我试图让我的四轮机器人在仿真包Gazebo以及RViz中移动。
我已经为Gazebo，Rviz和robot_control创建了必要的.launch文件，但仍然看不到任何与车轮关节相关的主题。
当我尝试启动控制器时，出现以下警告/错误：
[ WARN] [1583095864.913036340]: The root link base_link has an inertia specified in the URDF, but KDL does not support a root link with an inertia. As a workaround, you can add an extra dummy link to your URDF.
[INFO] [1583095865.315061, 0.000000]: Controller Spawner: Waiting for service controller_manager/load_controller
0x1a2e560 void QWindowPrivate::setTopLevelScreen(QScreen*, bool) ( QScreen(0xfe3480) ): Attempt to set a screen on a child window.
0x1a22620 void QWindowPrivate::setTopLevelScreen(QScreen*, bool) ( QScreen(0xfe3480) ): Attempt to set a screen on a child window.
0x1a23560 void QWindowPrivate::setTopLevelScreen(QScreen*, bool) ( QScreen(0xfe3480) ): Attempt to set a screen on a child window.
0x1a2e9f0 void QWindowPrivate::setTopLevelScreen(QScreen*, bool) ( QScreen(0xfe3480) ): Attempt to set a screen on a child window.
[WARN] [1583095895.473658, 2216.849000]: Controller Spawner couldn't find the expected controller_manager ROS interface.
Gazebo.launch：
<launch>
<include file="$(find gazebo_ros)/launch/empty_world.launch">
<arg name="verbose" value="true" />
</include>
<node
name="tf_footprint_base"
pkg="tf"
type="static_transform_publisher"
args="0 0 0 0 0 0 base_link base_footprint 40" />
<!-- ******************** Robot Model ******************** -->
<param name="robot_description" command="$(find xacro)/xacro --inorder '$(find robot)/urdf/robot.urdf'"/>
<node
name="spawn_model"
pkg="gazebo_ros"
type="spawn_model"
args="-file $(find robot)/urdf/robot.urdf -urdf -model robot"
output="screen" />
<node
name="fake_joint_calibration"
pkg="rostopic"
type="rostopic"
args="pub /calibrated std_msgs/Bool true" />
</launch>
RViz.launch：
<launch>
<arg
name="model" />
<arg
name="gui"
default="False" />
<param
name="robot_description"
textfile="$(find robot)/urdf/robot.urdf" />
<param
name="use_gui"
value="$(arg gui)" />
<node
name="joint_state_publisher"
pkg="joint_state_publisher"
type="joint_state_publisher" />
<node
name="robot_state_publisher"
pkg="robot_state_publisher"
type="state_publisher" />
<node
name="rviz"
pkg="rviz"
type="rviz"
args="-d $(find robot)/urdf.rviz" />
</launch>
robot_control.launch：
<launch>
<!-- Get description of robot-->
<param name = 'robot_description' command="cat $(find robot)/urdf/robot.urdf" />
<!-- Send fake joint values -->
<node name="joint_state_publisher" pkg="joint_state_publisher" type="joint_state_publisher">
<param name="use_gui" value="FALSE"/>
</node>
<!-- Show in Rviz-->
<node name="rviz" pkg="rviz" type="rviz" args="-d $(find robot)/urdf.rviz"/>
<!-- Load joint controller configurations from YAML file to parameter server -->
<rosparam file="$(find robot)/config/robot_control.yaml" command="load"/>
<!-- convert joint states to TF transforms for rviz, etc -->
<node name="robot_state_publisher" pkg="robot_state_publisher" type="robot_state_publisher"
respawn="false" output="screen" ns="/robot">
<remap from="/joint_states" to="/robot/joint_states" />
</node>
<!-- load the controllers -->
<node name="controller_spawner" pkg="controller_manager" type="spawner" respawn="false"
output="screen" ns="/robot" args="joint_state_controller FRJ_velocity_controller FLJ_velocity_controller BRJ_velocity_controller BLJ_velocity_controller FLJ_position_controller FRJ_position_controller BLJ_position_controller BRJ_position_controller "/>
</launch>
URDF文件：
<?xml version="1.0" ?>
<!-- =================================================================================== -->
<!-- | This document was autogenerated by xacro from robot.xacro | -->
<!-- | EDITING THIS FILE BY HAND IS NOT RECOMMENDED | -->
<!-- =================================================================================== -->
<robot name="robot" xmlns:xacro="http://www.ros.org/wiki/xacro">
<!--This URDF was automatically created by SolidWorks to URDF Exporter! Originally created by Stephen Brawner (brawner@gmail.com)
Commit Version: 1.5.1-0-g916b5db Build Version: 1.5.7152.31018
For more information, please see http://wiki.ros.org/sw_urdf_exporter -->
<link name="base_link">
<inertial>
<origin rpy="0 0 0" xyz="0.00390777224516517 -0.032446267219719 0.184169550820421"/>
