Error Evaluation Method of Approximated Inverse Kinematics for Parallel-Wire Driven System – Basic Study for Three-Wire Planar System –

2016 ◽  
Vol 28 (6) ◽  
pp. 808-818 ◽  
Author(s):  
Hitoshi Kino ◽  
◽  
Nobuhiro Okubo ◽  
Toshihide Ikeda ◽  
Hiroaki Ochi ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Evaluation Method ◽  
Inverse Kinematic ◽  
Basic Study ◽  
Planar System ◽  
End Effector ◽  
Two Degrees Of Freedom ◽  
Parallel Wire ◽  
Positioning Errors ◽  
Driven System

[abstFig src='/00280006/04.jpg' width='300' text='Two-degrees-of-freedom planar system using three wires' ] Parallel-wire driven system, a kind of parallel-link mechanism, employs flexible and light wires in place of rigid links. By applying kinematics to parallel-wire driven systems, we seek to obtain the relationship between the end-effector’s position and wire length. Kinematics usually approximates the wire-contacting point of the winding reel (or guiding pulley) in the actuator unit to be a fixed point. Similar kinematic approximations, however, are likely to cause errors in controlling the end-effector position. In this study, therefore, we attempt to evaluate end-effector positioning errors due to inverse kinematic approximations. As the first step, we analyze end-effector positioning errors in two-degrees-of-freedom planar system and propose two methods to evaluate the positioning errors. Then, we conduct two case studies where we compare the errors due to inverse kinematic approximations and effects of wire’s elastic elements in order to confirm effectiveness of the proposed methods for evaluating end-effector positioning errors.

scholarly journals Error Analysis by Kinetics for Parallel-Wire Driven System Using Approximated Inverse Kinematics

2018 ◽  
Vol 30 (5) ◽  
pp. 763-771
Author(s):  
Hitoshi Kino ◽  
Takumi Imamura ◽  
Norimitsu Sakagami ◽  
◽  
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Target Object ◽  
Planar System ◽  
Positioning Control ◽  
Parallel Wire ◽  
Positioning Errors ◽  
Driven System ◽  
The Wire

Parallel-wire driven systems, which use light flexible wires in place of rigid links, control the position of a target object by controlling their wire lengths. In the kinematics for such a parallel-wire driven system, when the relationship between the end-effector position and the wire lengths is investigated, a fixed point for the wire-contacting point on the winding reel in the actuator (or guide pulley) is often approximated to simplify the calculation. The approximated kinematics however could lead to a number of positioning errors in the positioning control. This study proposes a framework for evaluating these positioning control errors by using approximated inverse kinematics. In view of the system dynamics, this study analyzes the positioning control errors for the control method in the wire-length coordinates. We discuss a case study on a two degrees-of-freedom planar system using three wires.

Aerial Contact Manipulation With Soft End-Effector Compliance and Inverse Kinematic Compensation

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xinjun Sheng ◽  
Zhao Ma ◽  
Ningbin Zhang ◽  
Wei Dong
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Mechanical Design ◽  
Impact Resistance ◽  
High Strength ◽  
Inverse Kinematic ◽  
End Effector ◽  
Precise Position ◽  
Positioning Errors ◽  
Aerial Platform

Abstract This paper presents the development of a six degrees-of-freedom manipulator with soft end-effector and an inverse kinematic compensator for aerial contact manipulation. Realizing the fact that aerial manipulators can hardly achieve precise position control, a compliant manipulator with soft end-effector is first developed to moderate end-effector positioning errors. The manipulator is designed to be rigid-soft combined. The rigid robotic arm employs the lightweight but high-strength materials. The compliance requirement is achieved by the soft end-effector so that the mechanical design for the joints are largely simplified. These two features are beneficial to lighten the arm and to ensure the accuracy. In the meantime, the pneumatic soft end-effector can further moderate the probable insufficient accuracy by endowing the manipulator with compliance for impact resistance and robustness to positioning errors. With the well-designed manipulator, an inverse kinematic compensator is then proposed to eliminate lumped disturbances from the aerial platform. The compensator can ensure the stabilization of the end-effector by using state estimation from the aerial platform, which is robust and portable as the movement of the platform can be reliably obtained. Both the accuracy and compliance have been well demonstrated after being integrated into a hexarotor platform, and a representative scenario aerial task repairing the wind turbine blade-coating was completed successfully, showing the potential to accomplish complex aerial manipulation tasks.

