The semigraphical determination of all real inverse kinematic solutions of general six-revolute manipulators

2005 ◽  
pp. 23-32 ◽  
Author(s):  
Jorge Angeles ◽  
Kourosh E. Zanganeh
Keyword(s):  
Inverse Kinematic

Kinematic and Workspace Modelling of a 6-PUS Parallel Mechanism

2018 ◽  
Author(s):  
Jérôme Landuré ◽  
Clément Gosselin
Keyword(s):  
Kinematic Analysis ◽  
Parallel Mechanism ◽  
Inverse Kinematic ◽  
Degree Of Freedom ◽  
Accurate Description ◽  
Transmission Ratio ◽  
Inverse Kinematic Problem ◽  
Jacobian Matrices ◽  
Six Degree Of Freedom

This article presents the kinematic analysis of a six-degree-of-freedom six-legged parallel mechanism of the 6-PUS architecture. The inverse kinematic problem is recalled and the Jacobian matrices are derived. Then, an algorithm for the geometric determination of the workspace is presented, which yields a very fast and accurate description of the workspace of the mechanism. Singular boundaries and a transmission ratio index are then introduced and studied for a set of architectural parameters. The proposed analysis yields conceptual architectures whose properties can be adjusted to fit given applications.

Posture Prediction Versus Inverse Kinematics

2001 ◽  
Author(s):  
Karim Abdel-Malek ◽  
Wei Yu ◽  
Zan Mi ◽  
E. Tanbour ◽  
M. Jaber
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Human Performance ◽  
Inverse Kinematic ◽  
Cost Functions ◽  
Optimization Approach ◽  
Final Position ◽  
Serial Robot ◽  
Posture Prediction

Abstract Inverse kinematics is concerned with the determination of joint variables of a manipulator given its final position or final position and orientation. Posture prediction also refers to the same problem but is typically associated with models of the human limbs, in particular for postures assumed by the torso and upper extremities. There has been numerous works pertaining to the determination and enumeration of inverse kinematic solutions for serial robot manipulators. Part of these works have also been directly extended to the determination of postures for humans, but have rarely addressed the choice of solutions undertaken by humans, but have focused on purely kinematic solutions. In this paper, we present a theoretical framework that is based on cost functions as human performance measures, subsequently predicting postures based on optimizing one or more of such cost functions. This paper seeks to answer two questions: (1) Is a given point reachable (2) If the point is reachable, we shall predict a realistic posture. We believe that the human brain assumes different postures driven by the task to be executed and not only on geometry. Furthermore, because of our optimization approach to the inverse kinematics problem, models with large number of degrees of freedom are addressed. The method is illustrated using several examples.

Inverse Kinematics of Serial Redundant Manipulators With Locked Articulations

1995 ◽  
Author(s):  
Louis Perreault ◽  
Clément M. Gosselin
Keyword(s):  
Inverse Kinematics ◽  
General Procedure ◽  
Inverse Kinematic ◽  
Redundant Manipulators ◽  
Redundant Manipulator ◽  
Inverse Kinematic Problem

Abstract This paper presents an algorithm for the solution of the inverse kinematics of a serial redundant manipulator with one (or more) locked joint(s). To this end, a general procedure is developed for the determination of the equivalent Denavit-Hartenberg parameters of a serial manipulator with locked joints. This procedure can be applied to any serial architecture. The solution of the inverse kinematic problem for the three cases which can arise is then addressed. An example of the application of the method to a SARCOS 7-DOF manipulator is also given.

scholarly journals On determination of the permittivity through the module of the vector of the electric strength of the high-frequency electromagnetic field

2019 ◽  
Vol 484 (3) ◽  
pp. 269-272
Author(s):  
V. G. Romanov
Keyword(s):  
Inverse Problem ◽  
Electric Fields ◽  
High Frequency ◽  
Inverse Kinematic ◽  
Point Sources ◽  
Electric Strength ◽  
Inverse Kinematic Problem ◽  
High Frequency Electromagnetic Field ◽  
The Given

For nonmagnetic and nonconductive medium the system of electrodynamic equations that corresponds to periodic in time oscillations is considered. An inverse problem of determining permittivity in this system by the given module of the electric strength is studied. It is supposed that the electric fields is a result of the interference of two fields created by point sources. The permittivity e(x) is assumed to be differ from a given positive constant e0 inside of a compact domain W0 Ì R3 only. An information on module of the electric strength is given on the boundary of the domain W contained W0 inside itself and for all frequencies beginning with some fixed frequency w0. The asymptotic behavior of solution of a direct problem related to the electrodynamic equations is studied and the original inverse problem is reduced to the well known inverse kinematic problem. This reduction open a way for constructive solution of the inverse phaseless problem.

scholarly journals Utilization of multilayer perceptron for determining the inverse kinematics of an industrial robotic manipulator

2021 ◽  
Vol 18 (4) ◽  
pp. 172988142092528
Author(s):  
Sandi Baressi Šegota ◽  
Nikola Anđelić ◽  
Vedran Mrzljak ◽  
Ivan Lorencin ◽  
Ivan Kuric ◽  
...  
Keyword(s):  
Multilayer Perceptron ◽  
Inverse Kinematics ◽  
Absolute Error ◽  
Robotic Manipulator ◽  
Inverse Kinematic ◽  
Percentage Error ◽  
Joint Angles ◽  
Transformation Matrices ◽  
Error Metrics

Inverse kinematic equations allow the determination of the joint angles necessary for the robotic manipulator to place a tool into a predefined position. Determining this equation is vital but a complex work. In this article, an artificial neural network, more specifically, a feed-forward type, multilayer perceptron (MLP), is trained, so that it could be used to calculate the inverse kinematics for a robotic manipulator. First, direct kinematics of a robotic manipulator are determined using Denavit–Hartenberg method and a dataset of 15,000 points is generated using the calculated homogenous transformation matrices. Following that, multiple MLPs are trained with 10,240 different hyperparameter combinations to find the best. Each trained MLP is evaluated using the R 2 and mean absolute error metrics and the architectures of the MLPs that achieved the best results are presented. Results show a successful regression for the first five joints (percentage error being less than 0.1%) but a comparatively poor regression for the final joint due to the configuration of the robotic manipulator.

