仪器的机械结构方案。分析了腕部屈伸、尺桡偏移的运动学特征。其次，由于布里卡德连杆机构的运动与沙茨连杆机构相似，因此通过沙茨连杆机构对仪器的运动学进行了分析。第三，计算仪器的能量消耗，并编排相应的手腕康复运动。最后，制作了样机，并进行了一系列实验。结果表明，该仪器可以实现腕关节的引导。可以充分锻炼腕关节，通过腕关节运动的能量消耗来评价康复效果。

引用次数: 0

Research on a novel multiple cable-nets swing capture mechanism and its space gripper design 一种新型多索网摆动捕获机构及其空间夹持器设计研究

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-12-01 Epub Date: 2025-10-18 DOI: 10.1016/j.mechmachtheory.2025.106264

Yuan Jiang , Yongsheng Zhao , Yi Luo , Qianqian Gu , Xiaohan Liu , Meng Han , Bo Han

Space capture is a key technology for deep space exploration, serving missions such as orbital debris removal and asteroid sampling. Target objects are typically non-cooperative and operate in environments devoid of gravity and fluid resistance, posing significant challenges to effective capture. Cables, known for their compliance and excellent mechanical properties, have been used in space capture tasks. However, few studies have achieved both reliable control and the use of cables as end-effectors. To address this gap, this paper proposes a novel mechanism—the multiple cable-nets swing capture mechanism (MCNS-CM)—which enables compliant capture of targets by synchronously swinging multiple intersecting cable-nets to narrow the capture space. MCNS-CM employs cables as the end-effector structure, offering low-impact, high-compliance, and self-adaptive contact behavior. The mathematical principles, kinematic and mechanical models of MCNS-CM are presented. Two proof-of-concept prototypes were fabricated, and a series of capture experiments were conducted, demonstrating the feasibility of MCNS-CM in space capture and related applications. This work provides new insights and a theoretical foundation for the advancement of future space capture technologies.

空间捕获是深空探测的一项关键技术，服务于轨道碎片清除和小行星采样等任务。目标物体通常是非合作的，并且在没有重力和流体阻力的环境中运行，这对有效捕获构成了重大挑战。电缆以其顺应性和优异的机械性能而闻名，已用于空间捕获任务。然而，很少有研究既能实现可靠的控制，又能使用电缆作为末端执行器。为了解决这一差距，本文提出了一种新的机制——多缆网摆动捕获机制（MCNS-CM），该机制通过同步摆动多个相交的缆网来缩小捕获空间，从而实现目标的顺从捕获。MCNS-CM采用电缆作为末端执行器结构，提供低冲击，高顺应性和自适应接触行为。介绍了MCNS-CM的数学原理、运动学模型和力学模型。制作了两个概念验证原型，并进行了一系列捕获实验，证明了MCNS-CM在空间捕获和相关应用中的可行性。这项工作为未来空间捕获技术的发展提供了新的见解和理论基础。

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引用次数: 0

Multi-configuration recognition of a 3-RSR parallel mechanism with zero-torsion characteristics based on screw algebra and high-order kinematics 基于螺旋代数和高阶运动学的零扭力3-RSR并联机构多构型识别

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-12-01 Epub Date: 2025-10-18 DOI: 10.1016/j.mechmachtheory.2025.106249

Haolin Zhang, Lizi Deng, Zhao Tang, Jian S. Dai

In this paper, a comprehensive high-order kinematic analysis of a geometrically symmetric 3-RSR parallel mechanism is conducted based on screw algebra. A screw-based modeling framework is first established to represent the pose and evaluate the mobility under zero-torsion characteristics, revealing the mechanism's intrinsic 2R1T motion pattern. The bifurcation configurations of the 3-RSR mechanism under singularity are then identified, deriving five distinct motion modes: decoupled limb-swinging, parallel translation, two interfering rotational modes, and axis rotation. Eleven bifurcated motion branches are subsequently derived through high-order velocity constraints and symmetry extension. In particular, a complete symmetry-based configuration space is constructed for the first time, which enables systematic recognition and classification of multimodal motion. Moreover, the feasibility of connectivity among motion branches is verified through constraint screw evolution. These findings not only deepen the understanding of singularity-induced bifurcations in reconfigurable parallel mechanisms, but also establish the constraint principles that govern configuration transitions of reconfigurable parallel mechanisms under singular configurations.

