Abstract To improve the motion accuracy of an XYZ-3RPS hybrid kinematic machine (HKM), a geometric error calibration method via binocular vision measurement is studied. First, to separately calibrate the series kinematic mechanisms (SKMs) and parallel kinematic mechanisms (PKMs), the geometric error identification equations (GEIEs) of the XYZ SKM and 3RPS PKM are derived, respectively. By analyzing the different influence principles of the geometric errors on the position and attitude of the 3RPS PKM, a constraint function is added to the GEIE of the PKM to improve the calculation accuracy. Moreover, the geometric error compensation strategy is based on the structural characteristics of the XYZ-3RPS HKM. In addition, based on the principle of binocular vision measurement, two calibration plates, called dynamic and static calibration plates, are designed as markers to define the coordinate systems, enabling the acquisition of full positions and attitudes. Furthermore, a marker transformation method and an in-situ adjustment method are designed to determine the positions and attitudes of the HKM required for calibration such that the marker is always at the center of the field of view of the camera to improve measurement accuracy. Finally, the effectiveness of the calibration method is verified through prototype experiments.
{"title":"Geometric Error Calibration of <i>XYZ</i>-3RPS Hybrid Kinematic Machine via Binocular Vision","authors":"Xiangyu Guo, Rui Wang, Shisheng Zhong, Yuhao Ge, Lingyu Yue","doi":"10.1115/1.4062465","DOIUrl":"https://doi.org/10.1115/1.4062465","url":null,"abstract":"Abstract To improve the motion accuracy of an XYZ-3RPS hybrid kinematic machine (HKM), a geometric error calibration method via binocular vision measurement is studied. First, to separately calibrate the series kinematic mechanisms (SKMs) and parallel kinematic mechanisms (PKMs), the geometric error identification equations (GEIEs) of the XYZ SKM and 3RPS PKM are derived, respectively. By analyzing the different influence principles of the geometric errors on the position and attitude of the 3RPS PKM, a constraint function is added to the GEIE of the PKM to improve the calculation accuracy. Moreover, the geometric error compensation strategy is based on the structural characteristics of the XYZ-3RPS HKM. In addition, based on the principle of binocular vision measurement, two calibration plates, called dynamic and static calibration plates, are designed as markers to define the coordinate systems, enabling the acquisition of full positions and attitudes. Furthermore, a marker transformation method and an in-situ adjustment method are designed to determine the positions and attitudes of the HKM required for calibration such that the marker is always at the center of the field of view of the camera to improve measurement accuracy. Finally, the effectiveness of the calibration method is verified through prototype experiments.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135657269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With the development of minimally invasive surgery (MIS) technology, higher requirements are put forward for the performance of remote center of motion (RCM) manipulator. This paper presents the conceptual design of a novel two degrees of freedom (2-DOF) spherical RCM mechanism, whose axes of all revote joints share the same RCM. Compared with the existing design, the proposed mechanism indicates a compact design and high structure stability, and the same scissor-like linkage makes it easy to realize modular design. It also has the advantages of singularity free and motion decoupling in its workspace, which simplifies the implementation and control of the manipulator. In addition, compared with the traditional spherical scissor linkage mechanism, the proposed mechanism adds a rotation constraint on the output shaft to provide better operating performance. In this paper, the kinematics and singularities of different cases are deduced and compared, and the kinematic model of the best case is established. According to the workspace and constraints in MIS, the optimal structural parameters of the mechanism are determined by dimensional synthesis with the goal of optimal global operation performance. Furthermore, a prototype is assembled to verify the performance of the proposed mechanism. The experimental results show that the 2-DOF prototype can provide a reliable RCM point. The compact design makes the manipulator have potential application prospects in MIS.
