Re: gps adapted to baxter

[Chelsea Finn]

Hi Qinglong,

For future questions, please email gps-help (CC'ed)

>>   1. In hyperparams.py, I found there is a parameter called EE_Points with a 3x3 array. What do those 9 numbers represent? Also, when you compute your sensor dimensions,you multiply EE_POINTS by 3, what does this multiplication mean?

The end-effector points are coordinates of 3 points on the robot's grippper in 3D. There are 3 points, and we multiply that by 3 because we are operating in 3D.

>> But how is this information used by PR2 to actually move the arm? I imagine there is one more node that processes all this data to produce a final joint angle update to PR2?

All of the PR2 controller code is in src/gps_agent_pkg.

>> I found that gazebo published not only the gps_controller_report after 100 steps, but also published it at every step, which seems pointless, can you explain why is it done?

Sometimes, you only want to know the information about the robot's pose at a single timestep. For example, it is useful to see what the current pose of the arm when setting the target.

Chelsea

On Mon, Jan 9, 2017 at 1:32 AM, 人生☆如水～ <smai...@qq.com> wrote:

Dear Chelsea:
  Thank you for opening your gps code on github
  We are an university group in China that is trying to adapt your gps code to baxter, and we came across some problems:

  1. In hyperparams.py, I found there is a parameter called EE_Points with a 3x3 array. What do those 9 numbers represent? Also, when you compute your sensor dimensions,you multiply EE_POINTS by 3, what does this multiplication mean?


  2. With regards to the way you move pr2 at every step, I see that in your code you publish trial_command. I see that the command includes data for policy, length of steps, starting position and final position, etc. But how is this information used by PR2 to actually move the arm? I imagine there is one more node that processes all this data to produce a final joint angle update to PR2? We have not yet understood this.

  3. I found that gazebo published not only the gps_controller_report after 100 steps, but also published it at every step, which seems pointless, can you explain why is it done?

Thank you so much for your time!
I apprecite it.
   Qinglong