Stewart Platform: how can i connect multiple joints to the same child link

Hi,

I think my problem is similar to this post already posted in 2015 here is the link

I want to simulate a robot in Gazebo. This robot contains a kind of delta machine. It consists in :

• three cylinders,

• three conrods, linked with the pistons rods (tigeverin) on one side and with one plate (platecamera_support) on the other side,

• a plate (platecamerasupport). My objective is to control the altitude and the orientation of the plate (platecamerasupport) around the X axis and Y axis.

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Here is the tf_tree of my URDF model. But unfortunately, I’m not able to introduce the last 2 joints of the model (in red on the picture below). Is the last answer still relevant? Is there a trick to face this « problem » ?

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PS: I’m working on Ubuntu 16.04 LTS and ROS Kinetic. Thanks in Advance

Asked by Abdel on 2019-01-24 15:35:52 UTC

Comments

Non-gazebo solution https://answers.ros.org/question/244903/how-to-simulate-a-stewart-platform-with-ros/

Asked by lucasw on 2019-01-24 19:23:17 UTC

Answers

Unless this is a Gazebo question (in which case it should have been posted on answers.gazebosim.org and SDF can be used) the situation described in #q244903 and #q216101 hasn't changed. That means it's not possible to model such a platform in URDF (or at least: you cannot model the multiple-parent constraint).

The answer posted by @lucasw in #q244903 would seem to be a nice work-around.

Asked by gvdhoorn on 2019-01-25 03:54:41 UTC