Mechanism and Machine Theory最新文献_第5页

Quasi-static chain drive model for efficiency calculation - Application to track cycling 用于效率计算的准静态链传动模型 - 轨道自行车的应用

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-09-03 DOI: 10.1016/j.mechmachtheory.2024.105780

{"title":"Quasi-static chain drive model for efficiency calculation - Application to track cycling","authors":"","doi":"10.1016/j.mechmachtheory.2024.105780","DOIUrl":"10.1016/j.mechmachtheory.2024.105780","url":null,"abstract":"<div><p>Intense competition between top-level track cycling athletes rEq.uires research to make optimisation possible. In this context, the energetic efficiency of roller chain drives is studied to improve understanding of loss sources and to propose improvements. Losses in chain drives are mainly caused by the meshing/un-meshing process of chain links on the sprockets. However, a preliminary study shows that losses caused by the motion of rollers along their associated tooth profile have a significant influence. The aim of this paper is therefore to explore this phenomenon. An original 2D quasi static model of a two-sprocket drive is presented. The global drive kinematics (including transmission error) is determined using specific sub-models for the tight and slack strands. A local sprocket sub-model is then introduced to calculate link tension, roller/sprocket contact force and roller location. This model can be used for different tooth profile geometries. Based on the results provided by the global and local model, the presented model calculates drive efficiency, considering the losses caused by meshing and roller motion. A comparison with literature is done to ensure the model validity.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0094114X24002076/pdfft?md5=a911b2d5aff7df6105283299c4218147&pid=1-s2.0-S0094114X24002076-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142128441","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

Analysis and design optimization of a compliant robotic gripper mechanism with inverted flexure joints 带有倒置挠性接头的顺应式机器人抓手机构的分析与优化设计

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-09-02 DOI: 10.1016/j.mechmachtheory.2024.105779

{"title":"Analysis and design optimization of a compliant robotic gripper mechanism with inverted flexure joints","authors":"","doi":"10.1016/j.mechmachtheory.2024.105779","DOIUrl":"10.1016/j.mechmachtheory.2024.105779","url":null,"abstract":"<div><p>Flexure-jointed grippers provide compliant grasping capability, have low-cost and flexible manufacturing, and are insusceptible to joint friction and wear. However, their grasp stiffness can be limited by flexure compliance such that loss-of-grasp is prone to occur for high object loads. This paper examines the application of inverted-flexure joints in a cable-driven gripper that can avoid flexure buckling and greatly enhance grasp stiffness and stability. To analyze behavior, an energy-based kinetostatic model is developed for a benchmark grasping problem and validated by hardware experiments. A multi-objective design optimization study is conducted, considering key metrics of peak flexure stress, grasp stiffness, and cable actuation force. Results show that the inverted-flexure design has significantly higher grasp stiffness (63% higher in a targeted design optimization) and requires lower actuation forces (¿20% lower in all optimization cases), compared with equivalent direct-flexure designs. An application study is conducted to validate the predicted operating performance under gravity loading of the grasped object. The results demonstrate that stable and high stiffness grasping can be achieved, even under overload conditions that lead to loss-of-grasp for conventional direct-flexure designs.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142122620","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 novel design method of a nonlinear elastic mechanism for series elastic actuators 串联弹性致动器非线性弹性机构的新型设计方法

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-09-01 DOI: 10.1016/j.mechmachtheory.2024.105775

{"title":"A novel design method of a nonlinear elastic mechanism for series elastic actuators","authors":"","doi":"10.1016/j.mechmachtheory.2024.105775","DOIUrl":"10.1016/j.mechmachtheory.2024.105775","url":null,"abstract":"<div><p>Series elastic actuators with increasing nonlinear stiffness(NlSEA) have promising applications in human-machine interactions for the existence of a nonlinear elastic mechanism that supplies inherent safety and can implement high torque resolution under low load and quick dynamic response under high load. In this study, a novel design method for a nonlinear elastic mechanism that can be applied in NlSEA is proposed. By combining the S-shaped cantilever beam and specialized cam surface, this study proposed an analytical approach to design a nonlinear elastic mechanism satisfying a given stiffening torque-deformation relationship. The geometric parameters constraints were discussed to support parameter determination. Two kinds of cases of nonlinear elastic mechanisms with increasing and constant stiffness characteristics were conducted to verify the effectiveness and generalizability of the proposed design method by simulations. Moreover, a nonlinear elastic mechanism with an increasing stiffness characteristic was designed and a prototype was fabricated. A torque-deformation verification experiment, regulation response experiments, and sinusoidal tracking experiments were conducted to verify the accuracy, response performance, and tracking performance of the prototype. The designed nonlinear elastic mechanism has a large torque-to-mass ratio in a compact and lightweight structure.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142117584","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