{"title":"Design, Dimensional Synthesis and Evaluation of a Novel 2-DOF Spherical RCM Mechanism for Minimally Invasive Surgery","authors":"Jianmin Li, Jiatong Wang, Jianchang Zhao, G. Wei","doi":"10.1115/1.4062673","DOIUrl":"https://doi.org/10.1115/1.4062673","url":null,"abstract":"\u0000 With the development of minimally invasive surgery (MIS) technology, higher requirements are put forward for the performance of remote center of motion (RCM) manipulator. This paper presents the conceptual design of a novel two degrees of freedom (2-DOF) spherical RCM mechanism, whose axes of all revote joints share the same RCM. Compared with the existing design, the proposed mechanism indicates a compact design and high structure stability, and the same scissor-like linkage makes it easy to realize modular design. It also has the advantages of singularity free and motion decoupling in its workspace, which simplifies the implementation and control of the manipulator. In addition, compared with the traditional spherical scissor linkage mechanism, the proposed mechanism adds a rotation constraint on the output shaft to provide better operating performance. In this paper, the kinematics and singularities of different cases are deduced and compared, and the kinematic model of the best case is established. According to the workspace and constraints in MIS, the optimal structural parameters of the mechanism are determined by dimensional synthesis with the goal of optimal global operation performance. Furthermore, a prototype is assembled to verify the performance of the proposed mechanism. The experimental results show that the 2-DOF prototype can provide a reliable RCM point. The compact design makes the manipulator have potential application prospects in MIS.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42388325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Krovi, Guangbo Hao, Guimin Chen, D. Gan, Abbas Fattah, Carl Nelson
This special issue of the ASME Journal of Mechanisms and Robotics (JMR) draws on papers presented at the 46th Mechanisms and Robotics Conference (MR), held as part of the 2022 International Design and Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC/CIE 2022), held in St. Louis, Missouri, August 14-17, 2022.
{"title":"Special Issue: Selected Papers from IDETC-CIE 2022","authors":"V. Krovi, Guangbo Hao, Guimin Chen, D. Gan, Abbas Fattah, Carl Nelson","doi":"10.1115/1.4062671","DOIUrl":"https://doi.org/10.1115/1.4062671","url":null,"abstract":"\u0000 This special issue of the ASME Journal of Mechanisms and Robotics (JMR) draws on papers presented at the 46th Mechanisms and Robotics Conference (MR), held as part of the 2022 International Design and Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC/CIE 2022), held in St. Louis, Missouri, August 14-17, 2022.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43885608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Baran Alikoc, Vojtech Sustr, Filip Žitek, Pavel Burget, A. Lomakin
This paper deals with motion modelling of a 5-axis industrial Delta robot. The robot has extra rotational 2-DoF realised with a wrist arm driven through two co-axial telescopic shafts as compared to the basic 3-DoF Delta robot. The kinematic model is derived with fully symbolic Jacobian matrices. Using the derived Jacobians, a novel simplified dynamic model is proposed based on the virtual work principle and the trajectory dependent artificial mass distribution. As compared to the existing literature, the proposed dynamic model does not require Lagrangian multiplier calculation or recursive and parallel computing so that it provides advantage for model-based control design. Also a linear regression model is provided to identify the dynamic parameters. The presented models are suitable to be employed for basic Delta and the extended Delta robots with parallel telescopic shafts as well. The derived models are verified through a Simulink model where the 3D CAD files of robot bodies having the information of real dimensions, masses and moments of inertia are used. The adequate agreement of the proposed dynamic model with the simulation results are illustrated via performing three different generated trajectory profiles. We also demonstrate the better accuracy of the proposed dynamic model as compared to a simplified and widely-employed model for basic Delta robot. The simulation model is shared online to serve as a research and test platform for performing tasks such as motion planning, model prototyping and control design.
