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Jaime Gallardo-alvarado - One of the best experts on this subject based on the ideXlab platform.

  • A Simple Method to Solve the Instantaneous Kinematics of the 5-R UR Parallel Manipulator
    Robotica, 2019
    Co-Authors: Jaime Gallardo-alvarado, Mohammad H. Abedinnasab, Nazrul Islam
    Abstract:

    In this work a simple method to solve the kinematics of the 5-R UR parallel manipulator is introduced. Dealing with the displacement analysis, the kinematic constraint equations required to address the forward–inverse displacement analysis are established according to linear combinations of two vectors attached to the moving platform. Then, besides the solution of the inverse displacement analysis two strategies are proposed in order to solve the forward position analysis. Finally, the input–output equations of velocity and acceleration are systematically obtained by resorting to Reciprocal-Screw Theory. Numerical examples are provided with the purpose to illustrate the proposed method. Furthermore, the numerical results obtained by means of Screw Theory are confirmed with the aid of commercially available software.

  • A Five-Bar Planar Parallel Manipulator with Two End-Effectors
    2018
    Co-Authors: Jaime Gallardo-alvarado, Ramon Rodriguez-castro, Luciano Perez-gonzalez, Carlos R. Aguilar-najera, Álvaro Sánchez-rodríguez
    Abstract:

    Parallel manipulators with multiple end-effectors bring us interesting advantages over conventional parallel manipulators such as improved manipulability, workspace and avoidance of singularities. In this work the kinematics of a five-bar planar parallel manipulator equipped with two end-effectors is approached by means of the Theory of Screws. As an intermediate step the displacement analysis of the robot is also investigated. The input-output equations of velocity and acceleration are systematically obtained by resorting to Reciprocal-Screw Theory. In that regard the Klein form of the Lie algebra se(3) of the Euclidean group SE(3) plays a central role. In order to exemplify the method of kinematic analysis, a case study is included. Furthermore, the numerical results obtained by means of the Theory of Screws are confirmed with the aid of special software like ADAMS.TM

  • Kinematics of the 3(RPSP)-S Fully Spherical Parallel Manipulator by Means of Screw Theory
    MDPI AG, 2018
    Co-Authors: Jaime Gallardo-alvarado, Ramon Rodriguez-castro, Luciano Perez-gonzalez, Carlos R. Aguilar-najera
    Abstract:

    In this work, the kinematics of a spherical parallel manipulator composed of three peripheral limbs equipped with linear actuators and a passive center shaft is approached by means of the Theory of Screws. The displacement analysis is carried out solving closure equations, which are obtained upon simple linear combinations of the components of two unit vectors describing the orientation of the moving platform. After, the input-output equations of velocity and acceleration of the spherical parallel manipulator are systematically obtained by resorting to Reciprocal-Screw Theory. This strategy avoids the computation of the passive joint velocity and acceleration rates of the robot manipulator. Numerical examples illustrate the efficiency of the proposed method

  • Kinematics of the 4-RUU parallel manipulator generator of the Schönflies motion by means of Screw Theory
    Journal of Mechanical Science and Technology, 2017
    Co-Authors: Jaime Gallardo-alvarado, Mario A. García-murillo, Md. Nazrul Islam, Mohammad H. Abedinnasab
    Abstract:

    This work deals with the inverse–forward kinematic analysis of a symmetric parallel manipulator equipped with a rotary actuator generator of three independent translations and one rotation motion. The closure equations of the displacement analysis are easily formulated based on the unknown coordinates of two points embedded in the moving platform. The input–output equations of velocity and acceleration of the robot are systematically obtained through the Reciprocal-Screw Theory. The pseudo-kinematic pairs that connect the limbs to the fixed platform and a passive kinematic chain connected to the robot manipulator eliminate the handling of rank-deficient Jacobian matrices, which is an undisputable advantage from the computational point of view. Furthermore, this strategy allows the use of the Lie algebra se (3) without the inherent restrictions associated with the limited mobility of the robot.

  • Análisis Cinemático del Manipulador Paralelo 4-PRUR Mediante la Teoría de Tornillos
    Revista Iberoamericana de Automática e Informática Industrial RIAI, 2017
    Co-Authors: Jaime Gallardo-alvarado, Mario A. García-murillo
    Abstract:

    In this work the kinematics of a parallel manipulator performing Schonflies motion is investigated by means of the Theory ¨ of Screws. As an intermediate step, the displacement analysis is reported in semi-closed form solution based on the coordinates of two points embedded in the moving platform. This strategy allows to employ only one reference frame avoiding the computation of the rotation matrix. The input-output equations of velocity and acceleration are systematically obtained by resorting to Reciprocal-Screw Theory. To this aim, the robot is treated as a six-degrees-of-freedom parallel manipulator incorporating pseudo kinematic pairs connecting the limbs to the fixed platform and one virtual kinematic chain in order to apply without restrictions the Lie algebra se(3) of the Euclidean group S E(3). The singularity analysis is investigated based on the input-output equation of velocity. Numerical examples are included in order to show the application of the method.

