Gripper parts not shown as connected in Gazebo

[aamirhatim]

I'm not doing anything fancy, just running the default launch file from kortex_gazebo. Here's my command:
$ roslaunch kortex_gazebo spawn_kortex_robot.launch gripper:=robotiq_2f_85
(See output.txt for what gets printed to the terminal while everything starts up)

Everything starts as expected, but once the homing node unpauses Gazebo and the arm starts homing itself, the gripper parts start to disconnect and move away from the robot. Everything looks just fine in Rviz though.

I'm assuming I'm doing something wrong in Gazebo or I'm missing some kind of package/plugin, but has this happened to anyone else? I've installed all package dependencies as well. I tried this on the 2f 140 and got the same behavior. This only happens when a gripper is attached - the arm itself seems fine. Apologies if this type of question should be posted elsewhere.

ROS Melodic
Ubuntu 18.04

UPDATE: I did see the disclaimer in the readme about the arm stability but it looked like it was referring to the entire arm. The issue I'm having also doesn't happen "very rarely", it's every time I start the simulation and it persists after resetting the world in Gazebo. Not sure if this is the same issue or something else.

[phuicy]

I am also having this issue.

[phuicy]

I have tried debugging the mimic plugin, and tuning the parameters, but to no luck.
I think there might be some self-collisions. Essentially, the left_inner_finger floats and the first time it collides with an object the system become chaotic.

[alexvannobel]

Hi @aamirhatim and @phuicy ,

It seems this issue slipped as it aired when we had less staff working because of COVID-19 measures. Really sorry about the delay.

The problem was indeed linked to the mimic joint plugin and I had to add the ` tag to stop the gripper pieces from flying around.

The PR is #98 , I'll let you know and close the issue when it's merged.

Again, sorry for the delay.
Best regards,

Alex

[phuicy]

Ah you beat me to it. I was just here coming to comment that I have fixed it with the tag.

thanks,
Guy

[alexvannobel]

Hi,
I just merged the PR, I'll close the issue now.
Best regards,
Alex