开发笔记:《ROS理论与实践》学习笔记URDF机器人建模

在学习《ROS理论与实践》课程时&＃xff0c;记录了学习过程中的编程练习&＃xff0c;课后作业以及发现的问题&＃xff0c;后续会对尚未解决的问题继续分析并更新&＃xff0c;纯小白&＃xff0c;仅供参考。
本次学习笔记关于课程中的第五讲&＃xff1a;URDF机器人建模 。主要学习了ROS的URDF建模方法。

1.URDF建模方法

1. 
   描述机器人某个刚体部分的外观和物理属性
2. 
   描述两个link之间的关系&＃xff0c;包括关节运动的位置和速度限制

3. 
   机器人模型顶层标签

   <robot name&＃61;"xxx">
<link> ... link>
<link> ... link>
<joint> ... joint>
<joint> ... joint>
robot>


2.机器人建模功能包创建

$ catkin_create_pkg mybot_description urdf xacro


3.检查urdf模型结构

$ urdf_to_graphiz mybot_base.urdf


创建一个自己的机器人模型

urdf模型文件如下&＃xff1a;


<robot name&＃61;"mybot">
<link name&＃61;"base_link">
<visual>
<origin xyz&＃61;" 0 0 0" rpy&＃61;"0 0 0" />
<geometry>
<cylinder length&＃61;"0.05" radius&＃61;"0.20"/>
geometry>
<material name&＃61;"yellow">
<color rgba&＃61;"1 0.4 0 1"/>
material>
visual>
link>
<joint name&＃61;"left_motor_joint" type&＃61;"fixed">
<origin xyz&＃61;"-0.1 0.11 0" rpy&＃61;"0 0 0"/>
<parent link&＃61;"base_link"/>
<child link&＃61;"left_motor_link"/>
<axis xyz&＃61;"0 1 0"/>
joint>
<link name&＃61;"left_motor_link">
<visual>
<origin xyz&＃61;"0 0 0" rpy&＃61;"1.5707 0 0" />
<geometry>

geometry>
<material name&＃61;"white">
<color rgba&＃61;"1 1 1 0.9"/>
material>
visual>
link>
<joint name&＃61;"left_wheel_joint" type&＃61;"continuous">
<origin xyz&＃61;"0 0.1025 0" rpy&＃61;"0 0 0"/>
<parent link&＃61;"left_motor_link"/>
<child link&＃61;"left_wheel_link"/>
<axis xyz&＃61;"0 1 0"/>
joint>
<link name&＃61;"left_wheel_link">
<visual>
<origin xyz&＃61;"0 0 0" rpy&＃61;"1.5707 0 0" />
<geometry>

geometry>
<material name&＃61;"white">
<color rgba&＃61;"1 1 1 0.9"/>
material>
visual>
link>
<joint name&＃61;"right_motor_joint" type&＃61;"fixed">
<origin xyz&＃61;"-0.1 -0.11 0" rpy&＃61;"0 0 0"/>
<parent link&＃61;"base_link"/>
<child link&＃61;"right_motor_link"/>
<axis xyz&＃61;"0 1 0"/>
joint>
<link name&＃61;"right_motor_link">
<visual>
<origin xyz&＃61;"0 0 0" rpy&＃61;"1.5707 0 0" />
<geometry>

geometry>
<material name&＃61;"white">
<color rgba&＃61;"1 1 1 0.9"/>
material>
visual>
link>
<joint name&＃61;"right_wheel_joint" type&＃61;"continuous">
<origin xyz&＃61;"0 -0.1025 0" rpy&＃61;"0 0 0"/>
<parent link&＃61;"right_motor_link"/>
<child link&＃61;"right_wheel_link"/>
<axis xyz&＃61;"0 1 0"/>
joint>
<link name&＃61;"right_wheel_link">
<visual>
<origin xyz&＃61;"0 0 0" rpy&＃61;"1.5707 0 0" />
<geometry>

geometry>
<material name&＃61;"white">
<color rgba&＃61;"1 1 1 0.9"/>
material>
visual>
link>
<joint name&＃61;"front_caster_joint" type&＃61;"continuous">
<origin xyz&＃61;"0.18 0 -0.025" rpy&＃61;"0 0 0"/>
<parent link&＃61;"base_link"/>
<child link&＃61;"front_caster_link"/>
<axis xyz&＃61;"0 1 0"/>
joint>
<link name&＃61;"front_caster_link">
<visual>
<origin xyz&＃61;"0 0 -0.025" rpy&＃61;"1.5707 0 0"/>
<geometry>

geometry>
<material name&＃61;"black">
<color rgba&＃61;"0 0 0 0.95"/>
material>
visual>
link>
<link name&＃61;"camera_link">
<visual>
<origin xyz&＃61;" 0 0 0 " rpy&＃61;"0 0 0" />
<geometry>
<box size&＃61;"0.03 0.04 0.04" />
geometry>
<material name&＃61;"black">
<color rgba&＃61;"0 0 0 0.95"/>
material>
visual>
link>
<joint name&＃61;"camera_joint" type&＃61;"fixed">
<origin xyz&＃61;"0.17 0 0.025" rpy&＃61;"0 0 0"/>
<parent link&＃61;"base_link"/>
<child link&＃61;"camera_link"/>
joint>
<link name&＃61;"kinect_link">
<visual>
<origin xyz&＃61;"0 0 0" rpy&＃61;"0 0 1.5708"/>
<geometry>
<mesh filename&＃61;"package://mybot_description/meshes/kinect.dae" />
geometry>
visual>
link>
<joint name&＃61;"kinect_joint" type&＃61;"fixed">
<origin xyz&＃61;"0.11 0 0.06" rpy&＃61;"0 0 0"/>
<parent link&＃61;"base_link"/>
<child link&＃61;"kinect_link"/>
joint>
robot>


launch文件代码如下&＃xff1a;

<launch>
<param name&＃61;"robot_description" textfile&＃61;"$(find mybot_description)/urdf/mybot_all.urdf" />

<param name&＃61;"use_gui" value&＃61;"true"/>


<node name&＃61;"joint_state_publisher" pkg&＃61;"joint_state_publisher" type&＃61;"joint_state_publisher" />


<node name&＃61;"robot_state_publisher" pkg&＃61;"robot_state_publisher" type&＃61;"state_publisher" />


<node name&＃61;"rviz" pkg&＃61;"rviz" type&＃61;"rviz" args&＃61;"-d $(find mybot_description)/config/mybot_urdf.rviz" required&＃61;"true" />
launch>


运行效果&＃xff1a;

$ roslaunch mybot_description display_mybot_all_urdf.launch


本讲主要学习了urdf的建模方法&＃xff0c;并完成了自己的机器人模型的建模。