Mechanism and Machine Theory最新文献_第8页

A family of folding single-loop metamorphic mechanisms for aerospace manipulators: Synthesis, network, and analysis 用于航空航天机械手的折叠式单环变态机构系列：合成、网络和分析

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-07-18 DOI: 10.1016/j.mechmachtheory.2024.105728

{"title":"A family of folding single-loop metamorphic mechanisms for aerospace manipulators: Synthesis, network, and analysis","authors":"","doi":"10.1016/j.mechmachtheory.2024.105728","DOIUrl":"10.1016/j.mechmachtheory.2024.105728","url":null,"abstract":"<div><p>Guided by predetermined degrees of freedom for different desired tasks, the type synthesis of single-loop metamorphic mechanisms (SLMMs) has long posed a challenge. Owing to the complexity and coupling of their overconstraints and the variability of constraints arising from bifurcation motions, it is difficult to ensure geometric coordination and synchronous motion for a network of multiple SLMMs. Here, we propose an approach to type synthesize SLMMs using the atlas method. A novel family of SLMMs is further synthesized. The mobility analysis of a selected 7R SLMM is carried out via screw theory. The kinematics and bifurcation phenomena are analyzed and verified through numerical simulation using computer-aided design models. To evaluate the performance of the SLMMs, the mapping relationship between key design parameters and performance indicators, such as the grasping angle, folding angle, and mechanical advantage, is studied. A networking method is then proposed by considering the geometric coordination conditions and variation of the overconstraints of SLMMs. Prototypes of an SLMM and manipulator with optimal geometrical parameters are developed to verify the feasibility and correctness of the proposed method and kinematic analysis.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141729004","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

Design and evaluation of a four-DoF upper limb exoskeleton with gravity compensation 具有重力补偿功能的四DoF上肢外骨骼的设计与评估

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-07-16 DOI: 10.1016/j.mechmachtheory.2024.105746

{"title":"Design and evaluation of a four-DoF upper limb exoskeleton with gravity compensation","authors":"","doi":"10.1016/j.mechmachtheory.2024.105746","DOIUrl":"10.1016/j.mechmachtheory.2024.105746","url":null,"abstract":"<div><p>Gravity compensation (GC) mechanisms are commonly employed to either support limb gravity in passive exoskeletons or decrease motor power for safe human-robot interaction in active exoskeletons. This paper proposes a four-degree-of-freedom (DoF) upper limb exoskeleton with a theoretically perfect GC system, incorporating three DoFs in the shoulder and one DoF in the elbow. Paired with the anthropomorphic structure, the compact and adjustable GC system housed within the exoskeleton's linkages, reduces limitations on the limb's motion range and facilitates the integration of actuators for an active system. First, the GC system is designed through the analysis of potential energy equations, employing five cable-pulley-spring based units interconnected by parallel and differential mechanisms. Subsequently, the mechanical structure of the exoskeleton is developed, and the theoretically perfect GC in the quasi-static state is verified through numerical calculations. Then, the prototype is fabricated, and its actual performance is evaluated through experiments. The experimental results demonstrate the effectiveness of the exoskeleton with GC. Finally, a potential solution for the integration of actuators is demonstrated, and the limitation of the proposed system is also well discussed.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141623105","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

Dynamic characteristics of rigid-elastic-liquid-coupled ball bearings considering elastohydrodynamic lubrication 考虑弹性流体动力润滑的刚-弹-液耦合球轴承的动态特性

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-07-14 DOI: 10.1016/j.mechmachtheory.2024.105727

Yan Li, Yongcun Cui, Sier Deng

{"title":"Dynamic characteristics of rigid-elastic-liquid-coupled ball bearings considering elastohydrodynamic lubrication","authors":"Yan Li, Yongcun Cui, Sier Deng","doi":"10.1016/j.mechmachtheory.2024.105727","DOIUrl":"https://doi.org/10.1016/j.mechmachtheory.2024.105727","url":null,"abstract":"<div><p>The nonlinear characteristics of aero-engine spindle bearings remain unclear. To better reveal these characteristics, a ball bearing coupled with an elastic-ring squeeze film damper (ERSFD) and a squirrel cage was investigated in this work. With the elastohydrodynamic lubrication theory, a dynamic equation for a rigid-elastic-liquid-coupled ball bearing under high-speed and high-axial-load conditions was established. The Runge–Kutta method and the iterative Newton–Broyden method were applied to solve the coupling equation. The effects of the axial load and bearing speed on the bearing capacity and dynamic stiffness were analyzed. The dynamic characteristics of its bearing outer ring operating at different speeds and axial loads were studied through a numerical analysis. Finally, the theoretical model was tested and verified. The results indicated that the axial load and bearing speed significantly affect its bearing capacity and dynamic stiffness. Its vibration reduction performance of the bearing at a relatively low bearing speed and high axial load was relatively good when considering elastohydrodynamic lubrication. This work lays some references for optimal design of the spindle bearings of aero-engines.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141606374","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 adaptive lumped-mass dynamic model and its control application for continuum robots 自适应块状质量动态模型及其在连续机器人中的控制应用

