I am using ubuntu 22.04 humble ros2.
I am trying to run a robot with wheels on gazebo using the differential drive plugin from https://classic.gazebosim.org/tutorials?tut=ros_gzplugins. When i try to launch the gazebo file i get the following error
[gzserver-3] Error [Element.cc:914] Missing element description for [left_joint] [gzserver-3] Error [Element.cc:914] Missing element description for [right_joint] i have created a seperate control file and included it in my URDF
The control file looks like this
<?xml version="1.0" ?> <robot name="marsrover" xmlns:xacro="http://www.ros.org/wiki/xacro" > <gazebo> <plugin name="differential_drive_controller" filename="libgazebo_ros_diff_drive.so"> <!-- Plugin update rate in Hz --> <updateRate>100</updateRate> <!-- Name of left joint, defaults to `left_joint` --> <leftJoint>Revolute 8</leftJoint> <!-- Name of right joint, defaults to `right_joint` --> <rightJoint>Revolute 10</rightJoint> <!-- The distance from the center of one wheel to the other, in meters, defaults to 0.34 m --> <wheelSeparation>0.60</wheelSeparation> <!-- Diameter of the wheels, in meters, defaults to 0.15 m --> <wheelDiameter>0.26</wheelDiameter> <!-- Wheel acceleration, in rad/s^2, defaults to 0.0 rad/s^2 --> <wheelAcceleration>1.0</wheelAcceleration> <!-- Maximum torque which the wheels can produce, in Nm, defaults to 5 Nm --> <wheelTorque>50</wheelTorque> <!-- Topic to receive geometry_msgs/Twist message commands, defaults to `cmd_vel` --> <commandTopic>cmd_vel</commandTopic> <!-- Topic to publish nav_msgs/Odometry messages, defaults to `odom` --> <odometryTopic>odom</odometryTopic> <!-- Odometry frame, defaults to `odom` --> <odometryFrame>odom</odometryFrame> <!-- Robot frame to calculate odometry from, defaults to `base_footprint` --> <robotBaseFrame>base_link</robotBaseFrame> <!-- Odometry source, 0 for ENCODER, 1 for WORLD, defaults to WORLD --> <odometrySource>1</odometrySource> <!-- Set to true to publish transforms for the wheel links, defaults to false --> <publishWheelTF>true</publishWheelTF> <!-- Set to true to publish transforms for the odometry, defaults to true --> <publishOdom>true</publishOdom> <!-- Set to true to publish sensor_msgs/JointState on /joint_states for the wheel joints, defaults to false --> <publishWheelJointState>true</publishWheelJointState> <!-- Set to true to swap right and left wheels, defaults to true --> <legacyMode>false</legacyMode> </plugin> </gazebo> </robot> My URDF looks like this
<?xml version="1.0" ?> <robot name="marsrover" xmlns:xacro="http://www.ros.org/wiki/xacro"> <xacro:include filename="$(find marsrover_description)/urdf/materials.xacro" /> <xacro:include filename="$(find marsrover_description)/urdf/marsrover.trans" /> <xacro:include filename="$(find marsrover_description)/urdf/marsrover.gazebo" /> <xacro:include filename="$(find marsrover_description)/urdf/marsrover_control.xacro" /> <link name="base_link"> <inertial> <origin xyz="0.1079014386962853 -0.018704254362633656 0.6454702576619512" rpy="0 0 0"/> <mass value="1123.0178027625177"/> <inertia ixx="42.702699" iyy="66.247576" izz="91.981429" ixy="-2.722801" iyz="0.096354" ixz="1.746058"/> </inertial> <visual> <origin xyz="0 0 0" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/base_link.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="0 0 0" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/base_link.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="rightleg_big_1"> <inertial> <origin xyz="0.08026176688942216 0.02500033810921609 -0.15057691313293592" rpy="0 0 0"/> <mass value="22.546629703835407"/> <inertia ixx="0.328749" iyy="2.046875" izz="1.727521" ixy="0.0" iyz="-0.0" ixz="0.322481"/> </inertial> <visual> <origin xyz="-0.028011 -0.292969 -0.648297" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/rightleg_big_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="-0.028011 -0.292969 -0.648297" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/rightleg_big_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="leftleg_big_1"> <inertial> <origin