学习的内容：
（1）创建HDL-32传感器的SDF文件模型
（2）将创建的模型应用到gazebo的模型库
（3）实现模型的显示和输出
（4）使用插件控制模型
（5）在gazebo和RViz中可视化模型
《一》模型的创建
模型：
（1）a base cylinder and top cylinder, where the top cylinder spins, and
（2）a set of laser rays oriented in the vertical fan.
step 1：创建world文件
选择一个文件夹，打开终端输入：gedit velodyne.world
在文件中输入以下内容：
<?xml version="1.0" ?>
<sdf version="1.5">
<world name="default">
<!-- A global light source -->
<include>
<uri>model://sun</uri>
</include>
<!-- A ground plane -->
<include>
<uri>model://ground_plane</uri>
</include>
</world>
</sdf>
world文件的主要内容是设置地面和灯光。
step2：在world文件的标签前加入以下内容：
<model name="velodyne_hdl-32">
<!-- Give the base link a unique name -->
<link name="base">
<!-- Offset the base by half the lenght of the cylinder -->
<pose>0 0 0.029335 0 0 0</pose>
<collision name="base_collision">
<geometry>
<cylinder>
<!-- Radius and length provided by Velodyne -->
<radius>.04267</radius>
<length>.05867</length>
</cylinder>
</geometry>
</collision>
<!-- The visual is mostly a copy of the collision -->
<visual name="base_visual">
<geometry>
<cylinder>
<radius>.04267</radius>
<length>.05867</length>
</cylinder>
</geometry>
</visual>
</link>
<!-- Give the base link a unique name -->
<link name="top">
<!-- Vertically offset the top cylinder by the length of the bottom
cylinder and half the length of this cylinder. -->
<pose>0 0 0.095455 0 0 0</pose>
<collision name="top_collision">
<geometry>
<cylinder>
<!-- Radius and length provided by Velodyne -->
<radius>0.04267</radius>
<length>0.07357</length>
</cylinder>
</geometry>
</collision>
<!-- The visual is mostly a copy of the collision -->
<visual name="top_visual">
<geometry>
<cylinder>
<radius>0.04267</radius>
<length>0.07357</length>
</cylinder>
</geometry>
</visual>
</link>
</model>
step3：利用gazebo velodyne.world -u 看暂停仿真下的模型。
step4：在模型上加入惯性单元，实现对外力作用下的反应
<model name="velodyne_hdl-32">
<link name="base">
<pose>0 0 0.029335 0 0 0</pose>
<inertial>
<mass>1.2</mass>
<inertia>
<ixx>0.001087473</ixx>
<iyy>0.001087473</iyy>
<izz>0.001092437</izz>
<ixy>0</ixy>
<ixz>0</ixz>
<iyz>0</iyz>
</inertia>
</inertial>
<link name="top">
<pose>0 0 0.095455 0 0 0</pose>
<inertial>
<mass>0.1</mass>
<inertia>
<ixx>0.000090623</ixx>
<iyy>0.000090623</iyy>
<izz>0.000091036</izz>
<ixy>0</ixy>
<ixz>0</ixz>
<iyz>0</iyz>
</inertia>
</inertial>
step5：加入关节，在的前面加入以下内容：
<!-- Each joint must have a unique name -->
<joint type="revolute" name="joint">
<!-- Position the joint at the bottom of the top link -->
<pose>0 0 -0.036785 0 0 0</pose>
<!-- Use the base link as the parent of the joint -->
<parent>base</parent>
<!-- Use the top link as the child of the joint -->
<child>top</child>
<!-- The axis defines the joint's degree of freedom -->
<axis>
<!-- Revolve around the z-axis -->
<xyz>0 0 1</xyz>
<!-- Limit refers to the range of motion of the joint -->
<limit>
<!-- Use a very large number to indicate a continuous revolution -->
<lower>-10000000000000000</lower>
<upper>10000000000000000</upper>
</limit>
</axis>
</joint>
step6：加入传感器，在这个模块中加入以下内容：；
<!-- Add a ray sensor, and give it a name -->
<sensor type="ray" name="sensor">
<!-- Position the ray sensor based on the specification. Also rotate
it by 90 degrees around the X-axis so that the <horizontal> rays
become vertical -->
<pose>0 0 -0.004645 1.5707 0 0</pose>
<!-- Enable visualization to see the rays in the GUI -->
<visualize>true</visualize>
<!-- Set the update rate of the sensor -->
<update_rate>30</update_rate>
</sensor>
step7：定义ray的scan和rage，在sensor模块中的update_rate后面加入以下内容：
<ray>
<!-- The scan element contains the horizontal and vertical beams.
