MBARS2: A New Design for a 3- Degrees of Freedom Parallel Structure for Joint Arthroplasty

2008 ◽  
Author(s):  
A. Wolf ◽  
S. Amir ◽  
A. B. Mor
Keyword(s):  
Coordinate System ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Joint Arthroplasty ◽  
Robotic System ◽  
Parallel Structure ◽  
Tracking Systems ◽  
Mechanical Structure ◽  
Workspace Analysis

In this report we present the second prototype of a 3-degrees-of-freedom active, miniature bone-attached, robotic system. The report focuses on the mechanical structure, workspace analysis and inverse kinematics solution. The robot is capable of preparing the bone cavity for an implant during joint arthroplasty procedures. This system, just as its predecessor is image-free and all planning is performed intraoperatively in the robot coordinate system, eliminating the need for external tracking systems in the OR. Experiments were conducted using the first robot prototype to evaluate its accuracy and the results supported the feasibility of the concept.

Orientation Workspace Analysis of a Novel 3SPS+1PS Symmetrical Parallel Manipulator Based on Unit Quaternion

2011 ◽  
Vol 201-203 ◽  
pp. 1849-1853
Author(s):  
Jing Li Yu ◽  
Gang Cheng ◽  
Shuai Zhang ◽  
De Kun Zhang
Keyword(s):  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Unit Quaternion ◽  
Structure Characteristics ◽  
Workspace Analysis ◽  
Moving Platform ◽  
Position And Orientation ◽  
4 Degrees Of Freedom ◽  
Orientation Workspace

For a novel 3SPS+1PS parallel manipulator with 4 degrees of freedom including three rotations and one translation, the formulae for solving the inverse kinematics equations are derived based on quaternion method. Unit quaternion is used to represent the position and orientation of moving platform, and the singularities caused by Euler angles are avoided. Combining the topological structure characteristics of the parallel manipulator, it only has three rotations when its moving platform is at a given translation position. Based on the inverse position/pose equations and the all the constraints of the parallel manipulator, the discrete algorithm for the orientation workspaces of 3SPS+1PS parallel manipulator where the moving platform is at some different given translation positions are designed. The research builds the theoretical basis for optimizing the orientation workspace with given position.

Spherical and Non-Spherical Combined Two Degree-of-Freedom Rotational Parallel Mechanism for a Microsurgical Robotic System

2018 ◽  
Vol 30 (6) ◽  
pp. 846-854
Author(s):  
Jumpei Arata ◽  
Yoshiteru Kobayashi ◽  
Ryu Nakadate ◽  
Shinya Onogi ◽  
Kazuo Kiguchi ◽  
...  
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
High Accuracy ◽  
Mechanical Tests ◽  
Robotic System ◽  
Parallel Structure ◽  
Small Vessels ◽  
Technical Requirements ◽  
Close Proximity ◽  
Two Degree Of Freedom

Microsurgery, often performed for anastomosis of small vessels and nerves, requires micro-manipulations of small tissues and thus requires highly specialized surgical skills. Robotic technology has great potential to assist with microsurgical treatments because of the high accuracy provided by robots; however, implementation remains challenging because the technical requirements of robotic surgery are far different from those in industry. One of the greatest challenges is that two surgical tools (e.g., tweezers) must be precisely and deftly moved around the surgical area in seven degrees of freedom (DOF) using one DOF to grasp each tool, and these tools are used in close proximity to each other. Additionally, high accuracy and rigidity at the tool tip are imperative for successful performance of the microsurgical procedure. In this study, we propose a new rotational two-DOF parallel mechanism that has the inherent advantages of a parallel mechanism, namely accuracy and rigidity, within a newly proposed spherical and non-spherical combined parallel structure to prevent collision of the two mechanisms in a dual-arm setup for microsurgery. The prototype was evaluated by performing a series of mechanical tests, and microsurgical suturing was performed by a microsurgical robotic system. The series of evaluations demonstrated the feasibility of the proposed mechanism.

Workspace Analysis and Mechanical Innovation of YWZ Dexterous Hand

2011 ◽  
Vol 338 ◽  
pp. 557-565 ◽  
Author(s):  
Wen Zhen Yang ◽  
Hua Zhang ◽  
Shi Guang Yu ◽  
Wen Hua Chen
Keyword(s):  
Degrees Of Freedom ◽  
Bone Structure ◽  
Experimental Results ◽  
Human Hand ◽  
Robot Hand ◽  
Coordinate Systems ◽  
Mechanical Structure ◽  
Workspace Analysis ◽  
Physical Prototype ◽  
Dexterous Hand

Degrees of freedom (DOFs) and workspace are important factors to evaluate the flexibility of the dexterous hand. This paper develops an original dexterous hand, which has 20 active DOFs and adjustable thumb. Imitating the human hand bone structure, we design a full driven multi-fingered anthropomorphic robot hand (YWZ dexterous hand). For the thumb of YWZ dexterous hand, we innovatively design a metacarpal phalange mechanical structure to adjust thumb’s assembly position and radial orientation relative the palm. We construct coordinate systems to deduce the finger kinematic equations and analyze the finger workspace. A physical prototype of YWZ dexterous hand was manufactured to test its kinematic characteristics and workspace. Experimental results validate the YWZ dexterous hand has large workspace, excellent operating flexibility.