Sunil K. Agrawal - One of the best experts on this subject based on the ideXlab platform.

  • On the Force-Closure Analysis of n-DOF Cable-Driven Open Chains Based on Reciprocal Screw Theory
    IEEE Transactions on Robotics, 2012
    Co-Authors: Shabbir Kurbanhusen Mustafa, Sunil K. Agrawal
    Abstract:

    It has been mathematically proven that a completely restrained n- degree-of-freedom (n-DOF) single rigid-bodied cable-driven platform requires a minimum of n + 1 cables with positive tension to fully constrain it. However, the force-closure analysis of open chains that are driven by cables is still an open question. For the case of an n -DOF cable-driven open chain, the following two important questions arise. 1) How can the force-closure analysis be carried out for a given cable routing configuration, while retaining the geometric insights of the problem? 2) Are n + 1 cables sufficient to fully constrain the entire chain? This paper addresses these issues by proposing a systematic and novel approach based on the Reciprocal Screw Theory. The key idea is to express wrenches acting on the open chain as linear combinations of the Reciprocal Screws and determine the total required torques at each joint. This is followed by equating the joint torques that are provided by the cable forces with the joint torques, which are required by the external wrenches, and checking for force closure. The proposed methodology can analyze open chains with arbitrary cable routing configuration. The analysis shows that the entire n-DOF open chain requires a minimum of n + 1 cables to fully constrain it.

  • ICRA - Force-closure of spring-loaded cable-driven open chains: Minimum number of cables required & influence of spring placements
    2012 IEEE International Conference on Robotics and Automation, 2012
    Co-Authors: Shabbir Kurbanhusen Mustafa, Sunil K. Agrawal
    Abstract:

    While cable-driven systems offer the advantages of being lightweight with low moving inertia, the unilateral driving property of cables generally require them to have a greater number of actuators than their rigid-linked counterparts. This paper investigates the use of springs in an attempt to reduce the number of cables required. Given an n-DOF spring-loaded cable-driven open chain, several important questions arise: (i) How can force-closure analysis be carried out for a given spring and cable routing configuration? (ii) Are n+1 cables still necessary to fully constrain the entire open chain? (iii) What is the influence of spring placement on force-closure and cable tension required? This paper will address these concerns by proposing a systematic approach based on Reciprocal Screw Theory. The analysis shows that an n-DOF spring-loaded cable-driven open chain still requires a minimum of n+1 cables to fully constrain it. From preliminary analysis, spring placement can have a positive effect on altering the cable tension required and increasing the feasible workspace.

  • Reciprocal Screw-Based Force-Closure of Cable-Driven Closed Chains
    Volume 6: 35th Mechanisms and Robotics Conference Parts A and B, 2011
    Co-Authors: Shabbir Kurbanhusen Mustafa, Sunil K. Agrawal
    Abstract:

    Extensive research has been conducted in force-closure analysis of single rigid-bodied cable-driven platforms, and very recently of cable-driven open chains. However, force-closure analysis of cable-driven closed chains is still an open question. For the case of an n-DOF closed chain driven by cables, two important questions arise: (i) How can force-closure analysis be carried out for a given cable routing configuration while retaining the geometric insights of the problem? (ii) Are n+1 cables sufficient to fully constrain the entire closed chain? This paper will address these issues and propose a systematic and novel approach based on the Reciprocal Screw Theory. The proposed methodology can analyze closed chains with arbitrary cable routings and the analysis shows that an n-DOF closed chain requires a minimum of n+1 cables to fully constrain it.Copyright © 2011 by ASME

  • ICRA - Reciprocal Screw-based force-closure of an n-DOF open chain: Minimum number of cables required to fully constrain it
    2011 IEEE International Conference on Robotics and Automation, 2011
    Co-Authors: Shabbir Kurbanhusen Mustafa, Sunil K. Agrawal
    Abstract:

    Due to the unilateral driving property of cables, it has been mathematically proven that a 6-DOF single rigid-bodied cable-driven platform requires a minimum of 7 cables with positive tension to fully constrain it. However, force-closure analysis of open chains driven by cables is still an open question. For the case of an n-DOF open chain driven by cables, two important questions arise: (i) Are n+1 cables sufficient to fully constrain the entire chain? (ii) How can force-closure analysis be carried out for a given cable routing configuration while retaining the geometric insights of the problem? This paper will address these issues and propose a systematic and novel approach based on the Reciprocal Screw Theory. The analysis shows that the entire n-DOF open chain requires a minimum of n+1 cables to fully constrain it and the proposed methodology can analyze any cable routing configuration.

