This paper presents a novel bio-syncretic parallel hip exoskeleton (BsPH-Exo) to address the rehabilitation exercise needs of individuals with lower limb motor dysfunction. BsPH-Exo has six degrees of freedom and can generate all three kinds of rotations that the hip joint can naturally realize. BsPH-Exo effectively solves the problem of misalignment between human and exoskeleton joints, eliminating the need for patients to perform any alignment operations. Considering the varying maximum torque requirements for hip joint rehabilitation in different directions, the limbs of BsPH-Exo are specially arranged to ensure that the maximum torque provided by BsPH-Exo in each direction follows the same law as that of the required torque. As a result, BsPH-Exo exhibits excellent output torque performance, specifically in the flexion/extension direction. Moreover, BsPH-Exo demonstrates weak coupling characteristics in the flexion/extension direction and decoupling characteristics in the adduction/abduction direction, which reduces the difficulty in its control. Compared to currently available parallel hip exoskeletons, BsPH-Exo has several distinct advantages that make it particularly well-suited for rehabilitation applications.
{"title":"Development and Analysis of a Novel Bio-syncretic Parallel Hip Exoskeleton Based on Torque Requirements","authors":"Jilong Xu, Yunzhan Niu, Fucai Liu","doi":"10.1115/1.4066039","DOIUrl":"https://doi.org/10.1115/1.4066039","url":null,"abstract":"\u0000 This paper presents a novel bio-syncretic parallel hip exoskeleton (BsPH-Exo) to address the rehabilitation exercise needs of individuals with lower limb motor dysfunction. BsPH-Exo has six degrees of freedom and can generate all three kinds of rotations that the hip joint can naturally realize. BsPH-Exo effectively solves the problem of misalignment between human and exoskeleton joints, eliminating the need for patients to perform any alignment operations. Considering the varying maximum torque requirements for hip joint rehabilitation in different directions, the limbs of BsPH-Exo are specially arranged to ensure that the maximum torque provided by BsPH-Exo in each direction follows the same law as that of the required torque. As a result, BsPH-Exo exhibits excellent output torque performance, specifically in the flexion/extension direction. Moreover, BsPH-Exo demonstrates weak coupling characteristics in the flexion/extension direction and decoupling characteristics in the adduction/abduction direction, which reduces the difficulty in its control. Compared to currently available parallel hip exoskeletons, BsPH-Exo has several distinct advantages that make it particularly well-suited for rehabilitation applications.","PeriodicalId":508172,"journal":{"name":"Journal of Mechanisms and Robotics","volume":"29 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141813147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Head-following (tracking) issue is a challenge in developing multi-joint continuum robots. However various approaches have been developed in head-following algorithm for articulated-driven mechanism (ADM) continuum robots, problems still exist such as low end-accuracy, large trajectory deviation, and low computational efficiency. This paper presents a novel head-following algorithm(NHF) with high precision, small trajectory deviation, and high computational efficiency for multi-joint ADM continuum robots. The proposed algorithm first uses the follow-the-leader (FTL) method to search for planning points. Secondly, the end-effector errors are calculated, split, and adjusted. Thirdly, the error judgment set is assigned based on the error rate of the end-effector, and also the joints that need to be adjusted are determined. Finally, the joint angles are iteratively adjusted. In this paper, the NHF algorithm is simulated on ADM continuum robots with saparately 10, 20 and 31 joints. The result shows that, compareing with other FTL algorithms, NHF algorithm has the highest end accuracy, and the smallest trajectory deviation.