<mass value="4.20121630268732"/>
<inertia ixx="0.0149000386129946" ixy="-4.66831001352174E-09" ixz="5.23920338795194E-08" iyy="0.0234359493013497" iyz="0.000771538751024883" izz="0.0286744535302635"/>
</inertial>
<visual>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<mesh filename="package://robot/meshes/base_link.STL"/>
</geometry>
<material name="">
<color rgba="0.529411764705882 0.549019607843137 0.549019607843137 1"/>
</material>
</visual>
<collision>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<mesh filename="package://robot/meshes/base_link.STL"/>
</geometry>
</collision>
</link>
<link name="FL">
<inertial>
<origin rpy="0 0 0" xyz="-5.55111512312578E-17 9.10729824887824E-18 -6.93889390390723E-18"/>
<mass value="0.0615219544751675"/>
<inertia ixx="5.54433425808419E-05" ixy="-1.45453466603006E-20" ixz="-1.00225538664655E-21" iyy="3.00921775305435E-05" iyz="2.309188417276E-21" izz="3.00921775305435E-05"/>
</inertial>
<visual>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<mesh filename="package://robot/meshes/FL.STL"/>
</geometry>
<material name="">
<color rgba="0.298039215686275 0.298039215686275 0.298039215686275 1"/>
</material>
</visual>
<collision>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<mesh filename="package://robot/meshes/FL.STL"/>
</geometry>
</collision>
</link>
<joint name="FLJ" type="continuous">
<origin rpy="1.5707963267949 0 0" xyz="-0.162088045105054 0.0440194465480433 -0.0035605397876617"/>
<parent link="base_link"/>
<child link="FL"/>
<axis xyz="-1 0 0"/>
</joint>
<link name="FR">
<inertial>
<origin rpy="0 0 0" xyz="2.77555756156289E-17 -5.3776427755281E-17 3.46944695195361E-17"/>
<mass value="0.0615219544751675"/>
<inertia ixx="5.54433425808419E-05" ixy="-1.73616162087809E-20" ixz="-8.97406720914896E-21" iyy="3.00921775305435E-05" iyz="-2.24902265994014E-21" izz="3.00921775305435E-05"/>
</inertial>
<visual>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<mesh filename="package://robot/meshes/FR.STL"/>
</geometry>
<material name="">
<color rgba="0.298039215686275 0.298039215686275 0.298039215686275 1"/>
</material>
</visual>
<collision>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<mesh filename="package://robot/meshes/FR.STL"/>
</geometry>
</collision>
</link>
<joint name="FRJ" type="continuous">
<origin rpy="1.5707963267949 0 0" xyz="0.169947769597777 0.0440194465480434 -0.00356053978766185"/>
<parent link="base_link"/>
<child link="FR"/>
<axis xyz="-1 0 0"/>
</joint>
<link name="BL">
<inertial>
<origin rpy="0 0 0" xyz="-5.55111512312578E-17 7.85396053748499E-16 -1.38777878078145E-17"/>
<mass value="0.0615219544751675"/>
<inertia ixx="5.54433425808419E-05" ixy="-5.54431358512462E-21" ixz="2.27097066282367E-22" iyy="3.00921775305435E-05" iyz="2.73146067339844E-21" izz="3.00921775305435E-05"/>
</inertial>
<visual>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<mesh filename="package://robot/meshes/BL.STL"/>
</geometry>
<material name="">
<color rgba="0.298039215686275 0.298039215686275 0.298039215686275 1"/>
</material>
</visual>
<collision>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<mesh filename="package://robot/meshes/BL.STL"/>
</geometry>
</collision>
</link>
<joint name="BLJ" type="continuous">
<origin rpy="1.5707963267949 0 0" xyz="-0.162088045105054 -0.0759805534519569 -0.00356053978766179"/>
<parent link="base_link"/>
<child link="BL"/>
<axis xyz="-1 0 0"/>
</joint>
<link name="BR">
<inertial>
<origin rpy="0 0 0" xyz="-8.32667268468867E-17 7.03430369508595E-16 2.77555756156289E-17"/>
<mass value="0.0615219544751675"/>
<inertia ixx="5.54433425808419E-05" ixy="-7.26178700863739E-21" ixz="-6.24920580783796E-21" iyy="3.00921775305435E-05" iyz="-3.51228039755728E-21" izz="3.00921775305435E-05"/>
</inertial>
<visual>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<mesh filename="package://robot/meshes/BR.STL"/>
</geometry>
<material name="">
<color rgba="0.298039215686275 0.298039215686275 0.298039215686275 1"/>
</material>
</visual>
<collision>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<mesh filename="package://robot/meshes/BR.STL"/>
</geometry>
</collision>
</link>
<joint name="BRJ" type="continuous">
<origin rpy="1.5708 0 0" xyz="0.16991 -0.075981 -0.0035605"/>
<parent link="base_link"/>
<child link="BR"/>
