Mechanical Sciences最新文献_第10页

A 2 degrees of freedom united propulsive mechanism for amphibious function inspired by frog's hindlimb 受青蛙后肢启发设计的2自由度联合推进机构，用于两栖功能

IF 1.4 4区工程技术

Mechanical Sciences Pub Date : 2022-05-13 DOI: 10.5194/ms-13-437-2022

Yucheng Tang, Xiaolong Yang, Xiaojin Zhu, Shichao Zhou, Wenbin Zha, Yuxin Sun, Yulin Wang

{"title":"A 2 degrees of freedom united propulsive mechanism for amphibious function inspired by frog's hindlimb","authors":"Yucheng Tang, Xiaolong Yang, Xiaojin Zhu, Shichao Zhou, Wenbin Zha, Yuxin Sun, Yulin Wang","doi":"10.5194/ms-13-437-2022","DOIUrl":"https://doi.org/10.5194/ms-13-437-2022","url":null,"abstract":"Abstract. Amphibious species of frogs are notable candidates to\u0000mimic for amphibious robotic design, as their swimming and sprawling locomotion is generated by the united propulsive mechanisms in which the hindlimbs play the dominant role. Although the propulsive system of frogs is not as complex as other amphibians, it is still difficult to employ the\u0000propulsive mechanism in robotic design due to the numerous degrees of freedom (DoF). This paper proposes a novel united propulsive mechanism to acquire the amphibious function inspired by the frog's hindlimb. The mechanism is a hybrid design combining a planar six-bar linkage, which is designed based on homotopy continuation and a spatial four-bar linkage. The DoF of the hindlimb-like mechanism are dramatically decreased to 2, with 1 each in the two sub-chains. Forward analysis is conducted to find the pose of the foot when two actuations are input. The improved analysis based on the geometrical features overcomes the multiplicity from the\u0000numerical computation. The inverse kinematic analysis is conducted to find the rotation of the input with a given pose of the foot. The aquatic function of the united propulsive mechanism is demonstrated based on the blade element theory, where the rotational speed and the projected area of the foot are fully active. The terrestrial function of the propulsive mechanism is validated with a specific gait.\u0000","PeriodicalId":18413,"journal":{"name":"Mechanical Sciences","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47649244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Payload-adaptive iterative learning control for robotic manipulators 机械臂有效载荷自适应迭代学习控制

IF 1.4 4区工程技术

Mechanical Sciences Pub Date : 2022-05-04 DOI: 10.5194/ms-13-427-2022

Kaloyan Yovchev, Lyubomira Miteva

{"title":"Payload-adaptive iterative learning control for robotic manipulators","authors":"Kaloyan Yovchev, Lyubomira Miteva","doi":"10.5194/ms-13-427-2022","DOIUrl":"https://doi.org/10.5194/ms-13-427-2022","url":null,"abstract":"Abstract. The main purpose of the iterative learning control (ILC) method is to reduce the trajectory tracking error caused by an inaccurate model of the\u0000robot's dynamics. It estimates the tracking error and applies a learning operator to the output control signals to correct them. Today's ILC\u0000researchers are suggesting strategies for increasing the ILC's overall performance and minimizing the number of iterations required. When a payload\u0000(or a different end effector) is attached to a robotic manipulator, the dynamics of the robot change. When a new payload is added, even the most\u0000accurately approximated model of the dynamics will be altered. This will necessitate changes to the dynamics estimates, which may be avoided if the ILC\u0000process is used to control the system. When robotic manipulators are considered, this study analyses how the payload affects the dynamics and\u0000proposes ways to improve the ILC process. The study looks at the dynamics of a SCARA-type robot. Its inertia matrix is determined by the payload\u0000attached to it. The results show that the ILC method can correct for the estimated inertia matrix inaccuracy caused by the changing payload but at\u0000the cost of more iterations. Without any additional data of the payload's properties, the suggested technique may adjust and fine-tune the learning\u0000operator. On a preset reference trajectory, the payload adaptation process is empirically tested. When the same payload is mounted, the acquired\u0000adaptation improvements are then utilized for another desired trajectory. A computer simulation is also used to validate the suggested method. The\u0000suggested method increases the overall performance of ILC for industrial robotic manipulators with a set of similar trajectories but different types\u0000of end effectors or payloads.\u0000","PeriodicalId":18413,"journal":{"name":"Mechanical Sciences","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47536873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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: 2

Structural design of multi-body heave wave energy conversion system and analysis of energy efficiency of floating body on water surface 多体升沉波浪能量转换系统结构设计及水面浮体能量效率分析