{"title":"A Novel Head-following Algorithm for Multi-Joint Articulated Driven Continuum Robots","authors":"Jianyu Yang, Xuanting Li, Zhongqi Sheng, Xiaofeng Ma, Hui Shi, Hualong Xie","doi":"10.1115/1.4066000","DOIUrl":"https://doi.org/10.1115/1.4066000","url":null,"abstract":"\u0000 Head-following (tracking) issue is a challenge in developing multi-joint continuum robots. However various approaches have been developed in head-following algorithm for articulated-driven mechanism (ADM) continuum robots, problems still exist such as low end-accuracy, large trajectory deviation, and low computational efficiency. This paper presents a novel head-following algorithm(NHF) with high precision, small trajectory deviation, and high computational efficiency for multi-joint ADM continuum robots. The proposed algorithm first uses the follow-the-leader (FTL) method to search for planning points. Secondly, the end-effector errors are calculated, split, and adjusted. Thirdly, the error judgment set is assigned based on the error rate of the end-effector, and also the joints that need to be adjusted are determined. Finally, the joint angles are iteratively adjusted. In this paper, the NHF algorithm is simulated on ADM continuum robots with saparately 10, 20 and 31 joints. The result shows that, compareing with other FTL algorithms, NHF algorithm has the highest end accuracy, and the smallest trajectory deviation.","PeriodicalId":508172,"journal":{"name":"Journal of Mechanisms and Robotics","volume":"2 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141640494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alizée Koszulinski, Juan Sebastian Sandoval Arevalo, M. Arsicault, M. Laribi
This paper deals with the development of a 6-degrees-of-freedom (DoF) hybrid interface for a teleoperated robotic platform intended to assist surgeons in cervical spine surgery. The targeted task is the drilling of cervical vertebrae for the attachment of spinal implants. Given the complex anatomy of the cervical region, with the proximity of the spinal cord and vertebral arteries, high accuracy in the drilling procedure is required to avoid complications for the patient. In this context, the proposed hybrid interface has been designed to meet the requirements of the drilling task, in terms of degrees of freedom, workspace and force feedback, which have been identified through a literature review. It consists of an association of two parallel mechanisms and a centrally located serial mechanism. Direct and inverse kinematic modelling of each mechanism as well as the one of the complete interface were carried out. A study of the dexterity distribution of the parallel mechanisms was carried out in order to select the suitable interface working mode that would keep the singularities away from the prescribed workspace. In addition, the force feedback was implemented in static mode, neglecting in a first time the weight of the system. The interface design parameters were then optimized to avoid singularities within the prescribed workspace, to minimize motor torques, and to reduce the size of the interface. These development stages led to the design of a motorized prototype of the hybrid interface.
{"title":"Development of a 6 degrees- of-freedom hybrid interface intended for teleoperated robotic cervical spine surgery","authors":"Alizée Koszulinski, Juan Sebastian Sandoval Arevalo, M. Arsicault, M. Laribi","doi":"10.1115/1.4065917","DOIUrl":"https://doi.org/10.1115/1.4065917","url":null,"abstract":"\u0000 This paper deals with the development of a 6-degrees-of-freedom (DoF) hybrid interface for a teleoperated robotic platform intended to assist surgeons in cervical spine surgery. The targeted task is the drilling of cervical vertebrae for the attachment of spinal implants. Given the complex anatomy of the cervical region, with the proximity of the spinal cord and vertebral arteries, high accuracy in the drilling procedure is required to avoid complications for the patient. In this context, the proposed hybrid interface has been designed to meet the requirements of the drilling task, in terms of degrees of freedom, workspace and force feedback, which have been identified through a literature review. It consists of an association of two parallel mechanisms and a centrally located serial mechanism. Direct and inverse kinematic modelling of each mechanism as well as the one of the complete interface were carried out. A study of the dexterity distribution of the parallel mechanisms was carried out in order to select the suitable interface working mode that would keep the singularities away from the prescribed workspace. In addition, the force feedback was implemented in static mode, neglecting in a first time the weight of the system. The interface design parameters were then optimized to avoid singularities within the prescribed workspace, to minimize motor torques, and to reduce the size of the interface. These development stages led to the design of a motorized prototype of the hybrid interface.","PeriodicalId":508172,"journal":{"name":"Journal of Mechanisms and Robotics","volume":"2 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141661592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chengleng Han, Xu Lin, Mohamed A. A. Abdelkareem, Jia Mi
