add test urdf files

test/urdf/doublependulum.urdf

@@ -0,0 +1,64 @@
+<?xml version="1.0"?>
+
+<robot name="DoublePendulum">
+ <link name="base_link">
+ <visual>
+ <geometry>
+ <box size=".2 .2 .2" />
+ </geometry>
+ <material name="green">
+ <color rgba="0 1 0 1" />
+ </material>
+ </visual>
+ </link>
+
+ <link name="upper_link">
+ <inertial>
+ <origin xyz="0 0 -.5" rpy="0 0 0" />
+ <mass value="1" />
+ <inertia ixx="1" ixy="0" ixz="0" iyy="0.083" iyz="0" izz="1" />
+ </inertial>
+ <visual>
+ <origin xyz="0 0 -.5" rpy="0 0 0" />
+ <geometry>
+ <cylinder length="1.1" radius=".05" />
+ </geometry>
+ <material name="red">
+ <color rgba="1 0 0 1" />
+ </material>
+ </visual>
+ </link>
+
+ <link name="lower_link">
+ <inertial>
+ <origin xyz="0 0 -1" rpy="0 0 0" />
+ <mass value="1" />
+ <inertia ixx="1" ixy="0" ixz="0" iyy="0.33" iyz="0" izz="1" />
+ </inertial>
+ <visual>
+ <origin xyz="0 0 -1" rpy="0 0 0" />
+ <geometry>
+ <cylinder length="2.1" radius=".05" />
+ </geometry>
+ <material name="blue">
+ <color rgba="0 0 1 1" />
+ </material>
+ </visual>
+ </link>
+
+ <joint name="shoulder" type="continuous">
+ <parent link="base_link" />
+ <child link="upper_link" />
+ <origin xyz="0 .15 0" />
+ <axis xyz="1 0 0" />
+ <dynamics damping="0.1" />
+ </joint>
+
+ <joint name="elbow" type="continuous">
+ <parent link="upper_link" />
+ <child link="lower_link" />
+ <origin xyz="0 .1 -1" />
+ <axis xyz="1 0 0" />
+ <dynamics damping="0.1" />
+ </joint>
+</robot>