Mechanism and Machine Theory最新文献_第7页

Dynamics representation of mechanical systems for time-stepping problems 机械系统时间步进问题的动力学表示

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-11-19 DOI: 10.1016/j.mechmachtheory.2025.106292

David M. Solanillas Francés , József Kövecses

This paper introduces a novel two-stage time-stepping framework for mechanical systems. The method separates the update of configuration and dynamics: configuration is advanced using independent (joint) velocities, while the dynamic equations are formulated using a dependent set of velocities—specifically, the velocity of body-fixed points and the angular velocity of each rigid body. These dependent velocities are projected onto the joint space to ensure that kinematic constraints are satisfied at the position level, eliminating the need for constraint stabilization techniques. A key advantage of this decomposition is that it enables a compact and transparent expression of the nonlinear inertial terms, which can then be integrated either explicitly or implicitly within the same framework. This flexibility makes the approach particularly well suited for time-stepping schemes, including those used in challenging scenarios such as unilateral contact problems. Numerical results illustrate how different integration strategies and velocity representations affect the stability and accuracy of the solution, highlighting the robustness of the proposed method.

本文介绍了一种新的机械系统两阶段时间步进框架。该方法将构型更新和动力学更新分离开来：构型使用独立的（关节）速度推进，而动力学方程则使用一组相关的速度-具体地说，是体固定点的速度和每个刚体的角速度。这些相关的速度被投射到关节空间，以确保在位置水平上满足运动学约束，从而消除了约束稳定技术的需要。这种分解的一个关键优点是它支持非线性惯性项的紧凑和透明的表达，然后可以将其显式或隐式地集成在同一框架中。这种灵活性使得该方法特别适合于时间步进方案，包括用于具有挑战性的场景，如单边接触问题。数值结果说明了不同的积分策略和速度表示如何影响解的稳定性和准确性，突出了所提方法的鲁棒性。

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引用次数: 0

Singularity analysis and identification of a novel (6+1)-DOFs kinematically redundant parallel mechanism based on Grassmann line geometry 基于格拉斯曼线几何的新型（6+1）自由度冗余并联机构奇异性分析与辨识

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-11-15 DOI: 10.1016/j.mechmachtheory.2025.106258

Xiao Li , Haibo Qu , Yili Kuang , Giuseppe Carbone , Sheng Guo

This paper addresses the challenges in analyzing and identifying singularities in a novel (6+1) degrees of freedom (DOFs) kinematically redundant parallel mechanism (KRPM) using Grassmann line geometry. First, the structural features and DOFs analysis of the mechanism are presented, followed by a clear explanation of the process for solving its inverse kinematics problem. Next, a method combining the global Jacobian matrices with sub-Jacobian matrices is proposed for singularity analysis, which helps to avoid false positives and negatives when identifying singularities based solely on the global Jacobian matrix. Additionally, the degradation of different linear subspaces corresponding to the singularities of the global forward Jacobian matrix is explored using the Grassmann line geometry. Finally, a new singularity classification and identification method based on geometric conditions is introduced, providing an intuitive approach for identifying singular configurations through singular coordinates. The results contribute to the comprehensive singularity analysis of KRPMs and offer an effective method for identifying singular configurations in certain three-limbed 6-DOFs symmetric parallel mechanisms.

本文解决了利用格拉斯曼线几何分析和识别一种新型（6+1）自由度（DOFs）运动冗余并联机构（KRPM）奇异性的挑战。首先介绍了该机构的结构特点和自由度分析，然后对其逆运动学问题的求解过程进行了清晰的说明。其次，提出了一种将全局雅可比矩阵与子雅可比矩阵相结合的奇异点分析方法，避免了单纯基于全局雅可比矩阵识别奇异点时的假阳性和假阴性。此外，利用Grassmann线几何探讨了全局正雅可比矩阵奇异点对应的不同线性子空间的退化问题。最后，提出了一种基于几何条件的奇异分类与识别方法，为利用奇异坐标识别奇异构型提供了一种直观的方法。所得结果有助于krpm的综合奇异性分析，并为确定特定三肢六自由度对称并联机构的奇异构型提供了一种有效的方法。

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引用次数: 0

Research on the natural frequencies and mode shapes of a single gimbal control moment gyro considering internal rotor flexibility and gimbal rotation effects 考虑转子内柔度和云台旋转效应的单云台控制力矩陀螺固有频率和振型研究

