PAMINSA: A new family of partially decoupled parallel manipulators (original) (raw)
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PAMINSA: a New Family of Decoupled Parallel Manipulators
HAL (Le Centre pour la Communication Scientifique Directe), 2009
In this paper, a new family of parallel manipulators called PAMINSA is presented. The particularity of these manipulators is the decoupling of the displacements of the platform in the horizontal plane from its translation along the vertical axis. Such a decoupling allows the cancellation of the loads of gravity on the actuators which displace the platform in the horizontal plane. Parallel mechanisms from 3 to 6 degrees of freedom based on this property are systematized and the advantages of each are presented. The classification, singularity analysis and input torques optimization are then discussed. A prototype of the proposed manipulator with four degrees of freedom and experimental validations of the suggested concept are also presented. All obtained numerical simulations are approved by experimental tests.
On the Design of PAMINSA: A New Class of Parallel Manipulators With High-Load Carrying Capacity
Volume 8: 31st Mechanisms and Robotics Conference, Parts A and B, 2007
This paper deals with the new results concerning the topologically decoupled parallel manipulators called PAMINSA. The conceptual design of these manipulators, in which the copying properties of pantograph linkage are used, allows obtaining a large payload capability. A newly synthesized fully decoupled 3 degrees of freedom manipulator is discussed and a systematic approach for motion generation of input point of each limb is presented. It is shown that the conditions of complete static balancing of limbs are not effective in the case of dynamic mode of operation. This is approved by numerical simulations and experiments. A significant contribution of this paper is also the experimental validation of the suggested design concept. It is shown experimentally for the first time that the static loads on the rotating actuators, which displace the platform in the horizontal plane, are cancelled.
Robotica, 2015
SUMMARY Parallel manipulators (PMs) with decoupled kinematics can be obtained by combining a translational PM (TPM) with a spherical PM (SPM) either in multiplatform architectures or in integrated more-complex architectures. Some of the latter type are inspired by the 6–4 fully parallel manipulator (6–4 FPM), whereas others of the same type are deduced by suitably combining TPMs' limbs and SPMs' limbs into more cumbersome limbs which contain more than one actuated joint. The decoupled PMs (DPMs) presented here pursue an intermediate concept between the last two which keeps all the actuators on or near to the base in a simplified architecture with only three limbs. These features preserve the lightness of the mobile masses, together with the associated good-dynamic performances, and reduce the limitations on the workspace due to the eliminated limbs and to possible limb interferences. The finite and instantaneous kinematics of the proposed DPMs is studied, thus proving the pr...
Kinematic design of a family of 6-DOF partially decoupled parallel manipulators
2009
Parallel manipulators (PMs) with 6-DOF decoupled motion can simplify the manipulator kinematics and thus facilitate its motion planning and control. This paper studies the kinematic design of a family of partially decoupled parallel manipulators (DPMs) with 3-limb symmetrical structure, in which 3-DOF spatial motion composed of a vertical translation and two horizontal rotations can be independently controlled. The concept of group decoupling (GD) is introduced for classification and synthesis of decoupled motion PMs. Type synthesis of this manipulator family is carried out systematically based on GD and wrench system analysis. As a result, six DPM architectures, five of which are new, are obtained from this exercise. Instantaneous kinematics shows that the order of the Jacobian matrices of the newly found manipulator architectures can be reduced from six to three. The reduction of Jacobian order for the decoupled motion PMs facilitates analysis of manipulator singularity, displacement and statics. Hence, the approach can be utilized for decoupled PMs in other decoupled motion groups.
On the analysis of a new spatial three-degrees-of-freedom parallel manipulator
IEEE Transactions on Automation Science and Engineering, 2001
In this paper, a new spatial three-degrees-of-freedom (two degrees of translational freedom and one degree of rotational freedom) parallel manipulator is proposed. The parallel manipulator consists of a base plate, a movable platform, and three connecting legs. The inverse and forward kinematics problems are described in closed forms and the velocity equation of the new parallel manipulator is given. Three kinds of singularities are also presented. The workspace for the manipulator is analyzed systematically; in particular, indices to evaluate the mobility (in this paper, mobility means rotational capability) of the moving platform of the manipulator will be defined and discussed in detail. Finally, a topology architecture of the manipulator is introduced. The parallel manipulator has wide application in the fields of industrial robots, simulators, micromanipulators, and parallel machine tools.
Journal of Mechanical Design, 2008
In this paper, a new four degrees of freedom 3T1R parallel manipulator with high-load carrying capacity is presented. This manipulator generates Schönflies motions, in which the moving platform carries out three independent translations and one rotation about one axis of fixed orientation. The particularity of the proposed architecture is the decoupling of the displacements of the platform in the horizontal plane from the platform’s translation along the vertical axis. Such a decoupling allows the cancellation of the gravity loads on the actuators, which displace the platform in the horizontal plane. A prototype of the proposed manipulator with four degrees of freedom and an experimental validation of the suggested concept are also presented. Two cases have been examined on the built prototype: a manipulator with payload and one without. It was shown that the input torques of actuators displacing the platform in the horizontal plane for these two cases are the same; i.e., the payloa...
Partially Decoupled Parallel Manipulators Based on Multiple Platforms
The nonlinearity of the position equations of most parallel manipulators burdens the control and is a serious drawback for industrial applications. In this paper the authors have developed a 5 degrees of freedom parallel manipulator 3T2R whose position equations are explicit and partially decoupled. In order to get that, several platforms, partially actuated by limbs joined to the base, have been articulated together. This concept of a parallel assembly of parallel manipulators produces simple position equations, partially decoupled, high values of tilting angles, and a good stiffness.
Kinematics and singularity analyses of a 4-dof parallel manipulator using screw theory
Mechanism and Machine Theory, 2006
In this work, the kinematics and singularity analyses of a four degrees of freedom parallel manipulator are investigated using the theory of screws. As an initial step, the forward position analysis is carried out and forward position equations are obtained in a closed form, thanks to the simplicity of the architecture of the proposed mechanism. Afterwards, simple and compact expressions are derived for the velocity and reduced acceleration states of the moving platform w.r.t. the fixed coordinate frame of the manipulator, both in screw form, through each limb, and as six-dimensional vectors. The Klein form, a symmetrical bilinear form of the Lie algebra e(3), plays a central role in the present work. A numerical example is provided to demonstrate the efficacy of screw theory in efficiently analysing the kinematics and singularity of the parallel manipulator. The numerical results from the kinematic analysis are verified with results produced with a commercially available dynamic and kinematic simulation program.
A Three Degree of Freedom Parallel Manipulator with Only Translational Degrees of Freedom
1997
In this dissertation, a novel parallel manipulator is investigated. The manipulator has three degrees of freedom and the moving platform is constrained to only translational motion. The main advantages of this parallel manipulator are that all of the actuators can be attached directly to the base, closed-form solutions are available for the forward kinematics, the moving platform maintains the same orientation throughout the entire workspace, and it can be constructed with only revolute joints. Closed-form solutions for both the forward and inverse kinematics problems are presented. It is shown that the inverse kinematics problem has up to four real solutions, and the forward kinematics problem has up to 16 real solutions.