Mechanism and Machine Theory最新文献_第10页

Horizon-stability control for wheel-legged robot driving over unknow, rough terrain

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-12-14 DOI: 10.1016/j.mechmachtheory.2024.105887

Kang Xu , Shoukun Wang , Lei Shi , Jianyong Li , Binkai Yue

{"title":"Horizon-stability control for wheel-legged robot driving over unknow, rough terrain","authors":"Kang Xu , Shoukun Wang , Lei Shi , Jianyong Li , Binkai Yue","doi":"10.1016/j.mechmachtheory.2024.105887","DOIUrl":"10.1016/j.mechmachtheory.2024.105887","url":null,"abstract":"<div><div>Maintaining the horizontal and stable posture of a robot while traversing unfamiliar, rugged terrain poses a significant challenge in various applications such as wounded rescue and disability assistance. This paper introduces a horizontal-stability control framework designed for a wheel-legged hybrid robot to ensure the stability and horizontal orientation of the robot's trunk when encountering unknown and rough terrain conditions. This framework primarily comprises a compliance controller and a terrain adaptation controller. The compliance controller is geared towards establishing compliant interactions with the terrain and tracking the desired ground reaction forces. This is achieved through the implementation of a novel adaptive impedance control method to uphold torque equilibrium in the robot's trunk. To conform to the variable terrain, the terrain adaptation controller is employed. This controller decouples posture adjustments and regulates control outputs to adapt to terrains featuring unknown topographical changes. A series of numerical simulations and experimental trials are carried out to validate the proposed methods on a wheel-legged hybrid robot, followed by comparative evaluations to assess its performance.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"205 ","pages":"Article 105887"},"PeriodicalIF":4.5,"publicationDate":"2024-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166262","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

Applications of dynamics metamodels of an eccentric crank-slider mechanism in the initial phase of their design

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-12-13 DOI: 10.1016/j.mechmachtheory.2024.105886

Andrzej Urbaś, Jacek Stadnicki

引用次数: 0

NURBS curve interpolation strategy for smooth motion of industrial robots

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-12-13 DOI: 10.1016/j.mechmachtheory.2024.105885

Yonghao Guo, Wentie Niu, Hongda Liu, Zengao Zhang, Hao Zheng

{"title":"NURBS curve interpolation strategy for smooth motion of industrial robots","authors":"Yonghao Guo, Wentie Niu, Hongda Liu, Zengao Zhang, Hao Zheng","doi":"10.1016/j.mechmachtheory.2024.105885","DOIUrl":"10.1016/j.mechmachtheory.2024.105885","url":null,"abstract":"<div><div>Smooth motion is crucial for industrial robots to efficiently execute accurate path tracking tasks. This paper proposes a NURBS curve interpolation strategy for smooth motion of industrial robots to reduce roughness and contour error. The strategy ensures smooth motion through two stages: feedrate planning and interpolation point parameter calculation. During the feedrate planning stage, kinematics and dynamics constraints, including torque and torque change rate, are considered in the parameter domain. Round-off error is considered, and an S-curve feedrate planning approach is employed to ensure the planned feedrate is smooth after transitioning from the parameter domain to the time domain. In the interpolation point parameter calculation stage, the displacement guidance curve is generated and updated based on the current situation. Interpolation point iteration compensation is conducted to ensure the interpolation output feedrate is smooth. Simulations and experiments are conducted to validate the effectiveness of the proposed strategy. The simulation results indicate that the proposed strategy effectively smooths the interpolation output feedrate while maintaining efficiency. The experimental results show that the strategy effectively reduces roughness and contour error.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"205 ","pages":"Article 105885"},"PeriodicalIF":4.5,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166260","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

Redefining ball screw kinematics: Analysing the limitations of traditional formulations for orbital and angular speed

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-12-13 DOI: 10.1016/j.mechmachtheory.2024.105882

