An Approach of Robotic Kinematics Parameters Calibration

2013 ◽  
Vol 655-657 ◽  
pp. 1023-1028 ◽  
Author(s):  
Yong Gui Zhang ◽  
Heng Zhang
Keyword(s):  
Laser Interferometer ◽  
Joint Angle ◽  
Hybrid Genetic Algorithm ◽  
Robot Kinematics ◽  
Robot Calibration ◽  
End Effector ◽  
Position Data ◽  
Recorded Data ◽  
Kinematics Parameters ◽  
System Axis

Aiming at tedious of parameters identification in the process of robot calibration, this paper proposed a method to directly establish parameter error equations based on relative distance error by using the kinematics model in which the parameters error were considered, employing a laser interferometer to measure a 6R robot end-effector displacement distance along its Cartesian coordinates system axis direction, and respectively recorded the joint angle position data to the measured points, then taking all recorded data as basis for the robot kinematics parameter errors identifying equations and employing a hybrid genetic algorithm to solve the equations. The result shown that incomplete distance info can be used to identify kinematics parameters error in robot calibration process.

Pose Accuracy Analysis of Robot Manipulators Based on Kinematics

2011 ◽  
Vol 201-203 ◽  
pp. 1867-1872 ◽  
Author(s):  
Jian Ye Zhang ◽  
Chen Zhao ◽  
Da Wei Zhang
Keyword(s):  
Matrix Theory ◽  
Robot Manipulators ◽  
Error Model ◽  
Robot Kinematics ◽  
Accuracy Analysis ◽  
Serial Link ◽  
End Effector ◽  
Surface Graph ◽  
Position And Orientation ◽  
Kinematics Parameters

The pose accuracy of robot manipulators has long become a major issue to be considered in its advanced application. An efficient methodology to generate the end-effector position and orientation error model of robotic manipulator has been proposed based on the differential transformation matrix theory. According to this methodology, a linear error model that described the end-effector position and orientation errors due to robot kinematics parameters errors has been presented. A computer program to generate the error model and perform the accuracy analysis on any serial link manipulator has been developed in MATLAB. This methodology and software are applied to the accuracy analysis of a Phantom Desktop manipulator. The positioning error of the manipulator in its workspace cross section (XOZ) has been plotted as 3D surface graph and discussed.

scholarly journals Controlling of a ROS-based robotic system in accordance to the assist-as-needed principle in end-effector based rehabilitation systems

2018 ◽  
Vol 4 (1) ◽  
pp. 199-202
Author(s):  
Sebastian Becker ◽  
Wiebke Hinterlang ◽  
Tim Eschert ◽  
Catherine Disselhorst-Klug
Keyword(s):  
Impedance Control ◽  
Proximal Part ◽  
The Elderly ◽  
Subjective Assessment ◽  
Robot Kinematics ◽  
Robotic Rehabilitation ◽  
End Effector ◽  
3 Dimensional ◽  
The Central Nervous System ◽  
Robotic Devices

AbstractStroke is one of the most frequent diseases among the elderly and often leads to an ongoing failure of functions in the central nervous system. Due to the plasticity of the brain affected may regain lost motor function by repetitive training. Robotic devices can be an approach to accelerate the rehabilitation process by maximizing patients’ training intensity. End-effector based robotic systems are particularly suitable for this purpose and often an advantage over exoskeletons since the proximal part of the upper limb remains under the control of the patient. Furthermore, the integration of the assistas- needed principle (AAN) into these devices enables individualized, adaptable robotic support to patients during therapy. In this study an end-effector based robotic rehabilitation device based on the Robot Operating System (ROS) framework is introduced. The system allows patients to perform 3- dimensional movements without a therapist’s assistance. With regard to the AAN, focus was based on impedance control and an additional real-time adaption of the impedance control parameters by using a feedback loop. 10 healthy subjects took part in this study to evaluate the overall concept with regard to usability and quality of the supported movement. Hence, the three most promising adaption models of AAN (without adaption, adaption according to position and time, adaption according to velocity) under three different levels of movement support (0%, 50%, 100%) were investigated by administering a self-designed questionnaire and the robot kinematics. The results showed no significant differences between the three different adaption models of AAN. However, the subjective assessment of the movements was in keeping with robot kinematics and the control approaches as well as the overall system have experienced remarkable support.

scholarly journals A New Approach to the Solution of Robot Kinematics Based on Relative Transformation Matrices

2016 ◽  
Vol 5 (3) ◽  
pp. 213
Author(s):  
Mohammad Reza Elhami ◽  
Iman Dashti
Keyword(s):  
Robot Manipulator ◽  
Robot Kinematics ◽  
Coordinate Frame ◽  
End Effector ◽  
New Approach ◽  
Transformation Matrices ◽  
The World ◽  
Convenient Approach ◽  
Position And Orientation ◽  
Relative Transformation