xyz="0.08026176688941755 -0.02499966189078373 -0.1505769131329358" rpy="0 0 0"/> <mass value="22.546629703835407"/> <inertia ixx="0.328749" iyy="2.046875" izz="1.727521" ixy="0.0" iyz="-0.0" ixz="0.322481"/> </inertial> <visual> <origin xyz="-0.028011 0.347031 -0.648297" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/leftleg_big_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="-0.028011 0.347031 -0.648297" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/leftleg_big_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="rightleg_small_1"> <inertial> <origin xyz="-0.0641436530031968 0.02500033810921981 -0.0835318655770268" rpy="0 0 0"/> <mass value="21.006548439283524"/> <inertia ixx="0.162855" iyy="1.268194" izz="1.114091" ixy="0.0" iyz="-0.0" ixz="0.048486"/> </inertial> <visual> <origin xyz="0.396172 -0.342969 -0.41332" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/rightleg_small_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="0.396172 -0.342969 -0.41332" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/rightleg_small_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="leftleg_small_1"> <inertial> <origin xyz="-0.07117981414108449 -0.02499966189077979 -0.07762348003982011" rpy="0 0 0"/> <mass value="21.006548439283524"/> <inertia ixx="0.178501" iyy="1.268194" izz="1.098446" ixy="0.0" iyz="-0.0" ixz="0.130339"/> </inertial> <visual> <origin xyz="0.396172 0.397031 -0.41332" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/leftleg_small_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="0.396172 0.397031 -0.41332" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/leftleg_small_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="wheel2_1"> <inertial> <origin xyz="4.6187777968942356e-07 -0.08499966189077818 2.1514828360547078e-07" rpy="0 0 0"/> <mass value="24.630675452766535"/> <inertia ixx="0.231272" iyy="0.343906" izz="0.231272" ixy="0.0" iyz="0.0" ixz="-0.0"/> </inertial> <visual> <origin xyz="0.729843 0.447031 -0.156291" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/wheel2_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="0.729843 0.447031 -0.156291" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/wheel2_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="wheel1_1"> <inertial> <origin xyz="-3.179377151552032e-07 0.08500033810922158 -5.305311800984924e-08" rpy="0 0 0"/> <mass value="24.630675452766535"/> <inertia ixx="0.231272" iyy="0.343906" izz="0.231272" ixy="0.0" iyz="-0.0" ixz="-0.0"/> </inertial> <visual> <origin xyz="0.706171 -0.392969 -0.128188" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/wheel1_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="0.706171 -0.392969 -0.128188" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/wheel1_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="wheel4_1"> <inertial> <origin xyz="2.529740886214604e-07 0.08500033810921648 3.7330526453382973e-07" rpy="0 0 0"/> <mass value="24.630675452766535"/> <inertia ixx="0.231272" iyy="0.343906" izz="0.231272" ixy="0.0" iyz="-0.0" ixz="0.0"/> </inertial> <visual> <origin xyz="0.052627 -0.392969 -0.175811" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/wheel4_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="0.052627 -0.392969 -0.175811" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/wheel4_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="wheel26_1"> <inertial> <origin xyz="-7.933437029539192e-08 0.0850003381092132 3.1630714458774634e-07" rpy="0 0 0"/> <mass value="24.630675452766535"/> <inertia ixx="0.231272" iyy="0.343906" izz="0.231272" ixy="0.0" iyz="0.0" ixz="0.0"/> </inertial> <visual> <origin xyz="-0.434229 -0.342969 -0.191392" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/wheel26_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="-0.434229 -0.342969 -0.191392" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/wheel26_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="wheel3_1"> <inertial> <origin