IF 1.4 4区工程技术

Mechanical Sciences Pub Date : 2022-04-29 DOI: 10.5194/ms-13-411-2022

Dongsheng Cong, Haowen Jing, Ruijun Zhang, Zhongyue Lu, J. Shang, Zirong Luo

{"title":"Structural design of multi-body heave wave energy conversion system and analysis of energy efficiency of floating body on water surface","authors":"Dongsheng Cong, Haowen Jing, Ruijun Zhang, Zhongyue Lu, J. Shang, Zirong Luo","doi":"10.5194/ms-13-411-2022","DOIUrl":"https://doi.org/10.5194/ms-13-411-2022","url":null,"abstract":"Abstract. Due to the defects of the internal structure and energy supply carrier, conventional deep sea unoccupied marine equipment cannot meet the requirements of low power consumption. In this paper, the whole structure of a multi-body heave wave energy conversion system was designed to capture and convert wave energy. The conversion system consists of a floating body, an underwater absorber and a power takeoff system (PTO). The dynamic\u0000model of the energy conversion system and the mathematical model of energy efficiency evaluation were established according to the dynamic analysis. Based on the real service environment in the South China Sea, the energy efficiency characteristics of floating bodies with different shapes were\u0000simulated, and the amplitude response operator (RAO), radiation damping, added mass and Froude–Krylov force of floating bodies with different shapes were compared. Then, the optimal energy efficiency parameters of surface floating body were explored. Finally, the correctness of the conclusion was verified by the energy efficiency test. The results show that, under the limitation of low power consumption and space scale, the energy conversion system of an axisymmetric rotary body with the same sea conditions, same material and the largest scale can significantly improve the conversion efficiency, and the spherical rotary body performs the best, which makes the\u0000unoccupied marine equipment have a broad prospect for development.\u0000","PeriodicalId":18413,"journal":{"name":"Mechanical Sciences","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44940948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 of a transrectal ultrasonic guided prostate low dose rate brachytherapy robot 经直肠超声引导前列腺低剂量率近距离放射治疗机器人的设计

IF 1.4 4区工程技术

Mechanical Sciences Pub Date : 2022-04-29 DOI: 10.5194/ms-13-399-2022

Xuesong Dai, Yongde Zhang, Jingang Jiang, Bing Li, Sihao Zuo

{"title":"Design of a transrectal ultrasonic guided prostate low dose rate brachytherapy robot","authors":"Xuesong Dai, Yongde Zhang, Jingang Jiang, Bing Li, Sihao Zuo","doi":"10.5194/ms-13-399-2022","DOIUrl":"https://doi.org/10.5194/ms-13-399-2022","url":null,"abstract":"Abstract. Transrectal prostate brachytherapy (BT) can effectively treat prostate cancer. During the operation, doctors need to hold the ultrasound probe for repeated adjustments, which makes it difficult to ensure the efficiency, accuracy, and safety of the operation. We designed an 11 DOF (degrees of freedom) active and passive transrectal BT robot, based on the analysis of the transrectal prostate BT process. The posture adjustment module designed,\u0000based on the double parallelogram mechanism, realizes the centering function of the ultrasound probe and performs the kinematic analysis. Based on Simscape Multibody, the working posture and centering effect of the ultrasound probe's different feed distances are simulated. A physical prototype of the transrectal BT robot was developed and measured in experiments. The experimental results indicate that the angle rotation error of the joint is controlled to within 1∘. The rotation range of each joint meets the design requirements. The maximum error of the yaw angle's remote center point motion and pitch angle's remote center point motion are 0.5 and 0.4 mm, respectively, which are less than the deformation that can be\u0000endured in the anus by 6 mm. The simulation and experimental results and the analysis of measurement errors have verified the effectiveness and stability of the transrectal BT robot.\u0000","PeriodicalId":18413,"journal":{"name":"Mechanical Sciences","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49425088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Novel loop tree for the similarity recognition of kinematic chains 一种新的运动链相似度识别环树