This study investigates a novel design of a reconfigurable closed-chain leg for hexapod robot with enhanced terrain adaptability. A length adjustable hydraulic cylinder is incorporated into the Theo Jansen linkage in the proposed reconfigurable closed-chain leg, allowing for flexible trajectory by adjusting the length of the hydraulic cylinder. Kinematic model and system dynamics are analyzed considering the multi-body dynamics of the proposed system. To actively adapt to different terrains with flexible footprints, a variable-domain sliding mode control strategy to adjust the length of hydraulic cylinder is investigated and compared with other control strategies. Meanwhile, an active compliant control strategy of the driving motor is analyzed and deployed to improve the stability and compliance during walking. A prototype was fabricated and tested under various configurations. Results demonstrate that the variable-domain sliding mode control algorithm exhibits fast convergence, robustness, and smooth signals for hydraulic cylinder. In addition, the proposed active compliant control strategy of the driving motor can reduce the impact force and ensure stable equilibrium during walking. Therefore, the proposed reconfigurable closed-chain leg can enhance the terrain adaptability and enrich the applications of closed-chain legged robots.
{"title":"Improving Terrain Adaptability and Compliance in Closed-Chain Leg: Design, Control, and Testing","authors":"Chengleng Han, Xu Lin, Mohamed A. A. Abdelkareem, Jia Mi","doi":"10.1115/1.4065891","DOIUrl":"https://doi.org/10.1115/1.4065891","url":null,"abstract":"\u0000 This study investigates a novel design of a reconfigurable closed-chain leg for hexapod robot with enhanced terrain adaptability. A length adjustable hydraulic cylinder is incorporated into the Theo Jansen linkage in the proposed reconfigurable closed-chain leg, allowing for flexible trajectory by adjusting the length of the hydraulic cylinder. Kinematic model and system dynamics are analyzed considering the multi-body dynamics of the proposed system. To actively adapt to different terrains with flexible footprints, a variable-domain sliding mode control strategy to adjust the length of hydraulic cylinder is investigated and compared with other control strategies. Meanwhile, an active compliant control strategy of the driving motor is analyzed and deployed to improve the stability and compliance during walking. A prototype was fabricated and tested under various configurations. Results demonstrate that the variable-domain sliding mode control algorithm exhibits fast convergence, robustness, and smooth signals for hydraulic cylinder. In addition, the proposed active compliant control strategy of the driving motor can reduce the impact force and ensure stable equilibrium during walking. Therefore, the proposed reconfigurable closed-chain leg can enhance the terrain adaptability and enrich the applications of closed-chain legged robots.","PeriodicalId":508172,"journal":{"name":"Journal of Mechanisms and Robotics","volume":"15 S3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141837842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abdelhamid Ghoul, S. Djeffal, Hao Wang, Kamel Kara, M. Hadjili
This paper tackles the challenges encountered in surgical continuum robotics by introducing a dynamic model tailored for a cable-driven continuum robot. The intricacies of dynamic modeling and control frequently lead to suboptimal outcomes. Prior studies have often lacked comprehensive descriptions of individual robot component movements, thereby impeding control processes, especially in the presence of external disturbances. Although machine learning-based models show promise across different domains, they face hurdles in continuum robotics due to the complexity of the systems involved. Traditional mathematical models, in contrast, offer explicit equations, providing better interpretability, unlike machine learning models that may struggle with generalization, especially in highly nonlinear systems like continuum robots. The developed model adeptly captures the kinematic and dynamic constraints of various robot segments, serving as the foundation for a robust optimized control strategy. This strategy, which integrates computed torque control and particle swarm optimization (PSO-CTC), enables real-time computation of joint torques based on feedback, ensuring precise and stable task execution even amidst external perturbations. Comparative analysis with an optimized proportional integral derivative (OPID) controller unequivocally demonstrates the superiority of the optimized computed torque controller (OCTC) in settling time, overshoot, and robustness against disturbances. This advancement represents a noteworthy contribution to robotics, with the potential to significantly enhance continuum robot performance in surgical and inspection applications, thereby fostering innovative advancements across various fields.
