Difference between revisions of "Denavit-Hartenberg parameters"
From Robotics
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[[File:dh-params-general.png|right|250px]] | [[File:dh-params-general.png|right|250px]] | ||
| − | When the [[Assigning coordinate frames|coordinate frames]] are assigned to a manipulator, the transformation between each two consecutive frames <math>K_{n-1}</math> and <math>K_n</math> | + | When the [[Assigning coordinate frames|coordinate frames]] are assigned to a manipulator, the transformation between each two consecutive frames has to be described. Therefor the 4 Denavit-Hartenberg parameters <math>\theta</math>, <math>d</math>, <math>l</math> and <math>\alpha</math> are used. The figure on the right shows two coordinate frames <math>K_{n-1}</math> and <math>K_n</math> and illustrates the parameters. The corresponding [[Common normal|common normal]] is represented by a dashed red line. The Denavit-Hartenberg parameters are defined as follows: |
;<math>\theta</math> | ;<math>\theta</math> | ||
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;<math>d</math> | ;<math>d</math> | ||
| − | :<math>d</math> is the offset or translation, respectively, along the <math>z_{n-1}</math>-axis from the origin of <math>K_{n-1}</math> to the intersection with the [[Common normal|common normal]] | + | :<math>d</math> is the offset or translation, respectively, along the <math>z_{n-1}</math>-axis from the origin of <math>K_{n-1}</math> to the intersection with the [[Common normal|common normal]]. |
;<math>l</math> | ;<math>l</math> | ||
Revision as of 18:16, 12 November 2015
| ← Back: Assigning coordinate frames | Overview: Denavit-Hartenberg Convention | Next: A-matrices → |
When the coordinate frames are assigned to a manipulator, the transformation between each two consecutive frames has to be described. Therefor the 4 Denavit-Hartenberg parameters 
, 
, 
and 
are used. The figure on the right shows two coordinate frames 
and 
and illustrates the parameters. The corresponding common normal is represented by a dashed red line. The Denavit-Hartenberg parameters are defined as follows:
- The angle is defined as the angle about the
-axis to align 
with the new 
-axis.
- is the offset or translation, respectively, along the -axis from the origin of to the intersection with the common normal.
- The parameter corresponds to the length of the common normal which is equivalent to the translation along it.
- If the related joint
is a revolute joint, can also be regarded as the radius of the rotation about the -axis
- The angle corresponds to the angle about the common normal to align the -axis with the new
-axis
