scholarly journals Workspace Identification of Stewart Platform

2020 ◽  
Vol 9 (3) ◽  
pp. 1903-1907
Keyword(s):  
Stewart Platform ◽  
Inverse Kinematic ◽  
Kinematic Modeling ◽  
Piston Motion ◽  
Platform Motion ◽  
Cylinder Piston ◽  
Moving Platform ◽  
The Individual ◽  
Platform Motions

The workspace identification of 6-DOF Stewart Platform has been done in this paper through inverse kinematic modeling. This Stewart Platform has six linear cylinder–piston actuators connected within fixed and the moving platform. The motions of the moving platform such as surge, sway, heave, roll, pitch and yaw have been generated from the combined motions of piston of actuators. The mathematical formulations for Inverse-Kinematic modeling of Stewart Platform have been formulated to find out the individual piston motion for the required platform motion. The platform motions and the actuator motions have been studied for the workspace identification of the Stewart Platform.

scholarly journals Design and Analysis of a Flexible, Elastic, and Rope-Driven Parallel Mechanism for Wrist Rehabilitation

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Zaixiang Pang ◽  
Tongyu Wang ◽  
Junzhi Yu ◽  
Shuai Liu ◽  
Xiyu Zhang ◽  
...  
Keyword(s):  
Inverse Kinematics ◽  
Parallel Mechanism ◽  
Inverse Kinematic ◽  
Parallel Structure ◽  
Flexible Joints ◽  
Rehabilitation Robots ◽  
Hybrid Mechanism ◽  
Compression Spring ◽  
Moving Platform

This paper proposes a bionic flexible wrist parallel mechanism to simulate human wrist joints, which is characterized by a rope-driven, compression spring-supported hybrid mechanism. Specifically, to realize the movement of the wrist mechanism, a parallel structure is adopted to support the mobile platform and is controlled by a cable, which plays the role of wrist muscles. Because the compression spring is elastic, it is difficult to directly solve inverse kinematics. To address this problem, the external force acting on the moving platform is firstly equivalent to the vector force and torque at the center of the moving platform. Then, based on inverse kinematic and static analyses, the inverse motion of the robot model can be solved according to the force and torque balance conditions and the lateral spring bending equation of the compression spring. In order to verify the proposed method, kinematics, statics, and parallel mechanism workspace are further analyzed by the software MATLAB. The obtained results demonstrate the effectiveness and feasibility of the designed parallel mechanism. This work offers new insights into the parallel mechanism with flexible joints in replicating the movements of the human wrist, thus promoting the development of rehabilitation robots and rope-driven technology to some extent.

Research on Inverse Kinematic Design of a Certain Hydraulic Stewart Platform

2011 ◽  
Vol 58-60 ◽  
pp. 2442-2445
Author(s):  
Zhi Yong Qu ◽  
Zheng Mao Ye
Keyword(s):  
Machine Tools ◽  
Stewart Platform ◽  
Inverse Kinematic ◽  
Design And Optimization ◽  
Kinematic Design ◽  
Structural Rigidity ◽  
The Future ◽  
Stewart Platforms ◽  
Kinematic Loop ◽  
Motion Dynamics

Stewart platforms have recently attracted attention as simulator and machine tools because of their conceptual potentials in high motion dynamics and accuracy combined with high structural rigidity due to their closed kinematic loop. This paper, composed of inverse kinematic design and optimization, attempts to ground the foundation on dynamics design and choice in the future.

Sensitivity analysis of a six degrees of freedom displacement measuring device

2013 ◽  
Vol 228 (1) ◽  
pp. 158-168 ◽  
Author(s):  
Andrea Mura
Keyword(s):  
Sensitivity Analysis ◽  
Performance Analysis ◽  
Degrees Of Freedom ◽  
Stewart Platform ◽  
Inverse Kinematic ◽  
Measuring Device ◽  
Six Degrees Of Freedom ◽  
Geometrical Characteristics

Object of this paper is the performance analysis of a six degrees of freedom measuring device based on a modified Stewart platform structure. Because of the device studied in this work represents a novel application of a Stewart like platform, an investigation about its performance has been done, in order to evaluate both behaviour and characteristics of this device in different geometrical configurations. In particular, sensitivity analysis has been carried on about geometrical characteristics and displacements amplitude. To calculate the sensitivity, the inverse kinematic equations of the device have been obtained.