{"title":"Enhancing Surgical Robotics: A Dynamic Model and Optimized Control Strategy for Cable-Driven Continuum Robots","authors":"Abdelhamid Ghoul, S. Djeffal, Hao Wang, Kamel Kara, M. Hadjili","doi":"10.1115/1.4065698","DOIUrl":"https://doi.org/10.1115/1.4065698","url":null,"abstract":"\u0000 This paper tackles the challenges encountered in surgical continuum robotics by introducing a dynamic model tailored for a cable-driven continuum robot. The intricacies of dynamic modeling and control frequently lead to suboptimal outcomes. Prior studies have often lacked comprehensive descriptions of individual robot component movements, thereby impeding control processes, especially in the presence of external disturbances. Although machine learning-based models show promise across different domains, they face hurdles in continuum robotics due to the complexity of the systems involved. Traditional mathematical models, in contrast, offer explicit equations, providing better interpretability, unlike machine learning models that may struggle with generalization, especially in highly nonlinear systems like continuum robots. The developed model adeptly captures the kinematic and dynamic constraints of various robot segments, serving as the foundation for a robust optimized control strategy. This strategy, which integrates computed torque control and particle swarm optimization (PSO-CTC), enables real-time computation of joint torques based on feedback, ensuring precise and stable task execution even amidst external perturbations. Comparative analysis with an optimized proportional integral derivative (OPID) controller unequivocally demonstrates the superiority of the optimized computed torque controller (OCTC) in settling time, overshoot, and robustness against disturbances. This advancement represents a noteworthy contribution to robotics, with the potential to significantly enhance continuum robot performance in surgical and inspection applications, thereby fostering innovative advancements across various fields.","PeriodicalId":508172,"journal":{"name":"Journal of Mechanisms and Robotics","volume":"111 17","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141361987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Matteo Caruso, Nicholas Sesto Gorella, P. Gallina, S. Seriani
The present study investigates the problem of towing an object that is lying on a surface in a given workspace and the applicability to a planetary rover with four steering wheels. A quasi-static method has been introduced and used for path planning and for the synthesis of both object and rover trajectories. The rover uses a tether as the towing medium which is modeled as an elastic unilateral constraint. Moreover, a kinematic model of the rover which includes steering asymmetrical joint limits is taken into account. The dynamics model of the overall system is then derived and a sensitivity analysis is performed over a finite number of different trajectories, in order to evaluate the quasi-static assumption, the effects of the model, and the influence of the elastic constraint. Finally, experiments have been performed using the novel Archimede rover prototype and compared with dynamics simulations; the remarkable adherence shown with the model validates the overall approach.
{"title":"Towing an Object With a Rover","authors":"Matteo Caruso, Nicholas Sesto Gorella, P. Gallina, S. Seriani","doi":"10.1115/1.4065697","DOIUrl":"https://doi.org/10.1115/1.4065697","url":null,"abstract":"\u0000 The present study investigates the problem of towing an object that is lying on a surface in a given workspace and the applicability to a planetary rover with four steering wheels. A quasi-static method has been introduced and used for path planning and for the synthesis of both object and rover trajectories. The rover uses a tether as the towing medium which is modeled as an elastic unilateral constraint. Moreover, a kinematic model of the rover which includes steering asymmetrical joint limits is taken into account. The dynamics model of the overall system is then derived and a sensitivity analysis is performed over a finite number of different trajectories, in order to evaluate the quasi-static assumption, the effects of the model, and the influence of the elastic constraint. Finally, experiments have been performed using the novel Archimede rover prototype and compared with dynamics simulations; the remarkable adherence shown with the model validates the overall approach.","PeriodicalId":508172,"journal":{"name":"Journal of Mechanisms and Robotics","volume":" 20","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141366139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This document contains errata for the research paper titled Static Stability of Planar Contacting Systems: Analytical Treatment in Euclidean Space by the same authors. The reasonings are provided along with the corrections. It is evident from the points mentioned below that none of the corrections affect the main contribution of the paper, which is an exact analytical formulation in Euclidean space for studying the static stability of planar rigid systems held by one or more frictional and frictionless contacts under gravity. The authors request the journal editor to allow incorporation of the following corrections for the sake of the reader's understanding and clarity.