xyz="-2.4651678172393776e-07 -0.08499966189078317 2.5749494830806796e-07" rpy="0 0 0"/> <mass value="24.630675452766535"/> <inertia ixx="0.231272" iyy="0.343906" izz="0.231272" ixy="0.0" iyz="-0.0" ixz="0.0"/> </inertial> <visual> <origin xyz="0.074634 0.447031 -0.146773" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/wheel3_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="0.074634 0.447031 -0.146773" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/wheel3_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="wheel5_1"> <inertial> <origin xyz="-7.933437534690668e-08 -0.08499966189078612 3.1630714411590155e-07" rpy="0 0 0"/> <mass value="24.630675452766535"/> <inertia ixx="0.231272" iyy="0.343906" izz="0.231272" ixy="0.0" iyz="-0.0" ixz="0.0"/> </inertial> <visual> <origin xyz="-0.434229 0.397031 -0.191392" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/wheel5_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="-0.434229 0.397031 -0.191392" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/wheel5_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="rightleglink_1"> <inertial> <origin xyz="-0.3354348448034716 0.032519338109216644 -0.666434058596638" rpy="0 0 0"/> <mass value="0.16957453765781244"/> <inertia ixx="0.000188" iyy="0.000192" izz="6e-06" ixy="0.0" iyz="0.0" ixz="4e-06"/> </inertial> <visual> <origin xyz="-0.363607 -0.31545 -1.399928" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/rightleglink_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="-0.363607 -0.31545 -1.399928" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/rightleglink_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="leftleglink_1"> <inertial> <origin xyz="0.40452915519652305 -0.027480661890782798 -0.659159058596637" rpy="0 0 0"/> <mass value="0.16957453765781244"/> <inertia ixx="0.000188" iyy="0.000192" izz="6e-06" ixy="0.0" iyz="-0.0" ixz="4e-06"/> </inertial> <visual> <origin xyz="0.376357 0.37455 -1.392653" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/leftleglink_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="0.376357 0.37455 -1.392653" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/leftleglink_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="boggiemiddleshit_1"> <inertial> <origin xyz="0.13875725093888558 0.027030338109217733 -0.5040354381025404" rpy="0 0 0"/> <mass value="0.036370775253551875"/> <inertia ixx="2e-06" iyy="2e-06" izz="1e-06" ixy="-0.0" iyz="0.0" ixz="-0.0"/> </inertial> <visual> <origin xyz="0.215019 0.054061 -1.316123" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/boggiemiddleshit_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="0.215019 0.054061 -1.316123" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/boggiemiddleshit_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="leftboggielink_1"> <inertial> <origin xyz="0.05639229827838968 9.925958193768292e-06 -0.015470958365142118" rpy="0 0 0"/> <mass value="0.16957453765781244"/> <inertia ixx="1e-05" iyy="0.00019" izz="0.000186" ixy="-1.6e-05" iyz="2e-06" ixz="1.9e-05"/> </inertial> <visual> <origin xyz="0.075908 -0.342969 -0.822081" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/leftboggielink_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="0.075908 -0.342969 -0.822081" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/leftboggielink_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="rightboggielink_1"> <inertial> <origin xyz="0.05639079038116439 -9.154467956962176e-06 -0.015476453623781805" rpy="0 0 0"/> <mass value="0.16957453765781244"/> <inertia ixx="1e-05" iyy="0.00019" izz="0.000186" ixy="1.6e-05" iyz="-2e-06" ixz="1.9e-05"/> </inertial> <visual> <origin xyz="0.075908 0.397031 -0.822081" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/rightboggielink_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="0.075908 0.397031 -0.822081" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/rightboggielink_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <link name="bigboggie_1"> <inertial> <origin