Difference between revisions of "Denavit-Hartenberg Convention"

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In the robotics field, one important aspect is the control of serial link manipulators or robotic arms, respectively. A serial link manipulator is a series of links connected with actuated joints, commonly with an end-effector attached to the last link. One of the most famous robotic arms is the Unimate Puma560, that is shown in the figure on the right.  
 
In the robotics field, one important aspect is the control of serial link manipulators or robotic arms, respectively. A serial link manipulator is a series of links connected with actuated joints, commonly with an end-effector attached to the last link. One of the most famous robotic arms is the Unimate Puma560, that is shown in the figure on the right.  
  
[[File:privres-raw.png|left|150px]]
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The spacial relationship between the links of a manipulator depends on the current joint parameters and so does the transformation of the end-effector with respect to the manipulators base frame. As for example objects are to be grabbed at certain positions and [[Kinematics|kinematics]] are highly dependent on it, the transformation of the end-effector is of high importance for the control of a robotic arm.
Each manipulator has a certain amount of joints, that can be controlled. There are two types of joints used for robotic arms, each with one single degree of freedom. In the following the abstractions shown in the figure on the left will be used. The first type is the prismatic joint, that allows for translational movement along the joint axis. The displacement is described by the joint variable, for example <math>d</math> like in the figure. The second joint type is the revolute joint. A revolute joint allows for a rotation about the joint or rotation axis, respectively, and its joint parameter is the rotation angle, named <math>\theta</math> in the figure. The Puma560 for example has three revolute joints (see figure on the right).
 
 
 
The spacial relationship between the links of a manipulator depends on the current joint parameters and so does the transformation of the end-effector with respect to the manipulators base frame. Depending on the angles of the three joints <math>J_1</math>, <math>J_2</math> and <math>J_3</math>, the end-effector of the Puma560, which is the black part at the end of the arm, is located at different positions and with a different orientation. As for example objects are to be grabbed at certain positions and [[Kinematics|kinematics]] are highly dependent on it, the transformation of the end-effector is of high importance for the control of a robotic arm.
 
  
 
The Denavit-Hartenberg convention covers methods to assign coordinate frames to the links of serial link manipulators and to describe the spatial relationship between them by four parameters. Using these methods, the transformation of the end-effector with respect to the manipulators base frame can easily be determined and used for further computations.  
 
The Denavit-Hartenberg convention covers methods to assign coordinate frames to the links of serial link manipulators and to describe the spatial relationship between them by four parameters. Using these methods, the transformation of the end-effector with respect to the manipulators base frame can easily be determined and used for further computations.  
  
 
In the following subarticles the individual aspects of the Denavit-Hartenberg convention are treated in detail:
 
In the following subarticles the individual aspects of the Denavit-Hartenberg convention are treated in detail:
*[[Assigning coordinate frames]]
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*[[Types of joints]]
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*[[Notation of links, joints and coordinate frames]]
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*[[Common normal]]
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*[[Assigning the coordinate frames]]
 
*[[Denavit-Hartenberg parameters]]
 
*[[Denavit-Hartenberg parameters]]
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*[[A-matrices]]
 
*[[Typical link examples]]
 
*[[Typical link examples]]
*[[A-matrices]]
 
  
 
[[Category:Article]]
 
[[Category:Article]]
 
[[Category:Denavit-Hartenberg]]
 
[[Category:Denavit-Hartenberg]]

Revision as of 15:52, 10 November 2015

← Back: Realization of transformations Overview: Denavit-Hartenberg Convention Next: Assigning coordinate frames
P560.png

In the robotics field, one important aspect is the control of serial link manipulators or robotic arms, respectively. A serial link manipulator is a series of links connected with actuated joints, commonly with an end-effector attached to the last link. One of the most famous robotic arms is the Unimate Puma560, that is shown in the figure on the right.

The spacial relationship between the links of a manipulator depends on the current joint parameters and so does the transformation of the end-effector with respect to the manipulators base frame. As for example objects are to be grabbed at certain positions and kinematics are highly dependent on it, the transformation of the end-effector is of high importance for the control of a robotic arm.

The Denavit-Hartenberg convention covers methods to assign coordinate frames to the links of serial link manipulators and to describe the spatial relationship between them by four parameters. Using these methods, the transformation of the end-effector with respect to the manipulators base frame can easily be determined and used for further computations.

In the following subarticles the individual aspects of the Denavit-Hartenberg convention are treated in detail: