Enable Gravity for Baxter

[davetcoleman]

Gravity is only enabled for the base of the robot and not the arms, see comment. Is there a reason for this? I think it should be enabled again

[davetcoleman]

Clarification after further investigation... in the baxter.urdf.xacro file gravity is by default enabled for all links. However, on initialization of the simulator, the baxter_emulator node permanently disables gravity on the arm links so as to "eliminate the need for gravity compensation". However, I think this is a poor hack in that, if you disable the robot, gravity will still be disabled.

Is there a reason KDL wasn't used to properly do gravity compensation in the simulated robot?