UR5 is too stiff when robot is freedrive mode.

[JaeJun LEE]

Hello, I tried to use universal robot package with UR5(CB2).

I followed this page. 

http://wiki.ros.org/ur_c_api_bringup

It worked well.

But there is a problem. 

When robot is freedrive mode(with pressing extra button), robot is too stiff such that I can't move it easily.

When using teaching pendent, the robot was light and moved with small force.

Is there anyone who is suffering from same problem?

[Jacco van der Spek]

From my experience, you can't used the freedrive mode once you have connected the ROS driver. 

So it is true that you can't move it easily.

[G.A. vd. Hoorn - 3ME]

On 15-1-2015 12:31, Jacco van der Spek wrote:
> From my experience, you can't used the freedrive mode once you have
> connected the ROS driver.
> So it is true that you can't move it easily.

@Jacco:

While your statement is true in case of the URScript based driver in the
'ur_driver' package, the C-API based driver that JaeJun is referring to
seems to include support for the FREEDRIVE_MODE of the UR (see
ur_ctrlr_server/src/ur_hardware_controller.cpp#L135-143).

@JaeJun:

I think only Kelsey Hawkins can answer your question fully.

Also: I'm not sure which repository/branch you are using, but it looks
like the gt-ros-pkg/universal_robot fork contains many more recent
commits from Kelsey.


Gijs

[JaeJun LEE]

Thank you.

Yes I think, freedrive that used in URScript Mode and another one used in UR-C-API is different.

I thought URScript Interface was made using UR-C-API, am I wrong?

[JaeJun LEE]

Thank you, gavanderhoorn.

I'm using hydro-c-api-ur10-moveit branch.

 

[G.A. vd. Hoorn - 3ME]

On 15-1-2015 14:11, JaeJun LEE wrote:
> Thank you.
>
> Yes I think, freedrive that used in URScript Mode and another one used in
> UR-C-API is different.

I think what Jacco was trying to say is that enabling freedrive using
the TP is essentially impossible, as the URScript program in the
'ur_driver' pkg is interfering with it.

> I thought URScript Interface was made using UR-C-API, am I wrong?

Afaik, Polyscope (a Java program) uses sockets to communicate with the
URControl daemon running on the UR controller. It sends URScript
programs to URControl for execution in the URScript VM (?) (similar to
how you can send your own programs to port 30002). It would make sense
for both the C-API and the URScript VM to control the freedrive
functionality in a similar way, but I think only UR can really answer that.