Mechanism and Machine Theory最新文献_第8页

Kinematics and performance analysis for single-loop deployable polygonal mechanisms based on deployable paths

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2025-01-07 DOI: 10.1016/j.mechmachtheory.2024.105907

Hao Chen , Gaohan Zhu , Weizhong Guo , Zhenghao Weng , Caizhi Zhou , Mingxuan Wang

{"title":"Kinematics and performance analysis for single-loop deployable polygonal mechanisms based on deployable paths","authors":"Hao Chen , Gaohan Zhu , Weizhong Guo , Zhenghao Weng , Caizhi Zhou , Mingxuan Wang","doi":"10.1016/j.mechmachtheory.2024.105907","DOIUrl":"10.1016/j.mechmachtheory.2024.105907","url":null,"abstract":"<div><div>Deployable polygonal mechanisms (DGMs) are widely used in various fields; however, their performance evaluation remains challenging due to limitations in existing indices. To address these shortcomings, this paper innovatively proposes several new evaluation indices for DGMs, aiming to improve the precision and comprehensiveness of performance analysis. Firstly, a velocity analysis method for single-loop DGMs based on deployable paths is introduced, eliminating the need to solve joint angle analytical expressions, reducing computational effort. Secondly, a method for calculating the transmission wrench screw of single-loop mechanisms is proposed. This method is applicable to overconstrained, non-overconstrained, and reconfigurable mechanisms, regardless of whether they possess a single or multiple degrees of freedom. Thirdly, an index for evaluating the deploying performance of <span><math><mi>n</mi></math></span>R DGMs that deploy into general planar polygons is developed, along with an algorithm for calculating folding length. Furthermore, novel evaluation indices for deploying<span><math><mo>/</mo></math></span>folding performance in various application scenarios, motion<span><math><mo>/</mo></math></span>force transmission performance, and transmission ratio stability are proposed. Finally, detailed analyses of deploying<span><math><mo>/</mo></math></span>folding performance, transmission ratio stability, global extreme velocity, global extreme stiffness, and motion<span><math><mo>/</mo></math></span>force transmission performance of <span><math><mi>n</mi></math></span>R DGMs are provided.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"206 ","pages":"Article 105907"},"PeriodicalIF":4.5,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143156095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analysis of multi-state meshing and dynamic stability of herringbone gears considering friction based on nonlinear dynamics

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2025-01-06 DOI: 10.1016/j.mechmachtheory.2024.105909

Zongxiang Yue , Zengcheng Wang , Zhaobo Chen , Jianjun Qu , Guangbin Yu , Jiazhi Wang , Shuai Mo

{"title":"Analysis of multi-state meshing and dynamic stability of herringbone gears considering friction based on nonlinear dynamics","authors":"Zongxiang Yue , Zengcheng Wang , Zhaobo Chen , Jianjun Qu , Guangbin Yu , Jiazhi Wang , Shuai Mo","doi":"10.1016/j.mechmachtheory.2024.105909","DOIUrl":"10.1016/j.mechmachtheory.2024.105909","url":null,"abstract":"<div><div>During the operation of herringbone gears some phenomena such as gear disengagement and back-side meshing (BSM) can lead to dynamic instability. Precise description of the behavior of multi-state meshing (MSM) is essential for the optimization of structures and for evaluation of its performance. In this article a nonlinear dynamic model for a herringbone gear is introduced. This model includes MSM and takes backlash and friction into account. MSM behavior is identified, and a dynamic stability rate (DSR) is calculated using various Poincaré maps. In addition, a number of bifurcation diagrams and phase diagrams are examined as well as the correlation between MSM characteristics and DSR. The study reveals that as the meshing frequency increases, the system transitions from stable periodic motion to complex periodic and chaotic responses before stabilizing into periodic motion. Transmission errors significantly influence MSM characteristics, with smaller errors making the DSR more sensitive to bifurcations and phase trajectory changes. Increased damping improves stability by suppressing BSM and chaotic motion. Under varying loads, the system transitions through different dynamic states, with periodic jumps notably affecting DSR at higher loads. Additionally, backlash plays a critical role in MSM behavior, influencing the transitions between periodic and chaotic responses. These findings highlight the importance of optimizing damping, load, and backlash to enhance the motion stability and performance of herringbone gear systems.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"206 ","pages":"Article 105909"},"PeriodicalIF":4.5,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143100779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A generalized method for C3 continuous toolpath planning and its application in robot machining