Design and Analysis of Parallel Mechanism with Linear Drives Located on the Base at Specified Angles

2021 ◽  
pp. 41-48
Author(s):  
Y.V. Rodionov ◽  
A.N. Sukhostavskiy ◽  
A.A. Romanov ◽  
A.V. Dukhov ◽  
I.V. Pelin
Keyword(s):  
Coordinate System ◽  
Inverse Kinematics ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Kinematic Chain ◽  
Relative Movement ◽  
Structural Synthesis ◽  
Output Link ◽  
Constraint Equations ◽  
Inverse Kinematics Problem

The article considers a novel parallel mechanism with drives located on the base at different angles to its plane. This arrangement allows performing a relative movement between objects under water or in space (in aggressive environments). The new mechanism topology is compact for transportation and efficient for operation in aggressive environments. Structural synthesis has been performed; the number of degrees of freedom of the output link was calculated. A general approach to solving the inverse kinematics problem of positions is proposed and an example for a kinematic chain is shown. Denavit — Hartenberg matrices are used to solve the problem of positions. The position of the output link described by this matrix is used to represent the points of this link in the base coordinate system. The constraint equations are applied, which are the distances between the points of the base and the output link.

scholarly journals Design and kinematics analysis of a novel six-degree-of-freedom serial humanoid torso

2018 ◽  
Vol 15 (1) ◽  
pp. 172988141774812 ◽  
Author(s):  
Tao Li ◽  
Peng Yao ◽  
Minzhou Luo ◽  
Zhiying Tan ◽  
Meiling Wang ◽  
...  
Keyword(s):  
Inverse Kinematics ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Large Scale ◽  
Humanoid Robots ◽  
Degree Of Freedom ◽  
Chaos Optimization ◽  
Workspace Analysis ◽  
Forward Kinematic ◽  
Six Degree Of Freedom

This article presents a bioinspired humanoid torso which is supposed to be used as the trunk for humanoid robots. It can effectively mimic motions of human torso with high degrees of freedom, and it has high stiffness and easy-to-control features. The main structure of the proposed torso is a six-degree-of-freedom serial mechanism with twist angles that are not equal to 0, π/2 or π and zero-length links. Forward kinematic and workspace analysis based on Denavit–Hartenberg and Monte Carlo methods have been formulated to analyze the feasibility of this structure. In addition, a hybrid method combing the large-scale regularity search capabilities of chaos optimization and the quasi-Newton method with relatively high-speed convergence has been proposed to analyze inverse kinematics. Simulations are carried out with the aim to validate the correctness and efficiency of this method for studying the inverse kinematics.

Parallel and sequential structures of manipulators in robotic surgery

2019 ◽  
Vol 485 (2) ◽  
pp. 166-170
Author(s):  
E. I. Veliev ◽  
R. F. Ganiev ◽  
V. A. Glazunov ◽  
G. S. Filippov
Keyword(s):  
Robotic Surgery ◽  
Robotic System ◽  
Parallel Structure ◽  
Manipulation System ◽  
Surgical Manipulation ◽  
Surgical Operations

The problems of modern robotics associated with the requirements for devices designed for various purposes are considered. The daVinci robotic surgical manipulation system is analyzed. The developed robotic system with a parallel structure designed for various kinds of surgical operations is proposed.

Effects of Dynamic Model Errors in Task-Priority Operational Space Control

Robotica ◽  
2021 ◽  
pp. 1-12
Author(s):  
Paolo Di Lillo ◽  
Gianluca Antonelli ◽  
Ciro Natale
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Null Space ◽  
Control Algorithms ◽  
Model Errors ◽  
Operational Space ◽  
Dynamic Level ◽  
Concurrent Tasks ◽  
Modeling Errors

SUMMARY Control algorithms of many Degrees-of-Freedom (DOFs) systems based on Inverse Kinematics (IK) or Inverse Dynamics (ID) approaches are two well-known topics of research in robotics. The large number of DOFs allows the design of many concurrent tasks arranged in priorities, that can be solved either at kinematic or dynamic level. This paper investigates the effects of modeling errors in operational space control algorithms with respect to uncertainties affecting knowledge of the dynamic parameters. The effects on the null-space projections and the sources of steady-state errors are investigated. Numerical simulations with on-purpose injected errors are used to validate the thoughts.