Z. Huang - One of the best experts on this subject based on the ideXlab platform.

  • general methodology for type synthesis of symmetrical lower mobility parallel manipulators and several novel manipulators
    The International Journal of Robotics Research, 2002
    Co-Authors: Z. Huang
    Abstract:

    In the area of parallel robots, the use of lower-mobility parallel manipulators for many tasks requiring fewer than six degrees of freedom (DoF) has drawn a lot of interest. This paper treats one fundamental problem in the study of lower-mobility parallel manipulators: type synthesis. Using Reciprocal Screw Theory, we define the mechanism constraint system and limb constraint system. We then investigate the relations between the mechanism constraint system and the limb constraint system under different geometrical conditions. Three tables describing the relations are presented. Based on the three tables, we propose a constraint-synthesis method for type synthesis of symmetrical lower-mobility parallel manipulators. The method used in the paper to construct the kinematic structure of the limb of lower-mobility parallel manipulators with prescribed DoF is simple and systematic. Examples are included to illustrate the application of the method and some novel lower-mobility parallel manipulators with 3-, 4- a...

  • Construction and Kinematic Properties of 3-UPU Parallel Mechanisms
    Volume 5: 27th Biennial Mechanisms and Robotics Conference, 2002
    Co-Authors: Z. Huang
    Abstract:

    The assembly condition of universal pairs in the 3-UPU parallel mechanism determines the mechanism mobility. This paper uses Reciprocal Screw Theory to study mobility analysis of the 3-UPU parallel mechanism under several different assembly conditions. The analysis and the method presented in this paper will be helpful in using the 3-UPU parallel mechanism and introduce new insights into the mobility analysis of parallel mechanisms.© 2002 ASME

  • General methodology for type synthesis of symmetrical lower-mobility parallel manipulators and several novel manipulators
    2002
    Co-Authors: Z. Huang
    Abstract:

    In the area of parallel robots, the use of lower-mobility parallel ma-nipulators for many tasks requiring fewer than six degrees of freedom (DoF) has drawn a lot of interest. This paper treats one fundamental problem in the study of lower-mobility parallel manipulators: type synthesis. Using Reciprocal Screw Theory, we define the mechanism constraint system and limb constraint system. We then investigate the relations between the mechanism constraint system and the limb constraint system under different geometrical conditions. Three ta-bles describing the relations are presented. Based on the three tables, we propose a constraint-synthesis method for type synthesis of sym-metrical lower-mobility parallel manipulators. The method used in the paper to construct the kinematic structure of the limb of lower-mobility parallel manipulators with prescribed DoF is simple and systematic. Examples are included to illustrate the application of the method and some novel lower-mobility parallel manipulators with 3-, 4- and 5-DoF are synthesized. KEY WORDS—parallel mechanism, type synthesis, design Theory 1

Shabbir Kurbanhusen Mustafa - One of the best experts on this subject based on the ideXlab platform.

  • On the Force-Closure Analysis of n-DOF Cable-Driven Open Chains Based on Reciprocal Screw Theory
    IEEE Transactions on Robotics, 2012
    Co-Authors: Shabbir Kurbanhusen Mustafa, Sunil K. Agrawal
    Abstract:

    It has been mathematically proven that a completely restrained n- degree-of-freedom (n-DOF) single rigid-bodied cable-driven platform requires a minimum of n + 1 cables with positive tension to fully constrain it. However, the force-closure analysis of open chains that are driven by cables is still an open question. For the case of an n -DOF cable-driven open chain, the following two important questions arise. 1) How can the force-closure analysis be carried out for a given cable routing configuration, while retaining the geometric insights of the problem? 2) Are n + 1 cables sufficient to fully constrain the entire chain? This paper addresses these issues by proposing a systematic and novel approach based on the Reciprocal Screw Theory. The key idea is to express wrenches acting on the open chain as linear combinations of the Reciprocal Screws and determine the total required torques at each joint. This is followed by equating the joint torques that are provided by the cable forces with the joint torques, which are required by the external wrenches, and checking for force closure. The proposed methodology can analyze open chains with arbitrary cable routing configuration. The analysis shows that the entire n-DOF open chain requires a minimum of n + 1 cables to fully constrain it.