Inverse Kinematic modeling of a class of continuum bionic handling arm

2014 ◽  
Author(s):  
Othman Lakhal ◽  
Achille Melingui ◽  
Abdelhakim Chibani ◽  
Coralie Escande ◽  
Rochdi Merzouki
Keyword(s):  
Inverse Kinematic ◽  
Kinematic Modeling

Grasshopper Knee Joint – Inverse Kinematic Modeling and Simulation of Ionic Polymer Metal Composites (IPMC) Actuators

2014 ◽  
Vol 19 ◽  
pp. 1-11 ◽  
Author(s):  
Muhammad Farid ◽  
Zhao Gang ◽  
Tran Linh Khuong ◽  
Zhuang Zhi Sun ◽  
Naveed Ur Rehman
Keyword(s):  
Knee Joint ◽  
Low Voltage ◽  
Kinematic Model ◽  
Inverse Kinematic ◽  
Kinematic Modeling ◽  
Ionic Polymer ◽  
Wolfram Mathematica ◽  
Polymer Metal ◽  
Transcendental Functions ◽  
Simulation Results

Biomimetic is the field of engineering in which biological structures and functions are analyzed and are used as the basis for the design and manufacturing of machines. Insects are the most populated creature and present everywhere in the world and can survive the most hostile environmental situations. IPMC is a smart material which has exhibited a significant bending and tip force after the application of a low voltage. It is light-weighted, flexible, easily actuated, multi-directional applicable and requires simple manufacturing.In this paper,five different contributions are made. Firstly, a two link grasshopper knee joint physical model is presented in which the actuation force required for moving the knee is provided by the IPMC material. This material constitutes one link of the linkage. Secondly,inverse kinematic modelhas been developed for the linkage. Thirdly, the system of equations is solved by proposing solutions to the known transcendental functions with unknown coefficients. Fourthly, wolfram mathematica is employed for thesimulationof the model. Finally,angles, velocity and accelerationof the links are analyzed based on the simulation results. The simulation results show that the tibia is displaying a lag in time from the femur verifying that it is operated by the force provided by the femur (IPMC). Also, it verified the flexible nature of the IPMC material through multiple peaks and troughs in the graphs. The angles range of the tibia is found quite admirable and it is believed that the IPMC material can add a new horizon to the manufacturing of small biomimetic equipment and low force actuated manipulators.

Kinematic Modeling and Error Analysis for a 3DOF Parallel-Link Coordinate Measuring Machine

2006 ◽  
Vol 532-533 ◽  
pp. 313-316 ◽  
Author(s):  
De Jun Liu ◽  
Hua Qing Liang ◽  
Hong Dong Yin ◽  
Bu Ren Qian
Keyword(s):  
Kinematic Model ◽  
Coordinate Measuring Machine ◽  
Inverse Kinematic ◽  
Differential Method ◽  
Error Model ◽  
Structural Parameter ◽  
Kinematic Modeling ◽  
Position Errors ◽  
Measuring Machine ◽  
Parallel Link

First, the forward kinematic model, the inverse kinematic model and the error model of a kind of coordinate measuring machine (CMM) using 3-DOF parallel-link mechanism are established based on the spatial mechanics theory and the total differential method, and the error model is verified by computer simulation. Then, the influence of structural parameter errors on probe position errors is systematically considered. This research provides an essential theoretical basis for increasing the measuring accuracy of the parallel-link coordinate measuring machine. It is of particular importance to develop the prototype of the new measuring equipment.

scholarly journals Kontrol Keseimbangan Robot Hexapod EILERO menggunakan Fuzzy Logic

