[Feature Request] - Allow to change compliance_ref_link in a loaded controller

[firesurfer]

Problem statement and motivation

Currently it is not possible to change to compliance_ref_link in an already loaded controller as it is not possible to reconfigure a controller once it is configured ( as far as know - see ros-controls/ros2_control#1033)

For larger setups with multiple robot arm which also have multiple tools which have to be compliant at some point the current solution of defining a controller per compliant link becomes messy quite easily.

Therefore it would be nice to just have a compliance controller per arm and being able to change to ref_link.

Goal of this feature

Being able to set the compliance_ref_link , deactivate -> active the controller and then use the changed ref_link

Approach and next steps

Simply move:

cartesian_controllers/cartesian_compliance_controller/src/cartesian_compliance_controller.cpp

Line 103 in 752a6a9

m_compliance_ref_link = get_node()->get_parameter("compliance_ref_link").as_string();

into the beginning of on_activate.

If desired I can also provide a PR for that.

[stefanscherzinger]

@firesurfer

Thanks for this feature request. I like the idea and will have a look.

[firesurfer]

@stefanscherzinger Great that you see it the same way. Give that I need this feature rather sooner then later I will try to workout a solution and create a PR.