本文基于螺旋代数对几何对称3-RSR并联机构进行了全面的高阶运动学分析。首先建立了基于螺旋的姿态建模框架，并对机构零扭转特性下的机动性进行了评估，揭示了机构固有的2R1T运动模式。在此基础上，对3-RSR机构在奇异点下的分岔构型进行了辨识，推导出解耦摆动臂、并联平移、双干涉旋转和轴向旋转五种不同的运动模式。通过高阶速度约束和对称扩展导出了11个运动分支。特别是首次构建了一个完整的基于对称的构型空间，实现了对多模态运动的系统识别和分类。通过约束螺杆演化验证了运动分支间连通性的可行性。这些发现不仅加深了对可重构并联机构奇点分岔的认识，而且建立了奇异构型下可重构并联机构构型转移的约束原则。

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引用次数: 0

Design and analysis of a new parallel mechanism with foldable moving platforms—coupled with its conceptual design in multi-pose tracking of PV modules 一种新型可折叠移动平台并联机构的设计与分析——结合光伏组件多姿态跟踪的概念设计

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-12-01 Epub Date: 2025-10-17 DOI: 10.1016/j.mechmachtheory.2025.106261

Huiping Shen, Xingyu She, Zhongqiu Du, Pengda Ye, Ju Li

In the work, a new concept of parallel mechanism(PM) with two foldable moving platforms, i.e., foldable PM, is proposed. A 4-DOF 2T1R foldable PM consists of two sub-PMs connected by one shared hybrid limb is designed and analyzed, each sub-PM of which possess 2T1R output motion. Only through control of the actuated joints of the foldable PM, without changing topology of the foldable PM itself, its two sub-moving platforms can reach respective 2T1R motion output. First, topological characteristics of the foldable PM are analyzed, including position and orientation characteristics (POC), degrees of freedom (DOF) etc. Second, symbolic forward and inverse position solutions, workspace and singular analysis are performed. Third, the dynamic equations and actuated force curves are established through the virtual work principle. Fourth, dimensional optimization is conducted with the maximum attitude angle as the objective function. Finally, the conceptual design of the foldable PM used for multi-pose tracking of photovoltaic (PV) modules for efficient energy absorption is elaborated. This work expands the concept, design, and application scope of reconfigurable or multi-mode PMs.

本文提出了一种具有两个可折叠移动平台的并联机构的新概念，即可折叠并联机构。设计并分析了一种4自由度2T1R可折叠永磁机构，该机构由两个子永磁机构组成，每个子永磁机构具有2T1R输出运动。仅通过控制可折叠永磁机构的驱动关节，在不改变可折叠永磁机构本身拓扑结构的情况下，其两个子运动平台即可达到各自的2T1R运动输出。首先，分析了可折叠PM的拓扑特性，包括位姿特性（POC）、自由度（DOF）等。其次，进行了符号正、逆位置解、工作空间和奇异性分析。第三，利用虚功原理建立了动力方程和驱动力曲线。第四，以最大姿态角为目标函数进行量纲优化。最后，阐述了用于光伏组件多姿态跟踪的可折叠PM的概念设计，以实现高效的能量吸收。这项工作扩展了可重构或多模式pm的概念、设计和应用范围。

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引用次数: 0

Dynamic responses and non-probabilistic reliability analysis of flexible manipulator considering clearance joint and multiple uncertainties 考虑间隙关节和多重不确定性的柔性机械臂动态响应及非概率可靠性分析

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-12-01 Epub Date: 2025-10-04 DOI: 10.1016/j.mechmachtheory.2025.106235

Zhengfeng Bai , Yuxin Niu , Lewen Cui

Joint clearances and uncertain parameters in the space manipulator are inevitable, which adversely affect the motion accuracy and reliability of the manipulator system. In this paper, dynamic model and a novel reliability calculation method are presented to analyze the performance of the flexible manipulator considering clearance joint and multiple uncertainties. Firstly, the nonlinear contact-impact model in the clearance joint is established. Based on the Euler-Bernoulli beam theory, the deformation of the flexible arm is modeled using assumed-mode method. Furthermore, dynamics equations of two-link manipulator are established by utilizing the Lagrange method. The uncertainties are defined as interval parameters, and a Chebyshev-based interval method is proposed to calculate the dynamic response bound of flexible manipulator system with high-dimensional uncertainties. To predict the motion reliability, a limit state function and an innovative non-probabilistic reliability index are proposed. Finally, numerical simulations are implemented to verify the effectiveness of the proposed approaches. Results show that the proposed methods can effectively obtain accurate dynamic responses and reliability prediction, which provide basis for performance evaluation and motion control of manipulator systems.

