Optimal Geometric Design of Robot Manipulator Link Shapes

1995 ◽  
Author(s):  
Q. Tu ◽  
J. Rastegar
Keyword(s):  
Present Method ◽  
Recent Article ◽  
Robot Manipulator ◽  
Geometric Design ◽  
Task Space ◽  
Operational Environment ◽  
End Effector ◽  
Numerical Examples ◽  
The Monte Carlo Method ◽  
Manipulator Link

Abstract In a recent article, Rastegar and Tu (1993), the authors presented a method for determining allowable link shapes for robot manipulators once their preferred operational environment is specified. The operational environment may include the preferred size and geometry of the end-effector task space(s), the obstacle and the installation spaces, and the enclosure within which the robot is to operate. In this method, by defining weighted (preferred) distributions for the task and/or obstacle spaces and for the enclosure geometry, weighted allowable manipulator link shapes are determined. In the present study, the developed method is extended to address the problem of optimal geometric design of robot manipulator link shapes. The developed methods are very simple, numeric in nature, readily implemented on computer, and can be classified as being based on the Monte Carlo method. The extension of the present method to the solution of optimal geometric shape synthesis for task and obstacle spaces is discussed. Numerical examples are presented.

Determination of the Allowable Manipulator Link Shapes; and Task, Installation, and Obstacle Spaces Using the Monte Carlo Method

1989 ◽  
Author(s):  
J. Rastegar ◽  
Q. Tu
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Shape Design ◽  
Task Space ◽  
Operating Environment ◽  
End Effector ◽  
The Monte Carlo Method ◽  
Manipulator Link ◽  
And Task

Abstract The Monte Carlo method is used to solve a number of problems in manipulator link shape design, and in task space and obstacle placement. The shape of links of manipulators that are to operate within geometrically specified enclosures are determined. Within the enclosure, one or several obstacles may be present. The end effector operates within the task space, and may be required to reach points in different regions with different orientations. For a specified operating environment (enclosure geometry and obstacles), the spaces within which a given manipulator may be installed in order to perform the required tasks are identified. For a given enclosure, task space, and position of the fixed joint of the manipulator, regions within which obstacles may be placed are mapped. The developed methods are very simple, numeric in nature, and readily implemented on computer. Several examples are presented.

Determination of Allowable Manipulator Link Shapes; and Task, Installation, and Obstacle Spaces Using the Monte Carlo Method

1993 ◽  
Vol 115 (3) ◽  
pp. 457-461 ◽  
Author(s):  
Q. Tu ◽  
J. Rastegar
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Shape Design ◽  
Task Space ◽  
Operating Environment ◽  
Design Task ◽  
The Monte Carlo Method ◽  
Manipulator Link ◽  
And Task

The Monte Carlo method is used to solve a number of manipulator link shape design, task space, and obstacle placement problems. The shape of links of manipulators that are to operate within geometrically specified enclosures are determined. Within the enclosure, one or several obstacles may be present. For a specified operating environment, the spaces within which a given manipulator may be installed in order to perform the required tasks are identified. For a given enclosure, the allowable task spaces, and regions within which obstacles may be placed are mapped. By defining weighted distributions for the task and/or obstacle spaces, weighted allowable link shapes, and task and obstacle spaces are determined. The information can be used for optimal link shape synthesis, and for optimal task, obstacle, and manipulator placement purposes. The developed methods are very simple, numeric in nature, and readily implemented on computer. Several examples are presented.

Cooperation and Null-Space Control of Networked Omni-Directional Mobile Manipulators

2020 ◽  
Author(s):  
Michael John Chua ◽  
Yen-Chen Liu
Keyword(s):  
Degrees Of Freedom ◽  
Null Space ◽  
Kinematic Model ◽  
Mobile Manipulator ◽  
Main Task ◽  
Mobile Manipulators ◽  
Robot Arm ◽  
Task Space ◽  
End Effector ◽  
Mobile Base

