Why such a long default duration?

[awesomebytes]

I've noticed that when asking for a pick plan my gripper time_to_start times get this time added which makes the closing of the gripper very slow.
As I don't fully understand the need of this value (there is one most probably) I propose lowering it.

[isucan]

This duration really depends on how slow your gripper is. The correct fix would be to make this a dynamic parameter.

[awesomebytes]

Ok, maybe the problem here is that this time is added to the time you specify on the grasp (pre_grasp_posture and grasp_posture).
So I put on my grasp message:
grasp_data.pre_grasp_posture.points[0].time_from_start = ros::Duration(3,0);
grasp_data.grasp_posture.points[0].time_from_start = ros::Duration(4,0);

So I'm expecting to wait for 3s when doing the pre_grasp_posture, and for 4s for the grasp_posture

But on execution the goal sent to the gripper controller (a hand in our case) is (for the pre_grasp_posture):

joint_names: ['hand_right_index_joint', 'hand_right_middle_joint', 'hand_right_thumb_joint']
points:
-
positions: [0.10000347159257128, 0.10000347318852754, 0.09998135899197091]
velocities: [0.0, 0.0, 0.0]
accelerations: [0.0, 0.0, 0.0]
effort: []
time_from_start:
secs: 7
nsecs: 0
-
positions: [0.0, 0.0, 1.3]
velocities: [0.0, 0.0, 0.0]
accelerations: [0.0, 0.0, 0.0]
effort: []
time_from_start:
secs: 10
nsecs: 0
path_tolerance: []
goal_tolerance: []
goal_time_tolerance:
secs: 0
nsecs: 0

This is set here: https://github.com/ros-planning/moveit_ros/blob/hydro-devel/manipulation/pick_place/src/plan_stage.cpp#L88
pre_approach_traj->addPrefixWayPoint(pre_approach_state, PickPlace::DEFAULT_GRASP_POSTURE_COMPLETION_DURATION);

My first focus is to make this work on my robot, so changing that to 1.0s made the trick. I see it's only used for opening and closing the gripper. Shouldn't then the time_to_start field of a grasp be checked somewhere and if it's 0 then add this default value? Cause right now it seems it's adding it all the time.

Sorry if I'm not so clear explaining myself! But I'm tinkering around a lot for making the pick work (later on the place... and pick and place I hope).

[hersh]

Closing this pull request, as #443 seems like a better solution.