How to use pure position control rather than impedance control?

[Yitian-Xian]

Hi all, this is a very useful and stable package, I would like to thank all the authors and contributors!

When I am using the DirectServo, I found that with end-effector, the robot may drop a little and then return to the desired position. Especially for flange pivoting, the position of flange may differ from 2-3 mm, which is what I do not want. This is very similar to the question described in another package: epfl-lasa/iiwa_ros#56.

Does anyone have any idea on how to modify the control mode into pure position control? Thank you!

Best,
Yitian