Pello Alberdi, Aitor Arana, Aitor Oyanguren, Jon Larrañaga, Ibai Ulacia

{"title":"Redefining ball screw kinematics: Analysing the limitations of traditional formulations for orbital and angular speed","authors":"Pello Alberdi, Aitor Arana, Aitor Oyanguren, Jon Larrañaga, Ibai Ulacia","doi":"10.1016/j.mechmachtheory.2024.105882","DOIUrl":"10.1016/j.mechmachtheory.2024.105882","url":null,"abstract":"<div><div>The orbital and angular speeds of the balls are fundamental kinematic variables for predicting the dynamic performance of ball screws, including power losses, vibration analysis, ball passing frequency, and wear phenomena. However, the theoretical formulation employed in the literature to calculate these variables does not account for the effect of transversal velocity component introduced by the helix angle. The present work introduces a new formulation that fully incorporates this effect, demonstrating substantial differences between the two approaches, especially at high helix angles. Additionally, a novel experimental methodology is presented to measure the orbital speed by calculating the ratio between the orbital rotation of the ball and the angular displacement of the screw. The experimental results show strong agreement with the predictions of the proposed formulation, offering more accurate results than existing models in the literature. A detailed analysis of the error is conducted, comparing the proposed formulation with traditional literature models across various ball screw geometries. Finally, an analysis of the rolling and sliding state of the contact on the kinematics of the ball is conducted, by studying the impact of the slide-to-roll ratio.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"205 ","pages":"Article 105882"},"PeriodicalIF":4.5,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166315","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

Improving the in-plane bearing stiffness in folded beam diaphragm flexures

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-12-12 DOI: 10.1016/j.mechmachtheory.2024.105883

Moeen Radgolchin , Shorya Awtar , Ruiyu Bai , Guimin Chen

{"title":"Improving the in-plane bearing stiffness in folded beam diaphragm flexures","authors":"Moeen Radgolchin , Shorya Awtar , Ruiyu Bai , Guimin Chen","doi":"10.1016/j.mechmachtheory.2024.105883","DOIUrl":"10.1016/j.mechmachtheory.2024.105883","url":null,"abstract":"<div><div>Diaphragm flexures are commonly used to generate precise out-of-plane motion while providing in-plane load bearing in various precision applications. The basic diaphragm flexure exhibits a parasitic rotation about the out-of-plane direction. While this rotational error motion can be eliminated by the use of folded beams in diaphragm flexures, the unsupported end of the folded beams leads to an elastokinematic drop in the in-plane stiffness with increasing out-of-plane displacement. In this paper, a novel sandwich design for folded beam diaphragm flexures is proposed that significantly improves this in-plane stiffness drop by mitigating the under-constraint of the unsupported ends of the folded beams. The superior performance of the sandwich design is demonstrated via non-linear Finite Element Analysis (FEA) and explained by several design insights derived from closed-form analysis. Six different diaphragm flexures including asymmetric simple beam, asymmetric folded beam, symmetric folded beam, and their sandwich versions, are investigated and categorized according to their out-of-plane stiffness, in-plane stiffness, and parasitic rotation performance. Several design guidelines are proposed to select the appropriate design based on the specific requirements of the diaphragm flexure's intended application.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"205 ","pages":"Article 105883"},"PeriodicalIF":4.5,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165142","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

Discussion on: Jia Ma, Menghao Bai, Jie Wang, Shuai Dong, Hao Jie, Bo Hu, Lairong Yin, “A novel variable restitution coefficient model for sphere–substrate elastoplastic contact/impact process,” Mechanism and Machine Theory 202 (2024)

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-12-12 DOI: 10.1016/j.mechmachtheory.2024.105868

Itzhak Green

引用次数: 0

Double-level reconfigurable variation of Bennett-induced 8R mechanism and its evolved metamorphic 7R mechanism family

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-12-11 DOI: 10.1016/j.mechmachtheory.2024.105879

Xi Kang , Qia Lin , Huijuan Feng , Bing Li

{"title":"Double-level reconfigurable variation of Bennett-induced 8R mechanism and its evolved metamorphic 7R mechanism family","authors":"Xi Kang , Qia Lin , Huijuan Feng , Bing Li","doi":"10.1016/j.mechmachtheory.2024.105879","DOIUrl":"10.1016/j.mechmachtheory.2024.105879","url":null,"abstract":"<div><div>Reconfigurable mechanisms are widely utilized in the design of intelligent robots and devices capable of adapting to diverse environments and requirements. While the design of reconfigurable mechanisms has garnered significant attention, previous studies have primarily focused on single types of reconfiguration, limiting the diversity and potential applications of such mechanisms. This paper introduces a double-level reconfigurable variation that integrates two reconfiguration approaches: joint rigidization and geometric constraints. This variation is derived from an 8R mechanism created by adding four joints to an equilateral Bennett mechanism. The original 8R mechanism serves as a foundation for generating a family of metamorphic mechanisms, including four distinct 7R mechanisms, through selective joint rigidization. Each of these 7R mechanisms exhibits multiple motion branches and singular configurations, which are analyzed in detail, with their metamorphic motion cycles illustrated graphically. In total, the mechanism family encompasses 39 unique motion branches. Some of these branches and singular configurations overlap, enabling transitions between mechanisms by altering rigidization patterns, thereby achieving a double-level reconfigurable variation. This study elucidates the interrelationships among the metamorphic mechanisms within this family, offering valuable insights for advancing the configuration synthesis and application of metamorphic mechanisms.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"205 ","pages":"Article 105879"},"PeriodicalIF":4.5,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166253","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