scholarly journals Analytical inverse kinematics for 5-DOF humanoid manipulator under arbitrarily specified unconstrained orientation of end-effector

Robotica ◽  
2014 ◽  
Vol 33 (4) ◽  
pp. 747-767 ◽  
Author(s):  
Masayuki Shimizu
Keyword(s):  
Analytical Method ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Singularity Analysis ◽  
Inverse Kinematic ◽  
Inverse Kinematic Problem ◽  
Target Orientation ◽  
End Effector ◽  
Position And Orientation

SUMMARYThis paper proposes an analytical method of solving the inverse kinematic problem for a humanoid manipulator with five degrees-of-freedom (DOF) under the condition that the target orientation of the manipulator's end-effector is not constrained around an axis fixed with respect to the environment. Since the number of the joints is less than six, the inverse kinematic problem cannot be solved for arbitrarily specified position and orientation of the end-effector. To cope with the problem, a generalized unconstrained orientation is introduced in this paper. In addition, this paper conducts the singularity analysis to identify all singular conditions.

Workspace Generation for a 2 - DOF Parallel Mechanism Using Neural Networks

2012 ◽  
Vol 162 ◽  
pp. 121-130 ◽  
Author(s):  
Emilia Campean ◽  
Tiberiu Pavel Itul ◽  
Ionela Tanase ◽  
Adrian Pisla
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Inverse Kinematic ◽  
Two Degrees Of Freedom ◽  
Initial Testing ◽  
Network Application ◽  
Satellite Dish

The main purpose of the paper is to develop a neural network application destined to the workspace generation of a parallel mechanism, as an performant alternative to the workspace representation based on inverse kinematic model. The paper describes both algorithms. The initial testing was made for a parallel mechanism with two degrees of freedom that could be applied for the orientation of different systems like a TV satellite dish antennas, sun trackers, telescopes, cameras, radars etc.

Visual Control of Robotic Manipulator Based on Artificial Neural Network

1991 ◽  
Vol 3 (5) ◽  
pp. 394-400 ◽  
Author(s):  
Hideki Hashimoto ◽  
◽  
Takashi Kubota ◽  
Motoo Sato ◽  
Fumio Harashima ◽  
...  
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Visual Information ◽  
Degrees Of Freedom ◽  
Robotic Manipulator ◽  
Inverse Kinematic ◽  
End Effector ◽  
Control Scheme ◽  
Neural Network System ◽  
Artificial Neural

This paper describes a control scheme for a robotic manipulator system which uses visual information to position and orientate the end-effector. In the scheme the position and the orientation of the target workpiece with respect to the base frame of the robot are assumed to be unknown, but the desired relative position and orientation of the end-effector to the target workpiece are given in advance. The control system directly integrates visual data into the servoing process without subdividing the process into determination of the position, orientation of the workpiece and inverse kinematic calculation. An artificial neural network system is used for determining the change in joint angles required in order to achieve the desired position and orientaion. The proposed system can control the robot so that it approach the desired position and orientaion from arbitary initial ones. Simulation for the robotic manipulator with six degrees of freedom is done. The validity and the effectiveness of the proposed control scheme are varified by computer simulations.

Kinematic model to control the end-effector of a continuum robot for multi-axis processing

Robotica ◽  
2015 ◽  
Vol 35 (1) ◽  
pp. 224-240 ◽  
Author(s):  
Salvador Cobos-Guzman ◽  
David Palmer ◽  
Dragos Axinte
Keyword(s):  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Euler Angle ◽  
Inverse Kinematic ◽  
End Effector ◽  
Six Degrees Of Freedom ◽  
Hazardous Environments ◽  
Continuum Robot ◽  
Novel Method ◽  
Six Dof

