This paper aims (i) to introduce a new monolithic micromanipulation system for applications requiring micro/nano scale planar motion, and (ii) to model its stiffness consisting of the inherent stiffness of its joints,...
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This paper aims (i) to introduce a new monolithic micromanipulation system for applications requiring micro/nano scale planar motion, and (ii) to model its stiffness consisting of the inherent stiffness of its joints, and the artificial stiffness due to its joint space position controller in order to obtain a decoupled compliant motion for the manipulator end point while a Cartesian force vector is acting upon it. The micromanipulation system is an in-parallel actuated planar manipulator based on five single DOF flexure joints connecting five supposedly rigid links to each other. Numerical results provided show that there exist practical operation ranges of the manipulator yielding both a suitable set of joint serve gains as well as a diagonal Cartesian stiffness matrix. The stiffness model can be used to predict the reaction forces arising from part misalignment and the task forces during the execution of micro tasks, such as micromanufacturing and microassembly. The determination of the forces is also useful for many applications such as designing micro fixtures and micro end effectors sustainable to task forces.
This paper addresses kinematic analysis and constrained structural optimisation of a five-bar planar parallel manipulator articulated with revolute joints only. The kinematics of the manipulator is investigated, and i...
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This paper addresses kinematic analysis and constrained structural optimisation of a five-bar planar parallel manipulator articulated with revolute joints only. The kinematics of the manipulator is investigated, and its Jacobian matrix as a function of the input joint positions has been formulated. An objective function based on minimizing the overall deviation of the condition number of the manipulator Jacobian matrix from the ideal condition number throughout the workspace of the manipulator has been employed to determine the link lengths subjected to a set of optimisation constraints. Optimisation results indicate that the proposed optimisation method is systematic, versatile and easy to implement for the optimal synthesis of the five-bar parallel manipulator and other kinematic chains.
This paper deals with the sequential inverse kinematics for the high speed tracking of flexible robots. As a continuation of the implicit expansion method in, the explicit version of the sequential inverse kinematics ...
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ISBN:
(纸本)0780378601
This paper deals with the sequential inverse kinematics for the high speed tracking of flexible robots. As a continuation of the implicit expansion method in, the explicit version of the sequential inverse kinematics is presented which is easier to be understood conceptually. The accuracy and stability of the two algorithms are compared and proved. Numerical study verifies the validity of the theoretical results.
GVG has been effectively used as a sensor based navigation tool using 360/spl deg/ sensor data. For mobile guide robot applications, however, we can only use 180/spl deg/ sensor data and the robustness of the navigati...
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ISBN:
(纸本)0780378601
GVG has been effectively used as a sensor based navigation tool using 360/spl deg/ sensor data. For mobile guide robot applications, however, we can only use 180/spl deg/ sensor data and the robustness of the navigation algorithm is critical for successful applications. For that purpose, the robot should be equipped with three capabilities. Those are 1) incremental GVG construction, 2) robust GVG navigation and 3) navigation strategy that just uses half of the sensor scan, i.e. 180/spl deg/. In this paper, we propose a GVG navigation algorithm that has above 3 capabilities. We firstly propose a method that can estimate the invisible 180/spl deg/ range from previous range data. Moreover, we suggest a way of robust GVG navigation algorithm by using a sensor data matching technique. The simulation result validates that the proposed algorithm can incrementally and robustly navigate the semi-unstructured map by using 180/spl deg/ sensor scan.
In this paper, basic models and a formulation are presented for the stiffness analysis of the humanoid robot WABIAN-RV. An evaluation of stiffness performances is carried out by numerically implementing the proposed f...
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A recently proposed method for stabilizing haptic interfaces and teleoperation systems was tested with a "PHANToM" commercial haptic device. The "passivity observer" (PO) and "passivity contro...
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A recently proposed method for stabilizing haptic interfaces and teleoperation systems was tested with a "PHANToM" commercial haptic device. The "passivity observer" (PO) and "passivity controller" (PC) stabilization method was formed to stabilize the system but also excite high frequency mode in the device. To solve this problem, we propose a method to use a time-varying desired energy threshold instead of fixed zero energy threshold for the PO, and make the actual energy input follow the time-varying energy threshold. With the time-varying energy threshold, we make the PC control action smooth without sudden impulsive behavior by distributing the dissipation. The proposed new PO/PC approach is applied to PHANToM with high stiffness (K=500 N/m), and stable and smooth contact is guarantee. Resetting and active environment display problems can also be solved with the reference energy following idea.
In this paper a modification of the time domain passivity controller is presented to improve its performance and transparency in case of multi degrees of freedom (dof) haptic interaction. In multi-dof application the ...
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In this paper a modification of the time domain passivity controller is presented to improve its performance and transparency in case of multi degrees of freedom (dof) haptic interaction. In multi-dof application the concept needs to be extended by additional conditions to distribute the adaptive damping appropriately among the degrees of freedom. This can be solved by using the geometrical information coded in the output signals of the system. Experiments show the validity of this concept.
This paper addresses the problem of motion planning for free-flying robots. Full state actuation is considered to allow for large displacements of the spacecraft. Motion planning is formulated as an optimization probl...
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This paper addresses the problem of motion planning for free-flying robots. Full state actuation is considered to allow for large displacements of the spacecraft. Motion planning is formulated as an optimization problem and kinematic as well as dynamic constraints are considered. The chosen optimization criteria are spacecraft actuation and final time. The proposed method allows solutions which do not require any spacecraft actuation for those end goals for which the robot motion is sufficient.
In this paper a biped locomotor, named as WL-15 (Waseda Leg 15), is analyzed in terms of stiffness characteristics. Basic models and a formulation are proposed in order to deduce the stiffness matrix as a function of ...
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All mobile robots suffer from odometry error. Relative localization from odometry has both the systematic and the non-systematic errors. However, once a precise system error model and its parameters are given, the acc...
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All mobile robots suffer from odometry error. Relative localization from odometry has both the systematic and the non-systematic errors. However, once a precise system error model and its parameters are given, the accuracy of odometry can be remarkably improved. Most previous works on this effort focused on the differential drive robots with little attention to the other types of mobile bases. In this paper, we analyze sources of odometry error and propose an error model for the synchro drive robot. We then describe a novel procedure to accurately estimate the error parameters of the derived error model and the covariance matrix of the synchro drive robot. However, this procedure is general for all mobile bases, so we also apply our method for the differential drive robots and show experiments. This new process uses the shape of the path, as opposed to just end points, to estimate the error parameters and covariance matrix. We happen to use the generalized Voronoi graph to generate this path. Experimental results validate the error model of the synchro drive robot and precise estimation ability of the proposed method for the synchro and the differential drive robots.
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