xyz="0.00017673760116454496 3.3810921771723623e-07 0.004997178425846904" rpy="0 0 0"/> <mass value="2.133721996073983"/> <inertia ixx="0.097387" iyy="0.000258" izz="0.097608" ixy="-0.0" iyz="0.0" ixz="8e-06"/> </inertial> <visual> <origin xyz="0.075908 0.027031 -0.822081" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/bigboggie_1.stl" scale="0.001 0.001 0.001"/> </geometry> <material name="silver"/> </visual> <collision> <origin xyz="0.075908 0.027031 -0.822081" rpy="0 0 0"/> <geometry> <mesh filename="file://$(find marsrover_description)/meshes/bigboggie_1.stl" scale="0.001 0.001 0.001"/> </geometry> </collision> </link> <joint name="Revolute 1" type="fixed"> <origin xyz="0.028011 0.292969 0.648297" rpy="0 0 0"/> <parent link="base_link"/> <child link="rightleg_big_1"/> <axis xyz="0.0 1.0 -0.0"/> </joint> <joint name="Revolute 2" type="fixed"> <origin xyz="0.028011 -0.347031 0.648297" rpy="0 0 0"/> <parent link="base_link"/> <child link="leftleg_big_1"/> <axis xyz="-0.0 -1.0 0.0"/> </joint> <joint name="Revolute 3" type="continuous"> <origin xyz="-0.424183 0.05 -0.234977" rpy="0 0 0"/> <parent link="rightleg_big_1"/> <child link="rightleg_small_1"/> <axis xyz="0.0 1.0 -0.0"/> </joint> <joint name="Revolute 4" type="continuous"> <origin xyz="-0.424183 -0.05 -0.234977" rpy="0 0 0"/> <parent link="leftleg_big_1"/> <child link="leftleg_small_1"/> <axis xyz="-0.0 -1.0 0.0"/> </joint> <joint name="Revolute 6" type="continuous"> <origin xyz="-0.333671 -0.05 -0.257029" rpy="0 0 0"/> <parent link="leftleg_small_1"/> <child link="wheel2_1"/> <axis xyz="-0.0 -1.0 0.0"/> </joint> <joint name="Revolute 7" type="continuous"> <origin xyz="-0.309999 0.05 -0.285132" rpy="0 0 0"/> <parent link="rightleg_small_1"/> <child link="wheel1_1"/> <axis xyz="0.0 1.0 -0.0"/> </joint> <joint name="Revolute 8" type="continuous"> <origin xyz="0.343545 0.05 -0.237509" rpy="0 0 0"/> <parent link="rightleg_small_1"/> <child link="wheel4_1"/> <axis xyz="0.0 1.0 -0.0"/> </joint> <joint name="Revolute 9" type="continuous"> <origin xyz="0.406218 0.05 -0.456905" rpy="0 0 0"/> <parent link="rightleg_big_1"/> <child link="wheel26_1"/> <axis xyz="0.0 1.0 -0.0"/> </joint> <joint name="Revolute 10" type="continuous"> <origin xyz="0.321538 -0.05 -0.266547" rpy="0 0 0"/> <parent link="leftleg_small_1"/> <child link="wheel3_1"/> <axis xyz="-0.0 -1.0 0.0"/> </joint> <joint name="Revolute 11" type="continuous"> <origin xyz="0.406218 -0.05 -0.456905" rpy="0 0 0"/> <parent link="leftleg_big_1"/> <child link="wheel5_1"/> <axis xyz="-0.0 -1.0 0.0"/> </joint> <joint name="Rigid 13" type="fixed"> <origin xyz="0.008429 0.055 0.142869" rpy="0 0 0"/> <parent link="rightleg_big_1"/> <child link="rightleglink_1"/> </joint> <joint name="Rigid 14" type="fixed"> <origin xyz="0.008429 -0.055 0.142869" rpy="0 0 0"/> <parent link="leftleg_big_1"/> <child link="leftleglink_1"/> </joint> <joint name="Rigid 20" type="fixed"> <origin xyz="-0.215019 -0.054061 1.316123" rpy="0 0 0"/> <parent link="base_link"/> <child link="boggiemiddleshit_1"/> </joint> <joint name="Ball 21" type="continuous"> <origin xyz="0.0 0.37 0.0" rpy="0 0 0"/> <parent link="bigboggie_1"/> <child link="leftboggielink_1"/> <axis xyz="-0.0 -1.0 0.0"/> </joint> <joint name="Ball 22" type="continuous"> <origin xyz="0.0 -0.37 0.0" rpy="0 0 0"/> <parent link="bigboggie_1"/> <child link="rightboggielink_1"/> <axis xyz="-0.0 -1.0 0.0"/> </joint> <joint name="Ball 23" type="continuous"> <origin xyz="0.112348 -0.005 -0.030915" rpy="0 0 0"/> <parent link="rightboggielink_1"/> <child link="rightleglink_1"/> <axis xyz="-0.0 -1.0 0.0"/> </joint> <joint name="Ball 24" type="continuous"> <origin xyz="0.112348 0.005 -0.030915" rpy="0 0 0"/> <parent link="leftboggielink_1"/> <child link="leftleglink_1"/> <axis xyz="-0.0 -1.0 0.0"/> </joint> <joint name="Revolute 25" type="fixed"> <origin xyz="0.139111 0.02703 -0.494042" rpy="0 0 0"/> <parent link="boggiemiddleshit_1"/> <child link="bigboggie_1"/> <axis xyz="0.035366 0.0 0.999374"/> </joint> </robot> 
