scholarly journals Torque Reduction of a Reconfigurable Spherical Parallel Mechanism Based on Craniotomy Experimental Data

2021 ◽  
Vol 11 (14) ◽  
pp. 6534
Author(s):  
Terence Essomba ◽  
Juan Sandoval ◽  
Med Amine Laribi ◽  
Chieh-Tsai Wu ◽  
Cyril Breque ◽  
...  

This paper deals with a robotic manipulator dedicated to craniotomy with a remote center of motion based on a Spherical Parallel Manipulator (SPM) architecture. The SPM is proposed to handle the drilling tool through the requested craniotomy Degrees of Freedom (DoF) with two rotations. The proposed architecture allows one degree of redundancy according to the total DoF. Thus, a first contribution of this work focuses on the experimental analysis of craniotomy surgery tasks. Secondly, its behavior is improved, taking advantage of the redundancy of the SPM using the spinning motion as a reconfiguration variable. The spinning angle modulation allows the reconfigurable manipulator to minimize its motor torques. A series of motion capture and force experimentations is performed for the analysis of the kinematic and force interaction characterizing Burr hole craniotomy procedures. Experimentations were carried out by a neurosurgeon on a human cadaver, ensuring highly realistic conditions.

Robotica ◽  
2014 ◽  
Vol 34 (3) ◽  
pp. 671-686 ◽  
Author(s):  
T. Essomba ◽  
M. A. Laribi ◽  
S. Zeghloul ◽  
G. Poisson

SUMMARYThis paper introduces the design and the optimization of a probe holder robot for tele-echography applications. To define its kinematic architecture, an approach based on motion capture of an expert's gestures during ultrasound examinations was proposed. The medical gestures analyzed consisted of ultrasound probe movements and were used to characterize the kinematic specifications of the proposed manipulator. The selected architecture was a Spherical Parallel Mechanism (SPM) with 3 degrees of freedom (DoF) and its optimal synthesis was performed using real-coded Genetic Algorithms (GA). The optimization criteria and constraints were established thanks to the collaboration of medical experts and were successively formulated and solved using mono-objective and multi-objective functions.


Author(s):  
Yanwen Li ◽  
Yueyue Zhang ◽  
Lumin Wang ◽  
Zhen Huang

This paper investigates a novel 4-DOF 3-RRUR parallel manipulator, the number and the characteristics of its degrees of freedom are determined firstly, the rational input plan and the invert and forward kinematic solutions are carried out then. The corresponding numeral example of the forward kinematics is given. This type of parallel manipulators has a symmetrical structure, less accumulated error, and can be used to construct virtual-axis machine tools. The analysis in this paper will play an important role in promoting the application of such manipulators.


Robotica ◽  
2010 ◽  
Vol 29 (7) ◽  
pp. 1093-1100 ◽  
Author(s):  
Dan Zhang ◽  
Fan Zhang

SUMMARYIn this paper, we propose a unique, decoupled 3 degree-of-freedom (DOF) parallel wrist. The condition required for synthesizing a fully isotropic parallel mechanism is obtained on the basis of the physical meaning of the row vector in the Jacobian matrix. Specifically, an over-constrained spherical 3-DOF parallel mechanism is presented and the modified structure, which avoids the redundant constraints, is also introduced. The proposed manipulator is capable of decoupled rotational motions around the x, y, and z axes and contains an output angle that is equal to the input angle. As this device is analyzed with the Jacobian matrix, the mechanism is free of singularity within its workspace and maintains homogenous stiffness over the entire workspace.


Robotica ◽  
2015 ◽  
Vol 34 (9) ◽  
pp. 2056-2070 ◽  
Author(s):  
Po-Chih Lee ◽  
Jyh-Jone Lee

SUMMARYThis paper investigates the kinematics of one new isoconstrained parallel manipulator with Schoenflies motion. This new manipulator has four degrees of freedom and two identical limbs, each having the topology of Cylindrical–Revolute–Prismatic–Helical (C–R–P–H). The kinematic equations are derived in closed-form using matrix algebra. The Jacobian matrix is then established and the singularities of the robot are investigated. The reachable workspaces and condition number of the manipulator are further studied. From the kinematic analysis, it can be shown that the manipulator is simple not only for its construction but also for its control. It is hoped that the results of the evaluation of the two-limb parallel mechanism can be useful for possible applications in industry where a pick-and-place motion is required.


