The Transformation system needs to be up and running before we can do SLAM.
/tf is a ROS standard method of tracking the position of multiple joint spaces on a robot like the PR2. We don't need anything that complex but all our data needs /tf's timestamping function and the ability to transform. This is useful so that the sonar data can be related to the heading data and corrected so that a sonar scan will always point in the right direction, no matter what heading the sub is at.
The Transformation system needs to be up and running before we can do SLAM.
/tf is a ROS standard method of tracking the position of multiple joint spaces on a robot like the PR2. We don't need anything that complex but all our data needs /tf's timestamping function and the ability to transform. This is useful so that the sonar data can be related to the heading data and corrected so that a sonar scan will always point in the right direction, no matter what heading the sub is at.