{"title":"Motion Modelling of a 5-Axis Delta Robot with Telescopic Shafts","authors":"Baran Alikoc, Vojtech Sustr, Filip Žitek, Pavel Burget, A. Lomakin","doi":"10.1115/1.4062672","DOIUrl":"https://doi.org/10.1115/1.4062672","url":null,"abstract":"\u0000 This paper deals with motion modelling of a 5-axis industrial Delta robot. The robot has extra rotational 2-DoF realised with a wrist arm driven through two co-axial telescopic shafts as compared to the basic 3-DoF Delta robot. The kinematic model is derived with fully symbolic Jacobian matrices. Using the derived Jacobians, a novel simplified dynamic model is proposed based on the virtual work principle and the trajectory dependent artificial mass distribution. As compared to the existing literature, the proposed dynamic model does not require Lagrangian multiplier calculation or recursive and parallel computing so that it provides advantage for model-based control design. Also a linear regression model is provided to identify the dynamic parameters. The presented models are suitable to be employed for basic Delta and the extended Delta robots with parallel telescopic shafts as well. The derived models are verified through a Simulink model where the 3D CAD files of robot bodies having the information of real dimensions, masses and moments of inertia are used. The adequate agreement of the proposed dynamic model with the simulation results are illustrated via performing three different generated trajectory profiles. We also demonstrate the better accuracy of the proposed dynamic model as compared to a simplified and widely-employed model for basic Delta robot. The simulation model is shared online to serve as a research and test platform for performing tasks such as motion planning, model prototyping and control design.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45838471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Large workpieces are important components of core equipment in aerospace and other fields, where the machining mainly focuses on the surfaces and inner cavities. However, there are no machining robots that can not only achieve high-precision surface machining, but also perform the machining of different inner cavities in a limited space. To fill this gap, a new reconfigurable hybrid robot (RHR) is proposed, called the 3PRR-3PSS-UPU RHR, for machining the surface and inner cavity of large workpieces (where P, P, R, S, and U stand for the actuated prismatic joint, passive prismatic joint, revolute joint, spherical joint, and universal joint, respectively). The proposed RHR consists of two parallel manipulators (PMs), in which one is a spatial 3PRR PM with one translational degree of freedom (DOF) and the other is a 3PSS-UPU reconfigurable PM (RPM) with different configurations of two rotational and one translational (2R1T) DOFs by using locking equipment, which is the main advantage of the designed robot. The inverse kinematics and singularities of two PMs are analyzed. The stiffness performance of the spatial 3PRR PM is compared with that of a moving slider with one translational DOF. By evaluating the workspace and motion/force transmissibility, the kinematic performance of two PMs is presented by using several local and global indices, followed by the dimensional optimization of link parameters. Based on the structural characteristics and excellent performance, it can be inferred that the 3PRR-3PSS-UPU RHR has great potential for machining of large workpieces.
{"title":"Design and Analysis of a Reconfigurable Hybrid Robot for Machining of Large Workpieces","authors":"Lingmin Xu, Xinxue Chai, Ye Ding","doi":"10.1115/1.4062607","DOIUrl":"https://doi.org/10.1115/1.4062607","url":null,"abstract":"\u0000 Large workpieces are important components of core equipment in aerospace and other fields, where the machining mainly focuses on the surfaces and inner cavities. However, there are no machining robots that can not only achieve high-precision surface machining, but also perform the machining of different inner cavities in a limited space. To fill this gap, a new reconfigurable hybrid robot (RHR) is proposed, called the 3PRR-3PSS-UPU RHR, for machining the surface and inner cavity of large workpieces (where P, P, R, S, and U stand for the actuated prismatic joint, passive prismatic joint, revolute joint, spherical joint, and universal joint, respectively). The proposed RHR consists of two parallel manipulators (PMs), in which one is a spatial 3PRR PM with one translational degree of freedom (DOF) and the other is a 3PSS-UPU reconfigurable PM (RPM) with different configurations of two rotational and one translational (2R1T) DOFs by using locking equipment, which is the main advantage of the designed robot. The inverse kinematics and singularities of two PMs are analyzed. The stiffness performance of the spatial 3PRR PM is compared with that of a moving slider with one translational DOF. By evaluating the workspace and motion/force transmissibility, the kinematic performance of two PMs is presented by using several local and global indices, followed by the dimensional optimization of link parameters. Based on the structural characteristics and excellent performance, it can be inferred that the 3PRR-3PSS-UPU RHR has great potential for machining of large workpieces.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43436601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Siying Long, Tatsuro Terakawa, Mahiro Yogou, Rintaro Koyano, M. Komori
