gazebo_ros_vacuum_gripper not working as expected

asked 2016-10-25 15:43:57 -0500

JoshMarino gravatar image

updated 2016-10-25 15:47:53 -0500

Hello there,

I am trying to use the gazebo_ros_vacuum_gripper plugin from gazebo_ros_pkgs in Jade. My URDF can be found here. Basically it is a box that starts out roughly 0.5 m above ground and then gravity pulls it downward. On the underside of my box, I have added a link/joint for the vacuum_gripper.

I am able to turn the grasping service on and it notifies me on the topic /Gecko_2/vacuum_gripper that it is grasping. However, if I apply a body force in Gazebo that is just larger than the weight of the box, the box moves upward off the ground plane in Gazebo. When this occurs, the state of /Gecko_2/vacuum_gripper stays True (grasping).

This should not happen from my understanding of the vacuum_gripper. Is there something I am doing wrong?

I want to be able to extend this example to a walking robot in which each leg will be attached to the ground_plane through a vacuum_gripper.

Any help would be appreciated, including going about this a different way. I looked into gazebo/physics/gripper.cc, but have not yet tried. It appears to create a fixedJoint between the gripper and the grasping object for a certain amount of time.

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Comments

This seems like it's more a Gazebo question (so should be asked there), but @wkentaro?

gvdhoorn gravatar imagegvdhoorn ( 2016-10-26 00:51:36 -0500 )edit

See Need help to trigger the vacuum gripper? for a related question btw.

gvdhoorn gravatar imagegvdhoorn ( 2016-10-26 00:52:38 -0500 )edit
JoshMarino gravatar imageJoshMarino ( 2016-10-27 17:03:45 -0500 )edit

gvdhoorn, sir, I have one more question sir , what needs to be done to let gripper pull objects on collision, I mean applying force on any other part of the object rather than just center of mass?

I am asking similar question as this one,

https://github.com/ros-simulation/gaz...

Abdullah gravatar imageAbdullah ( 2016-10-31 14:15:14 -0500 )edit

I'm not the author of the plugin, @wkentaro is. Perhaps he can help you.

gvdhoorn gravatar imagegvdhoorn ( 2016-10-31 15:04:40 -0500 )edit