  • ICRA - Force-closure of spring-loaded cable-driven open chains: Minimum number of cables required & influence of spring placements
    2012 IEEE International Conference on Robotics and Automation, 2012
    Co-Authors: Shabbir Kurbanhusen Mustafa, Sunil K. Agrawal
    Abstract:

    While cable-driven systems offer the advantages of being lightweight with low moving inertia, the unilateral driving property of cables generally require them to have a greater number of actuators than their rigid-linked counterparts. This paper investigates the use of springs in an attempt to reduce the number of cables required. Given an n-DOF spring-loaded cable-driven open chain, several important questions arise: (i) How can force-closure analysis be carried out for a given spring and cable routing configuration? (ii) Are n+1 cables still necessary to fully constrain the entire open chain? (iii) What is the influence of spring placement on force-closure and cable tension required? This paper will address these concerns by proposing a systematic approach based on Reciprocal Screw Theory. The analysis shows that an n-DOF spring-loaded cable-driven open chain still requires a minimum of n+1 cables to fully constrain it. From preliminary analysis, spring placement can have a positive effect on altering the cable tension required and increasing the feasible workspace.

  • Reciprocal Screw-Based Force-Closure of Cable-Driven Closed Chains
    Volume 6: 35th Mechanisms and Robotics Conference Parts A and B, 2011
    Co-Authors: Shabbir Kurbanhusen Mustafa, Sunil K. Agrawal
    Abstract:

    Extensive research has been conducted in force-closure analysis of single rigid-bodied cable-driven platforms, and very recently of cable-driven open chains. However, force-closure analysis of cable-driven closed chains is still an open question. For the case of an n-DOF closed chain driven by cables, two important questions arise: (i) How can force-closure analysis be carried out for a given cable routing configuration while retaining the geometric insights of the problem? (ii) Are n+1 cables sufficient to fully constrain the entire closed chain? This paper will address these issues and propose a systematic and novel approach based on the Reciprocal Screw Theory. The proposed methodology can analyze closed chains with arbitrary cable routings and the analysis shows that an n-DOF closed chain requires a minimum of n+1 cables to fully constrain it.Copyright © 2011 by ASME

  • ICRA - Reciprocal Screw-based force-closure of an n-DOF open chain: Minimum number of cables required to fully constrain it
    2011 IEEE International Conference on Robotics and Automation, 2011
    Co-Authors: Shabbir Kurbanhusen Mustafa, Sunil K. Agrawal
    Abstract:

    Due to the unilateral driving property of cables, it has been mathematically proven that a 6-DOF single rigid-bodied cable-driven platform requires a minimum of 7 cables with positive tension to fully constrain it. However, force-closure analysis of open chains driven by cables is still an open question. For the case of an n-DOF open chain driven by cables, two important questions arise: (i) Are n+1 cables sufficient to fully constrain the entire chain? (ii) How can force-closure analysis be carried out for a given cable routing configuration while retaining the geometric insights of the problem? This paper will address these issues and propose a systematic and novel approach based on the Reciprocal Screw Theory. The analysis shows that the entire n-DOF open chain requires a minimum of n+1 cables to fully constrain it and the proposed methodology can analyze any cable routing configuration.

Yongsheng Zhao - One of the best experts on this subject based on the ideXlab platform.

  • Type synthesis of overconstrained 2R1T parallel mechanisms with the fewest kinematic joints based on the ultimate constraint wrenches
    Mechanism and Machine Theory, 2020
    Co-Authors: Zhao Yun, Jiantao Yao, Yongsheng Zhao
    Abstract:

    Abstract “Two rotational degrees of freedom” and “one translational degree of freedom” (2R1T) parallel mechanisms (PMs) have been successfully applied to develop five-axis hybrid robots for machining purposes. However, the number of passive joints contained in current 2R1T PMs has not still reached the minimum, which may impede these robots from having high stiffness. This study has put forward the concept of ultimate constraint wrenches acting on the PM's moving platform, and this concept was used to reduce the number of kinematic joints to a minimum. Based on the Reciprocal Screw Theory, an ultimate constraint wrench system of the 2R1T PMs was found, and then a series of novel overconstrained 2R1T PMs with the fewest kinematic joints, containing three or four branches, were constructed. Furthermore, based on a developed overconstrained four-branch 2R1T PM R P U-2U P R-RPR, a type of five-axis hybrid robot with the fewest kinematic joints was constructed, which demonstrated good application prospects.