Omnidirectional mobility is required for the efficient movement of transport vehicles in factories and warehouses. To meet this requirement, the active omni wheel with barrel-shaped rollers (AOWBR) was previously proposed. The barrel-shaped rollers are arranged around the outer circumference of the main wheel of the AOWBR. This structure is expected to be effective in suppressing vibration during vehicle movement. The transmission roller drives the outer roller via a friction drive, which actively moves the AOWBR in the lateral direction. However, the friction drive may cause slippage between the transmission roller and the outer roller. To solve this problem, this study investigates the effects of the design parameters for an AOWBR on vibration and wheel slippage. The kinetic models of the wheel main body, transmission roller, and outer roller are established. Then, simulations are carried out using the kinetic models for various structural parameter values. The simulation results show that a softer rubber block installed in the support mechanism of the outer roller contributes to reduce wheel slippage but cause larger vibration, and that a larger setting angle between the transmission and outer rollers contributes to reduce slippage and vibration. Finally, comparison experiments are conducted on two types of prototype to verify the simulation results.
{"title":"Kinetic analysis of active omni wheel with barrel-shaped rollers for avoiding slippage and vibration","authors":"Siying Long, Tatsuro Terakawa, Mahiro Yogou, Rintaro Koyano, M. Komori","doi":"10.1115/1.4062608","DOIUrl":"https://doi.org/10.1115/1.4062608","url":null,"abstract":"\u0000 Omnidirectional mobility is required for the efficient movement of transport vehicles in factories and warehouses. To meet this requirement, the active omni wheel with barrel-shaped rollers (AOWBR) was previously proposed. The barrel-shaped rollers are arranged around the outer circumference of the main wheel of the AOWBR. This structure is expected to be effective in suppressing vibration during vehicle movement. The transmission roller drives the outer roller via a friction drive, which actively moves the AOWBR in the lateral direction. However, the friction drive may cause slippage between the transmission roller and the outer roller. To solve this problem, this study investigates the effects of the design parameters for an AOWBR on vibration and wheel slippage. The kinetic models of the wheel main body, transmission roller, and outer roller are established. Then, simulations are carried out using the kinetic models for various structural parameter values. The simulation results show that a softer rubber block installed in the support mechanism of the outer roller contributes to reduce wheel slippage but cause larger vibration, and that a larger setting angle between the transmission and outer rollers contributes to reduce slippage and vibration. Finally, comparison experiments are conducted on two types of prototype to verify the simulation results.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43378741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qiang Yang, Qinghua Zhou, Guangwu Zhou, Ming Jiang, Zhikuan Zhao
Cable-driven hyper-redundant manipulator (CDHM) with flexible and compliant configuration has high maneuverability in a tight space owing to its multiple degrees of freedom (DOFs). However, an increase in the DOFs of the manipulator makes it very challenging to solve its inverse kinematics. The present work proposes a novel adaptive piecewise geometry method to solve the inverse kinematics of the CDHM. The corresponding computation efficiency will be much lower for traditional methods, i.e., the generalized inverse of the Jacobian matrix and artificial neural network method. When the end-effector of the manipulator is required to move with a larger range, Joint angle physical limit need to be considered and the proposed method can select the optimal arc configuration to solve the inverse kinematics aiming at reducing joint overrun. An adaptive adjustment coefficient is further introduced to optimize the configuration so that joint motion more reasonable as well as avoid singular configuration. The geometry and joint parameters solved with the proposed novel method are then compared to those of the existing method with the same desired target position to verify the effective of the proposed novel method. Finally, a 12-DOFs hyper-redundant manipulator physical prototype is built, and corresponding experimental results show that with the novel solution method, the manipulator end can precisely reach the expected target position with significantly less computational complexity, which is beneficial to improve real-time control efficiency of the CDHM in practical applications.
