A monotonic time source should be used for calculating the update period passed into the controller manager. This ensures the period is always accurate, and isn't impacted by time smears or time jumps in the wall time. These irregularities in the wall time are not that uncommon, for example when the system time gets synchronized via NTP. ros::SteadyTime ensures these irregularities don't break the controller update calculations.
A monotonic time source should be used for calculating the update period passed into the controller manager. This ensures the period is always accurate, and isn't impacted by time smears or time jumps in the wall time. These irregularities in the wall time are not that uncommon, for example when the system time gets synchronized via NTP.
ros::SteadyTimeensures these irregularities don't break the controller update calculations.