Real-time control of a soft manipulator based on reduced order extended position-based dynamics 基于减阶扩展位置动力学的软机械手实时控制

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-08-30 DOI: 10.1016/j.mechmachtheory.2024.105774

{"title":"Real-time control of a soft manipulator based on reduced order extended position-based dynamics","authors":"","doi":"10.1016/j.mechmachtheory.2024.105774","DOIUrl":"10.1016/j.mechmachtheory.2024.105774","url":null,"abstract":"<div><p>Soft robots are high-dimensional nonlinear systems coupled with both geometric and material nonlinearity. Control of such a system is complex and time-consuming. In this study, a real-time trajectory tracking control framework is established based on the reduced order extended position-based dynamics. In contrast to the common nonlinear model order reduction methods that require to collect a large number of data to create the motion subspace, this article's motion subspace is constructed based on the model configuration and material properties. The linear modes of the model and the related modal derivatives provide the reduced order matrix, which streamlines and increases the efficiency of model construction. Then, coupled with the instantaneous optimal control, a real-time reduced order model-based control framework of soft robots can be constructed. Experiments on trajectory tracking of a soft manipulator are conducted to verify the accuracy and efficiency of the proposed controller. The average error of all experiments is within 1 cm; and the single-step calculation time of the controller is about 0.057 s, which is less than the sampling period 0.1 s.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142095195","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

On-board electric powertrain control for the compensation of the longitudinal acceleration oscillations caused by road irregularities 用于补偿路面不平造成的纵向加速度振荡的车载电动动力总成控制装置

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-08-29 DOI: 10.1016/j.mechmachtheory.2024.105759

{"title":"On-board electric powertrain control for the compensation of the longitudinal acceleration oscillations caused by road irregularities","authors":"","doi":"10.1016/j.mechmachtheory.2024.105759","DOIUrl":"10.1016/j.mechmachtheory.2024.105759","url":null,"abstract":"<div><p>Road irregularities affect vehicle comfort by causing vertical and longitudinal acceleration oscillations. While the current ride comfort enhancement solutions are based on the compensation of the vertical acceleration of the sprung mass, the compensation of the longitudinal dynamics excited by road irregularities has been successfully explored only for in-wheel powertrains. The scope of this study is to demonstrate that also on-board electric powertrains with torsional dynamics of the half-shafts have the potential for effective compensation, thanks to the road profile preview. This paper presents a proof-of-concept nonlinear model predictive controller (NMPC) with road preview, which is assessed with a validated simulation model of an all-wheel drive electric vehicle. Three powertrain layouts are considered, with four in-wheel, four on-board, and two on-board electric machines. The control function is evaluated along multiple manoeuvres, through comfort-related key performance indicators (KPIs) that, for the four on-board layout along a road step test at 40 km/h, highlight >80% improvements. Finally, the real-time implementability of the algorithms is demonstrated, and preliminary experiments are conducted on an electric quadricycle prototype, with more than halved oscillations of the relevant variables.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0094114X24001861/pdfft?md5=bad61528704aed0cb166c0e0228b3d1f&pid=1-s2.0-S0094114X24001861-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142095096","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

Expanding the family of plane-symmetric 6R deployable polygon mechanisms by systematically exploring the layout of R-joint axes 通过系统探索 R 关节轴的布局，扩展平面对称 6R 可展开多边形机构系列

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-08-28 DOI: 10.1016/j.mechmachtheory.2024.105768

