enforce limits in ros_control hw interface

[gavanderhoorn]

The current implementation of the hardware_interface for ros_control does not appear to be checking nor enforcing joint limits.

This should be added.

PS: labelled as an enhancement, but perhaps this should really be considered a bug.

[gavanderhoorn]

From: ros-controls/ros_controllers#393 (comment).

[gavanderhoorn]

Joint limits for all controlled joints should also be parsed from the urdf/parameter server by the hardware_interface.

[davetcoleman]

Thanks for reporting @gavanderhoorn

Note we do have a joint_limit_interface in ros_control, it just needs to be integrated into the ur_modern_driver. Here's some example code