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Inverse kinematics for 5dof arm

asked 2018-11-06 11:37:44 -0500

mwrighte38 gravatar image

I've removed a joint from a 6dof arm and am trying to use it as a 5dof arm.

When using moveit I've learned that I need to have allow approximate solutions checked however there isn't a way to set this programatically for cartesian coordinate solutions with the moveit api. I'm only able to set joints to approximate solutions individually.

The joint removed was only a only a rotation joint because I have I guess what would end up being a katana style arm and do not care about the rotation of the end effector relative to the object it is approaching.

After learning I couldn't use the default planner I tried using the IKfast plugin to generate a Solver for a 5dof arm. I created the files needed to create an IKfast solver per documentation however this failed. Even when I tried using a few other solutions found on other posts such as

Is there some qucik-ish way for me to I guess trick the solver into believing it can still execute the trajectory even though there isn't this 6th rotation joint?

Let me know if I need to provide any files to help explain.

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Could you not set it up so the solver was working with the 6dof arm but the final joint is ignored by a ready 5dof arm. This means the solver will always find a solution but the robot will not actuate the final irrelevant angle.

PeteBlackerThe3rd gravatar image PeteBlackerThe3rd  ( 2018-11-06 12:33:49 -0500 )edit

This is what I was thinking about doing but I keep getting errors saying unable to find the required joints and haven't had time to look through the software yet to make some edits. Most likely it is what I will end up doing but I was looking for any other suggestions as well.

mwrighte38 gravatar image mwrighte38  ( 2018-11-06 12:54:34 -0500 )edit

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answered 2018-11-08 11:53:01 -0500

mwrighte38 gravatar image

The solution that I came up for this was actually to ignore angles because they currently do not matter for my project.

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Asked: 2018-11-06 11:37:44 -0500

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Last updated: Nov 08 '18