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2025-01-04 DOI: 10.1016/j.mechmachtheory.2024.105911

Guangxi Li , Haitao Liu , Qi Liu

{"title":"A generalized method for C3 continuous toolpath planning and its application in robot machining","authors":"Guangxi Li , Haitao Liu , Qi Liu","doi":"10.1016/j.mechmachtheory.2024.105911","DOIUrl":"10.1016/j.mechmachtheory.2024.105911","url":null,"abstract":"<div><div>High-order parametric continuity in toolpath generation and smooth passage through singular regions are paramount in five-axis machining. This paper introduces a generalized method for toolpath planning of a 5-DOF machining robot, which encompasses a two-pronged strategy: a toolpath smoothing technique and a singularity avoidance strategy. Initially, the control points of smoothing B-splines are analytically derived using curvature derivative continuity criteria for both linear and arc path segments. On this basis, an effective corner smoothing method, which is capable of addressing the line-line, line-arc, and arc-arc pairs, is developed for the tool position path, and a specialized approach similar to spatial arc-arc pair smoothing is employed for the tool orientation path. Subsequently, an analytical parameter synchronization technique is applied to generate a C<sup>3</sup> continuous toolpath. A real-time singularity avoidance strategy is then proposed to improve the toolpath continuity near the singular configuration of the machining equipment. The effectiveness of the proposed method is verified through simulations and experiments on a robot machining platform, with the integration of a jerk-continuous feedrate profile. The findings indicate that the equipment can operate effectively throughout its entire workspace thanks to the proposed toolpath planning method.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"206 ","pages":"Article 105911"},"PeriodicalIF":4.5,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143100778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A recursive method for determining long-period mesh stiffness of cylindrical gears considering real tooth surface deviations

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2025-01-03 DOI: 10.1016/j.mechmachtheory.2024.105898

Fengfeng Liu , Geng Liu , Lan Liu , Jingyi Gong

{"title":"A recursive method for determining long-period mesh stiffness of cylindrical gears considering real tooth surface deviations","authors":"Fengfeng Liu , Geng Liu , Lan Liu , Jingyi Gong","doi":"10.1016/j.mechmachtheory.2024.105898","DOIUrl":"10.1016/j.mechmachtheory.2024.105898","url":null,"abstract":"<div><div>A recursive method is proposed for determining long-period time-varying mesh stiffness (TVMS) of cylindrical gears, considering real tooth surface deviations. Due to variations in the real deviations of each gear tooth and the presence of hunting tooth pairs, the superposition of contact point deviations between the driving and driven gears results in a long period for the TVMS. A long-period recursive model of contact point deviation superposition is developed based on even mesh technique and tooth surface measurement technique. This model considers the matching relationships of contact elements and the forward and backward recursion relationships of each contact element over a long period. Furthermore, a loaded tooth contact analysis (LTCA) model with long-period superposition deviations is established, and a double-layer iterative algorithm is devised to solve for long-period TVMS and transmission error (TE). The validity of the proposed method is confirmed through tooth surface measurements and TE experiments. The effects of load, deviation superposition, and deviation size on long-period TVMS are investigated. Finally, the main frequency components in the TVMS spectrum that may cause low-frequency vibrations in gears are identified.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"206 ","pages":"Article 105898"},"PeriodicalIF":4.5,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143156091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Advantages of elliptical tip vanes on the kinematic design of balanced vane pumps

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2025-01-03 DOI: 10.1016/j.mechmachtheory.2024.105901

Caterina Natali, Mattia Battarra, Enrico Proner, Emiliano Mucchi

引用次数: 0

Design, analysis, and experimentation of deployable multi-closed-loop truss modules for aerospace platforms

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-12-31 DOI: 10.1016/j.mechmachtheory.2024.105897

