Controlling two robots: please help me get started (Action client not connected: /follow_joint_trajectory)

**edit ---** [as of four years ago](https://groups.google.com/forum/#!topic/moveit-users/NZfk2PfnxWM) there was apparently no way to use MoveIt! with multiple robots, other than to combine them into a single URDF and treat them as one robot. This could work for me but then I guess the joints on the two robots would have to have different names for purposes of the controller? **initial content:** As an early attempt at simultaneously using two UR10s in a Gazebo simulation (and afterwards in the lab) I first modified the `universal_robot package files ur10.launch` and `ur10_moveit_planning_execution.launch` to use my own robot xacro (which at this stage is pretty much the same as `ur10_joint_limited_robot.urdf.xacro`). There are two launch files to get this simulation running and have MoveIt! operational. This initial step is working well. The next step in my plan for using two robots was to employ the `group` tag around this robot and around the `moveit_config/launch/move_group.launch` include as shown here in the two launch files. Here is the second launch file: The first one works as expected but the second one yields [ WARN] [1532698585.718194685, 368.013000000]: Waiting for /follow_joint_trajectory to come up [ WARN] [1532698591.765929321, 374.013000000]: Waiting for /follow_joint_trajectory to come up [ERROR] [1532698597.822045680, 380.018000000]: Action client not connected: /follow_joint_trajectory The only modification between these files and the two that work fine is the addition of the `` tag. Here are two questions. Can you say what the problem is with MoveIt! and can you tell me if this will be a good approach for using a second robot? I'm thinking that there will be a problem with `robot_state_publisher` since `tf` does not end up in the "placer" namespace (the topic is just `/tf`).