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No, I would say you are not using the JointTrajectoryController in the way it is intended.
In a software-layer sense, it sits on top of a simple JointController. Conceptually, for each joint, this JointController takes 1 input (target_velocity) and produces 2 output (cur_position,cur_velocity). It is meant to be a very simple command interface. Note that I'm describing a velocity cmd interface; there are other types.
In a real robot, there is normally one JointController, with N inputs. Note that gazebo models this differently, using N one-input JointControllers. In the bigger picture, this difference is not important.
The higher level JointTrajectoryController exists to provide convenience for you, 1) it lets you specify a sequence of waypoints, and 2) it allows you to describe the time element for the arm's movement. In contrast, the lower level JointController is a "get to this velocity right now" cmd interface.
Lastly, the JointTrajectoryController is an Action Server. Your code is not really intended to directly subscribe to the goal topic. You can begin learning about actionlib at http://wiki.ros.org/actionlib
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No, I would say you are not using the JointTrajectoryController in the way it is intended.
In a software-layer sense, it sits on top of a simple JointController. Conceptually, for each joint, this JointController takes 1 input (target_velocity) and produces provides 2 output status outputs (cur_position,cur_velocity). It is meant to be a very simple command interface. Note that I'm describing a velocity cmd interface; there are other types.
In a real robot, there is normally one JointController, with N inputs. Note that gazebo models this differently, using N one-input JointControllers. In the bigger picture, this difference is not important.
The higher level JointTrajectoryController exists to provide convenience for you, 1) it lets you specify a sequence of waypoints, and 2) it allows you to describe the time element for the arm's movement. In contrast, the lower level JointController is a "get to this velocity right now" cmd interface.
Lastly, the JointTrajectoryController is an Action Server. Your code is not really intended to directly subscribe to the goal topic. You can begin learning about actionlib at http://wiki.ros.org/actionlib
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