Meshing theory of point-contact conical-envelope cylindrical worm-face worm gear drive

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-12-07 DOI: 10.1016/j.mechmachtheory.2024.105870

Shibo Mu , Xingwei Sun , Zhixu Dong , Heran Yang , Yin Liu , Weifeng Zhang , Qingxiang Meng , Yaping Zhao

{"title":"Meshing theory of point-contact conical-envelope cylindrical worm-face worm gear drive","authors":"Shibo Mu , Xingwei Sun , Zhixu Dong , Heran Yang , Yin Liu , Weifeng Zhang , Qingxiang Meng , Yaping Zhao","doi":"10.1016/j.mechmachtheory.2024.105870","DOIUrl":"10.1016/j.mechmachtheory.2024.105870","url":null,"abstract":"<div><div>This paper proposes further developing mismatched modification technology in meshing theory via physics-informed neural networks (PINNs). Thus, a design approach that considers meshing performance and meshing theory is presented for the mismatched parameters. On this basis, an innovative point-contact face worm gear drive with symmetric benchmark points is developed and its meshing theory is systematically developed. This study addresses high-dimensional nonlinear equation systems in tooth contact analysis (TCA) via PINN technology to convert initial value problems in conventional iterative methods into physical boundary problems. A PINN technique driven by meshing theory and meshing performance is proposed, achieving a coordinated optimization design for multiple mismatched parameters. The accuracy and feasibility of the PINN technique are proven by comparing it with the traditional iterative method. Applying the established meshing theory, TCA and error sensitivity analysis are conducted for the drive. The numerical results demonstrate that the PINN model has excellent accuracy in solving high-dimensional nonlinear equation systems. The analysis of the meshing characteristics indicates outstanding performance and a reduced susceptibility to installation errors.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"205 ","pages":"Article 105870"},"PeriodicalIF":4.5,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166255","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 modeling and effective vibration reduction of dual-link flexible manipulators with two-stage cascade PID and active torque actuation

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-12-06 DOI: 10.1016/j.mechmachtheory.2024.105867

Nitin Gupta, Barun Pratiher

{"title":"Dynamic modeling and effective vibration reduction of dual-link flexible manipulators with two-stage cascade PID and active torque actuation","authors":"Nitin Gupta, Barun Pratiher","doi":"10.1016/j.mechmachtheory.2024.105867","DOIUrl":"10.1016/j.mechmachtheory.2024.105867","url":null,"abstract":"<div><div>Flexible manipulators, praised for their adaptability, face challenges in controlling inherent vibrations. This study introduces an advanced control strategy that employs active torque actuation to effectively mitigate tip vibrations in a dual-link flexible manipulator, enhancing stability and performance. An accurate dynamic model, developed using extended Hamilton’s principle and the assumed mode method, addresses the system’s natural frequencies and mode shapes, transforming coupled nonlinear partial differential equations into simpler ordinary differential equations with defined boundary conditions. The robust control strategy employs a two-stage cascade Proportional–Integral–Derivative (PID) controller, managing rigid and flexible motions separately to ensure precise control and stability despite the manipulator’s complexities. Analytical and experimental results show that this control strategy significantly improves transient response by reducing settling time and overshooting, with minor changes to peak time. MATLAB simulations and experiments confirm the effective damping of flexible deflections, aligning closely with dynamic model predictions. These results underscore the effectiveness of the control strategy and dynamic model in achieving superior vibration suppression and improved transient response, thereby optimizing system performance.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"205 ","pages":"Article 105867"},"PeriodicalIF":4.5,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166254","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

Effect of redundant rollers in planetary gearbox

IF 4.5 1区工程技术

Mechanism and Machine Theory Pub Date : 2024-12-05 DOI: 10.1016/j.mechmachtheory.2024.105871

Anand Varadharajan , Pablo López García , Stein Crispel , Dirk Lefeber , Tom Verstraten

引用次数: 0