IF 1.4 4区工程技术

Mechanical Sciences Pub Date : 2022-04-25 DOI: 10.5194/ms-13-371-2022

Lei Wang, Liang Sun, Rongjiang Cui, Yadan Xu, Gaohong Yu, C. Wu

{"title":"Novel loop tree for the similarity recognition of kinematic chains","authors":"Lei Wang, Liang Sun, Rongjiang Cui, Yadan Xu, Gaohong Yu, C. Wu","doi":"10.5194/ms-13-371-2022","DOIUrl":"https://doi.org/10.5194/ms-13-371-2022","url":null,"abstract":"Abstract. The similarity recognition of kinematic chains (KCs) is\u0000helpful for improving the efficiency of configuration synthesis, which has been paid more and more attention in recent years. The existing recognition methods are divided into the definition method and feature constant method. Among them, the definition method is difficult to adopt in practice because of its long operation time, especially when the number of similar vertices in KCs is large. In this paper, the new concepts of a loop tree (LT) and a loop tree matrix (LTM) have been proposed, which improve the efficiency of similarity recognition. This method is applied on the complete structure\u0000of the following: 8-link with 1 DOF (degree of freedom), 9-link with 2 DOF, 10-link with 1 DOF, 12-link with 1 DOF, 13-link with 2 DOF, 14-link with 3 DOF, 15-link with 4 DOF planar single-joint KCs, and contracted graphs with up to six independent loops. All results are verified by the definition method to prove the good applicability, reliability, and\u0000efficiency of the proposed method. Simultaneously, the application case of the similarity recognition in a mechanism creation is given to provide a reference for an innovative design.\u0000","PeriodicalId":18413,"journal":{"name":"Mechanical Sciences","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48405375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Assessment of force control for surface finishing – an experimental comparison between Universal Robots UR10e and FerRobotics active contact flange 表面精加工力控制的评估——通用机器人UR10e和FerRobotics主动接触法兰的实验比较

IF 1.4 4区工程技术

Mechanical Sciences Pub Date : 2022-04-21 DOI: 10.5194/ms-13-361-2022

Stefan Gadringer, H. Gattringer, A. Mueller

{"title":"Assessment of force control for surface finishing – an experimental comparison between Universal Robots UR10e and FerRobotics active contact flange","authors":"Stefan Gadringer, H. Gattringer, A. Mueller","doi":"10.5194/ms-13-361-2022","DOIUrl":"https://doi.org/10.5194/ms-13-361-2022","url":null,"abstract":"Abstract. Robotic surface treatment is already broadly used in the manufacturing industry because it guarantees repeatable high-quality surfaces at short production time. Such a robotic solution, with an accurate control of the applied force on a surface, requires a robot that is either equipped with a force/torque sensor or, alternatively, with a force compliance device. However, without a direct performance comparison, it is hard to know which is the best option for a specific surface treatment operation. Compared to the evaluation of the robot positioning accuracy, using the ISO 9283 test, no standardized test for the quality assessment of robot force control exists yet. In trying to fill this gap, this paper introduces different test scenarios and a test set-up for such a force control quality assessment. As a start, the force control of a Universal Robots UR10e model and a FerRobotics ACF-K 109/04 model are experimentally evaluated. The latter is an external device with controlled force/compliance characteristics, which is referred to as an active contact flange (ACF). For the performance comparison, an ATI force/torque sensor, which is mounted below a work piece, measures the applied force either by the UR or by the ACF. The measured forces are further transformed to the UR tool centre point (TCP) frame. Then, only the z component of the force, or rather the normal force, is relevant for surface treatment and hence important for the evaluation. For each test case, the average value of five test runs with the same parameters is used for the assessment. Results for both the UR and ACF force control are presented for varying desired contact velocities and desired forces. These results indicate the advantage of the ACF-K 109/04 over the UR10e force control for highly dynamic force control scenarios.\u0000","PeriodicalId":18413,"journal":{"name":"Mechanical Sciences","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41429172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Innovative design method for planar mechanism configuration based on component similarity discrimination 基于部件相似性判别的平面机构构型创新设计方法

IF 1.4 4区工程技术

Mechanical Sciences Pub Date : 2022-04-13 DOI: 10.5194/ms-13-353-2022

Weiwei Hong, Jinxin Chen, Bingliang Ye, Rongjiang Cui

引用次数: 0

Optimal sensor placement and model updating applied to the operational modal analysis of a nonuniform wind turbine tower 传感器优化配置与模型更新应用于非均匀风力发电塔架运行模态分析