SUMMARYThis paper presents a novel kinematic approach for controlling the end-effector of a continuum robot for in-situ repair/inspection in restricted and hazardous environments. Forward and inverse kinematic (IK) models have been developed to control the last segment of the continuum robot for performing multi-axis processing tasks using the last six Degrees of Freedom (DoF). The forward kinematics (FK) is proposed using a combination of Euler angle representation and homogeneous matrices. Due to the redundancy of the system, different constraints are proposed to solve the IK for different cases; therefore, the IK model is solved for bending and direction angles between (−π/2 to +π/2) radians. In addition, a novel method to calculate the Jacobian matrix is proposed for this type of hyper-redundant kinematics. The error between the results calculated using the proposed Jacobian algorithm and using the partial derivative equations of the FK map (with respect to linear and angular velocity) is evaluated. The error between the two models is found to be insignificant, thus, the Jacobian is validated as a method of calculating the IK for six DoF.

Hybrid Force-Position Control Three Fingers End Effector

2013 ◽  
Vol 346 ◽  
pp. 75-82
Author(s):  
Vladimir Prada Jiménez ◽  
Oscar Fernando Avilés Sánchez ◽  
Mauricio M. Mauledoux
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Kinematics And Dynamics ◽  
End Effector ◽  
Matlab Simulink ◽  
Two Degrees Of Freedom ◽  
Hybrid Controller

This paper describes the implementation of a hybrid controller to an end effector of threefingers, each finger with two degrees of freedom (2 DOF). Since the mobility of each phalanx showsthe workspace by finger. Modeling is presented which includes the kinematics and dynamics offector and implementation of force-position hybrid controller. Simulations are presented to validatethe behavior of the finger and the controller in Matlab Simulink.

scholarly journals Sistem Pick and Place Dua Derajat Kebebasan menggunakan Metoda Regresi

2019 ◽  
Vol 7 (3) ◽  
pp. 521
Author(s):  
ERWANI MERRY SARTIKA ◽  
RUDI SARJONO ◽  
HAZEL XARIS CHRISOPHRAS
Keyword(s):  
Degrees Of Freedom ◽  
Industrial Robot ◽  
Regression Method ◽  
Robot Design ◽  
Servo Motor ◽  
End Effector ◽  
Two Degrees Of Freedom ◽  
Pick And Place ◽  
The Relationship

ABSTRAKSistem pick and place merupakan suatu sistem mekanik yang digunakan untuk memanipulasi pergerakan mengangkat, memindahkan, dan meletakkan untuk meringankan kerja manusia. Dalam mempelajari cara kerja robot industri sederhana dibuat miniatur robot pick and place (sederhana). Perancangan yang dibuat yaitu sistem pick and place dengan dua derajat kebebasan dengan ukuran yang memiliki perbandingan 1:0.35 dari referensi ukuran desain robot. Aplikasi SolidWorks digunakan untuk mendesain robot Diamond. Metode Regresi digunakan untuk memprediksi posisi motor servo dalam mencapai posisi yang diinginkan. Metode regresi berhasil digunakan untuk mencari hubungan antara target posisi setpoint dengan posisi motor servo 1 dan 2 (persamaan orde 2 dan 3) untuk mengontrol motor servo. Performansi yang terbaik dari sistem pick and place yang dibuat menggunakan trayektori miring, dengan kecepatan 100 (11.1 rpm), menghasilkan error ± 0.0729 dan presisi 1.63%. Dalam penelitian ini, kecepatan end-effector yang lebih rendah menghasilkan keakurasian dan kepresisian yang lebih baik.Kata kunci: Pick and Place, Robot Diamond, Dua derajat kebebasan, Regresi ABSTRACTThe pick and place system are a mechanic system used in manipulating the movements of lifting, moving, and laying to ease human work. In learning how to work a simple industrial robot, a miniature pick and place robot is created. The design made is a pick and place system with two degrees of freedom with a size that has a ratio of 1: 0.35 from the reference size of the robot design. Regression method is used to predict the position of the servo motor in reaching the desired position. Regression method was successfully used to find the relationship between the target setpoint position and the position of servo motors 1 and 2 (order equations 2 and 3) to control the servo motor. The best performance from the pick and place system that is made using an aslope trajectory, with a speed of 100 (11.1 rpm), produces an error ± 0.0729 and precision 1.63%. In this research, lower end-effector speeds result in better accuracy and precision.Keywords: Pick and Place, Diamond Robot, 2-DOF, Regression

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