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-11-15 DOI: 10.1016/j.mechmachtheory.2025.106289

Miao Xue , Jianghai Miao , Wei Pu

Natural frequencies and mode shapes are crucial to understanding the transmission path of harmonic disturbances in a control moment gyro system. However, no analytical model has yet been developed for identifying the mechanism of the micro-vibration characteristics observed in experiments. In this study, a semi-analytical model was established to analyze the micro-vibration mechanisms and natural frequencies of the high-speed rotor in a control moment gyro considering rotor flexibility, nonlinear effects of supporting bearings and gimbal rotation. The disturbance frequency characteristics of the support bearings were empirically determined through experimental observations. The governing equations of a single-gimbal control moment gyro were derived by using the Newton–Euler method. The model was validated in experiments measuring representative micro-vibration responses. The effects of rotor flexibility and gimbal rotation on the first several natural characteristics were quantitatively analyzed. The results indicated that gimbal rotations had notable influences on natural frequencies and stiffness of supporting bearings. This study provides deep insights into vibration analysis and structural optimization for designing ultra-precision control moment gyros.

固有频率和模态振型对于理解控制力矩陀螺系统中谐波扰动的传输路径至关重要。然而，目前还没有建立分析模型来确定实验中观察到的微振动特性的机理。考虑转子柔性、支承轴承的非线性效应和云台旋转的影响，建立了控制力矩陀螺高速转子微振动机理和固有频率的半解析模型。通过实验观察，经验确定了支承轴承的扰动频率特性。采用牛顿-欧拉法推导了单框架力矩陀螺的控制方程。该模型已在具有代表性的微振动响应测试中得到验证。定量分析了转子柔性和框架旋转对前几项自然特性的影响。结果表明，框架旋转对支承轴承的固有频率和刚度有显著影响。该研究为超精密控制力矩陀螺的振动分析和结构优化设计提供了深入的见解。

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引用次数: 0

A two degrees of freedom robotic hand for grasping and intra-palmar fine manipulation 一个二自由度机械手，用于抓握和掌内精细操作

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-11-13 DOI: 10.1016/j.mechmachtheory.2025.106291

Zhen Yuan , Erke Qin , Zhihao Xu , Penghua Zhang , Ruoxiang Huang , Rongjie Kang , Jian S. Dai , Zhibin Song

Grasp generalisation ability and intra-palmar manipulation ability are important functions of robotic hands. Currently, most robotic hands with these two abilities have a human-like structure with an excessive number of degrees of freedom, results in a complex and costly design that can hinder their practical application in scenarios prioritizing cost-effectiveness and simplicity. In response to this issue, this paper presents a new design for a robotic hand with three fingers and two degrees of freedom, capable of grasping and intra-palmar manipulation. This streamlined motion style, which combines a grasping degree of freedom and a twisting degree of freedom, can perform most hand grasping actions as well as intra-palmar manipulation without the need for wrist compensation. A theoretical model of the mechanism's motion and a force coupling model have been established, as well as a prototype. The robotic hand performance evaluation experiments and the force coupling compensation experiments are implemented. Experimental results verify that the robotic hand has strong grasping ability, fine intra-palmar manipulation ability and large load capacity. The proposed robotic hand provides a new solution for manipulation tools.

抓握泛化能力和掌内操作能力是机器人手的重要功能。目前，大多数具有这两种能力的机器人手都具有类似人的结构，自由度过多，导致设计复杂且成本高昂，这可能阻碍它们在优先考虑成本效益和简单性的场景中的实际应用。针对这一问题，本文提出了一种新的三指二自由度机械人手的设计，具有抓握和掌内操作的能力。这种流线型的运动风格，结合了抓握自由度和扭转自由度，可以执行大多数手抓握动作以及掌内操作，而不需要手腕补偿。建立了机构运动的理论模型和力耦合模型，并制作了样机。进行了机械手性能评价实验和力耦合补偿实验。实验结果表明，该机械手具有较强的抓取能力、良好的掌内操作能力和较大的承载能力。提出的机械手为操作工具提供了一种新的解决方案。

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引用次数: 0

Modeling nonlinear deflections of initially curved beams with large curvatures 大曲率初弯曲梁的非线性挠度建模

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-11-13 DOI: 10.1016/j.mechmachtheory.2025.106290

