[gazebo_plugins] Add vacuum gripper plugin #389
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Huge +1. This is so cool, @wkentaro! Well done generalizing the interface to a plugin as well. |
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| /* | |||
| * Copyright (C) 2012-2014 Open Source Robotics Foundation | |||
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This date could be updated to 2015-2016
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closing and re-opening to trigger CI builds |
| physics::Link_V links = models[i]->GetLinks(); | ||
| for (size_t j = 0; j < links.size(); j++) { | ||
| math::Pose link_pose = links[j]->GetWorldPose(); | ||
| math::Pose diff = parent_pose - link_pose; |
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This uses the difference in link pose between the end effector and an object to determine whether they are close enough for force to be applied, but this depends on where the coordinate frames are defined. This might work for small objects, but it would be better to use collision checking (such as ray-casting) to determine the proximity to the actual surface, which won't be affected by how coordinate frames are defined.
Let me know if that didn't make sense and we can discuss further.
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now I realize that you said exactly this in the description of the pull request
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Actually, I don't know how to get the distance between robot link and object collision for now.
Do you know how to do this? Or example?
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Wada San,
This is a wonderful , plugin and very helpful. How can I do a specific modification, such as applying force to the links position (x,y,z) with an offset, (x+10,y,z)
This way, I can solve a specifc problem, that I have, i.e. to apply force at the corners of a large cylindrical object, rather than applying force on the center of the cylinder?
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I think you should change the direction of the force.
https://github.com/ros-simulation/gazebo_ros_pkgs/blob/jade-devel/gazebo_plugins/src/gazebo_ros_vacuum_gripper.cpp#L210-L211
Currently the direction is from gripper link to object link.
| if (norm_force > 20) { | ||
| norm_force = 20; // max_force | ||
| } | ||
| math::Vector3 force = norm_force * diff.pos.Normalize(); |
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it also applies the force in every direction, when it should apply it in a single direction only. We would need a way to specify this direction to implement this
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Yeah, it should be.
Maybe, It will be not single direction but restricted.
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This is a working plugin even if it isn't perfect, as you stated. I'll be ready to merge this if the copyright year is updated. We can create an issue to address the other comments I made (poses of coordinate frames instead of collision proximity, directionality of force, parameterization). |
I will create a new pull request to fix the problem with the copyright. Thanks to everyone for the pull request. |
Thanks. |
Thanks for the review. I watch the issue on #446 and will work for this when I have time. |
this plugin is not perfect:
rrbot_sample:
baxter_sample: