机器人SDF模型写法官方例子

参考：SDFormat官方，里面会写有有什么元素<>可以写

SDF

<?xml version='1.0'?>
<sdf version='1.12'>
  <world name='default'>
    ...
  </world>
</sdf>

or

<?xml version='1.0'?>
<sdf version='1.12'>
  <model name='my_model'>
    ...
  </model>
</sdf>

or 

<?xml version='1.0'?>
<sdf version='1.12'>
  <actor name='my_actor'>
    ...
  </actor>
</sdf>

or

<?xml version='1.0'?>
<sdf version='1.12'>
  <light name='my_light'>
    ...
  </light>
</sdf>

link

<?xml version="1.0" ?>
<sdf version="1.5">
  <model name="box">
    <pose>0 0 0.5 0 0 0</pose>
    <static>false</static>

    <link name="link">
      <pose>0 0 0 0 0 0</pose>
        <inertial>
          <inertia>
            <ixx>1</ixx>
            <ixy>0</ixy>
            <ixz>0</ixz>
            <iyy>1</iyy>
            <iyz>0</iyz>
            <izz>1</izz>
          </inertia>
          <mass>1.0</mass>
        </inertial>

        <collision name="my_collision">
          ...
        </collision>

        <visual name="my_visual">
          ...
        </visual>

        <sensor type="camera" name="my_sensor">
          ...
        </sensor>

    </link>
  </model>
</sdf>

Collision

还有< surface>其中包括了< friction>，< bounce>，< contact>， < soft_contact>

	<collision name="collision">
        <pose>0 0 0.5 0 0 0</pose>
        <geometry>
          <box>
            <size>1 1 1</size>
          </box>
        </geometry>
      </collision>

visual

material等等

      <visual name="visual">
        <pose>0 0 0.5 0 0 0</pose>
        <geometry>
          <box>
            <size>1 1 1</size>
          </box>
        </geometry>
      </visual>

joint

<?xml version="1.0" ?>
<sdf version="1.5">
  <model name="box">

    <link name="link_1">
      ...
    </link>

    <link name="link_2">
      ...
    </link>


    <joint name="bar_12_joint" type="revolute">
      <parent>link_1</parent>
      <child>link_2</child>
      <pose>0 0.5 0 0 0 0</pose>
      <axis>
        <xyz>0 0 1</xyz>
      </axis>
    </joint>

  </model>
</sdf>

sensor

<?xml version="1.0" ?>
<sdf version="1.5">
  <model name="box">
    <link name="link">

        <sensor type="camera" name="my_sensor">
          <camera>
            <horizontal_fov>1.047</horizontal_fov>
            <image>
              <width>320</width>
              <height>240</height>
            </image>
            <clip>
              <near>0.1</near>
              <far>100</far>
            </clip>
          </camera>
          <always_on>1</always_on>
          <update_rate>30</update_rate>
          <visualize>true</visualize>
        </sensor>

    </link>
  </model>
</sdf>

world

< wind>、< gravity>、< magnetic_field>、< atmosphere>、< gui>、< physics>等等

<?xml version="1.0" ?>
<sdf version="1.5">
  <world name="default">
    <physics type="ode">
      ...
    </physics>
    
    <scene>
      ...
    </scene>

    <model name="box">
      ...
    </model>

    <model name="sphere">
      ...
    </model>

    <light name="spotlight">
      ...
    </light>

  </world>
</sdf>