Nan Yang, Ruiyu Bai, Jiaqiang Yao, Bo Li, Guimin Chen

Understanding and modeling nonlinear deflections of compliant components are the major challenges of designing compliant mechanisms. Initially curved beams, can exhibit diverse mechanical behaviors, serving as useful alternatives to straight beams in compliant mechanisms. This paper presents a closed-form model for intermediate deflections of circular beams with normalized curvatures up to

\pm π / 4

, in which Taylor series expansion and truncation are employed. By combining this model with the chained scheme, it can capture large deflections of initially curved beams with a very small discretization number, considerably reducing the computational complexity. An experimental validation and the results comparison of the proposed model with nonlinear finite element models and the previous chained beam constrained model on three examples are provided, demonstrating its accuracy and efficiency. The model presented in this work offers a parameterized tool for designing the compliant mechanisms containing initially curved beams with large curvatures and constant sections.

理解和建模柔性部件的非线性挠度是设计柔性机构的主要挑战。最初弯曲梁，可以表现出不同的力学行为，作为有用的替代品，直梁在柔性机构。本文提出了曲率为±π/4的归一化圆梁的中间挠度的封闭模型，该模型采用泰勒级数展开和截断。将该模型与链式方案相结合，可以以很小的离散化次数捕获初始弯曲梁的大挠度，大大降低了计算复杂度。最后通过3个算例，将所提模型与非线性有限元模型和先前的链梁约束模型进行了实验验证和结果比较，验证了所提模型的准确性和有效性。本工作中提出的模型为设计包含具有大曲率和恒定截面的初始弯曲梁的柔性机构提供了一个参数化工具。

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引用次数: 0

Control parameter design method for multi-axis machine tools based on graphical implementation 基于图形化实现的多轴机床控制参数设计方法

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-11-12 DOI: 10.1016/j.mechmachtheory.2025.106293

Jinyin Zhou , Haoyu Liu , Jun Wu , Xiaoqin Hao

Due to the complexity of multi-axis machine tools, control parameters are generally tuned by engineers and the control performance is not optimal in terms of servo matching. In this paper, a new control-parameter design method for multi-axis machine tools to reduce contour error is proposed. The prescribed amplitude/phase responses at the trajectory’s dominant frequency are set as functions of a constraint parameter. The constraint parameter aligns all axes’ phase at the dominant frequency, which can be used to balance the trajectory amplitude error at the dominant frequency and the phase discrepancy among the axes at the non-dominant frequencies of the trajectory. By designing an appropriate constraint parameter, the multi-axis servo matching of the machine tool can be realized. Amplitude, phase and overshoot are mapped to circles and lines in the control parameter plane. The intersection of the prescribed amplitude and phase curves yields the desired control parameters. Experiments on a five-axis machine tool show that the method achieves better results than manual adjustment on various periodic trajectories.

由于多轴机床的复杂性，控制参数一般由工程师自行调整，在伺服匹配方面控制性能并非最优。提出了一种减少多轴机床轮廓误差的控制参数设计方法。在轨迹主频率处的规定幅度/相位响应被设置为约束参数的函数。该约束参数将各轴在主导频率处的相位对齐，可用于平衡主导频率处的弹道幅值误差和非主导频率处各轴之间的相位差。通过设计合适的约束参数，可以实现机床的多轴伺服匹配。幅度、相位和超调量在控制参数平面上被映射成圆和线。规定幅度和相位曲线的交点产生所需的控制参数。在五轴机床上的实验表明，该方法在各种周期轨迹上的调整效果优于手动调整。

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引用次数: 0

Development and validation of a rigid-flexible hybrid robotic leg with structural compliance and intrinsic contact sensing capability 具有结构柔度和内在接触传感能力的刚柔混合机器人腿的研制与验证

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-11-10 DOI: 10.1016/j.mechmachtheory.2025.106271

Shujie Tang , Siyue Yao , Xingyue Zhu , Tao Yu , Hao Wang , Haoyong Yu , Genliang Chen

Elastic elements in robotic legs offer benefits in terms of adaptability, energy efficiency, and robustness. This paper presents a novel concept of a robotic leg with a fully elastic arc-shaped link that serves as both a structural component for motion transmission and a leaf spring. This unique design endows the robotic leg with structural compliance, which is particularly advantageous for impact absorption during interactions with the environment. Furthermore, the deformation of the elastic link enables intrinsic contact sensing capability. A compact deflection sensor capable of measuring large-scale deformations was developed and integrated with the elastic link. A contact sensing model was derived using a discretization-based approach to predict the foot contact force and position by leveraging elastic deformation and hip motor torque. Various experimental validations were performed using the fabricated prototype. The results demonstrate a 35% reduction in the impact loads compared to those of a rigid counterpart. Moreover, foot contact force sensing and control in both static and dynamic scenarios were achieved, and useful terrain information was obtained using the sensed force.

