mikeferguson / moveit_python

moveit_python

This is a set of pure-python bindings to the ROS interface of MoveIt! based on the earlier moveit_utils package that was developed as part of the chess_player package.

Overview

There are three interfaces currently:

• MoveGroupInterface -- used to move the arm using the move_group action.
• PlanningSceneInterface -- used to add/remove collision and attached objects. Can also set the colors of objects.
• PickPlaceInterface -- used to interface to the pick and place actions.

MoveGroupInterface

The MoveGroupInterface is quite easy to use:

import rospy
from moveit_python import *

rospy.init_node("moveit_py")
g = MoveGroupInterface("planning_group_name", "base_link")

Obviously, you might need different values for base_link, and your planning group is probably not called "planning_group_name".

PlanningSceneInterface

The PlanningSceneInterface allows you to easily insert and remove objects from the MoveIt! planning scene. Starting with version 0.3.0, this module will try to use the newer service-based approach to apply planning scene updates, as this is much more robust than publishing messages over topics asynchronously.

import rospy
from moveit_python import *

rospy.init_node("moveit_py")
# create a planning scene interface, provide name of root link
p = PlanningSceneInterface("base_link")

# add a cube of 0.1m size, at [1, 0, 0.5] in the base_link frame
p.addCube("my_cube", 0.1, 1, 0, 0.5)

# do something

# remove the cube
p.removeCollisionObject("my_cube")

If for some reason you would prefer to not use the service, simply set "use_service" to false in the various add/remove calls. Calling waitForSync will republish messages as needed to synchronize the planning scene between your script and MoveIt.

p.addCube("my_cube", 0.1, 1, 0, 0.5, use_service=False)
p.addCube("my_other_cube", 0.1, 2, 0, 0.5, use_service=False)
p.waitForSync()

PickPlaceInterface

import rospy
from moveit_python import *
from moveit_msgs.msg import Grasp, PlaceLocation

rospy.init_node("moveit_py")
# provide arm group and gripper group names
# also takes a third parameter "plan_only" which defaults to False
p = PickPlaceInterface("arm", "gripper")

g = Grasp()
# fill in g
# setup object named object_name using PlanningSceneInterface
p.pickup("object_name", [g, ], support_name = "supporting_surface")

l = PlaceLocation()
# fill in l
p.place("object_name" [l, ], goal_is_eef = True, support_name = "supporting_surface")

Migration from moveit_utils

• GraspingInterface renamed to PickPlaceInterface
  • The pick/place functions now return the entire action result, in moveit_utils they returned only the error_code. To access the error code as it used to be returned, you would use result.error_code.val
• ObjectManager renamed to PlanningSceneInterface
  • remove function is now removeCollisionObject and removeAttachedObject
• ArmInterface renamed to MoveGroupInterface