{"title":"Errata: Static Stability of Planar Contacting Systems: Analytical Treatment in Euclidean Space. ASME J. Mech. Rob., 16(8): p. 081009; DOI:10.1115/1.4064065","authors":"A. Dan, Rama Krishna K, Subir Kumar Saha","doi":"10.1115/1.4065699","DOIUrl":"https://doi.org/10.1115/1.4065699","url":null,"abstract":"\u0000 This document contains errata for the research paper titled Static Stability of Planar Contacting Systems: Analytical Treatment in Euclidean Space by the same authors. The reasonings are provided along with the corrections. It is evident from the points mentioned below that none of the corrections affect the main contribution of the paper, which is an exact analytical formulation in Euclidean space for studying the static stability of planar rigid systems held by one or more frictional and frictionless contacts under gravity. The authors request the journal editor to allow incorporation of the following corrections for the sake of the reader's understanding and clarity.","PeriodicalId":508172,"journal":{"name":"Journal of Mechanisms and Robotics","volume":"121 34","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141360645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cable-driven parallel robots (CDPRs) are easy to implement modular and reconfigurable design, which effectively meets the requirements of flexible production. To clarify the influence of reconfiguration on the performance of the TBot robot, which is a modular designed high-speed CDPR designed in the preliminary research, analysis method and indexes for the force output and moment constraint performance of CDPRs with co-driven parallel cables are proposed. Influence of typical parameters on the omnidirectional and directional performance of TBot are discussed to provide guidance for reconfiguration. Performances of two typical TBots are compared and analyzed to show the influence of reconfiguration on the performance distribution. The analysis results provide a reconfiguration range for TBot to maintain acceptable omnidirectional performance. And the directional performance remains good with slender base layout.
{"title":"Reconfiguration and Performance Evaluation of TBot Cable-Driven Parallel Robot","authors":"Jinhao Duan, Hanqing Liu, Zhaokun Zhang, Zhufeng Shao, Xiangjun Meng, Jingang Lv, Minjian Huang","doi":"10.1115/1.4065680","DOIUrl":"https://doi.org/10.1115/1.4065680","url":null,"abstract":"\u0000 Cable-driven parallel robots (CDPRs) are easy to implement modular and reconfigurable design, which effectively meets the requirements of flexible production. To clarify the influence of reconfiguration on the performance of the TBot robot, which is a modular designed high-speed CDPR designed in the preliminary research, analysis method and indexes for the force output and moment constraint performance of CDPRs with co-driven parallel cables are proposed. Influence of typical parameters on the omnidirectional and directional performance of TBot are discussed to provide guidance for reconfiguration. Performances of two typical TBots are compared and analyzed to show the influence of reconfiguration on the performance distribution. The analysis results provide a reconfiguration range for TBot to maintain acceptable omnidirectional performance. And the directional performance remains good with slender base layout.","PeriodicalId":508172,"journal":{"name":"Journal of Mechanisms and Robotics","volume":"81 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141385361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Huiping Shen, Yao Tang, Marco Ceccarelli, Ju Li, Tao Li, Hongbo He
Two-limb parallel mechanisms (PMs) can have several advantages, such as avoidance of mechanical collision, fairly simple architecture, easy assembly and large workspace. The paper presents a novel two-limb 3-Degree of freedom (DOF) PMs with two translations and one rotation (2T1R), that are actuated by two sliders. The manipulator runs with decoupled position and orientation with forward position solution without parasitic motions. The main topological characteristics of the PM such as position and orientation characteristic (POC), DOF and coupling degree are analyzed. Secondly, using the kinematic modeling method based on topological characteristics, the unified symbolic forward and inverse position solutions of the two configurations of the PM(I and II) are derived together with the workspace, rotational capacity and singularity. Finally, a comparative analysis regarding the kinematics of two configurations (I and II) is carried out to find an optimal design configuration I of a PM for 2T1R motion.
