In the preceding section, we discussed the pr2_mechanism packages which build the controllers for PR2. These packages are exclusively designed for PR2, but they will work in robots that are similar to PR2.
To make these packages more generic to all the robots, the pr2_mechanism packages rewritten and formed a new set of packages called ros_control (http://wiki.ros.org/ros_control).
The ros_control implement standard set of generic controllers such as effort_controllers, joint_state_controllers, position_controllers, and velocity controllers for any kind of robots.
We have already used these ROS controllers from ros_control in Chapter 3, Simulating Robots Using ROS and Gazebo. The ros_control is still in development. The building procedure of the controllers is almost similar to PR2 controllers.
You can go through the available wiki page of ros_control for building new controls at https://github.com/ros-controls/ros_control/wiki.
You will get a sample controller...