Kinematic Analysis and Optimization of a Novel Robot for Surgical Tool Manipulation

2008 ◽  
Author(s):  
Xiaoli Zhang ◽  
Carl A. Nelson
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Force Feedback ◽  
Robotic Systems ◽  
Small Space ◽  
Surgical Robots ◽  
Tool Positioning ◽  
Rotation Axes ◽  
Surgical Tool ◽  
Linear Nature

The size and limited dexterity of current surgical robotic systems are factors which limit their usefulness. To improve the level of assimilation of surgical robots in minimally invasive surgery (MIS), a compact, lightweight surgical robotic positioning mechanism with four degrees of freedom (DOF) (three rotational DOF and one translation DOF) is proposed in this paper. This spatial mechanism based on a bevel-gear wrist is remotely driven with three rotation axes intersecting at a remote rotation center (the MIS entry port). Forward and inverse kinematics are derived, and these are used for optimizing the mechanism structure given workspace requirements. By evaluating different spherical geared configurations with various link angles and pitch angles, an optimal design is achieved which performs surgical tool positioning throughout the desired kinematic workspace while occupying a small space bounded by a hemisphere of radius 13.7 cm. This optimized workspace conservatively accounts for collision avoidance between patient and robot or internally between the robot links. This resultant mechanism is highly compact and yet has the dexterity to cover the extended workspace typically required in telesurgery. It can also be used for tool tracking and skills assessment. Due to the linear nature of the gearing relationships, it may also be well suited for implementing force feedback for telesurgery.

scholarly journals Finite-Horizon Kinetic Energy Optimization of a Redundant Space Manipulator

2021 ◽  
Vol 11 (5) ◽  
pp. 2346
Author(s):  
Alessandro Tringali ◽  
Silvio Cocuzza
Keyword(s):  
Kinetic Energy ◽  
Real Time ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Computational Time ◽  
Redundant Manipulators ◽  
Space Robotics ◽  
Optimal Method ◽  
End Effector ◽  
Global Optimal

The minimization of energy consumption is of the utmost importance in space robotics. For redundant manipulators tracking a desired end-effector trajectory, most of the proposed solutions are based on locally optimal inverse kinematics methods. On the one hand, these methods are suitable for real-time implementation; nevertheless, on the other hand, they often provide solutions quite far from the globally optimal one and, moreover, are prone to singularities. In this paper, a novel inverse kinematics method for redundant manipulators is presented, which overcomes the above mentioned issues and is suitable for real-time implementation. The proposed method is based on the optimization of the kinetic energy integral on a limited subset of future end-effector path points, making the manipulator joints to move in the direction of minimum kinetic energy. The proposed method is tested by simulation of a three degrees of freedom (DOF) planar manipulator in a number of test cases, and its performance is compared to the classical pseudoinverse solution and to a global optimal method. The proposed method outperforms the pseudoinverse-based one and proves to be able to avoid singularities. Furthermore, it provides a solution very close to the global optimal one with a much lower computational time, which is compatible for real-time implementation.

Workspace, dexterity and dimensional optimization of microhexapod

2015 ◽  
Vol 35 (4) ◽  
pp. 341-347 ◽  
Author(s):  
E. Rouhani ◽  
M. J. Nategh
Keyword(s):  
Degrees Of Freedom ◽  
Optimization Problem ◽  
Screw Theory ◽  
Design Parameters ◽  
Dimensional Synthesis ◽  
Content Type ◽  
Workspace Analysis ◽  
The Difference ◽  
Flexure Joints ◽  
6 Degrees Of Freedom

Purpose – The purpose of this paper is to study the workspace and dexterity of a microhexapod which is a 6-degrees of freedom (DOF) parallel compliant manipulator, and also to investigate its dimensional synthesis to maximize the workspace and the global dexterity index at the same time. Microassembly is so essential in the current industry for manufacturing complicated structures. Most of the micromanipulators suffer from their restricted workspace because of using flexure joints compared to the conventional ones. In addition, the controllability of micromanipulators inside the whole workspace is very vital. Thus, it is very important to select the design parameters in a way that not only maximize the workspace but also its global dexterity index. Design/methodology/approach – Microassembly is so essential in the current industry for manufacturing complicated structures. Most of the micromanipulators suffer from their restricted workspace because of using flexure joints compared to the conventional ones. In addition, the controllability of micromanipulators inside the whole workspace is very vital. Thus, it is very important to select the design parameters in a way that not only maximize the workspace but also its global dexterity index. Findings – It has been shown that the proposed procedure for the workspace calculation can considerably speed the required calculations. The optimization results show that a converged-diverged configuration of pods and an increase in the difference between the moving and the stationary platforms’ radii cause the global dexterity index to increase and the workspace to decrease. Originality/value – The proposed algorithm for the workspace analysis is very important, especially when it is an objective function of an optimization problem based on the search method. In addition, using screw theory can simply construct the homogeneous Jacobian matrix. The proposed methodology can be used for any other micromanipulator.

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