Failed to load joint?_*_controller
Hello, I have ROS Hydro on Ubuntu 12.04.4.
I have made
$ sudo apt-get install ros-hydro-desktop-full
$ sudo apt-get install ros-hydro-gazebo-ros-pkgs ros-hydro-gazebo-ros-control
and I have downloaded the gazebo_ros_demos into my
catkin_ws/src
I want to try http://gazebosim.org/tutorials/?tut=r... .
Until I type
$ roslaunch rrbot_gazebo rrbot_world.launch
everything is fine.
But then, when I type
$ roslaunch rrbot_control rrbot_control.launch
then it says
[ERROR] [WallTime: 1403516339.376075] [33.377000] Failed to load joint_state_controller
[ERROR] [WallTime: 1403516340.379782] [34.378000] Failed to load joint1_position_controller
[ERROR] [WallTime: 1403516341.383720] [35.379000] Failed to load joint2_position_controller
What have I made wrong? What can I do, so that it works?