机器人腿中的弹性元件在适应性、能效和健壮性方面提供了好处。本文提出了一种具有全弹性弧形连杆的机器人腿的新概念，该连杆既是运动传动的结构部件，又是钢板弹簧。这种独特的设计使机器人腿具有结构顺应性，这对与环境相互作用时的冲击吸收特别有利。此外，弹性连杆的变形使其具有固有的接触传感能力。研制了一种能够测量大尺度变形的紧凑型挠度传感器，并与弹性连杆集成。利用弹性变形和髋关节电机扭矩，采用离散化方法建立了足部接触力和位置预测的接触传感模型。利用制作的样机进行了各种实验验证。结果表明，与刚性材料相比，冲击载荷减少了35%。实现了静态和动态两种场景下的足部接触力传感与控制，并利用传感力获取有用的地形信息。

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引用次数: 0

Advances in generalized parallel mechanisms: Coupling, configurable, and articulated designs 广义并联机构的进展：耦合、可配置和铰接设计

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-11-08 DOI: 10.1016/j.mechmachtheory.2025.106287

Zhihao Xia , Yongheng Xing , Chunxu Tian , Dan Zhang

This paper reviews recent advancements in Generalized Parallel Mechanisms (GPMs), which extend the capabilities of Conventional Parallel Mechanisms (CPMs) through innovative designs featuring coupling sub-chains, configurable platforms, and articulated platforms. Firstly, the in-depth classification of GPMs is emphasized and the design principles, kinematic analysis, and performance evaluation are detailed to enhance their application capabilities. Then, this paper develops into the analysis of characteristics and performance, covering aspects such as reconfiguration characteristics, workspace performance, and singularity analysis, which are crucial for understanding and optimizing the behavior and efficiency of mechanisms. Furthermore, the key challenges in GPMs are emphasized, including the need for systematic type synthesis methods, clearer motion description frameworks, and comprehensive performance analysis tools that incorporate workspace, singularity, motion/force transmissibility, and various performance indicators. It also highlights future research directions to enhance potential of GPMs in automation and robotics. Finally, this paper presents a comprehensive overview of the practical applications across different fields, including grasping, locomotion, and origami mechanisms. It highlights how GPMs leverage their unique design features to enhance performance, adaptability, and efficiency in various engineering and robotic tasks.

本文综述了广义并联机构（gpm）的最新进展，通过耦合子链、可配置平台和铰接平台的创新设计，扩展了传统并联机构（CPMs）的能力。首先，对gpm进行了深入分类，详细介绍了gpm的设计原则、运动学分析和性能评价，以提高gpm的应用能力。在此基础上，对机构的特性和性能进行分析，包括重构特性、工作空间性能和奇异性分析等，这些对理解和优化机构的行为和效率至关重要。此外，强调了gpm的关键挑战，包括需要系统的类型综合方法，更清晰的运动描述框架，以及综合工作空间，奇点，运动/力传递率和各种性能指标的综合性能分析工具。强调了未来的研究方向，以增强gpm在自动化和机器人领域的潜力。最后，本文全面概述了在不同领域的实际应用，包括抓握、运动和折纸机制。它强调了gpm如何利用其独特的设计特性来提高各种工程和机器人任务的性能、适应性和效率。

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引用次数: 0

Revisiting third‑order tooth‑contact analysis of hypoid and bevel gears via the Darboux moving‑frame 通过Darboux动架重新进行准双曲面齿轮和锥齿轮的三阶齿接触分析

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-11-07 DOI: 10.1016/j.mechmachtheory.2025.106270

Zhang-Hua Fong (chair professor), Wei-Jen Chen (Ph.D. candidate)

