标签:topic size publish combine ras 技术 sim class 创建
要建立自己的自主机器人,首先,必须要建立自己的机器人模型,
URDF
(Unified Robot Description Format
)模型。
机器人URDF模型主要由两个文件组成:.xacro 是主文件,包含URDF项,包括关节,连杆;.gazebo包含gazebo的具体信息以便在gazebo中仿真。
例子请见:How to Build a Differential Drive Simulation
以下工程的源码下载地址请见:
http://download.csdn.net/download/ziqian0512/9816156
使用方法主要包括以下三个部分:
rviz查看机器人
roslaunch neurobot_description neurobot_rviz.launch
gazebo 仿真
groslaunch neurobot_gazebo neurobot_world.launch
控制机器人运动
rostopic pub /cmd_vel geometry_msgs/Twist "linear:
x: 0.1
y: 0.0
z: 0.0
angular:
x: 0.0
y: 0.0
z: 0.0"
如何一步步设计自己的工程请见以下部分的详细说明:
catkin_create_pkg neurobot_description
neurobot_description/urdf/
├── macros.xacro 帮助简化的宏
├── materials.xacro 材料说明
├── neurobot.gazebo gazebo具体信息
└── neurobot.xacro URDF 主文件
在neurobot.xacro
中添加chassis, wheels,
<link name=‘chassis‘> <pose>0 0 0.1 0 0 0</pose> <inertial> <mass value="15.0"/> <origin xyz="0.0 0 0.1" rpy=" 0 0 0"/> <inertia ixx="0.1" ixy="0" ixz="0" iyy="0.1" iyz="0" izz="0.1" /> </inertial> <collision name=‘collision‘> <geometry> <box size=".4 .2 .1"/> </geometry> </collision> <visual name=‘chassis_visual‘> <origin xyz="0 0 0" rpy=" 0 0 0"/> <geometry> <box size=".4 .2 .1"/> </geometry> </visual> <collision name=‘caster_collision‘> <origin xyz="-0.15 0 -0.05" rpy=" 0 0 0"/> <geometry> <sphere radius="0.05"/> </geometry> <surface> <friction> <ode> <mu>0</mu> <mu2>0</mu2> <slip1>1.0</slip1> <slip2>1.0</slip2> </ode> </friction> </surface> </collision> <visual name=‘caster_visual‘> <origin xyz="-0.15 0 -0.05" rpy=" 0 0 0"/> <geometry> <sphere radius="0.05"/> </geometry> </visual> <collision name=‘caster_front_collision‘> <origin xyz="0.15 0 -0.05" rpy=" 0 0 0"/> <geometry> <sphere radius="0.05"/> </geometry> <surface> <friction> <ode> <mu>0</mu> <mu2>0</mu2> <slip1>1.0</slip1> <slip2>1.0</slip2> </ode> </friction> </surface> </collision> <visual name=‘caster_front_visual‘> <origin xyz="0.15 0 -0.05" rpy=" 0 0 0"/> <geometry> <sphere radius="0.05"/> </geometry> </visual> </link>
<link name="left_wheel"> <!--origin xyz="0.1 0.13 0.1" rpy="0 1.5707 1.5707"/--> <collision name="collision"> <origin xyz="0 0 0" rpy="0 1.5707 1.5707"/> <geometry> <cylinder radius="0.1" length="0.05"/> </geometry> </collision> <visual name="left_wheel_visual"> <origin xyz="0 0 0" rpy="0 1.5707 1.5707"/> <geometry> <cylinder radius="0.1" length="0.05"/> </geometry> </visual> <inertial> <origin xyz="0 0 0" rpy="0 1.5707 1.5707"/> <mass value="5"/> <inertia ixx=".1" ixy="0.0" ixz="0.0" iyy=".1" iyz="0.0" izz=".1"/> </inertial> </link>
