fix URDF xacro files following the URDF conventions

upload the URDF to ROS parameter server using the origin URDF files

roslaunch iiwa_description iiwa7_upload.launch

run the following test script test.py

#!/usr/bin/env python

import kdl_parser_py.urdf
from urdf_parser_py.urdf import URDF
from kdl_parser_py.urdf import treeFromUrdfModel
import rospy


def main():

    robot_description = URDF.from_parameter_server()

    (ok, tree) = treeFromUrdfModel(robot_description) # get KDL tree from URDF
    chain = tree.getChain("world", "iiwa_link_7") # get KDL chain from kdl tree

    print("Number of segments is: {}".format(chain.getNrOfSegments()))


if __name__ == "__main__":
    main()

we will get the following warnings about URDF:

Unknown tag: material
Unknown tag: self_collision_checking
Unknown tag: material
Unknown tag: material
Unknown tag: material
Unknown tag: material
Unknown tag: material
Unknown tag: material
Unknown tag: material
Unknown tag: hardwareInterface
Unknown tag: robotNamespace
Unknown tag: hardwareInterface
Unknown tag: robotNamespace
Unknown tag: hardwareInterface
Unknown tag: robotNamespace
Unknown tag: hardwareInterface
Unknown tag: robotNamespace
Unknown tag: hardwareInterface
Unknown tag: robotNamespace
Unknown tag: hardwareInterface
Unknown tag: robotNamespace
Unknown tag: hardwareInterface
Unknown tag: robotNamespace
Number of segments is: 8

Reference

• URDF Transmission
• URDF Link