The Experts below are selected from a list of 12069 Experts worldwide ranked by ideXlab platform
Imme Ebert-uphoff - One of the best experts on this subject based on the ideXlab platform.
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Wrench-feasible workspace generation for cable-driven robots
IEEE Transactions on Robotics, 2006Co-Authors: Paul Bosscher, Andrew T. Riechel, Imme Ebert-uphoffAbstract:This paper presents a method for analytically generating the boundaries of the wrench-feasible workspace (WFW) for cable robots. This method uses the available net wrench set, which is the set of all wrenches that a cable robot can apply to its surroundings without violating tension limits in the cables. The geometric properties of this set permit calculation of the boundaries of the WFW for planar, spatial, and point-mass cable robots. Complete analytical expressions for the WFW boundaries are detailed for a planar cable robot and a spatial point-mass cable robot. The analytically determined boundaries are verified by comparison with numerical results. Based on this, several workspace properties are shown for point-mass cable robots. Finally, it is shown how this workspace-generation approach can be used to analytically formulate other Workspaces
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Wrench-based analysis of cable-driven robots
IEEE International Conference on Robotics and Automation 2004. Proceedings. ICRA '04. 2004, 2004Co-Authors: Paul Bosscher, Imme Ebert-uphoffAbstract:This paper introduces the available net wrench set, which is the set of all wrenches that a cable robot can apply to its surroundings without violating tension limits in the cables. This set is used as a framework for understanding and computing wrench-feasibility of a pose of the robot, allowing wrench-feasibility to be tested in the task space. The geometric properties of the available net wrench set are then exploited to permit simple geometric calculation of the boundaries of the wrench-feasible workspace. This workspace generation is extended to two other Workspaces as well. Other design tools, including payload specification and failure analysis, are also presented.
Sunil K. Agrawal - One of the best experts on this subject based on the ideXlab platform.
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optimal design of cable driven manipulators using particle swarm optimization
Journal of Mechanisms and Robotics, 2016Co-Authors: Joshua T. Bryson, Xin Jin, Sunil K. AgrawalAbstract:The design of cable-driven manipulators is complicated by the unidirectional nature of the cables, which results in extra actuators and limited Workspaces. Furthermore, the particular arrangement of the cables and the geometry of the robot pose have a significant effect on the cable tension required to effect a desired joint torque. For a sufficiently complex robot, the identification of a satisfactory cable architecture can be difficult and can result in multiply redundant actuators and performance limitations based on workspace size and cable tensions. This work leverages previous research into the workspace analysis of cable systems combined with stochastic optimization to develop a generalized methodology for designing optimized cable routings for a given robot and desired task. A cable-driven robot leg performing a walking-gait motion is used as a motivating example to illustrate the methodology application. The components of the methodology are described, and the process is applied to the example problem. An optimal cable routing is identified, which provides the necessary controllable workspace to perform the desired task and enables the robot to perform that task with minimal cable tensions. A robot leg is constructed according to this routing and used to validate the theoretical model and to demonstrate the effectiveness of the resulting cable architecture.
Paul Bosscher - One of the best experts on this subject based on the ideXlab platform.
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Wrench-feasible workspace generation for cable-driven robots
IEEE Transactions on Robotics, 2006Co-Authors: Paul Bosscher, Andrew T. Riechel, Imme Ebert-uphoffAbstract:This paper presents a method for analytically generating the boundaries of the wrench-feasible workspace (WFW) for cable robots. This method uses the available net wrench set, which is the set of all wrenches that a cable robot can apply to its surroundings without violating tension limits in the cables. The geometric properties of this set permit calculation of the boundaries of the WFW for planar, spatial, and point-mass cable robots. Complete analytical expressions for the WFW boundaries are detailed for a planar cable robot and a spatial point-mass cable robot. The analytically determined boundaries are verified by comparison with numerical results. Based on this, several workspace properties are shown for point-mass cable robots. Finally, it is shown how this workspace-generation approach can be used to analytically formulate other Workspaces
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Wrench-based analysis of cable-driven robots
IEEE International Conference on Robotics and Automation 2004. Proceedings. ICRA '04. 2004, 2004Co-Authors: Paul Bosscher, Imme Ebert-uphoffAbstract:This paper introduces the available net wrench set, which is the set of all wrenches that a cable robot can apply to its surroundings without violating tension limits in the cables. This set is used as a framework for understanding and computing wrench-feasibility of a pose of the robot, allowing wrench-feasibility to be tested in the task space. The geometric properties of the available net wrench set are then exploited to permit simple geometric calculation of the boundaries of the wrench-feasible workspace. This workspace generation is extended to two other Workspaces as well. Other design tools, including payload specification and failure analysis, are also presented.
Xin-jun Liu - One of the best experts on this subject based on the ideXlab platform.