Local synthesis enables hypoid and bevel gear designers to control the tooth-contact pattern and transmission error (TE) by prescribing curvature-level targets and computing the surfaces that achieve them. While second-order contact analysis is well established, robust performance under load and misalignment often requires third-order geometric compatibility—a step many practitioners avoid due to its algebraic complexity. This paper presents a systematic third-order tooth-contact framework based on the Darboux moving-frame formalism. The first- and second-order meshing relations are cast as two coupled systems of five equations in five unknowns, enabling direct numerical or symbolic solution for the principal curvatures, their derivatives, and the in-plane connection-form derivatives of the generated surface. The formulation naturally yields the angular-velocity ratio and angular accelerations without ad hoc assumptions. A symbolic implementation reproduces a published numerical example from Advanced Theories of Hypoid Gears, confirming consistency. The method provides a rigorous analytical basis for curvature-based local synthesis and supports designs with improved contact stability, reduced TE, and lower sensitivity to misalignment.

局部合成使准双曲面和锥齿轮设计人员能够通过规定曲率级目标和计算实现这些目标的表面来控制齿接触模式和传动误差（TE）。虽然二阶接触分析已经很好地建立，但在载荷和不对准下的鲁棒性能通常需要三阶几何兼容性——由于其代数复杂性，许多从业者避免了这一步。基于达布运动框架形式，提出了一种系统的三阶齿-接触框架。将一阶和二阶网格关系转换为五个未知数的五个方程的两个耦合系统，从而可以直接数值或符号求解主曲率及其导数以及生成曲面的平面内连接形式导数。该公式自然地得出角速度比和角加速度，而不需要特别的假设。一个符号实现再现了《准双曲面齿轮高级理论》中发表的一个数值例子，证实了一致性。该方法为基于曲率的局部合成提供了严格的分析基础，并支持具有改善接触稳定性，降低TE和降低对不对准灵敏度的设计。

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引用次数: 0

MADDPG-based energy management strategy for multi-mode distributed drive electric bus 基于madpg的多模分布式驱动电动客车能量管理策略

IF 4.5 1区工程技术 Q1 ENGINEERING, MECHANICAL

Mechanism and Machine Theory

Pub Date : 2025-11-07 DOI: 10.1016/j.mechmachtheory.2025.106284

Ying Li , Jiageng Ruan , Zexuan Han , Jingjing Hu , He Wan

The distributed electric drive powertrain is one of the most promising ways to electrify and decarbonize heavy-duty vehicles. To improve the energy efficiency and driving comfort of distributed drive electric buses, this study proposes an Energy Management Strategy based on the Hybrid-Action Multi-Agent Deep Deterministic Policy Gradient algorithm (HA-MADDPG). The MADDPG algorithm enhances the EMS's adaptability and rapid response in varying environments through centralized training and decentralized execution strategy. Considering that single-motor and dual-motor driving modes are available, a rule-learning combined strategy is applied to select discrete driving modes, which adopts a look-up table to determine the single-motor mode, while continuous actions simulate the selection of the dual-motor driving mode. Expert experience is introduced in the HA-MADDPG to guide exploration and correct the unreasonable exploration by Agents, which accelerates the training speed and improves training quality. Results show that the proposed HA-MADDPG EMS improves energy efficiency by up to 1.59 % compared with the Real-time Rule-based EMS, which is widely adopted in real vehicles. Compared with theoretically Optimal Rule-based EMS, HA-MADDPG-based EMS achieves similar energy performance with fewer mode switching actions.

分布式电力驱动动力系统是重型汽车电气化和脱碳最有前途的方法之一。为了提高分布式驱动电动客车的能源效率和驾驶舒适性，提出了一种基于混合行动多智能体深度确定性策略梯度算法（HA-MADDPG）的能源管理策略。该算法通过集中训练和分散执行策略，增强了EMS在不同环境下的适应性和快速响应能力。考虑到有单电机和双电机两种驱动模式，采用规则学习组合策略进行离散驱动模式选择，采用查表法确定单电机驱动模式，连续动作模拟双电机驱动模式的选择。在HA-MADDPG中引入专家经验，引导agent进行探索，纠正agent不合理的探索，加快了训练速度，提高了训练质量。结果表明，与实际车辆中广泛采用的基于实时规则的系统相比，所提出的HA-MADDPG系统的能效提高了1.59%。与理论上最优的基于规则的EMS相比，基于ha - maddpg的EMS以更少的模式切换动作实现了相似的能量性能。

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引用次数: 0