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-07-14 DOI: 10.1016/j.mechmachtheory.2024.105736

引用次数: 0

Force and time-optimal trajectory planning for dual-arm unilateral cooperative grasping 双臂单侧合作抓取的力和时间最优轨迹规划

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-07-14 DOI: 10.1016/j.mechmachtheory.2024.105729

Roberto Di Leva , Hubert Gattringer , Andreas Müller , Marco Carricato

{"title":"Force and time-optimal trajectory planning for dual-arm unilateral cooperative grasping","authors":"Roberto Di Leva , Hubert Gattringer , Andreas Müller , Marco Carricato","doi":"10.1016/j.mechmachtheory.2024.105729","DOIUrl":"https://doi.org/10.1016/j.mechmachtheory.2024.105729","url":null,"abstract":"<div><p>This paper studies the dual-arm manipulation of an object by means of two collaborative robots. The latter hold the object through limited contact areas, thus applying unilateral contact constraints. This manipulation strategy increases versatility, since it does not require specific grippers depending on the object shape and size. However, to ensure grasping stability (i.e. no slipping of the object), a suitable internal force must be prescribed to ensure the fulfillment of the static-friction condition. In this work, the trend of the internal force is included among the inputs of a time-optimal trajectory planning, in order to find the minimal internal prestress that is able to both satisfy the static-friction condition and manipulate the object in minimal time. Admittance control is used to modulate the forces exerted by the robot end-effectors on the object. An extensive experimentation, on different 6-dimensional trajectories reaching linear and angular accelerations up to 4.5 m/s<sup>2</sup> and 7.4 rad/s<sup>2</sup>, is presented and discussed.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0094114X24001563/pdfft?md5=5ae6f7c4c14070b73651090a6ddbcee9&pid=1-s2.0-S0094114X24001563-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141606043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prediction of the maximum tooth root stress for fatigue analysis of highly crowned spherical gear couplings working at high misaligned conditions 高齿冠球面齿轮联轴器疲劳分析的最大齿根应力预测

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-07-14 DOI: 10.1016/j.mechmachtheory.2024.105732

{"title":"Prediction of the maximum tooth root stress for fatigue analysis of highly crowned spherical gear couplings working at high misaligned conditions","authors":"","doi":"10.1016/j.mechmachtheory.2024.105732","DOIUrl":"10.1016/j.mechmachtheory.2024.105732","url":null,"abstract":"<div><p>Spherical gear couplings efficiently transfer power between highly misaligned rotating shafts, featuring high longitudinal crowning in their design. At high misalignment angles, the contact point shifts across the face width, reducing the number of teeth in contact and increasing the risk of tooth root fatigue failure.</p><p>While gear coupling fatigue sizing standards typically address misalignment angles above one degree as special cases, many applications involve misalignment angles exceeding 3°. This paper proposes a surrogate modeling approach to predict maximum tooth root stress for fatigue analysis of spherical gear couplings operating under misaligned conditions. Results indicate that this cannot be predicted in an independent manner from the number of teeth in contact or the effective face width. Consequently, demonstrates that using a single coefficient to account for the effect of the misalignment on load distribution yields optimal results. This research validates the suitability of the presented methodology for predicting tooth root stresses in spherical gear couplings prone to tooth root fatigue failure under high misalignment conditions with a mean error of 0.4%, while it serves as a valuable fast tool for engineers during the design phase.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141623103","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

Multiple terrain traversal capabilities based mechanism dimension design for a six-legged robot using performance charts from analytical conditions 利用分析条件下的性能图表，为六足机器人设计基于多种地形穿越能力的机构尺寸

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-07-13 DOI: 10.1016/j.mechmachtheory.2024.105731

Xin Xu , Chenkun Qi , Liangliang Han , Zhijun Chen , Feng Gao , Weijun Wang , Meng Chen , Xianbao Chen