空间机械臂中不可避免地存在关节间隙和不确定参数，对机械臂系统的运动精度和可靠性产生不利影响。本文建立了考虑间隙关节和多重不确定因素的柔性机械臂动力学模型，并提出了一种新的可靠性计算方法。首先，建立了间隙关节的非线性接触-冲击模型；基于欧拉-伯努利梁理论，采用假设模态方法对柔性臂的变形进行了建模。在此基础上，利用拉格朗日方法建立了双连杆机械手的动力学方程。将不确定性定义为区间参数，提出了一种基于chebyhev的区间方法来计算具有高维不确定性的柔性机械臂系统的动态响应界。为了预测运动可靠性，提出了极限状态函数和一种创新的非概率可靠性指标。最后，通过数值仿真验证了所提方法的有效性。结果表明，该方法能有效地获得准确的动态响应和可靠性预测，为机械臂系统的性能评估和运动控制提供依据。

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引用次数: 0

Kinetostatics and Particle-Swarm Optimization of vehicle-mounted underactuated metamorphic loading manipulators 车载欠驱动变形装载机的动静力学与粒子群优化

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-12-01 Epub Date: 2025-10-16 DOI: 10.1016/j.mechmachtheory.2025.106254

Nan Mao , Junpeng Chen , Guanglu Jia , Emmanouil Spyrakos-Papastavridis , Jian S. Dai

Fixed degree-of-freedom (DoF) loading mechanisms often suffer from excessive actuators, complex control, and limited adaptability to dynamic tasks. This study proposes an innovative mechanism of underactuated metamorphic loading manipulators (UMLM), integrating a metamorphic arm with a passively adaptive gripper. The metamorphic arm exploits geometric constraints, enabling the topology reconfiguration and flexible motion trajectories without additional actuators. The adaptive gripper, driven entirely by the arm, conforms to diverse objects through passive compliance. A structural model is developed, and a kinetostatics analysis is conducted to investigate isomorphic grasping configurations. To optimize performance, Particle-Swarm Optimization (PSO) is utilized to refine the gripper’s dimensional parameters, ensuring robust adaptability across various applications. Simulation results validate the UMLM’s easily implemented control strategy, operational versatility, and effectiveness in grasping diverse objects in dynamic environments. This work underscores the practical potential of underactuated metamorphic mechanisms in applications requiring efficient and adaptable loading solutions. Beyond the specific design, this generalized modeling and optimization framework extends to a broader class of manipulators, offering a scalable approach to the development of robotic systems that require efficiency, flexibility, and robust performance.

固定自由度（DoF）加载机构常常存在执行机构过多、控制复杂、对动态任务适应性有限等问题。本研究提出了一种欠驱动变形加载机械手（UMLM）的创新机制，将变形臂与被动自适应夹持器集成在一起。变形臂利用几何约束，实现拓扑重构和灵活的运动轨迹，而无需额外的致动器。自适应夹持器完全由手臂驱动，通过被动顺应来适应各种物体。建立了结构模型，并进行了动静力学分析，研究了同构抓取构型。为了优化性能，采用粒子群优化（PSO）方法对夹持器的尺寸参数进行优化，确保夹持器在各种应用中的鲁棒适应性。仿真结果验证了UMLM易于实现的控制策略、操作的通用性以及在动态环境中抓取不同目标的有效性。这项工作强调了欠驱动变质机制在需要高效和适应性负载解决方案的应用中的实际潜力。除了特定的设计之外，这种广义的建模和优化框架扩展到更广泛的机械手类别，为需要效率、灵活性和健壮性能的机器人系统的开发提供了可扩展的方法。

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引用次数: 0

On the lumped parameter modeling of worm gear mechanisms: Experimental validation and insights 蜗轮机构集总参数建模：实验验证与启示

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-12-01 Epub Date: 2025-10-22 DOI: 10.1016/j.mechmachtheory.2025.106266