Yang Zhang , Wenxuan Wang , Xi Kang , Bing Li

{"title":"Design, analysis, and experimentation of deployable multi-closed-loop truss modules for aerospace platforms","authors":"Yang Zhang , Wenxuan Wang , Xi Kang , Bing Li","doi":"10.1016/j.mechmachtheory.2024.105897","DOIUrl":"10.1016/j.mechmachtheory.2024.105897","url":null,"abstract":"<div><div>Deployable multi-closed-loop truss modules (MCLTMs) with a two-dimensional synchronous deployment motion, exhibit significant potential in constructing aerospace platforms due to their advantages of high stiffness and large deploying/folding ratio. This study addresses the kinematic and performance analysis of MCLTM and develops a prototype with optimized parameters. Firstly, the mobility and kinematic model of MCLTM are analyzed. Subsequently, three types of deploying/folding ratios for the modules are defined and analyzed. A stiffness analysis method for multi-closed-loop mechanisms is proposed. Utilizing the method, the stiffness model of the mechanism is established. Based on the stiffness model, stiffness performance indicators are defined and analyzed. The structure parameters of MCLTM are optimized based on the mapping curve between these performances and key design parameters. Finally, the prototype and the drive system are developed, and deployment and stiffness experiments are conducted to verify the feasibility of the mechanism and the correctness of kinematic and performance analyses. This work not only contributes to enriching and developing the theoretical system of deployable mechanisms but also provides a valuable reference for the prototype development of deployable mechanisms.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"205 ","pages":"Article 105897"},"PeriodicalIF":4.5,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fault-tolerant gait for Hexapod Robots with partial active joints locked

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-12-30 DOI: 10.1016/j.mechmachtheory.2024.105895

Qingxing Xi , Zhijun Chen , Ke Yin , Xu Liu , Feng Gao

{"title":"Fault-tolerant gait for Hexapod Robots with partial active joints locked","authors":"Qingxing Xi , Zhijun Chen , Ke Yin , Xu Liu , Feng Gao","doi":"10.1016/j.mechmachtheory.2024.105895","DOIUrl":"10.1016/j.mechmachtheory.2024.105895","url":null,"abstract":"<div><div>The fault-tolerant gait for legged robots can improve the reliability and prolong the service time. However, few fault-tolerant gaits are available for hexapod robots with parallel leg mechanisms to realize the walkability and adapt to rough terrains when several active joints locked. This paper proposes a fault-tolerant gait for hexapod robots based on the non-fault gait without changing its gait sequence. First, a hexapod robot with serial-parallel leg mechanism is introduced. Then, the fault-tolerant gait with partial active joints locked based on typical walking gait is proposed. The gait planning algorithm selects the minimum square sum of the displacements of the active joints as the objective function to improve the walking ability of the robot. Further, two examples are chosen to analyze the walking ability on ground and rough terrain. Finally, experiments are carried out to validate the fault-tolerant gait and its performances. The results show that the fault-tolerant gait can effectively solve the walking of hexapod robots with partial active joints locked and it can also walk in different directions and traverse rough terrains such as steps.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"205 ","pages":"Article 105895"},"PeriodicalIF":4.5,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Type synthesis and structure screening of deployable cellular mechanisms based on the graphical method and motion-force interaction performance

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-12-30 DOI: 10.1016/j.mechmachtheory.2024.105893

Qizhi Meng , Marco Ceccarelli

{"title":"Type synthesis and structure screening of deployable cellular mechanisms based on the graphical method and motion-force interaction performance","authors":"Qizhi Meng , Marco Ceccarelli","doi":"10.1016/j.mechmachtheory.2024.105893","DOIUrl":"10.1016/j.mechmachtheory.2024.105893","url":null,"abstract":"<div><div>With the increasing magnitude and complexity of space missions, coupled with higher energy collection and stronger signal transmission demands, support trusses of solar panels and antennas are evolving towards larger scales. Similar to assembling elements, the cellular mechanisms are crucial for achieving large-scale space structures. Following this concept, this paper focuses on type synthesis and structure screening of deployable cellular mechanisms. Considering the heightened reliability of revolute joints, the target mechanism exclusively incorporates such joints. First, a graphical-type synthesis method is introduced to synthesize deployable cellular mechanisms. Serialized deployable cellular mechanisms are designed utilizing the 2Pa (Pa: parallelogram mechanism) and 4R (R: revolute joint) kinematic chains as backbone mechanisms. Subsequently, structure screening of deployable cellular mechanisms is carried out by motion-force interaction performance analysis with the power coefficient as a criterion. Then workspaces with different motion-force interaction performances are identified for the selected deployable cellular mechanisms. Prototype construction and test show that the proposed mechanisms achieve one-degree-of-freedom deployable movement. The proposed deployable cellular mechanisms are expected to play significant roles in constructing deployable modules.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"205 ","pages":"Article 105893"},"PeriodicalIF":4.5,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An empirical analytical method to determine the human walking ground reaction force at known speeds