{"title":"Multiple terrain traversal capabilities based mechanism dimension design for a six-legged robot using performance charts from analytical conditions","authors":"Xin Xu , Chenkun Qi , Liangliang Han , Zhijun Chen , Feng Gao , Weijun Wang , Meng Chen , Xianbao Chen","doi":"10.1016/j.mechmachtheory.2024.105731","DOIUrl":"https://doi.org/10.1016/j.mechmachtheory.2024.105731","url":null,"abstract":"<div><p>Six-legged robots possess powerful terrain traversal capabilities. To achieve small mechanism dimensions that meet these capabilities is crucial for reducing weight and size. Traditional try-and-verify design methods that repeat mechanism dimension design, simulation, and verification cannot rapidly ensure a suitable result. Optimization methods can obtain an optimal result but cannot be visualized and utilize engineers' valuable experience. This paper proposes a novel mechanism dimension design method for six-legged robots that maximize terrain traversal capabilities in four representative terrains: trenches, low spaces, obstacles, and steps. Analytical conditions are established to model the relationship between robot's mechanism dimensions and terrain parameters, which are derived from robot-terrain non-interference conditions, static stabilities, and workspace limitations. Performance charts of the terrain traversal capabilities are plotted to show visualized regions for suitable mechanism dimensions. A suitable dimension is then selected by engineers based on the charts. The resulted design is further validated through simulations and experiments on a physical prototype.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141606042","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

Dynamic models for power transmission monitoring in non-stationary conditions based on IAS signals 基于 IAS 信号的非稳态条件下输电监控动态模型

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-07-11 DOI: 10.1016/j.mechmachtheory.2024.105733

Nathanael THIBAULT , Adeline BOURDON , Didier RÉMOND , Damien LECOUVREUR

{"title":"Dynamic models for power transmission monitoring in non-stationary conditions based on IAS signals","authors":"Nathanael THIBAULT , Adeline BOURDON , Didier RÉMOND , Damien LECOUVREUR","doi":"10.1016/j.mechmachtheory.2024.105733","DOIUrl":"https://doi.org/10.1016/j.mechmachtheory.2024.105733","url":null,"abstract":"<div><p>This paper describes a dynamic model of two stage gear power transmission including shafts, ball and roller bearings as well as spur and helical gears. The fundamental objective of this model is to introduce a simulator of realistic signals for monitoring the dynamic behavior of such transmissions in non-stationary operating conditions. Special attention is paid to the couplings between mechanical components through the shaft rotation. The analyses carried out are mainly based on the Instantaneous Angular Speed (IAS) as an alternative signal to classical vibrations. Simulations have demonstrated the relevance of IAS as a tool for health monitoring of common gear or bearing faults in non-stationary operating conditions. Suggested angular approaches offer the ability to separate excitations from the transfer function of the system. The interactions between bearings and gears appear as modulation sidebands and suggest a new way to use demodulation methods. Finally, the influence and the detectability of damages on both mechanical components (spall on bearings, spall and crack on gears) using the mentioned techniques are discussed, offering new incomes for signal processing tools in gear transmission monitoring.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0094114X24001605/pdfft?md5=8742bb11b647acb773af527b01fd2e3b&pid=1-s2.0-S0094114X24001605-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141593249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A novel multi-pulse friction compensation strategy for hybrid robots 混合动力机器人的新型多脉冲摩擦补偿策略

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-07-11 DOI: 10.1016/j.mechmachtheory.2024.105726

Jiale Han, Hongfei Cheng, Xianlei Shan, Haitao Liu, Juliang Xiao, Tian Huang

{"title":"A novel multi-pulse friction compensation strategy for hybrid robots","authors":"Jiale Han, Hongfei Cheng, Xianlei Shan, Haitao Liu, Juliang Xiao, Tian Huang","doi":"10.1016/j.mechmachtheory.2024.105726","DOIUrl":"https://doi.org/10.1016/j.mechmachtheory.2024.105726","url":null,"abstract":"<div><p>Friction nonlinearity near zero velocity causes substantial tracking errors during joint motion reversals. For hybrid robots, this phenomenon is further influenced by joint acceleration and robot configuration, unique characteristics of hybrid robots that can degrade the performance of traditional friction compensation methods. This paper presents a novel multi-pulse friction compensation strategy that can adapt to joint acceleration and configuration variations in hybrid robots. Bayesian Optimization is employed to automatically tune all compensation parameters. By analyzing experimental data, a potential relationship between compensation parameters and joint acceleration is explored, leading to a concise and effective method for estimating optimal parameters based on joint acceleration. In addition, the basic idea of cluster analysis is combined with a limited number of experiments to achieve online parameter-to-configuration matching. Experimental results on TriMule-200 hybrid robot demonstrate the outstanding performance of this strategy in suppressing tracking errors during velocity reversals, as well as its robustness to joint acceleration and robot configuration variations.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141593248","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 tendon-driven actuator with cantilever initiated variable stiffness used for robotic fingers 用于机器人手指的悬臂式可变刚度腱驱动致动器

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-07-10 DOI: 10.1016/j.mechmachtheory.2024.105730

Chenning Li , Shangkui Yang , David T. Branson , Zhibin Song , Tao Sun , Jian S. Dai , Rongjie Kang

引用次数: 0