I need to convert kinematic parameters written in "modified Denavit-Hartenberg's notation" (like as explained by Craig) into kinematic parameters in "standard Denavit-Hartenberg's notation" (like as explained by Asada-Slotine).
Can u tell me where i can find a link or a book that explain this conversion? Thanks.
This paper gives a fair descrioption of the geometry used in the Craig modified DH notation
Ignoring indices, Asada-Slotine's (Paul's) Denavit-Hartenberg notation uses the following rigid-body-transformation sequence for each link:
[z-rotation (by theta), z-translation (by d), x-rotation (by alpha), x-translation (by a)]Craig's notation uses the following:
[x-rotation, x-translation, z-rotation, z-translation](The order of rotation and translation along the same axis can be exchanged wherever it appears in both forms.)
So, converting from Craig's notation to Asada-Slotine is doable in most cases by concatinating the sequences for all the links and regrouping. For example, assuming a two-link manipulator for brevity,
[0-rotation,0-translation, z-rotation1,z-translation1][x-rotation2,x-translation2,z-rotation2,z-transla tion2] (Craig)becomes
[z-rotation1, z-translation1, x-rotation2, x-translation2] [z-rotation2, z-translation2, 0-rotation, 0-translation] (Asada-Slotine)The indices used here (1 and 2) are just placeholders. It is hopefully easy to see how this would extend to manipulators with more than two links. Direct conversion only works when the Craig form has zero x translation and rotation for the first link. When this is not the case, the manipulator's reference frame will need to change.
The conversion will always produde an Asada-Slotine form with zero x rotation and translation for the last link.
James English Energid Technologies
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