TF (nan value) error in revolute joints (in RViz)
hi . this is my URDF file . when i load this file in Rviz i have error :
[ERROR] [1481984390.816723728]: Ignoring transform for child_frame_id "link_U42_1" from authority "unknown_publisher" because of a nan value in the transform (-nan -nan -nan) (-nan -nan -nan -nan)
why i have this error ??!! please help me !
my URDF :
<?xml version="1.0"?>
<robot name="wrist">
<link name="link_U20_1">
<inertial>
<origin xyz="-2.77555756156289E-17 0 0" rpy="0 0 0" />
<mass value="0.714108712017557" />
<inertia ixx="0" ixy="0" ixz="0" iyy="0" iyz="0" izz="0" />
</inertial>
<visual>
<origin xyz="0 0 0" rpy="0 0 0" />
<geometry>
<mesh filename="file:///home/zakizadeh/catkin_ws3/src/wrist/meshes/link_U20_1.STL" />
</geometry>
<material name="">
<color rgba="0.792156862745098 0.819607843137255 0.933333333333333 1" />
</material>
</visual>
<collision>
<origin xyz="0 0 0" rpy="0 0 0" />
<geometry>
<mesh filename="file:///home/zakizadeh/catkin_ws3/src/wrist/meshes/link_U20_1.STL" />
</geometry>
</collision>
</link>
<link name="link_U42_1">
<inertial>
<origin xyz="0.000247437219810132 5.31436322726009E-09 0.000888814314510933" rpy="0 0 0" />
<mass
value="0.0318119469876036" />
<inertia ixx="0" ixy="0" ixz="0" iyy="0" iyz="0" izz="0" />
</inertial>
<visual>
<origin xyz="0 0 0" rpy="0 0 0" />
<geometry>
<mesh filename="file:///home/zakizadeh/catkin_ws3/src/wrist/meshes/link_U42_1.STL" />
</geometry>
<material name="">
<color rgba="0.792156862745098 0.819607843137255 0.933333333333333 1" />
</material>
</visual>
<collision>
<origin xyz="0 0 0" rpy="0 0 0" />
<geometry>
<mesh filename="file:///home/zakizadeh/catkin_ws3/src/wrist/meshes/link_U42_1.STL" />
</geometry>
</collision>
</link>
<joint name="joint_U42_1" type="revolute">
<origin xyz="0.0235 0.0005 -0.00700000000000001" rpy="1.5707963267949 0 1.5707963267949" />
<parent link="link_U20_1" />
<child link="link_U42_1" />
<axis xyz="0 0 0" />
<limit effort="1.0" lower="-2.53" upper="2.53" velocity="1.571"/>
</joint>
This is basically a duplicate of how change fixed joint to revolute joint in URDF ?.
i closed that question