2018 ◽  
Vol 7 (4.10) ◽  
pp. 90 ◽  
Author(s):  
Arockia Selvakumar A ◽  
. .

This paper presents a numerical approach on kinematic analysis of 3-DOF parallel manipulator (PM). The proposed mechanisms constitute of PRS (Prismatic-Revolute-Spherical) parallel mechanism with two rotations and one translation. The forward and inverse kinematic equations of the PM are derived by position vector method. A total of 48 solutions are obtained for the forward kinematic equations using MATLAB. 


Robotica ◽  
2011 ◽  
Vol 29 (7) ◽  
pp. 1109-1116 ◽  
Author(s):  
Dan Zhang ◽  
Fan Zhang

SUMMARYIn this paper, we propose a unique, 3 degree-of-freedom (DOF) parallel wrist. Specifically, an over-constrained spherical 3-DOF parallel mechanism is presented and the modified structure, which avoids the redundant constraints, is also introduced.


Author(s):  
L-P Wang ◽  
J-S Wang ◽  
J Chen

The article presents the inverse dynamics of a two-degrees-of-freedom planar parallel manipulator by the Newton-Euler approach. On the basis of the inverse dynamic model, the driving forces of actuators are simulated in different motion parameters. Further, the effects of inertia of each moving component to the driving forces are computed through the numerical method.


Author(s):  
M. A. Laribi ◽  
T. Essomba ◽  
S. Zeghloul ◽  
G. Poisson

This paper considers the practice of a tele-echography through a new slave holder robot for a remote echographic diagnostic application. This robot is integrated in a master-slave system called ‘Robotic Platform for an Interactive Tele-echographic System’ (PROSIT ANR French national project). The proposed approach is based on motion capture of an expert’s gestures during the echography examination. The medical gestures were analyzed in terms of positions and velocities; the result has been used in the definition of the kinematics specifications of the proposed manipulator. The effective workspace size of a standard echography act, done by the medical expert, is determined through an experimental study. The evaluation of the workspace is based on the use of the Vicon Nexus motion capture system. The spherical parallel mechanism (SPM) has been selected because of its characteristics meeting the constraint requirements. In addition this architecture offers an excellent stiffness, high precision and is light weight. The design problem of a new parallel probe-holder robot according to the identified experimental workspace for the tele-echography system is presented. In this work, in order to increase the workspace volume of the manipulator, a minimal set of geometrical parameters of spherical parallel manipulators are optimized to find the maximum workspace. Seven independent design parameters have been identified. The optimal synthesis of spherical parallel manipulators is performed using a real-coded genetic algorithm (GA) based method. An optimal study of the orientation workspace is also presented.


2015 ◽  
Vol 758 ◽  
pp. 71-76
Author(s):  
Syamsul Huda ◽  
Syafri ◽  
Mulyadi Bur

In this paper was observed performances of developed three degrees of freedom (dof) parallel mechanism named 3-URU spherical parallel mechanism. The mechanism is composed of three identical limbs mounted symmetrically to base (fixed link) and platform (output link). The limb is constructed by universal-revolute and universal joints. The kinematic constants of mechanism consisting of link lengths, radius of platform, radius of base, mounting angle of limb and platform to base and platform were determined with consideration of velocity transmission and force constraint indices. To evaluate performance of mechanism, it was manufactured a prototype of mechanism designed base on these two mentioned indices. There are three steps proposed to realize the mechanism, (i) kinematic synthesis to determine of kinematic constants, (ii) design of mechanical components to define shape and dimension of links and joints by considering collision in wokingspace and static analysis, (iii) evaluation of mechanism performances consisting of workingspace, controllability of platform motion and static payload. Based on obtained results, it can be clarified that, the mechanism can produce spherical motion of platform which rotates on steady point recognized as center of platform rotation. The platform can achieve maximum inclination angle, 80 degree and at this posture occurs translational error, 0.0102 mm. On the other hand, the mechanism can support payload ten times of weight of moving parts.


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