{"title":"Inverse Kinematics Solution Method of an Adaptive Piecewise Geometry for Cable-Driven Hyper-Redundant Manipulator","authors":"Qiang Yang, Qinghua Zhou, Guangwu Zhou, Ming Jiang, Zhikuan Zhao","doi":"10.1115/1.4062606","DOIUrl":"https://doi.org/10.1115/1.4062606","url":null,"abstract":"\u0000 Cable-driven hyper-redundant manipulator (CDHM) with flexible and compliant configuration has high maneuverability in a tight space owing to its multiple degrees of freedom (DOFs). However, an increase in the DOFs of the manipulator makes it very challenging to solve its inverse kinematics. The present work proposes a novel adaptive piecewise geometry method to solve the inverse kinematics of the CDHM. The corresponding computation efficiency will be much lower for traditional methods, i.e., the generalized inverse of the Jacobian matrix and artificial neural network method. When the end-effector of the manipulator is required to move with a larger range, Joint angle physical limit need to be considered and the proposed method can select the optimal arc configuration to solve the inverse kinematics aiming at reducing joint overrun. An adaptive adjustment coefficient is further introduced to optimize the configuration so that joint motion more reasonable as well as avoid singular configuration. The geometry and joint parameters solved with the proposed novel method are then compared to those of the existing method with the same desired target position to verify the effective of the proposed novel method. Finally, a 12-DOFs hyper-redundant manipulator physical prototype is built, and corresponding experimental results show that with the novel solution method, the manipulator end can precisely reach the expected target position with significantly less computational complexity, which is beneficial to improve real-time control efficiency of the CDHM in practical applications.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48804166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, a new algorithm for the computation of workspace boundaries of continuum parallel robots (CPRs) is proposed. State-of-the-art techniques are mainly based on time-consuming joint-space discretization approaches or task-space discretization algorithms, and only a few approaches are dedicated to the computation of workspace boundaries. The proposed approach for the computation of the workspace boundaries is based on i) a free-space exploration strategy and ii) a boundary reconstruction algorithm. The former is exploited to identify an initial workspace boundary location (exterior, interior boundaries, and holes), while the latter is used to reconstruct the complete boundary surface. Moreover, the algorithm is designed to be employed with CPRs modelling strategies based on general discretization assumptions, in order to increase its applicability for various scopes. Our method is compared with two state-of-the-art algorithms in four case studies to validate the results and to establish its merits and limitations.
{"title":"A Boundary Computation Algorithm for the Workspace Evaluation of Continuum Parallel Robots","authors":"F. Zaccaria, E. Idà, S. Briot","doi":"10.1115/1.4062585","DOIUrl":"https://doi.org/10.1115/1.4062585","url":null,"abstract":"\u0000 In this paper, a new algorithm for the computation of workspace boundaries of continuum parallel robots (CPRs) is proposed. State-of-the-art techniques are mainly based on time-consuming joint-space discretization approaches or task-space discretization algorithms, and only a few approaches are dedicated to the computation of workspace boundaries. The proposed approach for the computation of the workspace boundaries is based on i) a free-space exploration strategy and ii) a boundary reconstruction algorithm. The former is exploited to identify an initial workspace boundary location (exterior, interior boundaries, and holes), while the latter is used to reconstruct the complete boundary surface. Moreover, the algorithm is designed to be employed with CPRs modelling strategies based on general discretization assumptions, in order to increase its applicability for various scopes. Our method is compared with two state-of-the-art algorithms in four case studies to validate the results and to establish its merits and limitations.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48638059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Rodríguez-Guerra, Gorka Sorrosal, I. Cabanes, Aitziber Mancisidor, Carlos Calleja
Most of the current commercial collaborative robots present a non-spherical wrist, so they cannot utilize singularity handling techniques efficiently to avoid excessive safety stops while dynamically avoiding collisions. These robots usually require heavier algorithms due to their kinematics or online methods that shift the original singularities. Therefore, to enable more efficient computations on singularity handling and collision avoidance controllers, this manuscript proposes a novel method to characterize singular configurations of non-spherical wrist collaborative robots (6 and 7 Degrees of Freedom). This method is based on a new decoupled kinematic model that allows lighter kinematic computations and enables the joint-dependant characterization of the robot singularities to avoid shifting the singular configurations. Finally, the proposed kinematic model is particularized for a UR10e, where its kinematic behavior has been tested against two different literature models in simulation. In this manner, a novel singularity category (belonging to the internal singularities) is proposed, and a new closed set of characterized singular solutions is obtained.