IF 1.4 4区工程技术

Mechanical Sciences Pub Date : 2022-04-06 DOI: 10.5194/ms-13-331-2022

Mohammad Tamizifar, M. Mosayebi, S. Ziaei-Rad

{"title":"Optimal sensor placement and model updating applied to the operational modal analysis of a nonuniform wind turbine tower","authors":"Mohammad Tamizifar, M. Mosayebi, S. Ziaei-Rad","doi":"10.5194/ms-13-331-2022","DOIUrl":"https://doi.org/10.5194/ms-13-331-2022","url":null,"abstract":"Abstract. Test planning is a crucial step in the operational modal analysis (OMA) of wind turbines (WT), and it is an essential part of choosing the best positions for installing the sensors of the structures. On the other hand, updating the finite element model (FEM) with the OMA results implies a better prediction of the real structure's dynamic and vibrational behavior. This paper aims to show how the OMA of a nonuniform and two-section wind turbine tower can be performed more effectively, using the required test planning and optimal sensor placement. Then, accordingly, the OMA is used in operating and parked conditions to find the objective bending mode characteristics. Moreover, the updating of the applicable FEM of the multi-sectional wind turbine tower will be described. The tailor-made genetic algorithm (GA) is used to find the MEMS (micro electro-mechanical system) sensors' optimal positions of the WT under study. The OMA was performed and the acquired data analyzed using the stochastic subspace identification (SSI) method. Based on the OMA results, the FEM is updated by applying the sensitivity method. The results show that a tailor-made GA is a practical and quick approach to finding the optimal position of the sensors to obtain the best results for the objective modes of the WT. The OMA results, under operating and parked conditions, prove some modal characteristics of WTs. Based on the sensitivity analysis and engineering judgment, the modulus of elasticity was selected as a parameter for updating. Finally, we found that the updated FEM had less than 1 % error compared to the obtained frequencies from the test.\u0000","PeriodicalId":18413,"journal":{"name":"Mechanical Sciences","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42702389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 divergent bifurcations in the dynamics of wheeled vehicles 轮式车辆动力学中的发散分岔分析

IF 1.4 4区工程技术

Mechanical Sciences Pub Date : 2022-04-04 DOI: 10.5194/ms-13-321-2022

V. Verbitskii, V. Lobas, Yevgen Misko, A. Bondarenko

{"title":"Analysis of divergent bifurcations in the dynamics of wheeled vehicles","authors":"V. Verbitskii, V. Lobas, Yevgen Misko, A. Bondarenko","doi":"10.5194/ms-13-321-2022","DOIUrl":"https://doi.org/10.5194/ms-13-321-2022","url":null,"abstract":"Abstract. This paper presents the bifurcation approach to analyze divergent\u0000loss of stability of the symmetric solution of a nonlinear dynamic model in\u0000Lyapunov's critical case of a single zero root. Under such a condition,\u0000material birth-annihilation bifurcations of multiple stationary states take\u0000place. Moreover, the equilibrium surface of stationary states in a small\u0000neighborhood of the symmetric solution is a generalized Whitney fold. In the\u0000simplest case of a fold peculiarity, the corresponding bifurcation manifold\u0000locally coincides with the discriminant manifold of a third-degree\u0000polynomial that determines the manifold of stationary states in a small\u0000neighborhood of the symmetric solution. An algorithm to construct the corresponding polynomial is introduced.\u0000Through the algorithm, the bifurcation manifold is determined, and the\u0000conditions for safe/unsafe loss of stability of the symmetric solution are\u0000derived analytically. The proposed approach to analyze divergent loss of stability is implemented\u0000for a nonlinear bicycle model of a two-axle wheeled vehicle. It represents\u0000a further development of Pevzner–Pacejka's well-known graph-analytical\u0000method. The paper determines the critical values of constructive parameters\u0000that are responsible for safe/unsafe loss of stability of the vehicle's\u0000straight-line motion, and it discusses strategies for the bifurcation\u0000approach to analyze divergent loss of stability.\u0000","PeriodicalId":18413,"journal":{"name":"Mechanical Sciences","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48418563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Analytical model establishment and attitude calculation of a parallel leaf-spring carrying mechanism 平行板簧承载机构的分析模型建立及姿态计算

IF 1.4 4区工程技术

Mechanical Sciences Pub Date : 2022-04-01 DOI: 10.5194/ms-13-311-2022

P. Li, Z. Tong, Wei-hua Zhang

{"title":"Analytical model establishment and attitude calculation of a parallel leaf-spring carrying mechanism","authors":"P. Li, Z. Tong, Wei-hua Zhang","doi":"10.5194/ms-13-311-2022","DOIUrl":"https://doi.org/10.5194/ms-13-311-2022","url":null,"abstract":"Abstract. In this paper, a novel parallel leaf-spring carrying mechanism (PLCM)\u0000is investigated using a compliance-matrix-based approach.\u0000For the analytical modeling and attitude calculation, the geometric errors of the\u0000flexible arm, including the height and the top plane's direction, are considered, and the\u0000displacement method is used to calculate the equilibrium attitude. The\u0000influence of the equilibrium attitude at different heights and the initial tilts of the\u0000top planes are analyzed separately. The validity and effectiveness of the\u0000attitude calculation are illustrated by experimental verification. The laser\u0000triangulation coordinate method is used for attitude measurement. The\u0000deviations of the normal vector between the calculation results and measurement\u0000results are smaller than 2×10-4, which is small enough to satisfy\u0000practical requirements. This can be used to guarantee stable and accurate\u0000wafer transfer in a lithography machine. Therefore, it can be concluded\u0000that the methods employed for analytical model establishment and attitude\u0000calculation can be used as a reference for the analysis and design of a\u0000complex parallel compliant mechanism.\u0000","PeriodicalId":18413,"journal":{"name":"Mechanical Sciences","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43249889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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: 1