Writing a basic joint controller in ROS

The basic prerequisites for writing an ROS controller are already installed. We have discussed the underlying concepts of controllers. Now we can start creating a package for our own controller.

We are going to develop a controller that can access a joint of the robot and move the robot in a sinusoidal fashion. In particular, the first joint of the seven_dof_arm will follow a sinusoidal motion.

The procedure of building a controller is similar to other plugins development that we have seen earlier. The list of procedures to create an ROS controller is given as follows:

1. Create an ROS package with the necessary dependencies.
2. Write controller code in C++.
3. Register or export the C++ class as a plugin.
4. Define the plugin definition in an XML file.
5. Edit the  CMakeLists.txt  and package.xml files for exporting the plugin.
6. Write the configuration for our controller.
7. Load the controller using the controller manager.

Step 1 - Creating the controller package

The first step...