<axis xyz="-1 0 0"/>
</joint>
<link name="TB">
<inertial>
<origin rpy="0 0 0" xyz="-7.8063E-18 1.3878E-17 0.001"/>
<mass value="0.36807"/>
<inertia ixx="0.00019523" ixy="7.0972E-20" ixz="-4.0656E-22" iyy="0.0026688" iyz="4.5169E-23" izz="0.0028638"/>
</inertial>
<visual>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<mesh filename="package://robot/meshes/TB.STL"/>
</geometry>
<material name="">
<color rgba="0.52941 0.54902 0.54902 1"/>
</material>
</visual>
<collision>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<mesh filename="package://robot/meshes/TB.STL"/>
</geometry>
</collision>
</link>
<joint name="TBJ" type="fixed">
<origin rpy="0 0 0" xyz="0.003912 -0.086602 0.46844"/>
<parent link="base_link"/>
<child link="TB"/>
<axis xyz="0 0 0"/>
</joint>
<!-- LIDAR -->
<gazebo reference="hokuyo_link">
<sensor name="head_hokuyo_sensor" type="ray">
<pose> 0 0 0 0 0 0 </pose>
<visualize>true</visualize>
<update_rate>40</update_rate>
<ray>
<scan>
<horizontal>
<samples>720</samples>
<resolution>1</resolution>
<min_angle>-1.57079</min_angle>
<max_angle>1.57079</max_angle>
</horizontal>
</scan>
<range>
<min>0.1</min>
<max>30</max>
<resolution>0.1</resolution>
</range>
</ray>
<plugin filename="libgazebo_ros_laser.so" name="gazebo_ros_head_hokuyo_controller">
<topicName>/scan</topicName>
<frameName>hokuyo_link</frameName>
</plugin>
</sensor>
</gazebo>
<joint name="TB_Lidar" type="fixed">
<axis xyz="0 1 0"/>
<parent link="TB"/>
<child link="hokuyo_link"/>
<origin rpy="0 0 1.57079633" xyz="0 0 0.005"/>
</joint>
<!-- Hokuyo Laser -->
<link name="hokuyo_link">
<collision>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<box size="0.01 0.01 0.01"/>
</geometry>
</collision>
</link>
<!-- Gazebo Ros Control Plugin -->
<gazebo>
<plugin filename="libgazebo_ros_control.so" name="gazebo_ros_control">
<robotNamespace>/robot</robotNamespace>
<robotSimType>gazebo_ros_control/DefaultRobotHWSim</robotSimType>
<legacyModeNS>true</legacyModeNS>
</plugin>
</gazebo>
<!-- Gazebo Transmission -->
<transmission name="FLT">
<type>transmission_interface/SimpleTransmission</type>
<actuator name="motor1">
<mechanicalReduction>1</mechanicalReduction>
</actuator>
<joint name="FLJ">
<hardwareInterface>hardware_interface/EffortJointInterface</hardwareInterface>
</joint>
</transmission>
<transmission name="FRT">
<type>transmission_interface/SimpleTransmission</type>
<actuator name="motor2">
<mechanicalReduction>1</mechanicalReduction>
</actuator>
<joint name="FRJ">
<hardwareInterface>hardware_interface/EffortJointInterface</hardwareInterface>
</joint>
</transmission>
<transmission name="BLT">
<type>transmission_interface/SimpleTransmission</type>
<actuator name="motor3">
<mechanicalReduction>1</mechanicalReduction>
</actuator>
<joint name="BLJ">
<hardwareInterface>hardware_interface/EffortJointInterface</hardwareInterface>
</joint>
</transmission>
<transmission name="BRT">
<type>transmission_interface/SimpleTransmission</type>
<actuator name="motor4">
<mechanicalReduction>1</mechanicalReduction>
</actuator>
<joint name="BRJ">
<hardwareInterface>hardware_interface/EffortJointInterface</hardwareInterface>
</joint>
</transmission>
<!-- Differential Drive -->
<gazebo>
<plugin filename="libgazebo_ros_diff_drive.so" name="differential_drive_controller">
<leftJoint>FLJ</leftJoint>
<legacyMode>false</legacyMode>
<rightJoint>FRJ</rightJoint>
<robotBaseFrame>base_link</robotBaseFrame>
<wheelSeperation>0.25</wheelSeperation>
<wheelDiameter>0.07</wheelDiameter>
<publishWheelJointState>true</publishWheelJointState>
</plugin>
</gazebo>
</robot>
$ rostopic列表
/calibrated
/clicked_point
/clock
/gazebo/link_states
/gazebo/model_states
/gazebo/parameter_descriptions
/gazebo/parameter_updates
/gazebo/set_link_state
/gazebo/set_model_state
/gazebo_gui/parameter_descriptions
/gazebo_gui/parameter_updates
/initialpose
/joint_states
/move_base_simple/goal
/robot/joint_states
/rosout
/rosout_agg
/scan
/tf
/tf_static
我可以在RViz和Gazebo中正确地看到我的模型，但是由于不存在主题，所以无法在轮子上发出任何命令。
答案 0 :(得分：0)
好，所以问题似乎出在以下几节中：
<link name="dummy"></link>
和作为父级连接到基本链接的虚拟关节：
<joint name="dummy_joint" type="fixed">
<parent link="dummy"/>
<child link="base_link"/>
</joint>
在URDF中，我也不得不注释掉Differential_Drive部分，因为一旦定义了传动部分，就不需要它了。 在robot_control.yaml中，我不得不注释掉Velocity控制器，因为位置控制器足以为机器人提供控制。