2021 ◽  
Vol 9 (3) ◽  
pp. 533
Author(s):  
IWAN KURNIANTO WIBOWO ◽  
DANY PREISTIAN ◽  
FERNANDO ARDILLA
Keyword(s):  
Fuzzy Logic ◽  
Steady State ◽  
Balance Control ◽  
Inverse Kinematic ◽  
Hexapod Robot ◽  
Kinematic Modeling ◽  
Inclined Plane ◽  
Balance System ◽  
Data Feedback ◽  
Pitch Tilt

ABSTRAKPenelitian dengan topik robot hexapod telah banyak dikembangkan, namun sampai saat ini masih sedikit yang mengulas tentang kontrol keseimbangannya. Permasalahan yang kerap muncul adalah ketika robot berada dalam bidang miring, robot dapat terjatuh jika robot tidak dapat menyeimbangkan badan. Begitu pula dengan robot hexapod EILERO yang telah kami bangun. Untuk mengatasi permasalahan itu, selain pemodelan kinematik dan kinematika terbalik yang tepat, juga diperlukan suatu sistem keseimbangan yang baik. Dalam penelitian ini, kami menggunakan fuzzy logic untuk mengontrol keseimbangan robot EILERO dengan umpan balik data kemiringan dari sebuah sensor IMU. Setelah melalui beberapa pengujian yang komprehensif, didapatkan hasil bahwa robot dapat menyeimbangkan diri pada kondisi kemiringan papan pijakan antara -15° dan 15° pada orientasi kemiringan roll dan pitch. Robot mampu merespon dengan capaian steady state di bawah 3000 ms. Dengan demikian, robot EILERO semakin stabil dalam melintasi bidang yang tidak datar.Kata kunci: hexapod, EILERO, kinematika terbalik, fuzzy logic ABSTRACTResearch on the topic of the hexapod robot has been developed a lot, but until now there is little that has been discussed about balance control. The problem that often arises is that when the robot is on an inclined plane, the robot can fall if the robot cannot balance its body. Likewise with the EILERO hexapod robot that we have built. To solve this problem, besides proper kinematic modeling and inverse kinematic modeling, a good balance system is also needed. In this study, we used fuzzy logic to control the balance of the EILERO robot, with tilt data feedback from an IMU sensor. After going through several comprehensive tests, the results show that the robot can balance itself on the slope of the stepboards between -15 ° and 15 ° in the orientation of roll and pitch tilt. The robot is able to respond with steady state achievements below 3000 ms. Thus, the EILERO robot is increasingly stable in traversing uneven planes.Keywords: hexapod, EILERO, inverse kinematic, fuzzy logic

scholarly journals A Translational Three-Degrees-of-Freedom Parallel Mechanism With Partial Motion Decoupling and Analytic Direct Kinematics

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Huiping Shen ◽  
Damien Chablat ◽  
Boxiong Zeng ◽  
Ju Li ◽  
Guanglei Wu ◽  
...  
Keyword(s):  
Parallel Mechanism ◽  
Design Theory ◽  
Degrees Of Freedom ◽  
Analytic Solutions ◽  
Inverse Kinematic ◽  
Kinematic Modeling ◽  
Topological Design ◽  
Prismatic Joints ◽  
Topological Characteristics ◽  
Three Degrees Of Freedom

Abstract According to the topological design theory and the method of parallel mechanism (PM) based on position and orientation characteristic (POC) equations, this paper studied a three-degrees-of-freedom (3-DOF) translational PM that has three advantages, i.e., (i) it consists of three fixed actuated prismatic joints, (ii) the PM has analytic solutions to the direct and inverse kinematic problems, and (iii) the PM is of partial motion decoupling property. First, the main topological characteristics, such as the POC, degree-of-freedom, and coupling degree, were calculated for kinematic modeling. Thanks to these properties, the direct and inverse kinematic problems can be readily solved. Further, the conditions of the singular configurations of the PM were analyzed, which corresponds to its partial motion decoupling property.

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