Giulia Cristofori, Mattia Battarra, Emiliano Mucchi

A non-linear 8-DOF model capable of capturing the fundamentals of the worm gear dynamics has been developed. The model incorporates external excitations, non-linear time-varying meshing stiffness, and components related to friction phenomena. This study is dedicated to a thorough exposition of the lumped parameter model, accompanied by a comprehensive examination of its equations and an analysis of the impact of diverse contributions. The procedure employed to determine the meshing stiffness is further investigated using a finite element methodology, as it is a crucial input for the dynamic model. Furthermore, a comprehensive description of the experimental campaign conducted to validate the model is presented, enabling an in-depth analysis of the impact of speed and torque on the overall dynamics of worm gear mechanisms. In order to assess the capability of the model to accurately capture the effects of these two parameters, a comparison is made between the numerical results, specifically the bearing forces and transmission errors, and the experimental data. These comparisons facilitate the validation of the model.

一个非线性的8-DOF模型能够捕捉基本的蜗轮动力学已开发。该模型考虑了外部激励、非线性时变网格刚度和与摩擦现象相关的分量。本研究致力于对集总参数模型进行全面的阐述，同时对其方程进行全面的检查，并分析各种贡献的影响。用于确定网格刚度的程序使用有限元方法进行了进一步研究，因为它是动态模型的关键输入。此外，对验证模型的实验活动进行了全面的描述，从而能够深入分析速度和扭矩对蜗轮机构整体动力学的影响。为了评估模型准确捕捉这两个参数影响的能力，将数值结果（特别是轴承力和传动误差）与实验数据进行了比较。这些比较有助于模型的验证。

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引用次数: 0

Performance Influences and selection criteria for actuated joints on redundant parallel mechanisms—by two novel design examples 冗余并联机构驱动节点的性能影响及选择准则——以两个新颖的设计实例为例

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-12-01 Epub Date: 2025-10-21 DOI: 10.1016/j.mechmachtheory.2025.106263

Ju LI, Zhongqiu DU, Junjie SHE, Huiping SHEN

The selection of actuated joints in the limbs of redundant parallel mechanisms (RPMs) is a critical design challenge, as the number of limbs typically exceeds the degree of freedom (DOF). Despite its importance, this issue has received limited attention in the literature. This paper addresses the gap by proposing two examples of 2-DOF RPMs with redundant limbs, analyzing the impact of different actuated joints on the performance of RPMs. One example is a spatial two-translation RPM, and the other is a planar one-translation and one-rotation RPM. The influence of various actuated joints on the kinematic, stiffness, and dynamic performance of these RPMs is thoroughly examined under two actuated joint schemes. A comparative analysis reveals that each scheme has distinct advantages and disadvantages, making them suitable for different applications. Based on this analysis, the paper proposes application scenario requirement-based selection criteria for actuated joints of RPMs. This work provides a clear procedure for actuated joint selection and offers valuable insights into the design and application of RPMs.

冗余并联机构分支的驱动关节选择是一个关键的设计挑战，因为分支的数量通常超过了自由度。尽管它很重要，但这个问题在文献中得到的关注有限。本文通过给出两个具有冗余分支的2-DOF rpm实例，分析了不同驱动关节对rpm性能的影响，从而解决了这一问题。一个例子是空间两平移RPM，另一个例子是平面一平移一旋转RPM。在两种驱动关节方案下，深入研究了各种驱动关节对这些rpm的运动学、刚度和动态性能的影响。对比分析表明，每种方案都有其独特的优点和缺点，适合不同的应用。在此基础上，提出了基于应用场景需求的rpm驱动关节选择准则。这项工作为驱动关节的选择提供了一个清晰的程序，并为rpm的设计和应用提供了有价值的见解。

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引用次数: 0

Design of a passive spatial 2-DoF singularity-configurable gravity compensator for forearm and shank with roll-pitch motion 具有滚摇运动的臂、杆被动空间二自由度奇异可配置重力补偿器的设计

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-12-01 Epub Date: 2025-10-16 DOI: 10.1016/j.mechmachtheory.2025.106255