  • Type Synthesis of the Deployable Mechanisms for the Truss Antenna Using the Method of Adding Constraint Chains
    Journal of Mechanisms and Robotics, 2018
    Co-Authors: Chen Liangliang, Liu Wenlan, Jiantao Yao, Jialong Zhu, Yongsheng Zhao
    Abstract:

    In the deployable mechanism for a conventional truss antenna, the nodes cannot be adjusted to be uniform in attitude. To solve this problem, a method of adding constraint chains is proposed based on the Reciprocal Screw Theory. By performing type synthesis of the deployable mechanisms for the truss antenna, a novel deployable mechanism is developed that not only enables complete folding and unfolding but also allows the attitude of the nodes to be made uniform. First, according to the unit division of the antenna reflection surface and the characteristic motions of the nodes, constraint chains that can be added between two adjacent nodes are synthesized based on the Reciprocal Screw Theory. Second, to improve the overall rigidity of the mechanism, a series of basic developable unit mechanisms is obtained by adding virtual constraint chains, again based on the Reciprocal Screw Theory. Next, a method of dividing the minimum combination unit of the curved-surface antenna mechanism is proposed. The design of the minimum combination unit mechanism is optimized, such that the attitude of all nodes in the final folded state can be made consistent. Finally, the feasibility of the optimized minimum combination unit mechanism is verified by simulation analysis. The proposed method for type synthesis provides a new approach to the design of deployable mechanisms for truss antennas, and novel deployable mechanisms for the curved-surface truss antenna with better performance are obtained.

  • DOF and Kinematic Analysis of a Deployable Truss Antenna Assembled by Tetrahedral Elements
    Lecture Notes in Electrical Engineering, 2016
    Co-Authors: Liu Wenlan, Jiantao Yao, Yongsheng Zhao, Chen Liangliang
    Abstract:

    Deployable structure has played a more and more important role in the large-caliber antennas. This paper deals with the degree of freedom (DOF) and kinematics of a kind of deployable truss antenna composed of tetrahedral elements. Firstly, based on the Reciprocal Screw Theory the DOF of one tetrahedral element is analyzed. Then, the equivalent mechanism of the minimum composite unit of the deployable truss antenna is obtained according to the characteristic of the DOF of the tetrahedral element. Sequentially, the DOF of the deployable truss antenna is derived. Further, the analytical expressions of the positions and velocities of the connection nodes of the antenna during its deploying/folding process are formulated by resorting to the coordinate transformation matrices. Finally, the correctness of the kinematic analysis of the deployable truss antenna is verified by simulation based on the Adams software.

  • Type Synthesis of the Hybrid Rotary Platform Mechanism with Three Degrees of Freedom
    Lecture Notes in Electrical Engineering, 2016
    Co-Authors: Xu Yundou, Chen Liangliang, Yan Wennan, Wang Bei, Yongsheng Zhao
    Abstract:

    To improve the carrying capacity, a novel hybrid mechanism for rotary platform with three degrees of freedom (DOFs) is proposed, the serial mechanism is located on the moving platform (MP) of the parallel mechanism (PM), but its actuation system are located on the base, and the rolling motion is transferred by a motion transferring chain. The constraint wrench imposed on the upper MP of the hybrid rotary platform is analyzed, the type synthesis of the motion transferring chain was carried out using the constraint-synthesis method based on Reciprocal Screw Theory. The relationship between input of the transferring chain and output of the upper MP is established, then the principle of transferring rolling motion by the motion transferring chain is explained. Finally, based on the motion transferring chain after optimization, two hybrid mechanisms for the rotary platform with three DOFs are obtained, which can meet the demands presented above.

  • Stiffness modelling and comparison of the 5-UPS/PRPU parallel machine tool with its non-redundant counterpart
    Proceedings of the Institution of Mechanical Engineers Part B: Journal of Engineering Manufacture, 2016
    Co-Authors: Xin Zhou, Jiantao Yao, Kuijing Zheng, Yongsheng Zhao
    Abstract:

    This article presents a derivation of the stiffness matrix of a general redundantly actuated parallel mechanism based on the overall Jacobian. The Jacobian of the constraints and actuations is derived using Reciprocal Screw Theory. Based on the mapping relationship between constraint, actuated and external forces combined with the principle of virtual work, a compatibility equation for the deformation of all of the limbs is achieved, and the stiffness model of the general redundantly actuated parallel mechanism is derived. The 5-UPS/PRPU redundantly actuated parallel machine tool is used to illustrate this method. The parallel machine tool comprehensively reveals the effect of the elastic deformation of active–passive joints and some basic transmission parts. The stiffness model is further validated by experimental data. Moreover, the global stiffness matrix of the general redundantly actuated parallel mechanism can be separated into two parts via matrix decomposition. The first part is the stiffness matr...