We are leaving out the vertical beams for this tutorial. -->
<scan>
<!-- The horizontal beams -->
<horizontal>
<!-- The velodyne has 32 beams(samples) -->
<samples>32</samples>
<!-- Resolution is multiplied by samples to determine number of
simulated beams vs interpolated beams. See:
http://sdformat/spec?ver=1.6&elem=sensor#horizontal_resolution
-->
<resolution>1</resolution>
<!-- Minimum angle in radians -->
<min_angle>-0.53529248</min_angle>
<!-- Maximum angle in radians -->
<max_angle>0.18622663</max_angle>
</horizontal>
</scan>
<!-- Range defines characteristics of an individual beam -->
<range>
<!-- Minimum distance of the beam -->
<min>0.05</min>
<!-- Maximum distance of the beam -->
<max>70</max>
<!-- Linear resolution of the beam -->
<resolution>0.02</resolution>
</range>
</ray>
仿真效果：
gazebo velodyne.world -u
点击开始仿真：
全部的模型代码：
<?xml version="1.0" ?>
<sdf version="1.5">
<world name="default">
<!-- A global light source -->
<include>
<uri>model://sun</uri>
</include>
<!-- A ground plane -->
<include>
<uri>model://ground_plane</uri>
</include>
<model name="velodyne_hdl-32">
<!-- Give the base link a unique name -->
<link name="base">
<!-- Offset the base by half the lenght of the cylinder -->
<pose>0 0 0.029335 0 0 0</pose>
<inertial>
<mass>1.2</mass>
<inertia>
<ixx>0.001087473</ixx>
<iyy>0.001087473</iyy>
<izz>0.001092437</izz>
<ixy>0</ixy>
<ixz>0</ixz>
<iyz>0</iyz>
</inertia>
</inertial>
<collision name="base_collision">
<geometry>
<cylinder>
<!-- Radius and length provide by Velodyne -->
<radius>.04267</radius>
<length>.05867</length>
</cylinder>
</geometry>
</collision>
<!-- The visual is mostly a copy of the collision -->
<visual name="base_visual">
<geometry>
<cylinder>
<radius>.04267</radius>
<length>.05867</length>
</cylinder>
</geometry>
</visual>
</link>
<link name="top">
<!--Add a ray sensor,and give it a name -->
<sensor type="ray" name="sensor">
<!-- Position the ray sensor based on the specifucation Also rotate it by 90 degrees around the x-axis so that the <horizontal> rays become wertical -->
<pose>0 0 -0.004645 1.5707 0 0</pose>
<!-- Enable visualization to see the rays in the GUI-->
<visualize>true</visualize>
<!--Set the update rate of the sensor-->
<update_rate>30</update_rate>
<ray>
<!-- The scan element contains the horizontal and vertiral beams. We are leaving out the vertical beams for this tutorial.-->
<scan>
<!--The horizontal beams-->
<horizontal>
<!--The velodyne has 32 beams(samples)-->
<samples>32</samples>
<!--Resolution is multiplited by sample to detemine number of simulated beams vs interpolated beams-->
<resolution>1</resolution>
<!--minimum angle in radians-->
<min_angle>-0.535299248</min_angle>
<!--maximum angle in radians -->
<max_angle>0.18622663</max_angle>
</horizontal>
</scan>
<!-- Range defines characteristics of an individual beam-->
<range>
<!--Minimum distance of the beam-->
<min>0.05</min>
<!--Maximum distance of the beam-->
<max>70</max>
<!--Linear resolution of the beam-->
<resolution>0.02</resolution>
</range>
</ray>
</sensor>
<!-- Vertically offset the top cylinder by the length of the bottom
cylinder and half the length of this cylinder. -->
<pose>0 0 0.095455 0 0 0</pose>
<inertial>
<mass>0.1</mass>
<inertia>
<ixx>0.000090632</ixx>
<iyy>0.000090632</iyy>
<izz>0.000091036</izz>
<ixy>0</ixy>
<ixz>0</ixz>
<iyz>0</iyz>
</inertia>
</inertial>
<collision name="top_collision">
<geometry>
<cylinder>
<!-- Radius and length provided by Velodyne -->
<radius>0.04267</radius>
<length>0.07357</length>
</cylinder>
</geometry>
</collision>
<!-- The visual is mostly a copy of the collision -->
<visual name="top_visual">
<geometry>
<cylinder>
<radius>0.04267</radius>
<length>0.07357</length>
</cylinder>
</geometry>
</visual>
</link>
<!-- Each joint must have a unique name -->
<joint type="revolute" name="joint">
<!--Position the joint at the bottom of the top link -->
<pose>0 0 -0.036785 0 0 0</pose>
<!--Use the base link as the parent of the joint -->
<parent>base</parent>
<!--Use the top link as the child of the joint -->
<child>top</child>
<!--The axis defines the joint`s degree of freedom -->
<axis>
<!--Revolve around the z-axis -->
<xyz>0 0 1</xyz>
<!--limit refers to the range of motion of the joint -->
<limit>
<!--Use a very large number to indicate a continuous revolution -->
<lower>-10000000000000000</lower>
<upper>10000000000000000</upper>
</limit>
</axis>
</joint>
</model>
</world>
</sdf>
更多推荐
gazebo仿真之Velodyne
发布评论