Kinematic Analysis and Singularity Loci of Spatial Four-Degree-of-Freedom Parallel Manipulators

1996 ◽  
Author(s):  
Jiegao Wang ◽  
Clément M. Gosselin
Keyword(s):  
Kinematic Analysis ◽  
Parallel Manipulators ◽  
Inverse Kinematic ◽  
Degree Of Freedom ◽  
Numerical Determination ◽  
Inverse Kinematic Problem ◽  
Flight Simulators ◽  
Important Design ◽  
Robotic Applications

Abstract The kinematic analysis and the determination of the singularity loci of spatial four-degree-of-freeedom parallel manipulators with prismatic or revolute actuators are discussed in this article. After introducing the architecture of the spatial parallel four-degree-of-freedom manipulators, algorithms for the solution of the inverse kinematic problem are provided for the two kinds of manipulators considered. Two different methods are presented for the derivation of the velocity equations and the corresponding Jacobian matrices are derived. The numerical determination of the workspace boundaries is then briefly discussed. Finally, the determination of the singularity loci is performed using the velocity equations and examples are given to illustrate the results obtained. Spatial four-degree-of-freedom parallel manipulators can be used in several robotic applications as well as in flight simulators. The determination of their singularity loci is a very important design issue.

Analysis and Design of a Spherical Micromechanism With Flexure Hinges

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Massimo Callegari ◽  
Alessandro Cammarata ◽  
Andrea Gabrielli ◽  
Maurizio Ruggiu ◽  
Rosario Sinatra
Keyword(s):  
Rigid Body ◽  
Inverse Dynamics ◽  
Inverse Kinematic ◽  
Rigid Body Dynamic ◽  
Analysis And Design ◽  
Rigid Body Model ◽  
Kinematic Analyses ◽  
Robotic Wrist ◽  
Body Dynamic

The article describes the design of a robotic wrist able to perform spherical motions: Its mechanical architecture is based on parallel kinematics and is suitable to be realized at the mini- or microscale by means of flexible joints. In view of the preliminary design, a rigid-body model has been studied first and the direct and inverse kinematic analyses have been performed, allowing for the determination of theoretical workspace and passive joints’ displacements. The rigid-body dynamic behavior and the operative ranges of the machine have been assessed through the development of an inverse dynamics model. Then, the microparts have been designed with the help of finite element method (FEM) and multibody software and the study has been focused on the flexures: Since the analyses showed that the center of the spherical motion moves around several millimeters in the workspace, the original kinematic concept has been modified with the introduction of a ball joint constraining the mobile platform to frame so as to prevent unwanted translations.

A Complete Solution for the Inverse Kinematic Problem of the General 6R Robot Manipulator

1991 ◽  
Vol 113 (4) ◽  
pp. 481-486 ◽  
Author(s):  
H. Y. Lee ◽  
C. Woernle ◽  
M. Hiller
Keyword(s):  
Robot Manipulator ◽  
Complete Solution ◽  
Kinematic Chain ◽  
Polynomial Equation ◽  
Inverse Kinematic ◽  
Inverse Kinematic Problem ◽  
End Effector ◽  
Polynomial Degree ◽  
Half Angle

The inverse kinematic problem of the general 6R robot manipulator is completely solved by means of a 16th degree polynomial equation in the tangent of the half-angle of a revolute joint. An algorithm is developed to compute the desired joint angles of all possible configurations of the kinematic chain for a given position of the end-effector. Examples for robots with maximal 16 different configurations show that the polynomial degree 16 is the lowest possible for the general 6R robot manipulator. Further, a numerical method for the determination of the boundaries of the workspace and its subspaces with different numbers of configurations is developed. These boundaries indicate the singular positions of the end-effector.

DETERMINATION OF THE ANALYTICAL WORKSPACE BOUNDARIES OF A NOVEL 2-DOF PLANAR TENSEGRITY MECHANISM

2010 ◽  
Vol 34 (1) ◽  
pp. 75-91 ◽  
Author(s):  
Marc Arsenault
Keyword(s):  
Weight Ratio ◽  
Inverse Kinematic ◽  
Degree Of Freedom ◽  
Analytical Expressions ◽  
Two Degree Of Freedom ◽  
High Payload

Tensegrity mechanisms are slowly emerging as potential alternatives to more conventional mechanisms for certain types of applications where a reduced inertia of the mobile parts and a high payload to weight ratio are sought. With this in mind, a two-degree-of-freedom planar tensegrity mechanism is developed using a simple actuation strategy to keep the mechanism in self-stressed configurations. Solutions to the mechanism’s direct and inverse kinematic problems are first developed and are then used to determine analytical expressions for its workspace boundaries.

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