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kinematics singularity and workspace of planar 5r symmetrical parallel mechanisms
Mechanism and Machine Theory, 2006Co-Authors: Xin-jun Liu, Jinsong Wang, Gunter PritschowAbstract:This paper treats the problems of kinematics, singularity and workspace analysis of the 5R symmetrical parallel mechanism. In the design process, the theoretical workspace cannot be used directly due to the inside singularity. The inverse and forward kinematic solutions determine the working and assembly modes of a mechanism. With different modes, a mechanism will have different singular loci and Workspaces. In this paper, the singularity and usable workspace without singularity inside will be determined for the mechanism with a specified mode. A concept, the maximal inscribed workspace (MIW) that is bounded by the maximal inscribed circle (MIC), is defined to characterize the workspace performance. A non-dimensional design space is established to investigate the singular loci and workspace shape of the mechanisms, systematically. The atlas of the MIC radius is presented. Based on the obtained distribution charts of the singularity and workspace shape and the atlas, one can know the singularity and workspace performances of any one of the 5R symmetrical parallel mechanisms. The result, especially that of the MIW, of this paper is very useful for the optimum design of the mechanism.
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workspace and rotational capability analysis of a spatial 3 dof parallel manipulator
Progress in Natural Science, 2004Co-Authors: Xin-jun Liu, Jinsong Wang, Qiming WangAbstract:Abstract The analysis on the workspace and rotational capability of HANA, a spatial 3-DoF parallel manipulator, is concerned. The parallel manipulator consists of a base plate, a movable platform, and three connecting legs. The moving platform has three degrees of freedom (DoFs) which are two translations and one rotation, with respect to the base plate. The new parallel manipulator is very interesting for the reason of no singularity in the workspace, the single-DoF joint architecture and high rotational capability of the moving platform. The inverse kinematics problem is described in a closed-form, which is very useful to present the workspace geometrically. The constant-orientation and reachable Workspaces for the manipulator are analyzed firstly. The index that is used to evaluate the rotational capability of the manipulator is defined and discussed in detail. Finally, the distribution of rotational capability index on the workspace is presented, which helps us know how much the index is at different ...
Jinsong Wang - One of the best experts on this subject based on the ideXlab platform.
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optimum design of the 5r symmetrical parallel manipulator with a surrounded and good condition workspace
Robotics and Autonomous Systems, 2006Co-Authors: Jinsong Wang, Haojun ZhengAbstract:Abstract This paper concerns the optimum design issue of the 5R symmetrical parallel manipulator with a surrounded workspace. Generally, such a manipulator has a very large workspace. With different working modes, a manipulator will have different singular loci and Workspaces. In this paper, the singularity and the usable workspace without singularity inside will be determined for the manipulator with a specified mode. The usable workspace can be used to define the global conditioning index (GCI). In order to obtain the optimum design of the manipulator, a non-dimensional design space is established. Because each of the non-dimensional manipulators in the established design space can represent the performances of all of its possible similarity manipulators, the design space is a very useful tool for guaranteeing a global comparative result. Within the design space, the singularity, usable workspace and control accuracy (evaluated using the GCI) are studied and the corresponding atlases are constructed. Based on the atlases, one can synthesize link lengths of the manipulator studied with respect to specified criteria. One example will be given to show how to use the atlases. In particular, an example will be presented of reaching the optimum dimensional result with respect to a desired practical workspace based on the optimum non-dimensional result identified from the atlases. For the reason that using the atlases presented in this paper a designer can obtain the optimum result with respect to any specification, the optimum design method proposed in this paper may be accepted by others.
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kinematics singularity and workspace of planar 5r symmetrical parallel mechanisms
Mechanism and Machine Theory, 2006Co-Authors: Xin-jun Liu, Jinsong Wang, Gunter PritschowAbstract:This paper treats the problems of kinematics, singularity and workspace analysis of the 5R symmetrical parallel mechanism. In the design process, the theoretical workspace cannot be used directly due to the inside singularity. The inverse and forward kinematic solutions determine the working and assembly modes of a mechanism. With different modes, a mechanism will have different singular loci and Workspaces. In this paper, the singularity and usable workspace without singularity inside will be determined for the mechanism with a specified mode. A concept, the maximal inscribed workspace (MIW) that is bounded by the maximal inscribed circle (MIC), is defined to characterize the workspace performance. A non-dimensional design space is established to investigate the singular loci and workspace shape of the mechanisms, systematically. The atlas of the MIC radius is presented. Based on the obtained distribution charts of the singularity and workspace shape and the atlas, one can know the singularity and workspace performances of any one of the 5R symmetrical parallel mechanisms. The result, especially that of the MIW, of this paper is very useful for the optimum design of the mechanism.
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workspace and rotational capability analysis of a spatial 3 dof parallel manipulator
Progress in Natural Science, 2004Co-Authors: Xin-jun Liu, Jinsong Wang, Qiming WangAbstract:Abstract The analysis on the workspace and rotational capability of HANA, a spatial 3-DoF parallel manipulator, is concerned. The parallel manipulator consists of a base plate, a movable platform, and three connecting legs. The moving platform has three degrees of freedom (DoFs) which are two translations and one rotation, with respect to the base plate. The new parallel manipulator is very interesting for the reason of no singularity in the workspace, the single-DoF joint architecture and high rotational capability of the moving platform. The inverse kinematics problem is described in a closed-form, which is very useful to present the workspace geometrically. The constant-orientation and reachable Workspaces for the manipulator are analyzed firstly. The index that is used to evaluate the rotational capability of the manipulator is defined and discussed in detail. Finally, the distribution of rotational capability index on the workspace is presented, which helps us know how much the index is at different ...
