Robot joints going to 0 when launching Gazebo in ROS melodic

[MarcFacerias]

When executing the examples with xarm7 I get the error "No p gain specified for PID. Namespace: /xarm/gazebo_ros_control/pid_gains/joint2", which can be solved by uncommenting certain code in the YAML files, however, whenever I do that all the robot joints go to 0 and the simulator is unusable, how should I address it?

[penglongxiang]

Hi @MarcFacerias, the error "No P gain specified" actually does not affect the simulation under position control. If you must use the PID gains, maybe tuning has to be performed to make stable simulations in Gazebo.

[MarcFacerias]

Hello, @penglongxiang thank you for your response, my actual problem is that whenever I try to move the robot and locate it in another place within the simulation the model collapses, I thought the reason was some weird interaction between the PID controllers and colliding with an obstacle, but after your message, I understand that shouldn't cause that issue. You can find attached an image with its behaviour.

Thanks in advance e