{"title":"Expanding the family of plane-symmetric 6R deployable polygon mechanisms by systematically exploring the layout of R-joint axes","authors":"","doi":"10.1016/j.mechmachtheory.2024.105768","DOIUrl":"10.1016/j.mechmachtheory.2024.105768","url":null,"abstract":"<div><p>In this paper, the impact of parameter variations on the deployable motion characteristics, mobility, input singularity, and deploying/folding performance of plane-symmetric Bricard mechanisms is studied. Firstly, two classes of revolute pair axes used to construct deployable polygon mechanisms (DGMs) are reviewed, and their value ranges are further refined. Secondly, all possible axes arrangement schemes for plane-symmetric 6R DGMs are presented for the first time. Then, an improved schematic synthesis method is proposed, which can be used to design all plane-symmetric 6R DGMs that belong to the plane-symmetric Bricard mechanisms. Thirdly, the improved design method is applied to create a series of single-degree-of-freedom plane-symmetric 6R DGMs. Then, feasible domain searches are performed, and some of them are prototyped. Subsequently, the input singularity of plane-symmetric 6R DGMs is analyzed. Finally, two deploying/folding performance indices are proposed to evaluate the performance of plane-symmetric 6R DGMs with different fully deployed and fully folded states based on actual application scenarios. This work expands the variety and quantity of DGMs, which will also advance the development of robotics, mechanical metamaterials, and kirigami mechanisms.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142088351","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 general framework for designing compliant deployable mechanisms via geometrically exact beam theory 通过几何精确梁理论设计顺应式可展开机构的总体框架

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-08-27 DOI: 10.1016/j.mechmachtheory.2024.105778

引用次数: 0

A new solution to force analysis including Coulomb friction in mechanism joints 包括库仑摩擦在内的机构连接受力分析新方案

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-08-26 DOI: 10.1016/j.mechmachtheory.2024.105776

引用次数: 0

Kinematic synthesis and mechanism design of a six-bar jumping leg for elastic energy storage and release based on dead points 基于死点的弹性储能和释放的六杆跳跃腿的运动学合成和机构设计

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-08-24 DOI: 10.1016/j.mechmachtheory.2024.105777

{"title":"Kinematic synthesis and mechanism design of a six-bar jumping leg for elastic energy storage and release based on dead points","authors":"","doi":"10.1016/j.mechmachtheory.2024.105777","DOIUrl":"10.1016/j.mechmachtheory.2024.105777","url":null,"abstract":"<div><p>Small jumping robots widely adopt complex catapult mechanisms. This paper presents a novel jumping strategy using dead point instead of traditional catapult mechanisms, achieving efficient energy storage and release without increasing mechanical complexity. Single degree-of-freedom (DOF) planar six-bar linkages are widely used in bionic mechanism design due to their simple control and strong design flexibility. However, their complex configuration and numerous parameters make it challenging to carry out multi-objective and multi-constraint designs. In this paper, a design method of single DOF six-bar linkages based on dead-point constraints is proposed to design a frog-inspired leg mechanism. By enumerating the basic configuration atlas and using a stepwise closed-loop method, initial value screening is completed to improve the efficiency of objective function optimization. The dead-point constraints are simplified with graphical geometric properties. The resulting mechanism satisfies multiple objectives and constraints, including shape, motion posture and trajectory, demonstrating the feasibility of the method. Simulations and experiments confirmed the excellent jumping performance of the 147.1-g prototype, with a jump height of 8.55 times leg length and an energy-storing capacity of 35.39 J/kg.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142058383","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 analysis of a flexible struts V-expander tensegrity robot for navigating pipes 设计和分析用于管道导航的柔性支柱 V 型张拉机器人

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-08-21 DOI: 10.1016/j.mechmachtheory.2024.105757

{"title":"Design and analysis of a flexible struts V-expander tensegrity robot for navigating pipes","authors":"","doi":"10.1016/j.mechmachtheory.2024.105757","DOIUrl":"10.1016/j.mechmachtheory.2024.105757","url":null,"abstract":"<div><p>Tensegrity robots have increasingly attracted attention in recent years. Traditionally, these robots rely on rigid struts and cables to maintain equilibrium configurations. However, the inflexibility inherent in these rigid struts curtails the robot’s capacity for deformation, thereby amplifying structural intricacy and imposing limitations on potential applications, particularly in the realm of pipe inspection. Drawing inspiration from the V-expander tensegrity structure, this paper presents a design, analysis, and validation of a flexible struts tensegrity robot. The integration of flexible struts enables the robot to exhibit a compact structure, passive compliance, and excellent adaptability. Through the actuation of three active cables, the robot exhibits inchworm-like motion capabilities for pipes ranging from 50 mm to 110 mm in diameters. A kinetostatics modeling approach is presented to predict the shapes of flexible struts and control the motion behaviors of the robot. To validate the capabilities of the proposed robot and assess the effectiveness of the kinetostatics model, a prototype was constructed and subjected to a series of experiments. The results demonstrate that the prototype exhibits remarkable shape changeability, mobility, and adaptability, while precisely controlling the contact force.</p></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142020533","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