Yijia Peng, Jinrong Deng, Jian Song, Chaoqun Xiang

Passive gravity compensators (PGCs), distinguished by their compact and lightweight design, have been extensively applied in rehabilitation exoskeleton systems. However, existing spatial PGCs developed by pseudo-spatial gravity compensation mechanisms encounter singularities when the limb is oriented vertically, hence severely restricting their workspaces. This research presents a PGC specifically designed for the forearm and shank with roll-pitch motion, capable of positioning its singularity outside the limb's workspace by adjusting the twist angle while preserving perfect gravity compensation. A static balancing condition considering all masses is established, followed by an angle mapping mechanism utilizing a bevel differential and a timing-belt drive to achieve the required angular relationship. The perfect gravity balance is validated through simulations. Natural rubber bands (NRBs), characterized by their lightweight design, are utilized in the fabrication of zero-free-length springs (ZFLSs), with the maximum compensation error recorded at 8.42 % for the NRB measuring 30 mm in width and 3 mm in thickness. A wearable 2-DoF PGC prototype utilizing NRB-ZFLSs has been developed. The quantitative experiment revealed that the maximum compensation error is 10.43 % when the maximum gravity compensation torque is 5.04 Nm.

被动重力补偿器（PGCs）以其结构紧凑、重量轻的特点，在康复外骨骼系统中得到了广泛的应用。然而，现有的基于伪空间重力补偿机制的空间PGCs在肢体垂直定向时存在奇异性，严重限制了其工作空间。本研究提出了一种专门为具有滚转运动的前臂和小腿设计的PGC，该PGC能够在保持完美重力补偿的同时，通过调节扭转角度将其奇异点定位在肢体工作空间之外。建立了考虑所有质量的静平衡条件，然后利用锥面差速器和正时带传动的角度映射机构来实现所需的角度关系。通过仿真验证了完美的重力平衡。以轻量化设计为特点的天然橡皮筋（NRBs）用于零自由长度弹簧（ZFLSs）的制造，对于宽度为30 mm，厚度为3 mm的NRB，最大补偿误差为8.42%。利用nrb - zfls开发了一种可穿戴的2自由度PGC样机。定量实验表明，当最大重力补偿转矩为5.04 Nm时，最大补偿误差为10.43%。

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引用次数: 0

A novel heterogeneous polyhedral mechanism for shape morphing application 一种新型异质多面体变形机构

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-12-01 Epub Date: 2025-10-06 DOI: 10.1016/j.mechmachtheory.2025.106237

Weiming Guo, Jianguo Tao, Hong Xiao, Chen Yao, Hongwei Guo, Guang Yang, Rongqiang Liu

Shape morphing mechanisms (SMMs) have attracted significant interest due to their adaptive shape-change capabilities and superior controllability, particularly in aerospace applications. However, most existing rigid-body SMMs consist of planar mechanisms, which inherently limit their deformation to two dimensions. Three-dimensional(3D) SMMs are generally derived from polyhedral truss structures, yet the design methodologies for this transformation remain underexplored. This article introduces an innovative design methodology that employs loop theory and split vertex technology to convert truss structures into kinematic mechanisms, resulting in a novel SMM. The proposed mechanism significantly enhances continuous shape morphing capabilities in higher dimensions than existing SMMs. Then, a kinematic model is established to analyze the relationship between the transformation modes and distributed actuation. Finally, a two-module prototype SMM is fabricated, and morphing experiments are conducted. The results show that the innovative mechanism can achieve shape extension, spanwise bending, chordwise sweeping, twisting, and verify the effectiveness of the shape morphing model. This mechanism holds promise for advancing the rigid–flexible coupled morphing designs in future aircraft.

形状变形机制（SMMs）由于其自适应形状变化能力和优越的可控性而引起了人们的极大兴趣，特别是在航空航天应用中。然而，大多数现有的刚体smm由平面机构组成，这固有地限制了它们的二维变形。三维（3D） smm通常来源于多面体桁架结构，但这种转换的设计方法仍未得到充分探索。本文介绍了一种创新的设计方法，利用环理论和分裂顶点技术将桁架结构转化为运动机构，从而产生了一种新型的SMM。与现有的smm相比，该机制显著提高了在更高维度上的连续形状变形能力。然后，建立了运动学模型，分析了变换模式与分布式作动之间的关系。最后，制作了双模块SMM原型，并进行了变形实验。结果表明，该创新机构可以实现形状扩展、展向弯曲、弦向扫掠和扭转，验证了形状变形模型的有效性。该机构有望推进未来飞机的刚柔耦合变形设计。

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引用次数: 0