joint angle: position and range

[fjp]

Hi, I have some more questions, regarding the joint angles (position):

1. The documentation states that diff_drive_controller works with wheel joints through a velocity interface. However, in your my_robot_hw_interface.h you read a position (angle) from the continuous wheel joints.

pos[0] += ang_distance_left;

Do you know why we need to provide the angle of the joints? I am asking because the mentioned documentation for diff_drive_controller is unclear to me. It seems to use only a velocity interface and no position interface.

2. What's the range that you put the angles in? [0, 2*pi[, [-pi, pi[ or something else? I am asking for a range because I found out that the angles get wrapped according to this github issue on ros_controllers. This means it shouldn't really matter if the angle increases but I would like to avoid an overflow, which might cause trouble?

Thanks for your time and help