PR2 fingertip pressure in gazebo simulator

edit

I am trying to observe the fingertip pressure in the gazebo simulator.

This problem is close to one that discussed here: ros-users.122217.n3.nabble.com/questions-about-pr2-fingertip-pressure-td989401.html ; somebody made a script to transfer the gazebo's pressure sensor into PR2 topic. Now, that script is found in the pr2_gazebo package:

/opt/ros/groovy/stacks/pr2_simulator/pr2_gazebo/scripts/pr2_fingertip_pressure_contact_translator.py

But, it does not work. When I executed this script, it sent values to the /pressure/r_gripper_motor topic, but the values were just a zero vector:

$ rostopic echo /pressure/r_gripper_motor
...
l_finger_tip: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
r_finger_tip: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

I checked the source code, and found the problem; the original fingertip pressure measured in gazebo is obtained from /r_gripper_r_finger_tip_bumper or similar name topics, but no values are sent to these topics. From a similar topic named /base_bumper, I can observe values, so, there seems to be some troubles in finger tip bumpers.

Can someone help me to solve this problem? Or, is this problem already solved?

Note: I did not mention to avoid confusing that I slightly modified the original pr2_fingertip_pressure_contact_translator.py script. Originally, it refers to /r_gripper_r_finger_tip_bumper/state, but there are no topics named like that. So, I removed /state. In addition, originally ContactState and ContactsState are imported from gazebo_plugins.msg, but I changed to import from gazebo_msgs.msg since ContactState is not contained in gazebo_plugins.msg.