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-12-30 DOI: 10.1016/j.mechmachtheory.2024.105903

Zehao Hou , Huan Zhao , Wei-Hsin Liao , Chris R. Bowen , Daniel J. Inman , Junyi Cao , Kangqi Fan

{"title":"An empirical analytical method to determine the human walking ground reaction force at known speeds","authors":"Zehao Hou , Huan Zhao , Wei-Hsin Liao , Chris R. Bowen , Daniel J. Inman , Junyi Cao , Kangqi Fan","doi":"10.1016/j.mechmachtheory.2024.105903","DOIUrl":"10.1016/j.mechmachtheory.2024.105903","url":null,"abstract":"<div><div>The experimental analysis of biomechanical energy harvesting is typically conducted at known speeds. However, the theoretical mapping of walking speed to the ground reaction force is often constrained by the inherent complexity of the energy conservation method commonly applied to solve the spring roller foot model in engineering applications. Consequently, an empirical analytical method has been proposed to address this challenge. This analytical method mathematically models human walking using time-varying spring stiffness. The empirical analytical method is developed based on an empirical gait division ratio of 3:1 and further refined by incorporating the leg swing effect. A comparison between the proposed method and the energy conservation method reveals that the proposed method offers several advantages, including a simple solving process, accurate and unique solutions, and predictions that are independent of prior data. Finally, the proposed empirical analytical method is validated using four distinct datasets, demonstrating its superior capability in predicting ground reaction forces during human walking at known speeds.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"205 ","pages":"Article 105903"},"PeriodicalIF":4.5,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Kinematic performance evaluation of a bioinspired 5-DOF parallel driving mechanism with multi-loop coupled chain

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-12-27 DOI: 10.1016/j.mechmachtheory.2024.105896

Hanqing Shi , Jinzhu Zhang , Tao Wang , Qingxue Huang

{"title":"Kinematic performance evaluation of a bioinspired 5-DOF parallel driving mechanism with multi-loop coupled chain","authors":"Hanqing Shi , Jinzhu Zhang , Tao Wang , Qingxue Huang","doi":"10.1016/j.mechmachtheory.2024.105896","DOIUrl":"10.1016/j.mechmachtheory.2024.105896","url":null,"abstract":"<div><div>This paper deals with the kinematic performance evaluation of a bioinspired 5-DOF parallel driving mechanism (PDM) PRTU-X5. The PRTU-X5 consists of five open-loop active limbs and one passive hybrid kinematic chain. To tackle the challenge of evaluating the kinematic performance of this 5-DOF PDM with multi-loop coupled kinematic chains, this study presents a divide-and-conquer based evaluation strategy, utilizing the functional sequences and kinematic decoupling to simplify the complex mechanism topology analysis issue into sub-issues of sub-mechanism systems. The local evaluation indices of the sub-mechanisms are derived by integrally utilizing the transmission and interaction performance evaluation criteria. The local comprehensive evaluation index (LCEI) is then defined. Under the guidance of the bionic motion atlas of manual two-arm cooperation, the positioning and orientation capability are evaluated. Finally, the performance maps are plotted to visualize the kinematic performance of the PRTU-X5. The evaluation results show the feasibility and validity of the proposed strategy and indices and provide a foundation for the dimension optimization of the PRTU-X5. This work can serve as a reference for other parallel mechanisms with complex mechanism topology.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"205 ","pages":"Article 105896"},"PeriodicalIF":4.5,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0