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Kinematic analysis of the 3-RPR parallel manipulator  [PDF]
Damien Chablat,Philippe Wenger,Ilian Bonev
Computer Science , 2007,
Abstract: The aim of this paper is the kinematic study of a 3-RPR planar parallel manipulator where the three fixed revolute joints are actuated. The direct and inverse kinematic problem as well as the singular configuration is characterized. On parallel singular configurations, the motion produce by the mobile platform can be compared to the Reuleaux straight-line mechanism.
Research on Continuous Trajectory Tracking Control of Macro-Micro Manipulator System Based on Kinematic Compensation
运动学补偿的宏2微机器人连续轨迹控制研究

CHEN Qi-jun,WANG Yue-juan,CHEN Hui-tang,
陈启军
,王月娟,陈辉堂

控制理论与应用 , 2001,
Abstract: A small manipulator is attached at the tip of a large manipulator, this kind of system can be regarded as macro micro manipulator system. This paper presents a kind of novel control strategy of continuous trajectory tracking of macro micro manipulator system. Tracking errors of macro manipulator are compensated by the fast adjustment of micro manipulator and the control is implemented in joint space. Trajectory planning is completed off line and the kinematic redundancy of macro micro manipulator system is resolved by task augment. Simulation and experiment showed the efficiency of proposed method.
Kinematic Characteristics of 3-UPU Parallel Manipulator in Singularity and Its Application
Peng Binbin,Li Zengming,Wu Kai,Sun Yu
International Journal of Advanced Robotic Systems , 2011,
Abstract: This paper focuses on the kinematic characteristics of the 3‐UPU (universal‐prismatic‐ universal) parallel manipulator in one of singular configurations. The motion of the moving platform is analyzed by changing the layout of the universal joints. A layout of universal joints in the singular configuration is discussed in detail by deriving the kinematic and constraint equations. Solving the equations, the kinematic characteristics in such case is obtained. At the same time the kinematic characteristics is simulated by the commercial software and the results of the simulation verify it. Based on the kinematics characteristics of it, the application of the singular configuration is presented. And a compound limb which can translate freely along a circular path is presented. Finally, the some new 2‐DOF (degree of freedom) planar parallel translating manipulators whose orientation can remain constant are put forward by the compound limb. The passive joints of the new 2‐DOF planar parallel translating manipulators are universal joint and the struts of it do not bear the bending moment. It gives the planar parallel manipulator a good architecture to resist the force which is perpendicular to the kinematics plane.
The Kinematic Analysis of a Symmetrical Three-Degree-of-Freedom Planar Parallel Manipulator  [PDF]
Damien Chablat,Philippe Wenger
Computer Science , 2007,
Abstract: Presented in this paper is the kinematic analysis of a symmetrical three-degree-of-freedom planar parallel manipulator. In opposite to serial manipulators, parallel manipulators can admit not only multiple inverse kinematic solutions, but also multiple direct kinematic solutions. This property produces more complicated kinematic models but allows more flexibility in trajectory planning. To take into account this property, the notion of aspects, i.e. the maximal singularity-free domains, was introduced, based on the notion of working modes, which makes it possible to separate the inverse kinematic solutions. The aim of this paper is to show that a non-singular assembly-mode changing trajectory exist for a symmetrical planar parallel manipulator, with equilateral base and platform triangle.
Sensitivity Analysis of the Orthoglide, a 3-DOF Translational Parallel Kinematic Machine  [PDF]
Stéphane Caro,Philippe Wenger,Fouad Bennis,Damien Chablat
Computer Science , 2007,
Abstract: This paper presents a sensitivity analysis of the Orthoglide, a 3-DOF translational Parallel Kinematic Machine. Two complementary methods are developed to analyze its sensitivity to its dimensional and angular variations. First, a linkage kinematic analysis method is used to have a rough idea of the influence of the dimensional variations on the location of the end-effector. Besides, this method shows that variations in the design parameters of the same type from one leg to the other have the same influence on the end-effector. However, this method does not take into account the variations in the parallelograms. Thus, a differential vector method is used to study the influence of the dimensional and angular variations in the parts of the manipulator on the position and orientation of the end-effector, and particularly the influence of the variations in the parallelograms. It turns out that the kinematic isotropic configuration of the manipulator is the least sensitive one to its dimensional and angular variations. On the contrary, the closest configurations to its kinematic singular configurations are the most sensitive ones to geometrical variations.
