Robots always in collision state

[eme...@cc.ci.ufpb.br]

Hello. I'm working with the Motoman SDA5D, using the Gazebo 6 and ROS Indigo, onUbuntu 14.04. As I don't have the MoveIt! configuration files for this robot (because I've construted the URDF description from the original CAD files), I had to configure with the setup assistant.

The self-collision matrix generation and planning groups configuration are ok, but in Robot Poses tab, an alert is shown: "Robot in collision state". It shows even if I don't move the joints and keep the arm straight:

- http://i.imgur.com/UhbMufv.png

- http://i.imgur.com/fymg6V0.png (the robot with RobotiQ grippers; doesn't make a big difference)

If I ignore this part and generate the moveit_config package, when I launch the demo.launch to test the robot with MoveIt!, it fails to find a trajectory, because of this problem, "Robot in collision state".

For curiosity, I've made the same thing to an arm that I was working with, the Kinova MICO. Before, the setup assistant was cool with it, but now it complains, with the same error message:

- http://i.imgur.com/PLllBPq.png

I don't know if it is a problem in the robot files, or it is a MoveIt! bug. Any help would be welcome.

Best regards,

Emerson

[Simon Schmeißer]

sometimes you have to tweak the allowed collision matrix in the srdf file, have a look at the collision model view (Show robot collision) in rviz and see if any joints are intersecting. If they can't actually ever collide (joint limits etc), add them to the allowed collision list.

You could also use setup assistant, there is a checkbox or something on the allowed collision page to show all possible collisions. Maybe you can disable a few more collisions and see if the error disappears. Just be careful when you connect to real hardware

[eme...@cc.ci.ufpb.br]

Hello Simon. Thanks for your answer.
With JACO, I forgot to run the collision detection. So I runned again, now with collision detection and now it's fine. My bad.
However, with Motoman, I saw that there's a bug in RobotiQ gripper xacro file that is causing the "robot in collision state" warning, independently if I run the collision detection or mark all the links as "never collide".
I'm using the DRCSim version of RobotiQ gripper description. I'll do a reverse engineering on the xacro file to know what is causing this.

Thanks once again

[Qiang Qiu]

Hi, Emerson

I have some problem with the figure you show (http://i.imgur.com/UhbMufv.png).

I think it is the URDF for SDA10, rather than SDA5. I'm not really sure, but the default configuration of E joint isn't right. (https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcRugvIK-wGwi8lGMfS9kMZgt-2rJV_kYfGGRaeh-o3sQMJ8MS3o8w)

I'm working with SDA5F, and here is my URDF files (https://github.com/qqfly/motoman/tree/indigo-devel/motoman_sda5f_support).

[Emerson Ferreira]

Hi Qiang.

I changed the URDF files to the Motoman SDA5D model.

I was using the Motoman SDA10 for tests purposes only.

[Max Gittelman]

I had the same problem, and simply forget to "Generate Collision Matrix" in the "Self-Collisions" tab of the MoveIt Setup Assistant. Thanks for the help all of you. Your efforts haven't gone unnoticed!