<joint type="continuous" name="left_wheel_hinge"> <origin xyz="0 0.15 0" rpy="0 0 0"/> <!--origin xyz="0.1 0.13 0" rpy="0 1.5707 1.5707"/--> <child link="left_wheel"/> <parent link="chassis"/> <axis xyz="0 1 0" rpy="0 0 0"/> <limit effort="10000" velocity="1000"/> <joint_properties damping="1.0" friction="1.0"/> </joint> <joint type="continuous" name="right_wheel_hinge"> <origin xyz="0 -0.15 0" rpy="0 0 0"/> <!--origin xyz="0.1 -0.13 0" rpy="0 1.5707 1.5707"/--> <child link="right_wheel"/> <parent link="chassis"/> <axis xyz="0 1 0" rpy="0 0 0"/> <limit effort="10000" velocity="1000"/> <joint_properties damping="1.0" friction="1.0"/> </joint>
要实现自主导航还需要添加camera和laser,有了激光器和摄像头我们才能让机器人去感知外部世界。
<link name="camera"> <collision> <origin xyz="0 0 0" rpy="0 0 0"/> <geometry> <box size="${cameraSize} ${cameraSize} ${cameraSize}"/> </geometry> </collision> <visual> <origin xyz="0 0 0" rpy="0 0 0"/> <geometry> <box size="${cameraSize} ${cameraSize} ${cameraSize}"/> </geometry> <material name="green"/> </visual> <inertial> <mass value="${cameraMass}" /> <origin xyz="0 0 0" rpy="0 0 0"/> <box_inertia m="${cameraMass}" x="${cameraSize}" y="${cameraSize}" z="${cameraSize}" /> <inertia ixx="1e-6" ixy="0" ixz="0" iyy="1e-6" iyz="0" izz="1e-6" /> </inertial> </link> <joint name="camera_joint" type="fixed"> <axis xyz="0 1 0" /> <origin xyz=".2 0 0" rpy="0 0 0"/> <parent link="chassis"/> <child link="camera"/> </joint>
<joint name="hokuyo_joint" type="fixed"> <axis xyz="0 1 0" /> <origin xyz=".15 0 .1" rpy="0 0 0"/> <parent link="chassis"/> <child link="hokuyo"/> </joint> <!-- Hokuyo Laser --> <link name="hokuyo"> <collision> <origin xyz="0 0 0" rpy="0 0 0"/> <geometry> <box size="0.1 0.1 0.1"/> </geometry> </collision> <visual> <origin xyz="0 0 0" rpy="0 0 0"/> <geometry> <mesh filename="package://neurobot_description/meshes/hokuyo.dae"/> </geometry> </visual> <inertial> <mass value="1e-5" /> <origin xyz="0 0 0" rpy="0 0 0"/> <inertia ixx="1e-6" ixy="0" ixz="0" iyy="1e-6" iyz="0" izz="1e-6" /> </inertial> </link>
只有添加了模型插件,我们才能编写代码控制机器人的运动,采用信息。插件是模型和代码的桥梁。
在neurobot.gazebo
中添加gazebo具体描述信息和插件。
<joint name="hokuyo_joint" type="fixed"> <axis xyz="0 1 0" /> <origin xyz=".15 0 .1" rpy="0 0 0"/> <parent link="chassis"/> <child link="hokuyo"/> </joint> <!-- Hokuyo Laser --> <link name="hokuyo"> <collision> <origin xyz="0 0 0" rpy="0 0 0"/> <geometry> <box size="0.1 0.1 0.1"/> </geometry> </collision> <visual> <origin xyz="0 0 0" rpy="0 0 0"/> <geometry> <mesh filename="package://neurobot_description/meshes/hokuyo.dae"/> </geometry> </visual> <inertial> <mass value="1e-5" /> <origin xyz="0 0 0" rpy="0 0 0"/> <inertia ixx="1e-6" ixy="0" ixz="0" iyy="1e-6" iyz="0" izz="1e-6" /> </inertial> </link>
<gazebo reference="camera"> <material>Gazebo/Green</material> <sensor type="camera" name="camera1"> <update_rate>30.0</update_rate> <camera name="head"> <horizontal_fov>1.3962634</horizontal_fov> <image> <width>800</width> <height>800</height> <format>R8G8B8</format> </image> <clip> <near>0.02</near> <far>300</far> </clip> </camera> <plugin name="camera_controller" filename="libgazebo_ros_camera.so"> <alwaysOn>true</alwaysOn> <updateRate>0.0</updateRate> <cameraName>neurobot/camera1</cameraName> <imageTopicName>image_raw</imageTopicName> <cameraInfoTopicName>camera_info</cameraInfoTopicName> <frameName>camera</frameName> <hackBaseline>0.07</hackBaseline> <distortionK1>0.0</distortionK1> <distortionK2>0.0</distortionK2> <distortionK3>0.0</distortionK3> <distortionT1>0.0</distortionT1> <distortionT2>0.0</distortionT2> </plugin> </sensor> </gazebo>