{"title":"Design and analysis of a new non-parasitic parallel mechanism for 2T1R motion","authors":"Huiping Shen, Yao Tang, Marco Ceccarelli, Ju Li, Tao Li, Hongbo He","doi":"10.1115/1.4065678","DOIUrl":"https://doi.org/10.1115/1.4065678","url":null,"abstract":"\u0000 Two-limb parallel mechanisms (PMs) can have several advantages, such as avoidance of mechanical collision, fairly simple architecture, easy assembly and large workspace. The paper presents a novel two-limb 3-Degree of freedom (DOF) PMs with two translations and one rotation (2T1R), that are actuated by two sliders. The manipulator runs with decoupled position and orientation with forward position solution without parasitic motions. The main topological characteristics of the PM such as position and orientation characteristic (POC), DOF and coupling degree are analyzed. Secondly, using the kinematic modeling method based on topological characteristics, the unified symbolic forward and inverse position solutions of the two configurations of the PM(I and II) are derived together with the workspace, rotational capacity and singularity. Finally, a comparative analysis regarding the kinematics of two configurations (I and II) is carried out to find an optimal design configuration I of a PM for 2T1R motion.","PeriodicalId":508172,"journal":{"name":"Journal of Mechanisms and Robotics","volume":"81 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141268425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The 6-prismatic-spherical-universal (6-PSU) parallel robot is useful for high-accuracy positioning, where the motors are installed on the robot base and the moving parts of the robot have low inertia. A highly accurate kinematic model of the robot is fundamental for the control. The joint clearances of all limbs often exist and have a significant influence on kinematic model accuracy. In this study, an actuation acceleration information based kinematic modeling and identification method for a 6-PSU parallel robot with joint clearances is proposed. The direction of the joint clearance is related to the direction of the force acted on the joint, which is determined by the acceleration of the prismatic actuator. The existence of joint clearances is equivalent to the link length change. The joint clearances are identified from the experiments and compensated. Simulations and experiments show that the proposed method is effective and improves the accuracy of the kinematic model.
{"title":"An Actuation Acceleration based Kinematic Modeling and Parameter Identification Approach for a six-DOF 6-PSU Parallel Robot with Joint Clearances","authors":"Xin Liu, Chenkun Qi, Jianfeng Lin, Dongjin Li, Feng Gao","doi":"10.1115/1.4065679","DOIUrl":"https://doi.org/10.1115/1.4065679","url":null,"abstract":"\u0000 The 6-prismatic-spherical-universal (6-PSU) parallel robot is useful for high-accuracy positioning, where the motors are installed on the robot base and the moving parts of the robot have low inertia. A highly accurate kinematic model of the robot is fundamental for the control. The joint clearances of all limbs often exist and have a significant influence on kinematic model accuracy. In this study, an actuation acceleration information based kinematic modeling and identification method for a 6-PSU parallel robot with joint clearances is proposed. The direction of the joint clearance is related to the direction of the force acted on the joint, which is determined by the acceleration of the prismatic actuator. The existence of joint clearances is equivalent to the link length change. The joint clearances are identified from the experiments and compensated. Simulations and experiments show that the proposed method is effective and improves the accuracy of the kinematic model.","PeriodicalId":508172,"journal":{"name":"Journal of Mechanisms and Robotics","volume":"3 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141265813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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