The Kinematic design of a 3-dof Hybrid Manipulator  [PDF]
Damien Chablat,Philippe Wenger,Jorge Angeles
Computer Science , 2007,
Abstract: This paper focuses on the kinematic properties of a new three-degree-of-freedom hybrid manipulator. This manipulator is obtained by adding in series to a five-bar planar mechanism (similar to the one studied by Bajpai and Roth) a third revolute passing through the line of centers of the two actuated revolute joints of the above linkage. The resulting architecture is hybrid in that it has both serial and parallel links. Fully-parallel manipulators are known for the existence of particularly undesirable singularities (referred to as parallel singularities) where control is lost [4] and [6]. On the other hand, due to their cantilever type of kinematic arrangement, fully serial manipulators suffer from a lack of stiffness and from relatively large positioning errors. The hybrid manipulator studied is intrinsically stiffer and more accurate. Furthermore, since all actuators are located on the first axis, the inertial effects are considerably reduced. In addition, it is shown that the special kinematic structure of our manipulator has the potential of avoiding parallel singularities by a suitable choice of the "working mode", thus leading to larger workspaces. The influence of the different structural dimensions (e.g. the link lengths) on the kinematic and mechanical properties are analysed in view of the optimal design of such hybrid manipulators.
Multiobjective Optimum Design of a 3-RRR Spherical Parallel Manipulator with Kinematic and Dynamic Dexterities
Guanglei Wu
Modeling, Identification and Control , 2012, DOI: 10.4173/mic.2012.3.3
Abstract: This paper deals with the kinematic synthesis problem of a 3-underlineRRR spherical parallel manipulator, based on the evaluation criteria of the kinematic, kinetostatic and dynamic performances of the manipulator. A multiobjective optimization problem is formulated to optimize the structural and geometric parameters of the spherical parallel manipulator. The proposed approach is illustrated with the optimum design of a special spherical parallel manipulator with unlimited rolling motion. The corresponding optimization problem aims to maximize the kinematic and dynamic dexterities over its regular shaped workspace.
Kinematic and Dynamic Analyses of the Orthoglide 5-axis  [PDF]
Raza Ur-Rehman,Stéphane Caro,Damien Chablat,Philippe Wenger
Computer Science , 2008,
Abstract: This paper deals with the kinematic and dynamic analyses of the Orthoglide 5-axis, a five-degree-of-freedom manipulator. It is derived from two manipulators: i) the Orthoglide 3-axis; a three dof translational manipulator and ii) the Agile eye; a parallel spherical wrist. First, the kinematic and dynamic models of the Orthoglide 5-axis are developed. The geometric and inertial parameters of the manipulator are determined by means of a CAD software. Then, the required motors performances are evaluated for some test trajectories. Finally, the motors are selected in the catalogue from the previous results.
Virtual kinematic chains to solve the underwater vehicle-manipulator systems redundancy
Santos, Carlos H. F. dos;Guenther, Raul;Martins, Daniel;De Pieri, Edson R.;
Journal of the Brazilian Society of Mechanical Sciences and Engineering , 2006, DOI: 10.1590/S1678-58782006000300014
Abstract: this paper addresses the kinematics of the underwater vehicle-manipulator systems (uvmss). due the adittional degrees of freedom (dofs) provided by the vehicle, such systems are kinematically redundant, i.e. they possess more dofs than those required to execute a given task, and need to be solved using some redundancy technique. we present an approach based on introducing kinematic constraints. the approach uses the screw representation of movement and is based on the so-called davies method used to solve the kinematics of closed kinematic chains. we describe the vehicle-manipulator system as an open-loop chain and present a virtual kinematic chain concept that allows closing this open chain. applying the davies method to this resulting closed chain, the uvms direct kinematic is solved. the inverse kinematics is obtained using the same approach, by introducing extra constraints derived from energy savings requirements. the proposed approach is compared to another redundancy resolution method to illustrate the ability of the proposed strategy.
Virtual kinematic chains to solve the underwater vehicle-manipulator systems redundancy  [cached]
Santos Carlos H. F. dos,Guenther Raul,Martins Daniel,De Pieri Edson R.
Journal of the Brazilian Society of Mechanical Sciences and Engineering , 2006,
Abstract: This paper addresses the kinematics of the Underwater Vehicle-Manipulator Systems (UVMSs). Due the adittional degrees of freedom (dofs) provided by the vehicle, such systems are kinematically redundant, i.e. they possess more dofs than those required to execute a given task, and need to be solved using some redundancy technique. We present an approach based on introducing kinematic constraints. The approach uses the screw representation of movement and is based on the so-called Davies method used to solve the kinematics of closed kinematic chains. We describe the vehicle-manipulator system as an open-loop chain and present a virtual kinematic chain concept that allows closing this open chain. Applying the Davies method to this resulting closed chain, the UVMS direct kinematic is solved. The inverse kinematics is obtained using the same approach, by introducing extra constraints derived from energy savings requirements. The proposed approach is compared to another redundancy resolution method to illustrate the ability of the proposed strategy.
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