Publish additional information

[costashatz]

Publish additional information:

• External torques
• Commanded torques
• Commanded positions

This is WIP...

[costashatz]

@JimmyDaSilva sorry for taking too long to merge this. I managed to perform some tests and it is working like a charm. I will fix the conflicts and merge. Thanks for this again!

[matthias-mayr]

I merged this into master on my fork and it works for me. Is there something else that should be checked before merging it?

[costashatz]

Is there something else that should be checked before merging it?

Nothing really. Have you experienced any lag or weird issue?

I haven't found time to test it thoroughly. If you tell it is OK, I will merge now..

[matthias-mayr]

I double-checked published values with the ones on the SmartPad.
I also plotted the external torque and pushed the robot. The plot looked reasonable.

Maybe @JimmyDaSilva has some more experience with the other information.

[JimmyDaSilva]

Hi guys. Actually, I quit using iiwa_ros because I had too many issues with hard real-time control, as mentioned here #36.
I have used the "Additional outputs" back then and the values were great.

I remember investigating if my latency issues were coming from this PR.
My issues appeared using both the master branch and this PR, and I think with the same consistency.
This is no thorough proof, but I think this PR is ok. Especially thanks to the use of the realtime_tools::Publisher

[JimmyDaSilva]

Although, it seems the realtime_tools::Publisher cannot be used with control frequencies higher than 750Hz because of ros-controls/realtime_tools#23

[costashatz]

@JimmyDaSilva @matthias-mayr thank you for your comments.. I will merge asap!