Abstract This paper presents cooperation and null-space control for networked mobile manipulators with high degrees of freedom (DOFs). First, kinematic model and Euler-Lagrange dynamic model of the mobile manipulator, which has an articulated robot arm mounted on a mobile base with omni-directional wheels, have been presented. Then, the dynamic decoupling has been considered so that the task-space and the null-space can be controlled separately to accomplish different missions. The motion of the end-effector is controlled in the task-space, and the force control is implemented to make sure the cooperation of the mobile manipulators, as well as the transportation tasks. Also, the null-space control for the manipulator has been combined into the decoupling control. For the mobile base, it is controlled in the null-space to track the velocity of the end-effector, avoid other agents, avoid the obstacles, and move in a defined range based on the length of the manipulator without affecting the main task. Numerical simulations have been addressed to demonstrate the proposed methods.

scholarly journals A Novel Kinematically Redundant Planar Parallel Robot Manipulator With Full Rotatability

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Nicholas Baron ◽  
Andrew Philippides ◽  
Nicolas Rojas
Keyword(s):  
Potential Application ◽  
Robot Manipulator ◽  
Video Recording ◽  
Parallel Robot ◽  
Singularity Analysis ◽  
Geometric Method ◽  
Forward Kinematics ◽  
Online Video ◽  
End Effector ◽  
Moving Platform

This paper presents a novel kinematically redundant planar parallel robot manipulator, which has full rotatability. The proposed robot manipulator has an architecture that corresponds to a fundamental truss, meaning that it does not contain internal rigid structures when the actuators are locked. This also implies that its rigidity is not inherited from more general architectures or resulting from the combination of other fundamental structures. The introduced topology is a departure from the standard 3-RPR (or 3-RRR) mechanism on which most kinematically redundant planar parallel robot manipulators are based. The robot manipulator consists of a moving platform that is connected to the base via two RRR legs and connected to a ternary link, which is joined to the base by a passive revolute joint, via two other RRR legs. The resulting robot mechanism is kinematically redundant, being able to avoid the production of singularities and having unlimited rotational capability. The inverse and forward kinematics analyses of this novel robot manipulator are derived using distance-based techniques, and the singularity analysis is performed using a geometric method based on the properties of instantaneous centers of rotation. An example robot mechanism is analyzed numerically and physically tested; and a test trajectory where the end effector completes a full cycle rotation is reported. A link to an online video recording of such a capability, along with the avoidance of singularities and a potential application, is also provided.

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.

Kontrol Lengan Robot Badminton dan Analisis Kinematika

2020 ◽  
Vol 2 (2) ◽  
pp. 72
Author(s):  
Handika Dwi Cahyono ◽  
Indrazno Siradjuddin ◽  
Budhy Setiawan
Keyword(s):  
Robot Manipulator ◽  
Tuning Parameter ◽  
End Effector ◽  
Set Point ◽  
Proportional Integral

Lengan robot manipulator adalah suatu sistem mekanik yang digunakan dalam memanipulasi pergerakan mengangkat, memindahkan, dan memanipulasi benda kerja untuk meringankan kerja manusia. Lengan robot dalam penelitian ini memanipulasi gerakan memukul shuttlecock seperti pada permainan badminton. Model kinematika merepresentasikan hubungan end effector dalam ruang tiga dimensi dengan variabel sendi dalam ruang sendi. Metode Denavit-Harternberg merupakan sebuah metode yang digunakan untuk membentuk persamaan kinematik yang menggunakan 4 parameter yaitu θ, α, d dan a. Hasil dari penelitian ini didapat persamaan kinematik maju dan kinematik balik yang dapat digunakan sebagai acuan dalam memprogram gerakan lengan robot ke dalam sistem control.Agar Gerakan lengan robot stabil, maka dibutuhkan kontroller PID (Proportional, Integral, dan Differensial) untuk mengontrol kecepatan motor pada lengan robot. Pada penelitian ini mengimplementasikan metode Ziegler-Nichols untuk mendapatkan parameter  PID (KP, KI dan KD). Hasil pengujian tuning parameter PID menggunakan metode Ziegler-Nichols didapatkan nilai KP=0,92, KI=4,11 dan KD=0,03. Dengan menggunakan parameter tersebut kecepatan motor menjadi lebih stabil mendekati set point.

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.

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