{"title":"Singularity parametrization with a novel kinematic decoupled model for non-spherical wrist robots","authors":"D. Rodríguez-Guerra, Gorka Sorrosal, I. Cabanes, Aitziber Mancisidor, Carlos Calleja","doi":"10.1115/1.4062586","DOIUrl":"https://doi.org/10.1115/1.4062586","url":null,"abstract":"\u0000 Most of the current commercial collaborative robots present a non-spherical wrist, so they cannot utilize singularity handling techniques efficiently to avoid excessive safety stops while dynamically avoiding collisions. These robots usually require heavier algorithms due to their kinematics or online methods that shift the original singularities. Therefore, to enable more efficient computations on singularity handling and collision avoidance controllers, this manuscript proposes a novel method to characterize singular configurations of non-spherical wrist collaborative robots (6 and 7 Degrees of Freedom). This method is based on a new decoupled kinematic model that allows lighter kinematic computations and enables the joint-dependant characterization of the robot singularities to avoid shifting the singular configurations. Finally, the proposed kinematic model is particularized for a UR10e, where its kinematic behavior has been tested against two different literature models in simulation. In this manner, a novel singularity category (belonging to the internal singularities) is proposed, and a new closed set of characterized singular solutions is obtained.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48778462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to the lack of connection between configuration synthesis and performance indices, many configurations obtained cannot meet the performance requirements, increasing the difficulty of configuration selection and prolonging the design cycle of the parallel mechanism (PM). In order to solve this problem, this paper proposes an inverse Jacobian matrix construction method based on performance indices. The method is realized by constructing singular values and singular vectors directly related to the performance indices. Furthermore, based on the screw expression form of the inverse Jacobian matrix, a new integrated design method that can directly meet the performance requirements is proposed. Finally, a novel ankle rehabilitation mechanism is presented using this method, and the correctness and effectiveness of the integrated design method are verified by theoretical analysis. Meanwhile, the analysis results show that the proposed method can effectively shorten PM's design time and simplify PM's design process, which has a good application value.
{"title":"A Novel Integrated Design Method of Parallel Mechanisms Based on Performance Requirements","authors":"Shihua Li, Yunzhan Niu, Jilong Xu, Haibo Yu","doi":"10.1115/1.4062549","DOIUrl":"https://doi.org/10.1115/1.4062549","url":null,"abstract":"\u0000 Due to the lack of connection between configuration synthesis and performance indices, many configurations obtained cannot meet the performance requirements, increasing the difficulty of configuration selection and prolonging the design cycle of the parallel mechanism (PM). In order to solve this problem, this paper proposes an inverse Jacobian matrix construction method based on performance indices. The method is realized by constructing singular values and singular vectors directly related to the performance indices. Furthermore, based on the screw expression form of the inverse Jacobian matrix, a new integrated design method that can directly meet the performance requirements is proposed. Finally, a novel ankle rehabilitation mechanism is presented using this method, and the correctness and effectiveness of the integrated design method are verified by theoretical analysis. Meanwhile, the analysis results show that the proposed method can effectively shorten PM's design time and simplify PM's design process, which has a good application value.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49040872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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