laser的几何信息采用mesh文件hokuyo.dae放在meshes文件夹中,
<!-- hokuyo --> <gazebo reference="hokuyo"> <sensor type="gpu_ray" name="head_hokuyo_sensor"> <pose>0 0 0 0 0 0</pose> <visualize>false</visualize> <update_rate>40</update_rate> <ray> <scan> <horizontal> <samples>720</samples> <resolution>1</resolution> <min_angle>-1.570796</min_angle> <max_angle>1.570796</max_angle> </horizontal> </scan> <range> <min>0.10</min> <max>30.0</max> <resolution>0.01</resolution> </range> <noise> <type>gaussian</type> <!-- Noise parameters based on published spec for Hokuyo laser achieving "+-30mm" accuracy at range < 10m. A mean of 0.0m and stddev of 0.01m will put 99.7% of samples within 0.03m of the true reading. --> <mean>0.0</mean> <stddev>0.01</stddev> </noise> </ray> <plugin name="gazebo_ros_head_hokuyo_controller" filename="libgazebo_ros_gpu_laser.so"> <topicName>/neurobot/laser/scan</topicName> <frameName>hokuyo</frameName> </plugin> </sensor> </gazebo>
<gazebo reference="chassis"> <material>Gazebo/Orange</material> </gazebo> <gazebo reference="left_wheel"> <material>Gazebo/Blue</material> </gazebo> <gazebo reference="right_wheel"> <material>Gazebo/Blue</material> </gazebo>
终于到了我们可以控制自己建立的机器人了。
roslaunch neurobot_description neurobot_rviz.launch
neurobot_rviz.launch 文件如下
<?xml version="1.0"?> <launch> <param name="robot_description" command="$(find xacro)/xacro.py ‘$(find mybot_description)/urdf/mybot.xacro‘"/> <!-- send fake joint values --> <node name="joint_state_publisher" pkg="joint_state_publisher" type="joint_state_publisher"> <param name="use_gui" value="False"/> </node> <!-- Combine joint values --> <node name="robot_state_publisher" pkg="robot_state_publisher" type="state_publisher"/> <!-- Show in Rviz --> <node name="rviz" pkg="rviz" type="rviz"/> <!--node name="rviz" pkg="rviz" type="rviz" args="-d $(find mybot_description)/launch/myrobot.rviz"/--> </launch>
依然采用在turtlebot中使用的world场景,加载机器人。
roslaunch neurobot_gazebo neurobot_world.launch
通过如下命令
rostopic list
我们可以找到非常重要的四个topic
/cmd_vel 速度控制命令
/neurobot/camera1/image_raw 图像信息
/neurobot/laser/scan 激光数据
/odom 里程计
使用如下命令便可以控制机器人运动了,fancy。
rostopic pub /cmd_vel geometry_msgs/Twist "linear:
x: 0.1
y: 0.0
z: 0.0
angular:
x: 0.0
y: 0.0
z: 0.0"
也可以使用我们之前turtlebot中使用的keyboard_teleop.launch
和keyop.launch
, 将topic主题映射到/cmd_vel
。
How to Build a Differential Drive Simulation
在ROS中开始自主机器人仿真 - 4 建立自己的自主机器人URDF模型
标签:topic size publish combine ras 技术 sim class 创建
原文地址:http://www.cnblogs.com/taiping/p/6721264.html