Problem integrating trajectory controller and chainable interface

[pac48]

I have a controller which I would like to use in chained mode. I want it to accept the output of a trajectory controller as input. This line prevents it from working:

ros2_control/controller_interface/src/chainable_controller_interface.cpp

Line 70 in d632e89

if (interface.get_name() != get_node()->get_name())

The trajectory controller requires that the interface name contains "position" or "velocity" or both. As far as I can tell, you might be able to configure the trajectory controller command interfaces like this:

• my_controller_position_joint_1/my_controller
• my_controller_position_joint_2/my_controller
• ...
• my_controller_velocity_joint_1/my_controller
• my_controller_velocity_joint_2/my_controller
  I think it would be more compatible and straight forward if they were configured like this:
• position/my_controller_joint_1
• position/my_controller_joint_2
• ...
• velocity/my_controller_joint_1
• velocity/my_controller_joint_2

The fix is simple, just change the equality comparison if (interface.get_name() != get_node()->get_name()) to a contains comparison. Now that I take a closer look, it seems it was meant to be this way from the error message.

[pac48]

This should work if (interface.get_name().find(get_node()->get_name()) != std::string::npos)
Please let me know if I am misunderstanding this.

[pac48]

Okay, so there a few changed still waiting to be merged as of today which will enable the JTC. See ros-controls/ros2_controllers#318, ros-controls/ros2_control_demos#162, #667