In analyzing robot manipulator kinematics, we need to describe relative movement of adjacent linkages or joints in order to obtain the pose of end effector (both position and orientation) in reference coordinate frame. Denavit-Hartenberg established a method based on a 4×4 homogenous matrix so called “A” matrix. This method used by most of the authors for kinematics and dynamic analysis of the robot manipulators. Although it has many advantages, however, finding the elements of this matrix and link/joint’s parameters is sometimes complicated and confusing. By considering these difficulties, the authors proposed a new approach called ‘convenient approach’ that is developed based on “Relative Transformations Principle”. It provides a very simple and convenient way for the solution of robot kinematics compared to the conventional D-H representation. In order to clarify this point, the kinematics of the world known Stanford manipulator has been solved through D-H representation as well as convenient approach and the results are compared.

scholarly journals A novel solution of inverse kinematic for 6R robot manipulator with offset joint based on screw theory

2020 ◽  
Vol 17 (3) ◽  
pp. 172988142092564
Author(s):  
Zhiwei Liao ◽  
Gedong Jiang ◽  
Fei Zhao ◽  
Xuesong Mei ◽  
Yang Yue
Keyword(s):  
Joint Angle ◽  
Screw Theory ◽  
Robot Manipulator ◽  
Inverse Kinematic ◽  
Transformation Matrix ◽  
Inverse Kinematic Problem ◽  
End Effector ◽  
Closed Form Solutions ◽  
Specific Configuration ◽  
Kinematic Approach

This article proposes a novel inverse kinematic approach with translation transformation matrix based on screw theory to solve the inverse kinematic problem for 6R robot manipulator with offset joint. The translation transformation matrix is introduced to convert the 6R robot manipulator with offset joint to a new configuration with intersecting axes, and the mapping relationship from the end effector to the joint angle is established along with the Paden–Kahan subproblems. The eight closed solutions of the specific configuration are deduced, which automatically eliminate the singularity solutions. Moreover, the precision and efficiency of the proposed method are verified through a numerical example. Unlike other approaches, the presented algorithm not only inherits the superior accuracy of the other geometric approaches but also exhibits an outperform efficiency. Finally, the method is generalized to other 6R robots, which has closed-form solutions to further verify its versatility. The presented study provides some basis for further investigations, such as trajectory planning and motion control, which provides a new tool on the analysis and application of this kind of robot manipulator.

scholarly journals Adjustments in end-effector trajectory and underlying joint angle synergies after a target switch: Order of adjustment is flexible

PLoS ONE ◽  
2020 ◽  
Vol 15 (9) ◽  
pp. e0238561
Author(s):  
Maureen B. G. Wissing ◽  
Laura Golenia ◽  
Joanne Smith ◽  
Raoul M. Bongers
Keyword(s):  
Joint Angle ◽  
End Effector

Improvement of the Accuracy of a PUMA 560 Industrial Manipulator by Calibration

1996 ◽  
Vol 210 (1) ◽  
pp. 55-67
Author(s):  
A R Greig ◽  
S P Lovell
Keyword(s):  
Supervisory Control ◽  
Joint Angle ◽  
Correction Function ◽  
Positional Accuracy ◽  
End Effector ◽  
Industrial Manipulator ◽  
Angle Measurements ◽  
Point Analysis ◽  
Industrial Manipulators ◽  
Data Points

Compared to their repeatability, the accuracy of industrial manipulators is disappointingly poor. To permit off-line programming of manipulators and interaction with their local surrounds a high positional accuracy is required; this is particularly true for operation under supervisory control. The accuracy of a manipulator can be improved by calibration of its link lengths and joint angle measurements. This paper presents the results of the calibration of a PUMA 560 industrial manipulator and discusses simplifications to the procedure and theory which improve the practicality of the method without seriously compromising the results. Circle point analysis is used with data points being recorded by a pair of theodolites; the relevant theory is presented in the Appendix. A joint error correction function is produced for each joint. A fourfold improvement in accuracy is demonstrated without unduly increasing the complexity of the kinematics or requiring a sophisticated end effector.

Joint angle variations analyses of the two link planar manipulator in welding by using inverse kinematics

Robotica ◽  
2005 ◽  
Vol 24 (3) ◽  
pp. 355-363 ◽  
Author(s):  
S. Bulut ◽  
M. B. Terzioǧlu
Keyword(s):  
Angular Velocity ◽  
Data Collection ◽  
Inverse Kinematics ◽  
Joint Angle ◽  
Joint Angles ◽  
End Effector ◽  
Fortran 90

In this paper, the joint angles of a two link planar manipulator are calculated by using inverse kinematics equations together with some geometric equalities. For a given position of the end-effector the joint angle and angular velocity of the links are derived. The analyses contains many equations which have to be solved. However, the solutions are rather cumbersome and complicated, therefore a program is written in Fortran 90 in order to do, the whole calculation and data collection. The results are given at the end of this paper.

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