Difference between revisions of "Assigning coordinate frames"

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The coordinate frames are always attached to the end of the links at the distal joints. The first coordinate frame, indexed <math>K_0</math>, is the base or reference frame and attached to the base in joint <math>J_1</math>. The next frame is <math>K_1</math> at the end of link <math>L_1</math> in joint <math>J_2</math> followed by <math>K_2</math> at the end of <math>L_2</math> and so on. The coordinate frame <math>K_n</math> of the last link is finally attached to the end of of the manipulator and so to the end-effector.
 
The coordinate frames are always attached to the end of the links at the distal joints. The first coordinate frame, indexed <math>K_0</math>, is the base or reference frame and attached to the base in joint <math>J_1</math>. The next frame is <math>K_1</math> at the end of link <math>L_1</math> in joint <math>J_2</math> followed by <math>K_2</math> at the end of <math>L_2</math> and so on. The coordinate frame <math>K_n</math> of the last link is finally attached to the end of of the manipulator and so to the end-effector.
  
[[File:links.png|left|850px]]  
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[[File:links.png|left|850px]]
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===Main joint axes===
 
===Main joint axes===
  

Revision as of 16:37, 30 October 2015

← Back: Denavit-Hartenberg Convention Overview: Denavit-Hartenberg Convention Next: Denavit-Hartenberg parameters

To be able to determine the spatial relationship or transformation, respectively, between the links of a manipulator, local coordinate frames have to assigned to them first. There are several rules that have to be observed when assigning coordinate frames following the Denavit-Hartenberg convention.

Notation

The notation of the links and joints is shown in the figure below. A manipulator consists of n links that are connected with n joints. The links correspond to the rigid parts of an arm and the joints are the flexible connections between them. A joint is always assigned to the proximate link. So a link L_i is connected with its joint J_i to the end of link L_{i-1}. The proximate link L_{i+1} is then mounted to the end of L_i via its joint J_{i+1}. The first link L_1 is mounted on the base via joint J_1. So the base is actually link L_0 that does not directly belong to the manipulator. The end of the last link L_n corresponds to the end-effector.

The coordinate frames are always attached to the end of the links at the distal joints. The first coordinate frame, indexed K_0, is the base or reference frame and attached to the base in joint J_1. The next frame is K_1 at the end of link L_1 in joint J_2 followed by K_2 at the end of L_2 and so on. The coordinate frame K_n of the last link is finally attached to the end of of the manipulator and so to the end-effector.

Links.png

Main joint axes

Hier kommt text

Privres-zaxes.png